Nitrogen implanted high voltage, planar, 6H-SiC N/sup +/-P junction diodes

Abstract

High voltage (700 V), planar, 6H-SiC N/sup +/-P junction diodes have been successfully fabricated by nitrogen implantation at room temperature using a deposited and patterned silicon dioxide layer as the mask. The diodes showed excellent rectification and were able to operate at temperatures as high as 250/spl deg/C with leakage current density less than 1/spl times/10/sup -4/ A/cm/sup 2/. The dominant current conduction mechanism during forward bias was found to be recombination in the depletion region. The forward voltage drop of these diodes at 100 A/cm/sup 2/ was found to be high (13.5 V) due to the large parasitic series resistance of the thick p-type substrate. The series resistance was found to decrease with increasing temperature due to improved ionization of the dopant in the P-type substrate leading to a reduction in forward drop.