Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method of preparing alkali resistance ultra-pure silicasol with metal content smaller than 1PPM

一种金属杂质、硅溶胶的技术，应用在非金属元素、化学仪器和方法、氧化硅等方向，能够解决很难使用、抛光速度低、耐碱性差等问题，达到节约生产成本、降低成本、高抛光速度的效果

Active Publication Date: 2010-02-03
SUZHOU SIRIKA ELECTRONIC MATERIALS CO LTD
View PDF2 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] (1) Many materials such as silicon wafers, TEOS films used as insulating materials (ILD) in chips, etc. often need to be polished under strong alkaline conditions to obtain good results. Under alkaline conditions, the STOBER method The polishing speed of silica sol is often lower than that of silica sol produced by the water glass method. The biggest reason is that the silica sol produced by this method has poor alkali resistance compared with the silica sol produced from water glass. That is to say, at the same Under high pH conditions, the silica sol of the STOBER method is more easily dissolved by alkali
Therefore, it is difficult to use under strong alkaline conditions of PH>10
[0006] (2) The electronic-grade organosilane used as raw material is relatively expensive, and the reaction requires a large amount of electronic-grade methanol or ethanol as a solvent, so the cost is high

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Example 1: 20 g of distilled and purified tetramethoxysilane (TMOS) was dissolved in 100 g of 1.4% KOH aqueous solution, stirred and heated to a transparent colorless liquid (solution A).

[0035]In another container, 80 grams of tetramethoxysilane (TMOS) was dissolved in 400 grams of 0.1% sulfuric acid solution, and stirred until a colorless and transparent solution (solution B).

[0036] Heat solution A to boiling, add solution B dropwise to solution A at an even speed for 40 minutes, after completion, stir for 15 minutes, heat and distill off by-product methanol and part of water to obtain silica sol, concentration 20%, PH = 9.5. Tested by the principle of dynamic light scattering, the average particle size is 70nm.

[0037] The silica sol is tested by ICP mass spectrometry after being treated with HF-HNO3 acid, and the following impurity content is obtained:

[0038] Al Ca Fe K Mg Na Zn

[0039] <100ppb <100ppb <100ppb 5750ppm <100ppb <100ppb <100ppb

[0040] Ot...

Embodiment 2

[0041] Example 2: 200 grams of 2.2% KOH (weight concentration) aqueous solution was placed in a container (solution A).

[0042] In another container, 200 grams of tetramethoxysilane (TMOS) was dissolved in 500 grams of 0.2% sulfuric acid solution, and stirred until a colorless and transparent solution (solution B).

[0043] Heat solution A to boiling, add solution B dropwise to solution A at an even speed for 100 minutes, after completion, stir for 15 minutes, heat and distill out by-product methanol and a part of water.

[0044] The obtained silica sol has a concentration of 20% and a pH of 9.5. Tested by the principle of dynamic light scattering, the average particle size is 72nm.

[0045] The silica sol is tested by ICP mass spectrometry to obtain the following impurity content:

[0046] Al Ca Fe K Mg Na Zn

[0047] <100ppb <100ppb <100ppb 8840ppm <100ppb <100ppb <100ppb

[0048] Other metallic impurities were not detected. The above results show that the silica sol ...

Embodiment 3

[0049] Embodiment three: the ammoniacal liquor of 20 gram 28% is mixed with the water of 100 gram (solution A), in another container 80 gram tetramethoxysilane (TMOS) is dissolved in the sulfuric acid solution of 400 gram 0.1% (solution A) B).

[0050] Heat solution A to boiling, add solution B dropwise to solution A at a constant speed for 40 minutes, after completion, stir for 15 minutes, heat to evaporate by-product methanol and part of water, and add a certain amount of ammonia water dropwise in order to maintain the pH value.

[0051] The obtained silica sol has a concentration of 20% and a pH of 9.

[0052] Tested by the principle of dynamic light scattering, the average particle size is 65nm. Test by ICP mass spectrometry, obtain following impurity content:

[0053] Al Ca Fe K Mg Na Zn

[0054] <100ppb <100ppb <100ppb <100ppb <100ppb <100ppb <100ppb

[0055] Other metallic impurities were not detected.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
composition ratioaaaaaaaaaa
Login to View More

Abstract

The invention discloses a making method of alkaline-resistance hyperhigh pure silicasol, which comprises the following steps: 1. adopting distilled pure organic silicane as raw material; dissolving inthe inorganic acid or organic acid to obtain acid metasilicate acid solution; 2. dissolving rectified organic silicane in the inorganic alkaline or organic alkaline solution to obtain the alkaline silicon solution; or diluting inorganic alkaline or organic alkaline solution to obtain alkaline solution without silicon; 3. reacting acid metasilicate acid solution and alkaline solution without silicon under 105 deg.c; obtaining the silicasol; 4. heating silicasol under normal pressure or decompressing condition to boil to remove carbinol or alcohol and partial water; obtaining the product with density over 20%.

Description

technical field [0001] The invention relates to a method for preparing alkali-resistant ultra-high-purity silica sol with metal impurity content less than 1PPM. Background technique [0002] Silica sol is a suspension dispersion of silicon dioxide particles in water. Ultra-high-purity silica sol is mainly used in precision polishing of semiconductor materials, such as silicon wafers and germanium wafers, as well as in the chemical process of multi-layer wiring of integrated circuits. In the mechanical planarization (CMP) process, as well as in the precision polishing of hard disk aluminum substrates, it is the main component in the semiconductor material polishing fluid, and is an indispensable and important consumable in the modern microelectronics industry. Ultra-high-purity silica sol is the highest-grade product among silica sols. Its most important feature is that the content of metal impurities is extremely low, generally at 10PPM or even 1PPM, or less than one part pe...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/14
CPCC01B33/141
Inventor 王宇湖张宁
Owner SUZHOU SIRIKA ELECTRONIC MATERIALS CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com