A Power Bipolar Transistor Resistant to Secondary Breakdown

Abstract

The invention discloses a power bipolar transistor with resistance to secondary breakdown. Electrode P-region; base n region is set on collector P-region, collector-base p-n junction region is formed between collector P-region and base n region; set in base n region Emitter region, an emitter-base p-n junction region is formed between the base n region and the emitter region; a dielectric film is arranged on the base n region, and base ohmic contact regions are arranged on the dielectric film at intervals and the emitter ohmic contact region; the base n region also includes a base-collector p-n junction region and an additional doped collector region from left to right. Increase the resistance of the power bipolar transistor to secondary breakdown, adopt the design of adjustable over-voltage protection threshold, reduce the output capacity of the device, simplify the structure of the power bipolar transistor, and reduce the size of the power bipolar transistor.

Description

technical field [0001] The invention relates to the technical field of transistors, in particular to a power bipolar transistor with resistance to secondary breakdown. Background technique [0002] It is well known that the operation of transistors in circuits with inductive loads in the collector circuit is associated with large overvoltages that occur when the transistor is turned off, which can lead to reverse secondary breakdown and transistor failure. There are generally several ways to protect transistors from overvoltage. [0003] PRIOR ART 1. Known integrated transistor with overvoltage protection in which an additional protection transistor is used for overvoltage protection, including collector and emitter regions of a first conductivity class, opposite to the first conductivity class The base region of the second conductivity class and a highly doped region are located in the base region adjacent to the bottom of the emitter, have the same conductivity type as th...

AI Technical Summary

Problems solved by technology

However, the structure of at least two transistors used in this known device and their electrical connection using a metal bus has the following disadvantages: 1. The protection transistor occupies a certain area, which increases the total area of ​​the device

As the power of the main transistor increases, it is also necessary to increase the area of ​​the protection transistor, i.e. for the power transistor, the size of the device increases significantly

2. The capacitance of the protection transistor and the metal-dielectric-semiconductor capacitor formed by the collector and the metallization layer connecting the electrodes of the main transistor and the protection transistor are connected in parallel with the base-collector junction of the main transistor, resulting in a device capacitance increase

This design with the guard ring system has the following disadvantages: 1. The guard ring occupies a large area outside the active lattice, which greatly increases the area of ​​the transistor

However, the second base region must be wide enough to form the second emitter therein and provide contact to the emitter, that is, it must occupy a large area and be compatible with connecting the second emitter to the first base. pole metal busses, increasing the capacitance of the transistor

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