Introduction

The widespread adoption of new energy vehicles, grid integration of renewable energy, and comprehensive upgrading of advanced industrial intelligent manufacturing have driven the power semiconductor industry to transition from the silicon era to the wide band gap era. As a core wide band gap material, silicon carbide (SiC) features superior physical properties and has become the preferred material for high-voltage, high-frequency, and high-efficiency power devices.
In the entire SiC device industrial chain, SiC substrates serve as the most fundamental core carrier. Critical device parameters, including breakdown voltage, conduction loss, thermal stability, and service life, are directly determined by the crystal quality, defect density, flatness, and electrical properties of SiC substrates.
Compared with subsequent processes such as epitaxy, etching, oxidation, and packaging, native defects in substrates are irreversible and transmit throughout the entire manufacturing chain, acting as a core bottleneck restricting the yield, reliability, and large-scale cost reduction of SiC devices. Based on the latest 2025 SiC technical review published in Materials, this article comprehensively analyzes the core industrial value and inevitable development trend of SiC substrates from four dimensions: intrinsic material advantages, core market drivers, industrial competition landscape, and technical iteration logic.

 

1. Intrinsic Advantages of SiC Materials: Substrates Determine the Upper Limit of Device Performance

Traditional silicon (Si) power semiconductors have approached their performance limits in high-voltage, high-temperature, high-frequency, and high-efficiency scenarios due to inherent material constraints. Commercially dominant 4H‑SiC substrates deliver overwhelming material superiority, providing sufficient room for performance upgrading of advanced power devices. The core parameter comparisons are as follows:

• Maximum breakdown electric field: 10 times that of silicon, enabling the design of higher-voltage devices and significantly reducing chip size;

• Electron saturation drift velocity: 2 times that of silicon, suitable for high-frequency switching applications to meet the demands of 5G communication and high-frequency inverter equipment;

• Band gap: 3 times that of silicon, offering superior high-temperature resistance and radiation resistance, enabling stable long-term operation at junction temperatures above 200°C;

• Thermal conductivity: 3 times that of silicon, greatly improving heat dissipation efficiency, simplifying equipment heat dissipation structures, and reducing overall power consumption and device volume.

Benefiting from the above advantages, SiC MOSFETs fabricated on high-quality SiC substrates feature ultra-low switching loss, fast response speed, and excellent structural stability. Under the same breakdown voltage specifications, SiC chips are much smaller than silicon-based chips, enabling miniaturization, lightweight design, and high energy efficiency of power electronic equipment.
In comparison with gallium nitride (GaN), another wide band gap semiconductor material, GaN devices are more suitable for low-to-medium voltage and high-frequency consumer electronics scenarios. In contrast, SiC substrates support higher voltage and higher power operating conditions, making them the optimal solution for 800V high-voltage electric vehicle platforms, rail transit, large-scale photovoltaic energy storage, and industrial high-voltage equipment. The performance advantages of all SiC devices rely on zero-defect, highly uniform single-crystal SiC substrates.

 

2. Market Boom: New Energy Vehicles as the Core Growth Driver for SiC Substrates

The global implementation of dual-carbon policies and stringent automotive carbon emission regulations have accelerated the iterative upgrading of the new energy vehicle industry, directly triggering explosive market demand for SiC devices and upstream SiC substrates. In 2017, Tesla took the lead in large-scale adoption of SiC MOSFETs in main vehicle inverters, officially launching the commercialization of SiC materials in the automotive sector.
Currently, automotive applications account for 63% to 80% of the global SiC market, becoming the killer application for SiC technology. Almost all mainstream automakers and automotive Tier 1 suppliers have completed technical layout and mass production deployment of SiC devices. In addition to vehicle main inverters, SiC penetration is rapidly increasing in on-board chargers, high-voltage fast charging piles, photovoltaic inverters, industrial motor drives, and rail transit traction systems. The industry forecasts that the SiC-related application market will maintain a double-digit compound annual growth rate from 2019 to 2027.
Industry authoritative data predicts that by 2050, the global market demand for SiC wafers will be equivalent to the current 300mm silicon wafer production capacity of the world’s largest wafer foundries. The exponentially growing downstream demand contrasts sharply with the industry’s current situation of insufficient substrate production capacity and extremely difficult preparation processes. The production capacity and quality of SiC substrates have become the core bottleneck restricting the development of the entire SiC industry.

 

3. Industrial Landscape: Vertical Integration and Wafer Size Iteration Intensify Substrate Track Competition

Driven by booming downstream demand, the global landscape of SiC substrates and devices has undergone disruptive changes, forming two core development trends:

 

3.1 Full Industrial Chain Vertical Integration Becomes Mainstream

Wolfspeed remains the core global supplier of high-end SiC substrates. To avoid supply shortages and price fluctuations in the substrate supply chain, leading international power device manufacturers including STMicroelectronics, Infineon, ROHM, and Onsemi have actively expanded upstream layouts. They have built vertical IDM production systems covering SiC substrates – epitaxial wafers – device design – module packaging, ensuring mass production stability and cost advantages through independent control of substrate production capacity.

 

3.2 Large-size Wafer Iteration Accelerates Cost Reduction

The industry is accelerating the upgrade from 150mm (6-inch) to 200mm (8-inch) SiC wafers. Larger-sized wafers can produce more chips per batch, significantly reducing the manufacturing cost of single devices and serving as the core path for large-scale cost reduction in the SiC industry. However, large-size SiC single crystal growth faces severe challenges including high thermal stress, difficult defect control, and stringent flatness requirements, which have become the key research priorities of global leading enterprises.

4. Yield Core Logic: Substrate Defects Determine the Upper Limit of the Entire Process Chain

The complete manufacturing process of SiC devices follows the sequence: SiC single crystal substrate preparation → epitaxial layer growth → ion implantation doping → dry etching shaping → thermal oxidation gate dielectric fabrication → metal contact process → device packaging and testing. Different from mature silicon-based processes, SiC manufacturing has extremely low fault tolerance. Native defects in substrates, such as micropipes, dislocations, and stacking faults, propagate layer by layer to epitaxial layers and device channels, ultimately causing device leakage, premature breakdown, increased dynamic loss, and long-term reliability failure.
Silicon-based processes can compensate for partial substrate defects through subsequent annealing and passivation treatments. Nevertheless, SiC features extremely high chemical bond energy, making native substrate defects irreversible and unrepairable via post-processing technologies. This is the fundamental reason for the high price of SiC substrates and the difficulty in rapidly improving the yield of automotive-grade SiC devices. The large-scale commercial replacement of silicon-based devices by SiC devices fundamentally relies on breakthroughs in the mass production technology of high-quality, low-defect, large-size, and low-cost SiC substrates.

Conclusion

SiC substrates are the foundation of the entire wide band gap power semiconductor industry. Their technical level, production capacity scale, and quality stability directly determine the development ceiling of the SiC industry. The explosive demand of the new energy market has fully exposed the shortcomings of substrate production capacity. In the future, core industrial competition will focus on the preparation technology and large-scale production capacity of low-defect and large-size SiC substrates.
 

JXT professionally supplies 2–12 inch full-specification silicon carbide substrates, supporting customized and batch supply of high-uniformity, low-defect substrates, and catering to various high-end application scenarios such as new energy vehicles, photovoltaic energy storage, and industrial high-voltage power devices.