(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2001/0000243 Al
Sugano et al. (43) Pub. Date: Apr. 12,2001
(54) PROCESS FOR PRODUCING THIN FILM SEMICONDUCTOR DEVICE AND LASER IRRADIATION APPARATUS
(76) Inventors: Yukiyasu Sugano, Kanagawa (JP);
Masahiro Fujino, Kanagawa (JP);
Michio Mano, Kanagawa (JP); Akihiko
Asano, Kanagawa (JP); Masumitsu
Ino, Kanagawa (JP); Takenobu
Urazono, Kanagawa (JP); Makoto
Takatoku, Kanagawa (JP)
Correspondence Address:
Ronald P. Kananen
Suite 501
1233 20th Street, N.W.
Washington, DC 20036 (US)
(21) Appl. No.: 09/731,905
(22) Filed: Dec. 8, 2000
Related U.S. Application Data
(62) Division of application No. 09/478,812, filed on Jan. 7, 2000.
(30) Foreign Application Priority Data
Jan. 8, 1999 (JP) Pll-002384
Jan. 8, 1999 (JP) Pll-002385
Jan. 20, 1999 (JP) Pll-012498
Publication Classification
(51) Int. CI.7 H01L 21/00; H01L 21/84;
H01L 21/336
(52) U.S. CI 438/166; 438/308
(57) ABSTRACT
A polycrystalline thin film of good quality is obtained by improving a crystallization process of a semiconductor thin film using laser light. After conducting a film forming step of forming a non-single crystal semiconductor thin film on a surface of a substrate, an annealing step is conducted by irradiating with laser light to convert the non-single crystal semiconductor thin film to a polycrystalline material. The annealing step is conducted by changing and adjusting the cross sectional shape of the laser light to a prescribed region. The semiconductor thin film is irradiated once or more with a pulse of laser light having an emission time width from upstand to downfall of 50 ns or more and having a constant cross sectional area, so as to convert the semiconductor thin film contained in an irradiated region corresponding to the cross sectional area to a polycrystalline material at a time. At this time, the energy intensity of laser light from upstand to downfall is controlled to apply a desired change. According to the procedures, a polycrystalline material having a large particle diameter or a uniform particle diameter can be obtained. In some cases, upon irradiation with laser light, the substrate may be maintained in a non-oxidative atmosphere, or may be heated or cooled.
