Method for analyzing mixed acid concentration of silicon etching solution

An analysis method and etching solution technology, which is applied in the direction of chemical analysis by titration method, can solve the problems of increased uncertainty, reduced aperture ratio, and long time consumption, and achieve the effect of improving accuracy and eliminating interference

Active Publication Date: 2020-10-09
SUZHOU JIMCEL ELECTRONICS NEW MATERIAL
10 Cites 3 Cited by

AI-Extracted Technical Summary

Problems solved by technology

If the acid concentration is too high, it will cause over-cutting, which will cause insufficient driving current and poor display. If the acid concentration is too low, it will cause insufficient etching and reduce the aperture ratio, which will seriously affect the quality of etching. The high precision of the formation gradually requires the miniaturization of the width of the pattern formation. For this, there is a stricter requirement for the concentration accuracy of hydrofluoric acid, nitric acid, and acetic acid.
[0003] Chinese patent CN 107796912A discloses a mixed acid that uses an aprotic polar organic solvent (alcohol, isopropanol, acetone, tetrahydrofuran, methyl ethyl ketone or dimethylpyrrolidone) to dilute hydrofluoric acid and nitric acid, and uses sodium hydroxide or potassium hydroxide Solution titrant carries out potentiometric titration to mixed acid to obtain the concentration of hydrofluoric acid and nitric acid in mixed acid; Monohydric alcohols (methanol or ethanol) and dihydric alcohols (ethylene glycol, 1,2-propanediol or 1,4-butanediol) are non-aqueous media of mixed acids, and potentiometric titration of mixed acid solutions of nitric acid, phosphoric acid and acetic aci...
View more

Abstract

The invention discloses a method for analyzing the mixed acid concentration of a silicon etching solution. The method comprises the steps of taking a mixed acid sample of nitric acid, hydrofluoric acid and acetic acid to be detected, respectively adding an aprotic organic solvent and an anti-precipitation interference solvent into the mixed acid sample to prepare a silicon etching mixed acid solution, and dropwise adding a calibrated strong alkali aqueous solution into the silicon etching mixed acid solution through an automatic potentiometric titrator until a first jump part, a second jump part and a third jump part respectively appear; and calculating the concentration of the silicon etching liquid mixed acid, namely nitric acid, hydrofluoric acid and acetic acid, according to the volumeof the strong alkali aqueous solution consumed by the midpoints of the first, second and third jump parts. The concentrations of nitric acid, hydrofluoric acid and acetic acid contained in the silicon etching solution are easily, quickly and accurately measured by a one-step method, automatic dropwise adding and automatic calculation of the titration result are realized; the method is efficient and quick, the precision is improved, and time and labor are saved.

Application Domain

Chemical analysis using titration

Technology Topic

SolventFluorhydric Acid +9

Image

  • Method for analyzing mixed acid concentration of silicon etching solution

Examples

  • Experimental program(3)

Example Embodiment

[0035] Example 1
[0036] A method for analyzing the mixed acid concentration of a silicon etching solution, which steps include:
[0037] (1) Use sodium hydroxide as the solute and pure water as the solvent, configure a strong alkali solution with a concentration range of 0.9-1.1mol/L, calibrate the concentration with a standard concentration of HCl solution, and take the nitric acid, hydrofluoric acid and acetic acid to be tested For the mixed acid sample, ethanol and cyclohexanol were added to the mixed acid sample to prepare a silicon etching mixed acid solution. The mass volume ratio of the mixed acid sample to the added solvent was 1g:100ml, and the added solvent was a mixed solution of ethanol and cyclohexanol. , The volume ratio of ethanol and cyclohexanol is 1:1, and the total volume of the mixed acid sample and the added solvent is quantitatively 100mL;
[0038] (2) Drop the calibrated strong alkali aqueous solution into the silicon etching mixed acid solution through an automatic potentiometer until the first, second, and third jumps appear respectively, such as figure 1 Shown
[0039] (3) Calculate the concentration of the mixed acid of silicon etching solution, namely nitric acid, hydrofluoric acid and acetic acid according to the volume of the strong alkali aqueous solution consumed at the midpoint of the first, second, and third jump parts
[0040] C HNO3 % = *100%
[0041] C HF %= *100%
[0042] C CH3COOH %= *100%
[0043] Where:
[0044] C—Concentration of strong alkali aqueous solution, mol/L
[0045] V 1 —Volume of strong alkali aqueous solution consumed at the midpoint of the first jump, mL
[0046] V 2 —Volume of strong alkali aqueous solution consumed at the midpoint of the second jump, mL
[0047] V 3 —Volume of strong alkali aqueous solution consumed at the midpoint of the third jump, mL
[0048] M 1 —The molar mass of nitric acid, g/mol [M(HNO 3 )=63.01]
[0049] M 2 —The molar mass of hydrofluoric acid, g/mol [M(HF)=20.01]
[0050] M 1 —The molar mass of acetic acid, g/mol [M(CH 3 COOH))=60.05]
[0051] m—The mass of the mixed acid of the silicon etching solution weighed in the test, g.
[0052] Carry out three parallel determinations, the three deviations of each acid concentration are all within 0.2%, then choose the middle value of the three determinations as the final determination result.

Example Embodiment

[0053] Example 2
[0054] This example is basically the same as Example 1, the difference is that the strong alkali solution is potassium hydroxide solution, the mass-volume ratio of the mixed acid sample to the added solvent is 1.7g:100ml, and the volume ratio of ethanol and cyclohexanol in the solvent is 8: 1.

Example Embodiment

[0055] Example 3
[0056] This example is basically the same as Example 1, the difference is that the strong alkali solution is potassium hydroxide solution, the mass volume ratio of the mixed acid sample and the added solvent is 0.6g:100ml, and the volume ratio of ethanol and cyclohexanol in the solvent is 5: 1.

PUM

no PUM

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.

Similar technology patents

Shooting method and shooting device

InactiveCN104159034Aeliminate distractionsImprove the shooting effect
Owner:NUBIA TECHNOLOGY CO LTD

Conversation voice optimizing method, apparatus and conversation terminal

InactiveCN106920559Aeliminate distractionsAlleviate poor call quality
Owner:QIKU INTERNET TECH SHENZHEN CO LTD

Classification and recommendation of technical efficacy words

  • eliminate distractions
  • High precision

Method and device and communication equipment of reducing interference of clock on radio frequency system

InactiveCN103152064Aeliminate distractionsAvoid Receive Performance Degradation
Owner:LENOVO MOBILE COMM TECH

Method for forecasting short-term power in wind power station

InactiveCN102102626AHigh precision
Owner:NORTH CHINA ELECTRIC POWER UNIV (BAODING) +1

Numerical control machine tool wear monitoring method

InactiveCN102091972AHigh precisionReal-time monitoring of tool wear
Owner:HUAZHONG UNIV OF SCI & TECH +1

Advertisement recommendation method and apparatus

ActiveCN104965890AHigh precisionPrecise screening
Owner:SHENZHEN TENCENT COMP SYST CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products