Debonding a glass substrate from carrier using ultrasonic wave

• US 9,847,243 B2
• Filed: 08/27/2009
• Issued: 12/19/2017
• Est. Priority Date: 08/27/2009
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Carre, Alain Robert Emile, Garner, Sean Matthew, Waku-Nsimba, Jean
• Primary Examiner(s): Tucker, Philip
• Assistant Examiner(s): WU, VICKI H
• Application Number:
  US12/548,685
• Publication Number:
  US 20110048611A1
• Time in Patent Office: 3,036 Days
• Field of Search: 156 731
• CPC Class Codes: B32B 43/006 Delaminating
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/6836 Wafer tapes, e.g. grinding or dicing support tapes adhesive tapes in general C09J7/20
• CPC Class Codes: H01L 2221/68327 used during dicing or grinding
• CPC Class Codes: H01L 2221/6835 used as a support during build up manufacturing of active devices
• CPC Class Codes: H01L 2221/68381 Details of chemical or physical process used for separating the auxiliary support from a device or wafer
• CPC Class Codes: H01L 2221/68395 using peeling wheel
• CPC Class Codes: H01L 2924/19041 being a capacitor

Abstract

A process for making a device comprising a thin functional substrate comprising bonding the functional substrate to a carrier substrate, forming functional components on the functional subsrate, and debonding the functional substrate from the carrier substrate by applying ultrasonic wave to the bonding interface. The application of ultrasonic wave aids the debonding step by reducing the tensile stress the functional substrate may experience.

Claims

1. A process for making a device comprising a thin functional glass substrate having a first surface, a second surface opposite the first surface, and a thickness T1 between the first surface and the second surface, wherein T1≦

500 μ

m, comprising the following steps;

(A) bonding the first surface of the functional glass substrate to a carrier substrate having a thickness T2 that is greater than T1 by using a layer of elastomer bonding agent at a bonding interface including an outer periphery circumscribing a bonding area positioned between the first surface of the functional substrate and a bonding surface of the carrier substrate;

then

(B) processing the second surface of the functional substrate; and

then

(C) targeting an ultrasonic wave at a peripheral area of the outer periphery of the bonding interface to initiate debonding at the peripheral area of the bonding interface to achieve a preferential debonding of the layer of elastomer bonding agent from one of the functional glass substrate and the carrier substrate to release the carrier substrate from the functional substrate.

2. A process according to claim 1, wherein the bonding agent used in step (A) comprises at least one of a silicone adhesive and a perfluoro elastomer.

3. A process according to claim 1, wherein the layer of bonding agent is an elastomer having (a) a Shore A hardness in the range of 10 to 90;

and (b) a roughness of at most 183 nanometers.

4. A process according to claim 3, wherein the bond between the carrier substrate and the layer of bonding agent has a peel strength of at least 0.5 kilonewtons/meter when measured at a peeling speed of 20 millimeters/minute and a peeling angle of 90°

.

5. A process according to claim 1, wherein in step (C), the ultrasonic wave is targeted at the peripheral area of the outer periphery of the bonding interface through a liquid bath.

6. A process according to claim 5, wherein in step (C), the ultrasonic wave is targeted at the peripheral area of the outer periphery of the bonding interface through a liquid bath comprising an organic solvent having a surface tension lower than water at 20°

C.

7. A process according to claim 1, wherein step (C) further comprises, after targeting the ultrasonic wave at the peripheral area of the outer periphery of the bonding interface, peeling the functional substrate away from the carrier substrate.

8. A process according to claim 7, wherein during the step of peeling the functional substrate away from the carrier substrate, the peeling radius is at least 5 cm.

9. A process according to claim 1, wherein the functional substrate has a thickness T1 of at most 400 μ

m.

10. A process according to claim 1, wherein in step (A), the layer of bonding agent at the bonding interface has a thickness of at most 300 μ

m.

11. A process according to claim 1, wherein step (B) forms a functional component and in step (C), the ultrasonic wave is targeted such that the functional component formed in step (B) is not damaged.

12. A process according to claim 1, wherein the layer of the bonding agent has a stronger adhesion to the carrier substrate than to the functional substrate.

13. A process according to claim 12, wherein at the end of step (C), the carrier substrate remains bonded to the layer of the bonding agent.

14. A process according to claim 1, wherein step (A) comprises:

(A01) applying a pre-polymerization layer of the bonding agent on a surface of the carrier substrate; and

subsequently

(A02) polymerizing the pre-polymerization layer to obtain a polymerized layer of the bonding agent bonded to the carrier substrate; and

(A03) placing the first surface of the functional substrate over the polymerized layer of bonding agent to achieve a bond with the functional substrate that is weaker than the bond between the bonding agent and the carrier substrate.

15. A process according to claim 1, wherein step (A) comprises:

(A11) forming a first layer of a first coating over a surface of the carrier substrate;

(A12) applying the layer of the bonding agent between the first layer of the first coating and the first surface of the functional state.

16. A process according to claim 15, wherein in step (A11), the first layer of the first coating comprises a silane.

17. A process according to claim 1, wherein after step (C), the carrier substrate bonding to the layer bonding agent is reused in a cycle of processing another functional substrate.

18. A process according to claim 1, wherein the functional substrate comprises multiple layers of glass and polymer such as polyimide.

19. A process according to claim 1, wherein step (C) achieves preferential debonding of the layer of elastomer bonding agent from the functional glass substrate while the layer of elastomer bonding agent remains bonded to the carrier substrate.

20. A process according to claim 1, wherein, after targeting the ultrasonic wave at the peripheral area of the outer periphery of the bonding interface to initiate debonding at the peripheral area of the bonding interface, step (C) further includes directing the ultrasonic wave to scan a full area of the bonding interface to achieve sequential debonding of the carrier substrate from the functional substrate.

24. A process according to claim 1, wherein step (C) releases the entire carrier substrate from the functional glass substrate.

21. A process for making a device comprising a thin functional glass substrate having a first surface, a second surface opposite the first surface, and a thickness T1 between the first surface and the second surface, wherein T1≦

500 μ

m, comprising the following steps;

(A) bonding the first surface of the functional glass substrate to a carrier substrate having a thickness T2 that is greater than T1 by using a layer of elastomer bonding agent at a bonding interface including an outer periphery circumscribing a bonding area positioned between the first surface of the functional substrate and a bonding surface of the carrier substrate;

then

(B) processing the second surface of the functional substrate; and

then

(C) targeting an ultrasonic wave at a peripheral area of the outer periphery of the bonding interface to initiate debonding at the peripheral area of the bonding interface to begin releasing the carrier substrate from the functional substrate.

22. A process according to claim 21, wherein step (C) includes using a waveguide to provide a predetermined travel path for the ultrasonic wave to selectively guide the ultrasonic wave to the peripheral area of the bonding interface.

23. A process according to claim 22, wherein the waveguide comprises a quantity of liquid configured to channel the ultrasonic wave to travel along the predetermined travel path.

25. A process according to claim 21, wherein after step (C), further comprising step (D) of releasing the entire carrier substrate from the functional glass substrate.