A Novel Tungsten–Nickel Alloy Ohmic Contact to SiC at 900 $^{\circ}\hbox {C}$

A novel tungsten-nickel ohmic contact metallization on 4H-SiC and 6H-SiC capable of surviving temperatures as high as 900°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 × 10¹⁹ cm^-3, with specific contact resistances ρ_sNd´s of 7.69 × 10^-4 and 5.81 × 10^-4 Ω · cm², respectively, after rapid thermal annealing (RTA), and 5.9 × 10^-3 and 2.51 × 10^-4 Ω · cm², respectively, after subsequent soak at 900°C for 1 h in argon, and (2) ohmic contact on n- and p-type 6H-SiC having N_d > 2 × 10¹⁹ and N_α > 1 × 10²⁰ cm^-3, with ρ_sNd = 5 × 10^-5 and ρ_sNa = 2 × 10^-4 Ω · cm², respectively, after RTA, and ρ_SNd = 2.5 × 10^-5 and ρ_SNa = 1.5 × 10^-4 Ω · cm² after subsequent treatment at 900°C for 1 h in argon, respectively.