Etching characteristic and mechanism of BST thin films using inductively coupled Cl 2/Ar plasma with additive CF 4 gas

Abstract

BST thin films were etched with inductively coupled CF 4/(Cl 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.