[Back to the Laser Materials Processing Patent Collection]
| United States Patent |
6,437,284
|
|
Okamoto
, et al.
|
August 20, 2002
|
Optical system and apparatus for laser heat treatment and method for
producing semiconductor devices by using the same
Abstract
An optical system that controls laser beam spot profile for forming a high
performance thin film by a laser heat treatment process is provided. In
the optical system that irradiates a rectangular laser beam on a film
formed on a substrate, intensity distribution forming, apparatus makes the
intensity distribution uniform in the longitudinal direction while
maintaining the properties of the laser beam 2 such as directivity in the
direction of shorter side, making it possible to concentrate the light to
a limit permitted by the nature of the laser beam and achieve the maximum
intensity gradient on the film disposed on the substrate. Thus a steep
temperature distribution can be generated on the film disposed on the
substrate and, as a result, high performance thin film can be formed.
| Inventors:
|
Okamoto; Tatsuki (Tokyo, JP);
Ogawa; Tetsuya (Tokyo, JP);
Furuta; Keisuke (Tokyo, JP);
Tokioka; Hidetada (Tokyo, JP);
Sasagawa; Tomohiro (Tokyo, JP);
Nishimae; Junichi (Tokyo, JP);
Inoue; Mitsuo (Tokyo, JP);
Sato; Yukio (Tokyo, JP)
|
| Assignee:
|
Mitsubishi Denki Kabushiki Kaisha (Tokyo, JP)
|
| Appl. No.:
|
599645 |
| Filed:
|
June 23, 2000 |
Foreign Application Priority Data
| Jun 25, 1999[JP] | 11-179233 |
| Current U.S. Class: |
219/121.73; 219/121.65; 438/487 |
| Intern'l Class: |
B23K 026/06 |
| Field of Search: |
219/121.73,121.75,121.65,121.66,121.74
438/487
|
References Cited
U.S. Patent Documents
| 4315130 | Feb., 1982 | Inagaki et al.
| |
| 4744615 | May., 1988 | Fan et al.
| |
| 4793694 | Dec., 1988 | Liu | 219/121.
|
| 5529951 | Jun., 1996 | Noguchi et al. | 219/121.
|
| 5897799 | Apr., 1999 | Yamazaki et al. | 219/121.
|
| 6249385 | Jun., 2001 | Yamazaki et al.
| |
| Foreign Patent Documents |
| 61-61657 | Dec., 1986 | JP.
| |
| 63-314862 | Dec., 1988 | JP.
| |
| 4-33791 | Feb., 1992 | JP.
| |
| 10-333077 | Dec., 1998 | JP.
| |
| 11-16851 | Jan., 1999 | JP.
| |
Other References
J. Carvalho et al.; "Nd-YAG Laser Induced Crystallization on a-Si:H Thin
Films", Mat. Soc. Symp. Proc., vol. 358, pp. 915-920 (1995).
B. Rezek et al.; "Polycrystalline Silicon Thin Films Produced by
Interference Laser Crystallization of Amorphous Silicon", Jpn. J. Appl.
Phys., vol. 38, pp. L1083-L1084 (1999).
|
Primary Examiner: Evans; Geoffrey S.
Attorney, Agent or Firm: Leydig, Voit & Mayer, Ltd.
[Back to the Laser Materials Processing Patent Collection]