MULTILAYER OVERVOLTAGE PROTECTION DEVICE

摘要

PURPOSE: To provide a solid state overvoltage protection device which substantially reduces an overshoot voltage and provides a more high sensitivity and accuracy. CONSTITUTION: The device comprises many short-circuit dots 37 in an emitter region 39 and many buried regions 42 substantially matched with these dots. The position, number and area of the buried regions are set so as to reduce the device overshoot voltage and more accurately set the voltage value with keeping a high surge ability of the device. The dopant type and concn. are changed from the known values to reduce the overshoot.