Patent ID: 7863179

Claim:
A method of depositing a metallic barrier layer to line an etched interconnect structure in an atomic layer deposition system, comprising: depositing the metallic barrier layer to line the etched interconnect structure using atomic layer deposition, the etched interconnect structure being etched into a dielectric layer, wherein a nitrogen concentration of the metallic barrier layer decreases with an increasing film thickness, and wherein the nitrogen concentration of the metallic barrier layer is changed by varying a chemical composition of one or more process gases in a sequential pulsing of process gases, by varying durations of the sequential pulsing of process gases, or a combination of both, such that the nitrogen concentration of the metallic barrier layer is highest where the metallic barrier layer is in contact with the dielectric layer; and forming a copper layer over the metallic barrier layer, such that the nitrogen concentration of the metallic barrier layer is lowest where the metallic barrier layer is in contact with the copper layer.