BCl3/Ar 유도 결합 플라즈마 시스템에서 이온 에너지 분포에 따른 HfO2 박막의 식각

Abstract

- In this work, we investigated etching characteristics of HfO2 thin film and Si using inductive coupled plasma(ICP) system. The ion energy distribution functions in an ICP system was analyzed by quadrupole mass spectrometer(QMS) with an electrostatic ion energy analyzer. The maximum etch rate of HfO2 thin film is 85.5 nm/min at a BCl3/(BCl3+Ar) of 20 % and decreased with further addition of BCl3 gas. From the QMS measurements, the most dominant positive ion energy distributions(IEDs) showed a maximum at 20 % of BCl3. These tendency was very similar to the etch characteristics. This result agreed with the universal energy dependency of ion enhanced chemical etching yields. And the maximum selectivity of HfO2 over Si is 3.05 at a O2 addition of 2 sccm into the BCl3/(BCl3+Ar) of 20 % plasma.