Development of World’s Smoothest Silicon Carbide Epitaxial Wafer Surface by SDK
Showa Denko made an announcement on development of highly smooth (0.4nm in roughness) surface for its largest size four-inch silicon carbide (SiC) epitaxial wafers. The wafers are made by forming a thin layer of single-crystal SiC on the surface of SiC bulk wafers. This new development is a significant improvement in surface roughness in comparison to the SiC epitaxial wafers that come with the roughness of 1 to 2.5 nm, world’s highest level at 0.4 nm. The target application for SiC epitaxial wafers would be in power devices such as inverters responsible for controlling rotation of motors in automobiles, train and industrial/home electric appliances, where the SiC epitaxial wafers will outperform the currently used silicon based semiconductor. In making of SiC based inverters, Schottky barrier diod (SBD) and metal semiconductor field-effect transistor (MOSFET) should be used. While SiC-SBD is already available in the market, SiC-MOSFET development is still underway to fulfill it requirement for high surface smoothness as it uses oxide film formed on the surface of epitaxial wafers in device operation. Highly uneven surface in conventional SiC epitaxial wafers make it difficult to obtain a high quality oxide film, making the new development a great contributor to the early development of SiC-MOSFET as well as next generation inverters. The SiC power devices for the next generation inverters are capable of operating at a high temperatures and under high-voltage heavy current making them suitable for production of small and light-weight power control parts for automobiles, industrial/home electric appliances. At the same time the new device will contribute in reduction of energy loss in process of power control, conserving energy and restricting heat generation in parts. The SiC inverters are expected to be used in electric vehicles and hybrid cars.
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