DIAMOND DEPOSITION FROM CF4-H2 MIXED GAS BY MICROWAVE PLASMA

We have deposited diamond films from CF4-H-2 mixed gas by microwave plasma chemical vapor deposition method. The diamond films were characterized by scanning electron microscopy, x-ray diffraction, Raman spectrometry, and secondary ion mass spectrometry. (111) peak line of diamond crystal observed by x-ray diffraction and the peaks at 1333 cm-1 in the Raman spectroscopies of the deposited films showed that the films consisted of diamond. We observed that the quality of diamond films got better as the concentration (from 2.5% to 40%) of CF4 (tetrafluoromethane) got lower. It was observed from the optical emission spectra that CF, CF2, CF3, CH, and C2 fragments existed in the microwave plasma of CF4-H-2 mixed gas. But it was observed from secondary ion mass spectroscopies that impurities (Si, F, and H) were present in the diamond films.