| 摘要 |
PURPOSE:To prevent sharp edges from forming at corners of an upper portion and a bottom portion of an opening, by method in which, after films to be etched are formed on a semiconductor substrate and they are physically anisotropically etched to form an opening to such an extent that a thin layer can be left, the inside of the opening is isotropically etched using chemical etching until the thin layer disappears. CONSTITUTION:Formed on a semiconductor substrate 1 are a first film 5, for example a plasma SiO2 film, which has relatively small chemical etching rate, a second film 6 thereon, for example a plasma silicon nitride film which has a large chemical etching rate, and a resist pattern 3. The films in the opening 3a are dug with reactive ion-etching to such a depth that the thin layer 5a can be left, forming the opening 7 in the first film 5. Last, the inside of the opening 7 is etched, using chemical dry-etching which ends when the surface of the substrate is exposed to the opening 7. Since the wall or side wall face of the generated opening 7A has a vertical face and its upper and bottom corners have curved faces, sharp edges do not exist. |
