Fabrication of Silicon Carbide PIN Diodes by Laser Doping and Planar Edge Termination by Laser Metallization

Abstract

Silicon carbide PIN diodes have been fabricated using a direct write laser doping and metallization technique. Trimethyaluminum (TMA) and nitrogen are precursors used to laser dope p-type and n-type regions, respectively, and a 4.3 µm p-type doped junction and 4 µm ntype doped junction are fabricated in semi-insulating 6H-SiC wafers. Rutherford backscattering studies show that no amorphization occurred during the laser doping process. A planar edge termination is fabricated by laser metallization in argon ambient to form a high resistivity layer. With this termination, the leakage current of the PIN diodes can be suppressed effectively compared to that of diodes without edge termination. The performance of the diodes can also be tailored by shrinking the active area of the diode and by conventional annealing. EXPERIMENT DETAILSE9.3.1 Mater. Res. Soc. Symp. Proc. Vol. 864