阅读说明：本技术 一种高纯二碘硅烷的制备方法 (Preparation method of high-purity diiodosilane ) 是由 马建修 王维佳 李广新 靖宇 于 2019-06-20 设计创作，主要内容包括：本发明提出一种高纯二碘硅烷的制备方法,涉及无机化合物制备领域。上述高纯二碘硅烷的制备方法包括以下步骤：在惰性气体保护下,以溶剂醚类作为溶剂,将四氢铝锂和苯基二氯硅烷反应,制得苯硅烷混合物；将苯硅烷混合物加热,蒸出苯硅烷,并将苯硅烷收集；控制反应温度为-80~30℃,搅拌条件下,在粉末状的碘单质中逐滴滴加收集的苯硅烷,同时加入含氧有机化合物作为催化剂,反应后制得二碘硅烷混合物；升高二碘硅烷混合物的温度蒸馏粗二碘硅烷。本发明提出的高纯二碘硅烷的制备方法,初始原料采用无毒性的材料苯基二氯硅烷,该材料与传统的初始原料剧毒化学品苯基三氯硅烷相比,极大的提高了工艺的安全性。(The invention provides a preparation method of high-purity diiodosilane, which relates to the field of inorganic compound preparation and comprises the following steps of reacting lithium aluminum hydride with phenyl dichlorosilane to prepare a phenylsilane mixture under the protection of inert gas and by using solvent ethers as a solvent, heating the phenylsilane mixture to evaporate the phenylsilane, collecting the phenylsilane, controlling the reaction temperature to be-80 ~ 30 ℃, dropwise adding the collected phenylsilane into powdery iodine simple substances under the condition of stirring, simultaneously adding an oxygen-containing organic compound as a catalyst, reacting to prepare a diiodosilane mixture, and raising the temperature of the diiodosilane mixture to distill crude diiodosilane.)

1. The preparation method of the high-purity diiodosilane is characterized by comprising the following steps of:

s1, cleaning and drying a container and a pipeline involved in the process, and purging with inert gas, wherein under the protection of the inert gas, solvent ethers are used as a solvent, the reaction temperature is controlled to be 0 ~ 25 ℃ under the stirring condition, lithium aluminum hydride is added into the solvent ethers, and then phenyldichlorosilane is dropwise added, and the mixture is stirred for 2 ~ 4 hours after the phenyldichlorosilane is dropwise added, so that a phenylsilane mixture is prepared;

s2, heating the phenylsilane mixture, evaporating solvent ethers at 30 ~ 100 ℃, continuously raising the temperature to 120 ~ 180 ℃, evaporating phenylsilane, and collecting the phenylsilane;

s3, controlling the reaction temperature to be-80 ~ 30 ℃, dropwise adding the phenyl silane collected in the S2 step into a powdery iodine simple substance under the stirring condition, simultaneously adding an oxygen-containing organic compound as a catalyst, heating to room temperature after dropwise addition, and reacting for 4 ~ 8 hours to obtain a diiodosilane mixture;

and S4, increasing the temperature of the diiodosilane mixture, collecting the byproduct benzene and light component impurities at the temperature of 60 ~ ℃, continuously increasing the temperature, and distilling the crude diiodosilane at the temperature of 140 ~ ℃.

2. The method for preparing high purity diiodosilane according to claim 1, further comprising a step S5 after the step S4: and purifying the crude diiodosilane to obtain refined diiodosilane.

3. The method of claim 2, wherein the purification temperature in the step of S5 is 120 ~ 140 ℃.

4. The method of claim 1, wherein the solvent ethers, the lithium aluminum hydride and the phenyl dichlorosilane are used in a ratio of (240 ~ 252) ml to (15 ~ 20.4.4) g to 115ml in the step of S1.

5. The method according to claim 1, wherein in the step of S1, the solvent ether is diethyl ether or ethyl sulfide.

6. The method of claim 1, wherein in the step of S3, the ratio of the iodine, the phenylsilane, and the oxygen-containing organic compound is (51 ~ 55) g (25 ~ 29) ml to 1 ml.

7. The method of claim 6, wherein in the step S3, the iodine powder has a particle size of 50 ~ 1000 μm and is ground under an inert gas atmosphere.

8. The method of claim 7, wherein the inert gas used for milling the iodine is one of high purity nitrogen, helium, neon, argon or xenon in step S3.

9. The method according to claim 6, wherein the oxygen-containing organic compound is one of an ester, a ketone, and an ether.

10. The method of claim 9, wherein the oxygen-containing organic compound is one of ethyl acetate, ethyl formate, acetone, and diethyl ether.

Technical Field

The invention relates to the field of inorganic compound preparation, and in particular relates to a preparation method of high-purity diiodosilane.

Background

Diiodosilane (DIS) is used as a silicon source for chemical vapor deposition, can generate more active silicon free radicals under the enhancement of plasma, and has the characteristics of lower temperature and more controllable pressure operation on the premise of keeping high deposition rate. At present, with the trend of ultra-miniaturization of semiconductor devices (especially chips), the limitation of moore's law is broken through, and the substrate structure of the conventional semiconductor is often required to be improved, and DIS as a silicon precursor can be adaptively vapor-deposited on a plurality of substrates, such as GaAs, BN, crystalline silicon, polycrystalline silicon, amorphous silicon, epitaxial fragmented silicon layers, SiO2, SiC, SiOC, SiN, SiCN, organosilicone glass (OSG), organosilicone silicate glass (OFSG), fluorosilicone glass (FSG), metal layers (Cu, Al, etc.), organic high polymer substrates, and the like. The diiodosilane has unique advantages and wide market prospect.

At present, the mature method for synthesizing diiodosilane mainly comprises the following steps of reacting phenylsilane with iodine simple substance at the temperature of minus 20 ℃ to generate diiodosilane and benzene, wherein the specific reaction formula is as follows:

Ph-SiH₃ + I₂→Ph-H + SiH₂I₂（1）

however, purchasing phenylsilane has several problems: 1. the price of the phenylsilane is high, and at present, the phenylsilane mainly depends on import, and almost no manufacturers exist in China. 2. The phenylsilane is dangerous, can explode when meeting water, is easy to absorb moisture, is difficult to store and is easy to deteriorate; 3. the phenylsilane can generate silane, and the generation of diiodosilane is inhibited. Therefore, the preparation of diiodosilane requires the synthesis of raw material phenylsilane, and the current method for synthesizing phenylsilane is mainly prepared by reducing phenyltrichlorosilane with lithium aluminum hydride, and the reaction equation is as follows:

Ph-SiCl₃+LiAlH₄→4Ph-SiH₃+3LiCl+3AlCl₃（2）

according to the formula (2), phenyl trichlorosilane is a highly toxic chemical, the product phenylsilane reacts with water and humid air to emit easily spontaneous combustion gas, the operation is difficult, the reaction kinetics is slow, and Ph-SiCl is easily generated₂H、Ph-SiClH₂And the above reactions are laboratory grade, and large-scale systematic production of diiodosilane is not realized. How to obtain diiodosilane efficiently and safely and simultaneously realize the purification technology of diiodosilane is not reported.

Disclosure of Invention

In order to overcome the defects and shortcomings of the prior art, the invention aims to provide a preparation method of high-purity diiodosilane, which creatively adopts phenyldichlorosilane and lithium aluminum hydride to prepare phenylsilane so as to prepare diiodosilane, so that the unsafety of the traditional process for preparing phenylsilane by adopting a highly toxic chemical phenyltrichlorosilane is improved, meanwhile, the reaction kinetics of phenyldichlorosilane is high, few byproducts are generated, and the reaction conversion rate is improved. The preparation method has the characteristics of high efficiency, high safety, high purity and easiness in large-scale production.

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

The invention provides a preparation method of high-purity diiodosilane, which comprises the following steps:

s1, cleaning and drying a container and a pipeline involved in the process, purging with inert gas, under the protection of the inert gas, taking solvent ether as a solvent, controlling the reaction temperature to be 0 ~ 25 ℃ under the stirring condition, adding lithium aluminum hydride into the solvent ether, then dropwise adding phenyl dichlorosilane, and stirring for 2 ~ 4h after the dropwise adding of the phenyl dichlorosilane is finished to prepare a phenyl silane mixture;

s2, heating the phenylsilane mixture, evaporating solvent ethers at 30 ~ 100 ℃, continuously raising the temperature to 120 ~ 180 ℃, evaporating phenylsilane at 120, and collecting the phenylsilane;

s3, controlling the reaction temperature to be-80 ~ 30 ℃, dropwise adding the phenylsilane collected in the S2 step into the powdery iodine simple substance under the stirring condition, simultaneously adding an oxygen-containing organic compound as a catalyst, heating to room temperature after the dropwise addition is finished, and reacting for 4 ~ 8 hours to obtain a diiodosilane mixture;

and S4, increasing the temperature of the diiodosilane mixture, collecting the byproduct benzene and light component impurities at the temperature of 60 ~ ℃, continuously increasing the temperature, and distilling the crude diiodosilane at the temperature of 140 ~ ℃.

Preferably, the step of S4 is followed by the step of S5: and purifying the crude diiodosilane to obtain refined diiodosilane.

Preferably, the temperature of purification is 120 ~ 140 ℃.

Preferably, the solvent ethers, lithium aluminum hydride and phenyldichlorosilane are used in a ratio of (240 ~ 252) ml, (15 ~ 20.4.4) g: 115 ml.

Preferably, the solvent ether is diethyl ether or ethyl sulfide.

Preferably, the using ratio of the iodine simple substance, the phenylsilane and the oxygen-containing organic compound is (51 ~ 55) g, (25 ~ 29) ml to 1 ml.

Preferably, the particle size of the powdery elementary iodine is 50 ~ 1000 μm, and the powdery elementary iodine is obtained by grinding under an inert gas atmosphere.

Preferably, the inert gas used for grinding the iodine simple substance is one of high-purity nitrogen, helium, neon, argon or xenon.

Preferably, the oxygen-containing organic compound is one of esters, ketones or ethers.

Preferably, the oxygen-containing organic compound is one of ethyl acetate, ethyl formate, acetone and diethyl ether.

The preparation method of the high-purity diiodosilane has the beneficial effects that:

(1) the initial raw material of the preparation method adopts the nontoxic material phenyldichlorosilane, and compared with the traditional initial raw material of the highly toxic chemical phenyltrichlorosilane, the material greatly improves the safety of the process. Meanwhile, the reaction kinetics of the phenyldichlorosilane is high, few byproducts are generated, the conversion rate of reactants can be effectively improved, and the diiodosilane with the purity of over 99.8 percent is obtained through purification.

(2) In the reaction for preparing diiodosilane, reactants and products are easy to react with moist air and water, and the invention ensures the chemical stability of the phenyl silane and the diiodosilane in the whole reaction process through the protection of inert gas.

(3) The preparation method disclosed by the invention is strong in operation controllability, high in product stability, high in safety, easy for large-scale production and applicable to large-scale production of diiodosilane.

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.

Phenyldichlorosilane, an irritant, clear, colorless, flammable liquid with a boiling point of 184 ℃, a relative density (water = 1) of 1.204g/cm3, is non-toxic and reacts violently with water.

Phenylsilane, also known as phenylsilane, is a chemical with the molecular formula of C₆H₈Si, transparent colorless flammable liquid, boiling point 120 deg.C, melting point-68 deg.C, flash point 8 deg.C, relative density (water = 1) 0.8681g/cm³It is non-toxic and reacts violently when meeting water.

The embodiment of the invention provides a preparation method of high-purity diiodosilane, which comprises the following steps:

s1, cleaning and drying containers and pipelines involved in the process, purging with inert gas, taking solvent ethers as a solvent under the protection of the inert gas, controlling the reaction temperature to be 0 ~ 25 ℃ under the stirring condition, adding lithium aluminum hydride into the solvent ethers, then dropwise adding phenyl dichlorosilane, stirring for 2 ~ 4h after the dropwise adding of the phenyl dichlorosilane is finished, and preparing a phenyl silane mixture, wherein in the reaction for preparing diiodosilane, reactants and products are easy to react with humid air and water.

Furthermore, in the preferred embodiment of the invention, the dosage ratio of the solvent ethers, the lithium aluminum hydride and the phenyl dichlorosilane is (240 ~ 252) ml, (15 ~ 20.4.4) g: 115ml, the dosage ratio is less in the impurity of the synthesized phenyl silane and higher in the conversion rate, and the phenyl dichlorosilane is used as a safe and nontoxic raw material, so that the whole reaction is safer and more reliable.

Further, in a preferred embodiment of the present invention, the solvent ether is diethyl ether or diethyl sulfide. The ether solvent can better dissolve the lithium aluminum hydride and can be mutually soluble with the phenyl dichlorosilane. Especially, diethyl ether and ethyl sulfide, and lithium aluminum hydride have better solubility in the two.

S2, heating the phenylsilane mixture, evaporating solvent ethers at 30 ~ 100 ℃, continuously raising the temperature to 120 ~ 180 ℃, evaporating phenylsilane at 120, and collecting the phenylsilane;

s3, controlling the reaction temperature to be-80 ~ 30 ℃, dropwise adding the phenylsilane collected in the S2 step into the powdery iodine simple substance under the stirring condition, simultaneously adding an oxygen-containing organic compound as a catalyst, heating to room temperature after the dropwise addition is finished, and reacting for 4 ~ 8 hours to obtain a diiodosilane mixture;

furthermore, in the preferred embodiment of the invention, the dosage ratio of the iodine simple substance, the phenylsilane and the oxygen-containing organic compound is (51 ~ 55) g, (25 ~ 29) ml: 1ml, in the traditional preparation process, the reaction of the iodine simple substance and the phenylsilane to generate the diiodosilane and the benzene is adopted to prepare the diiodosilane, and in the embodiment, the oxygen-containing organic compound is introduced as the catalyst, so that the reaction rate can be accelerated, and the conversion rate can be improved.

Furthermore, in the preferred embodiment of the invention, the particle size of the powdery iodine simple substance is 50 ~ 1000 μm, and the iodine simple substance is prepared by grinding in the inert gas atmosphere.

Further, in a preferred embodiment of the present invention, the inert gas used for grinding the iodine is one of high purity nitrogen, helium, neon, argon or xenon. The iodine elementary substance is ground under the protection of the inert gas, so that the chemical stability of the iodine elementary substance is kept.

Further, in a preferred embodiment of the present invention, the oxygen-containing organic compound is one of an ester, a ketone, or an ether.

Further, in a preferred embodiment of the present invention, the oxygen-containing organic compound is one of ethyl acetate, ethyl formate, acetone and diethyl ether. When the substances are used as catalysts, the catalytic effect is good.

And S4, increasing the temperature of the diiodosilane mixture, collecting the byproduct benzene and light component impurities at the temperature of 60 ~ ℃, continuously increasing the temperature, and distilling the crude diiodosilane at the temperature of 140 ~ ℃.

Further, in the preferred embodiment of the present invention, the step S4 is followed by the step S5: and purifying the crude diiodosilane to obtain refined diiodosilane. The purity of the diiodosilane can be further improved by purification.

Further, in the preferred embodiment of the present invention, the purification temperature is 120 ~ 140 ℃.

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