Arsenic polyps on contacts to GaAs

Features resembling polyps composed of As/sub 2/O/sub 3/ observed on GaAs devices under two conditions are discussed. In one case they appear on top of multilayer metal contacts on GaAs and are related to the presence of Au in the contact materials that reacts with underlying GaAs. In the other case, they appear both on metal and exposed GaAs surfaces and are related to the presence of humidity acting under the influence of metal-semiconductor contact potentials.<
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