A trench gate charge storage type igbt and its manufacturing method

A charge storage and charge storage layer technology, which is applied in the manufacturing of circuits, electrical components, semiconductor/solid-state devices, etc., can solve problems such as the compromise characteristics affecting the switching loss of the device, increasing the switching loss of the device, and reducing the switching speed.

Active Publication Date: 2020-05-01
UNIV OF ELECTRONICS SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The implementation of method (1) will increase the gate-emitter capacitance and gate-collector capacitance at the same time, and the switching process of the IGBT is essentially the process of charging / discharging the gate capacitance, so the increase in the gate capacitance will Makes the charging / discharging time longer, which in turn causes the switching speed to decrease
Therefore, the deep trench gate depth will reduce the switching speed of the device, increase the switching loss of the device, and affect the compromise characteristics of the device's conduction voltage drop and switching loss; and the implementation of method (2) will increase the device's switching loss The gate capacitance will reduce the switching speed of the device and increase the switching loss, which will affect the compromise between the conduction voltage drop and switching loss of the device. On the other hand, the large channel density will also increase the saturation current density of the device, making the device short-circuit safe. Work Area (SCSOA) Deterioration
In addition, the gate oxide layer in the trench gate structure is formed in the trench by one thermal oxidation. In order to ensure a certain threshold voltage, the thickness of the entire gate oxide layer is required to be small. However, the MOS capacitance and the thickness of the oxide layer Inversely proportional to this, this makes the gate capacitance in the traditional CSTBT device significantly increased, and the electric field concentration effect at the bottom of the trench will reduce the breakdown voltage of the device, resulting in poor reliability of the device

Method used

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  • A trench gate charge storage type igbt and its manufacturing method
  • A trench gate charge storage type igbt and its manufacturing method
  • A trench gate charge storage type igbt and its manufacturing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0099] A trench gate charge storage type IGBT, one-half of the cell such as Figure 4 As shown, its section along AB line and CD line is as follows Image 6 with Figure 7 As shown, a three-dimensional coordinate system is established with any inflection point of one-half cell as the origin, and the bottom surface of one-quarter cell intersects with the two sides of the inflection point as the x-axis and z-axis respectively, passing through the inflection point and A straight line perpendicular to the bottom surface is used as the y-axis, and the directions of the x, y, and z-axes refer to Figure 4 ;

[0100] The half cell includes a collector metal 14, a P-type collector region 13, an N-type drift region 9, and an emitter metal 1 stacked sequentially from bottom to top; the top layer of the N-type drift region 9 has N-type charge storage layer 6, P-type base region 5, P+ body contact region 4 and N+ emitter region 3; the P-type base region 5 is located on the top layer of...

Embodiment 2

[0103] A trench gate charge storage type IGBT, one-half of the cell such as Figure 8 As shown, its section along AB line, CD line, EF line and GH line is as follows Figures 10 to 13 As shown, the establishment method of the coordinate system is the same as that in Embodiment 1, see for details Figure 8 ;

[0104] The difference between this embodiment and Embodiment 1 is that the extension depth of the gate electrode 71 in the top layer of the N-type drift region 9 in this embodiment is equal to the extension depth of the split electrode 81, but the extension width of the gate electrode 71 at both ends of the top layer of the device is less than The extended width of the split electrode 81, while retaining part of the split electrode dielectric layer 82 and part of the split electrode 81 structure on the top layer of the device; the thickness of the split electrode dielectric layer 82 is greater than the thickness of the gate dielectric layer 72.

[0105] In this embodime...

Embodiment 3

[0107] A trench gate charge storage type IGBT, one-half of the cell such as Figure 14 As shown, its section along AB line, CD line, EF line and GH line is as follows Figures 16 to 19 As shown, the establishment method of the coordinate system is the same as that in Embodiment 1, see for details Figure 14 ;

[0108] The difference between this embodiment and Embodiment 2 is that: this embodiment does not have a split electrode 81 and a split electrode dielectric layer 82 structure on the top layer of the device, the split electrode 81 and the split electrode dielectric layer 82 are located at the bottom of the gate electrode 71, and the N+ emitter region 3 It is equal to the depth of the P+ body contact region 4 along the z-axis direction and less than the depth of the P-type base region 5 along the z-axis direction. The thickness of the gate electrode 71 connected to the region 3

[0109] In this embodiment, by changing the width of the gate electrode 71, under the same ...

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Abstract

A trench gate charge storage type IGBT and a manufacturing method thereof belong to the technical field of power semiconductor devices. By reducing the depth of the emitter region extending along the top layer of the base region in the traditional trench gate charge storage type IGBT structure, and introducing a split trench gate structure, the split trench gate structure includes the gate electrode and its surrounding gate dielectric layer and the The split electrode at the bottom of the gate electrode and connected by the gate dielectric layer and the split electrode dielectric layer around it, the split electrode and the emitter metal have the same potential. The device structure proposed by the present invention improves the short-circuit safe working area, temperature characteristics, forward conduction voltage drop Vceon and turn-off loss Eoff of the device while avoiding the limitation of the doping concentration and thickness of the charge storage layer on the device withstand voltage The compromise relationship among them avoids the current, voltage oscillation and EMI problems in the dynamic process of device opening, and improves the reliability of the device.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, in particular to a trench gate charge storage type insulated gate bipolar transistor (CSTBT). Background technique [0002] Insulated gate bipolar transistor (IGBT) is a new type of power electronic device developed based on the research of power MOSFET and power bipolar junction transistor (BJT), which is equivalent to a MOSFET driven by bipolar junction transistor (BJT). IGBT has the advantages of both power MOSFET structure and bipolar junction transistor (BJT) structure: it has the advantages of easy driving of power MOSFET, low input impedance and fast switching speed, and has the on-state current density of bipolar junction transistor (BJT) Large, low conduction voltage, low loss, and good stability. Based on these excellent device characteristics, IGBT has become a mainstream power device widely used in medium and high voltage fields in recent years, such as electric v...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L29/739H01L21/331H01L29/06H01L29/423
CPCH01L29/0603H01L29/0684H01L29/4236H01L29/66325H01L29/7393
Inventor 张金平赵倩赵阳刘竞秀李泽宏张波
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
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