Silicon dioxide (SiO₂) layers using photoresist (PR) masks are etched by inductively coupled plasma in CH₄/SF₆ under various etching conditions. A thin CH_x F_y polymer layer which exists on the surface of sample during steady‐state etching is observed. The steady‐state CH_x F_y layer reduces the physical sputtering of ions, resulting in the etching rate of PR decreases significantly. Although the high‐density plasmas can enhance the physical sputtering to some extent and give SiO₂ more opportunities to react with fluorine atoms, it is helpful to improve the etching rate of SiO₂. By optimizing process conditions, the thickness of the steady‐state CH_x F_y layer and the density of ions are regulated, and a reasonable selective etching is obtained.

中文翻译：

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CH4 / SF6等离子刻蚀SiO2的研究

在各种蚀刻条件下，使用光致抗蚀剂（PR）掩模的二氧化硅（SiO ₂）层在CH ₄ / SF _6中通过电感耦合等离子体进行蚀刻。观察到在稳态蚀刻期间样品表面上存在薄的CH _x F _y聚合物层。稳态CH _x F _y层减少了离子的物理溅射，导致PR的蚀刻速率大大降低。尽管高密度等离子体可以在某种程度上增强物理溅射性能，并使SiO ₂具有更多与氟原子反应的机会，但有助于提高SiO ₂的刻蚀速率。通过优化工艺条件，可以调节稳态CH _x F _y层的厚度和离子密度，从而获得合理的选择性蚀刻。