A copper film vapor phase deposition method includes the steps of exposing high-purity copper to a plasma of a gas containing chlorine gas to etch the high-purity copper, thereby generating active CuxCly, wherein x is 1 to 3, y is 1 to 3, gas, and forming a copper film by transporting the CuxCly gas onto the surface of a substrate to be processed. An example digital-to-analog converter circuit includes a reference scaling circuit coupled to receive a first reference current. This, in turn, consumes more power than if such duty cycles could be predicted, which would allow for their smoothing. Through holes 14 are selectively utilized during formation of the desired circuit pattern upon insulation film 10 according to size of the manufactured semiconductor package.