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A kind of preparation method of p-type low off-angle silicon carbide epitaxial wafer

A technology of low-off-angle silicon carbide and epitaxial wafers, applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve problems such as difficult control of surface roughness, achieve extended cleaning cycle, improve growth efficiency, and reduce growth costs Effect

Active Publication Date: 2018-12-18
GLOBAL ENERGY INTERCONNECTION RES INST CO LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] According to the development status of the wafer size, people pay more and more attention to the epitaxial growth of SiC on the substrate with low off-angle orientation, and according to the literature reports, the surface roughness of SiC low-off-angle epitaxial growth is difficult to control. In terms of devices, an ultra-thick silicon carbide epitaxial layer is required

Method used

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  • A kind of preparation method of p-type low off-angle silicon carbide epitaxial wafer
  • A kind of preparation method of p-type low off-angle silicon carbide epitaxial wafer
  • A kind of preparation method of p-type low off-angle silicon carbide epitaxial wafer

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Embodiment 1

[0040] A method for preparing a P-type low off-angle silicon carbide epitaxial wafer with a thickness of 15 μm, comprising the following steps:

[0041] 1) On-line etching substrate: Prepare a 4H-SiC substrate with an off angle of 4°, vacuumize it, and feed in hydrogen gas at a flow rate of 40L / min and HCl at a flow rate of 5L / min. The pressure in the reaction chamber is 40mbar and the temperature is 1680°C , for 5 minutes;

[0042] 2) Growth of the buffer layer: Stop feeding HCl, lower the temperature to 1650°C, and feed SiH with a flow rate of 6mL / min 4 and 3mL / min of C 3 h 8 , using TMA with a flow rate of 1500mL / min as a dopant and a growth pressure of 40mbar to grow a buffer layer with a thickness of 0.4μm;

[0043] 3) Growth of epitaxial layer

[0044] a Growth: 40L / min flow rate of hydrogen, 10mL / min SiH 4 and 5mL / min of C 3 h 8 Pass into the reaction chamber, keep the temperature at 1650°C and the pressure at 40mbar, and use TMA at a flow rate of 800mL / min as th...

Embodiment 2

[0049] A P-type low off-angle thickness 30 μm silicon carbide epitaxial preparation method, comprising the following steps:

[0050] 1) On-line etching of the substrate: prepare a 4H-SiC substrate with an off-angle of 2°, vacuumize it, feed in hydrogen gas at a flow rate of 40L / min and HCl at a flow rate of 5L / min, the pressure in the reaction chamber is 40mbar, and the temperature is 1680°C , for 5 minutes;

[0051] 2) Growth of the buffer layer: Stop feeding HCl, lower the temperature to 1650°C, and feed SiH with a flow rate of 6mL / min 4 and 3mL / min of C 3 h 8 , using TMA with a flow rate of 1500mL / min as a dopant, and a growth pressure of 40mbar, to grow a buffer layer with a thickness of 1 μm;

[0052] 3) Growth of epitaxial layer

[0053] a Growth: 40L / min flow rate of hydrogen, 10mL / min SiH4 and 5mL / min of C 3 h 8 Pass into the reaction chamber, keep the temperature at 1650°C and the pressure at 40mbar, and use TMA at a flow rate of 800mL / min as the dopant to grow ...

Embodiment 3

[0061] A P-type low off-angle thickness 80 μm silicon carbide epitaxial preparation method, comprising the following steps:

[0062] 1) On-line etching substrate: Prepare a 4H-SiC substrate with an off angle of 4°, vacuumize it, and feed in hydrogen gas at a flow rate of 40L / min and HCl at a flow rate of 5L / min. The pressure in the reaction chamber is 40mbar and the temperature is 1680°C , for 5 minutes;

[0063] 2) Growth of the buffer layer: Stop feeding HCl, lower the temperature to 1650°C, and feed SiH with a flow rate of 6mL / min 4 and 3mL / min of C 3 h 8 , using TMA with a flow rate of 1500mL / min as a dopant and a growth pressure of 40mbar to grow a buffer layer with a thickness of 1.5μm;

[0064] 3) Growth of epitaxial layer

[0065] a Growth: 40L / min flow rate of hydrogen, 10mL / min SiH 4 and 5mL / min of C 3 h 8 Pass into the reaction chamber, keep the temperature at 1650°C and the pressure at 40mbar, and use TMA at a flow rate of 800mL / min as the dopant to grow a 1...

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Abstract

The invention provides a preparation method of a P-type small drift-angle silicon carbide epitaxial wafer. The method includes the following steps: preparing a substrate, etching the substrate on-line, making a buffer layer grow, and making an epitaxial layer grow, wherein the growth of the epitaxial layer adopts a method of growing, etching, blowing and re-growing. During the growth of a P-type small drift-angle silicon carbide epitaxial wafer, the base dislocation density is effectively reduced, and deposits inside a cavity are minimized. Therefore, triangle defects caused by foreign particles are minimized, the quality of a silicon carbide epitaxial material is improved, the processing cost is low, and thus the method is suitable for industrial production.

Description

technical field [0001] The invention relates to a method for preparing a semiconductor material, in particular to a method for preparing a P-type low off-angle silicon carbide epitaxial wafer. Background technique [0002] Silicon carbide has good chemical inertness, high temperature resistance and radiation resistance, and has great application potential in the field of high-power power electronics. Silicon carbide is a homogenous polymorphic material, and more than 250 crystalline forms have been discovered. Among the many SiC polytypes, 4H-SiC is known for its large bandgap (3.26eV) and high mobility (900cm 2 / Vs) and smaller anisotropy are considered to be more suitable for the manufacture of high-power and high-backvoltage electronic devices. [0003] The essence of the current SiC 8° and 4° off-angle epitaxial growth "step control epitaxy" technology is the flow of atomic steps. This technology not only effectively controls the crystal form of SiC, but also reduces ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L21/02
CPCH01L21/02378H01L21/0243H01L21/02447H01L21/02529H01L21/02634H01L21/02661
Inventor 钮应喜杨霏
Owner GLOBAL ENERGY INTERCONNECTION RES INST CO LTD