WO1999012026A1 - Procede d'analyse quantitative, analyseur quantitatif, procede de controle d'attaque pour fluide acide mixte en processus d'attaque, et production dudit fluide - Google Patents
Procede d'analyse quantitative, analyseur quantitatif, procede de controle d'attaque pour fluide acide mixte en processus d'attaque, et production dudit fluide Download PDFInfo
- Publication number
- WO1999012026A1 WO1999012026A1 PCT/JP1998/003808 JP9803808W WO9912026A1 WO 1999012026 A1 WO1999012026 A1 WO 1999012026A1 JP 9803808 W JP9803808 W JP 9803808W WO 9912026 A1 WO9912026 A1 WO 9912026A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- acid
- concentration
- mixed
- nitric
- hydrofluoric
- Prior art date
Links
- 239000002253 acid Substances 0.000 title claims abstract description 178
- 238000005530 etching Methods 0.000 title claims abstract description 91
- 238000000034 method Methods 0.000 title claims abstract description 91
- 238000004445 quantitative analysis Methods 0.000 title claims description 37
- 239000012530 fluid Substances 0.000 title abstract 4
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims abstract description 148
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 104
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 104
- 238000004448 titration Methods 0.000 claims abstract description 43
- -1 hexafluorosilicic acid Chemical compound 0.000 claims abstract description 40
- 238000006386 neutralization reaction Methods 0.000 claims abstract description 22
- 238000004519 manufacturing process Methods 0.000 claims abstract description 18
- 150000007513 acids Chemical class 0.000 claims abstract description 17
- 238000004458 analytical method Methods 0.000 claims abstract description 10
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 40
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 38
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 19
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 18
- 238000000870 ultraviolet spectroscopy Methods 0.000 claims description 14
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 12
- 229910052710 silicon Inorganic materials 0.000 claims description 12
- 239000010703 silicon Substances 0.000 claims description 12
- 235000012431 wafers Nutrition 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 6
- 238000004847 absorption spectroscopy Methods 0.000 claims description 5
- 230000003247 decreasing effect Effects 0.000 claims description 2
- 238000007654 immersion Methods 0.000 claims description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims 1
- 229910052739 hydrogen Inorganic materials 0.000 claims 1
- 239000001257 hydrogen Substances 0.000 claims 1
- 239000000243 solution Substances 0.000 description 74
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 48
- 239000012488 sample solution Substances 0.000 description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 5
- 239000012086 standard solution Substances 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 238000003918 potentiometric titration Methods 0.000 description 4
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- 238000002835 absorbance Methods 0.000 description 3
- 239000003125 aqueous solvent Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- MVPPADPHJFYWMZ-UHFFFAOYSA-N chlorobenzene Chemical compound ClC1=CC=CC=C1 MVPPADPHJFYWMZ-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 238000002798 spectrophotometry method Methods 0.000 description 2
- FYSNRJHAOHDILO-UHFFFAOYSA-N thionyl chloride Chemical compound ClS(Cl)=O FYSNRJHAOHDILO-UHFFFAOYSA-N 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 238000011437 continuous method Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- LYGJENNIWJXYER-UHFFFAOYSA-N nitromethane Chemical compound C[N+]([O-])=O LYGJENNIWJXYER-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- OVYTZAASVAZITK-UHFFFAOYSA-M sodium;ethanol;hydroxide Chemical compound [OH-].[Na+].CCO OVYTZAASVAZITK-UHFFFAOYSA-M 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/33—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using ultraviolet light
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
- H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
- H01L21/30604—Chemical etching
Definitions
- the present invention relates to a method for quantitatively analyzing a mixed acid solution in an etching process, a quantitative analysis device, a method for controlling etching, and a method for producing the mixed acid solution.
- etching of a silicon wafer used for forming a semiconductor circuit usually uses a mixed acid solution of hydrofluoric acid, nitric acid, and acetic acid, and, if necessary, a mixed acid solution combining phosphoric acid and sulfuric acid.
- a mixed acid solution of hydrofluoric acid, nitric acid, and acetic acid, and, if necessary, a mixed acid solution combining phosphoric acid and sulfuric acid.
- the consumption of nitric acid and hydrofluoric acid etc. is replenished to the mixed acid solution for use after use, and care has been taken to maintain the same etching state at all times.
- quantitative analysis of each component of the used mixed acid solution has been performed.
- the present invention has been made in view of the above circumstances, and has as its object to provide an etching process that can obtain the concentration of each acid component in a simple manner and in a short time. It is an object of the present invention to provide a method and apparatus for quantitative analysis of a mixed acid solution. Another object of the present invention is to provide an industrially advantageous etching control method and a method for producing the mixed acid solution. Disclosure of the invention
- the present inventors have conducted various studies to solve the above-described problems, and as a result, in performing the composition analysis of the mixed acid solution, by combining a specific quantitative analysis method, the concentration of each acid component included in the mixed acid solution is determined.
- the present invention has been achieved by conceiving that it is possible to obtain a small amount by using analysis means and in a short time.
- the present inventors have found that the adoption of the specific means can achieve an industrially advantageous etching control method and the above-mentioned mixed acid solution production method.
- a first gist of the present invention is an etching process that includes nitric acid as a strong acid component, and further includes one type of hydrofluoric acid and / or another strong acid (excluding nitric acid and hydrofluoric acid) and hexafluorosilicic acid.
- the concentration of hydrofluoric acid and Z or other acid components is quantitatively analyzed by nonaqueous neutralization titration, and only the concentration of nitric acid is quantitatively analyzed by ultraviolet spectrophotometry.
- the method according to (1) to (3) described above is characterized in that the concentration of nitric acid, hydrofluoric acid and / or the above-mentioned other strong acid components is determined separately for quantitative analysis of a mixed acid solution in an etching process.
- the mixed acid solution contains only nitric acid and hydrofluoric acid as strong acid components
- the total concentration of nitric acid and hexafluorosilicic acid and the concentration of hydrofluoric acid are classified according to the above-mentioned non-water immersion titration method.
- the concentration of nitric acid, hydrofluoric acid and hexafluorosilicic acid is obtained by subtracting the concentration of nitric acid by the above-mentioned ultraviolet absorption spectrophotometry from the total concentration to obtain the concentration of hexafluorosilicic acid. . W
- the mixed acid solution contains one of nitric acid, hydrofluoric acid and other strong acids (excluding nitric acid and hydrofluoric acid) as a strong acid component, and the other strong acid is sulfuric acid or phosphoric acid
- the above non-water The total concentration of nitric acid concentration, hexafluorosilicic acid concentration and sulfuric acid or phosphoric acid concentration and hydrofluoric acid concentration are obtained by the sum titration method, and the sulfuric acid or phosphoric acid concentration is determined by dry-up method quantitative analysis.
- the concentration of hexafluorosilicic acid From the total concentration to obtain the concentration of hexafluorosilicic acid by subtracting the concentration of nitric acid by the ultraviolet absorption spectrophotometry and the concentration of sulfuric acid or phosphoric acid by the quantitative analysis of the dry-up method from the total concentration. Calculate the concentrations of nitric acid, nitric acid, hydrofluoric acid, sulfuric acid or phosphoric acid, and hexafluorosilicic acid separately.
- the mixed acid solution contains only one of nitric acid and other strong acids (excluding nitric acid and hydrofluoric acid) as a strong acid component, the concentration of nitric acid obtained by the above non-aqueous neutralization titration method and the other By subtracting the concentration of nitric acid by the above-mentioned ultraviolet absorption spectrophotometry from the total concentration with the strong acid, the concentration of the above-mentioned other strong acids is obtained, and the concentrations of the nitric acid and the above-mentioned other strong acids are separately obtained.
- nitric acid and other strong acids excluding nitric acid and hydrofluoric acid
- the second aspect of the present invention is to provide a mixed acid solution in an etching process containing nitric acid as a strong acid component, and further containing one of hydrofluoric acid and a non-acid or another strong acid (excluding nitric acid and hydrofluoric acid).
- a quantitative analysis device for a mixed acid solution in an etching process characterized by being provided.
- the third gist of the present invention is that a silicon wafer is etched by a mixed acid solution containing nitric acid as a strong acid component, and further containing one of hydrofluoric acid and another strong acid (excluding nitric acid and hydrofluoric acid). After that, the mixed acid solution is quantitatively analyzed, and based on the quantitative analysis result of the composition, each acid component having a reduced concentration is used in the etching step.
- the present invention resides in an etching control method characterized by replenishment.
- a fourth aspect of the present invention is a method for producing a mixed acid solution used in a silicon wafer etching process, wherein the mixed acid solution is discharged from the etching step, contains nitric acid as a strong acid component, and further contains hydrofluoric acid and Z or An etching process characterized by adding each acid component having a reduced concentration in the above-mentioned etching step to a mixed acid solution containing one of other strong acids (excluding nitric acid and hydrofluoric acid) and hexafluorosilicic acid.
- the method for producing a mixed acid solution is a method for producing a mixed acid solution.
- the quantitative analysis method of the present invention is used in the quantitative analysis device of the present invention, and the quantitative analysis device of the present invention can be used in the etching control method of the present invention. Perform based on. Then, the method for producing a mixed acid solution according to the present invention will be described.
- the above-mentioned etching control method involves etching a silicon wafer, quantitatively analyzing the mixed acid solution after that, and replenishing each of the acid components having a reduced concentration to the etching process based on the quantitative analysis result of the composition. Consists of
- the above-mentioned etching process is a process which is usually performed in a silicon wafer polishing step when manufacturing a silicon wafer.
- the above-mentioned mixed acid solution for etching treatment contains nitric acid, and further contains one type of hydrofluoric acid and / or another strong acid (excluding nitric acid and hydrofluoric acid). Used together. If necessary, phosphoric acid, sulfuric acid and the like are used in combination.
- the mixed acid solution before the etching process contains hydrofluoric acid in addition to nitric acid, in addition to the acid component of the above-mentioned mixed acid solution for the etching process, it is a reaction product with silicon which is a material to be etched by the etching process. Hexafluorosilicic acid is produced, and the mixed acid solution after the above-mentioned etching treatment contains hexafluorosilicic acid.
- the quantitative analysis of the mixed acid solution after the above-mentioned etching treatment is performed by quantitatively analyzing the concentrations of nitric acid, hydrofluoric acid and Z or other strong and weak acids in the mixed acid solution after the etching treatment of the silicon wafer by a non-aqueous neutralization titration method. Then, only the concentration of nitric acid is quantitatively analyzed by ultraviolet spectrophotometry.
- the concentration of nitric acid in the mixed acid solution after the above etching treatment is usually 30 to 60% by weight, preferably 35 to 45% by weight, and the concentration of hydrofluoric acid is usually 2 to 20% by weight, preferably 2 to 20% by weight.
- the concentration of acetic acid is usually 10 to 30% by weight, preferably 15 to 25% by weight, and the concentration of hexafluorosilicic acid is usually 1 to 10% by weight, preferably 3 to 6% by weight.
- the concentration of water is usually 20 to 40% by weight, preferably 30 to 35% by weight.
- the above-mentioned non-aqueous neutralization titration method is basically a neutralization titration method using a non-aqueous solvent as a solvent for dissolving a component to be titrated in a mixed acid solution after an etching treatment.
- a non-aqueous solvent examples include benzene, dioxane, acetone, acetonitrile, hydrocarbons, chloroform, chlorobenzene, methyl isobutyl ketone, ether, thionyl chloride, and nitromethane. It is a target.
- the concentration of each component (acid component) to be titrated in the titration sample solution obtained by dissolving the mixed acid solution after the etching treatment in the above-mentioned non-aqueous solvent is usually 1 to 100 milliequivalents, preferably 10 ⁇ 25 milliequivalents.
- the titration sample solution contains a small amount of water.
- the amount of water contained is usually 1 to 10% by weight, preferably 2 to 5% by weight.
- a titration standard solution used in the above-described non-aqueous neutralization titration method for example, an alcohol solution of sodium hydroxide is used. Usually, ethanol is suitably used as such an alcohol.
- the sodium hydroxide concentration of the above-mentioned titration standard solution is, for example, 1/10 normal (N).
- a potentiometric titration method is practical. Then, a known measuring device can be used for the measurement.
- the concentrations of hydrofluoric acid and acetic acid can be determined separately from the concentrations of strong acids such as nitric acid.
- the concentrations of nitric acid and hexafluorosilicic acid cannot be obtained separately because their potential difference curves overlap. Therefore, in the present invention, in addition to the quantitative analysis by the non-aqueous neutralization titration method, a quantitative analysis of the concentration of nitric acid is separately performed by an ultraviolet absorption spectrophotometry.
- Ultraviolet absorption spectroscopy is a method of determining the absorbance of a titration sample solution at light having a wavelength of around 302.0 nm, and determining the concentration of nitric acid from the absorbance.
- the quantitative analysis of nitric acid alone can be performed without being affected by the presence of other mixed substances.
- the specific measurement by the ultraviolet absorption spectrophotometry can be performed by a known method.
- the following methods (1) to (3) show that nitric acid, hydrofluoric acid and / or other strong acids can be obtained.
- the concentration of the component can be determined separately.
- the mixed acid solution contains only nitric acid and hydrofluoric acid as strong acid components
- the total concentration of nitric acid and hexafluorosilicic acid and the concentration of hydrofluoric acid are classified by the above-mentioned non-aqueous neutralization titration method.
- the concentration of nitric acid, hydrofluoric acid, and hexafluorosilicic acid are obtained by subtracting the concentration of nitric acid by the above-mentioned ultraviolet absorption spectrophotometry from the total concentration to obtain the concentration of hexafluorosilicic acid.
- the mixed acid solution contains one of nitric acid, hydrofluoric acid and other strong acids (excluding nitric acid and hydrofluoric acid) as a strong acid component and the other strong acid is sulfuric acid or phosphoric acid
- the above non-water The total concentration of the concentration of nitric acid, the concentration of silicic acid at the mouth of the mouth and the concentration of sulfuric acid or phosphoric acid, and the concentration of hydrofluoric acid are obtained by the sum titration method. To obtain the concentration of
- the concentration of nitric acid and hydrofluoric acid is obtained by subtracting the concentration of nitric acid by the above-mentioned ultraviolet absorption spectrometry and the concentration of sulfuric acid or phosphoric acid by the dry-up method quantitative analysis from the above total concentration to obtain the concentration of hexafluorosilicic acid. Determine the concentrations of sulfuric acid, sulfuric acid or phosphoric acid, and hexafluorosilicic acid separately.
- a non-volatile acid other than sulfuric acid or phosphoric acid is expelled by heating a titration sample solution on a boiling water bath, and then the above-mentioned non-aqueous neutralization titration method or other appropriate method is used.
- This is an analytical method that quantitatively analyzes the concentration of sulfuric acid or phosphoric acid. With this method, only the concentration of sulfuric acid or phosphoric acid can be determined.
- the mixed acid solution contains only one of nitric acid and other strong acids (excluding nitric acid and hydrofluoric acid) as a strong acid component
- the concentration of nitric acid obtained by the above non-aqueous neutralization titration method and the above By subtracting the concentration of nitric acid by the above-mentioned ultraviolet absorption spectrophotometry from the total concentration with the strong acid, the concentration of the above-mentioned other strong acid is obtained, and the concentration of the nitric acid and the above-mentioned other strong acid is separately obtained.
- the replenishment amount of each acid component whose concentration has been reduced by the above-mentioned etching process to the etching process is determined by comparing the quantitative analysis value or standard value of the mixed acid solution for the etching process with the quantitative analysis value of the mixed acid solution after the etching process. It can be obtained as the product of the required concentration difference and the amount of the mixed acid solution for etching treatment.
- the mixed acid solution after the etching process contains the chemical reaction accompanying the etching process.
- hexafluorosilicic acid which is a strong acid, is generated, accumulated and contained.
- This hexafluorosilicic acid can be appropriately treated by a method such as renewal of a mixed acid solution for etching treatment.
- water is produced together with hexafluorosilicic acid by the above chemical reaction, and nitric acid and hydrofluoric acid are consumed. Acetic acid is not consumed, but its concentration decreases with the production of hexafluorosilicic acid and water.
- a measuring device by a potentiometric titration method is preferable, and an automatic measuring type measuring device is particularly preferable.
- a known device can be used as such a device.
- An apparatus that implements both of the above means may be an apparatus having both of the above two means, or may be a set of apparatuses each having the above means.
- the concentration of acetic acid can be determined separately from the concentration of strong acid by the above-mentioned non-aqueous neutralization titration method.
- the etching control method of the present invention may be performed by any of a batch method in which the mixed acid solution after the etching treatment is not circulated to the etching step or a continuous method in which the mixed acid solution after the etching treatment is circulated to the etching step. Good.
- the replenishment of the acid components (nitric acid, hydrofluoric acid, and acetic acid) whose concentration has been reduced to the etching process (etching tank) is performed as follows. That is, in the case of the batch type, a method of directly adding to the etching step is adopted, and in the case of the continuous type, in addition to the above, a method of adding to a mixed acid solution circulated in the etching step can also be adopted.
- each acid component may be separately added to the circulated mixed acid solution, or may be added after mixing in advance.
- the process proceeds to the etching process of hexafluorosilicic acid and water. In order to prevent excessive accumulation of a part of the mixed acid solution in the etching step, a part of the mixed acid solution is appropriately extracted.
- a mixed acid discharged from the etching step and containing nitric acid as a strong acid component, and further containing one of hydrofluoric acid and another strong acid (excluding nitric acid and hydrofluoric acid) and hexafluorosilicic acid Add each acid component whose concentration has been reduced in the above etching step to the solution.
- Such an operation itself is included in the continuous etching control method described above.
- a high-purity mixed acid solution containing nitric acid, hydrofluoric acid, acetic acid, hexafluorosilicic acid and water as described above can be produced by using high-purity silica as one of the raw materials.
- the above silica is added to a mixed acid solution of nitric acid, hydrofluoric acid, and acetic acid to generate hexafluorosilicic acid.
- the above-described production method is not economical because high-purity silica is expensive, and has a problem in terms of environment because a nitric oxide-containing gas is generated by the oxidizing action of nitric acid.
- Such environmental problems can be avoided by a method in which nitric acid is added to a mixed acid solution containing no nitric acid and then nitric acid is added, but in this case, a two-stage mixing and dissolving operation is required. There is a benefit.
- the disadvantages described above are eliminated at once, and furthermore, a remarkable economic effect such as the effective use of the used mixed acid solution discharged from the etching step. Is obtained. Also, since the amount of mixed acid solution containing strong acid components is greatly reduced, the effect on environmental issues is very large.
- Nitric acid, hydrofluoric acid, and acetic acid containing 39.3 wt%, 11.4 wt%, and 20.9 wt%, respectively, with the remainder being water using a mixed acid solution for etching (three kinds of mixed acid solutions) to etch silicon wafers was done. Thereafter, the mixed acid solution after the treatment was diluted as follows and used for an analysis sample. First, about 100 ml of decarbonated water is accurately weighed and taken into a 100 ml polyethylene bottle, and 4 ml of the mixed acid solution after the above-mentioned etching treatment is accurately weighed with a pipette, added, and shaken well to mix. To prepare a titration sample solution.
- the drop volume-potential difference curve showed three inflection points corresponding to the equivalence points of nitric acid and hexafluorosilicic acid, hydrofluoric acid, and acetic acid.
- the potential differences at each inflection point were 135 mV, -38 mV, and -379 mV, respectively, and the drops were 11.08 ml, 5.62 ml, and 5.22 ml, respectively.
- the amounts of these drops were 39.3 wt%, 7.5 wt% and 20.9 wt%, respectively, of the concentration of nitric acid and hexafluorosilicic acid, the concentration of hydrofluoric acid and the concentration of acetic acid before dilution of the mixed acid solution after treatment.
- the amounts of these drops were 39.3 wt%, 7.5 wt% and 20.9 wt%, respectively, of the concentration of nitric acid and hexafluorosilicic acid, the concentration of hydrofluoric acid and the concentration of acetic acid before dilution of the mixed acid solution after treatment. was equivalent.
- the concentrations of nitric acid, hydrofluoric acid, acetic acid, and hexafluorosilicic acid in the mixed acid solution after the etching treatment were 34.5% by weight, 7.5% by weight, 20.9% by weight, and 4.6% by weight, respectively, with the balance being water.
- Met Comparing this concentration with the concentrations of nitric acid, hydrofluoric acid, acetic acid, and hexafluorosilicic acid in the mixed acid solution before the etching treatment, the nitric acid was -4.8% by weight, hydrofluoric acid was -3.9% by weight, and acetic acid was -1.0% by weight.
- Xafluorosilicic acid increased or decreased by + 4.6% by weight.
- nitric acid, hydrofluoric acid and acetic acid were replenished to the mixed acid solution after the above etching treatment in accordance with the above-mentioned increase and decrease. Then, the silicon wafer was again subjected to the etching process. A part of the mixed acid solution after the above etching treatment was periodically purged in order to prevent excessive accumulation of hexafluorosilicic acid.
- the non-aqueous neutralization titration method under specific conditions and the ultraviolet absorption spectroscopy method, and if necessary, further combining the dry-up method
- a quantitative analysis method and a quantitative analysis device that can easily determine the concentration of each component of a solution in a short time.
- an industrially advantageous etching control method and a method for producing the above mixed acid solution are provided. Therefore, the industrial value of the present invention is great.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Pathology (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Immunology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Molecular Biology (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Abstract
L'invention concerne un procédé permettant d'analyser un fluide acide mixte en processus d'attaque, qui consiste à utiliser de l'acide nitrique comme acide fort et, en outre, de l'acide fluorhydrique et/ou un autre acide fort (sauf l'acide nitrique et l'acide fluorhydrique) ainsi que de l'acide hexafluorosilicique, sachant que la concentration d'acide fluorhydrique et/ou des autres acides est déterminée quantitativement par titration de neutralisation non aqueuse, et que la concentration d'acide nitrique seulement est évaluée quantitativement de manière séparée par absorptiométrie des rayons UV, ce qui revient à déterminer séparément chacune des concentrations de l'acide nitrique, de l'acide fluorhydrique et/ou des autres acides forts considérés. Le procédé analytique décrit est simple et permet de déterminer la concentration de chaque acide en peu de temps. En outre, ce procédé est utilisable comme procédé de contrôle d'attaque et dans l'élaboration du fluide acide mixte susmentionné.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9/247752 | 1997-08-28 | ||
JP24775297 | 1997-08-28 | ||
JP32226397 | 1997-11-07 | ||
JP9/322263 | 1997-11-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1999012026A1 true WO1999012026A1 (fr) | 1999-03-11 |
Family
ID=26538402
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1998/003808 WO1999012026A1 (fr) | 1997-08-28 | 1998-08-27 | Procede d'analyse quantitative, analyseur quantitatif, procede de controle d'attaque pour fluide acide mixte en processus d'attaque, et production dudit fluide |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO1999012026A1 (fr) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2003036706A1 (fr) * | 2001-10-24 | 2003-05-01 | Sumitomo Mitsubishi Silicon Corporation | Procede et dispositif de gravure de plaquettes de silicium et procede d'analyse d'impuretes |
CN102778532A (zh) * | 2012-08-10 | 2012-11-14 | 深圳市华星光电技术有限公司 | 铝蚀刻液混酸浓度的电位滴定方法 |
US8945934B2 (en) | 2012-08-10 | 2015-02-03 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Potentiometric titration method for measuring concentration of acid mixture of aluminum etchant |
CN112710777A (zh) * | 2020-12-04 | 2021-04-27 | 湖北兴福电子材料有限公司 | 一种混酸中氟硼酸的检测方法 |
US11610783B2 (en) | 2014-07-30 | 2023-03-21 | Corning Incorporated | Ultrasonic tank and methods for uniform glass substrate etching |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01242940A (ja) * | 1988-03-24 | 1989-09-27 | Fuji Electric Co Ltd | 硝酸イオン濃度と亜硝酸イオン濃度の測定方法 |
JPH03107477A (ja) * | 1989-09-22 | 1991-05-07 | Kawasaki Steel Corp | 半導体材料の湿式処理方法および装置 |
JPH06163509A (ja) * | 1992-07-27 | 1994-06-10 | Mitsubishi Kasei Corp | エッチング処理液の制御方法 |
-
1998
- 1998-08-27 WO PCT/JP1998/003808 patent/WO1999012026A1/fr active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH01242940A (ja) * | 1988-03-24 | 1989-09-27 | Fuji Electric Co Ltd | 硝酸イオン濃度と亜硝酸イオン濃度の測定方法 |
JPH03107477A (ja) * | 1989-09-22 | 1991-05-07 | Kawasaki Steel Corp | 半導体材料の湿式処理方法および装置 |
JPH06163509A (ja) * | 1992-07-27 | 1994-06-10 | Mitsubishi Kasei Corp | エッチング処理液の制御方法 |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2003036706A1 (fr) * | 2001-10-24 | 2003-05-01 | Sumitomo Mitsubishi Silicon Corporation | Procede et dispositif de gravure de plaquettes de silicium et procede d'analyse d'impuretes |
US7686973B2 (en) | 2001-10-24 | 2010-03-30 | Sumitomo Mitsubishi Silicon Corporation | Silicon wafer etching method and apparatus, and impurity analysis method |
CN102778532A (zh) * | 2012-08-10 | 2012-11-14 | 深圳市华星光电技术有限公司 | 铝蚀刻液混酸浓度的电位滴定方法 |
WO2014023045A1 (fr) * | 2012-08-10 | 2014-02-13 | 深圳市华星光电技术有限公司 | Procédé de titrage potentiométrique de la concentration d'un mélange d'acides dans un liquide pour la gravure de l'aluminium |
US8945934B2 (en) | 2012-08-10 | 2015-02-03 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Potentiometric titration method for measuring concentration of acid mixture of aluminum etchant |
CN102778532B (zh) * | 2012-08-10 | 2016-03-09 | 深圳市华星光电技术有限公司 | 铝蚀刻液混酸浓度的电位滴定方法 |
US11610783B2 (en) | 2014-07-30 | 2023-03-21 | Corning Incorporated | Ultrasonic tank and methods for uniform glass substrate etching |
CN112710777A (zh) * | 2020-12-04 | 2021-04-27 | 湖北兴福电子材料有限公司 | 一种混酸中氟硼酸的检测方法 |
CN112710777B (zh) * | 2020-12-04 | 2022-04-22 | 湖北兴福电子材料有限公司 | 一种混酸中氟硼酸的检测方法 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JPH11194120A (ja) | エッチングプロセスにおける混酸液の定量分析方法、定量分析装置およびエッチング制御方法ならびに上記の混酸液の製造方法 | |
Adam et al. | Hypochlorous acid decomposition in the pH 5-8 region | |
Demutskaya et al. | Photometric determination of ammonium nitrogen with the nessler reagent in drinking water after its chlorination | |
US20060097144A1 (en) | Automated in-process ratio mass spectrometry | |
Gimeno et al. | A potentiometric titration for H 2 O 2 determination in the presence of organic compounds | |
JP2007024634A (ja) | ヒ素・リン・シリカの高感度吸光検出法 | |
WO1999012026A1 (fr) | Procede d'analyse quantitative, analyseur quantitatif, procede de controle d'attaque pour fluide acide mixte en processus d'attaque, et production dudit fluide | |
TWI795600B (zh) | 用於蝕刻劑溶液中之多種矽化合物之選擇性監測的方法及設備 | |
EP1355728A2 (fr) | Spectrometrie de masse par dilution isotopique, automatisee, en cours de fabrication | |
Langner et al. | Raman spectroscopic determination of the degree of dissociation of nitric acid in binary and ternary mixtures with HF and H2SiF6 | |
CZ2001551A3 (cs) | Způsob řízení čisticích lázní | |
KR101439901B1 (ko) | 질산의 농도 측정 방법 | |
US6797237B2 (en) | Oxidation decomposition type element analyzer | |
CN113237841B (zh) | 一种蚀刻液中过氧化氢含量的检测方法 | |
KR20090067862A (ko) | 불산이 포함된 혼합용액 중 불산 농도의 신속한 분석을위한 1회용 분석 Kit의 제조방법 | |
Carpio et al. | Determination of boron and phosphorus in borophosphosilicate thin films on silicon substrates by capillary electrophoresis | |
JP3688593B2 (ja) | 珪素材料中の不純物分析方法 | |
JP4186214B2 (ja) | ケイモリブデン酸逆抽出法およびケイモリブデン酸(青)吸光光度法によるケイ素定量法 | |
CN114264769A (zh) | 一种电子级混酸体系的组分浓度检测方法 | |
EP2655248B1 (fr) | Procédé de préparation, de stockage, de transport et d'analyse de solutions de dioxyde de chlore | |
JPH05216241A (ja) | 現像液の自動希釈装置 | |
JP2005300198A (ja) | 低濃度硫化水素の分析方法 | |
JPS62172244A (ja) | 溶剤と弗化水素との混合液の濃度測定方法 | |
Radić et al. | Kinetic-potentiometric determination of aluminium in acidic solution using a fluoride ion-selective electrode | |
CN116754349B (zh) | 基于icp-oes的硫化锂杂质元素的消解方法及其含量测定的方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): KR US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
NENP | Non-entry into the national phase |
Ref country code: KR |
|
122 | Ep: pct application non-entry in european phase |