SBIR Phase I: Gentle Atomic Level Chemical Mechanical Smoothening (CMS) of GaN and SiC Substrates

这项小型企业创新研究(SBIR)第一阶段研究项目将为GaN和碳化硅基宽禁带材料开发一种新的温和原子尺度表面抛光方法。该工艺基于化学机械抛光(CMS)技术，该技术是Sinmat开发的用于抛光硬质氮化物和硬质合金材料的新型化学机械抛光(CMP)工艺的独特子集。在这一过程中，浆料中的化学物质发生反应，形成一层很薄的钝化层(通常是软氧化层)，很容易被纳米颗粒去除。抛光的质量将取决于材料的表征和薄膜生长技术。通常，传统的机械抛光或化学机械抛光使用大的(100 Nm)硬颗粒(如氧化铝、二氧化硅等)。这会导致衬底的严重划痕。所提出的抛光技术有望提高GaN和SiC器件的成品率。宽带隙(WBG)半导体如氮化镓(GaN)和碳化硅(SiC)已被迅速商业化，用于蓝光和紫外光发射器件以及高功率/高频器件。此外，在工程材料的应用方面也存在着强烈的商业兴趣，例如用于电力电子、控制和分配电路以及混合动力系统汽车的几种高功率/高温固态器件的GaN和SiC。

This Small Business Innovation Research (SBIR) Phase I research project will develop a novel gentle atomic scale surface polishing method for GaN and SiC based wide band-gap materials. This process is based on a chemical mechanical smoothening (CMS) technique, which is a unique subset of the novel chemical mechanical polishing (CMP) process developed by Sinmat to polish hard nitride and carbide materials. In this process, the chemicals in the slurry react to form a thin passivating layer (typically soft oxide layer) that is easily removed by the nanosized particles. The quality of polish would be determined by materials characterization and film growth techniques. Typically, conventional mechanical or chemo-mechanical polishing employs large ( 100 nm) hard particles (such as alumina, silica, etc.) that lead to significant scratching of the substrate. The proposed polishing technology is expected to increase the yield of GaN and SiC device. Wide band-gap (WBG) semiconductors such as GaN (gallium nitride) and SiC (silicon carbide) have been rapidly commercialized for blue and ultraviolet-light emitting devices, and high power/high frequency devices. Also, strong commercial interest exists in the application of engineering materials such as GaN and SiC for several high power/high temperature solid state devices for applications in power electronics, control and distribution circuits, and hybrid drive-train automobiles.