Title |
The Etching Mechanism of (Ba, Sr)TiO_3Thin Films in Ar/CF_4 High Density Plasma |
Authors |
김승범(Kim, Seung-Beom) ; 김창일(Kim, Chang-Il) |
Keywords |
Plasma Etching ; Ferroelectric ; BST ; XPS ; SIMS |
Abstract |
(Ba, Sr)TiO_3thin films were etched with a magnetically enhanced inductively coupled plasma (MEICP) at different CF4/Ar gas mixing ratios. Experimental was done by varying the etching parameters such as rf power, dc bias and chamber pressure. The maximum etch rate of the BST films was 1800{AA}/min under CF_4/(CF_4+Ar) of 0.1, 600 W/350 V and 5 mTorr. The selectivity of BST to Pt and PR was 0.6, 0.7, respectively. X-ray photoelectron spectroscopy (XPS) results show that surface reaction between Ba, Sr, Ti and C, F radicals occurs during the (Ba, Sr)TiO3 etching. To analyze the composition of surface residue after the etching, films etched with different CF_4/Ar gas mixing ratio were investigated using XPS and secondary ion mass spectroscopy (SIMS). |