Crystallization processing for semiconductor applications

• US 8,691,605 B2
• Filed: 11/16/2012
• Issued: 04/08/2014
• Est. Priority Date: 11/30/2009
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Moffatt, Stephen
• Primary Examiner(s): Maldonado, Julio J
• Assistant Examiner(s): Shook, Daniel
• Application Number:
  US13/679,633
• Publication Number:
  US 20130143417A1
• Time in Patent Office: 508 Days
• Field of Search: 257/E21.347, 438/36, 438/89, 438/166, 438/797, 438/799
• US Class Current: 438/36
• CPC Class Codes: C30B 13/24 using electromagnetic waves
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02568 Chalcogenide semiconducting materials not being oxides, e.g. ternary compounds
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/2636 for heating, e.g. electron beam heating
• CPC Class Codes: H01L 21/268 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 29/685 Hi-Lo semiconductor devices, e.g. memory devices
• CPC Class Codes: H01L 31/1872 Recrystallisation
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

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.

Claims

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 and a second laser pulse, wherein the first laser pulse and the second laser pulse have the same duration and intensity;

recrystallizing the molten area of the first treatment zone while exposing the first treatment zone to a plurality of laser pulses, wherein each pulse of the plurality of laser pulses melts a portion of a recrystallized area;

identifying a second treatment zone adjacent to the first treatment zone; and

repeating the forming a molten area and the recrystallizing the molten area with the second treatment zone.

2. The method of claim 1, wherein a duration between the first laser pulse and the second laser pulse is less than a time necessary for a portion of the molten area to refreeze.

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

4. 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;

recrystallizing the molten area of the first treatment zone while exposing the first treatment zone to a plurality of laser pulses, wherein each pulse of the plurality of laser pulses melts a portion of a recrystallized area, wherein each pulse of the plurality of laser pulses has a duration or an intensity that is different from the first laser pulse;

identifying a second treatment zone adjacent to the first treatment zone; and

repeating the forming a molten area and the recrystallizing the molten area with the second treatment zone.

5. The method of claim 4, wherein the second treatment zone and the first treatment zone share a boundary.

6. The method of claim 4, wherein the forming a molten area of each treatment zone further comprises exposing the surface of each treatment zone to a second laser pulse.

7. A method of treating a substrate, comprising:

identifying a treatment zone of the substrate;

delivering a first plurality of laser pulses to the treatment zone, wherein each pulse of the first plurality of laser pulses melts a portion of the treatment zone, and a duration between each pulse of the first plurality of laser pulses is less than a time to freeze the portion of the treatment zone that melted; and

delivering a second plurality of laser pulses to the treatment zone of the substrate, wherein each pulse of the second plurality of laser pulses melts a portion of the treatment zone, and a duration between each pulse of the second plurality of laser pulses is more than a time to freeze the portion of the treatment zone that melted.

8. The method of claim 7, wherein each pulse of the first plurality of laser pulses overlaps with adjacent pulses.

9. The method of claim 7, wherein a duration between each pulse of the first plurality of laser pulses and adjacent pulses of the first plurality of laser pulses is the same, and wherein a duration between each pulse of the second plurality of laser pulses and adjacent pulses of the second plurality of laser pulses is the same.

10. The method of claim 7, wherein an intensity of each pulse of the first plurality of laser pulses and of each pulse of the second plurality of laser pulses is the same.