Editor's Note: In the newly launched "Technology Series" of our newspaper's special column "Guo Yuansheng on Sensors," Guo Yuansheng, Deputy Director of the Science and Technology Committee of the Jiusan Society Central Committee and Executive Vice Chairman of the China Sensor and IoT Industry Alliance, will focus on the ten mainstream sensor types: quantum, acoustic, force, optical, gas, magnetic, temperature, humidity, radio frequency (RFID), and biosensors. He will conduct a systematic and accessible in-depth analysis from dimensions such as sensing mechanisms and materials, characteristics and performance indicators, industrial chain and capabilities, technology application status, domestic and international industrial landscape, and future technology development trends. This aims to provide industry practitioners, technical managers, investment institutions, and cross-disciplinary researchers with a technical map that combines professional depth and quick accessibility, helping readers establish a clear knowledge framework and industrial coordinates during the critical period of rapid sensor technology iteration and track switching.
We welcome readers to continue following the "Application Series" and pay further attention to the "Guo Yuansheng on Sensors - Technology Series" to gain a more detailed understanding of the technical systems and underlying logic of sensing mechanisms and materials, as well as sensitive devices and processes. Starting from the most fundamental technologies, readers will comprehend the evolutionary logic and innovative development opportunities of sensing technology.
In the global massive sensor industrialization system, silicon-based semiconductor materials boast the richest sensing mechanisms, the highest device maturity, and the most extensive industrial applications. Relying on four core characteristics—high modifiability, multi-mechanism compatibility, easy micro-nano integration, and easy reading of electrical signals—they have thoroughly broken the performance boundaries and scenario constraints of traditional metal, ceramic, and polymer sensing materials, becoming the cornerstone materials for the omnidirectional intelligent sensing industry. Relying on modification and micro-nano processing technologies, a single material system can meet the omnidimensional sensing needs of physics, chemistry, and biology. Through microstructure regulation, doping modification, and micro-nano processing, they can adapt to all levels of application scenarios, from civilian consumer-grade to aerospace and military-grade. After decades of technology iteration and industrial precipitation, silicon-based semiconductor sensitive materials have formed a complete industrial closed loop of "material iteration - mechanism innovation - process optimization - device fabrication - performance upgrade - scenario landing."
I. Classification and Core Characteristics of Semiconductor Sensitive Materials
Semiconductor sensitive materials are not a single substance but a composite material industry system with clear hierarchies, distinct division of labor, and orderly iteration. According to industrialization maturity, substrate attributes, application positioning, and technology iteration directions, they can be divided into three major levels: main substrates, modified substrates, and extended substrates. The three types of materials perform their respective duties and complement each other: main substrates consolidate the foundation for mass production, modified substrates achieve performance optimization, and extended substrates lay out future frontiers, jointly building the material foundation of the modern semiconductor sensing industry. Meanwhile, semiconductor materials possess unique general attributes that distinguish them from traditional sensing materials, which is also the core root of their ability to monopolize the mainstream sensing market and support all-scenario sensing.
Classification of Core Material Categories
1. Main Substrates: Silicon (Monocrystalline Silicon, Polycrystalline Silicon) — The Absolute Mainstream in the Industry and the Core Foundation of Mass Production
Currently, over 90% of sensitive devices in global commercial sensors use silicon as the core substrate. It is the only semiconductor sensitive material that achieves low-cost, large-scale, and full-category mass production, serving as the basic market for civilian and industrial sensing industries. After half a century of process iteration, the purification, slicing, processing, modification, and packaging processes of silicon materials have been fully standardized, localized, and scaled, possessing strong industrial universality and cost advantages, forming an industrial layout with hierarchical complementarity and scenario segmentation.
From the perspective of sub-categories, monocrystalline silicon and polycrystalline silicon have formed a high-low matching industrial pattern: monocrystalline silicon has regular atomic arrangement, extremely low lattice defects, uniform and stable electrical performance, and minimal signal drift. It is the preferred substrate for high-precision, high-stability, and high-consistency high-end sensors, widely used in high-end scenarios such as aerospace, precision industrial detection, high-end medical equipment, and high-precision navigation; polycrystalline silicon is composed of a large number of tiny monocrystalline grains stacked together, with a small number of grain boundary defects. Its performance is slightly inferior to monocrystalline silicon, but it has a simple preparation process, low production cost, and extremely high mass production efficiency. It fully meets the needs of general scenarios such as civilian consumption and ordinary industrial monitoring, and is the absolute main force in the mid-to-low-end sensing market.
2. Modified Substrates: Doped Silicon, Heavily Doped Silicon, Silicon-Based Composite Structures — The Core Carrier for Performance Upgrades
Pure silicon substrates are limited by intrinsic physical properties, suffering from limited sensitivity, large temperature drift, and single sensing dimensions. They have natural performance shortcomings and cannot meet the high-end needs of high precision, extreme working conditions, and multi-parameter detection. Modification technology based on pure silicon substrates has become the core path for the performance leap of silicon-based materials and adaptation to mid-to-high-end scenarios, and is also the core preparation scheme for current mainstream commercial sensors. Modified substrates do not change the basic process system of silicon, but only achieve performance upgrades through micro-doping and structural compounding, featuring strong compatibility, low landing cost, and high industrialization maturity.
Doped silicon is currently the most widely used modified material. By injecting impurity atoms such as boron and phosphorus into the silicon lattice, it precisely regulates the conductivity type and carrier concentration of silicon, significantly improving sensing sensitivity and reducing temperature drift, adapting to most commercial mechanisms such as pressure, temperature, photoelectric, and gas sensitivity; heavily doped silicon adopts ultra-high concentration precise doping processes, breaking the performance limit of traditional doping, expanding the infrared sensing boundary, and improving extreme environment stability, mostly used in high-end industrial and special sensing scenarios; silicon-based composite structures compound silicon with silicon dioxide, silicon nitride, functional metal films, and polymer coatings, making up for the shortcomings of pure silicon such as weak anti-interference, poor specificity, and insufficient corrosion resistance, achieving a dual upgrade of sensing performance and environmental adaptability.
3. Extended Substrates: Wide Bandgap Semiconductors, 2D Semiconductor Materials — The Core Direction for Frontier Advancement
As intelligent sensing extends to extreme environments, ultra-high precision, flexible adaptation, and multi-modal synchronous detection scenarios, the intrinsic bottlenecks of traditional silicon-based materials are becoming increasingly prominent, unable to adapt to high-end scenarios such as high temperature, high pressure, strong radiation, ultra-weak signal detection, and flexible curved surface attachment. New extended substrates represented by wide bandgap semiconductors and 2D semiconductors have become the core direction for mid-to-long-term technology iteration in the industry. They are currently in the transition stage of "laboratory breakthrough - small-batch trial production - preliminary commercialization," and are the core track for overtaking on the curve, domestic substitution, and independent controllability in the future high-end sensing industry.
Wide bandgap semiconductors, with silicon carbide and gallium nitride as the core, possess the characteristics of high temperature resistance, high voltage resistance, radiation resistance, and strong chemical stability, and can adapt to extreme working conditions in aerospace, nuclear industry, high-temperature metallurgy, and new energy; 2D semiconductor materials, represented by graphene, MXene, and transition metal dichalcogenides, have the advantages of atomic-level ultra-thin structure, ultra-large specific surface area, ultra-high sensitivity, and flexible deformation. They perfectly adapt to emerging scenarios such as flexible wearables, non-invasive medical treatment, and ultra-trace environmental detection, and are the core materials for next-generation intelligent sensing, bionic electronic skin, and precision medical sensing.
Material Characteristics
Whether it is mature silicon-based substrates, modified materials, or frontier new semiconductor material systems, they all possess four major general core characteristics.
1. Precise regulation of carrier concentration. The conductive and sensing performance of semiconductor materials entirely relies on the regulation of carrier (electrons, holes) concentration. Tiny external changes and fluctuations in pressure, temperature, light, gas, and ions can cause regular fluctuations in the carrier concentration inside the material by changing the lattice structure and surface charge distribution state, which are then converted into readable electrical signals. They possess the ability to highly sensitively capture weak signals, which is a core advantage that traditional materials do not have.
2. Multi-dimensional physical properties can be modified and upgraded. Through processes such as doping, structural reconstruction, surface modification, and heterojunction compounding, the electrical, optical, magnetic, and thermal characteristics of semiconductor materials can be precisely changed, enabling a single material to be compatible with multi-dimensional sensing mechanisms of mechanics, optics, thermodynamics, chemistry, and magnetism, thoroughly solving the limitation of "one material, one mechanism" in traditional materials.
3. Perfect adaptation to the MEMS micro-nano processing system. Semiconductor materials are highly compatible with existing IC (Integrated Circuit) and MEMS micro-electromechanical processes. They can precisely process various sensitive microstructures at the micro and nanometer scales, achieving device miniaturization, arraying, low power consumption, and high integration, adapting to lightweight scenarios such as smartphones, wearable devices, and micro-precision instruments.
4. Support for monolithic integrated intelligence. Semiconductor sensitive materials can be directly monolithically integrated with signal amplification, filtering, analog-to-digital conversion, and control circuits, realizing the integration of "sensing + processing + output" without the need for additional external circuits. This greatly simplifies the device structure, reduces mass production costs, and improves system stability, laying the hardware foundation for sensing intelligence.
Relying on the four core characteristics, semiconductor materials have ultimately achieved omnidimensional and omnidirectional sensing of physics, chemistry, and biology, covering the needs of all scenarios in civilian, industrial, medical, aviation, and environmental fields.
Differentiated Advantages Compared to Other Sensing Materials
Before the popularization of semiconductor materials, the sensing industry long relied on the three major traditional material systems of metal, ceramic, and polymer. However, all three types of materials have shortcomings such as single mechanisms, performance limitations, and restricted scenarios, unable to support omnidirectional intelligent sensing.
Comprehensive comparison shows that the core differentiated advantages of semiconductor sensitive materials are irreplaceable: it is the only sensing material system that achieves multi-mechanism sensing with a single material, high-precision sensitive detection, micro-nano integrated mass production, and all-scenario adaptation. This is also the fundamental reason why it can firmly occupy the core position in the global sensing industry and support omnidirectional sensing in the intelligent era.
II. Mature Sensitive Mechanisms, Characteristics, and Corresponding Components of Semiconductor (Silicon-Based) Materials
Currently, there are only seven types of silicon-based sensitive mechanisms in the industry that can truly achieve large-scale mass production, commercial landing, and adaptation to all-scenario applications. They have complementary performance, synergistic functions, and segmented scenarios, jointly covering the omnidimensional sensing needs of mechanics, environment, optics, magnetism, chemistry, and infrared.
Piezoresistive Mechanism and Value Advantages
From the perspective of mechanism characteristics, monocrystalline silicon materials possess a strong piezoresistive effect, which is an intrinsic attribute inherent to silicon materials. When silicon microbeams, silicon thin films, and silicon microstructures are subjected to external compression, stretching, twisting, and fluid impact, the microscopic lattice structure will undergo uniform, reversible elastic deformation, and the atomic spacing will shift regularly, directly changing the migration efficiency of carriers inside the silicon and the overall resistivity. The magnitude of the external force, the degree of deformation, and the change in resistivity show a highly linear corresponding relationship, ultimately achieving precise, reversible, and stable conversion of mechanical signals into electrical signals.
Compared with traditional metal strain mechanisms, the sensitivity of the silicon-based piezoresistive mechanism is increased by 50 to 100 times. It has excellent linearity, simple structure, no hysteresis error, and is compatible with MEMS micro-nano processing. It can achieve extreme miniaturization and array preparation, and is the core technology with the earliest industrialization, largest application scale, and most mature landing among all mechanical sensors. The biggest advantage is controllable cost, high consistency, and strong stability, fully adapting to large-scale mass production. This mechanism accounts for more than 60% of the global commercial semiconductor sensor market and is widely used in consumer electronics, industrial intelligent manufacturing, automotive electronics, high-end equipment, and other fields.
Corresponding commercial components and landing scenarios: silicon pressure sensors, acceleration sensors, gyroscopes, flow/level sensors. Among them, silicon pressure sensors are widely used in smartphone air pressure detection, automotive tire pressure monitoring, industrial pipeline pressure monitoring, and medical blood pressure equipment; acceleration sensors and gyroscopes support mobile phone step counting, screen rotation, drone attitude control, automotive airbag triggering, and VR/AR spatial positioning; flow and level sensors can realize real-time monitoring of industrial fluid flow and water tank reservoir levels.
Carrier Concentration Regulation Mechanism and Value Advantages
The carrier concentration regulation mechanism is the core support for silicon-based environmental sensing, and is also the second largest commercial mainstream mechanism next to the piezoresistive mechanism, specifically adapting to the detection of three major environmental parameters: temperature, gas, and humidity. Its core mechanism logic is easy to understand: there are a large number of dangling bonds and active sites on the surface of silicon materials, and the surface carrier concentration is in a dynamic equilibrium state, which is extremely susceptible to interference from external environmental parameters. When the ambient temperature rises, the thermal motion of carriers inside the silicon intensifies, and the number increases exponentially, causing the resistance to drop synchronously; when the ambient humidity changes, water molecules adsorb on the silicon surface and ionize, changing the surface charge distribution and carrier concentration; when gases such as formaldehyde, VOC, and carbon monoxide in the air adsorb or detach from the silicon surface, they will capture or release electrons, directly causing regular shifts in electrical parameters. By capturing subtle changes in resistance, current, and voltage through chips, environmental data such as temperature, humidity, and gas concentration can be accurately converted.
This mechanism has a simple structure, fast response speed, no need for complex structural design, and extremely low mass production cost. It is the preferred technical solution for civilian environmental sensing devices, with high overall industrialization maturity, good batch consistency, and extremely high market penetration rate. The only shortcoming is that it is susceptible to cross-interference in high-precision scenarios, which can be effectively solved through algorithm compensation and surface modification process optimization, further improving detection accuracy and environmental anti-interference capability.
Corresponding commercial components and landing scenarios: silicon-based temperature sensors, gas-sensitive sensors, and humidity-sensitive sensors. Among them, silicon-based temperature sensors are used for smart wearable body temperature monitoring, home appliance temperature control, industrial furnace temperature detection, and aviation equipment temperature collection; gas-sensitive sensors are used for indoor air purification, smart home gas warning, chemical workshop gas leak monitoring, and industrial exhaust gas detection; humidity-sensitive sensors are used for meteorological monitoring, agricultural greenhouse regulation, industrial precision equipment moisture prevention, and warehouse environment monitoring.
Photoelectric Conversion Mechanism and Value Advantages
The photoelectric conversion mechanism is the core mainstream mechanism for silicon-based optical sensing. Relying on the two mature physical effects of the photovoltaic effect and the photoconductive effect, it can achieve efficient and stable conversion of optical signals into electrical signals, comprehensively covering omnidimensional optical sensing scenarios such as light intensity detection, color recognition, spectral analysis, imaging acquisition, and radiation monitoring. It is the core technical foundation for consumer electronics optical systems, industrial vision detection, and precision optical instruments. Its core mechanism characteristics are stable and reliable: when visible light, ultraviolet light, and near-infrared light of specific bands irradiate silicon-based sensitive microstructures, the photon energy will break the outer electron binding of silicon atoms, exciting the generation of a large number of electron-hole pairs, significantly increasing the carrier concentration of the material, and orderly changing the conductive characteristics and output electrical parameters of the device. Among them, the photoconductive effect can achieve continuous and precise detection of light intensity, and the photovoltaic effect can achieve passive photoelectric signal conversion and imaging detection. Light intensity, spectral bands, and device output electrical signals have a highly linear corresponding relationship, which can complete the quantitative identification and precise analysis of multi-dimensional optical information.
Compared with traditional optical sensing materials, the response speed of the silicon-based photoelectric conversion mechanism can reach the nanosecond level. It has comprehensive advantages such as high sensitivity, good linearity, excellent repeatability, simple structure, and easy micro-nano integration, and can adapt to high-frequency, dynamic, and high-precision optical detection scenarios. At the same time, this mechanism is highly compatible with existing MEMS and CMOS processes, can achieve large-scale array integrated mass production, and has outstanding cost-effectiveness advantages. It is currently the most mature and widely applied core technology in the global commercial optical sensing field, supporting the large-scale development of the global image sensing, optical detection, and radiation protection industries for a long time.
Corresponding commercial components and landing scenarios: photoelectric sensors, color-sensitive sensors, CMOS image sensors, and radiation sensors. Among them, photoelectric sensors are used for mobile phone ambient light sensing, industrial object counting, and smart home human body induction; color-sensitive sensors achieve screen color calibration, industrial color difference detection, and precise color tuning of light sources; CMOS image sensors are the core imaging devices for mobile phone cameras, monitoring equipment, industrial vision, and medical endoscopes; radiation sensors are used for precise monitoring of environmental ultraviolet radiation, industrial flaw detection radiation, and medical radiotherapy radiation.
Tunneling Magnetoresistance Mechanism and Value Advantages
The tunneling magnetoresistance mechanism is an advanced commercial mechanism for silicon-based high-end magnetic sensitive sensing, mainly adapting to weak magnetic field detection, spatial geomagnetic sensing, and precision position and current detection scenarios. It is an iterative upgrade solution for traditional Hall sensing technology. Its core mechanism characteristics are clear and stable: through mature silicon-based MEMS micro-nano processing technology, a nanoscale magnetic tunnel junction composite structure of "ferromagnetic layer - insulating layer - ferromagnetic layer" is constructed on the silicon substrate, forming a magnetically sensitive unit with stable structure and uniform performance. When the external magnetic field strength and magnetic field direction undergo subtle changes, the magnetization angles of the upper and lower ferromagnetic thin films produce relative offsets, directly changing the transmission probability of electrons tunneling through the ultra-thin insulating layer, causing regular and quantifiable large fluctuations in the overall resistance value of the device. The magnetic field parameters and electrical output signals have a precise corresponding relationship, enabling high-precision capture and analysis of ultra-weak magnetic field signals.
Compared with the traditional Hall magnetic sensing mechanism, the silicon-based tunneling magnetoresistance mechanism has significant comprehensive performance advantages. The magnetic field detection sensitivity is increased by 10 to 100 times, which can capture weak geomagnetic fluctuations and subtle magnetic field changes that conventional devices cannot recognize. At the same time, it has the characteristics of lower power consumption, smaller size, stronger anti-electromagnetic interference capability, and better temperature stability. The structure of this mechanism adapts to miniaturized and chip-based integrated design, with mature mass production processes and good batch consistency. It perfectly adapts to the high-precision magnetic sensing needs of high-end intelligent equipment, automotive electronics, and industrial precision control, and is the core technical direction for high-end iteration in the current magnetic sensitive sensing field.
Corresponding commercial components and landing scenarios: high-sensitivity silicon-based magnetic sensitive sensors and magnetic field detection chips. Among them, high-sensitivity silicon-based magnetic sensitive sensors are used for precise calibration of industrial equipment positions, dynamic detection of motor speed, and current monitoring of power systems; magnetic field detection chips are widely used in scenarios such as mobile phone electronic compasses, drone geomagnetic navigation, industrial magnetic field distribution detection, and precise control of smart home appliance switches.
Ion Surface Potential Mechanism and Value Advantages
The ion surface potential mechanism is the core mature mechanism for silicon-based chemical sensing and biological trace sensing, specifically adapting to ion concentration detection in aqueous solutions, soil, human body fluids, and chemical electrolytes. It is the core commercial technology in the fields of environmental monitoring, modern agriculture, in vitro diagnosis, and precision medicine, with stable industrialization landing, strong detection specificity, and high trace detection accuracy. Its core mechanism logic is clear and controllable: the surface of silicon-based devices is naturally covered with a dense silicon dioxide passivation layer, possessing rich surface active sites and extremely strong ion adsorption and charge exchange capabilities; when the sensitive unit contacts various ion-containing solution systems, hydrogen ions, heavy metal ions, potassium, sodium, and calcium electrolyte ions in the solution will undergo specific charge exchange with the silicon surface, directly changing the surface potential and interface impedance of the material. The higher the ion concentration in the solution, the more significant the surface potential shift, and the two show a stable linear corresponding relationship, enabling precise quantitative identification of various ion signals.
Compared with traditional chemical and ion detection technologies, the silicon-based ion surface potential mechanism has outstanding advantages. It does not require complex chemical reactions or labeling reagents, and has a fast detection response speed, enabling real-time, in-situ, and non-invasive detection of trace samples. At the same time, this mechanism is compatible with MEMS micro-nano processing and can achieve chip-level miniaturized integration, thoroughly solving the industry pain points of traditional chemical detection equipment such as bulkiness, detection lag, high cost, and inability to monitor online in real time. It adapts to the needs of large-scale mass production and multi-scenario embedded detection, and has extremely high commercial landing value.
Corresponding commercial components and landing scenarios: Ion-Sensitive Field-Effect Transistors (ISFET) and silicon-based chemical ion sensors. Among them, ISFETs are used for precise detection of water quality pH value, heavy metal ions, and ammonia nitrogen content; silicon-based chemical ion sensors are widely used in scenarios such as clinical electrolyte detection, soil fertility ion monitoring, industrial wastewater pollutant detection, and trace analysis of food additives.
Micro-Mechanical Optical Modulation Mechanism and Value Advantages
The micro-mechanical optical modulation mechanism is the core commercial mechanism for silicon-based precision optical regulation and ultra-high precision physical detection. Relying on the coupling effect of MEMS micro-mechanical deformation and optical modulation, it breaks through the accuracy limit of traditional single optical and mechanical sensing, specifically adapting to nanoscale precision detection, high-end optical regulation, precision displacement, and micro-vibration monitoring scenarios. It has currently achieved full-process industrialization landing and large-scale commercialization. Its core mechanism characteristics are extremely advantageous: silicon materials possess excellent micro-nano machinability and reversible elastic deformation, and can precisely prepare movable microstructures such as micro-scale cantilever beams, thin films, and gratings on silicon substrates; when external pressure, vibration, and temperature changes cause nanoscale subtle deformations in the microstructures, it will precisely change the propagation path, phase distribution, reflection intensity, and transmission efficiency of incident light, achieving high-precision controllable modulation of optical signals. Through reverse analysis of backend optical signals, physical parameters such as micro structural deformation, precision displacement, high-frequency vibration, and subtle stress can be accurately deduced, and the detection accuracy can reach the nanoscale.
This mechanism innovatively integrates the dual advantages of silicon-based mechanical sensing and optical sensing. Its detection accuracy, resolution, and stability far exceed those of single sensing mechanisms. It has the characteristics of strong anti-interference capability, reversible deformation, excellent repeatability, and stable long-term operation. Relying on mature silicon-based micro-nano processing technology, device miniaturization, arraying, and high-consistency mass production can be achieved. It is an irreplaceable core commercial technology in the fields of high-end precision instruments, optical fiber communication, laser detection, and aviation optical monitoring.
Corresponding commercial components and landing scenarios: silicon-based micro-optical modulation sensors and precision optical detection units. Among them, silicon-based micro-optical modulation sensors are used for precise modulation of optical signals in optical fiber communication, laser interferometry, and dynamic monitoring of optical attitude in aerospace; precision optical detection units are used in scenarios such as industrial precision dimension detection, medical optical coherence tomography, scientific research precision optical experiments, and long-term monitoring of nanoscale deformation of equipment.
Pyroelectric Mechanism and Value Advantages
The pyroelectric mechanism is the core mature mechanism for silicon-based infrared thermal radiation sensing. It focuses on room-temperature passive infrared detection, requiring no low-temperature cooling assistance. It can stably adapt to scenarios such as infrared light sensing, thermal radiation collection, non-contact temperature measurement, and thermal imaging monitoring. It is the core technical foundation for infrared sensing with the largest mass production scale and highest cost-effectiveness in the fields of civilian consumption, industrial detection, and security night vision. Its core mechanism characteristics are stable and reliable: the silicon-based pyroelectric thin film, after precise doping and modification, has stable spontaneous polarization charges inside and is in a dynamic equilibrium state of charges under normal conditions; when external infrared thermal radiation irradiates the material surface, the thin film temperature undergoes micro dynamic changes, thoroughly breaking the original polarization charge balance, causing regular fluctuations in the induced charge density on the material surface, and outputting weak current and voltage signals that can be accurately captured. Among them, the infrared radiation intensity, target heat source temperature, and device electrical output signals are highly corresponding, enabling high-precision, non-contact infrared temperature measurement and omnidirectional thermal imaging detection.
Compared with traditional infrared sensing technologies, the silicon-based pyroelectric mechanism has a simple structure, low preparation cost, fast response speed, and extremely strong room-temperature working stability. It does not require the assistance of complex cooling systems, greatly reducing device size, power consumption, and mass production costs. At the same time, this mechanism is compatible with standardized MEMS batch processes, has good product consistency and strong environmental adaptability, and can be landed on a large scale in all civilian and industrial scenarios. It is currently the most mature and highest market penetration core technology in the commercialization of the infrared sensing industry.
Corresponding commercial components and landing scenarios: silicon-based infrared sensitive sensors and infrared temperature measurement detection units. Among them, silicon-based infrared sensitive sensors are used for forehead thermometer body temperature measurement, smart home human body infrared induction, night vision security detection, and automotive night vision assisted driving; infrared temperature measurement detection units are used in scenarios such as thermal imaging inspection of power equipment, overheat warning of industrial high-temperature equipment, building energy conservation detection, and full-process temperature monitoring of automated production lines.
III. Core Process Routes for the Device Integration of Semiconductor Sensitive Materials
High-quality high-purity silicon wafers cannot be directly used for signal detection. A complete, standardized, and closed-loop device integration process is required to manufacture commercial, highly stable, high-precision, and standardized sensing devices. After decades of industrial iteration, six core process chains have now been formed: substrate pretreatment, micro-nano structure processing, material modification, surface functionalization, heterojunction epitaxy, and packaging integration. These directly determine the sensitivity, stability, consistency, yield rate, and service life of the devices, and are the core bridge for the value landing of the silicon-based sensing industry.
Substrate Pretreatment: Purification, Polishing, and Stress Relief Treatment of Monocrystalline Silicon Wafers
Substrate pretreatment is the first process and a key prerequisite for determining the basic performance and mass production yield rate of devices. Untreated native silicon wafers have problems such as excessive impurities, rough surfaces, uneven internal stress, and excessive lattice defects. Direct processing will lead to device signal drift, poor consistency, and extreme susceptibility to failure, making them uncommercializable. The pretreated silicon substrate has the characteristics of high purity, high flatness, low defects, and low stress, which is the basic guarantee for all subsequent precision processes.
The core process flow of this technology includes four major links: first, high-purity purification, purifying industrial-grade silicon to electronic-grade ultra-high-purity silicon with a purity of over 99.9999%, thoroughly removing metal and non-metal impurities, and eliminating carrier disorder and signal errors caused by impurities; second, precision slicing, cutting silicon ingots into silicon wafers with uniform thickness to ensure the thickness consistency of the entire substrate, laying the foundation for subsequent micro-nano processing; third, chemical mechanical polishing, achieving nanoscale surface flatness through the CMP process, eliminating surface scratches, micro-protrusions, and defects, and ensuring the accuracy of lithography and thin film deposition; fourth, high-temperature annealing stress relief, releasing the internal mechanical stress generated during the cutting and polishing of silicon wafers through high-temperature heat treatment at 500-800°C, avoiding bending, cracking, and deformation in subsequent processing, and greatly improving the long-term stability of devices.
Micro-Nano Structure Processing: MEMS Etching, Thin Film Deposition, and Microstructure Formation (Core Process)
MEMS micro-nano processing is the core process for semiconductor sensitive devices to achieve miniaturization, arraying, and high precision. It is the core technical barrier for silicon-based sensing devices, directly determining the sensing accuracy, volume size, and integration degree. Relying on MEMS micro-nano processes, micro and nanoscale sensitive microstructures can be processed on millimeter-scale silicon wafers, achieving extreme device lightweighting and ultra-high precision sensing.
Its process flow is divided into three major modules: first, lithography patterning, accurately transferring the designed microstructure drawings to the silicon wafer surface through coating, exposure, and development processes to form a precise protective template; second, precision etching, using a combination of dry plasma etching and wet chemical etching to accurately remove excess silicon material, processing core sensitive structures such as silicon beams, silicon films, microelectrodes, and micro-grooves, with accuracy reaching the micrometer level; finally, thin film deposition and structure formation, depositing insulating thin films and electrode thin films through CVD, PVD, and sputtering processes, combined with sacrificial layer etching and wafer bonding processes, to release suspended deformable microstructures, enabling the sensitive units to have deformation sensing capabilities.
Modification Process: Ion Implantation and High-Temperature Doping for Precise Regulation of Carrier Characteristics
The intrinsic performance of pure silicon substrates has obvious shortcomings, such as low sensitivity, large temperature drift, and poor sensing specificity. Through manual intervention, the carrier concentration, conductivity type, and sensitive characteristics of silicon materials can be precisely regulated. Through the modification process, the piezoresistive sensitivity, photoelectric response efficiency, gas sensitivity specificity, and temperature stability of silicon materials can be targetedly improved, which is the core means for device performance upgrades.
Currently, the mainstream industrial modification processes are divided into two categories: first, the ion implantation process, which relies on high-energy ion beams to accurately inject impurity ions such as boron, phosphorus, and arsenic into designated areas of the silicon wafer. It can precisely control the doping depth and doping concentration, adapt to the preparation of high-end high-precision sensors, and has high temperature drift control accuracy and good performance consistency; second, the high-temperature diffusion doping process, which introduces impurity gases into a high-temperature furnace at 900-1200°C to achieve large-area uniform doping. The process is simple and the cost is low, adapting to the mass production of civilian general-purpose sensors.
Surface Functionalization: Surface Passivation, Thin Film Coating, and Functional Coating Modification
The native surface of silicon materials has a large number of dangling bonds, lattice defects, and active sites, which are extremely easy to adsorb water vapor, dust, and harmful gases. Long-term use will lead to problems such as signal drift, leakage, performance degradation, and poor specificity, seriously affecting the service life and detection accuracy of devices. The surface functionalization process is to seal defects and isolate interference. It is the core process to solve the poor long-term stability, weak anti-interference, and insufficient specificity of devices, and can increase the service life of devices several times.
The core of the process is divided into three major directions: first, surface passivation, depositing dense silicon dioxide and silicon nitride thin films to seal surface defects, isolate external water vapor, oxygen, and corrosive media, greatly reducing signal drift and improving the long-term stability of devices; second, flexible thin film coating, depositing flexible materials such as polyimide and silicone rubber to protect micro-nano structures and improve the impact resistance and bending resistance of devices; third, functional coating modification, modifying platinum and palladium catalytic coatings, biological probe coatings, and specific adsorption coatings according to detection needs, to improve gas detection selectivity, biological signal recognition capability, and chemical sensing accuracy.
Heterojunction Epitaxy: Multi-Layer Semiconductor Epitaxial Growth to Build Composite Sensitive Structures
Single silicon-based materials have a performance limit and cannot adapt to the high-end needs of extreme working conditions, multi-parameter synchronous detection, and ultra-high precision sensing. The heterojunction epitaxy process is the core preparation technology for high-end sensors and special sensing devices. By epitaxially growing semiconductor thin films with different bandgaps and different physical properties on the silicon substrate, a composite heterojunction structure is constructed to achieve performance complementarity, mechanism expansion, and scenario upgrading.
Relying on MOCVD and MBE precision epitaxial processes, new semiconductor thin films such as silicon carbide, gallium nitride, and indium gallium arsenide can be precisely grown at the nanoscale on the silicon wafer surface, forming a composite structure with stable lattice matching. This composite structure not only retains the advantages of mature silicon-based processes, easy integration, and controllable costs, but also has the characteristics of new materials such as high temperature resistance, radiation resistance, wide spectrum response, and multi-mechanism compatibility. It can achieve synchronous force and temperature detection, multi-band photoelectric sensing, and stable working in extreme environments, greatly expanding the application boundaries of devices.
Packaging Integration: Chip Packaging and Signal Circuit Integration to Achieve Commercial Landing
The bare chip structure after micro-nano processing and modification is fragile, unprotected, and lacks signal processing capabilities, making it uncommercializable directly. Packaging integration is the last step of device integration and a key link connecting bare chip components and terminal applications. Its core function is to protect the chip, integrate circuits, and standardize output signals.
The process flow includes three major links: packaging protection, circuit integration, and calibration testing: first, chip packaging, fixing the chip through plastic, ceramic, and metal packaging processes, bonding wires, and isolating external physical and chemical damage; second, signal integration, integrating amplification, filtering, analog-to-digital conversion, and compensation circuits onto the substrate to achieve standardized processing of sensing signals; third, whole machine calibration, performing algorithm calibration for temperature drift, linearity, and sensitivity deviations, correcting device errors, and ensuring batch product consistency. After packaging integration, bare chips are finally transformed into standardized commercial sensors that can be directly connected to terminal equipment.
IV. Core Performance Evaluation Indicators for Semiconductor Sensitive Devices
Currently, the industry has formed a complete evaluation system with five major dimensions: core sensing performance, stability indicators, response characteristics, range characteristics, and environmental adaptability. All indicators have clear parameter standards, industry pain points, and application value, and are the core basis for product R&D, mass production quality inspection, and terminal selection.
Core Sensing Performance: Sensitivity, Detection Limit, and Resolution
Core sensing performance determines the sensing acuity and fineness of the device. It is the basic indicator for measuring the accuracy grade of sensors and directly distinguishes ordinary civilian devices from high-end precision devices.
1. Sensitivity. Refers to the change in electrical signal output corresponding to a unit change in external signal, representing the acuity of the device in capturing signals. The typical sensitivity of silicon-based piezoresistive sensors is 1-5mV/kPa, and photoelectric sensors can reach 0.5-2A/W. The higher the sensitivity, the stronger the ability to capture weak signals.
2. Detection limit. It is the minimum signal threshold that the device can stably recognize, representing the ultimate sensing capability. The detection limit of high-quality silicon-based pressure sensors can reach 0.1Pa, temperature sensors can reach 0.01°C, and gas-sensitive sensors can recognize trace gases at the 1ppm level. It is the core guarantee for trace detection and precision monitoring.
3. Resolution. Represents the minimum signal change that the device can distinguish, determining the fineness of sensing. High-end industrial-grade devices can achieve a pressure resolution of 0.01kPa and a temperature resolution of 0.01°C, fully adapting to precision industrial detection and high-end instrument scenarios.
Stability Indicators: Temperature Drift Coefficient, Long-Term Working Stability, and Repeatability
Stability is the most core, critical, and defect-prone indicator for semiconductor sensors. It is also the core gap between domestic devices and international high-end devices, directly determining the commercial reliability and service life of devices.
1. Temperature drift coefficient. It is the biggest pain point in the industry, referring to the signal shift amount for every 1°C change in temperature. The temperature drift of ordinary civilian silicon force-sensitive sensors is ±0.1%FS/°C, industrial-grade can be controlled at ±0.02%FS/°C, and aerospace-grade high-end devices can be as low as 5ppm/°C. The intrinsic temperature sensitivity of silicon materials makes it impossible to completely eliminate temperature drift. It can only be optimized through material modification and algorithm compensation, which is the core direction for tackling high-end sensing technology.
2. Long-term working stability. Refers to the performance retention rate of the device after long-term continuous operation. The performance retention rate of civilian devices after one year is ≥85%, the stable working retention rate of industrial-grade after five years is ≥95%, and high-end aerospace-grade devices can achieve ten years of long-term stability. It is the core guarantee for long-term monitoring of industrial equipment and high-end equipment.
3. Repeatability. Refers to the consistency of multiple measurement data under the same working conditions. The repeatability of civilian-grade is ≤±0.5%FS, and industrial-grade is ≤±0.1%FS. The better the repeatability, the higher the data credibility and the more stable the equipment control accuracy.
Response Characteristics: Response Time and Recovery Time
Response characteristics determine the dynamic sensing capability and real-time performance of the device, adapting to high-frequency dynamic monitoring and real-time control scenarios.
1. Response time. It is the time for the device to output a stable signal after the external signal changes. The response time of silicon-based photoelectric sensors can reach the microsecond level, piezoresistive sensors are at the millisecond level, and gas-sensitive sensors are at the second level;
2. Recovery time. It is the time for the device to return to the initial state after the signal disappears. The faster the recovery speed, the stronger the dynamic cyclic sensing capability, adapting to high-frequency scenarios such as drone attitude control, equipment dynamic monitoring, and real-time physiological signal acquisition.
Range Characteristics: Linearity, Measurement Range, and Overload Capability
Range characteristics determine the breadth of scenario adaptation and quantification accuracy of the device.
1. Linearity. Represents the fitting accuracy of input and output signals. The smaller the linearity error, the more accurate the data and the lower the calibration cost. The linearity of industrial-grade devices can be controlled within ±0.1%FS;
2. Measurement range. Covers the full range of micro-pressure, normal pressure, high pressure, low temperature, and high temperature, and can adapt to different working condition needs;
3. Overload capability. Represents the ability of the device to resist sudden impacts. High-quality devices can withstand 2-5 times (or even higher) range overload, effectively avoiding device damage caused by sudden industrial pressure and temperature shocks.
Environmental Adaptability: Anti-Interference, Temperature and Humidity Tolerance, and Corrosion Resistance
Environmental adaptability determines the working capability of the device under complex working conditions.
1. Anti-interference capability. Reflects the level of the device's resistance to electromagnetic, vibration, and dust interference. Industrial-grade devices can meet strict electromagnetic compatibility standards;
2. Temperature and humidity tolerance range. Covers the full temperature range of civilian, industrial, and aerospace applications. High-end devices can work stably in a wide temperature range of -60°C to 150°C;
3. Corrosion resistance determines the service life of the device in environments with salt spray, acid and alkali, and harmful gases. It is the core guarantee for chemical, marine, and outdoor monitoring scenarios.
V. All-Scenario Landing Application Fields
Semiconductor sensitive materials have achieved large-scale landing across all industries and all scenarios, thoroughly penetrating the core fields of the national economy and high-end equipment, forming five major core application tracks: consumer electronics, industrial intelligent manufacturing, medical health, aerospace, and environmental monitoring.
Consumer Electronics: Omnidirectional Sensing Empowers Smart Terminal Interaction Upgrades
Consumer electronics is the track with the largest industrialization scale and most mature landing for semiconductor sensitive materials. It is the core foundation for smart terminals to achieve human-computer interaction, intelligent sensing, and scenario self-adaptation. Every smartphone, smart wearable, and smart home device integrates multiple silicon-based sensors to achieve omnidimensional environmental and attitude sensing.
In the field of smartphones, accelerometers, gyroscopes, and magnetic sensitive sensors achieve screen rotation, step counting, navigation, anti-shake, and spatial positioning; CMOS image sensors and photoelectric sensors support image imaging, ambient light self-adaptation, and under-screen fingerprint unlocking; air pressure, temperature, and humidity sensors achieve altitude measurement, equipment overheat protection, and environmental monitoring, building a full-scenario intelligent sensing system for mobile phones.
In the field of wearable devices, photoelectric sensors monitor heart rate and blood oxygen, temperature sensors collect human body temperature, and pressure sensors recognize sleep posture and exercise status, achieving 24/7 non-invasive health monitoring and becoming a core tool for public daily health management. In the field of smart homes, temperature, humidity, gas, and human body induction sensors achieve environmental self-adaptive regulation, safety warning, and imperceptible interaction, promoting the intelligent upgrade of home scenarios.
Industrial Intelligent Manufacturing: Supporting Industrial Precision Control and Intelligent Operation and Maintenance
Industrial intelligent manufacturing is the core track for the high-end and high-precision application of semiconductor sensitive materials. It is the core underlying support for industrial automation, intelligent operation and maintenance, safe production, and quality and efficiency improvement. The monitoring of process parameters, equipment status warning, and plant safety protection throughout the entire industrial production process all rely on the precise, stable, and long-term sensing of silicon-based sensors.
In production process control, pressure, temperature, flow, and level sensors monitor the core process parameters of reactors, pipelines, and production lines in real time, ensuring production standardization and product consistency; in the field of intelligent equipment operation and maintenance, vibration and strain sensors capture the operating status of motors, fans, and machine tools in real time, warning of fatigue wear and structural deformation failures in advance, achieving predictive maintenance and greatly reducing industrial downtime losses; in the field of safe production, gas-sensitive, temperature, and humidity sensors monitor toxic and harmful gases and temperature and humidity abnormalities in real time, achieving leak warning and fire prediction, building a solid industrial safety production defense line, and helping the industry fully transform from manual extensive control to precise intelligent automatic control.
Medical Health: Opening a New Era of Non-Invasive Precision Monitoring
Medical health is the core track with the highest added value and greatest development potential for semiconductor sensitive materials. It has thoroughly broken the shortcomings of traditional medical monitoring equipment such as bulkiness, invasiveness, intermittence, and high cost, achieving home-based, non-invasive, long-term, and precise physiological signal monitoring, supporting the rapid development of smart medical care, precision medical care, and rehabilitation medical care.
In the field of daily health monitoring, silicon-based photoelectric and temperature sensors achieve normalized monitoring of body temperature, heart rate, and blood oxygen; in the field of in vitro diagnosis, ion-sensitive sensors accurately detect blood glucose, electrolytes, heavy metals, and body fluid ion concentrations, supporting home rapid testing and clinical screening; in the field of rehabilitation medical care, posture and pressure sensors capture human joint movement and muscle contraction status, assisting in postoperative rehabilitation evaluation and training guidance; in the field of high-end medical care, miniaturized silicon-based sensing units can be implanted inside devices to achieve minimally invasive physiological signal monitoring, providing continuous data support for clinical diagnosis and condition warning, and comprehensively protecting human health.
Aerospace and High-End Equipment: Core Support for Precision Sensing in Extreme Environments
Aerospace and high-end equipment are the top application scenarios with the highest technical barriers and most stringent performance requirements for semiconductor sensitive materials. Aircraft, satellites, rockets, and high-end special equipment work in extreme environments such as extreme cold, high temperature, strong radiation, high vibration, and vacuum for a long time. They put forward ultimate requirements for the accuracy, stability, anti-interference, and weather resistance of sensors. High-end silicon-based and wide bandgap semiconductor materials are the only core sensing substrates that can be adapted.
In the field of aircraft control, high-precision gyroscopes, accelerometers, and magnetic sensitive sensors achieve attitude sensing, heading calibration, and autonomous navigation to ensure flight stability; in the field of environmental monitoring, pressure, temperature, and infrared sensors achieve parameter collection in extreme environments such as high altitude and space; in the field of structural health monitoring, micro-strain and vibration sensors monitor equipment structural deformation and fatigue status in real time, warning of structural failure risks; in the field of infrared detection, modified silicon-based infrared sensors achieve target detection, night vision imaging, and thermal radiation monitoring, supporting the intelligent and precise operation of high-end equipment.
Environmental Monitoring: Empowering Refined Ecological Governance
Semiconductor sensitive materials are the core technical support for refined monitoring and scientific governance of the ecological environment. They can achieve real-time grid monitoring of omnidimensional parameters such as atmosphere, water quality, soil, and radiation, providing data support for precise pollution control, ecological protection, and meteorological warning.
In the field of atmospheric monitoring, gas-sensitive and photoelectric sensors detect formaldehyde, VOC, sulfur dioxide, nitrogen oxides, and dust particle concentrations in real time, achieving real-time monitoring of urban air quality and industrial exhaust gas emissions; in the field of water quality monitoring, ion and humidity sensors detect water pH value, heavy metals, ammonia nitrogen, and residual chlorine parameters, protecting drinking water safety and watershed ecology; in the field of soil monitoring, temperature, humidity, and ion sensors monitor soil water and fertilizer, ions, and pH, assisting in precise planting in modern agriculture; in the field of special environment monitoring, radiation and ultraviolet sensors achieve environmental radiation dose monitoring, preventing radiation safety risks, and comprehensively supporting the refined and digital governance of the ecological environment.
VI. Current Core Shortcomings, Defects, and Limitations of Materials and Devices
Domestic mid-to-low-end semiconductor sensing products have basically achieved localization, and basic independent controllability has been achieved in civilian and general industrial scenarios. However, there are still obvious shortcomings in the fields of high-end materials, precision processes, high-precision devices, and intelligent integration. The overall industrial pattern presents "large but not strong, comprehensive but not refined, overcapacity at the low end, and shortage at the high end." The current industrial bottlenecks are mainly divided into two dimensions: intrinsic material defects and device application shortcomings, which are the core obstacles restricting the high-end breakthrough and localized development of China's sensing industry.
Intrinsic Material Defects
1. Limited Optical Sensing Boundary and Lack of Mid-to-Far Infrared Sensing Capability
Silicon belongs to indirect bandgap semiconductor materials. The electron transition light-emitting efficiency is extremely low, and it almost has no active light-emitting capability, making it unable to be applied to active light-emitting, laser emission, and optical communication light source scenarios; at the same time, the natural optical response band of silicon materials is limited to the visible light range, with no absorption or response to mid-to-far infrared light above 1.1μm. It cannot directly achieve mid-to-far infrared thermal radiation detection and infrared imaging, leading to the long-term reliance on imported rare materials such as germanium and indium gallium arsenide in high-end infrared sensing, night vision detection, and high-temperature infrared temperature measurement scenarios, with high costs and low localization rates.
2. Significant Temperature Drift Characteristics and Insufficient High-Temperature Stability
The carrier characteristics of silicon materials are highly sensitive to temperature. They can work stably under normal temperature conditions, but after the temperature rises, the carrier concentration increases exponentially, causing significant shifts in resistivity and sensitivity, and the signal temperature drift problem is prominent. Ordinary silicon-based sensors show obvious performance degradation in high-temperature environments, and data distortion and accuracy failure are prone to occur under working conditions above 80°C. They cannot adapt to the long-term monitoring needs of high-temperature industries, aviation engines, and new energy high-temperature scenarios. There has long been a localization gap in high-temperature high-end sensors.
3. Extremely Strong Substrate Rigidity and No Flexible Adaptation Capability
Pure silicon-based materials are hard in texture, highly brittle, lack stretching and bending capabilities, and have no curved surface attachment characteristics. They belong to typical rigid materials and cannot adapt to flexible scenarios such as flexible wearables, curved surface devices, human skin attachment, and bionic electronic skin. In the rapidly developing emerging tracks such as flexible smart terminals, non-invasive medical patches, and humanoid robot tactile sensing, pure silicon materials cannot be directly applied, restricting the extension and expansion of the silicon-based sensing system to flexible intelligent scenarios.
Device Application Shortcomings
1. Cross-Interference in Multi-Parameter Detection and Limited Multi-Modal Accuracy
When existing silicon-based integrated sensors synchronously detect multiple parameters such as pressure, temperature, humidity, and gas, there is serious cross-coupling interference between different signals. Temperature fluctuations will affect pressure detection accuracy, and humidity changes will interfere with gas-sensitive signals, leading to a significant decrease in multi-modal synchronous detection accuracy. Currently, the industry can only alleviate interference through algorithm compensation and structural zoning, and cannot thoroughly decouple it at the material and mechanism levels, restricting the high-end landing of monolithic multi-parameter integrated sensing chips.
2. Localization Choke Point Gap in High-End Materials and Precision Processes
Most of the products that can achieve independent mass production in China are ordinary silicon wafers and conventional doping processes. However, high-end materials and precision processes such as heavily doped silicon, SOI high-end silicon-based materials, high-precision heterojunction epitaxy, ultra-thin film deposition, and nanoscale micro-nano etching have long relied on imported equipment and technologies. Domestic high-end materials have problems such as high defect rates, poor batch consistency, and insufficient performance stability. The mass production yield rate of precision processes is low, directly leading to the performance of China's high-end aerospace-grade, industrial-grade, and medical-grade sensors lagging behind international giants, and the high-end market has long been monopolized by overseas enterprises.
3. Single Device Function and Insufficient Integration and Intelligence Level
Domestic traditional silicon-based sensors mainly focus on single-modal sensing, and can only detect single physical or chemical parameters. They have single functions and serious homogenization; most devices can only output raw analog signals, without built-in signal processing, intelligent calibration, and fault self-diagnosis functions. They rely on external circuits and algorithm assistance, with large overall size, high power consumption, low integration, and insufficient intelligence. They cannot adapt to the new generation of smart terminals and humanoid robot scenarios that are miniaturized, multi-functional, and intelligent, and there is a generational gap with international high-end intelligent sensing chips.
VII. Frontier Innovation and Future Technology Development Trends
Currently, international silicon-based semiconductor sensors are in a transition period of extreme excavation of pure silicon + iteration of new materials + multi-parameter fusion + intelligent upgrade; domestically, it is shifting from "large-scale mass production" to "high-end breakthrough, intelligent integration, and iteration of new materials," and achieving low-cost performance upgrades, quickly making up for shortcomings, and breaking through process bottlenecks, reshaping the new stage of the industrial pattern.
Ultimate Performance Breakthrough of Pure Silicon Materials (Without Composite Doping, Excavating Intrinsic Potential)
The extreme excavation of pure silicon materials is the most realistic, most cost-effective, and easiest to land breakthrough path in the short term. It does not require reconstructing production lines or replacing material systems. Relying on process optimization and structural innovation, it can break through the traditional performance limit and quickly narrow the gap with international high-end products.
1. Silicon-Based Surface Plasmon Enhancement Technology, Breaking Through the Limitation of Deep Ultraviolet Sensing
By preparing nanoscale plasmonic metal microstructures on the silicon surface and utilizing the surface plasmon resonance effect, the absorption and response capability of silicon materials to deep ultraviolet band light is greatly enhanced, breaking the shortcoming that traditional silicon materials cannot sense deep ultraviolet light, and achieving ultra-high sensitivity detection in the deep ultraviolet. This technology can be applied to scenarios such as water quality pollutant detection, environmental ozone monitoring, semiconductor wafer defect detection, and ultraviolet sterilization monitoring. It does not need to rely on rare ultraviolet sensing materials, greatly reducing the cost of high-end ultraviolet sensors and improving the localization rate.
2. Heavily Doped Silicon Technology, Expanding the Mid-to-Far Infrared Sensing Boundary
Adopting laser heavy doping and high-energy ion implantation technology to achieve ultra-high concentration precise doping of silicon materials, breaking the 1.1μm infrared absorption limit of silicon, expanding the silicon-based optical response band to the mid-to-far infrared range, and enabling pure silicon materials to have infrared thermal radiation sensing, infrared imaging, and high-temperature infrared temperature measurement capabilities. This technology can replace expensive germanium and indium gallium arsenide materials, greatly reducing the mass production cost of high-end infrared sensors, making up for the shortcomings of China's infrared sensing industry, and adapting to high-end scenarios such as industrial high-temperature detection, aviation infrared detection, and medical precise temperature measurement.
3. Silicon-Based Single-Photon Sensitive Technology, Achieving Ultimate High-Precision Optical Sensing
Through extreme optimization of micro-nano structures and surface passivation enhancement technology, the silicon-based carrier transmission path is optimized to prepare single-photon-level silicon-based optical detectors, which can capture ultra-weak optical signals of single photons, achieving ultimate sensitivity and ultra-high precision in optical sensing. This technology can be applied to frontier scenarios such as quantum communication, laser detection, biological fluorescence detection, and high-end medical optical imaging, promoting the breakthrough of domestic optical sensing towards the ultimate high-precision track and breaking overseas technology monopoly.
Iteration and Upgrade of Material Systems
On the basis of excavating the potential of pure silicon material performance, breaking through the intrinsic physical limits of silicon and laying out a new generation of semiconductor sensitive material systems is the core path for the mid-to-long-term technology leap in the industry from 2026 to 2035. It is also the key layout for the domestic sensing industry to achieve overtaking on the curve, break overseas high-end monopoly, and adapt to future extreme scenarios and emerging intelligent scenarios. Compared with the performance optimization of pure silicon modification, the iteration of a completely new material system belongs to the reconstruction of underlying technology, which can thoroughly solve the core shortcomings of silicon-based materials such as large temperature drift, poor high-temperature resistance, no flexibility, limited optical bands, and weak radiation resistance, building a new sensing capability matrix covering extreme working conditions, flexible sensing, ultra-high precision detection, and ultra-wide spectrum response, and reshaping the high-end sensing industrial pattern. The current industrialization rhythm presents a gradient iteration pattern of "large-scale commercialization of the third generation, small-batch landing of 2D materials, frontier breakthrough of the fourth generation, and forward-looking layout of ultra-wide bandgap."
1. Large-Scale Landing of Third-Generation Wide Bandgap Semiconductors, Making Up for Shortcomings in Extreme Environment Sensing
The third-generation wide bandgap semiconductors, with silicon carbide (SiC) and gallium nitride (GaN) as the core, are currently the new material system with the fastest industrialization progress and highest landing value in the high-end sensing field. They are also the core main force to replace traditional silicon-based materials and seize the extreme working condition sensing market. Compared with silicon materials, wide bandgap materials have core advantages such as ultra-wide bandgap width, ultra-high breakdown field strength, high temperature resistance, radiation resistance, excellent chemical stability, and outstanding high-frequency characteristics, thoroughly breaking through the intrinsic bottlenecks of silicon-based materials such as high-temperature failure above 80°C, easy breakdown under high pressure, and failure under strong radiation interference.
Silicon carbide materials adapt to extreme working conditions such as high temperature, high pressure, strong vibration, and strong corrosion. They can work stably in an ultra-high temperature environment of 600°C, with the signal temperature drift coefficient controlled at the ppm level and no obvious performance degradation. They perfectly adapt to high-end scenarios such as aviation engine working condition monitoring, new energy power battery thermal runaway monitoring, high-temperature metallurgy, oil and gas exploration, and nuclear industry radiation environment detection, solving the pain point that traditional silicon-based sensors cannot adapt to extreme industrial and aerospace military scenarios. Gallium nitride materials focus on the high-frequency and ultraviolet sensing track, possessing excellent ultraviolet spectrum response characteristics and high-frequency signal capture capabilities. They can achieve deep ultraviolet high-precision detection and high-frequency dynamic signal monitoring, and are widely used in fields such as environmental ultraviolet detection, power high-frequency equipment status monitoring, and high-end radio frequency sensing.
Currently, the domestic wide bandgap silicon-based composite sensing process has gradually matured. It can rely on existing MEMS production lines to achieve compatible processing, greatly reducing industrialization landing costs. It is rapidly penetrating from military special scenarios to high-end industrial and new energy civilian scenarios, and is the core breakthrough for the localized development of high-end sensors in the next decade.
2. Acceleration of Industrialization of 2D Semiconductor Materials, Empowering New Tracks in Flexible Intelligent Sensing
2D semiconductor materials represented by graphene, MXene, transition metal dichalcogenides (TMDs), and black phosphorus are the next-generation core substrates adapted to flexible, miniaturized, and ultra-high sensitive sensing. They thoroughly subvert the application boundaries of traditional rigid sensing materials and perfectly match future emerging scenarios such as humanoid robots, flexible wearables, non-invasive medical treatment, and bionic electronic skin. These materials have unique advantages such as atomic-level ultra-thin structure, ultra-large specific surface area, ultra-high carrier mobility, excellent flexible bending characteristics, and multi-mechanism compatible sensing, and are a frontier material system that cannot be replaced by silicon-based materials.
From the perspective of sub-characteristics and applications, graphene has excellent conductive performance and extremely high sensitivity. It can capture ultra-weak mechanical, electrical, and chemical signals, adapting to high-precision pressure sensing, biological weak physiological signal detection, and trace gas detection; MXene materials have strong hydrophilicity and rich surface active sites, with outstanding advantages in humidity, ion, and biological sensing fields. They can achieve high-precision water quality detection and trace parameter monitoring of human body fluids; transition metal dichalcogenides such as molybdenum disulfide have adjustable bandgaps and wide photoelectric response bands, enabling multi-band optical sensing in visible light and near-infrared, making up for the shortcomings of silicon-based optical sensing. At the same time, all 2D materials have good flexible machinability, can achieve arbitrary curved surface attachment, and can be repeatedly bent without failure, thoroughly solving the rigidity and brittleness defects of silicon-based materials.
Currently, 2D semiconductor materials are transitioning from laboratory R&D and small-batch trial production to large-scale commercialization. With the continuous breakthroughs in thin film transfer, large-area film formation, and batch consistency processes, they will be fully landed in scenarios such as flexible smart terminals, smart medical care, and bionic robots in the future, becoming a new growth pole in the sensing industry.
3. Iteration and Optimization of Second-Generation Compound Semiconductors, Deepening Cultivation in the High-End Optoelectronic Sensing Field
The second-generation compound semiconductors, with gallium arsenide (GaAs) and indium phosphide (InP) as the core, have continuously improved process maturity after years of technology iteration. They have irreplaceable value in the fields of high-end optoelectronics and high-frequency sensing, and are an important supplementary material system to make up for the shortcomings of silicon-based mid-to-far infrared sensing and high-frequency sensing. Compared with silicon materials, compound semiconductors have higher electron mobility, wider spectral response bands, and better high-frequency performance. They can achieve stable response in the mid-to-far infrared band above 1.1μm, adapting to scenarios such as high-end infrared imaging, laser detection, optical communication sensing, and high-frequency magnetic field detection.
The core iteration direction of the industry at this stage is the silicon-based heterogeneous integration process. By epitaxially growing compound semiconductor thin films on the silicon substrate, a composite structure of "silicon-based process maturity + high performance of compound materials" is constructed. It not only retains the cost advantages and integration advantages of traditional MEMS mass production but also makes up for the shortcomings of silicon-based optoelectronic sensing. It effectively solves the pain points of high cost and difficulty in large-scale integration of pure compound materials. Currently, small-batch commercial landing has been achieved in the fields of high-end infrared sensing, lidar, and industrial precision optoelectronic detection.
4. Forward-Looking Layout of Fourth-Generation Ultra-Wide Bandgap Materials, Seizing the Future Ultimate Sensing High Ground
The fourth-generation ultra-wide bandgap semiconductor materials, represented by gallium oxide (Ga₂O₃) and aluminum nitride (AlN), are the ultimate performance materials for long-term forward-looking layout in the industry, representing the ultimate iteration direction of sensing materials. These materials have bandgap widths, temperature and pressure resistance, and radiation resistance far exceeding the first three generations of semiconductors. They can adapt to extreme scenarios such as ultra-high temperature, ultra-high pressure, ultra-strong radiation, and ultra-high frequency. They are the core substrates in top fields such as aerospace deep space exploration, nuclear industry, ultra-high voltage power sensing, and extreme environment scientific research monitoring.
Among them, the bandgap width of gallium oxide can reach 4.8eV. It has ultimate ultraviolet detection capability and high-temperature stability, enabling solar-blind ultraviolet high-precision detection without background light interference, adapting to high-end security detection, deep space ultraviolet remote sensing, and power arc fault detection; aluminum nitride has excellent thermal conductivity, insulation, and stability, and can be used in frontier fields such as ultra-high precision thermal sensing and high-frequency piezoelectric sensing. Currently, domestic ultra-wide bandgap materials are still in the stage of laboratory research and process verification, and have not yet achieved large-scale device landing. However, they have become the core layout direction of leading enterprises and scientific research institutions, and will support the technological breakthrough of the high-end ultimate sensing industry after 2030.
Overall, in the future, semiconductor sensitive materials will form a multi-level and differentiated material system with silicon-based materials as the mainstay, modified silicon for upgrade and iteration, wide bandgap for large-scale commercialization, 2D materials for flexible empowerment, and ultra-wide bandgap for forward-looking leadership. It will achieve sensing coverage of all scenarios, all precision, and all working conditions, thoroughly breaking the existing industrial technology bottlenecks, and promoting the comprehensive upgrade of the domestic sensing industry from low-end mass production to high-end independence and frontier leadership.
Intelligent Integrated Upgrade at the Device End (Ultimate Development Direction of the Industry)
Material iteration is the foundation for performance upgrade, and intelligent device integration is the ultimate form of industrial landing. In the next decade, semiconductor sensitive devices will thoroughly get rid of the traditional model of "single sensing, independent devices, external processing," and comprehensively evolve towards single-chip multi-modal sensing, sensing-computing-storage integration, AI intelligent calibration, self-diagnosis and self-healing, and ultra-low power consumption micro-integration, solving the core shortcomings of current domestic devices such as single functions, low integration, insufficient intelligence, and multi-parameter cross-interference.
First, the popularization of multi-modal monolithic integration technology. Relying on heterojunction epitaxy, micro-nano zoning processing, and signal decoupling processes, it is realized to integrate multi-dimensional sensitive units of pressure, temperature, humidity, photoelectric, and gas on a single silicon-based chip, equipped with built-in hardware decoupling structures, solving the multi-parameter cross-interference problem from the physical level, achieving multi-parameter synchronous high-precision detection, replacing the traditional multi-device combination scheme, greatly reducing terminal size, power consumption, and assembly costs, and adapting to lightweight scenarios such as drones, humanoid robots, and micro smart terminals.
Second, the large-scale landing of sensing-storage-computing integrated chips. Breaking the traditional architecture of separating sensing, computing, and storage, monolithically integrating sensitive material units, signal processing circuits, AI computing power units, and storage modules, realizing the integration of raw signal acquisition, real-time algorithm calibration, data computing, local storage, and intelligent output, without relying on external main control chips, greatly improving response speed and system stability, reducing equipment energy consumption, and adapting to IoT terminals, wireless sensor networks, and edge intelligent monitoring scenarios.
Third, the iteration of intelligent self-healing and self-adaptive technology. Through material modification and circuit architecture optimization, combined with embedded AI algorithms, device temperature drift self-calibration, error self-adaptive correction, fault self-diagnosis, and performance degradation self-compensation are realized, thoroughly solving the pain points of traditional sensors such as accuracy degradation after long-term use and poor environmental adaptability, greatly improving device service life and batch consistency, and narrowing the stability gap with international high-end devices.
Fourth, innovation in flexible integration and system packaging. Combining 2D semiconductor flexible materials and advanced Chiplet packaging technology, heterogeneous integration of rigid high-precision sensing units and flexible adaptive structures is realized, taking into account detection accuracy and curved surface attachment capabilities, adapting to new scenarios such as human wearables, bionic skin, and curved surface equipment, and building a new generation of intelligent sensing system integrating rigidity and flexibility.
In summary, from 2026 to 2035, the semiconductor sensitive materials and devices industry will form a three-dimensional upgrade path of extreme material excavation + new system iteration + device intelligent integration, completing the industrial leap from "material following, device OEM, low-end mass production" to "material originality, device leadership, high-end monopoly," and comprehensively achieving the localized high-end breakthrough of the semiconductor sensing industry.
Conclusion
This article systematically reviews the category characteristics, core mechanisms, process routes, performance indicators, and all-scenario application ecology of semiconductor sensitive materials, and completely explains the underlying technical logic of silicon-based semiconductors as the core substrate for intelligent sensing. With the unique endowments of strong modifiability, multi-mechanism compatibility, easy micro-nano integration, and easy reading of electrical signals, silicon-based semiconductor sensitive materials rely on seven mature commercial sensitive mechanisms and standardized MEMS processing systems to build omnidimensional sensing capabilities in mechanics, thermodynamics, optics, magnetism, chemistry, and biology. They are the irreplaceable core cornerstone of the modern sensor industry, comprehensively supporting the intelligent iteration and upgrade in fields such as consumer electronics, industrial intelligent manufacturing, high-end equipment, smart medical care, and ecological monitoring.
Facing the future, the semiconductor sensitive materials industry will continue to break through following the three core development paths of extreme excavation of pure silicon materials, iteration of new material systems, and intelligent upgrade of device integration. By deeply excavating the potential of silicon intrinsic performance, laying out frontier materials such as wide bandgap and 2D semiconductors, and promoting the landing of monolithic multi-modal integration and AI adaptive sensing technology, it will gradually break through traditional technical shackles, make up for industrial shortcomings, and overcome key process barriers. It will realize the upgrade from single-point detection to multi-modal intelligent sensing and the leapfrog iteration of process technology, providing solid and lasting underlying technical support for the silicon-based sensing industry to comprehensively move towards a higher level and industrial innovation and development.
Author | Guo Yuansheng, Deputy Director of the Science and Technology Committee of the Jiusan Society Central Committee and Executive Vice Chairman of the China Sensor and IoT Industry Alliance
Editor | Yang Pengyue, Art Editor | Maria, Supervisor | Zhao Chen