RET IGBT device structure with separation gate structure and manufacturing method thereof

A device structure and separation gate technology, applied in semiconductor/solid-state device manufacturing, semiconductor devices, electrical components, etc., can solve the problems of reducing blocking ability, reducing device switching speed, increasing switching loss, etc., and reducing leakage current. , the effect of reducing charging and reducing switching loss

Pending Publication Date: 2021-12-24
UNIV OF ELECTRONICS SCI & TECH OF CHINA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the PN junction between the introduced storage layer and the P base region will establish a strong electric field, causing the device to reach the avalanche breakdown condition in advance under a lower pressure, and the blocking capability is reduced.
In order to avoid premature breakdown of the device, the trench gate needs to be deepened. However, the depth of the deep trench gate will increase the gate capacitance, which will reduce the switching speed of the device and increase the switching loss.

Method used

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  • RET IGBT device structure with separation gate structure and manufacturing method thereof
  • RET IGBT device structure with separation gate structure and manufacturing method thereof
  • RET IGBT device structure with separation gate structure and manufacturing method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0086] An embodiment of a RET IGBT device with a split gate structure, such as figure 2 As shown, it includes: collector metal 1, P-type collector region 2, N-type field stop layer 3 and N-drift region 4 stacked in sequence from bottom to top, and the trench gate located above N-drift region 4 structure and a trench emitter structure, the trench gate structure includes a separation gate dielectric layer 6, a separation gate electrode 17 above the separation gate dielectric layer 6, a gate dielectric layer 18 above the separation gate electrode 17, and a gate dielectric layer 18 in the gate dielectric layer 18 The polysilicon gate electrode 7 and the isolation dielectric layer 10 above the polysilicon gate electrode 7, the trench emitter structure includes a trench emitter dielectric layer 14 and a polysilicon trench emitter electrode 15 in the trench emitter dielectric layer 14;

[0087] There is an N-type buried layer 16 between the trench gate structure and the trench emitte...

Embodiment 2

[0125] An embodiment of a RET IGBT device with a split gate structure, such as image 3 As shown, the difference between this embodiment and Embodiment 1 is that the polycrystalline trench emitter electrode 15 includes a P-type doped polysilicon electrode 151 and an N-type doped polysilicon electrode 152 below the P-type doped polysilicon electrode 151, so The doping concentration of the N-type doped polysilicon electrode 152 is less than the concentration of the P-type doped polysilicon electrode 151, the thickness of the N-type doped polysilicon electrode 152 is less than the thickness of the P-type doped polysilicon electrode 151, and the N-type Doped polysilicon is fully depleted.

[0126] By doing different doping to the polysilicon electrode of the trench emitter structure, when the device is turned off, the PN junction formed by the trench emitter is reverse-biased, and the N-type doped polysilicon electrode 152 has a lower doping concentration and a smaller thickness. ...

Embodiment 3

[0128] An embodiment of a RET IGBT device with a split gate structure, such as Figure 4As shown, the difference between this embodiment and Embodiment 1 is that the polysilicon gate electrode 7 includes a P-type doped polysilicon electrode 71, an N-type doped polysilicon electrode 72 below the P-type doped polysilicon electrode 71, and an N-type doped polysilicon electrode 72. The concentration of 72 is less than that of the P-type doped polysilicon electrode 71 , and the thickness of the N-type doped polysilicon electrode 72 is less than the thickness of the P-type doped polysilicon electrode 71 .

[0129] When the device is turned off, the PN junction in the trench gate is reverse-biased, and the N-type region is completely depleted, reducing the gate capacitance Cge.

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PUM

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Abstract

The present invention provides an RET IGBT device structure with a separation gate structure and a manufacturing method of the RET IGBT device structure. A P-type buried layer is introduced below an N-type charge storage layer, and an N-type buried layer is introduced at the left side of the P-type buried layer, so that the influence of the high-concentration P-type buried layer on the threshold voltage of a device is eliminated; an electron current can flow into an N-type drift region through the N-type buried layer, and the on-state characteristic of the device is not influenced. According to the present invention, a gate electrode is divided into the upper part and the lower part, the upper part serves as the grid electrode, the lower part is connected with an emitting electrode, so that the miller capacitance Cgc is reduced through the separation gate structure, and then the switching loss is reduced. Meanwhile, the thickness of an oxide layer at the bottom of a separation gate can be further improved, or the dielectric materials with high dielectric constants can be used to improve the electric field concentration at the bottom of a groove and improve the reliability of the device. When the device is turned off, the opening of a PMOS provides an additional extraction path for a hole, and the turn-off of the current is accelerated.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and relates to a RET IGBT device structure with a split gate structure and a manufacturing method thereof. Background technique [0002] Insulated Gate Bipolar Transistor (IGBT) is a power device developed on the basis of Metal Oxide Field Effect Transistor (MOSFET) and Bipolar Junction Transistor (BJT). IGBT not only has the advantages of strong MOSFET gate control ability, high input impedance, and low driving power, but also has the advantages of BJT with small turn-on voltage drop, high current carrying density, and strong withstand voltage capability. At present, IGBT has been widely used in various medium and high voltage fields such as consumer electronics, automotive electronics, new energy industry, and smart grid, and has become a research hotspot and main development direction of power devices. [0003] The initial product of the IGBT is the punch-through IGBT (PT-...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L29/06H01L29/423H01L29/739H01L21/28H01L21/331
CPCH01L29/7398H01L29/7397H01L29/66348H01L29/0684H01L29/0696H01L29/401H01L29/42312
Inventor 张金平肖翔尹俊博张波
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
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