초록
13.56 MHz rf플라즈마를 이용하여 증착된 DLC(diamond-like carbon) 박막의 광학적 특성에 대해 조사하였다. $CH_4$가스를 원료가스로 하여 PECVD법에 의해 DLC 박막을 형성하였으며 이때 RF power, working pressure, 보조가스의 종류 및 양에 따른 투과도(transmittance)와 optical band gap의 변화를 관찰하였다. RF power가 증가하고 working pressure가 높을수록 optical band gap이 감소하는 결과를 얻을 수 있었고. FT-IR분석을 이용하여 탄소-수소 결합 양을 관찰함으로써 DLC 박막의 결합구조 변화를 증명할 수 있었다. 그리고 수소와 질소를 첨가한 경우 증착시 탄소-수소 결합을 끊는 역할을 하여 optical band gap이 감소하는 결과를 얻을 수 있었다.
In this study, the optical properties of diamond-like carbon(DLC) films, which was synthesized by 13.56 MHz rf plasma enhanced chemical vapor deposition system(PECVD), were investigated. We observed the variation of the transmittance and optical band gap with respect to deposition condition. The change of the transmittance and optical band gap of the DLC films were investigated as a function of RF power, working pressure, and additional gas. The optical band gap decreased with the increase of RF power and working pressure. We could verify the bond structures change of DLC films by observing the content of hydrogen using FT-IR spectroscopy. And the addition of hydrogen and nitrogen decreased the optical band gap by the breakage of C-H bond of DLC films during the deposition.
