FORMATION OF LOW TEMPERATURE OHMIC CONTACTS TO GaAs MESFETs AND GaAs/AlGaAs MODFETs.

Sintered ohmic contacts to MESFETs and MODFETs with very good specific contact resistivities have been formed using rapid thermal anneals at temperatures below the ohmic metal eutectic temperature for times less than one minute. Devices fabricated with these sintered contacts show DC performance as good as devices with alloyed ohmic contacts. The sintered contact provides a better surface morphology as well as a more uniform ohmic metal/GaAs interface than an alloyed contact. Accelerated aging at 300 degree C shows that sintered contacts degrade less rapidly than alloyed contacts. Thus, devices formed with sintered ohmic contacts show considerable promise for improved device performance and reliability.