Chemical Vapor Deposition of Tungsten (CVD W) as Submicron Interconnection and Via Stud

Abstract

Blanket‐deposited CVD W has been developed and implemented in a 4‐Mbit DRAM and equivalent submicron VLSI technologies. CVD W was applied as contact stud, interconnect, and interlevel via stud. The technologies have been proven reliable under several reliability stress conditions. Major technical problems involved in CVD W processing, such as adhesion, contact resistance, etchability, and hole fill will be discussed. A novel technique that uses as a contact and adhesion layer will be presented. This technique has lead to the resolution of the above technical problems and significantly improved the manufacturability of blanket CVD W processes.