Polishing pad with window and method of fabricating a window in a polishing pad

• US 7,118,450 B2
• Filed: 09/12/2005
• Issued: 10/10/2006
• Est. Priority Date: 03/28/1995
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Birang, Manoocher, Gleason, Allan, Guthrie, William L.
• Primary Examiner(s): Wilson, Lee D.
• Application Number:
  US11/225,838
• Publication Number:
  US 20060014476A1
• Time in Patent Office: 393 Days
• Field of Search: 451/6, 451 7- 10, 451285-289, 451/41, 451/28, 451/526, 451/539
• US Class Current: 451/6
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: B24B 37/205 provided with a window for inspecting the surface of the work being lapped
• CPC Class Codes: B24B 47/12 by mechanical gearing or electric power B24B47/16 takes precedence
• CPC Class Codes: B24B 49/04 involving measurement of the workpiece at the place of grinding during grinding operation
• CPC Class Codes: B24B 49/12 involving optical means
• CPC Class Codes: B24B 51/00 Arrangements for automatic control of a series of individual steps in grinding a workpiece if applicable to other machine tools, G05B takes precedence
• CPC Class Codes: B24D 18/00 Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for
• CPC Class Codes: G01B 11/06 for measuring thickness ; e.g. of sheet material thickness measurement by thermal means G01B21/085
• CPC Class Codes: G01B 11/0683 measurement during deposition or removal of the layer

Abstract

The polishing pad for a chemical mechanical polishing apparatus, and a method of making the same. The polishing pad has a covering layer with a polishing surface and a backing layer which is adjacent to the platen. A first opening in the covering layer with a first cross-sectional area and a second opening in the backing layer with a second, different cross-sectional area form an aperture through the polishing pad. A substantially transparent polyurethane plug is positioned in the aperture, and an adhesive material fixes the plug in the aperture.

Claims

1. A polishing pad assembly for a chemical mechanical polishing apparatus, comprising:

a polishing pad having a polishing surface;

an aperture formed through the polishing pad; and

a solid, substantially transparent window spanning the aperture and attached to the polishing pad, wherein a portion of the polishing pad extends laterally over the window.

2. The polishing pad assembly of claim 1, wherein the window is secured to the polishing pad by an adhesive.

3. The polishing pad assembly of claim 1, wherein the polishing pad includes a polishing layer with the polishing surface, and the window is secured to the polishing layer.

4. The polishing pad assembly of claim 3, wherein the window is secured to the polishing layer by an adhesive.

5. The polishing pad assembly of claim 4, wherein the window is secured to a bottom surface of the polishing layer by the adhesive.

6. The polishing pad assembly of claim 3, wherein the polishing pad includes a backing layer below the polishing layer.

7. The polishing pad assembly of claim 6, wherein the portion of the polishing layer projects laterally past the backing layer, and the window is secured to a bottom surface of the portion of the polishing layer.

8. The polishing pad assembly of claim 1, wherein the window is located in the aperture.

9. The polishing pad assembly of claim 8, wherein the aperture includes a first portion proximal to the polishing surface with a first lateral dimension and a second portion distal to the polishing surface with a second, different lateral dimension.

10. The polishing pad assembly of claim 9, wherein the first lateral dimension is smaller than the second lateral dimension.

11. A method of assembling a polishing pad assembly, compnsing:

providing a polishing pad having a polishing surface and an aperture formed through the polishing pad; and

bringing a solid, substantially transparent window into contact with the polishing pad such that the window spans the aperture and a portion of the polishing pad extends laterally over the window.

12. The method of claim 11, further comprising adhesively securing the window to the polishing pad.

13. The method of claim 11, wherein the polishing pad includes a polishing layer with the polishing surface, and the window is secured to the polishing layer.

14. The method of claim 13, wherein the polishing pad includes a backing layer below the polishing layer.

15. The method of claim 14, wherein the portion of the polishing layer projects laterally past the backing layer, and the window is secured to a bottom surface of the portion of the polishing layer.

16. The method of claim 13, further comprising adhesively securing the window to the polishing layer.

17. The method of claim 16, further comprising adhesively securing the window to a bottom surface of the polishing layer.