| abstract |
(57) [Abstract] [Purpose] In a thin film transistor, the reliability between the gate electrode / wiring and the thin film semiconductor region (active layer) is improved to improve the characteristics. [Structure] An end portion of the island-shaped thin film semiconductor region is processed into a taper shape, and an impurity having a conductivity type opposite to that of a source or a drain, or oxygen, carbon, or nitrogen is mixed into the end portion region, Alternatively, by irradiating with high-speed ions, the end region is made to have a high resistance and the leak current between the source and the drain or between the gate and the drain is reduced. |