THIN FILM TRANSISTOR

摘要

PURPOSE:To prevent the characteristics of a transistor from deteriorating due to the response property of an OFF current value to light in a thin film transistor formed using a polycrystalline Si layer as an active layer on a transparent insulating substrate by a method wherein a light-shielding layer is provided on the surface on the side opposite to the surface, whereon the transistor is constituted, of the substrate. CONSTITUTION:An active polycrystalline Si layer 2, a gate insulating film 3 and a gate electrode 4 are laminated in order on the surface of a transparent insulating substrate 1, an interlayer insulating film 5 is provided on these and moreover, a metal wiring 6 is provided to constitute a thin film transistor. A light-shielding layer 7 is provided on the side opposite to the side of the surface of the substrate 1, whereon such a transistor is provided, that is, on the rear of the substrate 1. By forming this layer 7 using poly Si, the layer 7 functions as a light-shielding layer to light from the rear and shows the same photo absorption as that of the active layer. Thereby, the trouble die to the response property of an OFF current value to light is prevented and the OFF current value is kept at a low value and is stabilized.