Manufacturing process of reaction equipment coating for producing semiconductor-grade high-purity quartz sand

Abstract

The invention provides a manufacturing process of a reaction equipment coating for producing semiconductor-grade high-purity quartz sand. Raw powder is obtained by taking silicon dioxide as a main material, sodium oxide and calcium oxide as fluxing materials and adding a proper amount of stabilizing agents such as aluminum oxide, boric oxide, magnesium oxide and zinc oxide through high-temperature sintering and water hammer crushing. And placing for more than 15 days after multiple spraying, high-temperature sintering and other procedures, and pickling with nitric acid. And when the prepared equipment coating is used for producing a semiconductor-grade silicon dioxide product, the product pollution caused by the coating is avoided, and the product index is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of special reactors for the production of high-purity semiconductor-grade silica, and specifically to a manufacturing process for the coating of reaction equipment for producing semiconductor-grade high-purity quartz sand. Background Art

[0002] With the development of semiconductor technology, the requirements for semiconductor materials are getting higher and higher. As the standards for semiconductor materials gradually increase, higher requirements are imposed on the equipment for producing these semiconductor materials. This is because, during the production of semiconductor materials, the materials of these contacting equipment itself will contaminate the produced products, making our semiconductor materials fail to meet our requirements. In order to make semiconductor materials reach and exceed the international level, we must design higher-level production equipment.

[0003] Semiconductor-grade silica is a very important material in semiconductor manufacturing, and its quality requirements are very high. Semiconductor-grade silica needs to undergo special treatment processes to remove impurities and particles.

[0004] And it is required that the purity, crystal structure, impurity content, surface roughness, etc. of semiconductor-grade silica all reach very high standards.

[0005] In order to stably produce semiconductor-grade high-standard silica, we have developed a protective coating specifically for semiconductor-grade silica production equipment. Summary of the Invention

[0006] To solve the problems in the production of high-purity silica, we have designed a material to protect and isolate the equipment for producing silica precursors.

[0007] The present invention consists of two parts. The first part is the preparation of the isolation material raw materials, and the second part is the sintering of the isolation material.

[0008] Manufacture of the special isolation coating:

[0009] Ingredient preparation: Take 72 - 75 parts of silica (content 99.9%), 11 - 14 parts of potassium carbonate (content 99%), 18.5 - 24 parts of calcium carbonate (content 99%), and the remaining 2.5 - 2.8 parts are structural stabilizers. The stabilizers include one or several of boron oxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, titanium oxide, and antimony oxide.

[0010] Preferably, boron oxide is 3 - 5%, aluminum oxide is 1 - 1.6%, and zinc oxide is 0.1 - 0.3%.

[0011] Mix the main raw materials such as silica, potassium carbonate, and calcium oxide, as well as some of the stabilizers evenly.

[0012] Sinter the above-mentioned well-mixed materials by heating them up according to a program.

[0013] The calcination temperature is raised to 1100 ± 20 °C at a heating rate of 5 - 10 °C / min, and the heating rate is preferably 8 - 9 °C / min.

[0014] Add the prepared ingredients, keep them at a constant temperature for one hour, then heat them up at a rate of 2 - 5 °C / min, preferably 2 - 3 °C / min, to 1300 °C, and keep them at a constant temperature for two hours.

[0015] Then heat them up to 1450 °C at a rate of 1 - 3 °C / min and keep them at a constant temperature for two hours.

[0016] Take out the above-mentioned fired materials from the calcination furnace. The temperature of the materials should not be lower than 1100 - 1300 °C, preferably 1200 °C.

[0017] Pour the sintered materials into water, and the water impacts them into powdery solids.

[0018] Then centrifuge to obtain the isolation coating powder we need.

[0019] Mix the above-mentioned centrifuged powder with an appropriate amount of silica gel solution to form a flowing paste.

[0020] The solid content of the paste is between 40 - 80%, preferably 55 - 70%.

[0021] Spray the paste evenly inside the reaction vessel.

[0022] The spraying conditions are high-pressure air spraying.

[0023] After spraying, let it dry naturally.

[0024] Put the above-mentioned sprayed equipment into the calcination furnace for calcination.

[0025] The calcination temperature is raised at a heating rate of 1 - 6 °C / min, preferably 2 - 3 °C / min, to 300 ± 5 °C, and keep it at a constant temperature for one hour.

[0026] Then heat it up at a rate of 1 - 5 °C / min to 700 °C and keep it at a constant temperature for two hours.

[0027] Then heat it up to 850 °C at a rate of 1 - 3 °C / min and keep it at a constant temperature for 1 h.

[0028] Cool down the sintered coating according to a program.

[0029] The cooling program is to cool down from 850 °C to 300 °C at a cooling rate of 1 - 2 °C / min and keep it at 300 °C for 2 h.

[0030] Cool down from 300 °C to 100 °C at a rate of 2 - 3 °C / min to 60 °C.

[0031] Repeat the spraying, sintering, and cooling steps 3 - 8 times until the requirements are met. Preferably 4 - 5 times.

[0032] The thickness of the coating is 0.8 - 2.5 mm, preferably 1.2 - 1.6 mm.

[0033] The acid used for pickling and passivating the equipment is strong acid such as hydrochloric acid, perchloric acid, and nitric acid.

[0034] Preferably nitric acid.

[0035] The acidity for immersion washing is 2 - 10%, preferably the concentration is 5 - 6%.

[0036] The temperature for acid immersion is 40 - 80 °C, preferably 50 - 60 °C.

[0037] The immersion time is 2 - 6 h, preferably 4 - 5 h. Description of the Drawings

[0038] Figure 1 It is a process flow chart for manufacturing the coating of a reaction equipment for producing semiconductor - grade high - purity quartz sand. Detailed Embodiments

[0039] In order to make the objectives, technical solutions, and advantages of the present invention more obvious, the following examples are combined to further elaborate on the present invention. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] Example 1

[0041] A formulation for the protective coating of a quartz sand production equipment

[0042] Main materials: 75 parts of silicon dioxide (content 99.9%), 13 parts of potassium carbonate (content 99%), 21 parts of calcium carbonate (content 99%).

[0043] Structure stabilizers: boron oxide = 3%, aluminum oxide 1.2%, zinc oxide 0.18%

[0044] Mix the above materials evenly.

[0045] Heat the calcination furnace to 1100 °C at a heating rate of 8 °C / min, then add the above - prepared formulation, keep it warm for one hour, then heat at 3 °C / min to 1300 °C and keep it warm for two hours. Then heat at 1 °C / min to 1450 °C and keep it warm for two hours. Take out the above - fired material from the calcination furnace, and the temperature of the material is not lower than 1200 °C. Pour it into water, and it will be hit into powdery solid by water. Obtain the powdery isolation coating powder through centrifugation.

[0046] Mix the centrifuged powder with an appropriate amount of silica gel solution to form a flowing paste. The ratio of water to solid is 4:6. Pulp evenly and spray with a high-pressure air spray gun. After spraying, let it dry naturally.

[0047] Put the sprayed equipment into a calcination furnace for calcination. The calcination temperature is increased at a rate of 2 °C / min to 300 °C and held for one hour. Then increase the temperature at a rate of 3 °C / min to 700 °C and hold for two hours. Finally, increase the temperature to 850 °C at a rate of 1 °C / min and hold for 1 h.

[0048] The sintered coating is cooled from 850 °C to 300 °C at a cooling rate of 2 °C / min and held at 300 °C for 2 h. Then it is cooled from 300 °C to 60 °C at a rate of 2 °C / min.

[0049] Repeat the spraying, sintering, and cooling steps 4 times until the thickness of the coating reaches 1.2 mm. Then let it stand for 15 days.

[0050] The equipment is pickled and passivated by soaking in 5% nitric acid. The pickling temperature is 60 °C and the soaking time is 4 h.

[0051] The final product has met the design requirements, and this coating will not add new impurities to the reaction materials during the reaction process.

[0052] Example 2

[0053] Main materials: 71 parts of silicon dioxide (content 99.9%), 16 parts of potassium carbonate (content 99%), 21 parts of calcium carbonate (content 99%).

[0054] Structure stabilizers: boron oxide = 3.5%, alumina 1.6%, zinc oxide 0.2%, zirconium oxide 0.8%.

[0055] Mix the above materials evenly.

[0056] Increase the temperature of the calcination furnace to 1100 °C at a rate of 6 °C / min, then add the above-prepared ingredients, hold for one hour, then increase the temperature at a rate of 2 °C / min to 1300 °C and hold for two hours. Then increase the temperature to 1450 °C at a rate of 1 °C / min and hold for two hours. Take out the above-fired materials from the calcination furnace, and the temperature of the materials is not lower than 1300 °C. Pour them into water, and the water impacts into powdery solids. Obtain powdery isolation coating powder by centrifugation.

[0057] Mix the centrifuged powder with an appropriate amount of silica gel solution to form a flowing paste. The ratio of water to solid is 3:7. Pulp evenly and spray with a high-pressure air spray gun. After spraying, let it dry naturally.

[0058] The sprayed equipment is placed in a calcination furnace for calcination. The calcination temperature is increased at a rate of 2 °C / min to 300 °C and held for one hour. Then it is heated at a rate of 4 °C / min to 700 °C and held for two hours. Finally, it is heated at a rate of 1 °C / min to 850 °C and held for 1 h.

[0059] The sintered coating is cooled from 850 °C to 300 °C at a rate of 1 °C / min and held at 300 °C for 2 h. Then it is cooled from 300 °C to 60 °C at a rate of 3 °C / min.

[0060] The spraying, sintering, and cooling steps are repeated 5 times until the thickness of the coating reaches 1.4 mm. Then it is left for 15 days.

[0061] The equipment is pickled and passivated by soaking in 6% nitric acid. The pickling temperature is 50 °C and the soaking time is 4 h.

[0062] The final product has met the design requirements, and this coating will not add new impurities to the reaction materials during the reaction process.

[0063] Example 3

[0064] Main materials: 73 parts of silicon dioxide (content 99.9%), 14 parts of potassium carbonate (content 99%), 22 parts of calcium carbonate (content 99%).

[0065] Structure stabilizers: boron oxide = 4%, aluminum oxide 1%, zinc oxide 0.2%.

[0066] Mix the above materials evenly.

[0067] Heat the calcination furnace to 1100 °C at a rate of 8 °C / min, then add the above-prepared ingredients, hold for one hour, then heat at a rate of 1.5 °C / min to 1300 °C and hold for two hours. Then heat at a rate of 1 °C / min to 1450 °C and hold for two hours. Take out the above-fired material from the calcination furnace, and the temperature of the material is not lower than 1100 °C. Pour it into water, and it will be beaten into a powdery solid. Obtain the powdery isolation coating powder by centrifugation.

[0068] Mix the above centrifuged powder with an appropriate amount of silica gel solution to form a flowing paste. The ratio of water to solid is 3:7, mix evenly by beating, and spray with a high-pressure air spray gun. After spraying, let it dry naturally.

[0069] The sprayed equipment is placed in a calcination furnace for calcination. The calcination temperature is increased at a rate of 2 °C / min to 300 °C and held for one hour. Then it is heated at a rate of 2 °C / min to 700 °C and held for two hours. Finally, it is heated at a rate of 1 °C / min to 850 °C and held for 1 h.

[0070] The cooling rate of the sintered coating from 850 °C to 300 °C is 2 °C / min, and it is held at 300 °C for 2 h. Then it is cooled from 300 °C to 60 °C at a rate of 2 °C / min.

[0071] The steps of spraying, sintering, and cooling are repeated 4 times until the thickness of the coating reaches 1.6 mm. Then it is left for 15 days.

[0072] The equipment is pickled and passivated by soaking in 5% nitric acid. The pickling temperature is 55 °C and the soaking time is 5 h.

[0073] The final product has been tested and meets the design requirements. This coating will not add new impurities to the reaction materials during the reaction process.

[0074] In the present invention, unless otherwise clearly specified and defined, the first feature being “above” or “below” the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being “above”, “over” and “on top of” the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being “below”, “under” and “beneath” the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature

[0075] The above describes the present invention and its embodiments. This description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design similar structural forms and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand, characterized in that: The following steps are involved: Step 1: Evenly mix the main raw materials including silicon dioxide, potassium carbonate, calcium oxide, and stabilizer; Step 2: heating the mixed materials to sinter them; Step 3: pour the sintered product into cold water for water hammer crushing; Step 4: Mix the above powder with silica gel solution to form a flowing paste; Step 5: spray the paste evenly into the reaction container; Step 6: Sintering according to the secondary sintering procedure; Step 7: Cooling down the sintered coating; Step 8. Repeat steps 5 to 7 three to eight times until the coating thickness is 0.8-2.5mm; Step 9: After sintering, place the coating for more than 15 days, then soak and wash it with dilute acid.

2. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: In step 1, the silicon dioxide content is 70-75%, the potassium oxide content is 8-10%, and the calcium oxide content is 10.5-13.5%; The stabilizer includes one or more of boron oxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, titanium oxide, and antimony oxide.

3. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: In step 2, the calcination temperature is raised to 1100±20°C at a rate of 5-10°C / min, the ingredients are added, and the temperature is kept for one hour; Then, the temperature was raised at 2-5°C / min to 1300°C and kept at that temperature for two hours. Then, the temperature was raised at 1-3°C / min to 1450°C and kept at that temperature for two hours.

4. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: The sintered material in step 3 is poured into water, and the temperature of the material is not lower than 1100-1300°C.

5. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: The solid content of the paste in step 4 is 40-80%.

6. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: In step 5, the spraying condition is air flow high pressure spraying. After spraying, it is left to dry naturally. The spraying thickness of the coating is 0.8-2.5 mm.

7. A process for producing a coating of a reaction device for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: In step six, the calcination temperature is increased to 300±5°C at a rate of 1-6°C / min, kept at this temperature for one hour, then increased to 700°C at a rate of 1-5°C / min, kept at this temperature for two hours, then increased to 850°C at a rate of 1-3°C / min, kept at this temperature for 1 hour.

8. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: In step 7, the temperature is lowered from 850°C to 300°C at a rate of 1-2°C / min, and kept at 300°C for 2h; From 300℃ to 100℃, the temperature drops to 60℃ at a rate of 2-3℃ / min.

9. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 1, characterized in that: In step nine, the acid is any one of hydrochloric acid, perchloric acid and nitric acid; the acidity of the immersion washing is 2-10%.

10. A process for producing a coating of a reaction equipment for producing semiconductor-grade high-purity quartz sand as claimed in claim 9, characterized in that: The soaking temperature in step nine is 40-80° C., and the soaking time is 2-6 hours.

Images