Method for dicing substrate

• US 20050272223A1
• Filed: 03/06/2003
• Published: 12/08/2005
• Est. Priority Date: 03/12/2002
• Status: Active Grant

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Uchiyama, Naoki, Fujii, Yoshimaro, Fukumitsu, Kenshi, Fukuyo, Fumitsugu
• Granted Patent: US 8,268,704 B2
• Time in Patent Office: Days
• US Class Current: 438/459
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: B23K 26/53 for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks
• CPC Class Codes: B28D 5/00 Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor working by grinding or polishing B24; for artistic purposes B44B
• CPC Class Codes: B28D 5/0011 with preliminary treatment, e.g. weakening by scoring
• CPC Class Codes: H01L 21/268 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 21/304 Mechanical treatment, e.g. grinding, polishing, cutting H01L21/30625 takes precedence
• CPC Class Codes: H01L 21/30604 Chemical etching
• 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 21/76894 using a laser, e.g. laser cutting, laser direct writing, laser repair
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H01L 2221/68327 used during dicing or grinding
• CPC Class Codes: H01L 2221/68336 involving stretching of the auxiliary support post dicing
• CPC Class Codes: H01L 2223/5446 Located in scribe lines
• CPC Class Codes: H01L 23/544 Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps test patterns for characterising or monitoring manufacturing processes H01L22/00
• CPC Class Codes: H01L 23/562 Protection against mechanical damage H01L23/02, H01L23/28 take precedence
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

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.

Claims

1-12. -12. (canceled)

13. A substrate dividing method comprising the steps of:

irradiating a substrate with laser light while positioning a light-converging point within the substrate, so as to form a modified region due to multiphoton absorption within the substrate, and causing the modified region to form a starting point region for cutting along a line along which the substrate should be cut in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

14. A substrate dividing method according to claim 13, wherein the substrate is a semiconductor substrate.

15. A substrate dividing method according to claim 14, wherein the modified region is a molten processed region.

16. A substrate dividing method according to claim 13, wherein the substrate is an insulating substrate.

17. A substrate dividing method according to any one of claims 13-16, wherein a front face of the substrate is formed with a functional device;

and

wherein a rear face of the substrate is ground in the step of grinding the substrate.

18. A substrate dividing method according to claim 17, wherein the step of grinding the substrate includes a step of subjecting the rear face of the substrate to chemical etching.

19. A substrate dividing method comprising the steps of:

irradiating a substrate with laser light while positioning a light-converging point within the substrate under a condition with a peak power density of at least 1×

10⁸ (W/cm²) at the light-converging point and a pulse width of 1 μ

s or less, so as to form a modified region including a crack region within the substrate, and causing the modified region to form a starting point region for cutting along a line along which the substrate should be cut in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

20. A substrate dividing method comprising the steps of:

irradiating a substrate with laser light while positioning a light-converging point within the substrate under a condition with a peak power density of at least 1×

10⁸ (W/cm²) at the light-converging point and a pulse width of 1 μ

s or less, so as to form a modified region including a molten processed region within the substrate, and causing the modified region to form a starting point region for cutting along a line along which the substrate should be cut in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

21. A substrate dividing method comprising the steps of:

irradiating a substrate with laser light while positioning a light-converging point within the substrate under a condition with a peak power density of at least 1×

10⁸ (W/cm²) at the light-converging point and a pulse width of 1 ns or less, so as to form a modified region including a refractive index change region which is a region with a changed refractive index within the substrate, and causing the modified region to form a starting point region for cutting along a line along which the substrate should be cut in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

22. A substrate dividing method comprising the steps of:

irradiating a substrate which is made of a semiconductor material with laser light while positioning a light-converging point within the substrate under a condition with a peak power density of at least 1×

10⁸ (W/cm²) at the light-converging point and a pulse width of 1 μ

s or less, so as to form a modified region within the substrate, and causing the modified region to form a starting point region for cutting along a line along which the substrate should be cut in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

23. A substrate dividing method comprising the steps of:

irradiating a substrate which is made of a piezoelectric material with laser light while positioning a light-converging point within the substrate under a condition with a peak power density of at least 1×

10⁸ (W/cm²) at the light-converging point and a pulse width of 1 μ

s or less, so as to form a modified region with the substrate, and causing the modified region to form a starting point region for cutting along a line along which the substrate should be cut in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

24. A substrate dividing method comprising the steps of:

irradiating a substrate which is made of a semiconductor material with laser light while positioning a light-converging point within the substrate, so as to form a molten processed region within the substrate, and causing the molten processed region to form a starting point region for cutting along a line along which the substrate should be cut in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

25. A substrate dividing method comprising the steps of:

irradiating a substrate with laser light while positioning a light-converging point within the substrate, so as to form a modified region due to multiphoton absorption within the substrate, and causing the modified region to form a starting point region for cutting along each line along which the substrate should be cut and the lines being arranged in a lattice for the substrate, in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness, so as to divide the substrate into a plurality of chips along the lines along which the substrate should be cut.

26. A substrate dividing method comprising the steps of:

irradiating a substrate made of a semiconductor material with laser light while positioning a light-converging point within the substrate, so as to form a molten processed region within the substrate, and causing the molten processed region to form a starting point region for cutting along a line along which the substrate should be cut, in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness.

27. A substrate dividing method comprising the steps of:

irradiating a substrate made of a semiconductor material with laser light while positioning a light-converging point within the substrate, so as to form a molten processed region within the substrate, and causing the molten processed region to form a starting point region for cutting along each line along which the substrate should be cut and the lines being arranged in a lattice for the substrate, in the substrate inside by a predetermined distance from a laser light incident face of the substrate; and

grinding the substrate after the step of forming the starting point region for cutting such that the substrate attains a predetermined thickness, so as to divide the substrate into a plurality of chips along the lines along which the substrate should be cut.