电子回旋共振微波等离子体刻蚀α：CH薄膜的工艺

Etching α:CH films by electron cyclotron resonance microwave plasma

为了刻蚀出图形完整、侧壁陡直、失真度小的α:CH薄膜微器件,研究了有铝和无铝掩膜、气体流量比、工作气压对刻蚀速率的影响,并对纯氧等离子体刻蚀稳定性进行了研究。研究结果表明:在相同条件下,刻蚀速率随刻蚀时间变化不大;α:CH薄膜上有铝和无铝掩膜时,刻蚀速率相同;流量一定时,刻蚀速率随氩气和氧气体积比的增大而降低,当用纯氩气时,几乎没刻蚀作用;刻蚀速率随工作气压的增大而降低。实验中,得到最佳刻蚀条件是:纯氧气,流量4 mL.s-1,工作气压9.9×10-2Pa,微波源电流80 mA,偏压-90 V。

In order to obtain good etching effect, parameters as working pressure and ratio of gas flux for etching processes with and without AI mask were studied. The results are as follows： under the same conditions, etching rate varies little; whether or not having AI mask on α： CH films have no effect on etching rate; when gas flux is fixed, etching rate descends with bulk ratio of argon and oxygen increasing. In this study, the best etching conditions are using pure oxygen gas, flux of 4 mL·s^-1 , working pressure of 9.9×10^-2 Pa, microwave current of 80 mA, bias of --90 V. Under these conditions, fabricated micro-gear has vertical sidewall, small degree of distortion. Micro-gear could be released from the substrate using HF solution.