Study on surface roughness improvement of Fused Quartz after thermal and chemical post-processing

We present a study on the effects of thermal and chemical post-processing on the surface quality of Fused Quartz, a preferable material for vibratory gyroscopes. In this study, we included the effects of thermal reflow, potassium hydroxide (KOH) etching, Buffered Oxide Etching (BOE), 10:1 hydrogen fluoride and hydrogen chloride solution (HF/HCl) etching, and RCA-1 surface treatment. We concluded that thermal reflow of fused quartz at 1300°C for one hour achieves the best result, followed in effectiveness by the RCA-1 surface treatment, while KOH etching, BOE, and HF/HCl etching are shown to deteriorate the surface quality. The effects of thermal reflow were studied for 2-D and 3-D geometries. The improvement in surface roughness of microstructures was shown to directly correlate to improvements in the quality factor.