The ECR etching of GaAs using methane/hydrogen mixtures

Abstract

There exists an increasing interest in the development of low damage, dry etch processes for III–V materials. For the etching of GaAs, a wide range of gases has been employed, including: Cl₂, BCl₃, CCl₄, SiCl₄, CCl₂F₂ with and without various mixtures of O₂, H₂, He and Ar. Damage is of particular concern in devices such as MESFETs and HEMTs but it is possible to reduce it by achieving developing etch rate processes (and therefore, shorter etching times) and lower bombardment energies. Oxford Plasma Technology has been involved in the development of CCl₂F₂/He etching of GaAs by ECR based on the work of Rebecca Cheung¹ in which the low damage capabilities of ECR etching over RIE were proved.