Method for producing a detachment area in a solid body

Patent metadata

Field	Value
Publication number	US-11527441-B2
Application number	US-202117174432-A
Country	US
Kind code	B2
Filing date	Feb 12, 2021
Priority date	Nov 27, 2014
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A method for producing a detachment area in a solid body in described. The solid body has a crystal lattice and is at least partially transparent to laser beams emitted by a laser. The method includes: modifying the crystal lattice of the solid by a laser beam, wherein the laser beam penetrates through a main surface of a detachable solid portion of the solid body, wherein a plurality of modifications are produced in the crystal lattice, wherein the modification are formed in a plane parallel to the main surface and at a distance from one another, wherein as a result of the modifications, the crystal lattice cracks the regions surrounding the modifications sub-critically in at least the one portion, and wherein the subcritical cracks are arranged in a plane parallel to the main surface.

First claim

The invention claimed is:

1. A method for producing a detachment region in a solid body, the method comprising:
providing the solid body having a crystal lattice and that is at least partially transparent to a laser beam emitted by a laser; and
modifying the crystal lattice of the solid body by the laser beam, wherein the laser beam penetrates through a main surface of a detachable solid portion of the solid body,
wherein a plurality of modifications are produced in the crystal lattice, wherein the plurality of modifications are formed in a plane parallel to the main surface and at a distance from one another,
wherein as a result of the plurality of modifications, the crystal lattice cracks sub- critically in regions surrounding the modifications,
wherein the subcritical cracks are arranged in a plane parallel to the main surface, a plurality of the subcritical cracks forming the detachment region in the solid body along which the solid body is separated into at least two components,
wherein the plurality of the subcritical cracks pass at least in some sections through a majority of the plurality of modifications.

2. The method of claim 1 , wherein the laser has a pulse spacing between 0.01 μm and 10 μm and a pulse repetition frequency between 16 kHz and 1024 kHz.

3. The method of claim 1 , wherein the plurality of the subcritical cracks combine to form a main crack through which the solid body is at least partially split.

4. The method of claim 1 , wherein:
the plurality of modifications are produced in a first section of the solid body such that a main crack is formed extending through a plurality of the sub-critical cracks;
after the formation of the main crack, further modifications are produced in at least one further section of the solid; and
the main crack is further guided through cracks in an area of the further modifications into the at least one further section of the solid.

5. The method of claim 1 , wherein the detachment region has more than one plane parallel to the main surface.

6. The method of claim 1 , wherein a centre of a first number of the plurality of modifications are on one side of the detachment region and a centre of a second number of the plurality of modifications are on an opposite side of the detachment region.

7. A method for producing a detachment region in a solid body, the method comprising:
providing the solid body having a crystal lattice and that is at least partially transparent to a laser beam emitted by a laser; and
modifying the crystal lattice of the solid body by the laser beam, wherein the laser beam penetrates through a main surface of a detachable solid portion of the solid body,
wherein a plurality of modifications are produced in the crystal lattice, wherein the plurality of modifications are formed in a plane parallel to the main surface and at a distance from one another,
wherein as a result of the plurality of modifications, the crystal lattice cracks sub-critically in regions surrounding the modifications, a plurality of the subcritical cracks forming the detachment region in the solid body along which the solid body is separated into at least two components,
wherein the subcritical cracks are arranged in a plane parallel to the main surface,
wherein a first number of the plurality of modifications are produced with a centre of the first number of modifications on one side of the detachment region and a second number of the plurality of modifications are produced with a centre of the second number of modifications on an opposite side of the detachment region.

8. A method for producing a detachment region in a solid body, the method comprising:
providing the solid body having a crystal lattice and that is at least partially transparent to a laser beam emitted by a laser; and
modifying the crystal lattice of the solid body by the laser beam, wherein the laser beam penetrates through a main surface of a detachable solid portion of the solid body,
wherein a plurality of modifications are produced in the crystal lattice, wherein the plurality of modifications are formed in a plane parallel to the main surface and at a distance from one another,
wherein as a result of the plurality of modifications, the crystal lattice cracks sub-critically in regions surrounding the modifications, a plurality of the subcritical cracks forming the detachment region in the solid body along which the solid body is separated into at least two components,
wherein the subcritical cracks are arranged in a plane parallel to the main surface,
wherein:
in at least two different regions of the solid body, tho a number of the plurality of modifications produced per cm2 is different;
a first block of modification lines is produced in a first region, each modification line of the first block of modification lines being produced spaced apart from another modification line of the first block of modification lines by less than 20 μm;
a first partial detachment region is formed by the first block of modification lines;
a second block of modification lines is produced in a second region, each modification line of the second block of modification lines being produced spaced apart from another modification line of the second block of modification lines by less than 20 μm;
a second partial detachment region is formed by the second block of modification lines;
the first partial detachment region and the second partial detachment region are spaced apart from one another by a third region;
in the third region, none or substantially none of the plurality of no modifications or fewer of the plurality of modifications per cm2 compared with the first partial detachment or second partial detachment region are produced by the laser beam; and
the first partial detachment region is spaced apart from the second partial detachment region by more than 20 μm.

9. The method of claim 8 , wherein the first block of modification lines are produced by the laser having a pulse spacing between 0.01 μm and 10 μm and a pulse repetition frequency between 16 kHz and 20 MHz.

10. The method of claim 8 , wherein the first partial detachment region and the second partial detachment region are in different planes parallel to the main surface.

11. The method of claim 8 , wherein a centre of the plurality of modifications of the first partial detachment region are on one side of the first partial detachment region, and a centre of the plurality of modifications of the second partial detachment region are on an opposite side of the second partial detachment region.

Assignees

• Siltectra Gmbh

Inventors

• Beyer Christian
• Richter Jan

Classifications

• H10P54/00 Primary

  Cutting or separating of wafers, substrates or parts of devices · CPC title

• H10P95/112 Primary

  leaving a reusable substrate, e.g. epitaxial lift off · CPC title

• B23K26/53 Primary

  for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks · CPC title

• B23K2101/40

  Semiconductor devices · CPC title

• B23K2103/56

  being semiconducting · CPC title