Low Contact Resistance, Self-Aligned Metal Stud Process
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
A process is described for making low resistance metal interconnections (studs) through via holes in insulator films of varying thickness. The process requires no masking steps and is performed in situ in a single "deposition and etch" tool. The top surface of the stud is very nearly co-planar with the insulator surface, regardless of the insulator film thickness. Since the top surface of the studs is metal silicide or silicon dioxide, contact resistance to a next level of standard metal wiring, e.g., aluminum (Al) or aluminum alloys, is minimized by standard Al predeposition removal of the silicon dioxide that forms. Metal oxides are created if the metal films (deposited at > than oxidation temperature) are exposed to air while hot.