Systems and methods for processing thin films

• US 7,364,952 B2
• Filed: 01/09/2004
• Issued: 04/29/2008
• Est. Priority Date: 09/16/2003
• Status: Expired due to Fees

• Current Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Im, James
• Primary Examiner(s): Wilczewski; Mary
• Assistant Examiner(s): Tran; Thanh Y.
• Application Number:
  US10/754,133
• Publication Number:
  US 20050059265A1
• Time in Patent Office: 1,572 Days
• Field of Search: 438/149, 438/150, 438/795, 438/799, 117/7, 117/10, 219/121.6, 219/121.76
• US Class Current: 438/150
• CPC Class Codes: B23K 26/0604 by a combination of beams
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/067 Dividing the beam into multiple beams, e.g. multifocusing
• CPC Class Codes: B23K 26/0673 into independently operating sub-beams, e.g. beam multiplexing to provide laser beams for several stations
• CPC Class Codes: H01L 21/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02678 Beam shaping, e.g. using a mask
• CPC Class Codes: H01L 21/02683 Continuous wave laser beam
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/02691 Scanning of a 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

Abstract

The present disclosure is directed to methods and systems for processing a thin film samples. In an exemplary method, semiconductor thin films are loaded onto two different loading fixtures, laser beam pulses generated by a laser source system are split into first laser beam pulses and second laser beam pulses, the thin film loaded on one loading fixture is irradiated with the first laser beam pulses to induce crystallization while the thin film loaded on the other loading fixture is irradiated with the second laser beam pulses. In a preferred embodiment, at least a portion of the thin film that is loaded on the first loading fixture is irradiated while at least a portion of the thin film that is loaded on the second loading fixture is also being irradiated. In an exemplary embodiment, the laser source system includes first and second laser sources and an integrator that combines the laser beam pulses generated by the first and second laser sources to form combined laser beam pulses. In certain exemplary embodiments, the methods and system further utilize additional loading fixtures for processing additional thin film samples. In such methods and systems, the irradiation of thin film samples loaded on some of the loading fixtures can be performed while thin film samples are being loaded onto the remaining loading fixtures. In certain exemplary methods and systems, the crystallization processing of the semiconductor thin film samples can consist of a sequential lateral solidification (SLS) process.

Claims

1. A method of processing a plurality of thin films, comprising:

loading a first thin film onto a first loading fixture;

loading a second thin film onto a second loading fixture;

generating laser beam pulses, each said generated laser beam pulse having a pulse duration;

splitting each said generated laser beam pulse into at least a first laser beam pulse and a second laser beam pulse;

directing at least one first laser beam pulse onto a first optical path and directing at least one second laser beam pulse onto a second optical path;

irradiating said first thin film with said at least one first laser beam pulse to induce melting and subsequent crystallization of at least a portion of said first thin film; and

irradiating said second thin film with said at least one second laser beam pulse to induce melting and subsequent crystallization of at least a portion of said second thin film, wherein at least a portion of said step of irradiating said first thin film and at least a portion of said step of irradiating said second thin film occur simultaneously.

2. The method of claim 1, further comprising:

loading a third thin film onto a third loading fixture while said first thin film is being irradiated;

directing at least one first laser beam pulse onto a third optical path upon completing the processing of said first thin film;

irradiating said third thin film with said at least one first laser beam directed via said third optical path to induce melting and subsequent crystallization of at least a portion of said third thin film;

unloading said first thin film from said first loading fixture; and

loading another thin film onto said first loading fixture, wherein said steps of unloading said first thin film from said first loading fixture and loading another thin film onto said first loading fixture substantially occur while said third thin film is being irradiated.

3. The method of claim 2, further comprising:

loading a fourth thin film onto a fourth loading fixture while said second thin film is being irradiated;

directing at least one second laser beam pulse onto a fourth optical path upon completing the processing of said second thin film

irradiating said fourth thin film with said at least one second laser beam directed via said fourth optical path to induce melting and subsequent crystallization of at least a portion of said fourth thin film;

unloading said second thin film from said second loading fixture; and

loading another thin film onto said second loading fixture, wherein said steps of unloading said second thin film from said second loading fixture and loading another thin film onto said second loading fixture substantially occur while said fourth thin film is being irradiated.

4. The method of claim 1, wherein said irradiating said first thin film comprises at least one of the following:

an excimer laser anneal (ELA) process, a sequential lateral solidification (SLS) process and a uniform grain structure (UGS) crystallization process.

5. The method of claim 1, wherein said first and second thin films are comprised of a semiconductor material.

6. The method of claim 5, wherein said semiconductor material comprises silicon, germanium or silicon-germanium.

7. The method of claim 1, wherein said first and second thin films are comprised of a metallic material.

8. The method of claim 1, wherein generating each said laser beam pulse having said pulse duration comprises:

generating a first component laser beam pulse having a first pulse duration;

generating a second component laser beam pulse having a second pulse duration; and

integrating said first component laser beam pulse with said second component laser beam pulse to form said laser beam pulse having said pulse duration.

9. The method of claim 8, wherein said first component laser beam pulse is integrated with said second component laser beam pulse with a time delay that exists between said first and second component laser beam pulses.

10. The method of claim 8, wherein at least a portion of said first component laser beam is constructively added to at least a portion of said second component laser beam pulse.

11. A method of processing a thin film, comprising:

loading a thin film onto a loading fixture;

generating laser beam pulses by generating initial laser beam pulses having an initial pulse duration, and modifying said initial laser beam pulses to generate laser beam pulses having a pulse duration longer than said initial pulse duration;

splitting said generated laser beam pulses into at least first laser beam pulses and second laser beam pulses;

irradiating a first region of said thin film with said first laser beam pulses to induce melting and subsequent crystallization of said first region of said thin film; and

irradiating a second region of said thin film with said second laser beam pulses to induce melting and subsequent crystallization of said second region of said thin film, wherein at least portions of said steps of irradiating said first region and irradiating said second region occur simultaneously.

12. The method of claim 11, wherein modifying said initial laser beam pulses comprises extending said initial laser beam pulses.

13. The method of claim 11, wherein generating initial laser beam pulses comprises generating first and second component laser beam pulses having first and second pulse durations, and wherein modifying said initial laser beam pulses comprises combining said first and second component laser beam pulses.

14. A method of processing a thin film, comprising:

loading at least one thin film onto at least one loading fixture;

generating laser beam pulses by generating initial laser beam pulses having an initial pulse duration, and modifying said initial laser beam pulses to generate laser beam pulses having a pulse duration longer than said initial pulse duration;

splitting said generated laser beam pulses into at least first laser beam pulses and second laser beam pulses;

irradiating a first region of said at least one thin film with said first laser beam pulses to induce melting and subsequent crystallization of said first region of said at least one thin film; and

irradiating a second region of said at least one thin film with said second laser beam pulses to induce melting and subsequent crystallization of said second region of said at least one thin film, wherein at least portions of said steps of irradiating said first region and irradiating said second region occur simultaneously.

15. The method of claim 14, wherein first and second regions are located on a single thin film.

16. The method of claim 14, wherein said first region is located on a first thin film and said second region is located on a second thin film.

17. The method of claim 14, wherein modifying said initial laser beam pulses comprises extending said initial laser beam pulses.

18. The method of claim 14, wherein generating initial laser beam pulses comprises generating first and second component laser beam pulses having first and second pulse durations, and wherein modifying said initial laser beam pulses comprises combining said first and second component laser beam pulses.