High-temperature stable W5Si3/In0.53Ga0.47As ohmic contacts to GaAs for self-aligned HBTs

Metallurgicalp and electrical stabilities of W5Si3/In0.53Ga0.47As ohmic contacts to n-GaAs are studied using backscattering and TLM measurements. It is found that W5Si3/In0.53Ga0.47As ohmic contacts are stable even after annealing at 900°C for 5 sec. We propose and demonstrate a self-aligned HBT fabrication process using the high-temperature stable ohmic contacts for emitter-electrodes.