Preparation method of high-purity diiodosilane

Abstract

The invention provides a preparation method of high-purity diiodosilane, and relates to the field of preparation of inorganic compounds. The preparation method of the high-purity diiodosilane comprises the following steps: under the protection of inert gas, with ethers as a solvent, performing a reaction on lithium aluminum hydride with phenyl dichlorosilane to prepare a phenylsilane mixture; heating the phenylsilane mixture for evaporating out phenylsilane, and collecting the phenylsilane; by controlling the reaction temperature to be -80 DEG C to 30 DEG C, dropwise adding the collected phenylsilane into the powdery iodine elementary substance under the stirring condition, meanwhile, adding an oxygen-containing organic compound as a catalyst, and performing a reaction to obtain a diiodosilane mixture; raising the temperature of the diiodosilane mixture to distill the crude diiodosilane. According to the preparation method of the high-purity diiodosilane provided by the invention, theinitial raw material is the non-toxic material phenyl dichlorosilane, and compared with the traditional highly toxic chemical phenyl trichlorosilane as the initial raw material, the safety of the process is greatly improved.

Description

technical field [0001] The invention relates to the field of preparation of inorganic compounds, and in particular to a preparation method of high-purity diiodosilane. Background technique [0002] Diiodosilane (DIS), as a silicon source for chemical vapor deposition, can generate more active silicon radicals under plasma enhancement. Under the premise of maintaining a high deposition rate, the reaction chamber has the characteristics of lower temperature and more controllable pressure operation. At present, with the ultra-miniaturization trend of semiconductor devices (especially chips), it is often necessary to improve the substrate structure of traditional semiconductors to break through the limitations of Moore's Law. As a silicon precursor, DIS can be adaptively vaporized on many substrates. Deposition, such as GaAs, BN, crystalline silicon, polycrystalline silicon, amorphous silicon, epitaxial fragmented silicon layers, SiO2, SiC, SiOC, SiN, SiCN, organosilicate glass ...

AI Technical Summary

Problems solved by technology

[0005] However, the purchase of phenylsilane has the following problems: 1. The price of phenylsilane is expensive, and currently it mainly relies on imports, and there are almost no domestic manufacturers

2. Phenylsilane is very dangerous, it will explode when exposed to water, it is easy to absorb moisture, it is not easy to store, and it is easy to deteriorate; 3. Phenylsilane will produce silane and inhibit the production of diiodosilane

[0007] Through practice, it is found that in equation (2), phenyltrichlorosilane is a highly toxic chemical, and the product phenylsilane reacts with water and humid air to release flammable gas, which is difficult to operate, and the reaction kinetics is slow, and it is easy to generate Ph-SiCl 2 H, Ph-SiClH 2 and other impurities, the above two-step reaction without nitrogen atmosphere protection is extremely dangerous, and the above reactions are all laboratory-level, and large-scale system production of diiodosilane has not been realized

How to obtain diiodosilane efficiently and safely, while realizing its purification technology has not been reported

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