Development of an ultra-smooth surface formation technique required for highly efficient SiC power device fabrication.

碳化硅（SiC）具有良好的导热性、良好的载流子迁移率和较高的化学稳定性，是一种很有前途的用于高温、高频和大功率器件的下一代半导体材料。然而，SiC衬底由于其机械硬度和明显的化学惰性而相对难以加工。本研究的目的是开发新一代半导体器件生产中不可或缺的高精度、高效率的SiC衬底平面化方法。在这项研究中，我们提出了一种利用Fe催化剂和H2O2溶液产生的OH自由基对SiC表面和GaN表面进行平整化的新方法，并证明了该方法的有效性和影响。最后，我们成功地平化了整个2英寸SiC衬底，并成功地平滑了GaN表面。

Silicon carbide (SiC) is a promising next-generation semiconductor material for high-temperature, high-frequency and high-power device applications due to its excellent properties, such as good thermal conductivity, good carrier mobility and high chemical stability. However, SiC substrates are relatively difficult to machine because of their mechanical hardness and marked chemical inertness.The purpose of this research is to develop the high precision and high efficiency planarization method for SiC substrate indispensable to production of a next-generation semiconductor device. In this study, we have proposed a novel planarization method for a SiC surface and GaN surface utilizing the OH radicals generated from an Fe catalyst and H2O2 solution, and demonstrated the effectiveness and impact of the proposed method. Finally, we have succeeded in planarizing overall 2-inch SiC substrate and succeeded in smoothing GaN surface.