Silicon carbide semiconductor device, silicon carbide semiconductor assembly, and method of manufacturing silicon carbide semiconductor device

Abstract

A silicon carbide semiconductor device including a semiconductor substrate containing silicon carbide, a contact electrode, which is a silicide layer containing nickel, provided on a surface of the semiconductor substrate and forming an ohmic contact with the semiconductor substrate, and a metal connection layer provided on a surface of the contact electrode. The metal connection layer has a stacked structure in which on the surface of the contact electrode, a titanium layer, a nickel layer, and a gold layer are sequentially stacked. The titanium layer includes a carbon diffusion layer formed along an interface between the titanium layer and the contact electrode, a concentration of carbon being higher in the carbon diffusion layer than in a portion of the titanium layer other than the carbon diffusion layer. The titanium layer, the nickel layer and the gold layer have thicknesses of 100 nm to 300 nm, 1000 nm to 1500 nm, and 20 nm to 200 nm, respectively.