Patent Number: 6,512,271

Title: Semiconductor device

Abstract: A semiconductor device that uses a high reliability TFT structure is provided. The gate electrode of an n-channel type TFT is formed by a first gate electrode and a second gate electrode that covers the first gate electrode. LDD regions have portions that overlap the second gate electrode through a gate insulating film, and portions that do not overlap. As a result, the TFT can be prevented from degradation in an ON state, and it is possible to reduce the leak current in an OFF state.

Inventors: Yamazaki; Shunpei (Tokyo, JP), Ohtani; Hisashi (Kanagawa, JP), Nakajima; Setsuo (Kanagawa, JP)

Assignee: Semiconductor Energy Laboratory Co., Ltd.

International Classification: H01L 21/70 (20060101); H01L 27/12 (20060101); H01L 29/66 (20060101); H01L 21/336 (20060101); H01L 29/786 (20060101); H01L 21/02 (20060101); H01L 21/84 (20060101); H01L 027/01 (); H01L 029/04 ()

Expiration Date: 01/28/2020