Monolithic integrated circuit including Darlington amplifier - has transistor protected by Zener diode from overloading introduced without complicating mfr.

摘要

The monolithic integrated circuit consists of a transistor whose collector/base junction is protected against overloading by a Zener diode integrated into the circuit without making manufacture more complicated. The transistor collector consists of a lightly doped epitaxial layer on a heavily doped substrate. The base is formed by a heavily doped region of the same conduction type as the lightly doped region and extending over the bottom and sides of a 'trench' set into the surface of the device. The distance between this region and the substrate determines the max. base/collector breakdown voltage which is less than the collector/emitter breakdown voltage in the absence of the 'trench' and the region.