Polycrystalline silicon surface metal detection sample preparation method and detection method

A surface metal and detection sample technology, which is applied in the preparation of polysilicon surface metal detection samples and in the field of polysilicon surface metal detection, can solve the problems of inability to accurately reflect the metal impurity content on the surface of polysilicon products, increase the difficulty of operation, and long detection cycle, etc., to shorten the preparation time, improve detection accuracy, and fast sample preparation

Pending Publication Date: 2022-01-07
新疆新特新能材料检测中心有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In the process of preparing the test sample, due to the leaching method, it takes a long time to prepare the test sample, and the long-term exposure of the leaching solution to the environment will cause K, Ca, Al, Fe and other impurities in the environment to settle to the In the leaching solution, the detection results cannot accurately reflect the surface metal impurity content of polysilicon products and the detection period is long; in addition, due to the low acidity of the mixed solution (the volume ratio of nitric acid, hydrofluoric acid, hydrogen peroxide and water is 1:1:1:50), so it can only be leached, and even needs to be heated during leaching to make the metal impurities on the surface of the polysilicon react with the mixed solution and deposit into the leaching solution. Increased operational difficulty

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  • Polycrystalline silicon surface metal detection sample preparation method and detection method
  • Polycrystalline silicon surface metal detection sample preparation method and detection method

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preparation example Construction

[0029] In view of the existing technology, the leaching time in the preparation process of the metal detection sample on the polysilicon surface is long, and impurities such as K, Ca, Al, Fe are easily introduced from the introduced environment, resulting in long detection cycle and low detection accuracy. Therefore, the present invention discloses a method for preparing a polysilicon surface metal detection sample, comprising:

[0030] S101 sampling: weighing polysilicon;

[0031] S102 pickling: using a mixed acid solution of nitric acid and hydrofluoric acid to quickly rinse the surface of the polysilicon to obtain a pickling solution;

[0032] S103 Washing with water: washing the pickled polysilicon with water to obtain a washing solution;

[0033] S104 Evaporation: heating the pickling liquid and water washing liquid together to evaporate to dryness;

[0034] S105 Constant volume: adding nitric acid to the evaporated residue to dissolve, and then constant volume of the d...

Embodiment 1

[0039] Such as figure 1 As shown, this embodiment discloses a method for preparing a polysilicon surface metal detection sample, including:

[0040] S101 Sampling: weighing polysilicon.

[0041] Among them, considering that too much polysilicon will increase the amount of acid solution and water required for subsequent pickling and water washing, prolong the time required for subsequent evaporation and other processes, and reduce the sample preparation speed, too little polysilicon will increase the difficulty of operation , increasing the operating error. Therefore, after a large number of tests, the amount of polysilicon in this embodiment is preferably 30-50 g, and since the content of metal on the surface of polysilicon is at the ppbw level, the mass of polysilicon weighed should be accurate to 0.0001 g.

[0042] S102 pickling: using a mixture of nitric acid and hydrofluoric acid to quickly rinse the surface of the polysilicon to obtain a pickling solution.

[0043] Amo...

preparation example 1

[0059] This preparation example discloses a method for preparing a polysilicon surface metal detection sample, including:

[0060] (1) Weigh 30.0000 g of polysilicon, and put it into a polytetrafluoroethylene beaker.

[0061] (2) Place the above-mentioned beaker filled with polysilicon in a fume hood with a cleanliness level of ten; use a nitric acid solution with a mass fraction of 55% and a hydrofluoric acid solution with a mass fraction of 38% in a volume ratio of 2:1. The resulting mixed acid solution; use a pipette to take 10ml of the above mixed acid solution, and quickly pour it onto the polysilicon surface at a rate of 2 to 3 drops / second (the amount of each drop is controlled at about 0.2ml) (i.e. acid rinsing). The metal impurities on the polysilicon surface are rapidly dissolved to obtain a pickling solution containing metal impurities.

[0062] (3) Slowly pour 5ml of deionized water onto the surface of the polysilicon after rinsing with the mixed acid solution (ie...

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Abstract

The invention discloses a preparation method of a polycrystalline silicon surface metal detection sample. The preparation method comprises the following steps: weighing polycrystalline silicon; quickly leaching the surface of the polycrystalline silicon by using a mixed acid solution of nitric acid and hydrofluoric acid to obtain a pickling solution; carrying out water leaching on the polycrystalline silicon subjected to acid pickling to obtain a water washing solution; heating the pickling solution and the water washing solution together to be dried by distillation; and adding nitric acid into the dried residues for dissolving, and fixing the volume of a solution obtained by dissolving to obtain a sample for detecting the metal on the surface of the polycrystalline silicon. The invention also discloses a polycrystalline silicon surface metal detection method comprising the sample preparation method. The preparation time and the detection period of the detection sample can be greatly shortened, and the detection accuracy is improved.

Description

technical field [0001] The invention belongs to the technical field of polysilicon, and in particular relates to a method for preparing a polysilicon surface metal detection sample and a polysilicon surface metal detection method. Background technique [0002] Polysilicon is the main raw material for manufacturing high-purity silicon products such as silicon polished wafers, solar cells, and electronic chips, and its purity requirements are very high, especially for electronic-grade polysilicon, which requires a purity of more than 99.9999%. The impurities in polysilicon are divided into surface metal impurities and matrix metal impurities according to their source and distribution. The matrix metal impurities come from materials such as raw silicon powder for the production of polysilicon products, which can be basically removed by rectification, and the content of B and P can be reduced to the order of ppta. Surface metal impurities come from the external environment. For...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N1/28G01N1/32G01N21/73G01N27/626
CPCG01N1/28G01N1/32G01N21/73G01N27/626
Inventor 赵晶晶陈星武江覃益东王凡平
Owner 新疆新特新能材料检测中心有限公司
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