CN104164237A

CN104164237A - Silicon dioxide etching solution and preparation method thereof

Info

Publication number: CN104164237A
Application number: CN201310180562.4A
Authority: CN
Inventors: 殷福华; 朱龙; 邵勇
Original assignee: Jiangyin Jianghua Microelectronic Material Co Ltd
Current assignee: Jiangyin Jianghua Microelectronic Material Co Ltd
Priority date: 2013-05-16
Filing date: 2013-05-16
Publication date: 2014-11-26

Abstract

The invention discloses a silicon dioxide etching solution and a preparation method thereof. The silicon dioxide etching solution comprises the following compositions by weight: 20%-30% of an ammonium fluoride solution, 3%-6% of hydrofluoric acid, and the balance ultrapure water. The preparation method of the silicon dioxide etching solution provided by the invention includes: weighing certain amount of an ammonium fluoride solution, adding hydrofluoric acid under stirring, fully stirring the mixture for 15min; then adding the ultrapure water, and conducting stirring for 45min; and then filtering the prepared mixture by a 0.5micrometer filter to remove harmful particles with a particle size larger than 0.5micrometer from the mixture, thus obtaining the silicon dioxide etching solution. Through precise blending, impurities are removed from the etching solution product provided by the invention, the etching precision is high, and the speed is fast.

Description

A kind of SiO 2 etch liquid and preparation method thereof

Technical field

The present invention relates to a kind of etching solution and preparation method thereof, relate in particular to a kind of SiO 2 etch liquid and preparation method thereof.

Background technology

Electronic chemical product generally refers to as the supporting specialty chemicals of electronic industry, and ultra-pure wet electronic chemical product mainly comprises unicircuit and chemical for discrete device, crystal silicon solar by chemical and flat pannel display with chemical etc., its have specification of quality high, functional strong, to producing and the requirement of environment for use cleanliness factor is high and product is more consummate., there are a lot of defects in existing SiO 2 etch liquid, as slow in etching speed, precision is low, can not meet customer need.

Summary of the invention

The invention provides a kind of SiO 2 etch liquid and preparation method thereof, can improve etching speed and precision, meet different clients' demand, comprise the composition of following weight percent: ammonium fluoride solution 20%～30%, hydrofluoric acid 3%～6%, surplus is ultrapure water.

Above-mentioned SiO 2 etch liquid, wherein, the concentration of described ammonium fluoride solution is 40% (weight percent).

Above-mentioned SiO 2 etch liquid, wherein, the concentration of described hydrofluoric acid is 49% (weight percent).

The present invention also provides a kind of preparation method of SiO 2 etch liquid, comprises the steps: to take a certain amount of ammonium fluoride solution, under agitation adds hydrofluoric acid, fully stirs 15 minutes; Then add ultrapure water, stir 45 minutes;

Wherein the weight percent of Neutral ammonium fluoride is 20%～30%, and the weight percent of hydrofluoric acid is 3%～6%, and surplus is water;

Then by the mixture making, the strainer through 0.5 μ m filters, and is greater than harmful particle of 0.5 μ m to remove particle diameter in mixture, obtains SiO 2 etch liquid.

A kind of etching solution provided by the invention is mixed through precision, and the impurity in product is removed in the operations such as filtration, and etching precision is high, and speed is fast, meets the production technique of great scale integrated circuit completely.

Embodiment

Below by embodiment, describe the present invention, but be not limited to illustrated embodiment.

(1), by electronic-grade nitric acid electrically heated rectifying, temperature is controlled at 110 ℃ ± 10 ℃;

(2) step (1) products therefrom is removed to the nitrogen peroxide in cut by blowing white reactor with nitrogen, make its clear, colorless;

(3) step (2) products therefrom is put into the tank that is mixed, add appropriate ultrapure water, stir 30 minutes;

(4) by step (3) products therefrom, the strainer by 0.2 μ m filters, and is greater than harmful particle of 0.2 μ m to remove particle diameter in mixture, obtains this ultra-high pure nitric acid;

The preparation method of above-mentioned a kind of ultra-high pure nitric acid, wherein: in described step (1), nitric acid relative density is 1.40～1.42.

In described step (3), concentration of nitric acid is controlled at 65 ± 0.5%.

The invention provides a kind of preparation method of ultra-high pure nitric acid, the ultra-high pure nitric acid impurity that adopts aforesaid way to make is few, and the nitric acid that purity is high, can reach PPT grade, meets the production technique of great scale integrated circuit completely.

Claims

1. a SiO 2 etch liquid, is characterized in that, comprises the composition of following weight percent: ammonium fluoride solution 20%～30%, and hydrofluoric acid 3%～6%, surplus is ultrapure water.

2. a kind of SiO 2 etch liquid according to claim 1, is characterized in that, the concentration of described ammonium fluoride solution is 40% (weight percent).

3. a kind of SiO 2 etch liquid according to claim 1, is characterized in that, the concentration of described hydrofluoric acid is 49% (weight percent).

4. the preparation method of a kind of SiO 2 etch liquid according to claim 1, is characterized in that, comprises the steps:

(1) take a certain amount of ammonium fluoride solution, under agitation add hydrofluoric acid, fully stir 15 minutes; Then add ultrapure water, stir 45 minutes; Wherein the weight percent of Neutral ammonium fluoride is 20%～30%, and the weight percent of hydrofluoric acid is 3%～6%, and surplus is water;

(2) mixture making is filtered through the strainer of 0.5 μ m, to remove particle diameter in mixture, be greater than harmful particle of 0.5 μ m, obtain SiO 2 etch liquid.