Gas supply system for preparing pyrolytic boron nitride and gas supply method of gas supply system for preparing pyrolytic boron nitride

Abstract

The invention provides a gas supply system for preparing pyrolytic boron nitride and a gas supply method of the gas supply system for preparing the pyrolytic boron nitride. The gas supply system comprises a furnace body, a plurality of boron trichloride gas supply bottles, a plurality of ammonia gas supply bottles and a shielding gas supply bottle group, wherein a first gas inlet and a second gasinlet are arranged on the furnace body, the plurality of boron trichloride gas supply bottles communicate with the first gas inlet in parallel, the plurality of ammonia gas supply bottles communicatewith the second gas inlet in parallel, and the shielding gas supply bottle group communicates with a first main pipeline, a first branch pipeline, a second main pipeline and a second branch pipeline.The plurality of boron trichloride gas supply bottles and the plurality of ammonia gas supply bottles are arranged in parallel, so that stable, safe and continuous gas supply is ensured, and before and after chemical vapor deposition, the pipelines can be purged by using the shielding gas supply bottle group, so that the influence of gas with an oxidizing function on chemical vapor deposition reaction and corrosion of gas residues to the pipeline are prevented, and the quality of a pyrolytic boron nitride product is improved.

Description

technical field [0001] The invention relates to the technical field of chemical vapor deposition, in particular to a gas supply system and a gas supply method for preparing pyrolytic boron nitride. Background technique [0002] Chemical vapor deposition technology mainly uses one or several gas-phase compounds or simple substances containing thin film elements to perform chemical reactions on the surface of the substrate to form thin films. The preparation of pyrolytic boron nitride is to use chemical vapor deposition technology. The high-purity raw material gases BCl3, NH3 and carrier gas (such as N2) are passed into the chemical vapor deposition furnace in a certain proportion. The temperature of the reaction chamber is as high as 2000 ° C, and According to the following chemical equation: BCl3+NH3=BN+3HCl. Among them, the generated BN accumulates on the substrate to form the desired product, which can be obtained after demoulding. [0003] The chemical vapor deposition ...

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Problems solved by technology

If the air flow fluctuates greatly, the chemical vapor deposition reaction is unstable, resulting in unstable deposition rate, uneven coating, and poor bonding of coating materials

[0005]At the same time, in the raw material gas used, BCl3 is very easy to hydrolyze and is acidic. If there is a certain amount of residue in the pipeline, it will It will be corrosive to the gas pipeline equipment, which not only affects the service life of the pipeline, but also the impurities generated by corrosion and rust are easily brought into the vapor deposition furnace through the air flow, thus affecting the quality of pyrolytic boron nitride products

The other raw material gas NH3 is alkaline, has a strong irritant, and is also corrosive to pipelines

At the same time, the above two kinds of raw material gases have a certain degree of health hazards when inhaled by the human body, and they are not allowed to be discharged directly into the atmosphere.

[0006]In addition, during the use of raw material gas, there will be occasional problems such as insufficient gas cylinder pressure, failure to release gas, or leakage, etc., which is prone to insufficient raw materials

Moreover, due to the extremely high reaction temperature of the furnace body, most of the equipment in the furnace is made of graphite, so it is easy to cause the gas with oxidizing function to enter the furnace during the replacement of the gas cylinder, thus affecting the quality of pyrolytic boron nitride products in the furnace. quality

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