Etching Evolutions and Surface Morphologies of Sapphire Hemispheres Under Different Etchant Concentration Conditions

In this paper, the etching evolution law and surface morphology characteristics of sapphire hemispheres under different etchant concentration conditions are analyzed comprehensively in the light of the atomic structure and etching rates of sapphire. Firstly, etching rate distributions of the sapphire hemispheres at various concentration conditions (volume ratios of H2SO4 and H3PO4 are 1/1, 3/1 and 6/1) with the C-plane as the rotation center is obtained through etching experiments of sapphire hemispherical specimens, and etching evolutions of hemispheres are simulated and analyzed by applying the Level-Set method. It helps to design the etching time of the hemisphere reasonably. Then, the influence of etchant concentrations on the etching of hemispheres is analyzed on the basis of the characteristics of the etching rate distributions under different concentration conditions. Finally, the formation and the characteristic variability of hemispherical etching morphologies at various concentration conditions are analyzed in the light of the etching rates of planes and their atomic structures. It helps to improve the etching process of sapphire and the processing quality of etched structures of sapphire.[2024-0139]