Nitrogen impurity incorporation behavior in a chimney HTCVD process: pressure and temperature dependence

Experimental results are presented for residual nitrogen incorporation in both Si and C face 4H SiC epilayers using the high temperature chemical vapor deposition (HTCVD) process in a chimney reactor. The influence of total pressure, process temperature and input C/Si ratio on the residual nitrogen doping is studied. The results are further confirmed by intentional nitrogen doping experiments. Activation energies of 200 kcal/mol for Si face and 108 kcal/mol for C face samples are obtained for nitrogen incorporation. Possible incorporation mechanisms related to both surface and gas phase kinetics are discussed.