Process for removing metal ions from device of semiconductor preparation equipment

Abstract

The invention aims to provide the process for removing the metal ions of the device of the semiconductor preparation equipment, which is good in cleaning effect, environment-friendly, thorough in cleaning of the surface of the device and free of damage to the device. The technology comprises the following steps that a, a device to be cleaned is hung in a cleaning tank (1) through a hanging device (3) with an overturning function, the device is completely immersed in ozone micro-bubble water, the water temperature in the cleaning tank is 30-40 DEG C, and the device is overturned in the water through the hanging device; b, after the set first cleaning time is reached, the hanging device stops overturning, and the micro bubble water generating device (2) stops working; c, the cleaning tank is emptied, ozone micro-bubble water is injected again, and after the device is completely immersed, the hanging device continues to drive the device to turn over in the water for set second cleaning time; and d, the hanging device stops working, the micro-bubble water generating device stops working, and the cleaned device is taken out and dried. The invention can be applied to the technical field of cleaning.

Description

Technical Field

[0001] The invention relates to the field of cleaning technology, and in particular to a process for removing metal ions from devices of semiconductor manufacturing equipment. Background Art

[0002] Semiconductor materials are an extremely important means of production in the entire industrial field. Various processing equipment, jigs, etc. are needed when preparing semiconductor materials. In order to ensure the accuracy and quality of semiconductor preparation, it is necessary to demetallize the surfaces of various processing equipment, jigs, etc. used. At present, the more common methods of removing metal ions from the surface of semiconductor preparation equipment in the industry generally use chemical precipitation / ion exchange / membrane separation methods to remove metal ions on the surface of the equipment, so as to remove positive ions, iron ions, copper ions, aluminum ions, nickel ions, etc. on the surface of the equipment. However, for sodium ions that are difficult to remove and sulfate ions, nitrate ions, etc. present in the cutting fluid used in processing, it requires a higher cost to complete, and may be accompanied by the risk of environmental pollution. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a process for removing metal ions from devices of semiconductor manufacturing equipment which has good cleaning effect, is environmentally friendly, cleans the device surface thoroughly and does not damage the device.

[0004] The present invention adopts a comprehensive method of ion exchange and oxidation-reduction, and uses high-concentration ozone and micro-bubble cleaning technology to clean metal ions.

[0005] It is emphasized again that the present invention has the advantages of simple operation, low cost, good effect, environmental protection and energy-saving green invasion process and technology.

[0006] The technical solution adopted by the present invention is a process for removing metal ions from devices of semiconductor manufacturing equipment. The process is carried out in a cleaning tank filled with high-concentration ozone fine bubble water. A fine bubble water generating device is provided on one side of the cleaning tank to continuously introduce ozone fine bubble water into the cleaning tank. After the cleaning tank is filled with water, it overflows naturally. The process comprises the following steps:

[0007] a. Hang the device to be cleaned in the cleaning tank through a hanging device with a flipping function, and immerse the device completely in the ozone fine bubble water. At this time, the water temperature in the cleaning tank is 30-40°C, and the device is flipped in the water through the hanging device;

[0008] b. After the set first cleaning time is reached, the hanging device stops turning over and the micro-bubble water generating device stops working;

[0009] c. Empty the cleaning tank and refill it with ozone fine bubble water. After the device is completely immersed, the hanging device continues to drive the device to flip in the water for the set second cleaning time;

[0010] d. After the set second cleaning time is over, the hanging device stops working, the fine bubble water generating device stops working, the cleaned device is taken out and dried, and the cleaning operation is completed.

[0011] It can be seen from the above scheme that in the present invention, by hanging the semiconductor device in the cleaning tank and utilizing the flipping effect of the hanging device, the semiconductor device is fully cleaned in the ozone micro-bubble water, and the micro-bubble water generating device continuously introduces the ozone micro-bubble water into the cleaning tank, and the cleaning tank overflows naturally after being filled with water, which can ensure that the cleaning effect in the cleaning tank is always maintained at the optimal level; after testing, each bubble surface in the ozone micro-bubble water will carry an electric charge, and the surface charge of the micro-bubble continues to concentrate as the bubble shrinks. When the micro-bubble shrinks and disappears in the water, the stored pressure and electric charge potential are released, and its energy produces strong oxidative active substances, such as carboxyl Free radicals (strong oxidants) use strong oxidizing active substances to oxidize and clean the various metal ions on the surface of semiconductor devices. At the same time, the super strong oxidizing ability of ozone can help the metal ions to be immediately oxidized after stripping, so as to prevent secondary pollution. Then, the flipping of the hanging device is used to drive the cleaned semiconductor device to rotate in the ozone fine bubble water, and the impact of the water flow is used to further clean the surface of the semiconductor device, thereby ensuring the cleaning effect of the semiconductor device. Compared with the prior art, the process of the present invention does not need to add chemicals to cause secondary pollution or damage to the semiconductor device, so as to achieve harmless, green and environmentally friendly cleaning. In addition, the process of the present invention is simple and easy to operate.

[0012] Furthermore, the first cleaning time is 10 minutes, and the second cleaning time is 5 minutes. It can be seen from the above scheme that the semiconductor device can be cleaned more thoroughly through two cleanings.

[0013] Furthermore, the micro-bubble water generating device is connected to a plurality of delivery pipes, and the water outlets of the delivery pipes are arranged at the inner bottom of the cleaning tank. It can be seen that the ozone micro-bubble water is directly delivered to the bottom of the cleaning tank through the delivery pipes, so that the entire cleaning tank is filled with micro-bubbles and evenly distributed, ensuring the cleaning effect.

[0014] Furthermore, the hanging device includes a material frame for holding devices and immersed in ozone fine bubble water, a hanging rope for hanging the material frame, a bracket, a swing roller, and a swing motor for driving the swing roller to swing, and the upper end of the hanging rope is connected to the swing roller. The swing motor enables the semiconductor device immersed in the ozone fine bubble water to swing automatically, and automatically clean, thereby improving automation.

[0015] More specifically, the upper end of the hanging rope is connected to the outer wall surface of the swing roller and is located in the middle. At this time, the hanging rope drives the material frame to swing back and forth in the ozone fine bubble water. Alternatively, the hanging rope is wrapped around the outer wall surface of the swing roller. At this time, the hanging rope reciprocates up and down under the action of the swing roller, further driving the material frame to move up and down, so that the semiconductor devices in the material frame are cleaned.

[0016] Furthermore, the swing motor is a stepping motor. It can be seen that the use of a stepping motor to drive the swing roller to rotate can ensure the rotation angle range adjustment and rotation accuracy of the swing roller, thereby ensuring a better cleaning effect.

[0017] Furthermore, the concentration of ozone introduced into the micro-bubble water generating device is 150mg / L to 220mg / L. Here, changing the ozone concentration and capacity according to the process requirements is also an important technical process parameter of the invention. At the same time, the cleaning time and ozone concentration are adjusted according to the cleaning requirements of the cleaning device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a simplified structural schematic diagram of a cleaning device involved in the process of the present invention;

[0019] Figure 2 It is a simplified structural diagram of the first structure between the hanging rope and the swing roller;

[0020] Figure 3 It is a simplified structural diagram of the second structure between the hanging rope and the swing roller;

[0021] Figure 4 It is a simplified structural schematic diagram of the micro-bubble water generating device. DETAILED DESCRIPTION

[0022] like Figures 1 to 4 As shown, in the process of the present invention, the process is carried out in a cleaning tank 1 filled with high-concentration ozone fine bubble water. A fine bubble water generator 2 is provided on one side of the cleaning tank 1 to continuously introduce ozone fine bubble water into the cleaning tank 1. In this embodiment, the concentration of ozone introduced into the fine bubble water generator 2 is 150 mg / L to 220 mg / L, specifically 180 mg / L. After the cleaning tank 1 is filled with water, it overflows naturally. The process includes the following steps:

[0023] a. Hang the device to be cleaned in the cleaning tank 1 through the hanging device 3 with a flipping function, and immerse the device completely in the ozone fine bubble water. At this time, the water temperature in the cleaning tank 1 is 30-40° C. The device is flipped in the water through the hanging device 3;

[0024] b. After the set first cleaning time of 10 minutes is reached, the hanging device 3 stops turning over and the micro-bubble water generating device 2 stops working;

[0025] c. Empty the cleaning tank 1 and refill it with ozone fine bubble water. After the device is completely immersed, the hanging device 3 continues to drive the device to flip in the water for a set second cleaning time of 5 minutes;

[0026] d. After the set second cleaning time is over, the hanging device 3 stops working, the micro-bubble water generating device 2 stops working, the cleaned device is taken out and dried, and the cleaning operation is completed.

[0027] Furthermore, the micro-bubble water generating device 2 is connected to a plurality of conveying pipes, and the water outlets of the conveying pipes are arranged at the inner bottom of the cleaning tank 1. The hanging device 3 includes a material frame 31 for holding devices and immersed in ozone micro-bubble water, a hanging rope 32 for hanging the material frame 31, a bracket 33, a swing roller 34, and a swing motor 35 for driving the swing roller 34 to swing. In this embodiment, the swing motor 35 is a stepping motor. The upper end of the hanging rope 32 is connected to the swing roller 34. The upper end of the hanging rope 32 is connected to the outer wall surface of the swing roller 34 and is located in the middle. The hanging rope 32 is wound around the outer wall surface of the swing roller 34.

[0028] The micro-bubble water generating device 2 comprises a dissolving tank 21, a pure water tank 22, a transfer pump 23, an injection pipe 24 disposed in the dissolving tank 21, an outlet pipe 25 connected to the dissolving tank 21, a pressure relief valve 26 and an ozone generating device 27. The pure water tank 22 and the ozone generating device 27 respectively send out pure water and ozone, which then pass through the transfer pump 23 and enter the injection pipe 24 in the dissolving tank 21. The injection pipe 24 injects the water-gas mixture into the injection pipe 24. The discharge pipe 25 delivers the water-gas mixture in the dissolving tank 21 to the cleaning tank 1. The pressure relief valve 26 is arranged at the upper part of the dissolving tank 21. A liquid level gauge is arranged in the dissolving tank 21. The liquid level gauge is connected to the pressure relief valve 26 for operation. The micro-bubble water generating device generates ozone micro-bubble water by introducing ozone into ultrapure water. The bubble diameter range of the ozone micro-bubble water is 100nm to 50μm. Specifically, the transfer pump 23 is a diaphragm pump, which is a positive displacement pump. Here, the diaphragm of the diaphragm pump is formed of fluororesin, thereby effectively preventing the cleaning water from being contaminated by metal. Injection holes are provided on the periphery of the injection pipe 24. These injection holes will spray the mixed liquid delivered by the delivery pump toward the inner wall of the dissolving tank, so that the micro-bubbles in the liquid in the dissolving tank are more evenly distributed. The pressure relief valve 26 discharges the gas that cannot be dissolved in the dissolving tank. The liquid level gauge keeps the liquid level in the dissolving tank constant to ensure the smooth progress of the cleaning work.

[0029] The present invention will be further described below with reference to specific embodiments.

[0030] Embodiment 1:

[0031] The stainless steel tube (specification: outer diameter 6mm, inner diameter 4.24mm) was cleaned using the above process. After cleaning, the SCTC-S-030ICP-MS trace metal element analysis solid sample standard procedure was used for testing. The test items included Ca, Cu, Mn, Ni, and Na. After testing, the following test results were obtained:

[0032] Test items Method detection limit Test Results unit Ca 30.0 532.8 <![CDATA[10 10 atoms / cm 2 ]]> Cu 1.0 383.2 <![CDATA[10 10 atoms / cm 2 ]]> Mn 10.0 225.6 <![CDATA[10 10 atoms / cm 2 ]]> Na 10.0 481.3 <![CDATA[10 10 atoms / cm 2 ]]> Ni 5.0 391.7 <![CDATA[10 10 atoms / cm 2 ]]>

[0033] Embodiment 2:

[0034] After cleaning, the stainless steel (surface area 94.20cm 2 ) was soaked in ultrapure water for 24 hours, and then the content of particles of different sizes in the 150ml soaking liquid was detected. The results are as follows:

[0035]

[0036]

[0037] Embodiment three:

[0038] After cleaning, the stainless steel (surface area 94.20cm 2 ) Soak in ultrapure water for 24 hours, then test the content of anions and cations in 150 ml of soaking liquid at room temperature. The results are as follows:

[0039] Ion name Measurement results Method detection limit unit <![CDATA[Na + ]]> 20.9 2.6 <![CDATA[10 12 molecules / cm 2 ]]> <![CDATA[NH 4 + ]]> 53.3 6.7 <![CDATA[10 12 molecules / cm 2 ]]> <![CDATA[Mg 2+ ]]> 19.7 5.0 <![CDATA[10 12 molecules / cm 2 ]]> <![CDATA[Ca 2+ ]]> 110.3 4.5 <![CDATA[10 12 molecules / cm 2 ]]> <![CDATA[C1 - ]]> 18.9 0.3 <![CDATA[10 12 molecules / cm 2 ]]> <![CDATA[S0 4 2- ]]> 12.7 0.1 <![CDATA[10 12 molecules / cm 2 ]]>

[0040] It can be seen from the above test results that the cleaning requirements of metal ions in semiconductor devices can be well met by using the process of the present invention to clean semiconductor devices.

[0041] It should be noted that the above test results are only for reference and cleaning result evaluation. The detailed evaluation shall be in accordance with industry standards and regulations of each enterprise.

[0042] The invention is applied to cleaning semiconductor devices and can quickly and thoroughly remove the anions and cations that are difficult to remove on the device surface.

[0043] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for removing metal ions from devices of semiconductor manufacturing equipment, the process being carried out in a cleaning tank (1) filled with high-concentration ozone fine bubble water, a fine bubble water generating device (2) being provided on one side of the cleaning tank (1) to continuously introduce ozone fine bubble water into the cleaning tank (1), the cleaning tank (1) naturally overflowing after being filled with water, characterized in that: The process includes the following steps: a. Hanging the device to be cleaned in the cleaning tank (1) by means of a hanging device (3) with a flipping function, and completely immersing the device in the ozone fine bubble water. At this time, the water temperature in the cleaning tank (1) is 30 to 40° C., and the device is flipped in the water by means of the hanging device (3); b. After the set first cleaning time is reached, the hanging device (3) stops turning over and the micro-bubble water generating device (2) stops working; c. Emptying the cleaning tank (1), refilling it with ozone fine bubble water, and after the device is completely immersed, the hanging device (3) continues to drive the device to flip in the water for a set second cleaning time; d. After the set second cleaning time is over, the hanging device (3) stops working, the micro-bubble water generating device (2) stops working, the cleaned device is taken out and dried, and the cleaning operation is completed.

2. The process for removing metal ions from a device of a semiconductor manufacturing equipment according to claim 1, characterized in that: The first cleaning time is 10 minutes, and the second cleaning time is 5 minutes.

3. The process for removing metal ions from a device of a semiconductor manufacturing equipment according to claim 1, characterized in that: The micro-bubble water generating device (2) is connected to a plurality of delivery pipes, and the water outlets of the delivery pipes are arranged at the inner bottom of the cleaning tank (1).

4. The process for removing metal ions from a device of a semiconductor manufacturing equipment according to claim 1, characterized in that: The hanging device (3) comprises a material frame (31) for containing devices and immersed in ozone fine bubble water, a hanging rope (32) for hanging the material frame (31), a bracket (33), a swing roller (34) and a swing motor (35) for driving the swing roller (34) to swing, and the upper end of the hanging rope (32) is connected to the swing roller (34).

5. The process for removing metal ions from a device of a semiconductor manufacturing equipment according to claim 4, characterized in that: The upper end of the hanging rope (32) is connected to the outer wall surface of the swing roller (34) and is located in the middle.

6. The process for removing metal ions from a device of a semiconductor manufacturing equipment according to claim 4, characterized in that: The hanging rope (32) is wound around the outer wall surface of the swing roller (34).

7. The process for removing metal ions from a device of a semiconductor manufacturing equipment according to claim 5, characterized in that: The swing motor (35) is a stepping motor.

8. The process for removing metal ions from a device of a semiconductor manufacturing equipment according to claim 1, characterized in that: The concentration of ozone introduced into the fine bubble water generating device (2) is 150 mg / L to 220 mg / L.

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