GB/T 24579-2009
Test methods for measuring surface metal contamination of polycrystalline silicon by acid extraction-atomic absorption spectroscopy (English Version)

Standard No.

GB/T 24579-2009

Language

Chinese, Available in English version

Release Date

2009

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Latest

GB/T 24579-2009

Scope

1.1 This standard specifies the analysis method for leaching metal impurities from the surface of polycrystalline silicon block with acid, and quantitatively detecting trace metal impurities on the surface of polycrystalline silicon block by graphite furnace atomic absorption. 1.2 This standard applies to the detection of alkali metals, alkaline earth metals and the first series of transition elements such as sodium, aluminum, iron, chromium, nickel and zinc. 1.3 This standard is applicable to the detection of metal pollutants on the surface of various rods, blocks, grains, and sheet-shaped polycrystalline or monocrystalline silicon. Due to the irregular shape of blocks, flakes or granules, it is difficult to accurately measure the area, and the result is calculated according to the weight of the sample. The sample weight used was 50 g to 300 g, and the detection limit was 0.01 ng/g. 1.4 The strength, composition, temperature and leaching time of the acid determine the depth of surface corrosion and the leaching efficiency of surface pollutants. Less than 1% of the sample weight is etched away in this test method. 1.5 This test method proposes a specific sample size, acid composition, corrosion cycle, test environment and instrument scheme. These parameters can be adjusted, but may affect the recovery efficiency and retention of metals. This method is suitable for the determination of samples with a weight of 25 g to 5 000 g. For the purpose of arbitration, this test method stipulates that the sample weight is 300 g. The test method is specified in terms of interference and bias in the results. 1.6 This test method specifies the use of graphite furnace atomic absorption spectrometry for the analysis of acid-extracted trace metal content. Other instruments of comparable sensitivity such as inductively coupled plasma/mass spectrometers may also be used. 1.7 The detection limit and bias of the method depend on the efficiency of the acid extraction process, sample size, method interferences, absorption spectra of each element and instrument sensitivity, background and blank values. 1.8 This method is to use hot acid to etch away the silicon surface, the etchant is harmful, the operation must be carried out in a fume hood, and the whole process must be very careful. Hydrofluoric acid solutions are very dangerous and should not be used by persons not familiar with special precautions.

GB/T 24579-2009 Referenced Document

• GB/T 11446.1-1997 Electronic grade water
• ISO 14644-1 Cleanrooms and associated controlled environments - Part 1: Classification of air cleanliness by particle concentration (includes Redline Version)*， 2015-02-01 Update

GB/T 24579-2009 history

• 2009 GB/T 24579-2009 Test methods for measuring surface metal contamination of polycrystalline silicon by acid extraction-atomic absorption spectroscopy