Abstract
In this study, $CeO_2$ thin films were etched with an addition of $Cl_2$ gas to $Ar/CF_4$ gas mixing in an inductively coupled plasma (ICP) etcher by the etching parameter such as RF power of 700 W, chamber pressure of 15 mTorr and dc bias voltage of -200 volts. The etch rate of $CeO_2$ films was 250 $\AA$/min with an addition of 10% $Cl_2$ gas to $Ar/CF_4$ gas mixture and the selectivity to SBT film was 0.4 at that condition. The surface reactions of the etched $CeO_2$ thin films were investigated by X-ray photoelectron spectroscopy (XPS). It was analyzed that Ce peaks were mainly observed in Ce-O bonds formed $CeO_2$ or $Ce_2O_3$ compounds. Cl peaks were detected by the peaks of Cl $2p_{3/2}$ and Cl $2p_{1/2}$. Almost all of Cl atoms were combined with Ce atoms like $CeCl_x$ or $Ce_x/O_yCl_z$ compounds.
본 연구에서는 ICP 식각장비에서 700 W의 RF전력과 -200 vo1t의 dc 바이어스 전압 및 15 mTorr의 반응로 압력에서 $Ar/CF_2$ 혼합가스에 $C1_2$가스를 첨가하면서 $CeO_2$ 박막을 식각하였다 최대식각 속도는 10%의 $C1_2$ 가스를 첨가하였을 시에 250 $\AA$/min이었고, 이 조건에서 SBT에 대한 식각 선택비는 0.4이었다. XPS를 이용하여 식각된 $CeO_2$ 박막의 표면반응을 검토하였다. Ce 피크는 대부분 $CeO_2$또는 $Ce_2O_3$형태로 Ce-O 결합상태임을 관찰할 수 있었다. 대부분의 Cl 피크는 CeClx 또는 $Ce_x/O_yCl_z$ 형태로 Ce 원자와 결합하고 있었다
