Etching characteristics of BST thin films for microwave application

초고주파 응용을 위한 BST 박막의 식각 특성

BST thin films were etched with inductively coupled $CF_4(C1_2+Ar)$ Plasmas. The maximum etch rate of the BST thin films was 53.6 nm/min for a 10 % $CF_4$ to the $Cl_2/Ar$ gas mixture at RF power of 700 W, DC bias of -150 V, and chamber pressure of 2 Pa. Small addition of $CF_4$ to the $Cl_2/Ar$ mixture increased chemical effect. Consequently, the increased chemical effect caused the increase in the etch rate of the BST thin films. To clarify the etching mechanism, the surface reaction of the BST thin films was investigated by X-ray photoelectron spectroscopy.