SURFACE DAMAGE ON GaAs INDUCED BY REACTIVE ION ETCHING AND SPUTTER ETCHING.

GaAs surface damage induced by reactive ion etching (RIE) using various gases is compared with sputter etching using inert gases. Anisotropic etching of GaAs with minimal surface damage can be obtained with most of the RIE conditions used. Sputter etching using inert gases introduces substantial damage on the GaAs surface, and the degree of damage is inversely proportional to the ion mass. In addition, we have found that the damage induced by Ar sputter etching can be greatly reduced by the introduction of reactive gases during etching. Recovery of the diode characteristics is observed after removing 500A of the etched surface using wet chemical solution or by removing 200A of the etched surface using RIE Cl//2 at 30V.