Abstract: An MOS transistor having a closed layout plan in which the drain is laterally surrounded by the source and gate and having an extended charge carrier drift zone between the gate and drain, thereby achieving high reverse breakdown voltage. An oxide or other dielectric layer is provided on the surface of the drift zone, and on such layer between the gate and drain electrodes a crossover path is formed by a succession of unconnected narrow conductive strips extending transversely to such path and having a dielectric coating thereon. A high voltage external connection bus for the drain electrode traverses such crossover path and extends through a gap formed by a disjuncture in the gate and source electrodes. Since the length of each of the conductive strips greatly exceeds the width of the connection bus, the coupling capacitance between each strip and such bus in much less than the coupling capacitance between such strip and the underlying portion of the drift zone.