The method involves forming a wiring layer (30) on a substrate. A second wiring layer (31) is formed which has a higher definition than an insulating film (32). A conductive layer is applied on the first layer. An insulating layer is formed on the second layer. The film is then selectively etched to form a contact opening (33) which reveals the surface of the second layer. A third wiring layer (34) is formed in the contact opening on the second layer. Preferably the second layer is 10 per cent smaller than the first. The second wiring layer contains a metal on which no surface oxide film forms at normal temperatures.
