Method of manufacturing a semiconductor device

(54) METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE

(75) Inventor: Tamae Takano, Atsugi (JP)

(73) Assignee: Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken (JP)

( * ) Notice: Subject to any disclaimer, the term ol this patent is extended or adjusted under 35 U.S.C. 154(b) by 90 days.

(21) Appl. No.: 10/614,110

(22) Filed: Jul. 8, 2003

(65) Prior Publication Data

US 2004/0023444 Al Feb. 5, 2004 (30) Foreign Application Priority Data

Jul. 9, 2002 (JP) 2002-200555

(51) Int. CI.7 H01L 21/00

(52) U.S. CI 438/149; 438/486; 438/487;

438/488; 438/502; 438/509; 438/166; 438/482;

438/479; 438/471

(58) Field of Search 438/149, 486,

438/487, 488, 502, 509, 166, 482, 479,

471

(56) References Cited

U.S. PATENT DOCUMENTS

5,639,698 A * 6/1997 Yamazaki et al 438/486

6,218,219 Bl * 4/2001 Yamazaki et al 438/149

6,348,368 Bl * 2/2002 Yamazaki et al 438/166

6,365,933 Bl 4/2002 Yamazaki et al.

6,455,401 Bl * 9/2002 Zhang et al 438/486

6,692,996 B2 * 2/2004 Lee et al 438/149

6,703,265 B2 * 3/2004 Asami et al 438/150

6,808,965 Bl * 10/2004 Miyasaka et al 438/151

The present invention provides a manulacturing method ol a semiconductor device, which is able to improve on-current and mobility ol a polycrystal TFT without disturbing a high integration level, and also provide a semiconductor device obtained in accordance with the manulacturing method. The manulacturing method comprises steps ol adding a catalytic element to a semiconductor film and heating the semiconductor film to form a more crystallized first region; forming a less crystallized second region than the first region; irradiating first laser light to the first region to form a more crystallized third region than the first region; irradiating second laser light to the second region to form a more crystallized fourth region than the second region; and patterning the third region to form a first island-shaped region and the fourth region to form a second island-shaped region, wherein the first laser light has the same energy density from the second laser light, and a scan speed of the first laser light is faster than that of the second laser light.

30 Claims, 16 Drawing Sheets