Dual-gate carrier stored IGBT device with P-type buried layer

Abstract

The invention provides a dual-gate carrier stored IGBT device with a P-type buried layer. A control gate and a shield gate are added to a conventional CSTBT trench gate and a P-type buried layer is added to the bottoms of the two gates. When the device operates, the control gate is configured to switch on the device to a high potential, the shield gate is configured to reduce device capacitance and control the device not to be connected to a potential. The P-type buried layer is configured to reduce the electric field peaks of the left and right control gates and the left and right shield gates. By reasonably adjusting the concentration and junction depth of a P-bury region and the distance between the shield gates, the electric field peak at the bottom of the trench can be reduced, the breakdown voltage of the device can be increased, and the gate-collector capacitance and the gate-emitter capacitance of the device can be reduced, thereby achieving an effect of increasing the switching speed.

Description

technical field [0001] The invention belongs to the technical field of power devices, and relates to an insulated gate bipolar transistor (IGBT), in particular to a trench gate carrier storage type insulated gate bipolar transistor (CSTBT). Background technique [0002] Since the invention of the insulated gate bipolar transistor in the last century, it has been widely used in various fields due to its advantages of low conduction voltage, large on-state current, low loss and easy driving. Especially when it is applied in the field of industrial high voltage, it is required to have a low on-state conduction voltage drop while withstanding high withstand voltage. The traditional Trench IGBT (TIGBT) was invented due to the need for lower turn-on voltage drop and higher integration as the cell width decreases. However, the reliability of TIGBT is not as good as conventional IGBT, such as short-circuit operating safe area (SCSOA) and degradation of breakdown voltage. [0003] ...

AI Technical Summary

Problems solved by technology

However, the electric field concentration near the junction of the P-base / CS layer greatly affects the breakdown voltage of the device, especially when the concentration of the CS layer increases, the effect is more obvious

On the other hand, because of the introduction of the trench gate, it is easy to form an electric field spike at the bottom of the trench, thereby further reducing the withstand voltage of the device

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