| 摘要 |
Because of environmental pollution prevention laws, PFC (perfluorocarbon) and HFC (hydrofluorocarbon), both etching gases for silicon oxide and silicon nitride films, are expected to be subjected to limited use or become difficult to obtain in the future. To accommodate such a problem, an etching gas containing fluorine atoms is introduced into a plasma chamber. In a region where plasma etching takes place, the fluorine-containing gas plasma is made to react with solid-state carbon in order to produce a molecular chemical species such as CF4, CF2, CF3 and C2F4 for etching. This method assures a high etching rate and high selectivity while keeping a process window wide.
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