A common metallization scheme for ohmic contacts to n-type and p-type GaAs: the AlNiSn system

Abstract

Results are presented on the use of AlNiSn metallization system as a common metallization scheme to realize ohmic contacts to both p-type and n-type GaAs. The ohmic contacts yield a specific contact resistance in the range from 10 −5 to 10 −4 ω cm 2 for both p-type and n-type GaAs. The presence of a cap during the annealing step brings about a significant reduction in the specific contact resistance. The surface morphology of the contacts is smooth and uniform unlike the usually rough and uneven surface morphology of the (AuGe)/Ni ohmic contacts to n-GaAs.