A Novel Tungsten-Nickel Alloy Ohmic Contact to SiC at 900 °C

A novel tungsten-nickel ohmic contact metallization on 4H-SiC and 6H-SiC capable of surviving temperatures as high as 900 degrees C is reported. Preliminary results revealed the following: 1) ohmic contact on n-type 4H-SiC having net doping levels (N-d's) of 1.4 and 2 x 10(19) cm(-3), with specific contact resistances (rho sNd)'s of 7.69 x 10(-4) and 5.81 x 10(-4) Omega . cm(2), respectively, after rapid thermal annealing (RTA), and 5.9 x 10(-3) and 2.51 x 10(-4) Omega . cm(2), respectively, after subsequent soak at 900 degrees C for 1 h in argon, and 2) ohmic contact on n- and p-type 6H-SiC having N-d > 2 x 10(19) and N-a > 1 x 10(20) cm(-3), with (rho sNd) = 5 x 10(-5) and (rho sNd) = 2 x 10(-4) Omega . cm(2), respectively, after RTA, and (rho sNd) = 2.5 x 10(-5) and (rho sNd) = 1.5 x 10(-4) Omega . cm(2) after subsequent treatment at 900 degrees C for 1 h in argon, respectively.