| 摘要 |
PROBLEM TO BE SOLVED: To provide a plasma etching method by which the surface of polysilicon can be smoothed by plasma etching and satisfactory etching rate can be also ensured. SOLUTION: A plasma etching apparatus 1 has main etching operation and over-etching operation. The main etching operation is used to etch a polysilicon film by Cl<SB>2</SB>/SF<SB>6</SB>/N<SB>2</SB>plasma that is produced by exciting Cl<SB>2</SB>gas, SF<SB>6</SB>gas and N<SB>2</SB>gas, and the over-etching operation is used to etch a polysilicon film by Cl<SB>2</SB>/HBr/CF<SB>4</SB>plasma that is produced by exciting Cl<SB>2</SB>gas, HBr gas and CF<SB>4</SB>gas. During the main etching operation, the formation of unevenness on the surface of the polysilicon can be suppressed by adding the N<SB>2</SB>gas, and satisfactory etching rate can be ensured. COPYRIGHT: (C)2008,JPO&INPIT
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