PROTECTION OF WORK PIECE DURING SURFACE PROCESSING

• US 20030211813A1
• Filed: 04/08/2003
• Published: 11/13/2003
• Est. Priority Date: 04/09/2002
• Status: Active Grant

• Current Assignee: Revasum, Inc.
• Original Assignee: Strasbaugh Co.
• Inventors: Kassir, Salman Moudrek, Spiegel, Larry A.
• Granted Patent: US 7,018,268 B2
• Time in Patent Office: Days
• US Class Current: 451/28
• CPC Class Codes: B23B 2226/18 Ceramic
• CPC Class Codes: B23B 31/307 Vacuum chucks
• CPC Class Codes: B24B 37/30 for single side lapping of plane surfaces
• CPC Class Codes: H01L 21/6838 with gripping and holding devices using a vacuum; Bernoulli devices

Abstract

The present invention provides an apparatus and method for protecting a work piece during surface processing. The apparatus employs a protective material to protect a wafer during backside grinding. The apparatus can further include a vacuum chuck that allows the passage of a vacuum signal, a frame holding the protective material, a frame holder to hold the frame, and a fastening arrangement to fasten the frame holder to the chuck adjacent a support surface. The method provided by the invention can include providing a vacuum chuck, placing a protective material in contact with the chuck, placing a wafer in contact with the protective material, applying a vacuum signal securing the wafer with the chuck, and grinding the backside surface of the wafer.

Claims

1. An arrangement for supporting a work piece having opposed first and second surfaces while operations are carried out on the first surface, to protect the second surface, comprising:

a vacuum chuck having a support surface, the vacuum chuck being at least partially porous to allow passage of a vacuum signal therethrough;

a frame;

a protective material held by the frame;

said frame and said protective material together comprising a frame assembly;

a frame holder to hold the frame assembly to the vacuum chuck; and

a fastening arrangement to fasten the frame holder to the vacuum chuck adjacent the support surface.

2. The arrangement of claim 1 wherein the frame holder releasably holds the frame assembly.

3. The arrangement of claim 2 further comprising magnetic material on said frame holder to hold said frame to said frame holder.

4. The arrangement of claim 1 wherein said frame includes a ring-shaped body.

5. The arrangement of claim 1 wherein said frame comprises a plurality of laminated rings.

6. The arrangement of claim 1 wherein said protective material is secured to said frame with an adhesive.

7. The arrangement of claim 1 wherein said protective material is held under tension by the frame.

8. The arrangement of claim 1 wherein said protective material comprises a polymeric film mesh.

9. The arrangement of claim 1 wherein said protective material comprises a woven fabric.

10. The arrangement of claim 1 wherein said protective material comprises a fabric with vacuum holes defined by warp and weft fibers.

11. The arrangement of claim 10 wherein said vacuum holes are arranged in a regularly spaced pattern.

12. The arrangement of claim 1 wherein said work piece comprises a semiconductor wafer of predetermined size.

13. The arrangement of claim 1 wherein said protective material comprises a film sheet that is perforated to form vacuum holes.

14. The arrangement of claim 13 wherein said film sheet is generally nonporous.

15. The arrangement of claim 1 wherein said fastening arrangement comprises a plurality of threaded fasteners securing said frame holder to said vacuum chuck and a plurality of springs between said frame holder and said fastening arrangement.

16. The arrangement of claim 15 further comprising a plurality of pins extending from said frame holder and received in a plurality of openings defined by the frame.

17. The arrangement of claim 1 wherein said protective material is porous so as to allow passage of the vacuum signal from said vacuum chuck to said work piece.

18. The arrangement of claim 17, wherein the protective material is a non-adhering material.

19. A method of back grinding a semiconductor wafer having an initial thickness, a front side surface with circuitry and an opposed backside surface, comprising the steps of:

providing a protective material having a first surface for contact with the front side surface of said wafer;

providing a vacuum chuck having a support surface, the vacuum chuck being at least partially porous to allow passage of the vacuum signal therethrough;

placing said protective material in contact with said support surface;

placing the front side surface of said wafer in contact with the first surface of said protective material;

applying the vacuum signal through said protective material with said vacuum chuck to thereby communicate the vacuum signal with the front side surface of said wafer securing the wafer with the vacuum chuck;

processing the backside surface of said wafer;

removing the vacuum signal to release said wafer; and

removing said wafer from said protective material.

20. The method of claim 19 further comprising the steps of:

providing a frame;

securing the protective material to the frame; and

securing the frame to the vacuum chuck.

21. The method of claim 20 wherein the step of securing the protective material to the frame comprises stretching the protective material on said frame.

22. The method of claim 20 wherein the step of securing the protective material to the frame comprises the steps of providing an adhesive and securing the protective material to the frame with said adhesive.

23. The method of claim 20 wherein the step of securing the frame to the vacuum chuck comprises the steps of:

providing a frame holder having magnetic material; and

securing the frame holder to said vacuum chuck, whereby said frame is releasably secured to said vacuum chuck.

24. The method of claim 23 wherein the step of securing the frame holder to said vacuum chuck comprises the step of resiliently securing the frame holder to said vacuum chuck.

25. The method of claim 19 wherein the step of providing said protective material comprises the steps of providing a fabric having warp and weft fibers, and defining a series of vacuum holes with the warp and weft fibers.

26. The method of claim 25 further comprising the step of arranging said vacuum holes in a regularly spaced, generally rectilinear grid.

27. The method of claim 19 wherein the step of providing said protective material comprises the steps of providing a protective film sheet and perforating said film sheet to form vacuum holes.

28. An apparatus for use in protecting a semiconductor wafer during processing, comprising:

a frame; and

a protection material secured across the frame, wherein the protection material has an area greater than an area of a first surface of the semiconductor wafer.

29. The apparatus of claim 28, wherein the protection material is secured across the frame such that the protection material is under tension.

30. The apparatus of claim 29, further comprising adhesive applied about the frame such that the adhesive secures the protective material with the frame.

31. A method for use in assembling a frame assembly capable of use in protecting a wafer during processing, comprising:

applying a tensile force to a protective material; and

positioning the protective material over a frame, wherein the frame has an area greater than an area of the wafer; and

securing the protective material with the frame.

32. The method of claim 31, further comprising:

applying an adhesive about a surface of the frame, wherein the securing the protective material with the frame includes securing the protective material with the adhesive.

33. The method of claim 32, wherein the applying the tensile force includes applying the tensile force at a predefined level to achieve pores within the protective material with an average pore size being of at least a predefined pore size limit.