Substrate dividing method

Patent metadata

Field	Value
Publication number	US-2016343618-A1
Application number	US-201615226417-A
Country	US
Kind code	A1
Filing date	Aug 2, 2016
Priority date	Mar 12, 2002
Publication date	Nov 24, 2016
Grant date	—

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

1 - 6 . (canceled)

7 : A semiconductor chip manufacturing method, wherein a semiconductor substrate having a plurality of circuit devices formed in matrix on a front face of the semiconductor substrate is divided into the circuit devices to obtain semiconductor chips, 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 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 without the molten processed region intersecting the front face of the substrate; and grinding the rear face of the substrate after the step of forming the starting point regions, thereby eliminating all of the molten processed regions from the substrate without leaving any of the molten processed regions in the substrate, wherein the substrate comprises at least a portion of a fracture generated in a thickness direction of the substrate from each starting point region after completion of the grinding step; and wherein the substrate is divided when each fracture reaches the front face and the rear face of the substrate, thereby providing at least one semiconductor chip including one of the circuit devices.

8 : A semiconductor chip manufacturing method according to claim 7 , 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 8 (W/cm 2 ) at the light converging point and a pulse width of 1 μs or less.

9 : A semiconductor chip manufacturing method according to claim 7 , wherein the laser light incident face of the substrate is formed with one of the circuit devices.

10 : A semiconductor chip manufacturing method according to claim 7 , wherein the grinding step includes subjecting the rear face of the substrate to chemical etching.

11 : A semiconductor chip manufacturing method according to claim 7 , wherein opposing fracture surfaces resulting from the generating of each fracture from the molten processed region are in contact with each other during the grinding.

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

13 : A semiconductor chip manufacturing method according to claim 7 , 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.

14 : A semiconductor chip manufacturing method according to claim 7 , 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.

15 : A semiconductor chip manufacturing method according to claim 7 , further comprising attaching a tape to the rear face of the substrate after the grinding.

16 : A semiconductor chip manufacturing method according to claim 7 , wherein at the completion of the grinding, each fracture reaches the front face and the rear face of the substrate to divide the substrate.

17 : A semiconductor chip manufacturing method, wherein a semiconductor substrate having a plurality of circuit devices formed in matrix on a front face of the semiconductor substrate is divided into the circuit devices to obtain semiconductor chips, 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 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 without the refractive index change region intersecting the front face of the substrate, and the refractive index change region being formed by inducing an ionic valence change, crystallization or polarization orientation within the substrate; and grinding the rear face of the substrate after the step of forming the starting point regions, thereby eliminating all of the refractive index change regions from the substrate without leaving any of the refractive index change regions in the substrate, wherein the substrate comprises at least a portion of a fracture generated in a thickness direction of the substrate from each starting point region after completion of the grinding step; and wherein the substrate is divided when each fracture reaches the front face and the rear face of the substrate, thereby providing at least one semiconductor chip including one of the circuit devices.

18 : A semiconductor chip manufacturing method according to claim 17 , wherein the laser light incident face of the substrate is formed with one of the circuit devices.

19 : A semiconductor chip manufacturing method according to claim 17 , wherein the grinding step includes a step of subjecting the rear face of the substrate to chemical etching.

20 : A semiconductor chip manufacturing method of according to claim 17 , 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.

21 : A semiconductor chip manufacturing method according to claim 17 , wherein opposing fracture surfaces resulting from the generating of each fracture extending from each refractive index change region are in contact with each other during the grinding.

22 : A semiconductor chip manufacturing method according to claim 17 , wherein the substrate is divided when each fracture reaches the front face and the rear face of the substrate after the step of grinding.

23 : A semiconductor chip manufacturing method according to claim 17 , 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.

24 : A semiconductor chip manufacturing method according to claim 17 , 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.

25 : A semiconductor chip manufacturing

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