| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for dry etching by which silicon can be dry- etched by using resist layers as masks and in which the occurrence of silicon residues due to watermarks can be prevented. SOLUTION: After a polysilicon layer 14 is formed on a semiconductor substrate 10 through a gate insulating film 12, an interlayer insulating film of silicon oxide, etc., is formed on the layer 14 and insulating films 16a and 16b are left by wet-etching the interlayer insulating film by using resist layers 18a and 18b as masks. When deionized water rinsing and drying are performed, water drops and watermarks 22 are left on the polysilicon layer 14. After the water drops are changed to watermarks 22a and 22b through heat treatment, the water marks 22, 22a, and 22b left on the layer 14 and a silicon oxide film naturally generated on the surface of the layer 14 are removed by dry etching. Thereafter, a gate electrode layer is obtained by patterning the layer 14 by dry etching by using the resist layers 18a and 18b as masks. The formation of the insulating films 16a and 16b can be omitted.
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