A study on the etching properties of (Ba,Sr)$TiO_3$ film by high density plasma

고밀도 플라즈마에 의한 (Ba,Sr)$TiO_3$막의 식각특성 연구

(Ba,Sr)$TiO_3$ thin films were etched with $Cl_2$/Ar gas mixing ratio in an inductively coupled plasma (ICP) by varying the etching parameter such as f power, do bias voltage, and chamber pressure. The etch rate was $560{\AA}/min$ under Cl_2/(Cl_2+Ar)$ gas mixing ratio of 0.2, rf power of 600 W, do bias voltage of 250 V, and chamber pressure of 5 mTorr, At this time, the selectivity of BST to Pt, $SiO_2$ was respectively 0.52, 0.43. The surface reaction of the etched (Ba,Sr)$TiO_3$ thin films was investigated with X-ray photoelectron spectroscopy (XPS).