The etching effect of trisdimethylaminoantimony on (001) planar substrates

Abstract

Reflection high energy electron diffraction (RHEED) oscillations during the etching of GaSb and GaAs (001) planar substrates by trisdimethylaminoantimony (TDMASb) are presented. Etching occurs by the reaction of surface Ga atoms with TDMASb-related species resulting to the formation of volatile Ga species. Results suggest that the etching of GaSb below 480°C is Sb 2 desorption limited. The addition of triethylgallium (TEGa) slows down the etching by providing Ga atoms that replace the volatilized ones. The addition of elemental antimony (Sb 4) changes the temperature dependence of the etching rate through the Sb surface coverage. Comparisons with the etching of GaAs by individual and combined fluxes of trisdimethylaminoarsenic (TDMAAs) and TDMASb show that the etching mechanism is influenced by the surface reconstruction which is determined primarily by the substrate and partly by the group V element the etchants carry.