Grid control diode with high surge current resistance

Abstract

The invention relates to a grid-controlled diode with high surge current resistance, and belongs to the technical field of power semiconductor devices. According to the gate-controlled diode with the high surge current resistance, one-way current conduction is carried out by adopting a channel of an MOS (Metal Oxide Semiconductor). In order to reduce the forward conduction voltage drop of the diode, an accumulation channel is adopted to replace a conventional inversion channel. Besides, in order to improve the anti-surge capability of the device, PNP triodes which are connected in parallel are integrated for the grid-control diode, the addition of the triodes enables the base region of the triode to be conductively modulated when surge current arrives, the bulk resistance of the base region of the triode is reduced, and furthermore, the collector junction of the triode is reversely biased, so that the anti-surge capability of the device is improved. And the current entering the base region from the emitter region is further amplified.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and in particular relates to a gate-controlled diode with high anti-surge current capability. Background technique [0002] Traditional power diodes are mainly divided into two categories: Schottky diodes and PIN diodes. [0003] Schottky diodes have become mainstream low-voltage devices (≤150V) thanks to their low manufacturing cost and low forward voltage drop, but due to the physical properties of the Schottky barrier itself (such as the electric field-induced barrier lowering effect) ) makes a significant increase in the leakage current of the Schottky in the high voltage and high temperature environment. Now, this makes the Schottky diode unable to be used in higher voltage scenarios. [0004] The barrier of PIN diodes is more stable than Schottky diodes, which makes them the first choice for high-temperature and high-voltage applications, but PIN diodes are bipolar devi...

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Problems solved by technology

[0006] However, with the improvement of the withstand voltage of the device, the thickness of the drift region of the gate-controlled diode becomes thicker and thicker, which leads to the fact that when we continue to use the traditional parasitic PIN diode for anti-surge current, the power consumption caused by the same surge current will decrease. With the increase of the thickness of the drift region, there is an exponential growth trend

This is because the increase in the thickness of the drift region increases the diffusion length of the parasitic PIN diode minority carriers (holes) in the drift region, which will cause most of the minority carriers to be recombined in the drift region, so that they cannot contribute to the Inrush current

The electronic current formed by the recombination of minority carriers will be carried by the MOS channel, which reduces the reliability of the gate oxide layer of the gate-controlled diode.

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