Seed crystal with high surface cleanliness and cleaning method thereof

A surface cleaning and seeding technology, which is applied to the cleaning methods, cleaning methods and utensils, chemical instruments and methods using gas flow, etc., can solve the problem of destroying the growth information of the seed crystal growth surface, increasing the roughness of the seed crystal growth surface, Problems such as a large number of residual particles, to achieve the effect of reducing the number of residual particles, avoiding damage to the seed crystal, and reducing the number of particles

Active Publication Date: 2021-10-22
SICC CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The processing of the seed crystal substrate improves the consistency of the quality of the seed crystal growth surface and facilitates the growth of large-scale silicon carbide single crystals. However, the cutting, grinding and polishing process during the processing of the seed crystal growth surface inevitably destroys the quality of the seed crystal growth surface. The original growth information, and there will be a large number of particles remaining on the growth surface of the seed crystal, which cannot be effectively removed by traditional cleaning methods, especially the residual particles of the processed raw materials are strongly adsorbed on the growth surface of the seed crystal. The existence of these particles increases the roughness of the growth surface of the seed crystal. Seriously affect the quality of nucleation and induce crystal defects such as micropipes, polytypes, dislocations, and stacking faults

Method used

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  • Seed crystal with high surface cleanliness and cleaning method thereof
  • Seed crystal with high surface cleanliness and cleaning method thereof
  • Seed crystal with high surface cleanliness and cleaning method thereof

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Experimental program
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Effect test

Embodiment 1

[0097] refer to Figure 1-5 , the embodiment of the present application discloses a cleaning device for improving the cleanliness of the seed crystal, the device includes a housing 10 and a seed crystal tray 20, the side wall of the housing 10 is provided with a plurality of seed crystal inlets 14 along the axial direction of the housing 10 , the top or bottom of the housing 10 is provided with an air inlet 11, and at least one air outlet 12 is correspondingly arranged on the side wall of the housing 10 close to each seed crystal inlet 14, and the air outlet 12 and the air inlet 11 are located at the seed crystal inlet 14 The same side of the same side; the seed crystal tray 20 is used to fix the seed crystal 21, and the seed crystal tray 20 is inserted into the seed crystal inlet 14, so that the seed crystal 21 and the air inlet 11 side casing 10 enclose the gas cleaning chamber 13, and the clean gas The gas is blown into the gas cleaning chamber 13 from the gas inlet 11 , fl...

Embodiment 2

[0122] This embodiment provides a cleaning method for improving the cleanliness of the surface of the seed crystal, wherein the seed crystal is prepared from the same cutting, grinding and polishing process. This method is carried out using the cleaning device of any embodiment in Example 1. The cleaning The method comprises the steps of:

[0123] Preparation stage: fix multiple seed crystals to be cleaned in the housing;

[0124] Cleaning stage: Open the air inlet, use the heating coil to heat the cleaning gas to 150-1000°C, the heated cleaning gas will clean the long crystal surface of silicon carbide for at least 30 minutes, then close the air inlet, and take the cleaned seed crystal Next, put back the seed tray that does not carry the seed crystal to clean the next seed crystal, and repeat the above steps until all the seed crystals are cleaned.

[0125] Preferably, a cleaning method for improving the cleanliness of the seed crystal comprises the following steps:

[0126] ...

Embodiment 3

[0146] A silicon carbide single crystal is prepared from the cleaned seed crystal in Example 2 above, and the preparation method comprises the following steps:

[0147] (1) Place the seed crystal and silicon carbide raw materials in the crystal growth furnace and seal them, vacuumize the crystal growth furnace and introduce inert gas to remove impurities;

[0148] (2) The high-purity inert gas is introduced into the furnace body, so that the pressure in the crystal growth furnace rises to 1×10 4 -1×10 5 Pa, continue to feed high-purity inert gas and keep the pressure constant, and control the temperature in the crystal growth furnace to rise to 2000K-2300K;

[0149] (3) Control the crystal growth temperature to 2200K-2800K, the crystal growth pressure to 500-3000Pa, and hold the time for 50-100h to obtain silicon carbide single crystals 1#-6# and comparative silicon carbide single crystals D1#-D2#.

[0150] Micropipes, polytypes, and dislocations of the prepared silicon carb...

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Abstract

The invention discloses a seed crystal with high surface cleanliness and a cleaning method thereof, and belongs to the technical field of semiconductor material cleaning. After a seed crystal is cleaned by using the cleaning method, the number of particles on the growth surface of the seed crystal can be reduced, the surface quality of the seed crystal can be improved, the quality of the crystal produced by using the seed crystal is good, and the crystal defects such as microtubules, multiple types, dislocation and the like can be effectively reduced. According to the invention, on the growth surface of the seed crystal, the number of particles with the particle size of more than 1 [mu]m is less than 10, the number of particles with the particle size of 0.5-1 [mu]m is less than 20, the number of particles with the particle size of 0.1-0. 5 [mu]m is less than 30, and the number of particles with the particle size of 0.02-0.1 [mu]m is less than 70.

Description

technical field [0001] The application relates to a seed crystal with high surface cleanliness and a cleaning method thereof, belonging to the technical field of semiconductor material cleaning. Background technique [0002] Silicon carbide is a typical wide bandgap semiconductor material and one of the representatives of the third generation of semiconductor materials after silicon and gallium arsenide. Silicon carbide materials have excellent characteristics such as high thermal conductivity, high breakdown field strength, and high saturation electron mobility, and have become one of the popular materials for preparing high-temperature, high-frequency, high-power and radiation-resistant devices. [0003] The most widely used method for silicon carbide crystal growth is the physical vapor transport method, followed by the liquid phase method and the chemical vapor transport method. The above growth methods to prepare high-quality silicon carbide substrates are inseparable ...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C30B29/36C30B33/00B08B5/02B08B13/00C30B23/00C30B25/00
CPCC30B29/36C30B33/00B08B5/02B08B13/00C30B23/00C30B25/00
Inventor李加林刘星张宁姜岩鹏刘家朋
OwnerSICC CO LTD