SURFACE CLEANING OF GAAS BY IN-SITU CHEMICAL BEAM ETCHING

Chemical beam etching using AsCl3 has been shown to provide accurate etch rate control at the atomic level, mask feature transfer at submicron scale, and a clean damage-free surface for regrowth. The etching process can be maintained in a two-dimensional fashion, if the etching conditions are designed to enable efficient cation diffusion that smooths the microroughness. In this work, we show from etching the heavily Be-doped GaAs surface that the in situ etching prior to growth is potentially a useful method for etch cleaning the surface. However, the effectiveness of this method depends on the ability to form volatile species with the contaminant in competition with the formation of group III chloride. © 1994 American Institute of Physics.