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

碳化硅具有导热性能好、载流子迁移率好、化学稳定性高等优点，是一种非常有前途的高温、高频、大功率半导体材料。然而，由于碳化硅衬底的机械硬度和明显的化学惰性，使得其加工相对困难，本研究的目的是开发下一代半导体器件生产所必需的高精度、高效率的碳化硅衬底平坦化方法。在这项研究中，我们提出了一种利用Fe催化剂和H_2O_2溶液中产生的OH自由基对碳化硅表面和氮化镓表面进行平坦化的新方法，并验证了该方法的有效性和影响。最后，我们成功地平坦化了整个2英寸的碳化硅衬底，并成功地实现了GaN表面的平整。

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.