| 摘要 |
PURPOSE:To prevent breaking of metal wiring, by a method wherein an insulation film of two layers being different in etching rate is used and an opening with tapered portion is formed. CONSTITUTION:A first oxide film 12 is formed on main surface of a solicon substrate 11 by thermal oxidation process, and a second oxide film 13 is formed on the first oxide film 12 by CVD. Etching is performed using a photo mask 20, and an opening 14 with tapered portion is formed on the oxide film 12 according to difference of etching rate between both oxide films 12, 13. After removing the mask 20, a third oxide film 15 is formed by CVD. The oxide film 15 is etched using a photo mask, and an opening 16 is formed within the opening 14. A metal wiring 17 is formed, and breaking is prevented by the tapered portion of the first oxide film 12 and covering of edge of the second oxide film 13 with the third oxide film 15. |
