Patent ID: 7939908

Claim:
A semiconductor device comprising: a plurality of high-voltage insulated-gate field-effect transistors arranged in a matrix form on a main surface of a semiconductor substrate and having gate electrodes formed to extend in a gate-width direction, the transistors arranged in the gate-width direction commonly having a corresponding one of the gate electrodes; first shielding gates provided on portions of an element isolation region which lie between the transistors adjacent in the gate-width direction; and second shielding gates provided on portions of the element isolation region which lie between the transistors adjacent in the gate-length direction, wherein the first and second shielding gates are different from portions of the element isolation region on which the gate electrodes are formed and used to apply one of a reference potential and a potential of a polarity different from that of potential applied to the gate of the transistor to turn on a current path of the transistor to the element isolation region; and one of the first shielding gates and one of the second shielding gates cross each other at right angles.