Laser Direct Write Doping And Metallization Fabrication Of Silicon Carbide Pin Diodes

A novel laser direct write doping and electrical property conversion technique has been used to fabricate prototype SiC PIN diodes on n-type 4H-SiC wafers. Two different diode structures are fabricated: (1) a laser aluminum doped top p+/p region on a n-type 4H-SiC wafer segment with a low doped n-type SiC epitaxial layer; and (2) the same laser doped top p +/p region on the same substrate and a laser heavily nitrogen doped n+ region at the bottom. A simple Schottky diode fabricated on the same substrate medium was used for a comparison. In the laser doped n + region conductors are directly fabricated by the formation of electrically conductive surface carbon rich phase. The results show that laser fabrication of PIN diodes, having a 10 μm epilayer, exhibits higher dopant concentrations and indicate promising breakdown voltages and forward voltage drops without edge termination