| 摘要 |
PURPOSE:To enable the even etching process to be performed to notably improving the etching speed ratio between a polycrystalline silicon film and a photoresist film by a method wherein the surface of polycrysstalline silicon film is evenly damaged by ion implanting process. CONSTITUTION:A thermal oxide film 2 is formed on the surface of a semiconductor substrate 1 further to deposit a polycrystalline silicon film 3 on the film 2. The overall surface of photoresist film patterns 4 and exposed polycrystalline film 3 is implanted with ion shower 5 by e.g. phosphorus ion implanting process meeting such requirements as an acceleration voltage of 50 Kev and a dosage of 5 X 10<15>ion/cm<2> to be dryetched after the ion implanting process is performed. Thus, the surface of polycrystalline silicon film 3 is bombarded with ions in the preceding process to form a damage layer in high etching speed. Besides, the photoresist film 4 is degenerated into a dryetching resistant material. Through these procedures, a deep damage layer is evenly formed on the surface of ion implanted polycrystalline silicon film to improve the evenness in etching speed of overall polycrystalline silicon film.
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