A low-temperature route to thermodynamically stable ohmic contacts to n-type 6H-SiC

Thermodynamically stable Ni silicide contacts were formed on n-type 6H-SiC using a remarkably modest thermal budget. Specifically, nickel monosilicide (NiSi) was formed at 300 deg. C via a solid-state reaction of a low-pressure chemical-vapor-deposited amorphous Si film with a sputter-deposited Ni overlayer. These contacts are ohmic with low specific contact resistance (ρc of 6.9x10-4 Ω cm2). Upon aging at 600 deg. C in air, ρc decreases rapidly, probably due to restructuring at the NiSi/SiC interface. After the initial decrease in ρc, the contact resistance remained in the 10-5 Ω cm2 range during aging at 600 deg. C for 300 h