| 摘要 |
PURPOSE:To prevent the formation of a back channel by a method wherein the work function of the interface between the insulation layer in a semiconductor substrate is made equal to or larger than the work function of the interface between the insulation layer in a semiconductor region formed under the gate of an MOS element. CONSTITUTION:The semiconductor substrate 11', the work function of which is equal to or larger than the work function of the channel region 14 under a gate electrode 16, is provided and then grounded. The work function can be controlled e.g. according to the impurity concentration; when the impurity concentration of the channel region 14 is set, the impurity concentration of the substrate 11' is set equal to or larger than it. Thereby, holes generated in the insulation layer 12 by the irradiation of ionized radiation are led to the side of the substrate 11' by means of the electric field in the layer 12 generated by the difference in work functions between the substrate 11' and the channel region 14, and the trapping of holes at the interface between the layer 12 in the region 14 can be reduced without the application of negative bias on the substrate 11', resulting in the prevention of the formation of the back channel. |
