| 摘要 |
PURPOSE:To minimize leakage current of a thin film transistor by a method wherein a conductive layer of a gate electrode is arranged with a HTO film to form another conductive layer of polysilicon for the source/drain electrodes for making use of the HTO film as a gate insulating film. CONSTITUTION:Polysilicon layers 27a, 27b for intersecting connection parts serving both as gate electrodes of a thin film transistor are formed. Next, an HTO film 28 of a gate oxide film is deposited on the whole surface. This HTO film 28 is a gate insulating film covering the gate electrodes of the thin film transistor. An aperture part 28a etc., is formed in the HTO film 28. After covering the whole surface with a polysilicon layer 29, boron ions are selectively implanted to form a source diffused layer 29s and a drain diffused layer 29d. An oxide film is deposited by CVD process on the HTO film 28 wherein the vapor depositing temperature is set up at about 800 deg.C. In such a constitution, the leakage current in a thin film transistor can be minimized by using the HTO film 28 having excellent film quality by high temperature process. |
