| 摘要 |
PURPOSE:To manufacture a thin film transistor with high on-off ratio in fixed threshold value by a method wherein an impurity mixing process and a hydrogen mixing process are provided in a channel region of a thin film semiconductor layer. CONSTITUTION:A polysilicon thin film 11 is formed on an insulating substrate 12 such as quartz glass. At this time, specified impurity is thermal.diffused in the optimum concentration. First, the thin film 11 is thermal oxidized to form a gate layer 13, a gate electrode 14 forming the source and drain by ion implantation using the electrode 14 as a mask. Second, overall surface is covered with a CVD insulating film and after implanting H ions and annealing at 200-500 deg.C, a connecting hole and an interconnection 16 are made to be covered with a protective film 17 for completion. In such a constitution, even if the channel is mixed with sufficient H, the threshold value is fixed to assure the high on-off ratio. |
