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

High-quality silicon carbide seed crystal, silicon carbide crystal, silicon carbide substrate and preparation method thereof

A technology of high-quality silicon carbide seeds and silicon carbide seeds, applied in chemical instruments and methods, crystal growth, single crystal growth, etc., can solve problems such as poor quality of silicon carbide substrates and affecting applications

Active Publication Date: 2021-07-30
BEIJING TIANKE HEDA SEMICON CO LTD +2
View PDF10 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the quality of SiC substrates produced by the current preparation method is not good enough, which affects its practical application

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
  • High-quality silicon carbide seed crystal, silicon carbide crystal, silicon carbide substrate and preparation method thereof
  • High-quality silicon carbide seed crystal, silicon carbide crystal, silicon carbide substrate and preparation method thereof
  • High-quality silicon carbide seed crystal, silicon carbide crystal, silicon carbide substrate and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0113] About the preparation method of silicon carbide seed crystal :

[0114] The present invention provides a method for preparing a high-quality silicon carbide seed crystal described in the above technical solution, comprising the following steps:

[0115] a) performing the first diameter expansion growth on the primary seed crystal to obtain the primary growth crystal;

[0116] b) processing the primary growth crystal to obtain an intermediate seed crystal containing only diameter-expanding regions;

[0117] c) Performing a second diameter-expanding growth on the intermediate seed crystal to obtain a high-grade seed crystal.

[0118] With regard to step a): the primary seed crystal is first expanded in diameter to obtain a primary growth crystal.

[0119] In the present invention, the type and source of the primary seed crystal are not particularly limited, and it can be a general commercially available SiC seed crystal; the commercially available seed crystal usually...

Embodiment 1

[0243] Example 1: Preparation of SiC seed crystal

[0244] S1. Provide primary seeds: micropipe density 2 / cm 2 , screw dislocation density 1000 / cm 2 , compound dislocation density 50 / cm 2 .

[0245] S2. Carry out the first diameter expansion growth: select the diameter expansion angle as 45°; control the axial temperature gradient in the growth chamber: along the crystal growth direction, the temperature gradually increases from the surface of the seed crystal to the surface of the silicon carbide raw material, and the temperature gradient is 2 °C / cm; the lateral temperature gradient is: the temperature gradually increases from the center of the seed crystal along the radial direction to the edge of the seed crystal, and the temperature gradient is 2°C / cm.

[0246] S3. Cutting the crystal grown in step S2 to obtain an intermediate seed crystal containing an equal diameter region and an enlarged diameter region. It is then processed to obtain a high-quality intermediate see...

Embodiment 2

[0251] Embodiment 2: Preparation of silicon carbide powder

[0252] S1. Graphite powder pretreatment: Put high-purity graphite powder (total impurity content < 10ppm) into a high-temperature furnace, evacuate the furnace and keep the vacuum pump unit working all the time, then raise the temperature in the furnace to 2250°C and keep it for 10 hours; During the above heat preservation process, first turn off the vacuum pump unit, fill it with argon to 50000Pa and keep it for 10 minutes, then turn on the vacuum pump to evacuate the furnace again and keep the vacuum pump unit working all the time. Obtain pretreated graphite powder.

[0253] The boron impurity content of gained pretreatment graphite powder is 5.5 * 10 15 / cm 3 , the aluminum impurity content is 4×10 14 / cm 3 .

[0254] S2. Mix silicon powder and pretreated graphite powder at a mass ratio of 1.00:1, put them into a graphite crucible in a high-temperature furnace, then evacuate the furnace, and then fill the fur...

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
areaaaaaaaaaaa
areaaaaaaaaaaa
areaaaaaaaaaaa
Login to View More

Abstract

The invention provides a high-quality silicon carbide seed crystal, a silicon carbide crystal, a silicon carbide substrate and a preparation method thereof. According to the method, the high-quality silicon carbide seed crystal is prepared, the impurity concentration of the silicon carbide powder, the graphite crucible and the thermal insulation material is controlled, and the high-quality silicon carbide substrate is obtained by combining a certain crystal growth process and a wafer processing mode. The obtained silicon carbide substrate has high crystal quality, extremely low microtube number, extremely low screw dislocation density and extremely low composite dislocation density; meanwhile, the p-type impurity concentration is extremely low, and excellent electrical properties are shown; and the surface quality is high.

Description

technical field [0001] The invention relates to the field of semiconductor materials, in particular to a high-quality silicon carbide seed crystal, a silicon carbide crystal, a silicon carbide substrate and a preparation method thereof. Background technique [0002] Silicon carbide substrate, also known as silicon carbide wafer, is shaped as a circular sheet with a diameter of generally 2 inches, 3 inches, 4 inches, 6 inches and 8 inches, and a thickness of generally between 80 microns and 800 microns. Silicon carbide substrates are very suitable for manufacturing high-power, high-temperature, high-frequency power electronic devices due to their excellent properties such as wide band gap, high thermal conductivity, high breakdown field strength, and high saturation electron drift rate. Energy vehicles, rail transit, aerospace, smart grid and other fields have broad application prospects. [0003] However, if silicon carbide substrates are to be used in large-scale practical...

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
Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/36C30B23/02
CPCC30B29/36C30B23/025
Inventor 彭同华王波赵宁娄艳芳郭钰张贺刘春俊杨建
Owner BEIJING TIANKE HEDA SEMICON CO LTD