论文部分内容阅读
利用感应耦合等离子体(ICP)进行了InSb刻蚀研究。为了实现高的刻蚀速率同时保证光滑的刻蚀表面,研究中在CH4/H2/Ar气氛中引入了Cl2。研究发现,对InSb的刻蚀速率随Cl2含量及ICP功率的升高而线性增加。当Cl2含量增加到超过12%或ICP功率大于900 W时,刻蚀表面变得粗糙,而易引起刻蚀损伤的直流偏压随ICP功率的升高而降低。此现象归因于刻蚀副产物InCl3在样品表面的聚集进而妨碍均匀刻蚀反应所致。当样品温度从20℃提高到120℃,刻蚀速率及表面粗糙度无明显变化。通过试验研究,实现了对InSb的高速率、高垂直度刻蚀,刻蚀速率大于500 nm/min,对SiO2掩模刻蚀选择比大于6,刻蚀表面光洁,刻蚀垂直度可达80°。
InSb etching was performed using inductively coupled plasma (ICP). In order to achieve a high etch rate while ensuring a smooth etched surface, Cl2 was introduced into the CH4 / H2 / Ar atmosphere. The results show that the etching rate of InSb linearly increases with the increase of Cl2 content and ICP power. When Cl2 content is increased to more than 12% or ICP power is more than 900 W, the etched surface becomes rough, while the DC bias voltage which easily causes etching damage decreases with the increase of ICP power. This phenomenon is attributed to the aggregation of the etching by-product InCl3 on the sample surface, which hinders the uniform etching reaction. When the sample temperature is raised from 20 ℃ to 120 ℃, there is no obvious change of etching rate and surface roughness. Through the experimental research, the high-rate, high-perpendicularity etching of InSb is achieved with the etching rate greater than 500 nm / min and the selective ratio of etching to SiO2 mask greater than 6, the etched surface is smooth and the verticality of etching is up to 80 °.