Recently, the industrialization process of 12-inch silicon carbide (SiC) has been accelerating globally. Its application scenarios are steadily expanding, including emerging hot fields such as power semiconductors, optical waveguides for AR glasses, and advanced packaging for AI chips, demonstrating immense development potential.
However, the cost of 12-inch SiC remains one of the key bottlenecks restricting its large-scale popularization. According to research by Ascompounds, the current market price for a single 12-inch SiC substrate is as high as tens of thousands of CNY, leaving significant room for price reduction to reach a reasonable level for commercialization at scale.
Against this backdrop, the entire industry is adopting various technologies to reduce the cost of 12-inch SiC. Recently, two companies in China and Japan have achieved new breakthroughs in SiC substrate bonding and polycrystalline SiC technologies, respectively, which are expected to resolve the high-price dilemma of 12-inch SiC.
Sumitomo Metal Mining: 12-Inch Bonded SiC Delivered
On September 18, Sumitomo Metal Mining (SMM) officially announced that it has achieved a breakthrough in 12-inch SiC technology.
According to SMM's official website, its subsidiary SICOXS has "successfully developed the world's first 12-inch bonded SiC substrate" and has already delivered 12-inch bonded SiC samples to SiC semiconductor customers.
This customer is likely Japan's Shindengen Electric Manufacturing. As early as December 2025, Shindengen Electric Manufacturing announced the adoption of SMM's bonded SiC substrates for the development of SiC MOSFET devices, and has already provided SiC MOSFET samples externally.
Sumitomo Metal Mining (SMM) is a large-scale comprehensive materials enterprise in Japan, with its business covering three major sectors: resources, smelting, and materials. Its operating revenue for the fiscal year 2025 was approximately CNY 76.7 billion. In the SiC field, in 2017, SMM began to layout low-cost composite/bonded SiC substrates by acquiring SICOXS from Kaga Electronics.
SMM is responsible for the single-crystal SiC and polycrystalline SiC materials required for bonding, while SICOXS is mainly responsible for the development, manufacturing, and sales of SiC bonded substrates. SICOXS has completed the mass production of 6-inch products and the layout of 8-inch production lines, with a capacity that will exceed 10,000 pieces per month.
Titan Future: Breakthrough in 12-Inch Polycrystalline SiC Substrate
SiC bonded substrate technology generally consists of two parts: a single-crystal functional layer and a base layer. There are multiple choices for the base layer, including polycrystalline SiC (Poly-SiC), 3C-SiC, and 4H-SiC D-grade wafers. Recently, domestic manufacturers have achieved a technological breakthrough in 12-inch polycrystalline SiC.
On September 7, Titan Future announced that it has recently launched "China's first 12-inch large-size polycrystalline SiC substrate."
According to the introduction, Titan Future has previously achieved the localization of 6-inch and 8-inch Poly-SiC substrates. The newly released 12-inch polycrystalline SiC product has been optimized in terms of high-temperature stability, structural uniformity, and service life, making it suitable for high-end applications such as heat dissipation substrates for AI advanced packaging, SiC epitaxial substrates, crystal growth carrier plates, and heat dissipation in high-temperature processes.
Shenzhen Titan Future, founded in 2021, is an enterprise relying on Central South University and focusing on high-performance carbon-based and ceramic-based composite new materials. Its main products include SiC, tantalum carbide (TaC) coated graphite parts, pedestals for crystal growth/epitaxy, and polycrystalline SiC composite substrates. In 2025, the South China headquarters project of Titan Future was signed and settled in Xiamen, where a full-chain capacity of 500,000 composite SiC substrates will be built.
Layout of Bonded SiC by Leading Enterprises: Outstanding Cost Reduction Potential of 12-Inch Bonded Substrates
In fact, the technological route of bonded SiC substrates has previously attracted significant attention. According to Ascompounds, they have over 35 potential customers, and six customers, including STMicroelectronics, X-FAB, Clas-SiC, Diodes, and Resonac, have previously certified related products.
According to research by Ascompounds, domestic SiC device manufacturers are also laying out this technological route, and some have already completed product certification. For example, in the SiC epitaxy segment, in January 2026, Tianyu Semiconductor and Qinghe Jingyuan signed a strategic cooperation agreement to jointly promote the process development and technological iteration of bonding materials such as 8-inch single-crystal/polycrystalline SiC bonded substrates and 12-inch and above SiC composite heat dissipation substrates.
From the delivery of 12-inch polycrystalline SiC substrates by SMM, to the breakthrough in small-batch orders for 12-inch SiC epitaxy by Hantian Tiancheng, to the development of 12-inch SiC substrates by Resonac, based on these advancements, it is reasonable to speculate that leading SiC device companies are advancing the R&D of 12-inch bonding technology.
Bonding technology can significantly reduce the consumption of single-crystal SiC substrates. According to SMM's analysis, by bonding a thin layer of high-quality single-crystal SiC onto a low-resistance polycrystalline SiC support substrate, the thickness of the single-crystal substrate can be reduced to less than 1 micrometer. Originally, a 350μm single-crystal SiC wafer can be used to manufacture more than 50 bonded substrates.
However, since the price drop of 6-inch and 8-inch SiC substrates has exceeded expectations, the commercialization steps for SiC bonded substrates by manufacturers such as Soitec have slowed down. So, in terms of 12-inch SiC, can the advantages of this technology be highlighted? We will wait and see.
This article is published by Ascompounds, focusing on industry observations of third-generation semiconductors (SiC and GaN).