Silicon briquette washing method and application

A silicon block and cleaning device technology, applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve problems such as inability to guarantee etching uniformity, large fluctuations in surface metal impurities, and increased product backwashing volume. Achieve the effect of optimizing the silicon block cleaning process, alleviating uneven pickling, improving pickling efficiency and product quality

Active Publication Date: 2018-12-07
青海黄河上游水电开发有限责任公司新能源分公司 +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] However, there are still blind spots in the cleaning method in the prior art, and the uniformity of etching cannot be guaranteed, resulting in acid spots and color differences on the silicon block, and large fluctuations in the content of metal impurities on the surface, which increases the amount of backwashing of the product

Method used

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  • Silicon briquette washing method and application
  • Silicon briquette washing method and application
  • Silicon briquette washing method and application

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0113] A method for cleaning a silicon block, comprising the steps of:

[0114] 1. Pickling

[0115] The silicon blocks were pickled three times. Figure 5 A plan view of the acid pool for silicon block cleaning, placing the silicon blocks in sequence Figure 5 Nitric acid in TK-40002A: hydrofluoric acid = 10:1 acid solution pool, nitric acid in TK-40002B: hydrofluoric acid = 15:1 acid solution pool, nitric acid in TK-40002C: hydrogen Hydrofluoric acid = 30:1 acid pool.

[0116] The pickling liquid used for the first pickling is nitric acid:hydrofluoric acid=10:1v / v, the temperature is 33°C, and the time is 5min.

[0117] The pickling liquid used for the second pickling is nitric acid:hydrofluoric acid=15:1v / v, the temperature is 36°C, and the time is 5min.

[0118] The pickling liquid used for the third pickling is nitric acid:hydrofluoric acid=30:1v / v, the temperature is 31°C, and the time is 5min.

[0119] Wherein, nitric acid is an aqueous solution of nitric acid with...

Embodiment 2-9

[0130] In the silicon block cleaning method in embodiment 2-embodiment 9, the proportion of nitric acid and hydrofluoric acid and the mass fraction of nitric acid and hydrofluoric acid in pickling are shown in Table 1, and the rest of the steps are the same as in embodiment 1.

[0131] Table 1 The proportioning ratio of nitric acid and hydrofluoric acid, the mass fraction of nitric acid and hydrofluoric acid

[0132]

[0133]

Embodiment 10

[0135] A method for cleaning a silicon block, comprising the steps of:

[0136] 1. Pickling

[0137] The silicon block is laid in the cleaning device described in CN205264678U, and then pickled three times.

[0138] The pickling liquid used for the first pickling is nitric acid:hydrofluoric acid=10:1v / v, the temperature is 32°C, and the time is 6min.

[0139] The pickling liquid used for the second pickling is nitric acid:hydrofluoric acid=15:1v / v, the temperature is 35°C, and the time is 4min.

[0140] The pickling liquid used for the third pickling is nitric acid:hydrofluoric acid=30:1v / v, the temperature is 33°C, and the time is 6min.

[0141]Wherein, nitric acid is an aqueous solution of nitric acid with a mass fraction of 70%; hydrofluoric acid is an aqueous solution of hydrofluoric acid with a mass fraction of 49%.

[0142] 2. Rinse

[0143] Use ultrapure water for overflow rinsing.

[0144] 3. Soak

[0145] (1) Cold soaking

[0146] Soak at 22°C for 5h.

[0147]...

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Abstract

The invention discloses a silicon briquette washing method and application, and belongs to the technical field of silicon briquette washing. The method comprises the steps of sequentially pickling, rinsing, cold soaking and hot soaking, wherein the pickling solution used in pickling is prepared from nitric acid and hydrofluoric acid; the pickling step is performed in three acid solutions having the nitric acid proportion increased in a gradient way, and the acid solution used in first pickling contains nitric acid and hydrofluoric acid in a ratio of (9-11):1v/v. According to the method, the silicon briquette is pickled by sequentially using three acid solutions having the nitric acid proportion increased in a gradient way, the silicon briquette washing process is optimized, the silicon pickling efficiency and product quality can be improved, and the technical problems of non-uniform pickling, acid spotting and chromatic aberration, high content of metal impurities and large content fluctuation of metal impurities caused by washing a single-proportion pickling tank can be relieved.

Description

technical field [0001] The invention belongs to the technical field of silicon block cleaning, and in particular relates to a silicon block cleaning method and application. Background technique [0002] As a part of the final production process of electronic-grade polysilicon, which is a semiconductor raw material, cleaning electronic-grade polysilicon is of great significance to the assurance of product quality and the treatment of surface metal impurities. [0003] Electronic-grade polysilicon block cleaning process is to put the broken electronic-grade silicon block into the silicon block cleaning device, put it in the pickling equipment for pickling, etch the surface of the silicon block with acid solution to remove the surface pollution of the silicon material, so that The metal impurities on the surface of the silicon block meet the quality requirements of the surface metal of electronic grade polysilicon. [0004] However, the cleaning method in the prior art still h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/037
CPCC01B33/037
Inventor 秦榕曹文海李永红张永辉张永良刘虎孟海生安生虎刘生章高鹏危胜
Owner 青海黄河上游水电开发有限责任公司新能源分公司
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