Patent Number: 6,309,964

Title: Method for forming a copper damascene structure over tungsten plugs with improved adhesion, oxidation resistance, and diffusion barrier properties using nitridation of the tungsten plug

Abstract: A method for forming a damascene structure over tungsten plugs using nitridation of said tungsten plugs to provide better oxidation resistance, better adhesion properties and better copper diffusion barrier proerties. The process begins by providing a substrate structure having at least one device layer thereon and having a first dielectric layer overlying the device layer. The dielectric layer has tungsten plugs therein providing a conductive path between the surface of the dielectric layer and the device layer. The tungsten plugs are nitriduzed to form a WN.sub.x layer on top of the tungsten plugs. A second dielectric layer is deposited over the WNx layer and the first dielectric layer. The second dielectric layer is patterned to form a trench in the second dielectric layer; whereby the WN.sub.x layer is exposed in the trench. A barrier layer is formed in the trench. A metal layer is formed over the barrier layer. The metal layer and the second dielectric layer are planarized to form a damascene structure.

Inventors: Tsai; Ming Hsing (Taipei, TW), Shue; Shaulin (Hsinchu, TW)

Assignee: Taiwan Semiconductor Manufacturing Company

International Classification: H01L 21/70 (20060101); H01L 21/768 (20060101); H01L 021/476 ()

Expiration Date: 10/30/2018