A new approach in impurity doping of 4H-SiC using silicidation

Oxidation and silicidation have been found to enhance phosphorus diffusion and incorporation in 4H-SiC. Depth profiling by secondary ion mass spectrometry showed significant concentration of phosphorus in the order of 1018–1019 cm−3 in the near-surface region of 4H-SiC in both oxidation and silicidation-assisted phosphorus-diffused samples. However, silicidation was remarkably more effective than oxidation in promoting phosphorus diffusion, producing comparable phosphorus concentration at even greater depth at a temperature of only 900 °C. Specific contact resistance values of the phosphorus-doped samples confirmed feasibility of this method in ohmic contact fabrication on SiC.