Abstract Gas chemistry has a significant impact on etch selectivity in semiconductor device fabrication, which is important for realization of atomic-scale removal and formation of high-aspect ratio features. To widen the controllable changes in the etchant composition in etching processes, our previous calculation showed the possibility of the controllable generation of CH2F and CHF2 related ions and radicals from a 1,1,2-trifluoroethane (CH2FCHF2) parent gas. The etch selectivity among silicon nitride (SiN), silicon dioxide (SiO2) and poly-Si films using CH2FCHF2 plasma mixed with O2 and Ar was investigated. The effects of the CH2FCHF2 and O2 partial pressures on the composition of CHF2+ and CH2F+ ions, which were measured with a quadrupole mass spectrometer, and on the possible reactions with respect to the CH2FCHF2 and O2 mixed gas phase were investigated using quantum chemical calculations. The etch selectivity was investigated through surface etching reactions for SiN, SiO2, and poly-Si films.

中文翻译：

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在氢氟乙烷化学中用 CH2FCHF2、O2 和 Ar 的混合物对 SiO2 和多晶硅薄膜选择性蚀刻 SiN

摘要 气体化学对半导体器件制造中的蚀刻选择性具有重要影响，这对于实现原子级去除和高深宽比特征的形成具有重要意义。为了扩大蚀刻过程中蚀刻剂成分的可控变化，我们之前的计算显示了从 1,1,2-三氟乙烷 (CH2FCHF2) 母气中可控生成 CH2F 和 CHF2 相关离子和自由基的可能性。研究了使用混合有 O2 和 Ar 的 CH2FCHF2 等离子体在氮化硅 (SiN)、二氧化硅 (SiO2) 和多晶硅薄膜之间的蚀刻选择性。CH2FCHF2 和 O2 分压对 CHF2+ 和 CH2F+ 离子组成的影响，用四极杆质谱仪测量，并使用量子化学计算研究了 CH2FCHF2 和 O2 混合气相的可能反应。通过对 SiN、SiO2 和多晶硅薄膜的表面蚀刻反应来研究蚀刻选择性。