Substrate dividing method

Patent metadata

Field	Value
Publication number	US-9548246-B2
Application number	US-201615226519-A
Country	US
Kind code	B2
Filing date	Aug 2, 2016
Priority date	Mar 12, 2002
Publication date	Jan 17, 2017
Grant date	Jan 17, 2017

Abstract

A substrate dividing method which can thin and divide a substrate while preventing chipping, and cracking from occurring. This substrate dividing method comprises the steps of irradiating a semiconductor substrate 1 having a front face 3 formed with functional devices 19 with laser light while positioning a light-converging point within the substrate, so as to form a modified region including a molten processed region due to multiphoton absorption within the semiconductor substrate 1 , and causing the modified region including the molten processed region to form a starting point region for cutting; and grinding a rear face 21 of the semiconductor substrate 1 after the step of forming the starting point region for cutting such that the semiconductor substrate 1 attains a predetermined thickness.

First claim

The invention claimed is:

1. A method of manufacturing a semiconductor device formed using a substrate dividing method, the manufacturing method comprising the steps of:
irradiating a laser light incident face of a substrate, the substrate comprising semiconductor material and having a surface formed with at least one semiconductor device, with laser light while positioning a light-converging point within the substrate, thereby forming a molten processed region embedded within the substrate along each line of a plurality of cutting lines arranged in a grid with respect to the substrate, the substrate having a front face and a rear face through the substrate, the front face of the substrate being formed with at least one functional device, the forming of each molten processed region resulting in the forming of a starting point region configured for cutting the substrate, and each molten processed region being located inside the substrate at a predetermined distance from the laser light incident face of the substrate; and
grinding the rear face of the substrate after the forming of the starting point regions, thereby removing from the substrate at least a portion of the molten processed regions that were formed in the substrate; and
wherein the substrate is divided when a fracture generated in a thickness direction of the substrate and extending from each starting point region reaches the front face and the rear face of the substrate, thereby providing at least one manufactured semiconductor device.

2. A method of manufacturing a semiconductor device according claim 1 , wherein in the grinding, all of the molten processed regions that were formed in the substrate are eliminated from the substrate without leaving any molten processed regions remaining in the substrate.

3. A method of manufacturing a semiconductor device according to claim 1 , wherein when each molten processed region is formed in the substrate by the irradiating, the substrate is irradiated with the laser light under a condition with a peak power density of at least 1×10 (W/cm 2 ) at the light converging point and a pulse width of 1 μs or less.

4. A method of manufacturing a semiconductor device according to claim 1 , wherein the laser light incident face of the substrate is formed with a functional device.

5. A method of manufacturing a semiconductor device according to claim 1 , wherein the step of grinding the substrate includes a step of subjecting the rear face of the substrate to chemical etching.

6. A method of manufacturing a semiconductor device according to claim 1 , wherein the substrate is divided into a plurality of chips along the cutting lines.

7. A method of manufacturing a semiconductor device according to claim 1 , wherein the substrate is divided when each fracture reaches the front face and the rear face of the substrate after the step of grinding.

8. A method of manufacturing a semiconductor device according to claim 1 , wherein the substrate is divided when each fracture reaches the front face and the rear face of the substrate in the step of grinding the substrate.

9. A method of manufacturing a semiconductor device according to claim 1 , wherein opposing fracture surfaces resulting from the generating of each fracture extending from each molten processed region are in contact with each other during the grinding.

10. A method of manufacturing a semiconductor device according to claim 1 , further comprising expanding a tape attached to the rear face of the substrate, after the grinding, to make space between adjacent chips formed in the substrate.

11. A method of manufacturing a semiconductor device according to claim 1 , further comprising attaching a tape to the rear face of the substrate after the grinding.

12. A method of manufacturing a semiconductor device according to claim 1 , wherein at the completion of the grinding, each fracture reaches the front face and the rear face of the substrate to divide the substrate.

13. A method of manufacturing a semiconductor device formed using a substrate dividing method, the manufacturing method comprising the steps of:
irradiating a laser light incident face of a substrate, the substrate comprising semiconductor material and having a surface formed with at least one semiconductor device, with laser light while positioning a light-converging point within the substrate, thereby forming a refractive index change region embedded within the substrate along each line of a plurality of cutting lines arranged in a grid with respect to the substrate, the substrate having a front face and a rear face through the substrate, the front face of the substrate being formed with at least one functional device, the forming of each refractive index change region resulting in the forming of a starting point region configured for cutting the substrate, each refractive index change region being located inside the substrate at a predetermined distance from the laser light incident face of the substrate, and the refractive index change region being formed by inducing a permanent structural change in an ionic valence change, crystallization or polarization orientation thereof within the substrate; and
grinding the rear face of the substrate after the forming of the starting point regions, thereby removing from the substrate at least a portion of the refractive index change regions that were formed in the substrate; and
wherein the substrate is divided when a fracture generated in a thickness direction of the substrate and extending from each starting point region reaches the front face and the rear face of the substrate, thereby providing at least one manufactured semiconductor device.

14. A method of manufacturing a semiconductor device according claim 13 , wherein in the grinding, all of the refractive index change regions that were formed in the substrate are eliminated from the substrate without leaving any refractive index changing regions remaining in the substrate.

15. A method of manufacturing a semiconductor device according to claim 13 , wherein the laser light incident face of the substrate is formed with a functional device.

16. A method of manufacturing a semiconductor device according to claim 13 , wherein the step of grinding the substrate includes a step of subjecting the rear face of the substrate to chemical etching.

17. A method of manufacturing a semiconductor device accruing to claim 13 , wherein when each refractive index change region is formed in the substrate by the irradiating, the substrate is irradiated with the laser light under a condition with a peak power density of at least 1×10 8 (W/cm 2 ) at the light-converging point and a pulse width of 1 ns or less.

18. A method of manufacturing a semiconductor device according to claim 13 , wherein the substrate is divided into a plurality of chips along the cutting lines.

19. A method of manufacturing a semiconductor device according to claim 13 , wherein the substrate is divided when each fracture reaches the front face and the rear face of the substrate after the step of grinding.

20. A method of manufacturing a semiconductor device according to claim 13 , wherein the substrate is divided when each fracture reaches the front face and the rear face of the substrate in the step of grinding the substrate.

21. A method of manufacturing a semiconductor device according to claim 13 , wherein opposing fracture surfaces resulting from the generating of each fracture extending from each refractive index change region are in contact with

Assignees

• Hamamatsu Photonics Kk

Inventors

• Fujii Yoshimaro
• Fukuyo Fumitsugu
• Fukumitsu Kenshi
• Uchiyama Naoki

Classifications

• H10P72/7416

  used during dicing or grinding · CPC title

• H10P72/742

  involving stretching of the auxiliary support post dicing · CPC title

• H10P72/7402

  Wafer tapes, e.g. grinding or dicing support tapes · CPC title

• H10P52/00

  Grinding, lapping or polishing of wafers, substrates or parts of devices · CPC title

• H10P50/642

  Chemical etching · CPC title