Driven by the rapid rise of electric vehicles, renewable energy systems, and next-generation communication technologies, the silicon carbide (SiC) substrate industry has entered a period of accelerated expansion. As a core material in wide-bandgap semiconductors, SiC enables high-temperature, high-voltage, and high-frequency device performance beyond the limits of traditional silicon. With production capacity scaling up, the market is moving toward broader adoption, lower costs, and continuous technology enhancement.
1. Overview of Silicon Carbide Substrates
1.1 Properties of Silicon Carbide
Silicon carbide (SiC) is a synthetic compound composed of silicon and carbon. It features a very high melting point (~2700°C), a hardness second only to diamond, high thermal conductivity, a wide bandgap, a high breakdown electric field, and fast electron saturation drift velocity. These characteristics make SiC one of the most important materials for power electronics and RF applications.
1.2 Types of SiC Substrates
SiC substrates are categorized by electrical resistivity:
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Semi-insulating substrates (≥10⁵ Ω·cm), used for GaN-on-SiC RF devices in 5G communication, radar, and high-frequency electronics.
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Conductive substrates (15–30 mΩ·cm), used for SiC epitaxial wafers in power devices for EVs, renewable energy, industrial modules, and rail transit.
2. SiC Material Industry Chain
The SiC value chain consists of raw material synthesis, crystal growth, ingot machining, wafer slicing, grinding, polishing, epitaxial growth, device fabrication, and downstream applications. Among these steps, substrate manufacturing has the highest technical barriers and cost contribution, accounting for roughly 46% of the total device cost.
Semi-insulating substrates support high-frequency RF applications, while conductive substrates serve high-power and high-voltage device markets.
3. SiC Substrate Manufacturing Process
SiC substrate production requires dozens of high-precision steps to control defects, purity, and uniformity.
3.1 Raw Material Synthesis
High-purity silicon and carbon powders are mixed and reacted at temperatures above 2000°C to form SiC powder with controlled crystal phases and impurity levels.
3.2 Crystal Growth
Crystal growth is the most critical step affecting substrate quality. Main methods include:
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PVT (Physical Vapor Transport): The mainstream industrial method where SiC powder sublimates and recrystallizes on a seed crystal.
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HTCVD (High-Temperature CVD): Enables higher purity and lower defect levels but requires more complex equipment.
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LPE (Liquid Phase Epitaxy): Capable of producing low-defect crystals but higher in cost and more complex to scale.
3.3 Ingot Processing
The grown crystal is oriented, shaped, and ground into standardized ingots.
3.4 Wafering
Diamond wire saws cut the ingot into wafers, which undergo warp, bow, and TTV inspection.
3.5 Grinding and Polishing
Mechanical and chemical processes thin the surface, remove damage, and achieve nanometer-level flatness.
3.6 Final Cleaning
Ultra-clean procedures remove particles, metal ions, and organic contaminants, producing the final SiC substrate.
4. Global Market Outlook
Industry research indicates that the global SiC substrate market reached approximately USD 754 million in 2022, representing 27.8% growth year-over-year. The market is expected to reach USD 1.6 billion by 2025.
Conductive substrates account for around 68% of demand, driven by EVs and renewable energy. Semi-insulating substrates represent about 32%, driven by 5G and high-frequency applications.
5. Competitive Landscape
The industry has high technical thresholds, including long R&D cycles, crystal defect control, and advanced equipment requirements. While global suppliers currently hold strong positions in conductive substrates, domestic manufacturers are rapidly improving crystal growth quality, defect density control, and large-diameter capabilities. Cost competitiveness will increasingly depend on yield improvement and production scale.
6. Future Development Trends
6.1 Larger Substrate Diameters
Transitioning to large-diameter wafers is essential for reducing cost per device and boosting output.
6.2 Lower Defect Density
Reducing micropipes, basal plane dislocations, and stacking faults is key to achieving high-yield device manufacturing.
6.3 Cost Reduction Through Scale
As more manufacturers reach industrial-scale production, cost advantages and supply stability will accelerate global adoption of SiC devices.
6.4 Demand Driven by Electrification and High-Power Systems
Strong growth momentum comes from electric vehicles, fast-charging infrastructure, photovoltaics, energy storage systems, industrial power modules, and advanced communication systems.
Conclusion
The silicon carbide substrate industry is entering a strategic window of growth characterized by expanding applications, rapid technology progress, and increasing production scale. As wafer sizes increase and crystal quality improves, SiC will play an increasingly important role in global electrification and power conversion systems. Manufacturers who lead in defect control, yield optimization, and large-diameter technology will seize the next phase of market opportunity.
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