An aluminum wiring layer and a protective (and/or barrier) layer are formed by sputtering in the same vacuum sputtering chamber without breaking the vacuum between forming the layers; and a refractory metal, or a refractory metal silicide QSix, where Q is a refractory metal and x is between 0 and 2, is used as a protective layer, for an aluminum wiring containing an added element (e.g., Cu) to pre