| 摘要 |
PURPOSE:To improve a breakdown voltage and to facilitate a manufacturing process by the constitution in which the polycrystalline Si layer which is formed unitarily with the polycrystalline Si layer as a gate electrode is combined with a drain region. CONSTITUTION:The polycrystalline Si layer on a channel part, i.e. the real gate among gate electrodes is formed by a source-side part 9 of a polycrystalline Si layer 4 and is connected to a drain-peripheral part 10 through high resistance of an intrinsic central part 8 so that it is nearly isolated electrically. In this case, if the predetermined drain voltage is applied to a drain region 6 through a contact 16, as the drain-peripheral part 11 of the polycrystalline-Si layer 4 is combined through the capacitance in which a gate insulating film 3 is a dielectric, the potential of the drain-peripheral part 11 increases and produces a depletion layer under the drain-peripheral part 11. Consequently, the depletion layer from the drain region 6 easily extends under the drain-peripheral part 11. Then a junction breakdown voltage is increased and the breakdown voltage of the whole MOSFET can be increased. |
