Material‐Selective Chemical Etching in the System InGaAsP / InP

Abstract

Selective chemical etching of substrates in the III–V system is described. A new etchant composed of hydrochloric and phosphoric acids is proposed, and a detailed description of application is provided. It is shown that illumination and the intentional introduction of defects on the surface of substrate material greatly facilitate its removal even from the slow etching (111)A face. Thus on LPE layers grown on (111)B‐oriented substrates, both the (111)Ga,In and (111)As,P faces of the epilayers can be exposed.