Chemical Etching of Dislocations Process on Sapphire

Abstract

In this work, the preferential chemical etching of dislocations on (0001) sapphire surface was investigated. The sapphire was etched by fused KOH etchant at fixed temperature for different time. The differences in the morphology of the etch pits on c-plane sapphire were observed by the optical microscope and atomic force microscopy. The results show that the optimal condition for dislocation displaying was etching 15 min or 25 min with fused KOH at 290 °C.The morphologies of the etch pits were changed from the triangle to the polygon and three kinds of increscent mechanisms about the etch pits are put forward and discussed in the paper.