| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, since the SF<SB>6</SB>/O<SB>2</SB>used for etching a gate electrode to have a tapered shape is inferior in the selection ratio between an electrode material layer and a gate insulating film underlying the layer, even the gate insulating film is etched and, as a result, the remaining film amount of the insulating film fluctuates and the operating characteristic of a manufactured thin film transistor is not stablized. SOLUTION: After an electrode material is laminated in Fig (c), a gate material 25 is etched to the moment immediately before the gate insulating film underlying the material is exposed by using the SF<SB>6</SB>/O<SB>2</SB>as an etching gas. Successively in Fig(d), the remaining electrode material layer 25 is etched by ashing a resist 10 by using Cl<SB>2</SB>/O<SB>2</SB>having a better selection ratio as an etching gas. Through these two etching steps, the gate electrode 5 having a desired tapered shape can be formed. COPYRIGHT: (C)2004,JPO
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