Method and reaction system for continuously producing disilane

Abstract

The invention discloses a method for assisting in processing silicon powder and metal powder by using thermal plasma under the condition of micro negative pressure so as to promote continuous reaction of the silicon powder and the metal powder to generate metal silicide powder. The invention also relates to a method for preparing disilane by using the metal silicide powder as a raw material to react with strong acid in a specific solvent, and a reaction system for realizing the method. According to the preparation method, silicon powder and metal powder are instantly melted and vaporized in a plasma core area by utilizing the high energy density of hot plasma, and then are rapidly cooled to finish alloying and chemical reaction and form nanoscale metal silicide powder; under the condition of micro-negative pressure, the formed nano-scale metal silicide powder reacts with strong acid in a specific solvent to generate silane series product gas, and the proportion of disilane is obviously higher than that of disilane in the existing production process; meanwhile, the whole technological process is carried out under the micro-negative pressure condition, operation is safe and easy to control, and continuous production can be achieved.

Description

technical field [0001] The invention relates to the production field of disilane, in particular to a method and a reaction system for continuously producing disilane. Background technique [0002] Silane gas is an important raw material in the semiconductor and photovoltaic industries. It is mainly used to deposit various silicon-containing films, especially amorphous silicon and polycrystalline silicon films. At present, the most widely used silane gas is monosilane, but the decomposition temperature of monosilane used to deposit polysilicon thin films is high, and the deposition rate is slow, which restricts the application of polysilicon thin films to a certain extent, such as directly depositing polysilicon on glass substrates film. High-order silane has lower decomposition temperature, faster deposition rate, and the deposited and grown film has a more regular lattice arrangement, which is more conducive to the growth and formation of large-grain polysilicon film. For...

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Problems solved by technology

And because the reaction occurs on the surface of the solid phase, after the reaction generates magnesium silicide, the magnesium silicide occupies the reaction site and will hinder the further occurrence of the reaction, so it is difficult to achieve sufficient reaction inside the powder, so the conversion rate of the alloying reaction is low , and the yield of disilane is low

[0007] In summary, the monosilane cracking method of the prior art needs to be carried out under low pressure, the production efficiency is low, a large amount of silicon powder is produced by-product, and the production capacity is difficult to enlarge; the hexachlorodisilane hydrogenation process is complex and difficult to operate; while the silicon magnesium method The batch operation time of the process sheet is long and the conversion rate is low, resulting in a small overall production capacity

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