The Formation of The Hexagonal Pyramid Facets on Wet Etching Patterned Sapphire Substrate

Abstract

Currently, the wet etching patterned sapphire substrate (PSS) has attracted much attention for its high production yield. After etching in hot mixed H2SO4 and H3PO4 solution, the several etched facets were exposed on sapphire substrate. In this study, a series of etching process was used to investigate the formation. As shown in Fig. 1, when SiO2 mask still remained, the structure of PSS comprised of six facets {3 (4) over bar 17}. When SiO2 mask were etched away, beside six facets, there were three extra facets {1 (1) over bar 05} exposed on the top.