Effects of Si interlayer on nickel and platinum ohmic contacts for N-type SiC

Platinum and nickel contacts with and without silicon addition were prepared and compared on 4H and 6H silicon carbide. After deposition, samples were gradually annealed up to 1150°C. Si addition into Pt contact was beneficial for decreasing of contact resistivity on 4H-SiC, but on 6H-SiC the effect was negligible. In the case of Ni-based contacts, the influence of Si was more pronounced for samples on 6H-SiC substrate, but after annealing at temperatures higher than 850°C similar values of contact resistivity were achieved for contacts with different Ni-Si ratio on both 4H and 6H-SiC.