Integration of ALD tantalum nitride and alpha-phase tantalum for copper metallization application

Abstract

A method for forming a metal interconnect on a substrate is provided. In one aspect, the method comprises depositing a refractory metal containing barrier layer having a thickness that exhibits a crystalline like structure and is sufficient to inhibit atomic migration on at least a portion of a metal layer by alternately introducing one or more pulses of a metal-containing compound and one or more pulses of a nitrogen-containing compound; depositing a seed layer on at least a portion of the barrier layer; and depositing a second metal layer on at least a portion of the seed layer.

Description

[0001] This application claims benefit of U.S. Provisional Patent Application Serial No. 60 / 346,086, filed on Oct. 26, 2001, and entitled "Method and Apparatus for ALD Deposition", which is incorporated by reference herein. This application also claims benefit of U.S. patent application, Ser. No. 09 / 965,370, filed on Sep. 26, 2001, and entitled "Integration of Barrier Layer and Seed Layer", which is incorporated by reference herein. This application also claims benefit of U.S. patent application Ser. No. 09 / 965,373, filed on Sep. 26, 2001, and entitled "Integration of Barrier Layer and Seed Layer", which is incorporated by reference herein. This application further claims benefit of U.S. patent application Ser. No. 09 / 965,369, filed on Sep. 26, 2001, and entitled "Integration of Barrier Layer and Seed Layer", which is incorporated by reference herein. This application further claims benefit of U.S. patent application Ser. No. 10 / 193,333, filed on Jul. 10, 2002, and entitled "Integra...

AI Technical Summary

Problems solved by technology

However, copper diffuses more readily into surrounding materials and can alter the electronic device characteristics of the adjacent layers and, for example, form a conductive path between layers, thereby reducing the reliability of the overall circuit and possibly resulting in device failure.

Therefore, the additional amount of the barrier layer on the bottom of the feature not only increases the overall resistance of the feature, but also forms an obstruction between higher and lower metal interconnects of a multi-layered interconnect structure.

It is believed that the surface attraction used to physisorb, adsorb, absorb, or chemisorb a monolayer of reactants on a substrate surface are self-limiting in that only one monolayer may be deposited onto the substrate surface during a given pulse because the substrate surface has a finite number of sites available for the reactants.

While not wishing to be bound by theory, it is believed that a plasma treatment of a tantalum nitride film, for example, reduces the nitrogen content of one or more sublayers by sputtering off nitrogen, which in turn reduces resistivity.

It can be appreciated that a margin of error is present with this kind of measurement technique as well as any other measurement technique for determining a thickness of a deposited layer.

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