Metallurgy and Morphology of the Interface of AuGe Ohmic Contact to GaAs

Abstract

ABSTRACTScanning electron microscopy and energy dispersive x-ray analysis have been used to study the formation of AuGe ohmic contacts to GaAs. Both sintering and alloying of the metallization result in deep trenches and spikes. Lateral growth of the metallization at the perimeter of the contact is also reported. In situ analysis during the formation of the ohmic contact has demonstrated the formation of a solid phase complex of Au-Ge-As and the rapid loss of As at 450°C. The influence of the Au-Ge-As complex and the loss of As on the specific contact resistivity is discussed.