Nitridized ruthenium layer for formation of cobalt interconnects

• US 9,941,213 B2
• Filed: 01/23/2017
• Issued: 04/10/2018
• Est. Priority Date: 08/17/2016
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Edelstein, Daniel C, Yang, Chih-Chao
• Primary Examiner(s): Page, Dale E
• Assistant Examiner(s): Haider, Wasiul
• Application Number:
  US15/413,367
• Publication Number:
  US 20180053726A1
• Time in Patent Office: 442 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 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 21/76816 Aspects relating to the layout of the pattern or to the size of vias or trenches layout of the interconnections per se H01L23/528; CAD of ICs G06F30/00
• 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 21/76855 After-treatment introducing at least one additional element into the layer
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 21/76882 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 23/53238 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 23/53266 Additional layers associated with refractory-metal layers, e.g. adhesion, barrier, cladding layers

Abstract

An advanced metal conductor structure is described. An integrated circuit device including a substrate having a dielectric layer is patterned. 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 nitridized ruthenium layer is disposed over the adhesion promoting layer. A cobalt layer disposed over the nitridized ruthenium layer filling the set of features, wherein 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 on the set of features in the patterned dielectric;

a nitridized ruthenium layer disposed on the adhesion promoting layer; and

a cobalt layer disposed on the nitridized ruthenium layer filling a remainder of the set of features, wherein the cobalt layer is completely 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 formed in the patterned dielectric 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 formed in the patterned dielectric 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 damascene pattern 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 vias.

9. The device as recited in claim 1, wherein a dimension of the set of metal conductor structures is less than 30 nm wherein the overall resistivity of Co is lower than the overall resistivity of Cu so that the RC-delay is reduced.

10. The device as recited in claim 1, wherein the patterned dielectric structure is a combination of a set of vias and a set of trenches.

11. The device as recited in claim 1, wherein a thickness of the ruthenium layer is in the range of 2 nm to 20 nm.

12. The device as recited in claim 1, wherein the adhesion promoting layer is a nitrogen enriched layer formed in the patterned dielectric layer produced by a nitridation process, and wherein an unnitridized portion of the ruthenium metal layer is bonded to the nitrogen enriched layer formed in the patterned dielectric layer.

13. The device as recited in claim 1, wherein the ruthenium metal layer is a fully nitridized ruthenium layer disposed on and bonded to the adhesion promoting layer.

14. The device as recited in claim 1, wherein a first dimension of the advanced connector structure is less than twenty nanometers.