Device preventive of electrostatic breakdown in semiconductor integrated circuit device

Abstract

Abstract PURPOSE:To prevent an input transistor from being broken due to overcurrent, by forming a current-limiting resistor, a first diode serving as a protective element against negative surges, and a second diode serving as a protective element with respect to a longitudinal PNP transistor and positive surges on a semiconductor substrate. CONSTITUTION:A current-limiting resistor 5, and a first diode 2, whose anode is part of a semiconductor substrate and which is preventive of electrostatic breakage against negative surges, are disposed on a semiconductor substrate whereon a semiconductor integrated circuit device is composed. A PNP transistor 4 preventive of electrostatic breakage (bipolar transistor preventive of electrostatic breakage) to negative surge is formed in so longitudinal structure that part of the semiconductor substrate is an emitter, part of a cathode of the first diode 2 preventive of electrostatic breakage being a base, part of the current-limiting resistor 5 being a collector. A second diode 3 preventive of electrostatic breakage to positive surge is further formed. Hence, even if junction in the semiconductor integrated circuit device is small in depth, its input transistor is prevented from being broken.

Inventors

• 👤 Shuichi Kato
• 👤 周一 加藤

Bibliographic Details