Ultrapure phosphine analysis method and apparatus thereof

Abstract

The invention relates to an ultrapure phosphine analysis method and an apparatus thereof. The method comprises the following steps: 1, sampling: displacing ultrapure phosphine to a quantitative tube at a flow of 60-120mL / min under 0.05-0.15MPa in an isobaric sample introduction mode with high-flow blow displacement sampling, and ensuring the rapid detection of the impurity concentration change, and giving a balanced analysis value within a very short time; trace impurity separation: sending the above sampled sample gas for detection to a separating system at a flow of 20-50mL / min for the trace impurity separation; and 3, detection: inputting the separated trace impurities to a detector in order to obtain an analysis result. A corrosion and adsorption inhibition treatment highly-airtight pipeline system and a high-flow displacement blow, isobaric sample introduction and three-valve-three-column cutting reverse blow air passage system are used to separate the trace impurities in the ultrapure phosphine, and the direct current discharge helium ionization detector is used to analyze the impurity gas. The balanced analysis value can be given within a very short time, and is quantitative and accurate.

Description

technical field [0001] The invention relates to an analysis method of ultra-pure phosphine and a device thereof. Background technique [0002] Phosphine is used as an indispensable gas in the processes of vapor deposition, epitaxy, diffusion and ion implantation in the semiconductor manufacturing process. The preparation of compound semiconductors GaP and InP also requires phosphine as a "source" material. For example, the phosphosilicate glass purification film grown with phosphine has adsorption characteristics for the impurities in the silicon wafer and plays a terminal protection role; the doped polysilicon grown with phosphine and silane is used as a solar cell and a diffusion source; arsenic doped with phosphorus Light-emitting diodes made of gallium chloride can be used as sensitive components for low temperature testing; in addition, phosphine is also used as standard gas, calibration gas and standard mixed gas; the mixed gas of phosphine and carbon dioxide can be u...

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Problems solved by technology

The disadvantages of the above method are: 1) The double detectors and double Louis gas lead to the unfavorable factors of complex analysis scheme, large dead volume and long analysis cycle, which are no longer suitable for trace analysis of high-purity electronic gases and the development trend of modern chromatography; 2 ) hydrogen flame ionization detector (FID) in the analysis of CO, CO 2 It is necessary to convert to methane before detection, because there are problems with conversion rate and conversion mechanism, which will bring secondary errors; 3) The complex gas path cannot realize full analysis of one injection, prolong the analysis period and reduce the analysis efficiency; 4) In the It is not suitable to use Porapak QS packed column for the analysis of trace arsine in phosphine, as trace arsine is easy to be irreversibly adsorbed, it can be quantitatively analyzed by capillary column or other analytical instruments

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