Diamond deposition from CF4-H2 mixed gas by microwave plasma

Abstract

We have deposited diamond films from CF₄‐H₂ 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‐H₂ mixed gas. But it was observed from secondary ion mass spectroscopies that impurities (Si, F, and H) were present in the diamond films.