마이크로파 플라즈마 CVD 방법으로 Si,Inconel 600 및 Steel 모재위에 증착된 다이아몬드 박막의 증착특성

Abstract

The deposition characteristics of diamond films were investigated for three different substrates : Si, Inconel 600 and steel. Diamond films were prepared by microwave plasma CVD method using CH4, H₂ and O2 as reaction gases. The deposited films were analyzed with SEM, Raman spectroscopy and ellipsometer. For Si substrate, diamond films were successfully obtained for most of the deposition conditions used in this study. As the $CH_4$ flow rate decreased and the O2 flow rate increased, the quality of the film was improved due to the reduced non-diamond phase in the film. For Inconel 600 substrate, the surface pretreatment with diamond powders was required to deposit a continuous diamond film. The films deposited at temperatures of 600℃ and 700℃ had mainly diamond phase, but they were peeled off locally due to the difference in the thermal expansion coefficient between the substrate and the deposited films. The films deposited at 500℃ and 850 ℃ had only the graphitic carbon phase. For steel substrate, all of the films deposited had only the graphitie carbon phase. We speculated that the formation of diamond nuclei on the steel substrate was inhibited due to the diffusion of carbon atoms into the steel substrate which has a large amount of carbon solubility.