Tape residue-free bump area after wafer back grinding

• US 8,642,390 B2
• Filed: 03/17/2010
• Issued: 02/04/2014
• Est. Priority Date: 03/17/2010
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Wang, Chung Yu, Wang, Jiann-Jong
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US12/726,317
• Publication Number:
  US 20110230043A1
• Time in Patent Office: 1,420 Days
• Field of Search: 438/613, 438/612, 438/108, 438/114, 438/118, 438/459, 257/E21.499
• US Class Current: 438/114
• 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 2221/68381 Details of chemical or physical process used for separating the auxiliary support from a device or wafer
• CPC Class Codes: H01L 2221/68386 Separation by peeling
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/0568 Molybdenum [Mo] as principal constituent
• CPC Class Codes: H01L 2224/1132 Screen printing, i.e. using a stencil
• CPC Class Codes: H01L 2224/1146 Plating
• CPC Class Codes: H01L 2224/11849 Reflowing
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/14 Integrated circuits

Abstract

Organic-adhesive tapes are often used to secure and protect the bumps during wafer processing after bump formation. While residual organic-adhesive tape may remain on the wafer after tape de-lamination, applying a bump template layer on the bumps before laminating the tape allows any residue to be removed afterwards and results in a residue-free wafer.

Claims

1. A method comprising:

providing a partially fabricated semiconductor device on a substrate having a first surface and bumps thereon;

applying a bump template layer on the bumps;

laminating an organic-adhesive tape directly over the first surface, wherein the organic-adhesive tape is over the bumps;

de-laminating the organic-adhesive tape from the first surface, wherein a portion of the organic-adhesive tape remains adhered on the bumps; and

,

removing all of the portion of the organic-adhesive tape and the bump template layer by cleaning the first surface with a first solution.

2. The method of claim 1, wherein the bumps are solder alloy, gold, or copper.

3. The method of claim 1, further comprising backgrinding a second surface of the substrate before de-laminating the organic-adhesive tape.

4. The method of claim 1, further comprising exposing the organic-adhesive tape to UV radiation before de-laminating the organic-adhesive tape.

5. The method of claim 1, wherein applying a bump template layer comprises:

dipping the substrate in a thin viscous layer of organic template material; and

heating the first surface to form the bump template layer.

6. The method of claim 5, wherein the organic template material does not contact the first surface during the dipping operation.

7. The method of claim 4, wherein the heating operation comprises increasing the substrate temperature to between 75 degrees Celsius and 150 degrees Celsius for between 1 minute and 3 minutes.

8. The method of claim 1, wherein applying a bump template layer comprises:

coating the first surface and bumps with a bump template material;

curing the bump template material on the bumps without curing the bump template material on the first surface; and

removing uncured bump template material from the first surface.

9. The method of claim 1, wherein applying a bump template layer comprises:

coating the first surface and bumps with a bump template material, wherein the bump template material forms a wetting layer on the bumps but not on the first surface;

removing the bump template material from the first surface; and

,

forming a bump template layer from the wetting layer.

10. The method of claim 9, wherein removing the bump template material from the first surface comprises cleaning the first surface with a second solution, wherein the second solution is different from the first solution.

11. The method of claim 1, wherein the bump template layer comprises a resin.

12. The method of claim 1, wherein the organic-adhesive tape is a backgrinding tape.

13. The method of claim 1, wherein the bump template layer comprises a water soluble organic material.

14. The method of claim 1, wherein the bump template layer comprises a polyethylene glycol ether.

15. The method of claim 1, wherein said bump template layer does not cover bumpless areas of the first surface.

16. The method of claim 1, wherein the first surface comprises a polyimide layer.

17. A method of manufacturing residue-free post-thinning wafer, said method comprising:

providing a partially fabricated semiconductor substrate having a first surface and bumps thereon;

dipping the substrate in an organic template to form a bump template layer;

laminating an adhesive tape directly over the first surface, wherein the organic-adhesive tape is over the bumps;

thinning the substrate from a second surface opposite of the first surface;

de-laminating the adhesive tape from the first surface, wherein a portion of the adhesive tape remains adhered on the bumps; and

,

removing all of the portion of the adhesive tape and the bump template layer by cleaning the first surface with a solution.

18. The method of claim 17, wherein the de-laminating operation comprises:

exposing the adhesive tape to UV radiation; and

pulling the adhesive tape away from the first surface.

19. The method of claim 17, wherein the organic template coats the bumps and substantially not the first surface where there is no bump.

20. The method of claim 17, wherein the solution is at least one of de-ionized water, alcohol, acetone, or an ether.