Method for guiding a crack in the peripheral region of a donor substrate

Patent metadata

Field	Value
Publication number	US-10676386-B2
Application number	US-201916360182-A
Country	US
Kind code	B2
Filing date	Mar 21, 2019
Priority date	Jun 23, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

The present invention relates to a method for separating solid-body slices (1) from a donor substrate (2). The method comprises the steps of: producing modifications (10) within the donor substrate (2) by means of laser beams (12), wherein a detachment region is predefined by the modifications (10), along which detachment region the solid-body layer (1) is separated from the donor substrate (2), and removing material from the donor substrate (2), starting from a surface (4) extending in the peripheral direction of the donor substrate (2), in the direction of the centre (Z) of the donor substrate (2), in particular in order to produce a peripheral indentation (6).

First claim

The invention claimed is:

1. A method for separating a solid-body layer from a substrate, the method comprising:
producing modifications within the substrate using a laser device, the modifications defining a detachment region within the substrate that is weakened by the modifications, the modifications being produced within the substrate at a distance from a delimiting edge of the substrate;
arranging a stress-inducing layer on a surface of the substrate;
thermally treating the stress-inducing layer so as to produce mechanical stress in the substrate, the mechanical stress creating a crack which propagates in a targeted manner in a region of crack formation predefined by the modifications;
removing material from the delimiting edge of the substrate up to the detachment region, or beneath or above the detachment region; and
separating the solid-body layer from the substrate along the crack.

2. The method of claim 1 , wherein thermally treating the stress-inducing layer comprises cooling the stress-inducing layer.

3. The method of claim 1 , further comprising:
forming an indentation in a delimiting edge of the substrate,
wherein an end of the indentation is adjacent to the region of crack formation predefined by the modifications.

4. The method of claim 3 , wherein forming the indentation comprises:
applying a grinding tool to the delimiting edge of the substrate, the grinding tool comprising a first processing portion having a curved main grinding face and a second processing portion having a curved secondary grinding face,
wherein the radius of the main grinding face is greater than the radius of the secondary grinding face.

5. The method of claim 3 , wherein forming the indentation comprises:
applying a grinding tool to the delimiting edge of the substrate, the grinding tool comprising a first processing portion having a straight main grinding face and a second processing portion having a straight secondary grinding face,
wherein more material is removed from the delimiting edge of the substrate by the main grinding face than by the secondary grinding face.

6. The method of claim 3 , wherein forming the indentation comprises:
directing one or more ablation laser beams at the delimiting edge of the substrate to evaporate material of the substrate and produce the indentation.

7. The method of claim 6 , wherein the surface of the substrate meets the delimiting edge of the substrate without a change in planarity.

8. The method of claim 6 , wherein the indentation is symmetrical about the end of the indentation.

9. The method of claim 3 , wherein the stress-inducing layer covers or closes the indentation.

10. The method of claim 3 , wherein the indentation extends from the surface of the substrate on which the stress-inducing layer is arranged to the modifications.

11. The method of claim 3 , wherein the stress-inducing layer is a polymer layer, and wherein the polymer layer is the only material accumulated in the indentation.

12. A method for separating a solid-body layer from a substrate, the method comprising:
forming an indentation in a delimiting edge of the substrate;
producing modifications within the substrate using a laser device, the modifications defining a detachment region within the substrate that is weakened by the modifications and aligned with the indentation; and
detaching the solid-body layer from the substrate along the detachment region,
wherein the modifications are produced at a distance from the delimiting edge of the substrate to an extent such that laser beam portions emitted from the laser device are each refracted through material with a same refractive index.

13. The method of claim 12 , wherein the laser beam portions emitted from the laser device are each refracted through the material over a same distance.

14. The method of claim 12 ,
wherein an end of the indentation is adjacent to the region of crack formation predefined by the modifications.

15. The method of claim 14 , wherein forming the indentation comprises:
applying a grinding tool to the delimiting edge of the substrate, the grinding tool comprising a first processing portion having a curved main grinding face and a second processing portion having a curved secondary grinding face,
wherein the radius of the main grinding face is greater than the radius of the secondary grinding face.

16. The method of claim 14 , wherein forming the indentation comprises:
applying a grinding tool to the delimiting edge of the substrate, the grinding tool comprising a first processing portion having a straight main grinding face and a second processing portion having a straight secondary grinding face,
wherein more material is removed from the delimiting edge of the substrate by the main grinding face than by the secondary grinding face.

17. The method of claim 14 , wherein forming the indentation comprises:
directing one or more ablation laser beams at the delimiting edge of the substrate to evaporate material of the substrate and produce the indentation.

Assignees

• Siltectra Gmbh

Inventors

• Swoboda Marko
• Beyer Christian
• Schilling Franz
• Richter Jan

Classifications

• B23K2101/40

  Semiconductor devices · CPC title

• B23K26/359

  by providing a line or line pattern, e.g. a dotted break initiation line · CPC title

• B23K26/0006

  taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence) · CPC title

• H01L21/304

  Electricity · mapped topic

• C03B33/0222 Primary

  Scoring using a focussed radiation beam, e.g. laser · CPC title