Comparison of glass etching properties between HCl and HNO3 solution

A comparison of glass etching properties between HCl and HNO₃ solution is presented in this paper, which allows us to predict the etched product´s shape under a variety of etching conditions, mask compensation and multiple processing steps. Four conclusions could be draw from the experiments. First, the best concentration ratio of the etching solution to protect the mask from damage and get a channel with depth of 40 μm is HF:HCl:NH₄F=5.5mol/L:4mol/L:2.5mol/L. Second, as the temperature increases, the longitudinal etching rate increases. However, the temperature has little influence on the lateral erosion ratio when the temperature gets high. Third, HCl has a better surface morphology against HNO₃ as an addition to solution. Last, the mask will introduce strain because of sputtering, which is harmful to the glass etching..