| 摘要 |
PURPOSE:To improve the step coverage of a wiring material by a method wherein the taper angle of a masking material spread on a multilayer insulating film is controlled and the taper angle of an upper insulating film is controlled by the selection ratios of the masking material and the multilayer insulating film. CONSTITUTION:A lower insulating film (plasma CVD Si nitride film) 5 is formed on a semiconductor substrate 1 and an upper insulating film (polyimide resin film) 6 is formed thereon. An etching masking material 7 (photo resist) is spread on the film 6. An opening is formed in the material 7 at an angle of inclination, which is an acute angle smaller than 90 degrees, of the wall surface of the opening. The film 6 is subjected to reactive ion etching at a selected etching rate ratio using the material 7 as a mask. The film 5 is subjected to reactive ion etching at a selected etching rate ratio using the film 6 as a mask. Thereby, the step coverage of a wiring material is improved.
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