| 摘要 |
PROBLEM TO BE SOLVED: To form a semiconductor device provided with the plural kinds of gate insulation films by a simple method. SOLUTION: In this manufacturing method, after a first oxidized film is formed on a semiconductor substrate, the first oxidized film is selectively removed by the etching of two steps using liquid chemicals. Then, a second oxidized film is formed on the surface of the semiconductor substrate, from which the first oxidized film is removed in such a manner. In this case, by the etching of a first step, the first oxidized film is etched to a prescribed depth. Then, by the etching of a second step, the remaining first oxidized film is removed completely. In this case, the liquid chemical of the high etching speed of the first oxidized film is used in the etching of the first step, and the liquid chemical of a low etching speed is used in the etching of a second step.
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