Boron and aluminum doping by diffusion into n-type 4H–SiC Si-face substrates was carried out at 1800 to 2000C. Secondary ion mass spectroscopy was employed to obtain the impurity profiles, which showed that linearly graded boron profile and shallow aluminum profiles were achieved, which may be a promising application in SiC device fabrication, such as p–n diode or ohmic contact. Characterization of high temperature processing influence on SiC surface morphology was performed. Elemental boron and aluminum carbide were determined to be the best candidates as an impurity source materials for realizing p-type diffusion.

Boron and Aluminum Diffusion into 4H–SiC Substrates. A.Kubiak, J.Rogowski: Materials Science and Engineering B, 2001, 176[4], 297–300