PURPOSE: To provide a semiconductor device manufacturing method b which an increase in contact resistance can be prevented in laminated wiring by preventing the occurrence of mutual diffusion between an aluminum or aluminum alloy layer and reflection preventing film and the reliability of aluminum or aluminum alloy wiring can be improved in conjunction with the improvement of a method for forming wiring of aluminum or an aluminum alloy.

CONSTITUTION: In this semiconductor device manufacturing method including a process in which wiring is formed by successively forming an aluminum or aluminum alloy layer 2 and reflection preventing film 4 on a substrate 1 and patterning the laminated body of the layer 2 and film 4, an aluminum or aluminum-alloy oxide film 3 is formed to a thickness of 20-50 between the layer 2 and film 4.