US 11,990,368 B2
Doped selective metal caps to improve copper electromigration with ruthenium liner
Mehul B. Naik, San Jose, CA (US); and Zhiyuan Wu, San Jose, CA (US)
Assigned to Applied Materials, Inc., Santa Clara, CA (US)
Filed by Applied Materials, Inc., Santa Clara, CA (US)
Filed on Jun. 23, 2022, as Appl. No. 17/848,162.
Application 17/848,162 is a division of application No. 15/722,639, filed on Oct. 2, 2017, granted, now 11,373,903.
Claims priority of provisional application 62/403,186, filed on Oct. 2, 2016.
Prior Publication US 2022/0336271 A1, Oct. 20, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 21/768 (2006.01); H01L 21/285 (2006.01); H01L 23/532 (2006.01)
CPC H01L 21/76849 (2013.01) [H01L 21/28562 (2013.01); H01L 21/76846 (2013.01); H01L 21/76858 (2013.01); H01L 21/76864 (2013.01); H01L 21/76873 (2013.01); H01L 21/76879 (2013.01); H01L 21/76882 (2013.01); H01L 21/76883 (2013.01); H01L 23/53233 (2013.01); H01L 23/53238 (2013.01); H01L 23/53266 (2013.01); H01L 2221/1089 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for forming a structure in a substrate, comprising:
forming a barrier layer on exposed surfaces of a feature in a dielectric layer of the substrate;
forming a liner layer on the barrier layer, the liner layer comprising Ru, Pt, Pd, Os, or Ni material, wherein the Ru, Pt, Pd, Os, or Ni material of the liner layer is not present in the barrier layer;
forming a seed layer on the liner layer;
forming a metal fill on the seed layer by a metal fill process and overburdening the feature using an electroplating process;
performing a planarization process to expose a top surface of the dielectric layer; and
selectively forming a cobalt-aluminum alloy cap layer having a first cap layer of cobalt and a second cap layer of cobalt-aluminum alloy, the cobalt-aluminum alloy cap layer formed on the barrier layer, the liner layer, the seed layer, and the metal fill by exposing the substrate to a cobalt-containing precursor for forming the first cap layer and then an aluminum-containing precursor for forming the second cap layer, wherein the cobalt-aluminum alloy cap layer extends onto the liner layer.
 
9. A method for forming a structure in a substrate, comprising:
forming a barrier layer on exposed surfaces of a feature in a dielectric layer of the substrate;
forming an Ru liner layer on the barrier layer, wherein Ru is not present in the barrier layer;
forming a copper containing seed layer on the liner layer;
forming a metal fill on the seed layer by a metal fill process and overburdening the feature using an electroplating process;
performing a planarization process to expose a top surface of the dielectric layer; and
selectively forming a cobalt-aluminum alloy cap layer on the barrier layer, the liner layer, the seed layer, and the metal fill by exposing the substrate to a cobalt-containing precursor for forming a first layer of cobalt and an aluminum-containing precursor for forming a second layer of cobalt-aluminum alloy, wherein the cobalt-aluminum alloy cap layer extends onto the liner layer, wherein the substrate is exposed to the aluminum-containing precursor and the cobalt-containing precursor in an alternating manner or at the same time until a desired thickness of the cobalt-aluminum alloy cap layer is reached.