Ultra-smooth dry etching of GaAs using a hydrogen plasma pretreatment

Abstract

The authors have attained extremely smooth etched surfaces on GaAs using a hydrogen plasma pretreatment before etching. The resultant morphology exhibits smooth surfaces since the etching proceeds uniformly through the GaAs without micromasking effects arising from a nonuniform surface oxide. They report the effects of hydrogen plasma treatments before RIE of GaAs in two different reactors using a SiCl{sub 4} plasma. Optimization of H{sub 2} plasma pretreatments has produced improvements in RMS roughness greater than 1 order of magnitude (22.4 to 1.51 nm).