| 摘要 |
PURPOSE:To flatten an insulating film on the first-layer wiring, by applying resist, which has the approximately same etching rate as that of a liquid phase oxide film to a thickness so that etching starts at the upper edge of the step of the insulating film, and performing controlled etching of the resist and the insulating film. CONSTITUTION:An insulating film 12 is formed on a semiconductor substrate 11. On the insulating film 12, e.g. a first-layer wiring 13 of Al is formed. On the wiring 13, e.g., a PSG insulating film 14 having a thickness of 1.3mum is formed. Then a liquid phase oxide film 15 is formed by a conventional method. Resist 16 is applied thereon. The etching rate of the resist is the same as that of the liquid phase oxide film. The resist is applied to a thickness of 0.4mum or less so that the resist at an upper edge 16a becomes thin. By dry etching using Freon gas, controlled etching of the resist and the liquid phase oxide film is performed to a thickness of about 0.3mum. The thickness of the insulating film 14 is made to remain so that the function as the insulating film can be achieved. Then the bottom of the stepped part is filled with the liquid phase oxide film. Thereafter, e.g., a second-layer wiring 17 of Al is formed on the flattened insulating film. Therefore wire breakdown does not occur. |
