| abstract |
(57) Abstract: In a liquid crystal display device using a thin film transistor using polycrystalline silicon for a driving circuit portion, a high performance thin film transistor which does not cause a problem in a driving circuit when displaying a large screen, and a high performance thin film transistor. A main object is to provide a liquid crystal display device used. SOLUTION: In a thin film transistor in which a polycrystalline silicon thin film formed on a transparent insulating substrate 11 is used as an active region, crystal grains of the polycrystalline silicon thin film are grown anisotropically in a specific direction in a plane and silicon is removed. The crystal grains are grown in an elongated shape, and the gate length direction of the thin film transistor is manufactured so as to be substantially parallel to the longitudinal direction of the crystal grains, so that the mobility of carriers in the active region (channel) of the TFT is improved. |