深槽刻蚀工艺参数及干法清洗工艺的研究

Study on Process Parameters and Dry Cleaning Process of Deep Reactive Ion Etching

本文研究了博世(Bosch)工艺的工艺参数及清洗工艺对刻蚀结果的影响。通过调节工艺参数(包括SF6气体的流量、工艺气压、上电极(Source)功率、下电极偏压(bias)功率、C4F8钝化切换时间)研究其对刻蚀速率、选择比及刻蚀形貌的影响,得到了工艺参数的一般性规律及本实验的最佳工艺条件,刻蚀速率1.77μm/min,选择比为91.23,深槽CD差在-0.2μm左右,刻蚀形貌为倒梯形且接近垂直。同时对干法清洗工艺进行了研究,解决长草异常的同时,提供了一种深槽刻蚀工艺维护的方法。

The influence of the process parameters of Bosch process and the cleaning process on the etching results were studied in this paper. We investigated the influence of the process parameters (including SF6 gas flow, chamber pressure, Source power, bias power, C4F8 passivation time) on etch rate, selectivity and etching morphology. Through the above experiments, the general rules of the process parameters and an optimization recipe was got, which etching rate was 1.77 um/min, selectivity was 91.23, trench CD loss was about -0.2um, the etching morphology was positive profile and nearly vertical. At the same time, the dry cleaning process was studied to solve the grass problem while providing a method for the maintenance of deep reactive ion etching process.