Process Resulting in Increased Contact Area Refractory Metal Stud to Aluminum Wiring
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
A novel process sequence is described for creating a refractory metal stud to connect underlying conductive regions to an upper level of aluminum alloy wiring. The interface (contact) area between the refractory metal and the aluminum alloy wiring is a function of wiring metal thickness t and a linear function of metal stud (or via hole) radius r. In an environment of increasing wiring density where via holes must decrease in radius r and where thickness t is constant or increasing, the area of contact between the stud and the metal line is higher in this process than in processes which make this contact area a function of r2 . This advantage may be used in a trade-off between achieving a lower contact resistance or permitting larger alignment tolerance in aligning the wiring mask to studs.