| US 7,537,979 B2 | ||
| Method of manufacturing semiconductor device | ||
| Atsuo Isobe, Kanagawa-ken (Japan); Satoru Saito, Kanagawa-ken (Japan); and Saishi Fujikawa, Kanagawa-ken (Japan) | ||
| Assigned to Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken (Japan) | ||
| Filed on Aug. 24, 2006, as Appl. No. 11/467,000. | ||
| Application 11/467000 is a continuation of application No. 10/919513, filed on Aug. 17, 2004, granted, now 7,115,488. | ||
| Claims priority of application No. 2003-307489 (JP), filed on Aug. 29, 2003. | ||
| Prior Publication US 2006/0281318 A1, Dec. 14, 2006 | ||
| Int. Cl. H01L 21/84 (2006.01) | ||
| U.S. Cl. 438—151 [438/978; 257/E21.259] | 30 Claims |
| 1. A method for manufacturing a semiconductor device comprising the steps of:
forming a conductive film over a glass substrate;
applying a photoresist to the conductive film by spin coating;
performing a first heat treatment to the photoresist;
performing an exposure to transfer a mask to the photoresist after performing the first heat treatment;
developing the photoresist by dropping or spraying a developer to the photoresist after performing the exposure;
performing a second heat treatment to the photoresist after developing to form a resist mask having tapered shape on an end
surfaces; and
etching the conductive film by using the resist mask by dry etching to form a conductive film with a gate electrode of a thin
film transistor, the gate electrode having a gate length of 1 μm or less.
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