基于水平集方法的离子束刻蚀碲镉汞的轮廓演变模拟

Simulation of profile evolution in HgCdTe ion beam etching by the level set method

用水平集方法建立了碲镉汞的离子束刻蚀轮廓的数值模型模型的输入参数包括掩膜厚度、掩膜侧壁倾角、掩膜沟槽宽度、离子束散角、刻蚀速度等参数.对碲镉汞的刻蚀轮廓和刻蚀速度减缓现象进行了模拟和实验验证结果表明在沟槽宽度为4~10μm的范围内计算得到的刻蚀深度和SEM测量结果相差6~20%.对掩膜的轮廓演变进行了模拟给出了一个优化设计掩膜厚度来提高深宽比的实例.

A numerical model was established by the level set method to simulate the etching profile evolution in HgCdTe ion beam etching. The input parameters are: mask thickness,the slope of mask sidewall, trench width,ion angular distributions,etching speed,et al. Etching lag and etching profile of HgCdTe were simulated and compared with the experimental results. The results show that,given nominal trench width 4 ~ 10 μm,the errors between simulated etch depths and that of the experiments are 6 ~ 20%. The profile evolution of etching mask was simulated and an example was given to illustrate how to design the mask thickness to improve the aspect ratio.