MULTIPLE PRE-CLEAN PROCESSES FOR INTERCONNECT FABRICATION

• US 20170092538A1
• Filed: 12/11/2015
• Published: 03/30/2017
• Est. Priority Date: 09/24/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Spooner, Terry A., Wang, Wei, Yang, Chih-Chao
• Granted Patent: US 9,831,182 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/3115 Doping the insulating layers
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/76805 the opening being a via or contact hole penetrating the underlying conductor
• 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 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76883 Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53295 Stacked insulating layers

Abstract

A method of making an interconnect structure includes forming an opening within a dielectric material layer disposed on a substrate including a conductive material, the opening extending from a first surface to a second surface of the dielectric material layer and being in contact with a portion of the substrate; performing a plasma treatment process to chemically enrich exposed surfaces of the dielectric material that line the opening to form a chemically-enriched dielectric surface layer that included an element in a higher concentration than a remaining portion of the dielectric material layer; performing a chemical treatment process to remove a metal contact product from the portion of the substrate that is in contact with the opening; and disposing a conductive material in the opening to substantially fill the opening and form the interconnect structure.

Claims

1. A method of making an interconnect structure, the method comprising:

forming an opening within a dielectric material layer disposed on a conductive substrate, the opening extending from a first surface to a second surface of the dielectric material layer and being in contact with a portion of the conductive substrate;

performing a plasma treatment process to chemically enrich exposed surfaces of the dielectric material that line the opening to form a chemically-enriched dielectric surface layer that comprises an element in a higher concentration than a remaining portion of the dielectric material layer;

performing a chemical treatment process, after performing the plasma treatment process, to remove a metal contact product from the portion of the conductive substrate that is in contact with the opening;

disposing a metal diffusion barrier liner in the opening and directly on the conductive substrate; and

disposing a conductive material on the metal diffusion barrier liner to substantially fill the opening and form the interconnect structure.

2. The method of claim 1, wherein the plasma treatment process comprises reacting a surface of the dielectric material layer with a plasma comprising silicon, nitrogen, phosphorus, oxygen, or any combination thereof.

3. The method of claim 1, wherein the element in the higher concentration in the chemically-enriched dielectric surface layer is silicon, nitrogen, phosphorus, oxygen, or any combination thereof.

4. The method of claim 1, wherein the plasma treatment process comprises employing a current density in a range from about 100 to about 5,000 μ

A/cm².

5. The method of claim 1, wherein the chemical treatment process comprises employing a current density in a range from about 5 to about 20 μ

A/cm² to remove copper compounds.

6. The method of claim 1, wherein the metal contact product comprises a copper compound.

7. A method of making an interconnect structure, the method comprising:

forming an opening within a dielectric material layer disposed on a conductive substrate, the opening extending from a first surface to a second surface of the dielectric material layer and being in contact with a portion of the conductive substrate;

performing a first plasma treatment process to chemically enrich exposed surfaces of the dielectric material that line the opening to form a chemically-enriched dielectric surface layer that comprises an element in a higher concentration than a remaining portion of the dielectric material layer;

performing a second plasma treatment process, after performing the first plasma treatment process, to remove a metal contact product from the portion of the conductive substrate that is in contact with the opening;

disposing a metal diffusion barrier liner in the opening and directly on the conductive substrate;

disposing a conductive material on the metal diffusion barrier liner in the opening to fill the opening; and

performing a planarization process to form the interconnect structure.

8. The method of claim 7, wherein the second plasma treatment process comprises reacting the portion of the substrate that is in contact with the opening with a plasma comprising H₂ or He.

9. The method of claim 7, wherein the metal contact product comprises copper and silicon, nitrogen, phosphorus, oxygen, or any combination thereof.

10. The method of claim 7, wherein the first plasma treatment process employs a current density in a range from about 500 to about 2,000 μ

A/cm².

11. The method of claim 7, wherein the chemically-enriched dielectric surface layer has a thickness in a range from about 50 to about 200 nm.