Catalyst enhancement approach for improving the removal rate and stability of silica glass polishing via catalyzed chemical etching in pure water

Abstract

Precision polishing using transition metal catalysts such as Pt and Ru, called catalyst-refereed etching, is employed to fabricate atomically smooth surfaces on optical devices, realizing the designed device performance. However, the catalyst surface is covered with post-processing products during processing, drastically decreasing the removal rate. To address this issue, this paper proposes using an Ru-based alloy catalyst. Density functional theory calculation results show that doping Ti to Ru significantly reduces the adsorption energy of post-processing products, suggesting that the active site of the catalyst is easily recovered. When polishing silica glass, the Ru2Ti catalyst significantly improves the removal rate stability and enables the fabrication of an atomically well-ordered smooth surface, similar to that polished using a Pt or Ru catalyst.