# US 7,611,970 B2 · Wafer processing method

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,611,970 B2
- Document ID: US7611970B2
- Status: Granted
- Kind: B2
- Application number: 11/907,939
- Filed: 2007-10-18
- Published: 2008-04-24
- Granted: 2009-11-03
- Earliest claimed: 2006-10-23
- Assignees: Disco Corporation
- Inventors: Toshiyuki Sakai
- Web page: https://patentgrep.com/patent/US7611970B2

## CPC

- H10P 36/03: {within silicon bodies}
- B23K 26/40: taking account of the properties of the material involved
- B23K 26/53: for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks
- B23K 26/57: the laser beam entering a face of the workpiece from which it is transmitted through the workpiece material to work on a different workpiece face, e.g. for effecting removal, fusion splicing, modifying or reforming
- H10P 34/42: with electromagnetic radiation, e.g. laser annealing (laser cutting H10P54/20)
- H10P 52/00: Grinding, lapping or polishing of wafers, substrates or parts of devices
- H10P 54/00: Cutting or separating of wafers, substrates or parts of devices
- H10P 72/0428: {Apparatus for mechanical treatment or grinding or cutting}
- B23K 2103/50: {Inorganic materials other than metals or composite materials}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM

## Abstract

A water processing method for providing a gettering sink effect to a wafer having a plurality of streets which are formed in a lattice pattern on the front surface of a substrate and devices which are formed in a plurality of areas sectioned by the plurality of streets, comprising the steps of removing distortion produced on the rear surface of the substrate of the wafer whose rear surface of the substrate has been ground to a predetermined thickness; forming a gettering sink effect layer by applying a laser beam of a wavelength having permeability for the substrate of the wafer which has undergone the distortion removing step, with its focal point set to the inside of the substrate to form a deteriorated layer in the inside of the substrate; and dividing the wafer which has undergone the gettering sink effect layer forming step, into individual chips along the streets.

## Claims

### Claim 1

A water processing method for providing a gettering sink effect to a wafer having a plurality of streets which are formed in a lattice pattern on the front surface of a substrate and devices which are formed in a plurality of areas sectioned by the plurality of streets, comprising:
a grinding distortion layer removing step for removing grinding distortion produced on the rear surface of the substrate of the wafer whose rear surface of the substrate has been ground to a predetermined thickness;
a gettering sink effect layer forming step for forming a gettering sink effect layer by applying a laser beam of a wavelength having permeability for the substrate of the wafer which has undergone the grinding distortion layer removing step, with its focal point set to the inside of the substrate to form a deteriorated layer in the inside of the substrate; and
a dividing step for dividing the wafer which has undergone the gettering sink effect layer forming step, into individual chips along the streets.

### Claim 2

A water processing method for providing a gettering sink effect to a wafer having a plurality of streets which are formed in a lattice pattern on the front surface of a substrate and devices which are formed in a plurality of areas sectioned by the plurality of streets, comprising:
a grinding distortion layer removing step for removing grinding distortion produced on the rear surface of the substrate of the wafer whose rear surface of the substrate has been ground to a predetermined thickness;
a dividing step for dividing the wafer which has undergone the grinding distortion layer removing step, into individual chips along the streets; and
a gettering sink effect layer forming step for forming a gettering sink effect layer by applying a laser beam of a wavelength having permeability for the substrate of the wafer which has been divided into individual chips by the dividing step, with its focal point set to the inside of the substrate of each chip to form a deteriorated layer in the inside of the substrate.