Patent ID: 7087534

Claim:
A semiconductor die, comprising: an integrated circuit supported by a base layer and having a plurality of integrated circuit devices, wherein at least one of the plurality of integrated circuit devices has a semiconductor structure formed by a method comprising: forming an insulator layer on the base layer, wherein the insulator layer has a surface; patterning the insulator layer to define a hole, wherein the hole has sidewalls defined by the insulator layer and a bottom defined by an exposed portion of the base layer; forming a titanium layer overlying the surface of the insulator layer and the sidewalls and bottom of the hole by chemical vapor deposition; forming a titanium nitride layer overlying the titanium layer by chemical vapor deposition; forming a tungsten layer overlying the titanium nitride layer and filling the hole; removing a portion of the tungsten layer overlying the surface of the insulator layer; and removing a portion of the titanium and titanium nitride layers overlying the surface of the insulator layer subsequent to removing the portion of the tungsten layer by exposing the portion of the titanium and titanium nitride layers to a sulfuric acid solution.