GROWTH OF CUBIC BORON-NITRIDE THIN-FILMS BY A FIELD-IONIZATION SOURCE-ASSISTED PULSED-LASER DEPOSITION

Cubic boron nitride (cBN) thin films have been deposited on silicon (1 00) substrate using ArF pulsed excimer laser for ablating hexagonal bo ron nitride (hBN) targets and a field-ionization source for activating N-2. The structure and composition of the films have been measured by Fourier transformation infrared spectroscopy (FTIR), X-ray diffractio n (XRD) analysis and Auger electron spectroscopy (AES). The FTIR trans mittance spectrum shows that there are a strong absorption peak at 109 5.8 cm(-1) corresponding to cBN and a very weak absorption band at 138 0 cm(-1) corresponding to hBN. The XRD pattern shows that there is a p eak at 43.30 degrees corresponding to the cBN (111) face. These result s show that the films are mainly cBN including a small amount of hBN. AES depth-profiling experiments show that the relative atomic ratio of N to B in the films is obviously increased by using a field-ionizatio n source of about 700 V during the deposition process.