CN108863093B

CN108863093B - Method for controlling fused quartz static acid etching sediment

Info

Publication number: CN108863093B
Application number: CN201810798186.8A
Authority: CN
Inventors: 杨科; 严鸿维; 刘太祥; 晏良宏; 陈静; 贾宝申; 李合阳; 张卓; 黄贝聪; 吕海兵; 蒋晓东
Original assignee: Laser Fusion Research Center China Academy of Engineering Physics
Current assignee: Laser Fusion Research Center China Academy of Engineering Physics
Priority date: 2018-07-19
Filing date: 2018-07-19
Publication date: 2021-06-08
Anticipated expiration: 2038-07-19
Also published as: CN108863093A

Abstract

The invention discloses a method for controlling static acid etching sediment of fused quartz, which utilizes the concentration diffusion of hexafluorosilicate in the short-time acid etching process, sprays and ultrasonically cleans a fused quartz element to remove residual ions after acid etching, and repeats the processes of acid etching, spraying and ultrasonic rinsing for many times to realize the etching of the fused quartz with a certain depth, thereby not only avoiding the appearance of the sediment, keeping the surface shape, but also improving the laser damage threshold value, realizing the effective and complete removal of a fused quartz polishing layer and a defect layer, and having no sediment; the method has the advantages of simple operation, controllability, no damage to the surface shape and roughness of the optical element, economy and the like.

Description

Method for controlling fused quartz static acid etching sediment

Technical Field

The invention belongs to the technical field of optical materials and optical elements, and particularly discloses a method for controlling fused quartz static acid etching deposits.

Background

The fused quartz transmission element used by the large-scale high-power solid laser device has high requirements on surface shape indexes and laser damage thresholds. The fused silica component obtained by the traditional processing method contains polishing layer impurities, embedded pollutants, subsurface defects (including microcracks, pits and the like), and in order to improve the laser damage threshold, the impurities must be removedQuality and defects, the most effective means at present is to etch the component with a hydrofluoric acid containing solution. The acid etching solution mainly comprises two solutions, one is hydrofluoric acid solution, and the other is NH-containing solution₄Buffered hydrofluoric acid (BHF) solution of F, also known as BOE solution. The latter is usually chosen during the etching of fused silica because the latter etch rate is very stable, the surface of the fused silica is etched more smoothly after etching than with pure hydrofluoric acid solution, and the HF content in the buffered hydrofluoric acid solution is low (meaning less volatile and toxic) with the same etch rate. But it is due to NH during the etching process₄ ⁺The cation content is high, and the cation is easy to combine with hexafluorosilicate ions which are reaction products to generate precipitates (sediments), so that the surface shape of the surface of the fused quartz element is damaged, and the laser damage resistance threshold of the fused quartz element is greatly reduced.

Conventionally processed fused silica components typically require etching of at least a few microns to reduce the subsurface defect density to a certain degree. The deposition from long static etch results in a threshold drop. To reduce the deposits resulting from prolonged etching, it has proven effective to introduce ultrasound or megasonic waves into the reaction. The use of megasonic/ultrasonic waves in hydrofluoric acid presents the following technical challenges: 1) uneven etching caused by the temperature rise effect of an etching solution caused by a sound field, 2) hydrofluoric acid corrosion resistance of a vibrating plate coating material, 3) circular filtration in the cleaning reaction process, and 4) megasonic waves generate standing wave fields, interference, turbulence and other problems, so that local etching is too fast to cause surface shape deterioration or local area transportation is too slow to cause deposition of deposits, the cost is greatly improved, and an etched element cannot meet the requirement of an optical index. Without ultrasonic and megasonic etching, i.e., static etching, short duration etching had no effect on the profile, but long duration etching resulted in a drop in threshold and the formation of surface deposits, as shown in figure 1. Therefore, the key point is to reduce the generation of surface deposits on the premise of accurately controlling the etching process and ensuring the etching depth of the element.

Disclosure of Invention

An object of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.

The invention provides a method for preventing the generation of sediment by combining multiple short-time (accumulated etching time and etching with a certain depth) static acid etching with an ultrasonic high-purity water cleaning method, greatly improving the laser damage resistance of a fused quartz element, reducing the unevenness of surface etching and the maintenance of surface shape, and being capable of aiming at large-caliber optical elements.

To achieve these objects and other advantages in accordance with the purpose of the invention, a method for controlling fused silica static acid etch deposits is provided, comprising the steps of:

step one, putting fused quartz into a buffered hydrofluoric acid etching solution, wherein the temperature is 23 +/-1 ℃, the single reaction etching time is less than 20min, and the average etching rate is 1.5-2 mu m/h;

step two, carrying out high-purity water spraying rinsing on the fused quartz etched in the step one, wherein the spraying pressure is not less than 0.2Mpa, the temperature is 30 +/-2 ℃, the flow is 120L/min, the time is not less than 10min, and removing redundant acid liquid on the surface and a large amount of SiF₆ ^2-；

Step three, putting the rinsed fused quartz in the step two into a tank filled with high-purity water for ultrasonic rinsing, wherein the temperature is 35 ℃, the ultrasonic power density is not less than 5W/L, the 220KHz ultrasonic cleaning is carried out for more than 15min, the 270KHz ultrasonic cleaning is carried out for more than 15min, the total ultrasonic cleaning is not less than 30min, and further removing SiF₆ ^2-Ions;

step four, putting the rinsed fused quartz in the step three into a tank filled with high-purity water, slowly pulling the fused quartz at the temperature of 55 +/-2 ℃, the ultrasonic frequency of 270KHz and the ultrasonic power density of not less than 5W/L to remove the redundant water on the surface of the optical element;

rotating the fused quartz clockwise by 90 degrees, ultrasonically cleaning the tank body for draining water, adding high-purity water again and heating to a corresponding temperature;

step six, repeating the step one to the step five, wherein the etching time of each time in the step one is the same, and the etching times are multiples of 4, namely 4 times of etching of the fused quartz are combined into one group, and at least 1 time of etching is carried out; until the etching depth is more than 4 μm.

Preferably, the high purity water has a resistivity >15M Ω.

Preferably, the slow pull in the fourth step has a pull rate of 1 mm/s.

Preferably, the mass fraction of hydrofluoric acid in the buffered hydrofluoric acid etching solution is 0.8-1.2%, and NH₄F and NH₄C₂H₄NH₄F₂The mass fraction of (A) is 8-12%.

Preferably, in the step one, the reaction etching time is 15 min; the average etching rate was 1.8. mu.m/h.

Preferably, in the second step, the spraying pressure is 0.5-1.5 Mpa; the time is 15 min.

Preferably, in the third step, the ultrasonic power density is 10W/L, the ultrasonic cleaning is carried out for 20min at 220KHz, and the cleaning is carried out for 20min at 270 KHz; in the fourth step, the ultrasonic power density is 10W/L.

Preferably, in the step one, nano bubbles are introduced into the buffered hydrofluoric acid etching solution in the reaction etching process; the nano bubbles are any one or a combination of more of oxygen, ozone, nitrogen, argon or carbon dioxide; the diameter of the nano bubbles is 0.1-100 um; the aeration rate of the nano bubbles is 50-100 mL/min.

Preferably, the following process is further included before the step one: putting the fused quartz into a supercritical device, and soaking for 5-10 min in a supercritical acetone-water system with the temperature of 350-370 ℃ and the pressure of 8-14 MPa; the volume ratio of acetone to water in the supercritical acetone-water system is 5: 1.

Preferably, the method further comprises the following steps after soaking in a supercritical acetone-water system: feeding the fused quartz into an atmospheric pressure low-temperature plasma device, enabling the fused quartz to be located at a spraying outlet of the atmospheric pressure low-temperature plasma for 50-100 mm, and enabling the spraying outlet of the fused quartz to rotate at a rotating speed of 30-60 r/min; introducing gas into an atmospheric pressure low-temperature plasma device according to the gas flow of 5-15L/h, applying working voltage to form plasma jet, controlling the moving speed of a jet outlet of the atmospheric pressure low-temperature plasma device to be 5-10 mm/s, jetting the plasma jet on the rotating fused quartz, and treating the fused quartz for 5-10 min; the working voltage is provided by a high-voltage alternating current power supply, the working voltage is 35-100 kV alternating current voltage, and the frequency is 100-300 kHz; the gas is one or a mixture of air, rare gas/oxygen, oxygen and nitrogen.

The invention at least comprises the following beneficial effects: according to the method, the diffusion of hexafluorosilicate in the acid etching process is utilized, the fused quartz element is sprayed and ultrasonically cleaned within a certain time to remove residual ions, and the process is repeated for multiple times, so that the etching of the fused quartz with a certain depth is realized, the occurrence of deposits is avoided, the surface shape is kept, and the laser damage threshold is improved; the method realizes effective and complete removal of the fused quartz polishing layer and the defect layer without generating deposits, and has the advantages of simple operation, economy, controllability, no damage to the surface shape and roughness of the optical element and the like.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Description of the drawings:

FIG. 1 is a graph showing the relationship between the etching time of the short-time dynamic multiple acid etching and the laser damage threshold (wavelength 355nm, pulse width 3 ns);

FIG. 2 is a photomicrograph of a fused silica of the present invention subjected to a short dynamic multiple acid etch;

FIG. 3 is a dark field photograph of long duration static acid etched fused silica of comparative example 1;

FIG. 4 is an atomic force microscope photomicrograph of long-term static acid etched fused silica of comparative example 1;

FIG. 5 is a schematic diagram showing the ion concentration variation of the reaction product of a single acid etching process;

FIG. 6 is a schematic diagram showing the variation of ion concentration of reaction products in a spray rinsing process;

FIG. 7 is a schematic diagram showing the change of ion concentration of reaction products in the ultrasonic rinsing process.

The specific implementation mode is as follows:

the present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

Example 1:

a method of controlling fused silica static acid etch deposits comprising the steps of:

step one, putting 50mm multiplied by 5mm fused quartz into a buffered hydrofluoric acid etching solution, wherein the temperature is 23 ℃, the single reaction etching time is 15min, and the average etching rate is 1.5 mu m/h;

step two, carrying out high-purity water spraying rinsing on the fused quartz etched in the step one, wherein the spraying pressure is 0.5Mpa, the temperature is 30 ℃, the flow rate is 120L/min, the time is 15min, and removing redundant acid liquor and a large amount of SiF on the surface₆ ^2-；

Step three, putting the rinsed fused quartz in the step two into a tank filled with high-purity water for ultrasonic rinsing, wherein the temperature is 35 ℃, the ultrasonic power density is 10W/L, the ultrasonic cleaning is carried out for 20min at 220KHz, the ultrasonic cleaning is carried out for 20min at 270KHz, and SiF is further removed₆ ^2-Ions;

step four, putting the rinsed fused quartz in the step three into a tank filled with high-purity water, slowly pulling at the temperature of 55 ℃, the ultrasonic frequency of 270KHz, the ultrasonic power density of 10W/L and the speed of 1mm/s, and removing redundant water on the surface of the optical element;

step six, repeating the step one to the step five, wherein each etching time in the step one is the same, and the etching times are multiples of 4, namely 4 times of fused quartz etching are combined into one group (1 time of etching is carried out after the step one to the step four are finished, then the next time of etching is carried out by clockwise rotation of 90 degrees, and the 4 times of etching is combined into 1 group), and etching 1 group to reduce the influence on the surface shape caused by uneven diffusion due to different depths; until the etching depth is 4 μm;

resistivity of the high purity water>15M omega cm; the mass fraction of hydrofluoric acid in the buffer hydrofluoric acid etching liquid is 0.8 percent, and NH is₄F and NH₄C₂H₄NH₄F₂8% by mass of (A).

Example 2:

step one, putting 50mm multiplied by 5mm fused quartz into a buffered hydrofluoric acid etching solution, wherein the temperature is 24 ℃, the single reaction etching time is 20min, and the average etching rate is 2 mu m/h;

step two, carrying out high-purity water spraying rinsing on the fused quartz etched in the step one, wherein the spraying pressure is 0.6Mpa, the temperature is 32 ℃, the flow rate is 120L/min, the time is 20min, and removing redundant acid liquor and a large amount of SiF on the surface₆ ^2-；

Step three, putting the rinsed fused quartz in the step two into a tank filled with high-purity water for ultrasonic rinsing, wherein the temperature is 35 ℃, the ultrasonic power density is 10W/L, the ultrasonic cleaning is carried out for 25min at 220KHz, the ultrasonic cleaning is carried out for 25min at 270KHz, and SiF is further removed₆ ^2-Ions;

step four, putting the rinsed fused quartz in the step three into a tank filled with high-purity water, slowly pulling at the temperature of 55 ℃, the ultrasonic frequency of 270KHz, the ultrasonic power density of 12W/L and the speed of 1mm/s, and removing redundant water on the surface of the optical element;

step six, repeating the step one to the step five, wherein the etching time of each time in the step one is the same, and the etching times are multiples of 4, namely 4 times of fused quartz etching are used as one group, and 2 groups of fused quartz etching are used, so that the influence on the surface shape caused by the uneven diffusion due to different depths is reduced; until the etching depth is 5 μm;

resistivity of the high purity water>15M omega cm; the mass fraction of hydrofluoric acid in the buffer hydrofluoric acid etching liquid is 1.2%, and NH₄F and NH₄C₂H₄NH₄F₂12% by mass.

Example 3:

step one, putting the fused quartz with the thickness of 430mm multiplied by 20mm into a buffered hydrofluoric acid etching solution, wherein the temperature is 24 ℃, the single reaction etching time is 20min, and the average etching rate is 1.8 mu m/h;

step two, carrying out high-purity water spraying rinsing on the fused quartz etched in the step one, wherein the spraying pressure is 0.6Mpa, the temperature is 32 ℃, the flow rate is 120L/min, the time is 18min, and removing redundant acid liquor and a large amount of SiF on the surface₆ ^2-；

Step three, putting the rinsed fused quartz in the step two into a tank filled with high-purity water for ultrasonic rinsing, wherein the temperature is 35 ℃, the ultrasonic power density is 12W/L, the ultrasonic cleaning is carried out for 25min at 220KHz, the cleaning is carried out for 20min at 270KHz, and SiF is further removed₆ ^2-Ions;

step four, putting the rinsed fused quartz in the step three into a tank filled with high-purity water, slowly pulling at the temperature of 57 ℃, the ultrasonic frequency of 270KHz, the ultrasonic power density of 12W/L and the speed of 1mm/s, and removing redundant water on the surface of the optical element;

subjecting the treated fused quartz to 351nm wavelength laser, with pulse width of 5ns and light transmission area of 1150cm²Average flux of 5.97J/cm²In total, 50 tests were performed, and 5 damage points appeared on the surface, whichMiddle 3 d>120um lesions, 2 50um lesions. The surface shape change and the damage before and after etching are shown in fig. 5 and table 1.

Resistivity of the high purity water>15M omega cm; the mass fraction of hydrofluoric acid in the buffer hydrofluoric acid etching liquid is 1 percent, and NH₄F and NH₄C₂H₄NH₄F₂Is 10% by mass.

Example 4:

in the first step, nano bubbles are introduced into the buffered hydrofluoric acid etching solution in the reaction etching process; the nano bubbles are oxygen; the diameter of the nano bubbles is 0.1 um; the aeration rate of the nanobubbles was 50 mL/min. By adopting the process, the polishing layer and the defect layer of the fused quartz are effectively removed, and the surface roughness of the fused quartz after etching is further reduced.

The remaining process parameters and procedures were exactly the same as in example 1.

Example 5:

in the first step, nano bubbles are introduced into the buffered hydrofluoric acid etching solution in the reaction etching process; the nano bubbles are ozone; the diameter of the nano bubbles is 0.2 um; the aeration rate of the nanobubbles was 80 mL/min.

The remaining process parameters and procedures were exactly the same as in example 3.

Example 6:

the following processes are further included before the step one: putting the fused quartz into a supercritical device, and soaking for 10min in a supercritical acetone-water system with the temperature of 360 ℃ and the pressure of 12 MPa; the volume ratio of acetone to water in the supercritical acetone-water system is 5: 1. By adopting the treatment process, the pretreatment of the fused quartz is realized, the structural defects of the fused quartz are eliminated, and the surface roughness of the fused quartz after etching is further reduced.

Example 7:

the following processes are further included before the step one: putting the fused quartz into a supercritical device, and soaking for 10min in a supercritical acetone-water system with the temperature of 360 ℃ and the pressure of 12 MPa; the volume ratio of acetone to water in the supercritical acetone-water system is 5: 1.

Example 8:

the method also comprises the following steps after soaking in a supercritical acetone-water system: delivering the fused quartz into an atmospheric pressure low-temperature plasma device, enabling the fused quartz to be positioned at a jet outlet of the atmospheric pressure low-temperature plasma for 100mm, and enabling the jet outlet of the fused quartz to rotate at a rotating speed of 60 r/min; introducing gas into an atmospheric pressure low-temperature plasma device according to the gas flow of 15L/h, applying working voltage to form plasma jet, controlling the moving speed of a jet outlet of the atmospheric pressure low-temperature plasma device to be 10mm/s, jetting the plasma jet on the rotating fused quartz, and treating the fused quartz for 5 min; the working voltage is provided by a high-voltage alternating current power supply, the working voltage is 100kV alternating current voltage, and the frequency is 200 kHz; the gas is the mixture of air and ammonia gas; by adopting the process, the pretreatment of the fused quartz is realized, the structural defect of the fused quartz is eliminated, the polishing layer and the defect layer of the fused quartz are further effectively removed, and the surface roughness of the fused quartz after etching is further reduced.

The remaining process parameters and procedures were exactly the same as in example 6.

Example 9:

the method also comprises the following steps after soaking in a supercritical acetone-water system: feeding the fused quartz into an atmospheric pressure low-temperature plasma device, enabling the fused quartz to be located at a spraying outlet of the atmospheric pressure low-temperature plasma for 50mm, and enabling the spraying outlet of the fused quartz to rotate at a rotating speed of 45 r/min; introducing gas into an atmospheric pressure low-temperature plasma device according to the gas flow of 12L/h, applying working voltage to form plasma jet, controlling the moving speed of a jet outlet of the atmospheric pressure low-temperature plasma device to be 10mm/s, jetting the plasma jet on the rotating fused quartz, and treating the fused quartz for 8 min; the working voltage is provided by a high-voltage alternating current power supply, the working voltage is 85kV alternating current voltage, and the frequency is 150 kHz; the gas is a mixture of oxygen and ammonia.

The remaining process parameters and procedures were exactly the same as in example 7.

Example 10:

The remaining process parameters and procedures were exactly the same as in example 9.

Comparative example 1:

step one, putting 50mm multiplied by 5mm fused quartz into a buffered hydrofluoric acid etching solution, wherein the temperature is 23 ℃, the reaction etching time is 60min, and the average etching rate is 1.5 mu m/h; until the etching depth is 4 μm;

step two, carrying out high-purity water spraying rinsing on the fused quartz etched in the step one, wherein the spraying pressure is 0.5Mpa, the temperature is 30 ℃, the flow rate is 120L/min, the time is 60min, and removing redundant acid liquor and a large amount of SiF on the surface₆ ^2-；

Step three, putting the rinsed fused quartz in the step two into a tank filled with high-purity water for ultrasonic rinsing, wherein the temperature is 35 ℃, the ultrasonic power density is 10W/L, the ultrasonic cleaning is carried out for 80min at 220KHz, the ultrasonic cleaning is carried out for 80min at 270KHz, and SiF is further removed₆ ^2-Ions;

and step four, putting the rinsed fused quartz in the step three into a tank filled with high-purity water, slowly pulling at the temperature of 55 ℃, the ultrasonic frequency of 270KHz, the ultrasonic power density of 10W/L and the speed of 1mm/s, and removing the redundant water on the surface of the optical element.

Example 1 compared to comparative example 1, a single etch for a longer period of time (1 etch, 60min) in comparative example 1 resulted in a deterioration of the profile and in the formation of surface deposits (see fig. 3 photomicrograph and fig. 4 atomic force microscope)Shown in a mirror image), but 4 times of etching with a single etching time of 15min in example 1 not only improves the laser damage threshold, but also reduces the deterioration of the surface shape and controls the deposit on the surface, as shown in fig. 1-2; wherein, as can be seen from FIG. 1, the laser damage resistance threshold of the pre-etched fused silica is 12J/cm²Generally, the depth of the sub-surface defect layer to be removed is at least 2 μm (the etching rate process requires at least 60min, the worse the processing quality, the corresponding increase of the etching depth), it can be seen that the threshold value is increased with the increase of the etching time, but if the single acid etching time is too long, as shown in the figure, from 105min to 135min, from 135min to 165min, the single acid etching time is 30min, which causes the laser damage threshold value to be reduced, and according to a plurality of experiments, the single acid etching time is determined to be not more than 20min, otherwise, the laser damage threshold value is reduced.

FIG. 5 is a schematic diagram showing the ion concentration variation of the reaction product of a single acid etching process; the ion concentration of the reaction product is gradually increased along with the etching;

FIG. 6 is a schematic diagram showing the variation of ion concentration of reaction products in a spray rinsing process; the ion concentration of the reaction product is gradually reduced along with the spray rinsing;

FIG. 7 is a schematic diagram showing the change of ion concentration of reaction products in the ultrasonic rinsing process; the ion concentration of the reaction product gradually decreases as the ultrasonic rinsing is performed.

Wherein, table 1 shows the relevant indexes after the fused quartz is etched in the embodiments 1-10; before etching of fused quartz: PV (λ 632.8nm) is 0.674; surface roughness rq (nm) (a-plane) 0.604; surface roughness rq (nm) (B-plane) 0.598;

TABLE 1

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims

1. A method of controlling fused silica static acid etch deposition comprising the steps of:

step six, repeating the step one to the step five, wherein the etching time of each time in the step one is the same, and the etching times are multiples of 4, namely 4 times of etching of the fused quartz are combined into one group, and at least 1 time of etching is carried out; until the etching depth is more than 4 μm;

the mass fraction of hydrofluoric acid in the buffer hydrofluoric acid etching liquid is 0.8-1.2%, and NH₄F and NH₄C₂H₄NH₄F₂8-12% of the total mass;

in the first step, nano bubbles are introduced into the buffered hydrofluoric acid etching solution in the reaction etching process; the nano bubbles are any one or a combination of more of oxygen, ozone, nitrogen, argon or carbon dioxide; the diameter of the nano bubbles is 0.1-100 um; the aeration rate of the nano bubbles is 50-100 mL/min;

the following processes are further included before the step one: putting the fused quartz into a supercritical device, and soaking for 5-10 min in a supercritical acetone-water system with the temperature of 350-370 ℃ and the pressure of 8-14 MPa; the volume ratio of acetone to water in the supercritical acetone-water system is 5: 1.

2. The method of controlling fused silica static acid etch deposits according to claim 1, wherein said high purity water has a resistivity of >15M Ω.

3. The method for controlling the static acid etching deposition of fused silica as claimed in claim 1, wherein the slow pull in the fourth step has a pull rate of 1 mm/s.

4. The method for controlling the static acid etching deposition of fused silica as claimed in claim 1, wherein in the first step, the reaction etching time is 15 min; the average etching rate was 1.8. mu.m/h.

5. The method for controlling the static acid etching deposition of fused quartz according to claim 1, wherein in the second step, the spraying pressure is 0.5-1.5 Mpa; the time is 15 min.

6. The method for controlling fused silica static acid etch deposits according to claim 1, wherein in the third step, the ultrasonic power density is 10W/L, the 220KHz ultrasonic cleaning is 20min, and the 270KHz cleaning is 20 min; in the fourth step, the ultrasonic power density is 10W/L.

7. The method of claim 1, further comprising, after soaking in a supercritical acetone-water system: feeding the fused quartz into an atmospheric pressure low-temperature plasma device, enabling the fused quartz to be located at a spraying outlet of the atmospheric pressure low-temperature plasma for 50-100 mm, and enabling the spraying outlet of the fused quartz to rotate at a rotating speed of 30-60 r/min; introducing gas into an atmospheric pressure low-temperature plasma device according to the gas flow of 5-15L/h, applying working voltage to form plasma jet, controlling the moving speed of a jet outlet of the atmospheric pressure low-temperature plasma device to be 5-10 mm/s, jetting the plasma jet on the rotating fused quartz, and treating the fused quartz for 5-10 min; the working voltage is provided by a high-voltage alternating current power supply, the working voltage is 35-100 kV alternating current voltage, and the frequency is 100-300 kHz; the gas is one or a mixture of air, oxygen and nitrogen.