Method for purifying Nano silica sol dedicated for super large scale integration

A large-scale integrated circuit, nano-silica sol technology, applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve the problems of slow change of pH value on the surface of colloidal particles, poor purification effect, thickening of hydration film, etc. , to achieve significant purification effect, long service life, and the effect of reducing the content

Inactive Publication Date: 2008-01-23
HEBEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

h + Slowly enter the compact layer, so that the pH value on the surface of the colloidal particles changes slowly, and a large amount of Na in the silica sol + and other metal cations by H + replaced by H + The hydration capacity of Na + and other metal cations, these H + The hydration film around the colloidal particles is thickened, which seriously hinders the Na + and other metal cations with H + mutual replacement speed
Therefore, purely using cation exchange resin to purify silica sol, although part of the metal ions of silica sol can be removed, there are still a large amount of metal ions inside, the purification effect is not good, and the metal ion content increases with the increase in the number of cation exchange resin treatments. not much will change

Method used

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  • Method for purifying Nano silica sol dedicated for super large scale integration
  • Method for purifying Nano silica sol dedicated for super large scale integration

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Inject 1752ml, 3% hydrochloric acid solution into an ion exchange column equipped with 800ml Nankai brand 001×7 type cation exchange resin and stir. After stirring for 3 minutes, let it stand for stratification, remove the upper layer solution, and rinse the remaining cations with deionized water. Exchange the resin until its pH value is between 2-2.5 to obtain an acidic cation exchange resin.

[0032] Then the concentration is 30%, the particle diameter is 22nm, the alkaline silica sol 536g that metal ion content is higher than 100ppm joins in the above-mentioned acidic cation exchange resin of 400ml under the situation of continuous stirring, exchange 15min under the situation of stirring, measure simultaneously Exchange the Zeta potential of the solution so that its absolute value is above 30mv, then stop stirring, leave to stand for stratification, and discharge to obtain acidic silica sol.

[0033] Then get 834ml, 3% sodium hydroxide solution and inject in the ion ...

Embodiment 2

[0038] Inject 2102.2ml, 5% hydrochloric acid solution into an ion exchange column equipped with 1600ml American Amberjet 1200Na cation exchange resin for stirring. After stirring for 5 minutes, let it stand for stratification, remove the upper layer solution, and rinse the remaining cation exchange resin with deionized water. Resin until its pH value is between 2.5-3 to obtain acidic cation exchange resin.

[0039] Then the concentration is 32%, the particle diameter is 47nm, the alkaline silica sol 536g that metal ion content is higher than 100ppm joins in the above-mentioned acidic cation exchange resin of 800ml under the situation of continuous stirring, exchange 30min under the situation of stirring, measure simultaneously Exchange the Zeta potential of the solution so that its absolute value is above 40mv, then stop stirring, leave to stand for stratification, and discharge to obtain acidic silica sol.

[0040] Then get 1000ml, 5% sodium hydroxide solution and inject in t...

Embodiment 3

[0044] Inject 1325ml, 10% hydrochloric acid solution into an ion exchange column equipped with 2000ml German Lewatit-100 cation exchange resin for stirring. After stirring for 10 minutes, let it stand for stratification, remove the upper layer solution, and rinse the remaining cation exchange resin with deionized water. Resin until its pH value is between 3-3.5 to obtain acidic cation exchange resin.

[0045] Then the concentration is 42%, the particle diameter is 60nm, the alkaline silica sol 536g that metal ion content is higher than 100ppm joins in the above-mentioned acidic cation exchange resin of 1000ml under the situation of continuous stirring, exchange 60min under the situation of stirring, measure simultaneously Exchange the Zeta potential of the solution so that its absolute value is above 60mV, then stop stirring, leave to stand for stratification, and discharge to obtain acidic silica sol.

[0046] Then get 625ml, 10% sodium hydroxide solution and inject in the io...

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Abstract

This invention discloses a method for purifying silica nanosol used for large-scale integrated circuit. The method comprises: (1) adding hydrochloric acid to a cation exchange resin, and stirring to obtain acidic cation exchange resin; (2) adding basic silica nanosol with a high content of metal ions to the acidic cation exchange resin, and ion-exchanging to obtain acidic silica nanosol; (3) adding NaOH solution to an anion exchange resin, and stirring to obtain basic anion exchange resin; (4) adding acidic silica nanosol to the basic anion exchange resin, and ion-exchanging to obtain basic silica nanosol; (5) adding the basic silica nanosol to the acidic cation exchange resin, and ion-exchanging to obtain acidic silica nanosol with a low content of metal ions. The method has such advantages as high product purity, low equipment cost, and short purification time.

Description

technical field [0001] The invention belongs to a method for purifying nano-abrasives, in particular to a method for purifying silica sol used for CMP special grinding and polishing in the field of microelectronic processing. Background technique [0002] With the development of large-scale integrated circuits, the continuous improvement of integration and the continuous reduction of line width, high density, thin lines, and shallow junctions in the development of integrated circuit technology have become the mainstream. If the surface of the silicon substrate is contaminated by harmful heavy metal impurities during processing, it will affect the interface state of the device and increase the static power consumption current of the device. SiO 2 Reduced dielectric breakdown strength, weakened antistatic ability, threshold voltage drift, early failure of device power aging, especially in sensitive devices such as CMOS and CCD, can also lead to weakened anti-nuclear radiation ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/158C09G1/02
Inventor 刘玉岭王娟张建新
Owner HEBEI UNIV OF TECH
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