Method for the analysis of boron and metalic impurities in pure SiC14-Spectro-chemical method
Some standard content:
Standard of the Ministry of Electronics Industry of the People's Republic of China SJ259485
Chemical Spectroscopic Analysis Method for Boron and Metal Impurities in High-Purity Silicon Tetrachloride
Published on July 31, 1985
Implemented on January 1, 1986
Approved by the Ministry of Electronics Industry of the People's Republic of China Standard of the Ministry of Electronics Industry of the People's Republic of China Chemical Spectroscopic Analysis Method for Boron and Metal Impurities in High-Purity Silicon Tetrachloride
This standard method is suitable for determining the content of boron and metal impurities in high-purity silicon tetrachloride. 1 Principle of the method
SJ 2594-85
The metal impurities in silicon tetrachloride must exist in the form of chlorides. It can form a certain complex with (with). In a closed evaporator, control the appropriate temperature (50℃) to add a cyclic gas to volatilize the nitride tetranitride, separate it from the complex, and decompose the residual silicic acid diselenide with hydrofluoric acid. The dense metal is transformed into liquid, and the transfer is carried out on the stone for spectral measurement. 2 Instruments and equipment
Spectrometer: medium-sized prism spectrometer or 1 meter plane grating spectrometer. Light source: AC arc. ||tt| | Electrode: Diameter mm flat graphite ground electrode,
Microphotometer: Domestic CD type or other wall number: Photosensitive plate: Domestic UV I type or other quantitative spectrum plate, Wanggan pick: Shepherd's purse
Volatilizer: See the figure below
Slow sand bottle concentrated H, SO concentrated [, SO.% EDTA
t Ren Lei threshing machine: ② Stone sieve plate: Graphite pants Bottom of the threshing machine: Electric furnace. Ministry of Electronics Industry of the People's Republic of China 1985-07-31 issued N
1986-01-01 implementation
3 Reagents
SJ2594-85
3.1 Ultrapure water: Use after distillation and purification in a secondary ion exchange water gate quartz evaporator (or industrial distiller). 3.2 Mannitol solution: 0.5% aqueous solution (pure mannitol). 3.3 Polystyrene diester solution: 10mg/ml3.4 Hydrogen fluoride: High-purity hydrofluoric acid and then purified by steaming tank: 3.5 Hydrochloric acid: High-purity hydrochloric acid is purified by equal mixing method or boiling distillation. 3.6 Ethylene: Analytical pure ethylene is distilled twice. Separate the head and tail fractions. Collect the middle fraction and save it. 3.7 Preparation of standard solution 3.7.1 Boron standard solution: Take 5.7129 grams of high-purity boric acid (99.999%) and add it to a small amount of water, heat it slightly to dissolve it, transfer it to a 1-liter volumetric flask, dilute to the mark, shake and mix, 1 ml = 1 mg. 3.7.2 Iron standard solution: Weigh 1.0000 grams of metallic iron (purity not less than 99.99%), dissolve it in 30% 11:1 solution (it can also be dissolved in hydrochloric acid or sulfuric acid). After dissolution, heat to remove V02, cool, and transfer it to a 1-liter volumetric flask. Dilute to the mark with water and shake and mix. 1 ml = 1 3.7.3 Magnesium standard solution: weigh 1.0000g of metal magnesium (purity not less than 99.99%), add 20ml of water, and slowly add 20ml of hydrochloric acid. After it is completely dissolved, heat and boil, cool, transfer to a 1-volume bottle, and dilute with water to the mark: 1ml = 1ml of magnesium.
3.7.4 Lead standard solution: weigh 1.0000g of metal lead (purity not less than 99.99%). Place in a 300ml beaker, add 1:2 nitric acid to dissolve it. After it is dissolved After finishing, heat to remove 0, cool, transfer to a 1L volumetric flask. Dilute with water to the mark, shake. 1=1mg. 3.7.5 Standard solution of lead: weigh 3.7349g of chromic acid (spectrally pure) that has been pre-baked at 105°C for 1 hour and cooled, dissolve in a small amount of water. Transfer to a 1L volumetric flask and dilute with water to the mark. Shake. 1ml=1mg. 3.7.6 Standard solution of manganese: weigh 1.0000g of metallic manganese (purity not less than 99.99%), wash off the surface oxide with dilute sulfuric acid before weighing. Wash with water to remove the acid and then dry. Add 10m nitric acid (1:1), heat to dissolve, drive off the oxidant, cool, transfer to a 1L volumetric flask. Dilute with water, shake. 1ml-1mg manganese. 3.7.7 Titanium standard solution: Weigh 1.0000 g of titanium (purity not less than 99.995) and place it in a 250 ml beaker. Add a little water, slowly add fluorinated acid to dissolve the sample, then add nitric acid to completely oxidize the low-valent titanium, add 10 ml of concentrated sulfuric acid, shake and evaporate on an electric stove until white smoke appears. Remove, cool and allow to cool. Dilute with 5% sulfuric acid to the mark of a 1 liter bottle. The acidity is about 10%. 1 ml-1 g titanium. 3.7.8 Pseudo-standard solution: Weigh 1.0000 g of titanium (purity not less than 99.99) and place it in a 300 ml beaker. Add 20 ml of water and 3 g of sodium hydrofluoride. After the solution is completely dissolved, slowly neutralize with hydrochloric acid until a precipitate appears, and heat for 20 min to dissolve it (carefully stirring continuously). Cool the solution and transfer it to a 1 liter volumetric flask. Dilute with water to the mark, shake, 1 ml = 1 mg aluminum.2
SJ 2594-85
3.7.9 Copper standard solution: weigh 1.0000 g of copper (purity not less than 99.99%) and place it in a 400 ml beaker, add 20 ml of nitrocarboxylic acid (1:1) to dissolve, heat on a sand bath to evaporate to nearly 10%, then add 10 ml of bromine. Carefully evaporate until white bubbles appear, cool, add water and boil. When the salts are completely dissolved, cool, and transfer to a 1 II volumetric flask. Dilute with water to the mark, shake: 1 ml-1 mg copper. 3.7.10 Zinc standard solution: Weigh 1.0000 g of metallic zinc (purity not less than 99.99%) into a 300 ml beaker, add 15 ml of hydrochloric acid, dissolve it, heat to boil for 10 minutes, cool, transfer to a 1 L flask, dilute to the mark with water, then 1 ml = 1 ml zinc. 3.7.11 Bare standard solution: Weigh 1.0000 g of metallic zinc (purity not less than 99.99%) into a 900 ml beaker, add 15 ml of hydrochloric acid, heat to dissolve in a water bath, boil for 2 minutes, cool, transfer to a 1 L flask, dilute to the mark with water, and mix. 1 ml=1 mg3.7.12 Standard solution: Weigh 1.0000 g of metal (purity not less than 99.99%) into a 300 ml beaker, add 50 ml of 1:1 nitric acid, heat in a water bath to dissolve, cool, add a small amount of water and boil, transfer the solution in the beaker into a 1 liter volumetric flask, cool to room temperature, dilute with water to the mark, shake, the concentration of this solution is maintained at 2-3%. 1 ml=1 mg vanadium.
3.7.13 Standard solution: Weigh 2.2963 g of ammonium vanadate (NELVO. spectrally pure), dissolve in 100 ml of solution containing 100 ml of sodium hydroxide, after dissolution, dilute it with sulfuric acid (1:1) to room temperature, transfer it into a 1 liter volumetric flask, dilute with water to the mark, shake, 1 ml=1 mg. 3.7.14 Prepare 1 ml = 1 μg boron, iron, magnesium, lead, chromium, chromium, aluminum, copper, zinc, vanadium, cobalt, and vanadium standard solutions, and dilute and mix them appropriately. Prepare mixed solutions containing various elements at the lowest values, and put them into clean and dry polyethylene bottles for use (the solution is hydrochloric acid medium, the acidity is about 2%). Elements
Magnesium, cobalt
μg/ml
Aluminum, aluminum, magnesium, ,
Lead, chromium, zinc
Vanadium, iron, vanadium,
Note: The internal standard elements can be selected as sodium, potassium, or potassium, and their concentrations can be selected and accurately prepared by the analyst according to different circumstances. At the same time, the internal standard elements are added to the sixth standard sample, and an appropriate amount of carrier can also be added. 3
4 Analysis process
4.1 Separation and enrichment
SJ 2594-85bzxz.net
Add 0.1 ml of ethanol to six cleaned and dried 50-well crucibles, and add 40 ml of silicon tetrahydride sample to one of the crucibles. Place the sample in a vaporizer: keep the temperature at about 50°C, and introduce high-purity fluorine gas to evaporate the sample (nitrogen flow should not exceed 1 Ⅱ/min). Take out the platinum and calcine it at 350°C for 15 minutes to remove organic matter. Cool it slightly, add 0.10 ml of mannitol to each crucible to wet the bottom of the crucible, and then add about 1 liter of hydrofluoric acid on a hot plate or water bath at 0°C. Add 0.2 ml of 1:1 hydrochloric acid and 0.1 ml of internal standard solution to each crucible to decompose the residue.
Drop 0.1 ml of the six-order standard solution prepared in advance onto the flat-head electrode sealed with polystyrene corrector (do two in parallel for each order). At the same time, transfer the sample and blank to the electrode head. Bake the electrode under an infrared lamp, transfer it into a 3℃ Mold furnace and bake for 1 minute. Then take the cooling spectrum. 4.2 Spectral conditions
Due to the different instruments and light sources used by each unit, the spectral conditions can be selected according to the evaporation line of each element. 4.3. Light measurement and data processing
H microphotometer uses P scale to measure the lower engraved analysis line. Boron (n)
Nickel (nm)
Manganese (nm)
Aluminum (nm)
305.08 (or 341.48)
Iron (nm)
Copper (nm)
Magnesium (nm)
Zinc (nm)
Non (nm)
Cobalt (nm)
Chromium (nm)
Vanadium (mm)
Note: The internal standard line interval depends on the selected internal standard element. According to the internal standard line, the absolute impurity content of the sample and the case is calculated by △P-~iug. The relative content can be calculated. Measured impurity mass in sample (μg) - impurity mass in blank (ue) x10-4 instrument
Wu Zhong: y sampling (ml)
Specific gravity g/em
Allowable error of various elements
Internal error ()
Allowable error ()
Allowable error (%)
Allowable error coupon (%)
Notes
=5×10 °
±2.5×109
±5×10*
±5×10#
SJ2594-85
±5x10 -
±5×10
15×10*
15×10#
2. 5×10 a
+2.5×10 *
=2. 5× 10 9
The error in the analytical method of this standard is specified to ensure the accuracy of the analysis results. When the difference between the analytical results obtained in parallel analysis of each sample is within twice the absolute value of the specified error (i.e. ± several), it shall be considered valid.
6.2 For routine analysis of general production, two (or more than three) samples shall be measured in parallel. In arbitration analysis, six samples shall be measured in parallel each time. Among the above measurement results, the data within the allowable error range shall be taken to find the average value as the analysis result. (The data that meet the allowable error range shall not be less than two for routine analysis and not less than four for case analysis.)
6.3 Since the impurity content in the analyzed silicon tetrachloride is very low, the result of the blank test must be low in number and small in fluctuation. Otherwise, this trace analysis cannot be carried out. A blank test is performed each time an analysis is performed. When the sample measurement result is greater than one times the blank value, the number can be reported. Otherwise, the blank value is reported. The standard deviation of the blank value in most units is about 5 times the blank value. The principle that the measurement value greater than 2 can be reported is adopted.
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