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 300degreesC 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 (rho(c) of 6.9x10(-4) Omega cm(2)). Upon aging at 600degreesC in air, rho(c) decreases rapidly, probably due to restructuring at the NiSi/SiC interface. After the initial decrease in rho(c), the contact resistance remained in the 10(-5) Omega cm(2) range during aging at 600degreesC for 300 h. (C) 2004 American Institute of Physics.