Cl_2/Ar/O_2环境下使用光刻胶掩膜的感应耦合等离子体(ICP)刻蚀GaAs的研究

Inductively Coupled Plasma Etching of Subwavelength Grating Structures on GaAs in Cl_2/Ar/O_2 Environment

自1970年,元件制造首先采用感应耦合等离子体(ICP)刻蚀技术后,至今30多年,它的发展与集成电路和光电子器件发展密不可分,很大程度上,干法刻蚀的水平决定了整个产业的水平和规模。在本文中,本课题组使用ICP刻蚀技术刻蚀GaAs材料,在Cl_2/Ar/O_2环境下,研究控制刻蚀气流组成成分,刻蚀气流总速率等不同的刻蚀条件对于GaAs材料刻蚀速率的影响。实验表明,当刻蚀气流的成分不变的情况下,GaAs的刻蚀速率随着总刻蚀气流速率的增加而增加。刻蚀孔径的大小和Cl_2的含量多少也会影响GaAs的刻蚀速率。当O_2的含量在5%左右或者大于5%的实验中,GaAs材料的刻蚀表面的粗糙度几乎没有被刻蚀所影响。同时,给出了实验现象的简要分析和解释。

The subwavelength grating structure was fabricated by inductively coupled plasma etching（ ICP） in a mixture of Cl2/Ar/O2 on semi-insulating Ga As（ 100） substrate. The impact of the etching conditions,including but not limited to the compositions and flow-rates of Cl2,Ar and O2 mixture,aperture size,pressure,etching time and temperature,on the etching rate and surface morphologies was investigated with atomic force microscopy. The results show that the flow-rates and compositions of Cl2,Ar and O2,andetchingaperture sizeall have a major impact on the etching-rate and surface roughness. To be specific,at the fixed Cl2/Ar/O2 compositions,as the total flow-rate increased,the etching-rate increased; the etching aperture size and Cl2flow-rate affected the etching-rate to varying degrees. ICP etching little affected the Ga As surface roughness,simply because of - 5% oxygen. Possible ICP etching mechanisms were tentatively discussed.