| 摘要 |
PURPOSE:To make it possible to obtain stable gate voltage and high mobility by using a low resistance substrate as a foundation substrate and forming an active layer reflecting orientation of the foundation. CONSTITUTION:An insulating layer 3 is provided on an n-type or p-type low resistance substrate 1' by a thermal oxidation method and a reduced pressure CVD method, and a desired spot is etched to form a window. Then, a p-type or n-type semiconductor layer 8 showing a reverse conduction type to the substrate 1' at least on one side of a part having the insulating layer 3 or a part having no insulating layer 3 is formed by a reduced or atmospheric pressure CVD method and a sputtering method. In this way, a basic thin film transistor of an n-channel or p-channel is formed. The function of such semiconductor layer holds the foundation substrate at positive or negative potential toward the semiconductor layer, which is an active layer, to cause voltage drop of a depletion layer portion at the junction part. Thereby, gate potential toward substrate potential can be controlled accurately. |
