Crystallization processing for semiconductor applications

Patent metadata

Field	Value
Publication number	US-9290858-B2
Application number	US-201414495533-A
Country	US
Kind code	B2
Filing date	Sep 24, 2014
Priority date	Nov 30, 2009
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A method and apparatus for forming a crystalline semiconductor layer on a substrate are provided. A semiconductor layer is formed by vapor deposition. A pulsed laser melt/recrystallization process is performed to convert the semiconductor layer to a crystalline layer. Laser, or other electromagnetic radiation, pulses are formed into a pulse train and uniformly distributed over a treatment zone, and successive neighboring treatment zones are exposed to the pulse train to progressively convert the deposited material to crystalline material.

First claim

What is claimed is:

1. A method of treating a substrate, comprising:
identifying a first treatment zone;
forming a molten area of the first treatment zone by exposing a surface of the first treatment zone to a first laser pulse, wherein the first laser pulse has a non-uniformity of less than about 5 percent;
recrystallizing the molten area of the first treatment zone while exposing the first treatment zone to a first plurality of laser pulses;
identifying a second treatment zone;
forming a molten area of the second treatment zone by exposing a surface of the second treatment zone to a second laser pulse, wherein the second laser pulse has a non-uniformity of less than about 5 percent; and
recrystallizing the molten area of the second treatment zone while exposing the second treatment zone to a second plurality of laser pulses.

2. The method of claim 1 , wherein the forming a molten area of each treatment zone further comprises exposing the surface of each treatment zone to a third laser pulse, and a duration between the first laser pulse or second laser pulse and the third laser pulse is less than a time necessary for a portion of the molten area to refreeze.

3. The method of claim 2 , wherein the first laser pulse and the third laser pulse have the same duration and intensity.

4. The method of claim 1 , wherein each pulse of the first plurality of laser pulses has the same duration and intensity as the first laser pulse.

5. The method of claim 1 , wherein each pulse of the first plurality of laser pulses has a duration or an intensity that is different from the first laser pulse.

6. The method of claim 5 , wherein the forming a molten area of each treatment zone further comprises exposing the surface of each treatment zone to a third laser pulse, and a duration between the first laser pulse and the third laser pulse is less than a time necessary for a portion of the molten area to refreeze.

7. The method of claim 1 , wherein the second treatment zone and the first treatment zone share a boundary.

8. The method of claim 1 , wherein a duration between each pulse of the second plurality of laser pulses is more than a time to freeze the portion of the first treatment zone.

9. The method of claim 1 , wherein each pulse of the first and second plurality of laser pulses melts a portion of a recrystallized area.

10. The method of claim 1 , wherein the second treatment zone is adjacent to the first treatment zone.

11. The method of claim 1 , wherein each pulse of the first and second plurality of laser pulses melts a portion of a recrystallized area and the second treatment zone is adjacent to the first treatment zone.

12. A method of treating a substrate, comprising:
identifying a first treatment zone;
forming a molten area of the first treatment zone by exposing a surface of the first treatment zone to a first group of one or more laser pulses and a second group of one or more laser pulses;
recrystallizing the molten area of the first treatment zone while exposing the first treatment zone to a third group of one or more laser pulses, wherein a power delivered by the third group of one or more laser pulses is less than a power delivered by the first group of one or more laser pulses and a power delivered by the second group of one or more laser pulses;
identifying a second treatment zone; and
repeating the forming a molten area and the recrystallizing the molten area with the second treatment zone.

13. The method of claim 12 , wherein first group of one or more laser pulses are separated from the second group of one or more laser pulses by a rest duration, wherein the rest duration allows partial refreezing of the molten area before a subsequent pulse arrives.

14. The method of claim 12 , wherein the first group of one or more pulses is one pulse, the second group of one or more pulses comprises multiple pulses and the third group of one or more pulses comprises multiple pulses, wherein a power delivered by the second group of one or more pulses is higher than that delivered by the first group of one or more pulses.

15. The method of claim 14 , wherein the multiple pulses of the second group of one or more pulses overlap in time, and wherein the multiple pulses of the third group of one or more pulses are separated by a rest duration.

16. The method of claim 15 , wherein the second treatment zone is adjacent to the first treatment zone.

17. A method of treating a substrate, comprising:
identifying a first treatment zone;
forming a molten area of the first treatment zone by exposing a surface of the first treatment zone to a first plurality of laser pulses;
recrystallizing the molten area of the first treatment zone while exposing the first treatment zone to a second plurality of laser pulses, wherein each pulse of the second plurality of laser pulses melts a portion of a recrystallized area;
identifying a second treatment zone; and
repeating the forming a molten area and the recrystallizing the molten area with the second treatment zone.

18. The method of claim 17 , wherein each pulse of the first plurality of laser pulses has a duration between about 1 ns and about 50 ns.

19. The method of claim 18 , wherein the second treatment zone is adjacent to the first treatment zone.

20. The method of claim 17 , wherein each pulse of the first plurality of laser pulses delivers a power between about 10 7 W/cm 2 and about 10 9 W/cm 2 .

Assignees

• Applied Materials Inc

Inventors

• Moffatt Stephen

Classifications

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P34/42

  with electromagnetic radiation, e.g. laser annealing (laser cutting H10P54/20) · CPC title

• H10P14/3436

  being chalcogenide semiconductor materials not being oxides, e.g. ternary compounds · CPC title

• H10P14/3411 Primary

  Silicon, silicon germanium or germanium · CPC title

• H10P14/3816 Primary

  Pulsed laser beam · CPC title