MEMS 적용을 위한 Thermal CVD 방법에 의해 증착한 SiC막의 반응성 이온 Etching 특성 평가

Abstract

In recent years, silicon carbide has emerged as an important material for MEMS application. In order to fabricate an SiC film based MEMS structure by using chemical etching method, high operating temperature is required due to high chemical stability. Therefore, dry etching using plasma is the best solution. SiC film was deposited by thermal CVD at the temperature of 1000 and pressure of 10 torr. SiC was dry etched with a reactive ion etching (RIE) system, using SF6/O2 and CF4/O2 gas mixture. Etch rate has been investigated as a function of oxygen concentration in the gas mixture, rf power, working pressure and gas flow rate. Etch rate was measured by surface profiler and FE-SEM. SF6/O2 gas mixture showed higher etch rate than CF4/O2 gas mixture. Maximum etch rate appeared at RF power of 450W. O2 dilute mixtures resulted in an increasing of etch rate up to 40%, and the superior anisotropic cross section was observe.