[News] Chinese Researchers Produced SiC Epitaxial Film over 300μm in Thickness
Researchers at the Advanced Semiconductor Institute of the Hangzhou International Innovation Center at Zhejiang University recently announced a major breakthrough. A team led by Professor Xiaodong Pi and Researcher Rong Wang successfully fabricated an ultra-thick silicon carbide (SiC) epitaxial film exceeding 300μm in thickness. The achievement marks the first stable preparation of SiC epitaxial films at this thickness level internationally, establishing a critical materials foundation for the development of 30kV-class ultra-high-voltage power devices.
As a core wide bandgap semiconductor material, SiC offers advantages including high breakdown electric field strength and superior thermal conductivity, enabling broad adoption in applications such as electric vehicles and photovoltaic systems. Current mainstream SiC devices typically support voltage ratings below 3.3kV, requiring epitaxial layers of only around 30μm. While the required thickness increases by more than tenfold, the complexity of crystal growth rises exponentially.
To address technical challenges associated with stress accumulation and defect control during thick-film epitaxy, the research team carried out systematic optimization across equipment design, process iteration, and defect engineering. The team developed a complete ultra-thick epitaxial growth and defect management process. The resulting epitaxial wafer reached a thickness of 312μm while maintaining a critical surface defect density as low as 0.75/cm². Researchers also introduced an ultraviolet-assisted high-temperature post-processing technology capable of eliminating 100% of fatal “Shockley-type stacking faults,” resolving a key reliability issue for ultra-thick films.
According to Researcher Rong Wang, ultra-thick epitaxial films serve as the “voltage-bearing backbone” of high-voltage devices, and the breakthrough is expected to directly support the development of 30kV-class SiC power devices. Such devices could enable applications in high-voltage transmission for smart grids, high-efficiency railway power systems, and electric propulsion systems for large vessels, helping reduce system costs, improve efficiency, and shrink equipment size while strengthening China’s position in next-generation ultra-wide-bandgap semiconductor technologies.
The team noted that the technology has already undergone multiple rounds of stability verification and demonstrates commercialization potential. Moving forward, researchers plan to advance pilot-scale validation and further process iterations to accelerate large-scale deployment of ultra-thick SiC epitaxial materials for next-generation energy and high-voltage power applications.
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