Ir/Ni/W/Ni Ohmic contacts for n-type 3C-SiC grown on p-type silicon substrate

Abstract

In this work, Ohmic contacts to n-type 3C-SiC grown on p-type Si substrate employing Ni layer and Ir/Ni/W/Ni multilayers were investigated. Specific contact resistances of 2.57 × 10 ^–4 Ω · cm ^2 and 2.74 × 10 ^–5 Ω · cm ^2 were achieved with Ni layer and Ir/Ni/W/Ni multilayers, respectively, at an annealing temperature of 1050 °C. Samples were characterized using XRD, AFM and SEM. The result indicates the W is effective as a carbon absorbing and stabilizing layer and the presence of Ir cap layer facilitates lowering the surface roughness. As a result, the thermal stability and contact surface morphology of Ir/Ni/W/Ni/3C-SiC is greatly improved compared with Ni/SiC contact.

Keywords

• ohmic contacts
• Ir/Ni/W/Ni
• specific contact resistance
• thermal stability