MOS TRANSISTOR

PURPOSE:To enable controlling the current between a source and a drain in the comparatively later process of MOS transistor manufacturing processes by controlling the current between the source and the drain by forming an impurity-implanted region which interrupts the formation of an inversion layer in part of a channel region. CONSTITUTION:A field dope layer 6 and a field oxide layer 4 are formed on a p substrate 20 and a gate oxide film 8 is formed. Then, a gate electrode 10 is formed and a source and a drain are formed on the substrate 20. Then, boron-implanted regions 22a-22c are formed in a channel region. In the regions 22a-22c where boron is implanted, even if the voltage applied to the gate electrode 10 is raised, an inversion layer is not formed in the channel region and a transistor is not operated in a region (a). The normal transistor can be operated in a region (b) where the boron is not implanted. Accordingly, the current made to flow between the source 2S and the drain 2D is controlled by regulating the width of the region (b) since only the region (b) within the channel region can be considered as the transistor.