| 摘要 |
PURPOSE:To prevent an Si substrate and an isolation oxide film from damaging due to an etching by horizontally etching the sidewall of a conductive film which becomes an electrode to form the electrode. CONSTITUTION:An SiO2 film 12 is formed on a P-type Si substrate 11, a polycrystalline Si film 13 is grown thereon, and a photoresist pattern is formed on the film 13. Then, the film 13 is selectively removed by dry etching to form an electrode. Thereafter, a high concentration N-type impurity layer 15 is formed on an Si substrate part corresponding to the part from which the film 13 is removed. Then, the sidewall of the film 13 is etched with mixture solution of fluoric acid and nitric acid to form a desired electrode. Subsequently, after a pattern 14 is removed, a low concentration N-type impurity layer 16 is formed on the substrate 11 of the part from which the sidewall of the film 13 is removed by etching. According to the manufacture, since damages due to the etching of the substrate and the isolation oxide film are eliminated, it can prevent the characteristics of the low concentration drain structure MOS transistor from deteriorating or isolation breakdown strength from decreasing.
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