The Effect of Chemical Etching on the Relief of the Grinded Surface of Silica Glass

ABSTRACT The results of a study of the surface relief of grinded silica glass plates chemically etched with two different solutions containing fluoride ions are presented. Unlike other studies, the surface relief was analyzed using the Allan variance method, which made it possible to quantitatively determine the surface roughness associated with defects of different sizes. The analysis revealed that the surface relief formed during chemical dissolution of the damaged layer depends primarily on the preceding mechanical treatment of the glass, rather than on the chemical etching conditions. It has been shown that preannealing silica glass reduces the surface roughness formed during chemical etching. It is concluded that to achieve low surface roughness in silica glass samples, it is necessary to improve the quality of mechanical processing and anneal before chemical treatment. The presented results also demonstrate the effectiveness of using the Allan variance method for analyzing solid surface roughness.