Patent ID: 6887353

Claim:
A method of producing a copper interconnect structure comprising a combined TaN x /Ta barrier layer and wetting layer, and an overlying copper layer, wherein the Cu <111> crystallographic content of said overlying copper layer is at least 70% of the Cu <111> crystallographic content which can be obtained by depositing said copper layer over a pure Ta barrier layer which is about 500 â„« thick, said method comprising the steps of: a) depositing a first layer of TaN x having a thickness ranging from greater than about 50 â„« to about 1,000 â„«; b) depositing a second layer of Ta having a thickness ranging from about 5 â„« to about 500 â„« over the surface of said first layer of TaN x ; and c) depositing a third layer of copper over the surface of said second layer of Ta, wherein at least a portion of said third layer of copper is deposited using a physical vapor deposition technique, and wherein the substrate temperature at which said third layer of copper is deposited is less than about 500Â° C.