Low Contact Resistivity Mn/Au/Ti/Pd/Au P-Ohmic Contacts for HBTs

Obtaining good p-ohmics to the base layers of AIGaAs/GaAs HBTs have been difficult due to metal spiking and instability of the contacts to subsequent processing temperatures. To avoid spiking, non-alloyed contacts have been traditionally used. In this paper, we present a stable, non-spiking, low contact resistivity alloyed p-ohmic contact to HBT structures.