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A silicon carbide vdmos device and manufacturing method thereof

A technology of silicon carbide and silicon carbide regions, which is applied in semiconductor/solid-state device manufacturing, semiconductor devices, electrical components, etc., and can solve problems such as high power loss, high system cost, and rising system cost

Active Publication Date: 2020-03-17
HANGZHOU SILICON-MAGIC SEMICON TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Silicon carbide VDMOS devices generally need to work together with an anti-parallel diode in traditional inverter circuits, chopper circuits and other circuit applications. There are usually the following two methods: one is: directly use the device Pbase, N-region and N+ lining The parasitic PIN diode formed at the bottom; due to the junction voltage drop of about 3V at the silicon carbide PN junction, if the PIN diode is used directly, it will lead to a large forward conduction voltage drop, power loss and low circuit application efficiency, which not only This leads to reliability problems caused by device heating, and attention should also be paid to the waste of energy resources; the second is to use a fast recovery diode (FRD) in antiparallel to the outside of the device, but this method causes the rise of system cost and volume reduction. Problems such as increasing the size and reducing reliability after increasing the metal connection are not conducive to the promotion of silicon carbide VDMOS devices in applications such as traditional inverter circuits and chopper circuits.
[0007] In summary, how to realize the wide application of silicon carbide VDMOS devices in inverter circuits, chopper circuits and other circuits, and solve the problems of high power loss, low work efficiency, and high system cost in existing applications has become an important issue in this field. Problems that technicians need to solve urgently

Method used

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  • A silicon carbide vdmos device and manufacturing method thereof
  • A silicon carbide vdmos device and manufacturing method thereof
  • A silicon carbide vdmos device and manufacturing method thereof

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Experimental program
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Embodiment 1

[0104] A kind of silicon carbide VDMOS device provided by the present invention, the cell structure of its basic structure is as follows figure 2 shown. It includes a metal drain electrode 10 arranged sequentially from bottom to top with a thickness of about 0.5-6 μm and a doping concentration of 1×10 18 cm -3 ~1×10 19 cm -3 , N with a thickness of 50-200 μm + The substrate 9 has a thickness of 15-18 μm and a doping concentration of about 1×10 15 cm -3 ~5×10 16 cm -3 N - Epitaxial layer 8; above the N- epitaxial layer 8 has a doping concentration of 1×10 17 ~7×10 17 cm -3 1. Implant the first Pbase region 7 with a depth of about 0.5-1 μm, and the other end of the upper layer has a second Pbase region 71 with the same parameters; the first Pbase region 7 has mutually independent doping concentrations of 1×10 19 ~1×10 20 cm -3 , implanting the first N with a depth of about 0.3-0.5 μm + The source region 6 and the doping concentration are about 3×10 19 ~1×10 20 c...

Embodiment 2

[0106] Such as image 3 As shown, except that the P-type silicon carbide region 13 is replaced by a dielectric layer 15 with a thickness of 0.02-0.50 μm, the rest of the structure of this embodiment is the same as that of Embodiment 1. Compared with Example 1, the dielectric layer 15 is able to P + The polysilicon layer 12 plays the role of electric field shielding and protection, thereby improving the breakdown voltage and reliability of the device, and reducing the reverse leakage current.

Embodiment 3

[0108] Such as Figure 4 As shown, except that the width of the P-type silicon carbide region 13 is larger than P + The width of the polysilicon layer 12 and the P-type silicon carbide region 13 in N - Except for the depth inside the epitaxial layer 8 , the rest of the structure of this embodiment is the same as that of Embodiment 1.

[0109] Compared with Embodiment 1, this embodiment further improves the electric field shielding effect of the P-type silicon carbide region 13, further improves the breakdown voltage and reliability of the device, and reduces the reverse leakage current.

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Abstract

The invention discloses a silicon carbide VDMOS device and a manufacturing method thereof, belonging to the technical field of power semiconductors. The present invention etches the trench on the surface of the JFET region of the traditional silicon carbide VDMOS device, introduces P-type doping at the bottom of the trench, and forms a polysilicon layer in the trench at the same time, so that the polysilicon layer contacts the sidewall of the trench to form Si / SiC heterojunction. The invention integrates a diode inside the device, which has the advantages of low conduction voltage, fast switching speed and good reverse recovery characteristics in the diode working mode, high breakdown voltage, small gate capacitance and good switching performance in the MOS working mode. The advantage of speed. The device structure proposed by the invention optimizes its application in the fields of inverter circuits, chopper circuits, etc., and has the advantages of simple process and compatibility with traditional silicon carbide VDMOS device processes.

Description

technical field [0001] The invention belongs to the technical field of power semiconductors, and in particular relates to a silicon carbide VDMOS device and a manufacturing method thereof. Background technique [0002] Since the beginning of the 21st century, the world's energy production and consumption are still dominated by fossil energy, and fossil energy will remain the energy basis for human survival and development for a relatively long period of time. However, fossil energy will eventually be exhausted, and it is easy to cause environmental pollution problems, and the resulting problems of environment and sustainable development are difficult problems that human beings must face. Therefore, as an important energy source that can be used by human beings - electric energy, the improvement of its efficiency is an important solution to the world's energy problems. [0003] The power system is a necessary way for human beings to use electric energy and improve the effici...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L29/78H01L29/16H01L29/06H01L21/336
CPCH01L29/0684H01L29/1608H01L29/66068H01L29/7802H01L29/7804H01L29/165
Inventor 张金平邹华刘竞秀李泽宏任敏张波
Owner HANGZHOU SILICON-MAGIC SEMICON TECH CO LTD