Every electric-car inverter and every AI data-center power supply quietly depends on a material most people never see. Silicon carbide (碳化硅) is that material — and the global ranking at its foundation just flipped.
For years the top of the silicon carbide (SiC) substrate market was held by Wolfspeed, a U.S. pioneer. According to a March 2026 report by Japanese research firm Fuji Keizai (富士经济), a Shandong-based company called SICC (天岳先进, 688234.SH) took the global No.1 position in 2025 with a 27.6% share of conductive SiC substrates. Three years earlier SICC's share was around 12%.
That is not a rounding error. It is a sign that the most valuable part of the wide-bandgap supply chain — the crystal wafer that everything else is built on — is consolidating faster than expected in China.
Why a "substrate" matters at all
A substrate is the starting slice of crystal. Before any chip is designed or any device is packaged, someone has to grow a flawless cylinder of silicon carbide and slice it into thin wafers. This step sets the ceiling for yield, cost, and performance of every downstream device — and it has historically been the hardest, most capital-intensive part of the SiC chain.
Silicon carbide matters because it handles far higher voltages and temperatures than ordinary silicon with much lower energy loss. That is why it shows up in:
- EV main-drive inverters, where it shrinks the power module and extends range.
- Fast chargers and solar inverters, where efficiency directly cuts heat and cost.
- Data-center power supplies, where GaN and SiC together are reducing the energy burned converting grid power to the voltages GPUs need.
- Rail, grid equipment, and even AR-waveguide optics, where SiC's hardness and thermal properties help.
The wedge was 8-inch wafers
The change came down to wafer size. Like the silicon industry before it, SiC is migrating from 6-inch to 8-inch wafers. SICC's share of the 8-inch segment hit 51.3% in 2025, and its 6-inch share reached 27.5% — both firsts for a Chinese supplier, per Fuji Keizai.
The economic logic is simple. SICC cites its own figures that an 8-inch wafer yields about 90% more chips than a 6-inch wafer and can cut per-chip cost by roughly 54%. When the industry switches sizes, the supplier that is already shipping the larger wafer in volume captures share quickly. SICC says it was the first to mass-produce 12-inch conductive SiC substrates, announced in 2024, and is now making volume deliveries of 12-inch product to key customers.
Who actually buys from SICC
Substrates are a trust business. A device maker qualifies a wafer supplier through months of testing of epitaxy, device fabrication, and packaging, then rarely switches. SICC says it works with more than half of the world's top ten power-semiconductor manufacturers, naming Infineon and Bosch among them, and received Bosch's Excellence Supplier Award in 2025.
Scale is part of the story. SICC announced a capacity plan of about 960,000 wafers per year in 2024 and is executing it in phases. In August 2025 it added an H-share listing in Hong Kong, becoming the only SiC substrate maker with both A-share and H-share listings — a structure that gives it a wider funding base for capacity expansion.
What this means beyond the scoreboard
A substrate lead does not equal dominance of the whole SiC industry. The valuable device and module layer — where Infineon, STMicroelectronics, onsemi, and Wolfspeed design and sell finished power components — is still largely Western-controlled. Substrate share is a foundation, not a finish line.
But foundations set the terms of competition. When the cheapest, largest, most consistent wafers come from one supplier, device makers around the world — including Western ones — have a reason to qualify that supply chain. That is why a quiet Shandong materials company now sits in the critical path of the global energy-transition hardware build-out.
What readers can do now
- When comparing EVs or chargers, look for "SiC" in the power electronics spec. It is a real efficiency signal, not marketing fluff, and is moving from premium option to standard fitment.
- Distinguish substrate from device makers if you follow the sector. A substrate leader (like SICC) and a device leader (like Infineon or ST) sit in different, only partly overlapping businesses; their fortunes diverge.
- Watch the 8-inch migration as a cost clock. Each step up in wafer size is what historically pulls SiC device prices down and opens new mass-market uses.
Honest limitations
This article relies heavily on a single market-research source (Fuji Keizai, via SICC's own disclosures) for the share figures, and on company-reported capacity and cost numbers that are not independently audited. "Substrate share" measures one layer of a long chain and says little about device-design or packaging leadership. Export-control dynamics, pricing pressure from overcapacity, and the pace of Western 8-inch ramp-up are not covered here. The 2025 ranking is a point-in-time snapshot in a fast-moving industry.
Key takeaways
- SICC (天岳先进) became the world's No.1 SiC substrate supplier in 2025 with a 27.6% share, surpassing Wolfspeed, per Fuji Keizai.
- The lead came from 8-inch wafers, where SICC holds over 50% share and cites ~90% more chips and ~54% lower per-chip cost versus 6-inch.
- A substrate lead is foundational, not total: Western firms still dominate SiC device and module design, so the shift reshapes the supply chain without ending competition.