We report on ohmic contacts on β-SiC. The contacts were formed using Ni, NiCr, W, Ti, Wsi2 and TiSi2. Contact resistance measurement and Auger Electron Spectroscopy (AES) were used to study annealing effects on contact materials. Auger analysis of Ni-SiC system indicates that during heat treatment, Ni reacts with Si to form silicide. Similar results are found for NiCr-SiC contacts.
Minimum contact resistance of tungsten and titanium on SiC is measured to be 6.l×10−3 ohm/cm2 and 7.6×10−3 ohm/cm2, respectively. High temperature annealing deteriorates both contacts although for titanium contacts the resistance increases less dramatically as compared to tungsten contacts. The silicides of tungsten and titanium yield lower contact resistance than metallic W and Ti contacts. The contact resistance for Wsi2 and TiSi2 after heat treatment decreases to 3.0×10−4 ohm/cm2 and 1.1×10−4 ohm/cm2, respectively.