강유전체 YMnO3 박막 식각에 대한 CF4 첨가효과

Abstract

The etching behaviors of the ferroelectric YMnO3 thin films were studied by an inductively coupled plasma (ICP). The maximum etch rate of YMnO3 thin film is 300 Å/min at Ar/Cl2 of 2/8, RF power of 800W, dc bias voltage of 200V, chamber pressure of 15mTorr and substrate temperature of 30℃. Addition of CF4 gas decrease the etch rate of YMnO3 thin film. From the results of XPS analysis, nonvolatile YFx compounds were found on the surface of YMnO3 thin film which is etched in Ar/Cl2/CF4 plasma. The etch profile of YMnO3 film is improved by addition of CF4 gas into the Ar/Cl2 plasma. These results suggest that YFx compound acts as a sidewall passivants which reduce the sticking coefficient of chlorine on YMnO3.