Nickel-titanium-based contact for n-type silicon carbide to combine high ohmic conductivity and mechanical properties

This paper reports a method to improve mechanical properties retaining the electrical properties of Ni-based ohmic contact material for n-type 4H-SiC. Ni/Ti bilayered films varying only in the thickness of the Ti layer were deposited on SiC substrates and annealed at 1273 K for a very short time in vacuum. The interfacial structures were analyzed by X-ray diffraction. The electrical and mechanical properties were measured by DC conduction test and constant-load scratch test, respectively. An appropriate thickness of the Ti layer on Ni improves the mechanical properties retaining the electrical properties by forming TiC instead of the free carbon.