A non-alloyed ohmic contact formation on n-type GaAs

Abstract
The ohmic contact characteristics of nickel antimonide in n‐type GaAs semiconductor circuits are evaluated. Deposition techniques, structural, and electrical properties were studied. The structural analysis revealed a well‐defined, sharp interface of a polycrystalline nickel antimonide phase with various solid‐phase interactions at higher annealing temperatures. The sheet resistance of 1000‐Å‐thick films decreased to 7–10 Ω/⧠ after annealing at 400 °C. The ohmic contact formation was demonstrated using transmission line measurements. Subtractive etching of the contacts was accomplished by a wet etchant system which was found not to attack the GaAs substrate.