Cobalt first layer advanced metallization for interconnects

• US 10,163,793 B2
• Filed: 11/07/2017
• Issued: 12/25/2018
• 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:
  US15/806,314
• Publication Number:
  US 20180061703A1
• Time in Patent Office: 413 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 21/76802 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 21/76855 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 21/76858 by diffusing alloying elements
• CPC Class Codes: H01L 21/76864 Thermal treatment
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• 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 23/53247 : Noble-metal alloys
• 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
• CPC Class Codes: H01L 23/53266 : Additional layers associated with refractory-metal layers, e.g. adhesion, barrier, cladding layers

Abstract

An integrated circuit device has a substrate including a dielectric layer patterned with a pattern which includes a set of features in the dielectric for a set of metal conductor structures. An adhesion promoting layer is disposed on the set of features in the patterned dielectric. A ruthenium layer is disposed on the adhesion promoting layer. A cobalt layer is disposed on the ruthenium layer filling a first portion of the set of features. The cobalt layer has a u-shaped cross section having a thicker bottom layer than side layers. The cobalt layer is formed using a physical vapor deposition process. A metal layer is disposed on the cobalt layer filling a second, remainder portion of the set of features.

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 ruthenium layer disposed on the adhesion promoting layer;

a cobalt layer having a u-shaped cross section having a thicker bottom layer than side layers disposed on the ruthenium layer filling a first portion of the set of features, wherein the cobalt layer is formed using a physical vapor deposition process;

a second metal layer disposed on the cobalt layer filling a second, remainder portion of the set of features; and

wherein a thickness of the reflowed cobalt layer from the ruthenium layer to a bottom of the second metal layer and a thickness of the second metal layer after planarization are substantially equal.

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, further comprising a RuCo alloy layer disposed between the ruthenium layer and the cobalt layer.

10. The device as recited in claim 1, wherein the metal layer disposed on the cobalt layer is copper.

11. The device as recited in claim 1, wherein the metal layer is selected from the group consisting of Ni, Ir and Rh.

12. The device as recited in claim 1, wherein the respective thicknesses of the reflowed cobalt layer and the second metal layer are formed according to a desired resistivity and reliability needed for the device.

13. The device as recited in claim 1, wherein a first dimension of each of the metal conductor structures is less than twenty nanometers.