High-purity large-size silicon carbide single crystal and preparation process thereof

A silicon carbide single crystal and preparation process technology, applied in the fields of crystal growth science and material science, can solve the problems of difficult product quality control, high manufacturing cost, complicated process, etc., and achieve the effects of large size, low cost and simple process

Inactive Publication Date: 2014-04-30
汪长安
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There are more or less problems in these methods, such as complex process, some require high-purity S

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] Select high-purity (99.99%) SiC powder, sieve according to three grades of 10-30 mesh, 30-80 mesh and 80-200 mesh, and remove fine powder below 200 mesh. According to the accumulation principle of the maximum density, add SiC powders of the above particle sizes according to the mass ratio of 20:45:35, grade and mix, and then put 20 tons of the mixture into the vertical electric arc furnace at one time (the furnace size φ3m ×2.7m). Two ultra-high-power, high-purity, high-strength graphite electrodes are pre-embedded in the furnace. Turn on electricity to raise the temperature until the temperature is 2000°C, and smelt for 36 hours. Then cut off the power and let it cool down naturally for 72 hours. Finally, peel off the outer polycrystalline SiC layer to obtain 132 kg of silicon carbide single crystal with a purity of more than 99.99%, light green, transparent, and a size of more than 25mm.

Embodiment 2

[0024] Select high-purity (99.99%) SiC powder, sieve according to three grades of 10-30 mesh, 30-80 mesh and 80-200 mesh, and remove fine powder below 200 mesh. According to the accumulation principle of the maximum density, add SiC powders of the above particle sizes according to the mass ratio of 30:40:30, grade and mix, and then put 35 tons of the mixture into the vertical electric arc furnace at one time (furnace size φ3m ×2.7m). Three ultra-high-power, high-purity, and high-strength graphite electrodes are pre-embedded in the furnace. Turn on electricity to raise the temperature until the temperature is 2300°C, and smelt for 40 hours. Then cut off the power and let it cool naturally for 100 hours. Finally, peel off the outer polycrystalline SiC layer to obtain 166 kg of silicon carbide single crystal with a purity of more than 99.99%, light green color close to colorless, transparent, and a size of more than 25mm.

Embodiment 3

[0026] Select high-purity (99.99%) SiC powder, sieve according to three grades of 10-30 mesh, 30-80 mesh and 80-200 mesh, and remove fine powder below 200 mesh. According to the accumulation principle of maximum density, add SiC powders of the above-mentioned particle sizes according to the mass ratio of 25:35:40, grade and mix, and then put 45 tons of the mixture into the vertical electric arc furnace at one time (furnace size φ3m ×2.7m). Three ultra-high-power, high-purity, and high-strength graphite electrodes are pre-embedded in the furnace. Turn on electricity to raise the temperature until the temperature is 2500°C, and smelt for 50 hours. Then cut off the power and let it cool naturally for 120 hours. Finally, by peeling off the outer polycrystalline SiC layer, 217 kilograms of silicon carbide single crystals with a purity of more than 99.99%, light green color close to colorless, transparent, and a size of more than 25 mm can be obtained.

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PUM

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Abstract

The invention discloses a high-purity large-size silicon carbide single crystal and a preparation process thereof, and belongs to the field of the material science and technology. The preparation process comprises the steps of taking high-purity SiC powder as the raw material, realizing rational grain composition of the SiC powder different in grain size and obtaining the maximum loading density, next, loading the SiC powder in an ultrahigh-power vertical electric arc furnace, carrying out static smelting at a high temperature and under high pressure, and then growing the high-purity large-size silicon carbide single crystal through recrystallization. The manufacturing method of the high-purity large-size silicon carbide single crystal has the advantages of simple process and low cost, and the prepared silicon carbide single crystal is high in purity (> 99.99%), large in size (greater than or equal to 25mm), colourless to light green and transparent, and has a 3C crystal structure. The preparation process is simple, low in cost, high in efficiency, and advantageous for popularization and application.

Description

technical field [0001] The invention belongs to the field of material science and technology, and relates to crystal growth science and technology, especially a high-purity (>99.99%), large-size (>2 inches) silicon carbide (SiC) single crystal and its preparation process. Background technique [0002] Silicon carbide single crystal has the advantages of large band gap, high thermal conductivity, high carrier saturation migration velocity, high critical breakdown electric field strength, etc. It also has excellent chemical stability and high temperature stability, and is very suitable for making high temperature, Electronic devices with high frequency, radiation resistance, high power and high density integration. In particular, it has an important strategic position in national defense and military affairs, so it is highly valued by all countries. Growing large-diameter, high-quality SiC single crystals is the key to realizing device applications. [0003] Currently ...

Claims

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Application Information

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IPC IPC(8): C30B29/36C30B11/02
Inventor 吕佳成汪长安
Owner 汪长安
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