(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2003/0092213 Al
Yamazaki et al. (43) Pub. Date: May 15,2003
(54) SEMICONDUCTOR DEVICE AND METHOD FOR ITS FABRICATION
(75) Inventors: Shunpei Yamazaki, Atsugi-shi (JP);
Yasuyuki Arai, Atsugi-shi (JP)
21010 SOUTHBANK ST.
POTOMAC FALLS, VA 20165 (US)
(73) Assignee: Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi (JP)
(21) Appl. No.: 10/292,875
(22) Filed: Nov. 13, 2002
Related U.S. Application Data
(62) Division of application No. 09/570,612, filed on May 12, 2000, now Pat. No. 6,492,659.
(30) Foreign Application Priority Data
May 15, 1999 (JP) 11-171485
May 31, 1999 (JP) 11-152902
(51) Int. CI.7 H01L 21/00; H01L 21/84
(52) U.S. CI 438/48; 438/150; 438/149;
To fabricate a crystalline semiconductor film with controlled locations and sizes of the crystal grains, and to utilize the crystalline semiconductor film in the channel-forming region of a TFT in order to realize a high-speed operable TFT. A translucent insulating thermal conductive layer 2 is provided in close contact with the main surface of a substrate 1, and an insular or striped first insulating layer 3 is formed in selected regions on the thermal conductive layer. A second insulating layer 4 and semiconductor film 5 are laminated thereover. The semiconductor film 5 is first formed with an amorphous semiconductor film, and then crystallized by laser annealing. The first insulating layer 3 has the function of controlling the rate of heat flow to the thermal conductive layer 2, and the temperature distribution difference on the substrate 1 is utilized to form a single-crystal semiconductor film on the first insulating layer 3.