Copper alloys for interconnections having improved electromigration characteristics and methods of making same
First Claim
1. A method of forming a Cu alloy, comprising:
- depositing a seed layer on a substrate, the seed layer comprising Cu and at least one first doping element;
forming a capping layer over the seed layer, wherein the seed layer and the capping layer are formed sequentially and without exposing the seed layer to an atmosphere prior to deposition of the capping layer;
forming a layer of Cu over the capping layer;
driving the at least one doping element from the seed layer into the Cu layer;
forming a dopant layer having a second doping element over said layer of Cu and driving said second doping element into said layer of Cu.
0 Assignments
0 Petitions
Accused Products
Abstract
Formation of copper alloy interconnect lines on integrated circuits includes introducing dopant elements into a copper layer. Copper alloy interconnect lines may be formed by providing a doping layer over a copper layer, driving dopant material into the copper layer with a high temperature step, and polishing the copper layer to form individual lines. Copper alloy interconnect lines may be formed by implanting dopants into individual lines. Copper alloy interconnect lines may be formed by providing a doped seed layer with a capping layer to prevent premature oxidation, forming an overlying copper layer, driving in the dopants, and polishing to form individual lines. In this way, electromigration resistance and adhesion characteristics may be improved by having relatively higher doping concentrations at outer portions of an interconnect line while the desired low electrical resistivity of the interconnect is maintained by keeping the interior portions of the interconnect with a substantially lower doping concentration.
31 Citations
13 Claims
-
1. A method of forming a Cu alloy, comprising:
-
depositing a seed layer on a substrate, the seed layer comprising Cu and at least one first doping element; forming a capping layer over the seed layer, wherein the seed layer and the capping layer are formed sequentially and without exposing the seed layer to an atmosphere prior to deposition of the capping layer; forming a layer of Cu over the capping layer; driving the at least one doping element from the seed layer into the Cu layer;
forming a dopant layer having a second doping element over said layer of Cu and driving said second doping element into said layer of Cu. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification