Effect of ion beam mixing on the evolution of arsenic from the Au-GaAs system

In order to study the interaction of gold and GaAs during high temperature heat treatment (contact technology) of Au-GaAs structures accompanied by evolution of arsenic and interdiffusion of Au and GaAs a comparison of arsenic loss measurements and Rutherford backscattering spectrometry for annealed non-implanted and annealed Xe2+ pre-implanted Au-GaAs structures is presented. Without implantation the interdiffusion was inhibited at lower temperatures by an interface contamination, while pre-implantation broke up the thin layer and enhanced the reaction between Au and GaAs, enabling the Ga penetration into the gold layer. This effect is indicated by the evolved gas analysis curves, too. The temperature of maximum arsenic loss was shifted to about 1000 lower because of the formation of a Ga2Au layer