MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE:To form a contact hole which does not allow the dielectric strength of interlayer insulating film and has a high pattern size accuracy for tapered etching by using a first etching mask having a high etching characteristic and a second photo etching mask by the photo resist for an insulating film. CONSTITUTION:A polycrystalline silicon 13 which becomes a first etching mask is formed at the surface of interlayer insulating film 12 on semiconductor substrate 11. The anisotropic etching is carried out to the polycrystalline silicon 13 using a photo resist film 14 and a first etching mask is formed by the polycrystalline silicon 13. Thereafter, a second etching mask 15 having a contact window which is smaller than that of the first etching mask 13 is formed using the photo resist film. The tapered etching is carried out to such a pattern having the etching masks 13, 15 in such a double-layer structure using the plasma obtained by adding oxygen gas to the fluorine gas plasma. Thereafter, the first and the second etching masks 13, 15 are removed and a tapered contact hole 16 can be obtained. An electrode of aluminium film 17 is formed on such hole.