Sequential cyclic etching of copper thin films was performed using HBr/Ar gas and Ar plasma. The first step involved the formation of CuBr_x layers by exposing copper thin films to HBr/Ar gas, and the second step involved the removal of the CuBr_x layers by Ar ion sputtering. HBr/Ar gas was used to form the CuBr_x layers, and the growth of CuBr_x layers could be saturated under certain conditions. Ar ion sputtering was optimized under the condition that led to the removal of the CuBr_x layer and prevented the copper sputtering. The formation and removal of the CuBr_x layers were confirmed by x-ray photoelectron spectroscopy analysis. The etch depth per cycle was estimated to be approximately 1.2 nm. The 120-cycle etching of copper films patterned with an SiO₂ hard mask exhibited good etch profiles without any redepositions or etch residues. The cyclic etching of copper thin films using HBr/Ar gas was proposed as a promising etching technique.

中文翻译：

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使用HBr和Ar气体循环蚀刻铜薄膜

使用HBr / Ar气体和Ar等离子体对铜薄膜进行顺序循环蚀刻。第一步涉及通过将铜薄膜暴露于HBr / Ar气体来形成CuBr _x层，第二步涉及通过Ar离子溅射去除CuBr _x层。使用HBr / Ar气体形成CuBr _x层，并且在某些条件下CuBr _x层的生长可以饱和。在导致去除CuBr _x层并防止铜溅射的条件下优化了Ar离子溅射。CuBr _x的形成和去除通过X射线光电子能谱分析确认了层。估计每个周期的蚀刻深度约为1.2 nm。用SiO ₂硬掩模图案化的铜膜的120周期蚀刻显示出良好的蚀刻轮廓，没有任何再沉积或蚀刻残留物。提出了使用HBr / Ar气体对铜薄膜进行循环刻蚀作为一种有前途的刻蚀技术。