Unlock instant, AI-driven research and patent intelligence for your innovation.

Super junction MOS power semiconductor device and preparation method thereof

A technology of power semiconductors and semiconductors, applied in semiconductor/solid-state device manufacturing, semiconductor devices, electrical components, etc., can solve the problems that the drift region cannot be completely exhausted, reduce the on-resistance, etc.

Active Publication Date: 2019-01-01
UNIV OF ELECTRONICS SCI & TECH OF CHINA
View PDF4 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Aiming at the defects existing in the prior art, the present invention provides a superjunction MOS device and its preparation method, mainly through the introduction of a three-dimensional superjunction structure to overcome the problem that the drift region cannot be completely depleted due to thick drift regions and deep trenches, While improving the withstand voltage performance of the device, it can reduce its on-resistance, and there is no need to extend the gate structure to the buried oxide layer to provide electric field adjustment, thereby reducing the gate capacitance and improving the switching speed of the device; further introducing a buffer layer can improve the drift The effect of suppressing the auxiliary depletion on both sides of the substrate and deep dielectric trenches on the charge balance of the three-dimensional superjunction structure while suppressing the doping concentration of the region, and introducing the High K dielectric trench to avoid the substrate and deep dielectric while achieving multidimensional depletion. Effect of auxiliary depletion on both sides of trench on charge balance of three-dimensional superjunction structure

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Super junction MOS power semiconductor device and preparation method thereof
  • Super junction MOS power semiconductor device and preparation method thereof
  • Super junction MOS power semiconductor device and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0103] This embodiment provides a super junction LDMOS device, the cell structure of which is as follows figure 2 as shown, figure 2 The schematic diagrams of the cross-sectional structure of the cellular structure along the AB line and the CD line are shown in Fig. image 3 with 4 As shown, the cellular structure of the superjunction LDMOS device includes a bottom-up substrate electrode 15, a substrate, an N-type buffer layer 12, and an N-type drift region 10; one side of the surface of the N-type drift region 10 has a trench gate structure , the trench gate structure includes a trench gate electrode 1 and a trench gate dielectric layer 2 on its side and bottom surface; the other side of the surface of the N-type drift region 10 has an N-type drain region 9, and the upper surface of the N-type drain region 9 has a metal There is a deep dielectric trench 4 in the N-type drift region 10 between the trench gate structure and the N-type drain region 9, and the top layer of th...

Embodiment 2

[0107] This embodiment provides a super junction LDMOS device, the cell structure of which is as follows Figure 5 as shown, Figure 5 The schematic diagrams of the cross-sectional structure of the cellular structure along the AB line and the CD line are shown in Fig. Image 6 with 7 shown. In this embodiment, on the basis of Embodiment 1, a first field plate 401 and a second field plate 402 are introduced into the deep dielectric trench 4 along the direction in which the N-type pillar regions 10 and the P-type pillar regions 11 are alternately arranged. The longitudinal depths of the first field plate 401 and the second field plate 402 are smaller than the longitudinal depth of the deep dielectric trench 4 . The thickness of the dielectric layer between the first field plate 401 and the second field plate 402 and the edge of the deep dielectric trench 4 can be adjusted, that is, a field plate with a uniform dielectric layer thickness can be used, a stepped field plate can ...

Embodiment 3

[0110] This embodiment provides a super junction LDMOS device, the cell structure of which is as follows Figure 8 as shown, Figure 8 The schematic diagrams of the cross-sectional structure of the cellular structure along the AB line and the CD line are shown in Fig. Figure 9 with 10 As shown, this embodiment is based on Embodiment 1. In the N-type drift region 10 below the N-type drain region 9, a side N-type buffer layer 16 close to the side wall of the deep dielectric trench 4 is also provided. The doping concentration of the N-type buffer layer 16 is not less than the doping concentration of the N-pillar 10 . The doping concentration of the side N-type buffer layer 16 can be uniformly doped, or can be gradually decreased from top to bottom.

[0111] The introduction of the side N-type buffer layer 16 can suppress the impact of auxiliary depletion on the charge balance of the superjunction structure caused by the difference in potential on both sides of the deep trench...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
Thicknessaaaaaaaaaa
Login to View More

Abstract

The present invention provides a super junction MOS power semiconductor device and a preparation method thereof, belonging to the technical field of power semiconductor devices. On the basis of a traditional deep groove MOS device, a three-dimensional super junction structure is formed in a drift region to overcome the problem that the drift region cannot be completely exhausted due to a thick drift region and a deep groove, the on resistance is reduced while improving the pressure-resistant properties of the device, the electric field regulation effect is provided with no need for extending the gate structure to an oxygen buried layer so as to reduce the gate capacitance and improve the device switching speed. A buffer layer and a High K medium region are further introduced to ensure thecharge balance feature of the three-dimensional super junction structure while improving the dosage concentration of the drift region, and the device performance and reliability are further improved.The device has a U-shaped conductive channel to achieve idea super junction features so that the device is high in withstand voltage, low in specific on-resistance and fast in switching speed, the chip area is saved and the cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, and in particular relates to a super-junction MOS power semiconductor device and a preparation method thereof. Background technique [0002] With the rapid development of electronic technology, LDMOS devices are widely used in high-voltage power integrated circuits due to their good thermal stability, strong blocking ability, small on-resistance, high gain, low noise and compatibility with CMOS technology. For traditional LDMOS devices, in order to increase their breakdown voltage, it is necessary to increase the length of their drift region. However, this will increase the on-resistance of the device, increase the power consumption and chip area, and increase the cost. In order to solve the above problems, the industry has proposed a deep trench LDMOS structure, the cell structure of which is as follows figure 1 shown. Compared to the traditional LDMOS structure, figure 1 ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H01L29/06H01L21/336H01L29/78
CPCH01L29/0634H01L29/66681H01L29/7816H01L29/7824H01L29/0653H01L29/7825H01L29/407
Inventor 张金平王康赵阳罗君轶刘竞秀李泽宏张波
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA