Study on microstructure and semiconducting properties of doped c-BN-containing films

Films containing cubic boron nitride thin films were grown on Si substrates using RF plasma chemical vapor deposition, thermally assisted by a tungsten filament. The films obtained were characterized by scanning electron microscopy, infrared absorption and electron energy loss spectroscopy. The experimental results have shown that the microstructure and semiconducting properties of these films strongly depended on the deposition conditions, such as filament temperature. The content of c-BN in the films increased with increasing filament temperature. p-Type semiconducting c-BN films have been obtained by introducing Be powder into the deposition chamber. The Hall mobility with a carrier concentration of 4×1018 cm−3 was 215 cm2 V−1 s−1 at room temperature, and decreased with decreasing filament temperature. This may be ascribed to a reduction in the content of c-BN with decreasing temperature. Rectifying properties of W/p-type c-BN films have been observed in the 200–580°C range. The experimental results are also discussed briefly.