Glass Micromachining with Sputtered Silicon as a Masking Layer

Abstract

In this work we present the not so commonly use of RF sputtered silicon as a masking layer for glass wet etching. The main advantages of this technique are low deposition temperature of silicon layer compared to PECVD and LPCVD processes, simplicity to use and low cost. Si layers were sputtered on 2.5x2.5cm(2) Pyrex 7740 substrates. The measured thickness of deposited silicon layer was 2.2 mu m. Silicon layer was patterned using lift-off technique. Etching was done in undilluted HF (49%) with estimated etch rate of similar to 8 mu m/min. Good quality of the glass surface without pinholes and notch defects on the glass etched edges suggests that using sp-Si layer as a masking material for glass etching is feasible.