单晶SiC的电助光催化抛光及去除机理

为满足电子半导体等领域对SiC超光滑、无损伤和材料高效去除的要求，提出了电助光催化抛光SiC的新方法。研究了光催化剂种类及其pH值对抛光液氧化性和抛光效果的影响，讨论了材料的去除机理。结果表明：以p25型TiO2为光催化剂配制抛光液所获得的最大氧化还原电位为633.11 mV，材料去除率为1.18 μm/h，表面粗糙度Ra=0.218 nm；抛光后SiC表面氧化产物中，Si-C-O、Si-O和Si4C4O4的含量明显增加，SiC表面被氧化并被机械去除是主要的材料去除方式。

Electrical Enhanced Photocatalysis Polishing and Removal Mechanism for Single Crystal SiC

A new electrical enhanced photocatalysis polishing method for SiC was proposed herein to meet the requirements of ultra-smooth, non-damaging, and highly efficient in the fields of electronic semiconductor. Effects of different type photocatalysts and pH values on the oxygenation, and polishing performance of the slurries were studied. Material removal mechanism was discussed. The results show that the maximum oxidation-reduction potential of p25 type TiO2 slurries is as 633.11 mV, material removal rate is as 1.18 μm/h, and surface roughness Ra is as 0.218 nm. The proportion of oxidized species such as Si-C-O, Si-O, and Si4C4O4 increase noticeably on the polished silicon carbide surfaces, which indicates that the oxidation combined with mechanical action is main material removal mechanism.