Groove type igbt and preparation method thereof

Abstract

The invention provides a trench type IGBT and a preparation method thereof. The trench type IGBT includes an epitaxial layer and an active region, the active region extends from the upper surface of the epitaxial layer into the epitaxial layer, and includes at least one cell, each The cell includes: a first trench, a second trench and a third trench; a first gate oxide layer, a second gate oxide layer and a third gate oxide layer; a first gate, a second gate and a third gate oxide Tri-gate; first sub-gate and second sub-gate; first shallow well region and second shallow well region; first contact region and second contact region; first emitter and second emitter; An insulating dielectric layer and a second insulating dielectric layer; a deep well region, wherein the depth of the deep well region is greater than that of the first shallow well region and the second shallow well region. While the trench type IGBT has smaller Miller capacitance and better switching characteristics, it also has better reverse withstand voltage capability, better EAS capability, and lower conduction loss.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a trench type IGBT and a preparation method thereof. Background technique [0002] Trench gate power devices have higher integration and lower conduction loss than planar gate power devices, and are widely used in insulated gate metal-oxide-semiconductor field effect transistors (MOSFETs). The split gate MOSFET is proposed to further reduce the conduction loss of the device, and also reduce the Miller capacitance of the device, improve the switching characteristics of the device, and has achieved great success in low-voltage MOSFET applications. After the success of the split gate MOSFET, the splitgate technology has been applied to the insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT), such as figure 1 shown. However, the current reverse blocking capability of the split gate IGBT is poor, which cannot meet the requirements of medium and high vo...

AI Technical Summary

Problems solved by technology

However, the current reverse blocking capability of split gate IGBT is poor, which cannot meet the requirements of medium and high voltage environments, and the single pulse avalanche breakdown capability (Avalanche energy, single pulse; EAS) of the device will be relatively poor, and the conduction loss is relatively high.

[0003] Therefore, the current split gate IGBT still needs to be improved

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