Systems and Methods for Cleaving A Bonded Wafer Pair

• US 20130062020A1
• Filed: 03/12/2012
• Published: 03/14/2013
• Est. Priority Date: 03/15/2011
• Status: Active Grant

• Current Assignee: GlobalWafers Co., Ltd. (Sino-American Silicon Products Incorporated)
• Original Assignee: SunEdison, Inc.
• Inventors: Ries, Michael John, Libbert, Jeffrey L., Witte, Dale A.
• Granted Patent: US 8,845,859 B2
• Time in Patent Office: Days
• US Class Current: 156/715
• CPC Class Codes: B23B 49/006 Attached to drilling machines
• CPC Class Codes: B32B 43/006 Delaminating
• CPC Class Codes: C09J 2301/502 process for debonding adherents
• CPC Class Codes: H01L 21/67092 Apparatus for mechanical treatment or grinding or cutting, see the relevant groups in subclasses B24B or B28D
• CPC Class Codes: H01L 21/76254 with separation/delamination along an ion implanted layer, e.g. Smart-cut, Unibond
• CPC Class Codes: Y10S 156/93 Semiconductive product delaminating, e.g. delaminating emiconductive wafer from underlayer
• CPC Class Codes: Y10S 156/941 Means for delaminating semiconductive product
• CPC Class Codes: Y10T 156/1168 Gripping and pulling work apart during delaminating
• CPC Class Codes: Y10T 156/1174 Using roller for delamination [e.g., roller pairs operating at differing speeds or directions, etc.]
• CPC Class Codes: Y10T 156/1184 Piercing layer during delaminating [e.g., cutting, etc.]
• CPC Class Codes: Y10T 156/19 Delaminating means
• CPC Class Codes: Y10T 156/195 Delaminating roller means
• CPC Class Codes: Y10T 156/1956 Roller pair delaminating means
• CPC Class Codes: Y10T 156/1978 Delaminating bending means

Abstract

Systems and methods are provided for mechanically cleaving a bonded wafer pair by controlling the rate of cleaving. This controlled rate of cleaving results in a reduction or elimination of non-uniform thickness variations in the cleaved surface of the resulting SOI wafer. One embodiment uses flexible chucks attached to the faces of the wafers and actuators attached to the flexible chucks to cleave the bonded wafer pair. Other embodiments also use rollers in contact with the surfaces to control the rate of cleaving.

Claims

1. A system for cleaving a bonded wafer pair having a first face and a second face, the system comprising:

a flexible chuck for attachment to the first face of the wafer pair; and

an actuator attached to the flexible chuck for application of force on the flexible chuck, the application of force on the flexible chuck causing the cleaving of the bonded wafer pair.

2. The system of claim 1 wherein the actuator is attached to the flexible chuck with adhesive.

3. The system of claim 1 wherein the actuator is selectively attachable to the flexible chuck using vacuum.

4. The system of claim 1 wherein the flexible chuck comprises a flexible wafer support and a flexible plate, the flexible wafer support having a first surface for attachment to the first face of the wafer pair and an opposing second surface for attachment to a first surface of the flexible plate.

5. The system of claim 1 wherein the flexible chuck has a stiffness less than or equal to a stiffness of the bonded wafer pair.

6. The system of claim 1 wherein the flexible chuck is a first flexible chuck and the system further comprises a second flexible chuck connected to the second face of the wafer pair.

7. The system of claim 6 wherein the actuator is a first actuator and the system further comprises a second actuator connected to the second flexible chuck for application of force to the second face.

8. A system for cleaving a bonded wafer pair having a first face and a second face, the system comprising:

a flexible chuck for attachment to the first face of the wafer pair;

an actuator for attachment to the flexible chuck;

a movable roller positionable adjacent the actuator for application of force on the flexible chuck and movable along the flexible chuck,

wherein the position of the roller controls the propagation of the cleave of the bonded wafer pair.

9. The system of claim 8 wherein the actuator is attached to the flexible chuck with adhesive.

10. The system of claim 8 wherein the actuator is selectively attachable to the flexible chuck using vacuum.

11. The system of claim 8 further comprising a blade for insertion between layers of the bonded wafer pair to initiate cleaving of the bonded wafer pair.

12. The system of claim 8 wherein the flexible chuck is a first flexible chuck and the system further comprises a second flexible chuck connected to the second face of the wafer pair.

13. The system of claim 12 wherein the actuator is a first actuator and the system further comprises a second actuator connected to the second flexible chuck for application of force to the second face.

14. The system of claim 13 wherein the movable roller is a first movable roller and the system further comprises a second movable roller positioned adjacent the second actuator for application of force on the second flexible chuck and movable along the second flexible chuck.

15. A system for cleaving a bonded wafer pair having a first face and a second face, the system comprising:

a first flexible chuck for attachment to the first face of the wafer pair;

a second flexible chuck for attachment to the second face of the wafer pair;

a first vacuum attachment for attachment to the first flexible chuck;

a second vacuum attachment for attachment to the second flexible chuck;

a movable first roller positionable adjacent the first vacuum attachment for application of force on the first flexible chuck and movable along the first flexible chuck; and

a movable second roller positionable adjacent the second vacuum attachment for application of force on the second flexible chuck and movable along the second flexible chuck,

wherein the position of the first and second rollers controls the propagation of the cleave of the wafer pair.

16. The system of claim 15 further comprising a blade for insertion between layers of the bonded wafer pair to initiate cleaving of the bonded wafer pair.

17. The system of claim 15 wherein an upward force is applied to the first face of the bonded wafer pair by the first vacuum attachment.

18. The system of claim 17 wherein a downward force is applied to the second face of the bonded wafer pair by the second vacuum attachment.

19. A method of cleaving a bonded wafer pair having a first face and a second face, the method comprising:

attaching a flexible chuck to the first face of the wafer pair;

attaching an actuator to the flexible chuck;

applying force on the flexible chuck and the first face of the wafer with the actuator to separate layers of the bonded wafer pair and cleave the bonded wafer pair.

20. The method of claim 19 wherein the actuator is attached to the flexible chuck with vacuum.

21. The method of claim 19 further comprising inserting a blade between layers of the bonded wafer pair to initiate cleaving of the bonded wafer pair.

22. The method of claim 19 further comprising positioning a movable roller adjacent the actuator and applying force on the flexible chuck with the movable roller.

23. The method of claim 22 further comprising controlling the propagation of the cleave of the wafer pair by moving the roller.