Chemical-mechanical planarization of barriers or liners for copper metallurgy

• US 6,743,268 B2
• Filed: 01/18/2002
• Issued: 06/01/2004
• Est. Priority Date: 05/07/1999
• Status: Active Grant

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Lustig, Naftali E., Edelstein, Daniel C., Cote, William J.
• Primary Examiner(s): MARCHESCHI, MICHAEL A
• Application Number:
  US10/051,135
• Publication Number:
  US 20020066234A1
• Time in Patent Office: 865 Days
• Field of Search: 513/07, 513/08, 513/09, 106/3, 438/692, 438/693, 438/691, 438/622, 438/631, 438/633, 438/734, 438/627, 438/687, 438/648, 438/656, 438/643, 438/645, 438/653, 438/669, 438/672, 438/685, 216/105, 216/89, 252/79.1
• US Class Current: 51/308
• CPC Class Codes: C09G 1/02 containing abrasives or grinding agents abrasives as such C09K3/14; polishing of semi-conductors H01L
• CPC Class Codes: C23F 3/00 Brightening metals by chemical means
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]
• CPC Class Codes: H01L 21/7684 Smoothing; Planarisation
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric

Abstract

A tantalum-based liner for copper metallurgy is selectively removed by chemical-mechanical planarization (CMP) in an acidic slurry of an oxidizer such as hydrogen peroxide, deionized water, a corrosion inhibitor such as BTA, and a surfactant such as Duponol SP, resulting in a high removal rate of the liner without appreciable removal of the exposed copper and with minimal dishing.

Claims

1. A method of co-planarizing copper or copper-based metallurgy and a refractory metal-based barrier layer or liner in an interlevel dielectric layer of a semiconductor device comprising the steps of:

planarizing said copper or copper-based metallurgy using a first slurry comprising an oxidizing agent comprising ferric nitrate, an oxidation inhibitor, a surfactant and an abrasive comprising alumina in water;

said first slurry having a pH of between 1.2 and 2.5 and said first slurry for removing copper selectively with respect to said barrier layer or liner, and

co-planarizing said barrier layer or liner and said interlevel dielectric layer using a second slurry consisting of a peroxide agent, a copper oxidation inhibitor, a surfactant, and an abrasive comprising silica in water;

said second slurry having a pH of between 3.0 and 7.5 and said second slurry for removing said barrier layer or liner.

2. The method of claim 1, wherein said second slurry removes said barrier layer or liner at a first removal rate and copper at a second removal rate, the first removal rate greater than the second removal rate.

3. The method of claim 2, wherein the first removal rate is about eight times greater than the second removal rate.

4. The method of claim 1, wherein said peroxide agent comprises hydrogen peroxide.

5. The method of claim 1, wherein said copper oxidation inhibitor comprises BTA.

6. The method of claim 1, wherein said surfactant regulates complexing between copper and the copper oxidation inhibitor.

7. The method of claim 6, wherein said surfactant comprises sodium lauryl sulfate.

8. The method of claim 1, wherein said abrasive comprises colloidal silica.