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Silicon carbide epitaxial material and preparing method thereof

An epitaxial material, silicon carbide technology, applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve problems such as difficulty in achieving resistivity lower than 0.5Ωcm, inability to realize PT-IGBT devices, and inability to obtain epitaxial materials, etc. Achieve improved performance and reliability, low resistivity, and fewer defects in the drift region

Active Publication Date: 2015-03-25
STATE GRID CORP OF CHINA +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, when silicon carbide crystals are grown by the traditional sublimation method, because the activation energy of 4H-SiC is too large when B-doped or Al-doped, it is difficult to achieve a level of resistivity lower than 0.5Ωcm, as high as 200Ωcm or higher, and cannot be used. To make P+ silicon carbide substrates, and thus cannot obtain epitaxial materials with N-base regions, so it is currently a technical difficulty that PT-IGBT devices cannot be realized based on SiC materials

Method used

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  • Silicon carbide epitaxial material and preparing method thereof
  • Silicon carbide epitaxial material and preparing method thereof
  • Silicon carbide epitaxial material and preparing method thereof

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Embodiment 1

[0033] Such as Figure 4 As shown, a silicon carbide epitaxial material according to the present invention includes a P+ support layer, an N+ substrate layer and an N-drift layer arranged from bottom to top.

[0034] The steps of the above silicon carbide epitaxial material manufacturing method are as follows:

[0035] a. Choose a diameter of 4 inches, a thickness of 350 μm, a dopant of nitrogen, and a doping concentration of 6×10 17 cm -3 N+ type substrate;

[0036] b. Using a boron carbide abrasive slurry with a pH value of 9 and a diameter of less than 0.1 μm, the back surface of the selected substrate is treated with a chemical mechanical polishing method to reduce the back surface roughness to within 0.1 nm;

[0037] c. The dopant is trimethylaluminum, and the doping concentration is 4×10 19 cm -3 , under the conditions of a deposition temperature of 1650°C and a growth rate of 72 μm / h, the growth of the P+ supporting layer is completed by chemical vapor deposition o...

Embodiment 2

[0043] Such as Figure 4 As shown, the silicon carbide epitaxial material described in the present invention includes a P+ support layer, an N+ substrate layer and an N-drift layer arranged from bottom to top.

[0044] Such as Figure 1-4 As shown, the steps of the above silicon carbide epitaxial material manufacturing method are as follows:

[0045] a. Choose a diameter of 6 inches, a thickness of 350 μm, a dopant of nitrogen, and a doping concentration of 3×10 17 cm -3 N+ type substrate;

[0046] b. Using a boron carbide grinding slurry with a pH value of 9 and a diameter of less than 0.2 μm, the back surface of the selected substrate is treated with a chemical mechanical polishing method to reduce the roughness of the back surface to within 0.1 nm;

[0047] c. The dopant is trimethylaluminum, and the doping concentration is 6×10 19 cm -3 , under the conditions of a deposition temperature of 1650°C and a growth rate of 72 μm / h, homogeneous silicon carbide epitaxial gro...

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Abstract

The invention provides a silicon carbide epitaxial material. The material comprises an N+ silicon carbide single crystal substrate layer, a P+ supporting layer located under the substrate, and an N- drifting layer located on the surface of the substrate. The method for preparing the material comprises the steps of (1) preparing the N+ substrate, (2) conducting chemico-mechanical polishing on the back side of the N+ substrate, (3) growing the P+ supporting layer on the back side, (4) thinning the front side of the N+ substrate, (5) conducting chemico-mechanical polishing on the front side, and (6) growing the N- drifting layer on the front side. Compared with a traditional silicon carbide epitaxial material, the silicon carbide epitaxial material has the advantages that the electrical resistivity of the P+ supporting layer is low, the uniformity of the P+ supporting layer is high, and requirements of high-voltage devices are met; meanwhile, the number of defects is small, manufacturing is easy, process repeatability is high, and industrial production is facilitated.

Description

technical field [0001] The invention relates to a semiconductor material, in particular to a silicon carbide epitaxial material and a preparation method thereof. Background technique [0002] Silicon carbide (SiC) is the third-generation semiconductor material developed after the first-generation semiconductor materials silicon and germanium and the second-band semiconductor materials gallium arsenide and indium phosphide. The band gap of silicon carbide is 2 to 3 times that of silicon and gallium arsenide, which enables semiconductor devices to work at temperatures above 500°C and has the ability to emit blue light; silicon carbide materials are higher than silicon and gallium arsenide. An order of magnitude high breakdown electric field determines the high voltage and high power performance of silicon carbide semiconductor devices; high saturated electron drift velocity and low dielectric constant determine the high frequency and high speed performance of the device; the t...

Claims

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Application Information

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IPC IPC(8): H01L29/06H01L21/205
Inventor 钮应喜杨霏温家良陈新
Owner STATE GRID CORP OF CHINA