Process for preparing high-purity hexachlorodisilane

Abstract

The invention relates to the field of preparation of high-purity hexachlorodisilane, in particular to a process for preparing high-purity hexachlorodisilane. According to the method, sorbitol is adopted to replace chelate resin to adsorb metal impurities, nitrogen is added in the purification process for accompanying as inert gas for protection and rectification, the introduced nitrogen mainly hasthe effects of reducing the distillation temperature and enhancing stirring of liquid in the tower kettle to prevent local overheating of the liquid in the kettle, therefore hexachlorodisilane is prevented from being heated to deteriorate. The process is high in rectification efficiency and low in process cost.

Description

[0001] The invention relates to the field of preparation of high-purity hexachlorodisilane, in particular to a process for preparing high-purity hexachlorodisilane. Background technique [0002] Hexachlorodisilane (HCDS) high-purity silicon-based semiconductor material is the key raw material for high-end chip design, wafer manufacturing, memory and logic chip design, and the "blood" of large-scale integrated circuits. The localization process of very large-scale integrated circuits will inevitably require the localization of key raw materials and high-end raw materials, and high-purity HCDS plays a vital role in key semiconductor film structures. High-purity HCDS is a key raw material in the preparation of silicon nitride and high-end silicon oxide thin film materials, and is widely used in the preparation of thin film intermediate dielectric layers, layers around polysilicon interconnect lines, and gate transistor spacers. The purity of the product is required to be above 6N...

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Problems solved by technology

[0003] CN103011173A discloses a method for synthesizing hexachlorodisilane, which is characterized in that it includes the following process steps: (1) Add silicon powder and catalyst into the reaction kettle, add silicon tetrachloride under the protection of inert gas, and heat up to 30-200 ℃ for 3-24 hours, cooled to room temperature to obtain a reaction mixture; the molar ratio of silicon powder to silicon tetrachloride is 1:100-1000; (2) under the protection of inert gas, the reaction obtained in step (1) The mixture is filtered, the filtrate is distilled, and the distilled components at 145-147°C are collected, which is the hexachlorodisilane. This method mainly introduces a synthesis method of hexachlorodisilane, and the obtained hexachlorodisilane cannot meet the semiconductor requirements. production demand

[0004] CN108017060A discloses a method for purifying hexachlorodisilane, which is characterized in that it includes the following steps: passing industrial-grade hexachlorodisilane into an exchange column equipped with an adsorption resin, at a temperature of 50-65°C and a flow rate of 0.2-2BV Adsorption and purification are carried out under the condition of / h, and the product is the purified hexachlorodisilane product. The chelating resin used in this method is mainly composed of cyclooctyl tetraene tricarbonyl iron, hydroxybutyl vinyl ether, 1,1 - Bis(trimethylsilyl chloride)ethylene, 8-allyloxy-quinoline, 3,3-dimethyl-1-butynyl cuprous, ammonium persulfate, dodecylbenzenesulfonic acid, etc., The composition of the resin is complex, the required cost is high, and the process control parameters are strict

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