Structural and electrical characterizations of oxynitride films on solid phase epitaxially grown silicon carbide

Abstract

We have investigated the structural and electrical properties of as-prepared and rapid thermal oxynitride films on C + implanted solid phase epitaxially grown SiC. The oxynitride was grown using N 2 O. The C concentration of the samples was estimated to be 1, 2 and 5 at. %. From the infrared spectra, samples with 1 and 2 at. % carbon showed that the carbon was substitutionally incorporated into the silicon. No precipitation of SiC was detected. However, for the 5 at. % C sample, some precipitation was observed as indicated by a broad peak at ~800 cm -1 . The oxynitride films showed the Si-O-Si stretching mode at ~1100 cm -1 . The shoulder at 980-1067 cm -1 was due to the O-Si-N bond. The peak at 830 cm -1 was due to the Si-N and Si-C bonds and C-O complex vibrational mode was observed at 663 cm -1 . Electrical characterization of the oxynitride films was carried out using the MOS capacitor structure. The interface state density was found to range between 5.7×10 11 to 3.35×10 12 cm -2 eV -1 and increased with an increase in the C concentration. The electrical breakdown field was found to be in the range of 5-7 MV cm -1 and reduced with an increase in C concentration. The charge-to-breakdown value was measured and decreased with an increase in C concentration.