High-purity trimethylaluminum and purification method of crude trimethylaluminum

Abstract

High-purity trimethylaluminum has the following impurity contents: organosilicon components<=0.5 ppm, chlorine components<=20 ppm, hydrocarbon components<=1,000 ppm, Ca<=0.05 ppm, Fe<=0.05 ppm, Mg<=0.05 ppm, Na<=0.05 ppm, Si (Si components other than the organosilicon components)<=0.07 ppm, Zn<=0.05 ppm, and S<=0.05 ppm. The high-purity trimethylaluminum can be obtained by removing impurities from crude trimethylaluminum through distillation and evaporation.

Description

technical field [0001] The invention relates to a method for refining high-purity trimethylaluminum and crude trimethylaluminum. Background technique [0002] Compound semiconductor materials are used in the electronics industry, such as in microwave oscillators, semiconductor light-emitting diodes, lasers and infrared detectors. The quality of compound semiconductor materials obtained by epitaxial growth of organometallic compounds is mainly controlled by impurities, especially those impurities in the raw materials of organometallic compounds. Therefore, high-purity organometallic compounds are required in order to prepare compound semiconductor materials with high functions. [0003] Impurities in organometallic compounds, especially trimethylaluminum, include hydrocarbon components, organosilicon components, alkylaluminum oxides, metal compounds, and the like. Among these impurities, organosilicon components and alkylaluminum oxides generally have a vapor pressure highe...

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Problems solved by technology

[0015] However, adduct refining methods have many disadvantages because these methods need to add solvents and chemicals to the trimethylaluminum that needs to be purified, and it needs to be made into high-purity solvents and chemicals before adding them , and the recovery rate of trimethylaluminum is low, solvents and chemicals need to be disposed of after use, the chemicals are expensive, and the operation is heavy

[0016] Distillation methods involving contact with metallic sodium or metallic potassium can separate organosilicon components to some extent, but for compound semiconductors, the removal rate of organosilicon components is not sufficient, especially for materials that require high purity. application

[0017] Methods involving cooling and solidification of organometallic compounds are also problematic. The removal rate of organosilicon components or alkylaluminum oxides from trimethylaluminum is not only unstable but also insufficient to obtain satisfactory results. Industrial production requires Complicated facilities and require heavy handling

[0018] A method involving the mixing of an organometallic compound containing one or more halogen atoms and / or hydrogen atoms with an alkali metal halide, followed by heat treatment to remove the alkylaluminum oxide is also problematic, the effect of this method is limited to the alkylaluminum oxide , besides their removal effect is not good enough

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