Method and apparatus for chemical-mechanical polishing

• US 6,340,434 B1
• Filed: 09/03/1998
• Issued: 01/22/2002
• Est. Priority Date: 09/05/1997
• Status: Expired due to Term

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Mizuno, Hiroshi, Ueno, Akihisa, Kinoshita, Osamu, Murohashi, Tetsuaki, Amberiadis, Kostas, Sakuma, Yoshifumi
• Primary Examiner(s): LUND, JEFFRIE ROBERT
• Application Number:
  US09/148,028
• Time in Patent Office: 1,237 Days
• Field of Search: 156/345, 216/88-90, 216/38, 216/52, 216/91, 438/690-692, 438/693, 451/285-287
• US Class Current: 216/38
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B24B 37/042 operating processes therefor
• CPC Class Codes: B24B 49/006 taking regard of the speed
• CPC Class Codes: B24B 49/16 taking regard of the load
• CPC Class Codes: H01L 21/3212 by chemical mechanical polishing [CMP]

Abstract

A method for chemical-mechanical polishing of a layer that is deposited on a surface of an integrated circuit substrate is described. The method includes: (1) immobilizing the integrated circuit substrate using a substrate holder such that the integrated circuit substrate surface is positioned against a surface of a polishing pad, which is mounted on a supporting surface; (2) a first stage of polishing the substrate surface including maintaining a predetermined difference between the rotational velocity of the polishing pad and the rotational velocity of the substrate holder allowing an endpoint of the chemical-mechanical polishing process of the layer to be detected; and (3) a second stage of polishing the substrate such that the rotational velocity of the polishing pad and the rotational velocity of the substrate holder are substantially the same to produce a substantially planar substrate surface.

Claims

1. A method for chemical-mechanical polishing of a layer that is deposited on a surface of an integrated circuit substrate, comprising:

immobilizing said integrated circuit substrate using a substrate holder, said integrated circuit substrate surface being positioned against a surface of a polishing pad and said polishing pad being mounted on a supporting surface;

a first stage of polishing said substrate surface including maintaining a difference between a rotational velocity of said polishing pad and a rotational velocity of said substrate holder allowing an endpoint of said chemical-mechanical polishing process of said layer to be detected; and

a second stage of polishing the substrate such that said rotational velocity of said polishing pad and said rotational velocity of said substrate holder are substantially the same to produce a substantially planar substrate surface.

2. The method of claim 1, further comprising introducing slurry on the polishing pad.

3. The method of claim 1, wherein said layer is a conductive layer that is disposed above a dielectric layer.

4. The method of claim 3, wherein said conductive layer includes tungsten.

5. The method of claim 1, wherein said integrated circuit substrate is a semiconductor wafer.

6. The method of claim 5, wherein said substrate holder is a wafer carrier.

7. The method of claim 1, wherein said supporting surface is a polishing table or a platen.

8. The method of claim 1, wherein the rotational velocity of the polishing pad is controlled by adjusting a rotational velocity of said supporting surface.

9. The method of claim 1, wherein the rotational velocity of the integrated circuit substrate surface is controlled by adjusting a rotational velocity of said substrate holder.

10. The method of claim 1, wherein said second stage of polishing includes rotating both said polishing pad and said integrated circuit substrate surface in the same direction.

11. The method of claim 1, wherein said second stage of polishing is carried out until said integrated circuit substrate surface is substantially planar and said substantially planar integrated circuit substrate surface facilitates alignment of an alignment tool above said integrated circuit substrate.

12. The method of claim 1, wherein in said first stage of polishing, said endpoint of said chemical-mechanical polishing process of said layer is detected by monitoring changes in current flow in a motor that is rotating the substrate holder.

13. The method of claim 1, wherein said first stage of polishing includes rotating both said polishing pad and said integrated circuit substrate surface in the same direction.

14. A method for chemical-mechanical polishing a layer deposited on a surface of a semiconductor wafer, comprising:

immobilizing the semiconductor wafer using a substrate holder pushing against a polishing pad that is mounted on a supporting surface;

supplying a polishing agent at the interface between the polishing pad and the semiconductor wafer;

a first stage of polishing said substrate surface including maintaining a difference between the rotational velocity of said polishing pad and the rotational velocity of said substrate holder allowing an endpoint of said chemical-mechanical polishing process of said layer to be detected; and

a second stage of polishing the substrate such that said rotational velocity of said polishing pad and said rotational velocity of said substrate holder are substantially the same to produce a substantially planar substrate surface.

15. The method of claim 14, wherein said polishing agent is a slurry having chemical characteristics.

16. The method of claim 14, wherein said second stage of polishing produces a substantially planar semiconductor wafer surface.

17. The method of claim 14, wherein said second stage of polishing includes rotating said polishing pad and said semiconductor wafer in a same direction.