Method of backgrinding wafers while leaving backgrinding tape on a chuck

• US 20030134578A1
• Filed: 12/10/2002
• Published: 07/17/2003
• Est. Priority Date: 09/27/2000
• Status: Active Grant

• Current Assignee: Revasum, Inc.
• Original Assignee: Strasbaugh Co.
• Inventors: Kassir, Salman M., Strasbaugh, Alan
• Granted Patent: US 6,866,564 B2
• Time in Patent Office: Days
• US Class Current: 451/41
• CPC Class Codes: B24B 37/30 for single side lapping of plane surfaces
• CPC Class Codes: H01L 21/67132 Apparatus for placing on an insulating substrate, e.g. tape
• CPC Class Codes: Y10T 156/1092 All laminae planar and face to face
• CPC Class Codes: Y10T 156/17 Surface bonding means and/or assemblymeans with work feeding or handling means
• CPC Class Codes: Y10T 156/1744 Means bringing discrete articles into assembled relationship

Abstract

A method of backgrinding wafers wherein backgrinding tape or a pad is applied to the chuck and not to the wafers. The backgrinding tape or pad is left on the chuck as each wafer is sequentially placed on the tape or pad, background, and then removed from the tape. A tool for applying tape to a chuck, as described herein, facilitates this method.

Claims

1. A method of preparing a wafer, said method comprising the steps of:

a) providing a wafer having a front side and a back side;

b) processing the wafer such that the wafer has a flatness and a thickness suitable for building-up a device on the front side of the wafer;

c) building-up a device onto the front side of the wafer;

d) providing a chuck and a tape, wherein the chuck is suitable for supporting the tape during a backgrinding process, and wherein the tape is suitable for supporting the wafer;

e) after building up the device, placing the tape onto the chuck;

f) placing the front side of the wafer onto the tape;

g) securing the front side of the wafer to the tape;

h) grinding the back side of the wafer; and

i) removing the wafer from the tape.

2. The method of claim 1 comprising the further steps of:

providing a second wafer having a front side and a back side;

processing the second wafer such that the second wafer has a flatness and a thickness suitable for building-up a device on the front side of the second wafer;

building-up a device onto the front side of the second wafer; and

repeating steps e) through i) on the second wafer while leaving the tape on the chuck.

3. The method of claim 1 wherein the step of removing the wafer from the tape comprises the step of removing the wafer from the tape without removing the tape from the chuck.

4. The method of claim 1 comprising the further steps of:

providing a second wafer having a front side and a backside, wherein a device is built up on the front side of the second wafer;

after removing the wafer from the tape, leaving the tape on the chuck and then securing the front side of the second wafer to the tape;

grinding the back side of the second wafer; and

removing the second wafer from the tape.

5. The method of claim 4 wherein the step of removing the second wafer from the tape comprises the step of removing the second wafer from the tape without removing the tape from the chuck.

6. The method of claim 1 comprising the further steps of:

providing a plurality of wafers, wherein each of the plurality of wafers has a front side and a back side and wherein each of the plurality of wafers has a device built-up on the front side;

sequentially placing on the tape and then removing from the tape the front side of each of the plurality of wafers while leaving the tape on the chuck; and

grinding the back side of each of the plurality of wafers before removing each of the plurality of wafers from the tape.

7. The method of claim 6 wherein the step of providing a chuck and a tape comprises providing a resilient tape.

8. The method of claim 1 wherein:

the step of providing a chuck and a tape further comprises providing a chuck capable of communicating a vacuum and providing a tape capable of communicating a vacuum;

the step of securing the front side of the wafer to the tape comprises securing the front side of the wafer to the tape by applying a vacuum through the chuck and the tape; and

the step of removing the wafer from the tape further comprises releasing vacuum and then removing the wafer from the tape.

9. The method of claim 8 wherein the step of providing a chuck and a tape further comprises providing a chuck having a face that includes a pattern of holes and providing a tape having a matching pattern of apertures, said method comprising the further steps of:

positioning the tape so that the apertures in the tape are in registration with the holes in the face of the chuck.

10. The method of claim 1 wherein the step of providing a chuck and a tape further comprises providing a resilient tape.

11. A method of preparing a wafer, said method comprising the steps of:

providing a wafer having a front side and a back side;

processing the wafer such that the wafer has a flatness and a thickness suitable for building-up a device on the front side of the wafer;

building-up a device onto the front side of the wafer;

providing a chuck, wherein the chuck is suitable for supporting a tape during a backgrinding process and wherein the chuck is capable of communicating a vacuum;

providing a tape having a wafer side suitable for supporting the wafer and a chuck side suitable for resting on a chuck, wherein the chuck side of the tape is adhesive and the wafer side of the tape is non-adhesive; and

wherein the tape is capable of communicating a vacuum;

placing the chuck side of the tape onto the chuck;

after building up the device, placing the front side of the wafer onto the wafer side of the tape;

securing the front side of the wafer to the wafer side of the tape by applying a vacuum through the chuck and the tape;

grinding the back side of the wafer;

releasing the vacuum; and

removing the wafer from the tape.

12. The method of claim 11 comprising the further steps of:

providing a second wafer having a front side and a backside, wherein a device is built up on the front side of the second wafer;

after removing the wafer from the tape, leaving the tape on the chuck and then securing the front side of the second wafer to the tape by reapplying the vacuum through the chuck and tape;

grinding the back side of the second wafer;

releasing the vacuum; and

removing the second wafer from the tape.

13. The method of claim 12 wherein the step of removing the second wafer from the tape comprises the step of removing the second wafer from the tape without removing the tape from the chuck.

14. The method of claim 13 wherein the step of providing a tape further comprises providing a resilient tape.

15. The method of claim 11 comprising the further steps of:

providing a plurality of wafers, wherein each of the plurality of wafers has a front side and a back side and wherein each of the plurality of wafers has a device built-up on the front side;

sequentially placing on the tape and then removing from the tape the front side of each of the plurality of wafers while leaving the tape on the chuck; and

grinding the back side of each of the plurality of wafers before removing each of the plurality of wafers from the tape.

16. The method of claim 11 wherein the step of removing the wafer from the tape comprises the step of removing the wafer from the tape without removing the tape from the chuck.

17. The method of claim 11 wherein the step of providing a tape further comprises providing a resilient tape.

18. The method of claim 11 comprising the further step of adhering the front side of the wafer to the tape with a weak adhesive.

19. The method of claim 11 wherein the step of providing a chuck and a tape further comprises providing a chuck having a face that includes a pattern of holes and providing a tape having a matching pattern of apertures, said method comprising the further steps of:

positioning the tape so that the apertures in the tape are in registration with the holes in the face of the chuck.

20. The method of claim 11 wherein the step of providing a tape further comprises providing a resilient tape and wherein the method comprises the further step of adhering the front side of the wafer to the tape with a weak adhesive.

21. A method of preparing a wafer, said method comprising the steps of:

a) providing a wafer having a front side and a back side;

b) processing the wafer such that the wafer has a flatness and a thickness suitable for building-up a device on the front side of the wafer;

c) building-up a device onto the front side of the wafer;

d) providing a chuck and a pad, wherein the chuck is suitable for supporting the pad during a backgrinding process, and wherein the pad is suitable for supporting the wafer;

e) after building up the device, placing the pad onto the chuck;

f) placing the front side of the wafer onto the pad;

g) securing the front side of the wafer to the pad;

h) grinding the back side of the wafer; and

i) removing the wafer from the pad.

22. The method of claim 21 comprising the further steps of:

providing a second wafer having a front side and a back side;

processing the second wafer such that the second wafer has a flatness and a thickness suitable for building-up a device on the front side of the second wafer;

building-up a device onto the front side of the second wafer; and

repeating steps e) through i) on the second wafer while leaving the pad on the chuck.

23. The method of claim 21 wherein the step of removing the wafer from the pad comprises the step of removing the wafer from the pad without removing the pad from the chuck.

24. The method of claim 21 comprising the further steps of:

providing a second wafer having a front side and a backside, wherein a device is built up on the front side of the second wafer;

after removing the wafer from the pad, leaving the pad on the chuck and then securing the front side of the second wafer to the pad;

grinding the back side of the second wafer; and

removing the second wafer from the pad.

26. The method of claim 21 comprising the further steps of:

providing a plurality of wafers, wherein each of the plurality of wafers has a front side and a back side and wherein each of the plurality of wafers has a device built-up on the front side;

sequentially placing on the pad and then removing from the pad the front side of each of the plurality of wafers while leaving the pad on the chuck; and

grinding the back side of each of the plurality of wafers before removing each of the plurality of wafers from the pad.

27. The method of claim 26 wherein the step of providing a chuck and a pad comprises providing a resilient pad.

28. The method of claim 21 wherein:

the step of providing a chuck and a pad further comprises providing a chuck capable of communicating a vacuum and providing a pad capable of communicating a vacuum;

the step of securing the front side of the wafer to the pad comprises securing the front side of the wafer to the pad by applying a vacuum through the chuck and the pad; and

the step of removing the wafer from the pad further comprises releasing vacuum and then removing the wafer from the pad.

29. The method of claim 28 wherein the step of providing a chuck and a pad further comprises providing a chuck having a face that includes a pattern of holes and providing a pad having a matching pattern of apertures, said method comprising the further steps of:

positioning the pad so that the apertures in the pad are in registration with the holes in the face of the chuck.

30. The method of claim 21 wherein the step of providing a chuck and a pad further comprises providing a resilient pad.

25. The method of claim 25 wherein the step of removing the second wafer from the pad comprises the step of removing the second wafer from the pad without removing the pad from the chuck.

31. A method of preparing a wafer, said method comprising the steps of:

providing a wafer having a front side and a back side;

processing the wafer such that the wafer has a flatness and a thickness suitable for building-up a device on the front side of the wafer;

building-up a device onto the front side of the wafer;

providing a chuck, wherein the chuck is suitable for supporting a pad during a backgrinding process and wherein the chuck is capable of communicating a vacuum;

providing a pad having a wafer side suitable for supporting the wafer and a chuck side suitable for resting on a chuck, wherein the chuck side of the pad is adhesive and the wafer side of the pad is non-adhesive; and

wherein the pad is capable of communicating a vacuum;

placing the chuck side of the pad onto the chuck;

after building up the device, placing the front side of the wafer onto the wafer side of the pad;

securing the front side of the wafer to the wafer side of the pad by applying a vacuum through the chuck and the pad;

grinding the back side of the wafer;

releasing the vacuum; and

removing the wafer from the pad.

32. The method of claim 31 wherein the step of providing a pad further comprises providing a resilient pad and wherein the method comprises the further step of adhering the front side of the wafer to the pad with a weak adhesive.

33. The method of claim 31 comprising the further steps of:

providing a second wafer having a front side and a backside, wherein a device is built up on the front side of the second wafer;

after removing the wafer from the pad, leaving the pad on the chuck and then securing the front side of the second wafer to the pad by reapplying the vacuum through the chuck and pad;

grinding the back side of the second wafer;

releasing the vacuum; and

removing the second wafer from the pad.

34. The method of claim 33 wherein the step of removing the second wafer from the pad comprises the step of removing the second wafer from the pad without removing the pad from the chuck.

35. The method of claim 34 wherein the step of providing a pad further comprises providing a resilient pad.

36. The method of claim 31 comprising the further steps of:

providing a plurality of wafers, wherein each of the plurality of wafers has a front side and a back side and wherein each of the plurality of wafers has a device built-up on the front side;

sequentially placing on the pad and then removing from the pad the front side of each of the plurality of wafers while leaving the pad on the chuck; and

grinding the back side of each of the plurality of wafers before removing each of the plurality of wafers from the pad.

37. The method of claim 31 wherein the step of removing the wafer from the pad comprises the step of removing the wafer from the pad without removing the pad from the chuck.

38. The method of claim 31 wherein the step of providing a pad further comprises providing a resilient pad.

39. The method of claim 31 comprising the further step of adhering the front side of the wafer to the pad with a weak adhesive.

40. The method of claim 31 wherein the step of providing a chuck and a pad further comprises providing a chuck having a face that includes a pattern of holes and providing a pad having a matching pattern of apertures, said method comprising the further steps of:

positioning the pad so that the apertures in the pad are in registration with the holes in the face of the chuck.