Etching Characteristics of $Al_2O_3$ film Using $BCl_3$/He Plasma

$BCl_3$/He 플라즈마를 이용한 $Al_2O_3$ 박막 식각특성 연구

The etching characteristics of $Al_2O_3$ films using the inductively coupled plasma (ICP) was investigated. The etch gas was the mixture of $BCl_3$ and He. The effect of ICP source and bias powers on etch rate and etch selectivity to polycrystalline Si was investigated in the etch process of $Al_2O_3$. The etch rate of $Al_2O_3$ film was 23nm/min when the source power and bias power were 600W and 60W, respectively. The results also indicated that the etch selectivity to polycrystalline Si could not be enhanced to be higher than 1.0 by changing the ICP source power and bias power, under the experimental conditions used in the present work. Based on plasma parameters extracted from Langmuir probe data, the etching mechanism of $Al_2O_3$ film was discussed in detail.