Reduction of Dry Etch Damage to GaAs Using Pulse-Time Modulated Plasmas

We report on the etching characteristics of GaAs and AlGaAs in capacitive plasmas modulated at a pulse timing of a few milliseconds. Under such conditions, we obtained GaAs etch rates in the range, with selectivities over AlGaAs of . The effects of plasma-induced damage to GaAs were also measured by diode ideality factor and barrier height measurements. The electrical characteristics of the diodes show less prominent dry etch damage than in the continuous reactive ion-etching conditions, a promising result for optimized gate recess in the fabrication of high-electron-mobility transistors.