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 tungste n filament. The films obtained were characterized by scanning electron micr oscopy, infrared absorption and electron energy loss spectroscopy. The expe rimental results have shown that the microstructure and semiconducting prop erties of these films strongly depended on the deposition conditions, such as filament temperature. The content of c-BN in the films increased with in creasing filament temperature. p-Type semiconducting c-BN films have been o btained by introducing Be powder into the deposition chamber. The Hall mobi lity with a carrier concentration of 4 x 10(18) cm(-3) was 215 cm(2) 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 decreasin g temperature. Rectifying properties of W/p-type c-BN films have been obser ved in the 200-580 degreesC range. The experimental results are also discus sed briefly. (C) 2001 Elsevier Science B.V. All rights reserved.