Crystallization processing for semiconductor applications

Patent metadata

Field	Value
Publication number	US-9455145-B2
Application number	US-201615016328-A
Country	US
Kind code	B2
Filing date	Feb 5, 2016
Priority date	Nov 30, 2009
Publication date	Sep 27, 2016
Grant date	Sep 27, 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, comprising:
forming a semiconductor layer on a crystalline substrate;
melting a portion of the semiconductor layer by exposing the semiconductor layer to a plurality of energy pulses, wherein the plurality of energy pulses melts the portion of the semiconductor layer to reach a melt end point a distance from an interface between the semiconductor layer and the crystalline substrate, wherein a buffer layer is defined between the melt end point and the interface;
crystallizing the buffer layer by exposing the semiconductor layer to a first group of one or more energy pulses distinct from the plurality of energy pulses, wherein a crystal structure of the buffer layer is formed; and
crystallizing the melted portion of the semiconductor layer by the first group of one or more energy pulses, wherein a crystal structure of the melted portion of the semiconductor layer is developed from the crystal structure of the buffer layer.

2. The method of claim 1 , wherein the plurality of energy pulses includes a second group of one or more energy pulses and a third group of one or more energy pulses.

3. The method of claim 2 , wherein a power delivered by the third group of one or more energy pulses is higher than a power delivered by the second group of one or more energy pulses.

4. The method of claim 2 , wherein a power delivered by the first group of one or more energy pulses is less than a power delivered by the second group of one or more energy pulses.

5. The method of claim 2 , wherein the second group of one or more energy pulses is separated from the third group of one or more energy pulses by a rest duration.

6. The method of claim 5 , wherein the rest duration allows partial refreezing of the melted portion of the semiconductor layer.

7. The method of claim 1 , wherein the semiconductor layer is doped.

8. A method of treating a substrate, comprising:
forming a semiconductor layer on a crystalline substrate;
identifying a first treatment zone on the semiconductor layer;
melting a portion of the semiconductor layer by exposing the first treatment zone of the semiconductor layer to a plurality of energy pulses, wherein the plurality of energy pulses melts the portion of the semiconductor layer to reach a melt end point a distance from an interface between the semiconductor layer and the crystalline substrate, wherein a buffer layer is defined between the melt end point and the interface;
crystallizing a portion of the buffer layer by exposing the first treatment zone of the semiconductor layer to a first group of one or more energy pulses distinct from the plurality of energy pulses, wherein a crystal structure of the portion of the buffer layer is formed;
crystallizing the melted portion of the first treatment zone of the semiconductor layer by the first group of one or more energy pulses, wherein a crystal structure of the melted portion of the semiconductor layer is developed from the crystal structure of the portion of the buffer layer;
identifying a second treatment zone; and
repeating melting a portion of the semiconductor layer, crystallizing a portion of the buffer layer and crystallizing the melted portion of the second treatment zone.

9. The method of claim 8 , wherein the plurality of energy pulses includes a second group of one or more energy pulses and a third group of one or more energy pulses.

10. The method of claim 9 , wherein a power delivered by the third group of one or more energy pulses is higher than a power delivered by the second group of one or more energy pulses.

11. The method of claim 9 , wherein a power delivered by the first group of one or more energy pulses is less than a power delivered by the third group of one or more energy pulses.

12. The method of claim 9 , wherein a power delivered by the first group of one or more energy pulses is less than a power delivered by the second group of one or more energy pulses.

13. The method of claim 9 , wherein the second group of one or more energy pulses is separated from the third group of one or more energy pulses by a rest duration.

14. The method of claim 13 , wherein the rest duration allows partial refreezing of the melted portion of the semiconductor layer.

15. A method, comprising:
forming a semiconductor layer on a crystalline substrate;
melting a portion of the semiconductor layer by exposing the semiconductor layer to a plurality of energy pulses, wherein the plurality of energy pulses melts the portion of the semiconductor layer to reach a melt end point a distance from an interface between the semiconductor layer and the crystalline substrate, wherein the plurality of energy pulses includes a first energy pulse at a first intensity and a first group of one or more energy pulses at a second intensity greater than the first intensity, wherein a buffer layer is defined between the melt end point and the interface;
crystallizing the buffer layer by exposing the semiconductor layer to a second group of one or more energy pulses distinct from the plurality of energy pulses, wherein a crystal structure of the buffer layer is formed; and
crystallizing the melted portion of the semiconductor layer by the first group of one or more energy pulses, wherein a crystal structure of the melted portion of the semiconductor layer is developed from the crystal structure of the buffer layer.

16. The method of claim 15 , wherein the second group of one or more energy pulses each has a third intensity less than the second intensity.

17. The method of claim 15 , wherein the second group of one or more energy pulses each has a third intensity less than the first intensity.

18. The method of claim 15 , wherein the first energy pulse is separated from the first group of one or more energy pulses by a rest duration.

19. The method of claim 18 , wherein the rest duration allows partial refreezing of the melted portion of the semiconductor layer.

20. The method of claim 15 , wherein the first group of one or more energy pulses includes 10 energy pulses.

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