IGBT device structure

Abstract

The invention discloses an IGBT device structure in the technical field of power semiconductor devices, aims to solve the technical problems that in the prior art, when an IGBT device adopting a virtual trench gate structure is turned off, the on-state voltage drop of a device cannot be reduced due to the fact that the concentration of carriers accumulated below a trench region is too low, and thedifficulty of opening a contact window from the middle of virtual trench polycrystalline silicon is increased as the width of a virtual trench is designed to be narrower and narrower. The top surfaceof the device is downwards provided with a plurality of active trenches and virtual trench regions which are distributed at intervals. Each virtual trench region comprises at least one bridge and a plurality of virtual trenches connected through the bridge, and a dielectric layer is provided with a contact window; and P-type well regions comprise a first P-type well region connected with the metal emitter through the contact window and a second P-type well region in a potential floating state.

Description

technical field [0001] The invention relates to an IGBT device structure, belonging to the technical field of power semiconductor devices. Background technique [0002] As a new type of power semiconductor device, IGBT has the advantages of high withstand voltage characteristics and low on-resistance, and also has the characteristics of simple gate control, high input impedance, fast switching speed, high current density, and saturation voltage drop. A new generation of mainstream products. [0003] At present, many IGBT devices adopt a dummy trench gate structure. The IGBT device adopting the virtual trench gate structure includes a virtual trench, and a strip-shaped contact window parallel to the strip-shaped trench gate is provided on the polysilicon of the virtual trench. It has the following defects: when the device is turned off, the carrier concentration accumulated under the trench region is too low, resulting in the on-state voltage drop of the device cannot be re...

AI Technical Summary

Problems solved by technology

It has the following defects: when the device is turned off, the carrier concentration accumulated under the trench region is too low, resulting in the on-state voltage drop of the device cannot be reduced; with the development of the process, the width of the dummy trench is also designed to be wider and wider. Narrower and narrower, its width can be less than 1.5 μm, the polysilicon width in the virtual trench is narrower, when the contact window connecting the metal emitter and the structure below the contact window is opened from the middle of the virtual trench polysilicon, the position accuracy error of the contact window very strict

The long-term high-temperature process will inevitably cause the wafer to warp under the action of thermal stress, making it difficult to reduce the alignment error of lithography, which is a very difficult problem to solve

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