Au-Ge-Ni-Ti Ohmic Contacts on Gallium Arsenide

Abstract

ABSTRACTThe influence of titanium additions on the microstructure of Au-Ge-Ni ohmic contacts on gallium arsenide has been evaluated. Sequentially deposited layers of Ge, Au and Ni were topped with a titanium layer. The titanium formed a native titanium oxide on the upper surface of the contact which helped to maintain a continuous film during the anneal. Both the as-deposited and the annealed microstructures were studied with the use of electron microscopy techniques. In order to examine thoroughly the various phases which form in the annealed contact, unique specimen preparation procedures were used to fabricate a single plan-view specimen in which it was possible to examine the microstructure at various depths.