Comparison of damage in the dry etching of GaAs by conventional reactive ion etching and by reactive ion etching with an electron cyclotron resonance generated plasma

We have developed a high-resolution etch for GaAs in an electron cyclotron resonance-radio frequency (ECR-rf) hybrid reactor using CCl2F2/He as the etch gas. Surface contamination from the gas and from the electrodes was found to affect the etching process as well as etched substrate. Surface damage studies using Schottky diode and x-ray photoelectron spectroscopy analysis and sidewall damage characterization using room-temperature conductance measurements of n+-GaAs quantum wires indicate that very little damage is caused by ECR-rf reactive ion etching compared with conventional rf reactive ion etching (RIE). In addition, the small residual damage after ECR-rf RIE is measured to increase with etching time.