Laser irradiation method and laser irradiation apparatus

Patent metadata

Field	Value
Publication number	US-10369658-B2
Application number	US-201615202022-A
Country	US
Kind code	B2
Filing date	Jul 5, 2016
Priority date	May 14, 2004
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

The present invention is to provide a laser irradiation technique for irradiating the irradiation surface with the laser beam having homogeneous intensity distribution using a cylindrical lens array without being affected by the intensity distribution of the original beam. A laser beam emitted from a laser oscillator is divided by two kinds of cylindrical lens arrays into a plurality of beams, which are two kinds of linear laser beams with their energy intensity distribution inverted each other, and the two kinds of linear laser beams are superposed in a minor-axis direction. This can form the linear laser beam having homogeneous intensity distribution on the irradiation surface.

First claim

What is claimed is:

1. A method for manufacturing a semiconductor device comprising:
forming a semiconductor layer comprising amorphous silicon over a substrate;
emitting a laser beam from a laser oscillator;
shaping the laser beam by at least a lens array arranged in a matrix of rows and columns to form a plurality of laser beams; and
irradiating the semiconductor layer with the plurality of laser beams to crystallize the semiconductor layer,
wherein the lens array comprises a plurality of first cylindrical lenses in a first row,
wherein the lens array comprises a plurality of second cylindrical lenses in a second row,
wherein the plurality of first cylindrical lenses is directly connected to the plurality of second cylindrical lenses,
wherein the first cylindrical lens in a first column is directly connected to the first cylindrical lens in a second column,
wherein the second cylindrical lens in the first column is directly connected to the second cylindrical lens in the second column,
wherein the first cylindrical lens in the first column is adjacent to the first cylindrical lens in the second column in a first direction,
wherein the first cylindrical lens in the first column is adjacent to the second cylindrical lens in the first column in a second direction,
wherein the first direction is perpendicular to the second direction,
wherein the second direction is parallel to a direction of a generating line of the first cylindrical lens in the first column, and
wherein the laser beam enters the lens array from a direction perpendicular to the first direction and the second direction.

2. The method according to claim 1 , wherein each of the plurality of laser beams is an excimer laser.

3. The method according to claim 1 , wherein each of the plurality of laser beams is a harmonic wave of a YAG laser.

4. The method according to claim 1 , wherein each of the plurality of laser beams is a harmonic wave of a YVO 4 laser.

5. The method according to claim 1 , further comprising a step of superposing the plurality of laser beams on a surface of the semiconductor layer.

6. The method according to claim 1 , further comprising a step of patterning the semiconductor layer.

7. The method according to claim 1 , wherein the lens array comprises a plurality of cylindrical lenses.

8. The method according to claim 1 , wherein the lens array comprises a plurality of convex lenses.

9. The method according to claim 1 , wherein the semiconductor device is at least one selected from the group consisting of a display device, a computer and a mobile phone.

10. A method for manufacturing a semiconductor device comprising:
forming a semiconductor layer comprising amorphous silicon over a substrate;
emitting a laser beam from a laser oscillator;
shaping the laser beam by at least a lens array arranged in a matrix of rows and columns to form a plurality of laser beams;
irradiating the semiconductor layer with the plurality of laser beams to crystallize the semiconductor layer; and
moving the substrate relative to the plurality of laser beams during irradiation with the plurality of laser beams,
wherein the lens array comprises a plurality of first cylindrical lenses in a first row,
wherein the lens array comprises a plurality of second cylindrical lenses in a second row,
wherein the plurality of first cylindrical lenses is directly connected to the plurality of second cylindrical lenses,
wherein the first cylindrical lens in a first column is directly connected to the first cylindrical lens in a second column,
wherein the second cylindrical lens in the first column is directly connected to the second cylindrical lens in the second column,
wherein the first cylindrical lens in the first column is adjacent to the first cylindrical lens in the second column in a first direction,
wherein the first cylindrical lens in the first column is adjacent to the second cylindrical lens in the first column in a second direction,
wherein the first direction is perpendicular to the second direction,
wherein the second direction is parallel to a direction of a generating line of the first cylindrical lens in the first column, and
wherein the laser beam enters the lens array from a direction perpendicular to the first direction and the second direction.

11. The method according to claim 10 , wherein each of the plurality of laser beams is an excimer laser.

12. The method according to claim 10 , wherein each of the plurality of laser beams is a harmonic wave of a YAG laser.

13. The method according to claim 10 , wherein each of the plurality of laser beams is a harmonic wave of a YVO 4 laser.

14. The method according to claim 10 , further comprising a step of superposing the plurality of laser beams on a surface of the semiconductor layer.

15. The method according to claim 10 , further comprising a step of patterning the semiconductor layer.

16. The method according to claim 10 , wherein the lens array comprises a plurality of cylindrical lenses.

17. The method according to claim 10 , wherein the lens array comprises a plurality of convex lenses.

18. The method according to claim 10 , wherein the semiconductor device is at least one selected from the group consisting of a display device, a computer and a mobile phone.

Assignees

• Semiconductor Energy Lab

Inventors

• Tanaka Koichiro
• Oishi Hirotada

Classifications

• B23K2103/56

  being semiconducting · CPC title

• G02B27/0927

  Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat · CPC title

• B23K26/0608 Primary

  in the same heat affected zone [HAZ] (B23K26/0613, B23K26/0619 take precedence) · CPC title

• B23K15/10

  Non-vacuum electron beam-welding or cutting · CPC title

• B23K26/0732

  into a rectangular shape · CPC title