阅读说明：本技术 碳化硅粉体、其制备方法和应用及反应装置 (Silicon carbide powder, preparation method and application thereof, and reaction device ) 是由 邓树军 张洁 付芬 于 2020-12-30 设计创作，主要内容包括：本发明公开了碳化硅粉体、其制备方法和应用及反应装置,涉及半导体材料技术领域。碳化硅粉体的制备方法以气态硅源和气态碳源为原料,在800-2400℃的条件下反应生成碳化硅,并在具有发热功能的基材上进行沉积。发明人创造性地利用具有发热功能的基材进行碳化硅的沉积,其有效聚集了生成的碳化硅,有利于制备形成粒径更大的碳化硅粉体。本发明实施例中的制备方法能够显著提升碳化硅的生产效率,可以实现大规模工业化生产,制备得到的碳化硅粉体可以用于碳化硅晶体生长。(The invention discloses silicon carbide powder, a preparation method, application and a reaction device thereof, and relates to the technical field of semiconductor materials. The preparation method of the silicon carbide powder takes a gaseous silicon source and a gaseous carbon source as raw materials, the silicon carbide powder is generated by reaction at 800-2400 ℃, and the silicon carbide powder is deposited on a base material with a heating function. The inventor creatively utilizes the substrate with the heating function to deposit the silicon carbide, effectively gathers the generated silicon carbide and is beneficial to preparing and forming silicon carbide powder with larger grain diameter. The preparation method provided by the embodiment of the invention can obviously improve the production efficiency of silicon carbide, can realize large-scale industrial production, and the prepared silicon carbide powder can be used for growth of silicon carbide crystals.)

1. A preparation method of silicon carbide powder is characterized in that a gaseous silicon source and a gaseous carbon source are used as raw materials, silicon carbide is generated by reaction at 800-2400 ℃, and deposition is carried out on a base material with a heating function.

2. The method for preparing silicon carbide powder according to claim 1, wherein the reaction temperature is 1000-;

preferably, the reaction time is 10-300h, more preferably 150-250 h;

preferably, the molar ratio of silicon to carbon in the mixed gas composed of the gaseous silicon source and the gaseous carbon source is 1: 0.8-1.2.

3. The method for producing the silicon carbide powder according to claim 1, wherein the gaseous silicon source is silane.

4. The method for producing the silicon carbide powder according to claim 1 or 3, wherein the gaseous carbon source is at least one selected from the group consisting of methane, ethane, propane, and ethylene.

5. The method for producing a silicon carbide powder according to claim 1, wherein the obtained crystal is crushed after the completion of the reaction;

preferably, after the disruption, sorting and washing are performed.

6. The method for producing a silicon carbide powder according to claim 1, wherein the reaction for producing silicon carbide is carried out under vacuum conditions;

preferably, the base material with the heat-generating function is a rod-shaped structure; more preferably, the rod body with the heat generating function is a resistance heating rod;

more preferably, the resistance heating rod is made of any one of pure silicon, graphite and silicon carbide.

7. The method for preparing silicon carbide powder according to claim 6, wherein the reaction apparatus for producing silicon carbide comprises a reaction chamber, the resistance heating rod is located in the reaction chamber, a first electrode column and a second electrode column are respectively arranged at two ends of the resistance heating rod, the first electrode column is connected to the inner wall of the top of the reaction chamber, and the second electrode column is connected to the inner wall of the bottom of the reaction chamber; the top of the reaction chamber is provided with a raw material gas inlet, and the bottom of the reaction chamber is provided with a tail gas outlet;

preferably, the resistance heating rod is a plurality of rods.

8. A silicon carbide powder produced by the production method according to any one of claims 1 to 7;

preferably, the silicon carbide powder is rod-shaped.

9. Use of the silicon carbide powder of claim 8 in the growth of a silicon carbide crystal.

10. The reaction device for the preparation method of any one of embodiments 1 to 7 is characterized by comprising a reaction chamber, wherein the reaction chamber is provided with a gaseous raw material inlet, and a substrate with a heating function is arranged in the reaction chamber;

preferably, the substrate with the heat generating function is a resistance heating rod;

preferably, the resistance heating rod is located in the reaction chamber, a first electrode column and a second electrode column are respectively arranged at two ends of the resistance heating rod, the first electrode column is connected to the inner wall of the top of the reaction chamber, and the second electrode column is connected to the inner wall of the bottom of the reaction chamber; the top of the reaction chamber is provided with a raw material gas inlet, and the bottom of the reaction chamber is provided with a tail gas outlet;

preferably, the resistance heating rod is a plurality of rods.

Technical Field

The invention relates to the technical field of semiconductor materials, in particular to silicon carbide powder, a preparation method and application thereof and a reaction device.

Background

The silicon carbide single crystal material belongs to the representative of third generation wide band gap semiconductor materials, and has the characteristics of wide forbidden band, high thermal conductivity, high breakdown electric field, high radiation resistance and the like. At present, the growth of silicon carbide single crystal uses physical vapor deposition (PVT) as the main growth mode, and has been proved to be the most mature method for growing SiC crystal. High-purity SiC powder with proper bulk density is taken as a source, the SiC powder is heated to 2300 ℃, and is sublimated and crystallized to form blocky crystals in an inert gas atmosphere such as argon gas.

At present, SiC powder produced in large scale is usually produced by mixing Si powder and C powder and generating SiC powder through a self-propagating synthesis method. The granularity of the powder produced by the method is about 0.1-2mm, the granularity of the powder is small, the output of a single furnace is small, and generally only 5 kg/heat can be realized. Is not suitable for large-scale industrial production.

Disclosure of Invention

The invention aims to provide a preparation method of silicon carbide powder, aims to improve the particle size of the prepared silicon carbide powder and the yield of the silicon carbide powder, and is suitable for large-scale industrial production.

Another object of the present invention is to provide a silicon carbide powder having a large particle size and a low production cost.

The third purpose of the invention is to provide the application of the silicon carbide powder in the growth of silicon carbide crystals.

The technical problem to be solved by the invention is realized by adopting the following technical scheme.

The invention provides a preparation method of silicon carbide powder, which takes a gaseous silicon source and a gaseous carbon source as raw materials, reacts at 800-2400 ℃ to generate silicon carbide, and deposits on a substrate with a heating function.

The invention also provides silicon carbide powder prepared by the preparation method; preferably, the silicon carbide powder is rod-shaped.

The invention also provides the application of the silicon carbide powder in the growth of silicon carbide crystals.

The embodiment of the invention provides a preparation method of silicon carbide powder, which has the beneficial effects that: gaseous silicon source and gaseous carbon source are used as raw materials, and silicon carbide is formed after decomposition at 800-2400 ℃ and deposited on the base material with the heating function. The inventor creatively utilizes the substrate with the heating function to deposit the silicon carbide, effectively gathers the generated silicon carbide and is beneficial to preparing and forming silicon carbide powder with larger grain diameter. The preparation method provided by the embodiment of the invention can obviously improve the production efficiency of silicon carbide, can realize large-scale industrial production, and the prepared silicon carbide powder can be used for growth of silicon carbide crystals.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of a silicon carbide powder reaction apparatus;

FIG. 2 is a schematic top view of the reactor apparatus of FIG. 1.

Icon: 100-a reaction apparatus; 110-a reaction chamber; 120-resistance heating rod; 130-a first electrode column; 140-second electrode column.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following provides a detailed description of the silicon carbide powder, the preparation method and the application thereof, and the reaction apparatus.

The embodiment of the invention provides a preparation method of silicon carbide powder, which takes a gaseous silicon source and a gaseous carbon source as raw materials, reacts at 800-2400 ℃ to generate silicon carbide, and deposits on a substrate with a heating function. Preferably, the base material having a heat generating function has a rod-like structure.

The inventor creatively utilizes the rod body with the heating function to deposit the silicon carbide, effectively gathers the generated silicon carbide and is beneficial to preparing and forming the silicon carbide powder with larger grain diameter. The preparation method in the embodiment of the invention can obviously improve the production efficiency of silicon carbide, can realize large-scale industrial production, can enable the yield of a single rod body structure to reach 100kg, and can obviously improve the production efficiency of silicon carbide powder.

Further, the reaction temperature is 1000-2000 ℃, and 1100-1500 is preferred; the reaction time is 10-300h, preferably 150-250 h. By further controlling the reaction temperature and the reaction time, the reaction efficiency is improved, and the yield of the silicon carbide is further improved.

Further, the gaseous silicon source is silane; the gaseous carbon source is selected from at least one of methane, ethane, propane and ethylene. The gaseous silicon source and the gaseous carbon source are suitable for the preparation method in the embodiment of the invention, and can be decomposed at high temperature to form silicon carbide which is deposited on the rod body structure. The molar ratio of silicon to carbon in the mixed gas composed of the gaseous silicon source and the gaseous carbon source is 1:0.8-1.2, such as 1:0.8, 1:1, 1:1.2, etc.

In a preferred embodiment, the reaction for generating silicon carbide is performed under vacuum, and the reaction under vacuum can effectively avoid side reactions under high temperature conditions, so as to obtain pure silicon carbide powder.

In a preferred embodiment, the rod body with the heat generating function is a resistance heating rod; the resistance heating rod can be made of any one of pure silicon, graphite and silicon carbide, and can be a high-purity silicon rod, a high-purity graphite rod, a SiC polycrystalline rod and the like.

In a preferred embodiment, referring to fig. 1 and 2, a reaction apparatus 100 for producing silicon carbide includes a reaction chamber 110, a resistance heating rod 120 located in the reaction chamber 110, a first electrode column 130 and a second electrode column 140 respectively disposed at two ends of the resistance heating rod 120, the first electrode column 130 connected to a top inner wall of the reaction chamber 110, the second electrode column 140 connected to a bottom inner wall of the reaction chamber 110; the top of the reaction chamber 110 is provided with a raw material gas inlet (not shown), and the bottom of the reaction chamber 110 is provided with a tail gas outlet.

It should be noted that, in the preparation process, a gaseous silicon source and a gaseous carbon source are introduced through the raw material gas inlet, and react in the reaction chamber 110 to generate silicon carbide, which is deposited on the resistance heating rod 120 to gather the silicon carbide powder, and the generated gases such as hydrogen are discharged through the tail gas outlet.

Specifically, the reaction chamber 110 may have a cylindrical structure, and the resistance heating rod 120 is electrically connected to the first electrode column 130 and the second electrode column 140 at both ends thereof to realize heating.

It should be added that the external structure of the reaction chamber 110 can refer to the prior art, which includes a circuit for supplying power to the resistance heating rod 120, a vacuum pump for evacuating the inside of the reaction chamber 110, and the like.

In a preferred embodiment, the number of the resistance heating rods 120 is multiple, and the number of the resistance heating rods 120 can be about 20 by providing multiple resistance heating rods 120 to further increase the yield of a single process.

In some embodiments, after the reaction is completed, the obtained crystals are crushed, either by ordinary crushing or cutting, to reach the desired particle size range. Preferably, after the crushing, sorting and cleaning are performed to remove impurities on the surface, so that pure silicon carbide powder is obtained.

The embodiment of the invention also provides silicon carbide powder, which is prepared by the preparation method; preferably, the silicon carbide powder is rod-shaped. The silicon carbide powder prepared by the preparation method has a larger diameter which can reach 150mm, and is in a form of silicon carbide polycrystal. The prepared silicon carbide powder can be applied to the growth of high-purity SiC crystals and is used for growing the high-purity silicon carbide crystals.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

This embodiment provides a method for preparing silicon carbide powder, which uses the apparatus shown in fig. 1-2 to prepare silicon carbide powder, where 20 resistive heating rods 120 are provided, and the method includes the following specific steps:

after the reaction chamber 110 is vacuumized, the temperature of the resistance heating rod 120 is raised to about 1200 ℃, mixed gas of silane and methane (the molar ratio of silicon to carbon in the mixed gas is 1:1) is introduced into the reaction chamber 110, the mixed gas is decomposed on the resistance heating rod 120 to generate silicon carbide, the silicon carbide is deposited on the resistance heating rod 120, and after 200 hours of growth, a large-diameter silicon carbide rod is grown on the resistance heating rod.

Example 2

This embodiment provides a method for preparing silicon carbide powder, which uses the apparatus shown in fig. 1-2 to prepare silicon carbide powder, where 20 resistive heating rods 120 are provided, and the method includes the following specific steps:

after the reaction chamber 110 is vacuumized, the temperature of the resistance heating rod 120 is raised to about 1500 ℃, mixed gas of silane and methane (the molar ratio of silicon to carbon in the mixed gas is 1:1) is introduced into the reaction chamber 110, the mixed gas is decomposed on the resistance heating rod 120 to generate silicon carbide, the silicon carbide is deposited on the resistance heating rod 120, and after 150 hours of growth, a large-diameter silicon carbide rod is grown on the resistance heating rod.

Example 3

This embodiment provides a method for preparing silicon carbide powder, which uses the apparatus shown in fig. 1-2 to prepare silicon carbide powder, where 20 resistive heating rods 120 are provided, and the method includes the following specific steps:

after the reaction chamber 110 is vacuumized, the temperature of the resistance heating rod 120 is raised to about 2000 ℃, mixed gas of silane and methane (the molar ratio of silicon to carbon in the mixed gas is 1:1) is introduced into the reaction chamber 110, the mixed gas is decomposed on the resistance heating rod 120 to generate silicon carbide, the silicon carbide is deposited on the resistance heating rod 120, and after the silicon carbide grows for 250 hours, a large-diameter silicon carbide rod grows on the resistance heating rod.

Example 4

The present embodiment provides a method for preparing silicon carbide powder, which is different from embodiment 1 in the following parameter control: the resistance heating rod 120 temperature was 800 ℃.

Example 5

The present embodiment provides a method for preparing silicon carbide powder, which is different from embodiment 1 in the following parameter control: the resistance heating rod 120 temperature was 2400 ℃.

Example 6

The present embodiment provides a method for preparing silicon carbide powder, which is different from embodiment 1 in the following parameter control: the reaction time was 10 h.

Example 7

The present embodiment provides a method for preparing silicon carbide powder, which is different from embodiment 1 in the following parameter control: the reaction time is 300 h.

Example 8

The present embodiment provides a method for preparing silicon carbide powder, which is different from embodiment 1 in the following parameter control: methane was replaced by ethylene.

Comparative example 1

The comparative example provides a preparation method of silicon carbide powder, which adopts the traditional process, mixes Si powder and C powder, generates SiC powder by a self-propagating synthesis method, and specifically selects preferred values for specific parameters to test according to the prior art such as research progress of the synthesis process of the SiC powder for growing single crystals.

Comparative example 2

This comparative example provides a method for producing a silicon carbide powder, which is different from example 1 only in that: the resistance heating rod 120 was at a temperature of 700 c, at which point the temperature was too low to produce substantially no output.

Comparative example 3

This comparative example provides a method for producing a silicon carbide powder, which is different from example 1 only in that: the temperature of the resistance heating rod 120 is 2600 ℃, and the resistance heating rod is abnormally damaged due to overhigh temperature.

Test example 1

The silicon carbide rods prepared in examples 1 to 6 and comparative examples 1 to 4 were tested for diameter, height and yield of a single resistance heating rod.

The results show that: the silicon carbide powder prepared in example 1 had a rod-like structure with a diameter of 150mm, a height of 2000mm and a single-strand yield of 100 kg.

The silicon carbide powder prepared in example 2 had a rod-like structure with a diameter of 135mm and a height of 2000mm, and a single-seed yield of 89 kg.

The silicon carbide powder prepared in example 3 had a rod-like structure, a diameter of 140mm, a height of 2000mm, and a single-strand yield of 96 kg.

The silicon carbide powder prepared in example 4 had a rod-like structure with a diameter of 112mm and a height of 2000mm, and a single-seed yield of 61 kg.

The silicon carbide powder prepared in example 5 had a rod-like structure with a diameter of 123mm, a height of 2000mm and a single-strand yield of 74 kg.

The silicon carbide powder prepared in example 6 had a rod-like structure with a diameter of 32mm, a height of 2000mm and a single-strand yield of 3 kg.

The silicon carbide powder prepared in example 7 had a rod-like structure with a diameter of 156mm, a height of 2000mm and a single-strand yield of 120 kg.

The silicon carbide powder prepared in example 8 had a rod-like structure with a diameter of 130mm, a height of 2000mm and a single-strand yield of 83 kg.

The silicon carbide powder prepared in comparative example 1 had a diameter of 0.1 to 2mm and a single-furnace output of 5 kg/heat.

Comparative example 2, no silicon carbide poly-crystal was grown.

Comparative example 3, the resistance heating rod was damaged.

In summary, the preparation method of the silicon carbide powder provided by the invention takes the gaseous silicon source and the gaseous carbon source as raw materials, and the silicon carbide is formed after decomposition at 800-2400 ℃ and deposited on the substrate with the heating function. The inventor creatively utilizes the substrate with the heating function to deposit the silicon carbide, effectively gathers the generated silicon carbide and is beneficial to preparing and forming silicon carbide powder with larger grain diameter. The preparation method provided by the embodiment of the invention can obviously improve the production efficiency of silicon carbide, can realize large-scale industrial production, and the prepared silicon carbide powder can be used for growth of silicon carbide crystals.

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.