Contact resistance measurements on <i>p</i>-type 6H-SiC

Abstract

Specific contact resistance measurements are reported for Al-Ti ohmic contacts to epitaxial p-type 6H-SiC as a function of epitaxial doping. The circular transmission line method was used to measure the specific contact resistance including the sheet resistance of the epitaxial layer and the modified sheet resistance under the contact. Epitaxial layers with Al doping between 5.5×1015 and 2×1019 cm−3 yielded specific contact resistances between 2.9×10−2 and 1.5×10−5 Ω cm2. A good theoretical fit to the contact resistance data was obtained by assuming the metal-6H-SiC barrier height to equal 0.37 eV.