Ohmic contacts to <i>n</i>-GaAs using low-temperature anneal

Abstract

The low-temperature alloying behavior of AuGe films deposited on n-type GaAs substrates (N = 2×1018 cm−3) has been investigated. Ohmic contacts were obtained using a postdeposition anneal in reducing atmosphere (H2 15%, N2 85%) at 275 °C for 120 sec with contact resistivities of 2.5×10−5 W cm2. These contacts are highly reproducible and exhibit more stable high-temperature aging characteristics and better surfaces than do the more conventional AuGe-Ni-alloyed contacts on n-GaAs.