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°C is reported. Preliminary results revealed the following: (1) ohmic contact on n-type 4H-SiC having net doping levels (Nd's) of 1.4 and 2 × 1019cm-3, with specific contact resistances ρsNd's of 7.69 × 10-4and 5.81 × 10-4Ω · cm2, respectively, after rapid thermal annealing (RTA), and 5.9 × 10-3and 2.51 × 10-4Ω · 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 Nd> 2 × 1019and Nα> 1 × 1020cm-3, with ρsNd= 5 × 10-5and ρsNa= 2 × 10-4Ω · cm2, respectively, after RTA, and ρSNd= 2.5 × 10-5and ρSNa= 1.5 × 10-4Ω · cm2after subsequent treatment at 900°C for 1 h in argon, respectively.