Formation of low resistance contacts to p-type 4H-SiC using laser doping with an Al thin-film dopant source

Abstract

The effect of laser doping on the contact resistance of ohmic contact to 4H-SiC has been investigated. Laser doping was performed by irradiating a pulse-width stretched KrF excimer laser to an Al film coated on the surface of 4H-SiC. Doping and contact formation on the C-face were investigated. The doping was carried out while keeping the sample at room temperature. The experimental results suggest that the contact made of Ti/Al can achieve specific contact resistance as low as 4.0 × 10-6 Ωcm2 without additional heat treatment. The contact resistance is lower than that reported for ohmic contacts formed using ion implantation.