Surface wet cleaning method for hastelloy part

Abstract

The invention relates to the technical field of semiconductors, in particular to a surface wet cleaning method for a hastelloy part. According to the method, the Hastelloy part is sequentially soaked in the nitric acid solution A, the nitric acid solution B, the concentrated nitric acid and the ultrasonic cleaning, so that the surface metal impurity level is further reduced on the basis of removing pollutants on the surface of the Hastelloy. According to detection of element residues on the surface of the cleaned product, the cleaning method can enable the element residues on the surface of the product to meet the nickel-based alloy cleanliness management and control standards. The cleaning method does not damage the part body, so that the service life of the part is prolonged. The cleaning method is easy and convenient to operate, low in cost and suitable for application and popularization.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and more particularly to a surface wet cleaning method for a Hastelloy component. Background Art

[0002] In semiconductor equipment, chemical vapor deposition process or atomic layer vapor deposition process is often involved. In the vapor deposition process, since the gas in the flow channel is often a highly corrosive gas, higher requirements are placed on the corrosion resistance and strength of the pipes and valve components. Therefore, the pipes and valve components are often made of Hastelloy. Hastelloy is a nickel-based corrosion-resistant alloy, which is mainly divided into two categories: nickel-chromium alloy and nickel-chromium-molybdenum alloy. Hastelloy has good corrosion resistance and thermal stability, so it is widely used in heat exchangers, bellows compensators, chemical equipment, flue gas desulfurization and denitrification, papermaking industry, and aerospace applications. At present, organic solvents are mainly used on the market to clean Hastelloy components of semiconductor equipment, which cannot completely reduce the level of metal impurities on the surface of the components. Therefore, it is of great significance to study the cleaning methods and principles of Hastelloy components.

[0003] At present, the main cleaning method for Hastelloy alloy is wet cleaning. Chinese patent CN105908202A discloses a water-based cleaning agent for cleaning Hastelloy alloy strips, which uses a mixed solution of sodium hydroxide, alkylphenol polyoxyethylene ether, sodium gluconate, alkyl polyoxyethylene sulfate, and sodium carbonate to effectively remove surface pollutants of Hastelloy alloy. However, current research mainly focuses on the removal of pollutants from Hastelloy alloy, and there is no solution to the problem of reducing the level of surface metal impurities.

[0004] Therefore, developing a new wet cleaning process with high cleaning degree and simple procedure is of great significance to improve regeneration cleaning and reduce the level of metal impurities. Summary of the invention

[0005] The purpose of the present invention is to provide a surface wet cleaning method for Hastelloy components, which is used to reduce residual contamination on the surface of components, improve the cleanliness of Hastelloy components, and meet the needs of regeneration and cleaning of semiconductor equipment parts.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A surface wet cleaning method for a Hastelloy component comprises the following steps:

[0008] S1: Place the Hastelloy alloy parts into the first cleaning tank, add an appropriate amount of nitric and fluoric acid solution A, and soak at room temperature for 2-15 minutes;

[0009] S2: Put the Hastelloy alloy parts soaked in step S1 into the second cleaning tank, add an appropriate amount of pure water, and soak them in overflow at room temperature for 15-45 minutes;

[0010] S3: placing the Hastelloy alloy component soaked in step S2 into a third cleaning tank, adding an appropriate amount of nitric and hydrofluoric acid solution B, and soaking at room temperature for 15-45 seconds;

[0011] S4: placing the Hastelloy alloy component soaked in step S3 into a fourth cleaning tank, adding an appropriate amount of concentrated nitric acid solution, and soaking at room temperature for 2-5 minutes;

[0012] S5: placing the Hastelloy alloy parts soaked in step S4 into the fifth cleaning tank, adding an appropriate amount of pure water, and soaking them in overflow at room temperature for 15-45 minutes;

[0013] S6: The Hastelloy alloy parts soaked in step S5 are cleaned with ultrasonic pure water and immersed in overflow at room temperature;

[0014] S7: Drying and dust-free packaging the Hastelloy alloy parts cleaned in step S6.

[0015] The present invention first performs nitric acid and fluoric acid A cleaning, and the purpose of this step is to remove some metal compounds, such as Co / W / Ti / Ta, etc., deposited on the surface of Hastelloy parts during the operation of semiconductor equipment. Utilizing the strong corrosiveness of nitric acid and fluoric acid to metal compounds, most of the metal compounds are dissolved with nitric acid and fluoric acid, and the remaining metal impurities on the surface of the parts are exposed at the same time, as a pre-treatment for subsequent removal of metal ion residues. Secondly, nitric acid and fluoric acid B and concentrated nitric acid cleaning are performed. Nitric acid and fluoric acid B is a mixed solution of low-concentration nitric acid, fluoric acid and water, which can provide F ions and metal ions chelate, and for heavy metal ions such as Co / Fe / Cu / Mn / Cr, it can be effectively removed under chelation. Finally, a combination of pure water rinsing, ultrasonic cleaning and baking is used to remove a small amount of metal residues and micron particles on the surface, and reduce the level of light metal ions such as Na / Mg / K / Ga on the surface of the parts.

[0016] Optionally, in step S6, the ultrasonic frequency is 8-20 W / in 2 , the ultrasonic time is 15-30min.

[0017] Optionally, the first cleaning tank, the second cleaning tank, the third cleaning tank, the fourth cleaning tank and the fifth cleaning tank are all acid- and alkali-resistant plastic tanks, and the material is any one of PTFE, PP, PE, PET or PVC.

[0018] Optionally, in step S6, the overflow of pure water in the pure water tank is greater than 250 L / h, and the resistance of pure water is greater than 2 MΩ; in step S2 and step S5, the pure water is deionized water, and the resistance is greater than 2 MΩ.

[0019] Optionally, in step S1, the nitric and hydrofluoric acid solution A is a mixed solution of electronic grade hydrofluoric acid and electronic grade nitric acid in a volume percentage concentration of (5-25):(75-95), preferably one or more of 5:95, 10:90, 15:85, 20:80 volume percentage concentrations.

[0020] Optionally, in step S3, the nitric and hydrofluoric acid solution B is a mixed solution of electronic grade hydrofluoric acid, electronic grade nitric acid and pure water in a volume percentage concentration of (1-5):(10-30):(60-82), preferably one or more of the volume percentage concentrations of 1:20:79, 2:20:78, 3:20:77, 4:20:76, ​​5:20:75.

[0021] Optionally, in step S4, the concentrated nitric acid solution is a mixed solution of electronic grade nitric acid and pure water with a concentration of 10-50% by volume, preferably one or more of 10:90, 20:80, 30:70, 40:60, 50:50 by volume.

[0022] Optionally, the grade of electronic grade fluoric acid is any one of G2, G3, G4 or G5; the grade of electronic grade nitric acid is any one of G2, G3, G4 or G5.

[0023] Optionally, the normal temperature in steps S1, S2, S3, S4, S5 and S6 is 15-25°C.

[0024] Optionally, step S6 and step S7 are performed in a Class 100 dust-free environment, which is ISO5 clean, with no more than 100 0.5-micron particles and no more than 3,500 5-micron particles per cubic meter of air in the environment.

[0025] In summary, the present application has the following beneficial effects: through the chemical cleaning method, the residual contamination on the surface of the components is effectively reduced, the cleanliness of the Hastelloy components is improved, and the regeneration and cleaning requirements of the components of semiconductor equipment are met. According to the detection of element residues on the surface of the product after cleaning, the cleaning method of the present invention can make the element residues on the surface of the product meet the cleanliness control standards of nickel-based alloys. The cleaning method of the present invention does not damage the component body, thereby increasing the service life of the component. The cleaning method of the present invention is easy to operate, low in cost, and suitable for promotion and use. DETAILED DESCRIPTION

[0026] The following embodiments are used to describe the present invention in detail, but the protection scope of the present invention is not limited to the following embodiments. The raw materials and equipment used in the present invention can be obtained from the market. The experimental methods in the following embodiments that do not specify specific conditions are usually based on conventional conditions or conditions recommended by the manufacturer.

[0027] Example 1

[0028] A surface wet cleaning method for a Hastelloy component comprises the following steps:

[0029] S1: Put the Hastelloy alloy component into the first cleaning tank, add an appropriate amount of nitric and fluoric acid solution A (enough to submerge the Hastelloy alloy component), and soak it at room temperature for 3 minutes; wherein the nitric and fluoric acid solution A is a mixed solution of electronic grade fluoric acid and electronic grade nitric acid with a volume percentage concentration of 15:85;

[0030] S2: Put the Hastelloy alloy parts soaked in step S1 into the second cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy parts), and soak them in overflow at room temperature for 30 minutes;

[0031] S3: putting the Hastelloy alloy parts soaked in step S2 into a third cleaning tank, adding an appropriate amount of nitric and fluoric acid solution B (capable of submerging the Hastelloy alloy parts), and soaking at room temperature for 20 seconds; wherein the nitric and fluoric acid solution B is a mixed solution of electronic grade fluoric acid, electronic grade nitric acid and pure water with a volume percentage concentration of 5:20:75;

[0032] S4: placing the Hastelloy alloy component soaked in step S3 into a fourth cleaning tank, adding an appropriate amount of concentrated nitric acid solution (capable of submerging the Hastelloy alloy component), and soaking for 5 minutes at room temperature; wherein the concentrated nitric acid solution is a mixed solution of electronic grade nitric acid and pure water with a volume percentage concentration of 40:60;

[0033] S5: Put the Hastelloy alloy parts soaked in step S4 into the fifth cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy parts), and soak them in overflow at room temperature for 30 minutes;

[0034] S6: The Hastelloy alloy parts soaked in step S5 are transferred to a Class 100 clean room for ultrasonic pure water cleaning, and are immersed in overflow at room temperature with an ultrasonic frequency of 12w / in 2 , ultrasound time was 24min;

[0035] S7: The Hastelloy alloy parts cleaned in step S6 are transferred to a Class 100 dust-free oven for drying at a drying temperature of 150° C. for 2 hours, and then dust-free packaging is performed.

[0036] Example 2

[0037] A surface wet cleaning method for a Hastelloy component comprises the following steps:

[0038] S1: Put the Hastelloy alloy component into the first cleaning tank, add an appropriate amount of nitric and fluoric acid solution A (enough to submerge the Hastelloy alloy component), and soak it at room temperature for 5 minutes; wherein the nitric and fluoric acid solution A is a mixed solution of electronic grade fluoric acid and electronic grade nitric acid with a volume percentage concentration of 15:85;

[0039] S2: Put the Hastelloy alloy parts soaked in step S1 into the second cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy parts), and soak them in overflow at room temperature for 45 minutes;

[0040] S3: placing the Hastelloy alloy component soaked in step S2 into a third cleaning tank, adding an appropriate amount of nitric and fluoric acid solution B (capable of submerging the Hastelloy alloy component), and soaking at room temperature for 30 seconds; wherein the nitric and fluoric acid solution B is a mixed solution of electronic grade fluoric acid, electronic grade nitric acid and pure water with a volume percentage concentration of 5:20:75;

[0041] S4: placing the Hastelloy alloy component soaked in step S3 into a fourth cleaning tank, adding an appropriate amount of concentrated nitric acid solution (capable of submerging the Hastelloy alloy component), and soaking for 2 minutes at room temperature; wherein the concentrated nitric acid solution is a mixed solution of electronic grade nitric acid and pure water with a volume percentage concentration of 40:60;

[0042] S5: Put the Hastelloy alloy parts soaked in step S4 into the fifth cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy parts), and soak them in overflow at room temperature for 45 minutes;

[0043] S6: The Hastelloy alloy parts soaked in step S5 are transferred to a Class 100 clean room for ultrasonic pure water cleaning, and are immersed in overflow at room temperature with an ultrasonic frequency of 15w / in 2 , ultrasound time was 20min;

[0044] S7: The Hastelloy alloy parts cleaned in step S6 are transferred to a Class 100 dust-free oven for drying at a drying temperature of 120° C. for 4 hours, and then dust-free packaging is performed.

[0045] Example 3

[0046] A surface wet cleaning method for a Hastelloy component comprises the following steps:

[0047] S1: Put the Hastelloy alloy component into the first cleaning tank, add an appropriate amount of nitric and fluoric acid solution A (enough to submerge the Hastelloy alloy component), and soak it at room temperature for 3 minutes; wherein the nitric and fluoric acid solution A is a mixed solution of electronic grade fluoric acid and electronic grade nitric acid with a volume percentage concentration of 25:75;

[0048] S2: Put the Hastelloy alloy parts soaked in step S1 into the second cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy parts), and soak them in overflow at room temperature for 30 minutes;

[0049] S3: putting the Hastelloy alloy parts soaked in step S2 into a third cleaning tank, adding an appropriate amount of nitric and fluoric acid solution B (capable of submerging the Hastelloy alloy parts), and soaking at room temperature for 20 seconds; wherein the nitric and fluoric acid solution B is a mixed solution of electronic grade fluoric acid, electronic grade nitric acid and pure water with a volume percentage concentration of 3:15:82;

[0050] S4: placing the Hastelloy alloy component soaked in step S3 into a fourth cleaning tank, adding an appropriate amount of concentrated nitric acid solution (capable of submerging the Hastelloy alloy component), and soaking for 5 minutes at room temperature; wherein the concentrated nitric acid solution is a mixed solution of electronic grade nitric acid and pure water with a volume percentage concentration of 30:70;

[0051] S5: Put the Hastelloy alloy parts soaked in step S4 into the fifth cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy parts), and soak them in overflow at room temperature for 30 minutes;

[0052] S6: The Hastelloy alloy parts soaked in step S5 are transferred to a Class 100 clean room for ultrasonic pure water cleaning, and are immersed in overflow at room temperature with an ultrasonic frequency of 15w / in 2 , ultrasound time is 30min;

[0053] S7: The Hastelloy alloy parts cleaned in step S6 are transferred to a Class 100 dust-free oven for drying at a drying temperature of 150° C. for 2 hours, and then dust-free packaging is performed.

[0054] Comparative Example 1

[0055] A method for cleaning a Hastelloy component comprises the following steps:

[0056] S1: Place the Hastelloy alloy component into the first cleaning tank, add an appropriate amount of water-based cleaning agent (capable of submerging the Hastelloy alloy component), and soak at room temperature for 5 minutes; wherein the formula of the water-based cleaning agent is the formula recorded in Example 3 of CN105908202A patent;

[0057] S2: Put the Hastelloy alloy parts soaked in step S1 into the second cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy parts), and soak them in overflow at room temperature for 30 minutes;

[0058] S3: Put the Hastelloy alloy parts soaked in step S2 into a third cleaning tank, add an appropriate amount of water-based cleaning agent (capable of submerging the Hastelloy alloy parts), and soak at room temperature for 20 seconds; wherein the formula of the water-based cleaning agent is the formula recorded in Example 3 of CN105908202A patent;

[0059] S4: Put the Hastelloy alloy component soaked in step S3 into the fifth cleaning tank, add an appropriate amount of pure water (enough to submerge the Hastelloy alloy component), and soak it in overflow at room temperature for 30 minutes;

[0060] S5: The Hastelloy alloy parts soaked in step S4 are transferred to a Class 100 clean room for ultrasonic pure water cleaning. The pure water temperature is adjusted to 60°C, overflow soaking, and the ultrasonic frequency is 10w / in 2 , ultrasound time is 30min;

[0061] S6: The Hastelloy alloy parts cleaned in step S7 are transferred to a Class 100 dust-free oven for drying at a drying temperature of 150° C. for a drying time of 2 h, and then dust-free packaging is performed.

[0062] Comparative Example 2

[0063] A method for cleaning a Hastelloy component, compared with Example 1, omits steps S1 and S2, directly puts the Hastelloy component into a third cleaning tank, and performs steps S3 to S7.

[0064] Comparative Example 3

[0065] A method for cleaning a Hastelloy alloy component, compared with Example 1, omits steps S3 to S5, transfers the Hastelloy alloy component soaked in step S2 to a Class 100 clean room for ultrasonic pure water cleaning, and performs steps S6 to S7.

[0066] The cleaned Hastelloy parts of Examples 1-3 and Comparative Examples 1-3 were subjected to I CP-MS (i.e., inductively coupled plasma-mass spectrometry) detection to detect the metal element levels on the surface of the Hastelloy parts. The test results are shown in Tables 1 and 2. The test results of Examples 1-3 meet the cleanliness control standards for nickel-based alloys.

[0067] Table 1: Surface element residue detection data of Examples 1 to 3

[0068]

[0069] Table 2: Surface element residue detection data of Comparative Examples 1-3

[0070]

[0071] As can be seen from Tables 1 and 2, the chemical cleaning method effectively reduces the residual contamination on the surface of the components, improves the cleanliness of the Hastelloy components, and meets the needs of regeneration and cleaning of semiconductor equipment components. According to the detection of element residues on the surface of the product after cleaning, the cleaning method of the present invention can make the element residues on the surface of the product meet the cleanliness control standards of nickel-based alloys. The cleaning method of the present invention does not damage the component body, thereby increasing the service life of the component. The cleaning method of the present invention is easy to operate, low in cost, and suitable for promotion and use.

[0072] The above specific embodiments are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the embodiments without any creative contribution as needed. However, as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A surface wet cleaning method for Hastelloy parts, characterized in that: The following steps are involved: S1: Place the Hastelloy alloy parts into the first cleaning tank, add an appropriate amount of nitric and fluoric acid solution A, and soak at room temperature for 2-15 minutes; S2: Put the Hastelloy alloy parts soaked in step S1 into the second cleaning tank, add an appropriate amount of pure water, and soak them in overflow at room temperature for 15-45 minutes; S3: placing the Hastelloy alloy component soaked in step S2 into a third cleaning tank, adding an appropriate amount of nitric and hydrofluoric acid solution B, and soaking at room temperature for 15-45 seconds; S4: placing the Hastelloy alloy component soaked in step S3 into a fourth cleaning tank, adding an appropriate amount of concentrated nitric acid solution, and soaking at room temperature for 2-5 minutes; S5: placing the Hastelloy alloy parts soaked in step S4 into the fifth cleaning tank, adding an appropriate amount of pure water, and soaking them in overflow at room temperature for 15-45 minutes; S6: The Hastelloy alloy parts soaked in step S5 are cleaned with ultrasonic pure water and immersed in overflow at room temperature; S7: Drying and dust-free packaging the Hastelloy alloy parts cleaned in step S6.

2. The surface wet cleaning method according to claim 1, characterized in that: In step S6, the ultrasonic frequency is 8-20W / in 2 , the ultrasonic time is 15-30min.

3. The surface wet cleaning method according to claim 1, characterized in that: The first cleaning tank, the second cleaning tank, the third cleaning tank, the fourth cleaning tank and the fifth cleaning tank are all acid- and alkali-resistant plastic tanks, and the material is any one of PTFE, PP, PE, PET or PVC.

4. The surface wet cleaning method according to claim 1, characterized in that: In step S6, the overflow of pure water in the pure water tank is greater than 250 L / h, and the resistance of pure water is greater than 2 MΩ; in step S2 and step S5, the pure water is deionized water, and the resistance is greater than 2 MΩ.

5. The surface wet cleaning method according to claim 1, characterized in that: In step S1, the nitric and hydrofluoric acid solution A is a mixed solution of electronic grade hydrofluoric acid and electronic grade nitric acid with a volume percentage concentration of (5-25):(75-95).

6. The surface wet cleaning method according to claim 1, characterized in that: In step S3, the nitric and hydrofluoric acid solution B is a mixed solution of electronic grade hydrofluoric acid, electronic grade nitric acid and pure water with a volume percentage concentration of (1-5):(10-30):(60-82).

7. The surface wet cleaning method according to claim 1, characterized in that: In step S4, the concentrated nitric acid solution is a mixed solution of electronic grade nitric acid and pure water with a concentration of 10-50% by volume.

8. The surface wet cleaning method according to claim 5 or 7, characterized in that: The grade of electronic grade fluoric acid is any one of G2, G3, G4 or G5; the grade of electronic grade nitric acid is any one of G2, G3, G4 or G5.

9. The surface wet cleaning method according to claim 1, characterized in that: The normal temperature in steps S1, S2, S3, S4, S5 and S6 is 15-25°C.

10. The surface wet cleaning method according to claim 1, characterized in that: Step S6 and step S7 are performed in a Class 100 dust-free environment.

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