a sample structure a homogeneous alloy comprising al 1 5 wt cu 0 63 wt w resulted in 3 94 micro ohm centimeter resistivity which compares favorably with 3 39 micro ohm centimeter resistivity without any tungsten lower tungsten content lowers resistivity of the alloy further the alloy metallization in accordance with the present invention can be applied by conventional metal deposition techniques such as sputtering evaporation or the like a compatible deposition method is shown in u s pat no 4 970 176 issued to tracy et al on nov 30 1990 and incorporated herein by reference the preferred method of applying the metallization in accordance with the present invention is sputtering sputter targets are manufactured comprising a homogeneous al cu w alloy the metallization is applied to a semiconductor substrate having integrated circuitry formed therein by sputtering the metal from the target onto the substrate the deposition step is followed by a conventional photoresist patterning and metal etch process in an alternative embodiment a homogeneous aluminum copper alloy is deposited as a separate layer from the tungsten a tungsten layer can be formed above below or as an intermediate layer with an aluminum metallization the tungsten layer is preferably a few hundred angstroms thick the aluminum copper layer and the tungsten layer are heated causing the tungsten to diffuse into the aluminum copper alloy to provide the aluminum copper tungsten alloy in accordance with the present invention because this second embodiment requires multiple depositions and multiple sputter targets in most applications it is preferred to use a single al cu w homogeneous alloy.