Cobalt top layer advanced metallization for interconnects

• US 9,859,433 B1
• Filed: 01/23/2017
• Issued: 01/02/2018
• Est. Priority Date: 08/17/2016
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Edelstein, Daniel C, Yang, Chih-Chao
• Primary Examiner(s): Stark, Jarrett
• Application Number:
  US15/413,381
• Time in Patent Office: 344 Days
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/76814 post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors
• CPC Class Codes: H01L 21/76826 by contacting the layer with gases, liquids or plasmas
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/7684 Smoothing; Planarisation
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76847 the layer being positioned within the main fill metal
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/7685 the layer covering a conductive structure H01L21/76849 takes precedence
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76858 by diffusing alloying elements
• CPC Class Codes: H01L 21/76882 Reflowing or applying of pressure to better fill the contact hole
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/528 Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• CPC Class Codes: H01L 23/53209 based on metals, e.g. alloys, metal silicides H01L23/53285 takes precedence
• CPC Class Codes: H01L 23/53223 Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53252 : Additional layers associated with noble-metal layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53261 : Refractory-metal alloys

Abstract

An advanced metal conductor structure is described. An integrated circuit device including a substrate having a patterned dielectric layer. The pattern includes a set of features in the dielectric for a set of metal conductor structures. An adhesion promoting layer is disposed over the set of features in the patterned dielectric. A metal layer fills a first portion of the set of features and is disposed over the adhesion promoting layer. A ruthenium layer is disposed over the metal layer. A cobalt layer is disposed over the ruthenium layer fills a second portion of the set of features. The cobalt layer is formed using a physical vapor deposition process.

Claims

1. An integrated circuit device comprising:

a substrate including a dielectric layer patterned with a pattern includes a set of features in the dielectric for a set of metal conductor structures;

an adhesion promoting layer disposed over the set of features in the patterned dielectric;

a metal layer filling a first portion of the set of features disposed over the adhesion promoting layer;

a ruthenium layer disposed over the metal layer;

a nitrogen enriched surface layer on the ruthenium layer; and

a cobalt layer disposed over the nitrogen enriched surface layer on the ruthenium layer filling a second portion of the set of features, wherein the cobalt layer is formed using a physical vapor deposition process.

2. The device as recited in claim 1, wherein the adhesion promoting layer is a liner layer.

3. The device as recited in claim 1, wherein the adhesion promoting layer is a nitrogen enriched layer produced by a nitridation process.

4. The device as recited in claim 1, wherein the adhesion promoting layer is comprised of a nitrogen enriched layer produced by a nitridation process and a liner layer comprised of one or more materials selected from the group consisting of Ta, Ti, W, TaN, TiN and WN.

5. The device as recited in claim 1, wherein the set of metal conductor structures are a set of conductive lines.

6. The device as recited in claim 1, wherein the metal fill in the set of conductive lines trenches is coplanar with a top surface of the dielectric in field areas of the dielectric layer.

7. The device as recited in claim 1, wherein the set of metal conductor structures are a set of conductive vias.

8. The device as recited in claim 1, wherein the set of metal conductor structures are a set of conductive lines and a set of vias.

9. The device as recited in claim 1, wherein the set of features have a first dimension of less than twenty nanometers.

10. The device as recited in claim 1, wherein first metal layer has a thickness in the range of 2 nm to 20 nm and the thickness of the Co layer has a thickness in the range of 25 nm to 100 nm.