Plasma etching method using gas molecule containing sulfur atom

• Main Authors: Kato, Korehito, Shimoda, Mitsuharu, Iketani, Yoshihiko, Takahashi, Yoshinao
• Format: Patent
• Language: English
• Published: 26.04.2022
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

Provided is a plasma etching method that enables, in a semiconductor fabrication process, selective processing of a film consisting of a single material, such as SiO2 or SiN, or a composite material of SiO2 and SiN over a mask material as well as processing into satisfactorily vertical processed shapes.It is possible, for example, to enhance selectivity over a mask material or other materials excluding an etching target, to reduce damage on sidewalls, and to suppress etching in the lateral direction by generating a plasma of a gas compound having a thioether skeleton represented by general formula (1) or a mixed gas thereof and etching a film consisting of a composite material or a single material, such as SiO2 or SiN, thereby depositing a protective film that contains sulfur atoms and has a lower content of fluorine atoms than the cases of using common hydrofluorocarbon gases:general formula (1): Rf1-S-Rf2  (1)where Rf1 is a monovalent organic group represented by CxHyFz and Rf2 is a monovalent organic group represented by CaHbFc.