A Novel Tungsten-Nickel Alloy Ohmic Contact to SiC at 900 ^\hbox

• Published in: IEEE electron device letters 2010-08, Vol.31 (8), p.791-793
• Main Authors: Okojie, R S, Evans, L J, Lukco, D, Morris, J P
• Format: Article
• Language: English
• Subjects: Amphoteric; Annealing; Argon; Chemistry; Conductivity; high temperature; Metallization; NASA; nickel; Ohmic contacts; Silicon carbide; Stability; Temperature sensors; tungsten
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2010.2050761

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 × 10 19 cm -3 , with specific contact resistances ρ sNd 's of 7.69 × 10 -4 and 5.81 × 10 -4 Ω · cm 2 , respectively, after rapid thermal annealing (RTA), and 5.9 × 10 -3 and 2.51 × 10 -4 Ω · cm 2 , 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 × 10 19 and N α > 1 × 10 20 cm -3 , with ρ sNd = 5 × 10 -5 and ρ sNa = 2 × 10 -4 Ω · cm 2 , respectively, after RTA, and ρ SNd = 2.5 × 10 -5 and ρ SNa = 1.5 × 10 -4 Ω · cm 2 after subsequent treatment at 900°C for 1 h in argon, respectively.