WO2020075844A1 - Fine-bubble cleaning device and fine-bubble cleaning method - Google Patents

Fine-bubble cleaning device and fine-bubble cleaning method Download PDF

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Publication number
WO2020075844A1
WO2020075844A1 PCT/JP2019/040253 JP2019040253W WO2020075844A1 WO 2020075844 A1 WO2020075844 A1 WO 2020075844A1 JP 2019040253 W JP2019040253 W JP 2019040253W WO 2020075844 A1 WO2020075844 A1 WO 2020075844A1
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Prior art keywords
cleaning
bubble
cleaning liquid
nano
bubbles
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PCT/JP2019/040253
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French (fr)
Japanese (ja)
Inventor
日高　義晴
義勝 上田
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パナソニックＩｐマネジメント株式会社
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Priority to JP2020551246A priority Critical patent/JPWO2020075844A1/en
Publication of WO2020075844A1 publication Critical patent/WO2020075844A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
    • B08B3/02—Cleaning by the force of jets or sprays
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B08—CLEANING
    • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
    • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
    • B08B3/04—Cleaning involving contact with liquid
    • B08B3/10—Cleaning involving contact with liquid with additional treatment of the liquid or of the object being cleaned, e.g. by heat, by electricity or by vibration
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
    • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting

Definitions

  • the present invention relates to a cleaning device and a cleaning method using fine bubbles.
  • a method of using a brush, a method of jetting a gas and a liquid at the same time to form a droplet (two-fluid cleaning), and a method of vibrating the liquid with ultrasonic waves are widely used.
  • the surface potential of the foreign matter is controlled. The surface potential of the foreign matter is controlled by controlling the pH of the liquid to the alkaline side.
  • Nano bubbles Fine bubbles are divided into nano bubbles of 1 nm to less than 1 ⁇ m (hereinafter referred to as “nano bubbles”) and micro bubbles of 1 ⁇ m to 100 ⁇ m (hereinafter referred to as “micro bubbles”). Among them, it was found that the lifetime of nano bubbles is as long as several months, but the lifetime of micro bubbles is much shorter than that of nano bubbles.
  • the micro bubbles in the cleaning liquid are destroyed and disappear during the transfer by the pipe, and unless the object to be cleaned can be reached, the energy at the time of the destruction of the micro bubbles cannot be effectively utilized. There were challenges.
  • the present invention was conceived in view of the above problems. From the phenomenon that the bubble diameter increases due to the nozzle injection of the fine bubble cleaning liquid described later, it has been found that the combination of the cleaning nozzle and the collision processing body is suitable as the bubble spontaneous collapse device of Patent Document 2. Furthermore, the inventors have found an invention in which a combination of a cleaning nozzle and a collision processing body is provided immediately before being supplied to a cleaning target. Thus, of the fine bubbles, micro-order fine bubbles are generated in the vicinity of the object to be cleaned, and a cleaning device is provided that effectively utilizes the energy at the time of destruction of the fine bubbles to improve the cleaning capability. Is.
  • the fine bubble cleaning device according to the present invention, A micro-bubble generator that generates at least nano-order micro bubbles in the cleaning liquid to generate nano-bubble cleaning liquid, A cleaning nozzle for ejecting the nano-bubble cleaning liquid toward the object to be cleaned, It has a collision processing body provided between the cleaning nozzle and the object to be cleaned.
  • the micro-bubble cleaning device changes the nano-bubbles into micro-bubbles by hitting the nano-bubbles once on the collision-treated body before ejecting the nano-bubbles onto the object to be cleaned. That is, micro bubbles are generated from the nano bubbles just before the object to be cleaned, and the nano bubbles and the micro bubbles are supplied to the object to be cleaned.
  • a high-speed camera analyzes the results of what kind of bubbles are generated after purified water with a dissolved oxygen content of 32 ppm and a dissolved oxygen content of 7 ppm collides with the liquid surface in a state where the spray force is small (spray height 180 mm). Show. It is a graph which shows the result of having measured the temperature change when a nano-bubble cleaning liquid is applied to the slope with a thermocouple. It is a figure which shows the structure which performed the Example which confirms the effect at the time of making a collision process body into a liquid. It is a figure which shows the state below 1 mm of liquid level. It is an enlarged view of FIG.8 (b). It is a photograph which shows the result at the time of using a nano bubble cleaning liquid and purified water. 14 is a graph showing the result of image processing of the result of FIG. 13.
  • the fine bubble cleaning apparatus 1 is mainly used in a chemical treatment process and a cleaning process of semiconductors and electronic parts formed by photolithography.
  • the fine bubble cleaning device 1 performs cleaning by removing deposits adhering to these surfaces and replacing chemical liquid components with cleaning water.
  • the fine bubble cleaning device 1 can also be used for cleaning the inner wall in the liquid supply pipe.
  • FIG. 1 shows the configuration of a fine bubble cleaning device 1 according to the present invention.
  • the fine bubble cleaning device 1 according to the present invention includes a fine bubble generating device 10 and a cleaning tank 14. An object to be cleaned Pro is placed in the cleaning tank 14. Further, a cleaning nozzle 14 a and a collision processing body 26 are also arranged in the cleaning tank 14. Further, the fine bubble cleaning device 1 may have a storage tank 16.
  • the fine bubble generator 10 is a device that generates nano bubbles nB having a bubble diameter of at least nano-order (1 nm or more and less than 1 ⁇ m) in the cleaning liquid W to generate the nano bubble cleaning liquid WnB.
  • the nanobubble cleaning liquid WnB may include microbubbles ⁇ B having a diameter of micron order (1 ⁇ m or more and 100 ⁇ m or less). However, even if the micro bubbles ⁇ B are mixed in the cleaning liquid W at the point of the fine bubble generator 10, a considerable portion of the micro bubbles ⁇ B disappear while being transferred to the cleaning tank 14.
  • the cleaning liquid W pure water, ion-exchanged water, or the like can be preferably used. However, other polar solvents or non-polar solvents may be used.
  • the cleaning liquid W is supplied from a cleaning water supply source (not shown).
  • the nano bubbles nB may be air, but N 2 (nitrogen), O 2 (oxygen), H 2 (hydrogen), Ar (argon), Xe (xenon), and O 3 (ozone) may be used alone or in combination. It may be used as a mixed gas of.
  • a gas supply source Gas may be provided when using a gas other than air.
  • the cleaning tank 14 is a container for bringing the short-life bubble cleaning liquid WBs, which will be described later, into contact with the cleaning target Pro.
  • the contacting includes a method of spraying the short-lived bubble cleaning liquid WBs on the cleaning target Pro (discharging: also including a shower), and immersing the cleaning target Pro in the short-life bubble cleaning liquid WBs (dip).
  • FIG. 2 shows the inside of the cleaning tank 14 more specifically.
  • the cleaning nozzle 14a, the collision processing body 26, and the cleaning target Pro are arranged.
  • the object to be cleaned Pro is a semiconductor substrate or an electronic device produced by photolithography, and one that has been exposed can be illustrated as a typical example.
  • the cleaning tank 14 may be provided with a chemical solution device 70 that processes the exposed cleaning object Pro with a chemical solution.
  • the chemical liquid device 70 includes a disk 71 to which the cleaning target Pro is sucked and fixed, a chemical liquid nozzle 72 that discharges the chemical liquid to the cleaning target Pro, a chemical liquid tank 73 that supplies the chemical liquid to the chemical liquid nozzle 72, a pump 74, and a filter 75. Is formed by.
  • the chemical treatment means a kind of treatment for removing the resist from the cleaning target Pro after the development.
  • the cleaning tank 14 is provided with a cleaning nozzle 14a for ejecting the nano-bubble cleaning liquid WnB toward the cleaning target Pro.
  • the collision processing body 26 is disposed between the cleaning nozzle 14a and the cleaning target Pro.
  • the nano-bubble cleaning liquid WnB becomes the short-lived bubble cleaning liquid WBs after colliding with the collision processing body 26 at least once, and is brought into contact with the cleaning target Pro.
  • the fine bubble cleaning apparatus 1 mainly includes the cleaning liquid W, the fine bubble generating apparatus 10, the cleaning nozzle 14a, and the collision processing body 26. Further, the storage tank 16, the first bubble monitor 20, the second bubble monitor 22, and the control device 30 can be further provided.
  • the storage tank 16 is a container for storing the nano bubble cleaning liquid WnB generated by the fine bubble generating device 10.
  • the volume of the storage tank 16 can be appropriately determined depending on the scale of the fine bubble cleaning device 1.
  • the first bubble monitor 20 and the second bubble monitor 22 are devices that measure the density of the nano bubbles nB in the nano bubble cleaning liquid WnB. This is an apparatus for measuring the number of nanobubbles nB in a unit volume or the density of nanobubbles nB using a laser.
  • the first bubble monitor 20 and the second bubble monitor 22 may be devices that measure heat or energy such as temperature between a certain distance between the pipe r2 and the return pipe r3 as a method other than laser. This is because the number of nanobubbles nB or the density of nanobubbles nB in a unit volume can be measured from the difference between the measured values.
  • control device 30 a computer including an MPU (Micro Processor Unit) and a memory can be preferably used.
  • the control device 30 is connected to the first bubble monitor 20 and the second bubble monitor 22. Further, it may be connected to a pump or the like that determines the flow rate. Each pump is configured so that its movement can be controlled by a signal from the control device 30.
  • the storage tank 16 is provided with a circulation pipe r1.
  • a fine bubble generator 10 is arranged in the circulation pipe r1. Further, a gas supply source Gas may be connected to the fine bubble generator 10.
  • the circulation pipe r1 is provided with a pump P1 that determines the circulation amount of the nanobubble cleaning liquid WnB.
  • a pipe r2 through which the stored nano-bubble cleaning liquid WnB passes is arranged.
  • a pump P2 that determines the flow rate of the nanobubble cleaning liquid WnB is provided in the pipe r2.
  • a drain pipe rx is provided in the cleaning tank 14. Further, the cleaning tank 14 may be provided with a return pipe r3 through which the short-lived bubble cleaning liquid WBs flows up to the storage tank 16 and can be used when the cleaning liquid W is circulated and used.
  • the return pipe r3 is provided with a pump P3 that determines the amount of return.
  • a second bubble monitor 22 may also be provided in the return pipe r3.
  • the cleaning liquid W is supplied to the fine bubble generator 10 from a cleaning water supply source (not shown).
  • the cleaning liquid W is supplied to the storage tank 16 once, and the cleaning liquid W is supplied from the stored water 16 to the fine bubble generator 10 by the pump P1.
  • a gas supply source Gas is connected to the fine bubble generator 10, and nanobubbles nB are generated in the cleaning liquid W to generate nanobubble cleaning liquid WnB.
  • the generated nano bubble cleaning liquid WnB returns to the storage tank 16. Therefore, not only the cleaning liquid W but also the nano bubble cleaning liquid WnB may be supplied to the fine bubble generator 10. Further, the nanobubble cleaning liquid WnB is stored in the storage tank 16.
  • the nanobubble cleaning liquid WnB stored in the storage tank 16 is transferred to the cleaning tank 14 through the pipe r2 by the pump P2.
  • the transferred nano bubble cleaning liquid WnB is discharged from the cleaning nozzle 14 a in the cleaning tank 14.
  • the collision processing body 26 is disposed between the cleaning nozzle 14a and the cleaning target Pro.
  • nanobubble cleaning liquid WnB collides with the collision treatment body 26 to shorten the life of the nanobubbles nB, and further part of the nanobubbles nB grows into microbubbles ⁇ B.
  • nanobubble nB has a shortened life is synonymous with “nanobubble nB undergoes a short life treatment”.
  • micro bubbles ⁇ B are generated by the impact when the collision processing body 26 collides. That is, the nanobubble cleaning liquid WnB after having collided with the collision processing body 26 becomes the cleaning liquid W containing the nanobubbles nB having a shortened life and the microbubbles ⁇ B. This is called short-lived bubble cleaning liquid WBs.
  • the short-lived air bubble cleaning liquid WBs covers the entire object to be cleaned Pro, and the nano-bubbles nB and the micro bubbles ⁇ B whose lifespan has been shortened are destroyed, so that the adhered substances of the object to be cleaned Pro can be peeled off. Further, the micro bubbles ⁇ B are generated almost immediately before contact with the cleaning target Pro. Therefore, the problem that the micro bubbles ⁇ B disappear during the transfer of the pipe r2 is also solved.
  • the collision treatment body 26 is one in which the nanobubble cleaning liquid WnB ejected from the cleaning nozzle 14a flies in space and physically collides, and it is sufficient that it has at least the collision surface 26a.
  • FIG. 3 illustrates the shape of the collision processing body 26.
  • FIG. 3 (a) shows a collision processing body 26 that has a discharge port 26o on the bottom and is configured by a cylindrical body 26t that is open at the top.
  • the nano-bubble cleaning liquid WnB discharged from the cleaning nozzle 14a collides with the inner wall 26ta and the liquid surface 26s accumulated inside, so that the diameter of the nano-bubbles nB becomes large, that is, the life thereof is shortened, and further the micro-bubbles ⁇ B are reduced. Is generated.
  • the cleaning liquid W containing the short-life processed nano bubbles nB and the micro bubbles ⁇ B, that is, the short-life bubble cleaning liquid WBs is discharged from the discharge port 26o.
  • the short-life bubble cleaning liquid WBs comes into contact with the cleaning target Pro.
  • the collision surface 26a may be a solid surface (inner wall 26ta in FIG. 3A) or a liquid surface (in FIG. 3A, liquid surface). 26s).
  • FIG. 3B shows a case where the collision surface 26a of the collision processing body 26 is formed of only solid.
  • Other shapes of the plate-like object 26f are not particularly limited as long as the plate surface 26fa becomes the collision surface 26a. That is, as long as it has the flat plate surface 26fa, the shape of the other portion may be arbitrary.
  • the nano bubble cleaning liquid WnB ejected from the cleaning nozzle 14a collides with the plate surface 26fa, so that the nano liquid nB subjected to the short life treatment and the micro bubbles are contained in the cleaning liquid W. ⁇ B is generated and becomes short-lived bubble cleaning liquid WBs. The short-life bubble cleaning liquid WBs comes into contact with the cleaning target Pro.
  • the solid collision surface 26a may be a flat surface, but may be a surface having irregularities.
  • the solid collision surface 26a may be given a motion such as rotation. This is because impact upon collision is likely to occur and micro bubbles ⁇ B are likely to be generated.
  • FIG. 3 (c) shows the interior of the collision processing body 26 that is partitioned in the vertical direction, and is formed, for example, in the shape of a honeycomb structure having openings on both sides.
  • the nano-bubble cleaning liquid WnB collides with the portion of the crosspiece (vertical wall) forming the partition, and the nanobubbles nB are subjected to a short life treatment.
  • micro bubbles ⁇ B are generated by the impact when colliding with the nano bubbles nB.
  • the nano-bubble cleaning liquid WnB becomes the short-lived bubble cleaning liquid WBs, and drops and contacts the cleaning object Pro below.
  • the height of the partition may be short or may be mesh-like.
  • FIG. 3D shows a case where the collision processing body 26 is composed of only the liquid surface 26s.
  • the cleaning target Pro is immersed in a liquid having a certain depth (which may be the cleaning liquid W or the short-lived bubble cleaning liquid WBs), and the nano bubble cleaning liquid WnB is jetted from above by the cleaning nozzle 14a.
  • the nanobubble cleaning liquid WnB that has collided with the liquid surface 26s undergoes a short life treatment.
  • micro bubbles ⁇ B are generated by the impact when they partially collide with the nano bubbles nB.
  • the chemical solution remaining on the surface of the object to be cleaned Pro may constitute the collision processing body 26.
  • FIG. 4 shows a case where the end of the collision processing body 26 is immersed in the short-life bubble cleaning liquid WBs. From the examples described below, it was found that the nanobubble cleaning liquid WnB, when hitting a wall and flowing down, generated a large number of microbubbles ⁇ B from the flowing-down liquid. Further, in the nanobubble cleaning liquid WnB, when the collision speed is slow, the microbubbles ⁇ B are generated only near the liquid surface. On the other hand, when the nanobubble cleaning liquid WnB hits the wall and flows down, it was confirmed that the microbubbles ⁇ B were generated deep in the water.
  • FIG. 4 shows a configuration in which the end of the collision processing body 26 is immersed in the liquid surface.
  • the nano bubble cleaning liquid WnB collides with the collision processing body 26 and then flows down through the collision processing body 26 to reach the cleaning liquid W (short-lived bubble cleaning liquid WBs) in which the cleaning target Pro is immersed. Then, micro bubbles ⁇ B are generated from the entry point to a certain depth.
  • the collision processing body 26 is immersed in the short-life bubble cleaning liquid WBs with a tilt of 45 degrees, but it may be immersed vertically (90 degrees), and the tilt angle is not limited.
  • the cleaning object Pro need only be arranged at the depth where the micro bubbles ⁇ B are generated, and it is not necessary to strictly control the depth from the liquid surface. As a result, it is possible to obtain the fine bubble cleaning device 1 that is extremely easy to adjust. Further, the nano-bubble cleaning liquid WnB collides with the collision processing body 26 to become the short-lived bubble cleaning liquid WBs, and then, the damage to the cleaning target Pro is far less than that when the nano-bubble cleaning liquid WnB drops and collides with the cleaning target Pro. Small. Therefore, it is almost unnecessary to consider the damage to the cleaning target Pro during cleaning. Therefore, even the object Pro to be cleaned that has been subjected to ultrafine processing can be safely cleaned.
  • the collision processing body 26 is disposed between the object to be cleaned Pro and the cleaning nozzle 14a, and when the nano bubble cleaning liquid WnB discharged from the cleaning nozzle 14a collides, the physical force is applied to the nano bubble cleaning liquid. It is given to WnB.
  • the fine bubble cleaning device 1 may include a control device 30.
  • the control device 30 receives the signals S1 and S2 from the first bubble monitor 20 and the second bubble monitor 22, and in order to adjust the production amount of bubbles, an instruction signal CB0 to the fine bubble generation device 10 and a pump P1, The instruction signals CP1, CP2, CP3 to P2, P3 are transmitted.
  • Fig. 5 shows the structure of the experiment. Ion-exchanged water was prepared as the cleaning liquid W.
  • the cleaning liquid W is poured into the storage tank 16 and is supplied to the fine bubble generation device 10 by the circulation pipe r1 provided in the storage tank 16.
  • Buvitas HYK-32D manufactured by Ligaric was used as the fine bubble generator 10.
  • a gas (oxygen) supply source Gas was connected to the fine bubble generator 10 to generate a nano bubble cleaning liquid WnB having an oxygen concentration of 18 ppm. Further, the fine bubble generator 10 can generate a nano bubble cleaning liquid WnB by flowing 700 mL of gas for 1 minute.
  • the nano-bubble cleaning liquid WnB stored in the storage tank 16 was sent to the pressurizing device 94, pressurized, and sent to the cleaning nozzle 14a.
  • a stainless pressure container 2.5 L TA100N was used as the pressure device 94. The pressurizing device 94 adjusted the discharge pressure.
  • a nozzle (TPU650033 manufactured by Spraying Systems Co., Ltd.) having an injection angle of 65 degrees was used.
  • a graduated cylinder 96 having a diameter of about 70 mm was used as a discharge target.
  • Nanosight LM-10 manufactured by Malvern was used as the bubble concentration measuring device 98. This uses a red laser (wavelength: 638 nm) and was able to detect bubbles having a bubble diameter of 30 to 1000 nm.
  • the procedure of the experiment was as follows. Into the graduated cylinder 96, 1 L of the nano bubble cleaning liquid WnB generated by the fine bubble generator 10 was placed. Next, the nano bubble cleaning liquid WnB was discharged from the cleaning nozzle 14a at a predetermined pressure. The nano bubble cleaning liquid WnB collides with the inner wall and the liquid surface of the graduated cylinder 96. The cleaning liquid W after the collision was collected from the vicinity of the liquid surface of the measuring cylinder 96, and the distribution of bubbles was measured by the bubble concentration measuring device 98.
  • the measurement results are shown in FIG.
  • the horizontal axis represents the bubble diameter (nm), and the vertical axis represents the concentration (10 6 cells / mL).
  • the line A indicates the distribution of the nano bubble cleaning liquid WnB generated in the fine bubble generator 10 before being discharged to the graduated cylinder 96. There is a main region of distribution from 80 nm to 150 nm.
  • the line B is the bubble distribution of the cleaning liquid W after collision when discharged at a pressure of 0.1 MPa. It can be seen that the distribution becomes broader than that of the line A, and the distribution around 300 nm is larger than that before the collision. As described above, the nanobubble nB has a large bubble diameter, so that the stability is destroyed and the life of the nanobubble nB is shortened.
  • FIG. 7A shows a photograph when pure water is put into the graduated cylinder 96 and then the pure water is discharged from the cleaning nozzle 14a.
  • FIG. 7B shows a photograph when the nano bubble cleaning liquid WnB is put into the measuring cylinder 96 and then the nano bubble cleaning liquid WnB is ejected from the cleaning nozzle 14a. That is, FIG. 7B shows the state of line B in FIG.
  • the area C in FIG. 7A and the area D in FIG. 7B are both areas where micro bubbles ⁇ B are generated.
  • the micro bubbles ⁇ B are generated by the impact when the liquid is discharged from the cleaning nozzle 14a and collides with the inner wall of the measuring cylinder 96 and the liquid surface.
  • the portion in which micro bubbles ⁇ B are generated appears cloudy on the photograph.
  • area C and area D area D is observed larger. That is, in the case of the nano bubble cleaning liquid WnB (FIG. 7 (b)), more micro bubbles ⁇ B are generated as compared with the pure water (FIG. 7 (a)). It is considered that this is because not only the micro bubbles ⁇ B due to the impact at the time of collision but also the nano bubbles nB grew into the micro bubbles ⁇ B.
  • the nano-bubble cleaning liquid WnB has an initial dissolved gas amount of 18 ppm, which is higher than pure water and higher than the saturation concentration. Therefore, the nano-bubble cleaning liquid WnB becomes a bubble of the dissolved gas when ejected (pressurized to depressurized) to make the droplet finer, and the nano-bubble nB in the droplet whose pressure balance is broken when ejected. It is considered that the droplet is made smaller when a part of it becomes large and breaks.
  • pure water has a small amount of dissolved gas and thus has larger droplets after being ejected than the nano-bubble cleaning liquid WnB, colliding with the liquid surface and entraining air on the liquid surface to form millibubbles.
  • FIG. 8A shows a spray height from the liquid surface of 40 mm
  • FIG. 8B shows a spray height from the liquid surface of 100 mm
  • FIG. 8C shows a spray height from the liquid surface. Is 120 mm
  • FIG. 8D shows a case where the spray height from the liquid surface is 180 mm.
  • the spray pressure was 0.3 MPa.
  • the nanobubble cleaning liquid WnB having an oxygen concentration of 18 ppm was used.
  • micro bubbles ⁇ B were generated from the liquid surface to a deep position at the portion which hits the wall surface and flows down the wall surface to reach the liquid surface (H part). From this, it was found that the microbubbles ⁇ B can be generated at a deep position by causing the nanobubble cleaning liquid WnB to once collide with the wall surface and allowing the colliding surface to flow down and reach the liquid surface.
  • the spray striking force has an appropriate strength for the pattern, and it is considered that the cleaning effect is enhanced by the generation of the micro bubbles ⁇ B.
  • FIG. 9 shows a state where the spray hitting force is small (spray height) by using dissolved water amount of 32 ppm (the dissolved oxygen amount was increased from the above experiment) and purified water of dissolved oxygen amount of 7 ppm (normal water oxygen concentration).
  • the result of analyzing with a high-speed camera what kind of bubbles are generated after colliding with the liquid surface at 180 mm) is shown.
  • the dissolved oxygen amount of 32 ppm was described as "oxygen UFB water”, and the purified water was shown as "purified water”.
  • the horizontal axis represents the bubble diameter ( ⁇ m), and the vertical axis represents the number (number / in-plane).
  • in-plane refers to the inside of one screen of the high-speed camera. It was found from the graph that when the oxygen content was high, the amount of microbubbles ⁇ B generated was much higher than when the oxygen content was low (approximately 27 times per unit volume). It is considered that this is because cavitation bubbles were generated with the dissolved gas and the nano bubbles nB as nuclei.
  • the nanobubble cleaning liquid WnB having a high dissolved gas concentration generates a large amount of microbubbles ⁇ B without strongly colliding with the liquid surface, and the short-lived bubble cleaning liquid WBs expected to have a cleaning effect is generated. .
  • FIG. 10 shows the temperature change when the nano-bubble cleaning liquid WnB was applied to the slope, and the temperature was measured by attaching a thermocouple to the back surface of the silicon substrate.
  • FIG. 10A is a side view conceptual diagram of the experimental apparatus.
  • the cleaning nozzle 14a (jet angle 65 °) was arranged at a point 120 mm away from the inclined surface, and the nanobubble cleaning liquid WnB with purified water was sprayed at a pressure of 0.3 MPa.
  • the temperatures at three points on the inclined surface were examined by attaching thermocouples to the back surface of the silicon substrate.
  • the ejection center is represented by "o center”
  • the point 25 mm above the ejection center is represented by “ ⁇ upper part”
  • the point 25 mm below the ejection center is represented by "x lower part”.
  • FIG. 10 (b) shows the temperature at each point in the case of the nano bubble cleaning liquid WnB using purified water.
  • the horizontal axis is the elapsed time (seconds: described as “sec”) after the start of measurement after ejection, and the vertical axis is the temperature (° C.).
  • the temperature changes in the central part (marked with ⁇ ) and the lower part (marked with x) are almost the same.
  • the upper part (marked by ⁇ ) the temperature was constant for a few seconds after the start of the ejection measurement and after 180 seconds, the central portion, the upper portion and the lower portion of the ejection were constant and stable.
  • the upper part is shown as “ ⁇ Water CH1”
  • the central part is shown as “ ⁇ Water CH2”
  • the lower part is shown as “ ⁇ Water CH3”.
  • FIG. 10C shows the result in the case of the nano bubble cleaning liquid WnB containing 32 ppm of oxygen.
  • the upper part (marked with ⁇ ) was the lowest, and the central part (marked with ⁇ ) was higher by about 0.7 ° C.
  • the lower part (marked with x) was clearly higher than the center part (marked with ⁇ ) by about 1 ° C., and these relationships were stable. It is considered that this is because the nano-bubble cleaning liquid WnB collides with the slope to become the short-lived bubble cleaning liquid WBs having the micro bubbles ⁇ B, and heat is generated at the point where the micro bubbles ⁇ B are destroyed after a lapse of the subsequent flow time.
  • FIG. 11 shows an embodiment in which the collision processing body 26 is composed of only the liquid surface 26s (see FIG. 3D).
  • the object to be cleaned Pro "GKE cleaning indicator (Distributor by gke: Meiyu Co. Ltd.)" was used. This is composed of sheets with pseudo stains L1 to L4. Each of the sheets L1 to L4 has different types of pseudo stains formed on the base material. Since it is an indicator for various detergency, neither of the sheets can be completely cleaned with water.
  • This pseudo stain is a stain that can be taken with temperature, or a stain that can be taken with the pH of the wash water.
  • L2 dirty that can be taken at pH
  • the experimental apparatus fixed the object to be cleaned Pro (GKE cleaning indicator) to the bottom of the container 40 and filled the container 40 with 10 mL of the alkaline cleaning liquid 42.
  • the depth from the liquid surface of the container 40 to the cleaning object Pro was about 1 mm.
  • the pH of the alkaline cleaning liquid 42 was 13 or more at the concentration usually used, whereas the alkaline cleaning liquid 42 was diluted 100 times to weaken the dissolving power, and the pH was about 10-12.
  • the spray nozzle 14a (TPU650017 manufactured by Spraying Systems Co., Ltd.) was set at a position 100 mm away from the cleaning target Pro.
  • FIG. 12A is an enlarged view of FIG. 8B
  • FIG. 12B is a partially enlarged view thereof.
  • FIG. 8B shows the case where the spray height from the liquid surface is 100 mm. The point 1 mm below the sprayed liquid surface is the portion indicated by the arrow in FIG.
  • Micro bubble ⁇ B was generated in this part (near collision part F), and it was a region where the direct spray hitting force did not hit. That is, in FIG. 11A, below 1 mm from the liquid surface, the spraying force of the spray is not directly applied, and the sprayed nano-bubble cleaning liquid WnB has a thickness of 1 mm when it hits the generation area of micro bubbles generated by cavitation from the interface. It can be said that this is a region in which the short-life cleaning liquid WBs is obtained by subjecting the water of the above-mentioned water to the collision processing body 26 to undergo the short-life processing.
  • the nano bubble cleaning liquid WnB using oxygen and purified water were applied to the liquid surface from the nozzle 14a at a spray pressure of 0.5 MPa.
  • the liquid level of the alkaline cleaning liquid 42 is gradually increased by spraying, and the influence of the spray hitting force on the object to be cleaned Pro (GKE cleaning indicator) is further reduced. Since the nano-bubble cleaning liquid WnB is also a mixture of purified water with oxygen nano-bubbles, the pH in the container 40 becomes thin with the passage of time. The spray time was 2 minutes.
  • FIG. 13 shows the result.
  • 13A and 13B show the case of the nanobubble cleaning liquid WnB
  • FIGS. 13C and 13D show the case of purified water.
  • 13A and 13D are photographs of the sheet in the container 40 immediately after the spraying is stopped.
  • 13B and 13D are enlarged views of the soiled portion of the sheet after cleaning.
  • 13 (b) and 13 (d) are the stain components after cleaning. This image was subjected to image processing with image processing software (color spatial plotter), and the intensity of green and frequency analysis were performed.
  • FIG. 14 shows the result.
  • FIG. 14A shows the case where the nanobubble cleaning liquid WnB is used
  • FIG. 14B shows the case where purified water is used.
  • the horizontal axis represents green intensity
  • the vertical axis j represents frequency.
  • the nano-bubble cleaning liquid WnB was used, the average intensity of green color was 0.590, whereas that of purified water was 0.621. That is, it was possible to reduce the intensity of the green color by using the nano bubble cleaning liquid WnB. This is a result of removing the green pseudo stain, and it was confirmed that the nanobubble cleaning liquid WnB has a cleaning power.
  • the nano-bubble cleaning liquid WnB As described above, by colliding the nano-bubble cleaning liquid WnB with the collision treatment body 26, it is possible to treat the nano-bubbles nB for a short life and further increase the generation amount of the micro-bubbles ⁇ B. Further, even if the nano-bubble cleaning liquid WnB collides with the collision processing body 26, many millimeter bubbles are not generated and the cleaning power is not impaired.
  • micro-bubble cleaning device can be suitably used in the cleaning process of semiconductors and electronic devices. Further, it can be suitably used for cleaning the inner wall of piping and the like.
  • Micro Bubble Cleaner 10 Micro Bubble Generator 14 Cleaning Tank 14a Cleaning Nozzle 16 Storage Tank 20 First Bubble Monitor 22 Second Bubble Monitor 26 Collision Processing Body 26a Collision Surface 26o Discharge Port 26t Cylindrical Body 26ta Inner Wall 26s Liquid Surface 26f Plate-like Object 26fa Plate surface 30
  • Control device 40 Container 42 Alkaline cleaning liquid 44 Dirt component 70 Chemical liquid device 71 Disk 72 Chemical liquid nozzle 73 Chemical liquid tank 74 Pump 75 Filter 90 Cleaning liquid tank 92 Oxygen cylinder 94 Pressurizing device 96 Messy cylinder 98 Bubble concentration measuring device W Cleaning liquid nB nano bubbles ⁇ B micro bubbles WnB nano bubbles cleaning liquid Gas gas supply source WBs short life bubble cleaning liquid Pro to be cleaned r1 circulation pipe r2 pipe rx drain pipe r3 return pipe P1 pump P2 Pump P3 Pump

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Abstract

The present invention addresses the problem that, when it is desired to utilize fine bubbles for cleaning a semiconductor or an electronic device, it may not be possible to effectively utilize the energy upon destruction of fine bubbles because nano-bubbles are stable and have a long lifetime, and microbubbles mostly disappear when transported by piping. This fine-bubble cleaning device is characterized by comprising: a fine-bubble generation device which causes at least nano-order fine bubbles to be generated in a cleaning solution to generate a nanobubble cleaning solution; a cleaning nozzle for ejecting the nanobubble cleaning solution toward an object to be cleaned; and a collision processing body disposed between the cleaning nozzle and the object to be cleaned. The fine-bubble cleaning device generates micro bubbles just before the micro bubbles are contacted with the object to be cleaned, making it possible to perform effective cleaning.

Description

微細気泡洗浄装置及び微細気泡洗浄方法Fine bubble cleaning device and fine bubble cleaning method
　本発明は微細気泡を用いた洗浄装置および洗浄方法に係るものである。 The present invention relates to a cleaning device and a cleaning method using fine bubbles.
　現在、半導体や液晶の電子デバイスでは、薬液でレジストを溶解したり、エッチング加工をした後に、薬液成分の置換と同時に付着したり残存する異物を除去するため、純水などを用いた洗浄が行われている。 Currently, electronic devices such as semiconductors and liquid crystals are cleaned with pure water to dissolve the resist with a chemical solution or perform etching processing, and then remove foreign substances that adhere to or remain at the same time as the chemical solution components are replaced. It is being appreciated.
　異物の除去能力を向上し確保するためには、物理力を加えることが重要である。具体的には、ブラシを用いる、気体と液体を同時に噴出させて液滴にする（２流体洗浄）、超音波で液に振動を加える、といった方法が多用される。更に液中にある異物がデバイス表面に再付着するのを防止するために、異物の表面電位を制御することが行われている。異物の表面電位の制御は、液中のｐＨをアルカリ側にコントロールすることで行われている。 In order to improve and secure the ability to remove foreign substances, it is important to add physical force. Specifically, a method of using a brush, a method of jetting a gas and a liquid at the same time to form a droplet (two-fluid cleaning), and a method of vibrating the liquid with ultrasonic waves are widely used. Further, in order to prevent the foreign matter in the liquid from reattaching to the device surface, the surface potential of the foreign matter is controlled. The surface potential of the foreign matter is controlled by controlling the pH of the liquid to the alkaline side.
　特に、センサーなどの複雑な形状のデバイスや、究極まで薄膜化された電子デバイスを十分に洗浄するためには、液自体が細部まで浸透した上で溶解や物理力を発揮する必要がある。その方法の一つとして水素やオゾンのガスを溶解した機能水が有効と考えられる。しかし、水素は、溶解量が高々１ｐｐｍ程度しか溶解しない。また、オゾンは金属材料向けに使用が困難である。結果、水素ガス、オゾンガス共に洗浄能力が不十分であった。 In particular, in order to sufficiently clean devices with complicated shapes such as sensors, and electronic devices that are made to be the ultimate thin film, it is necessary for the liquid itself to penetrate into details and then exert its dissolution and physical strength. As one of the methods, it is considered that functional water in which hydrogen or ozone gas is dissolved is effective. However, the dissolved amount of hydrogen is at most about 1 ppm. Also, ozone is difficult to use for metallic materials. As a result, the cleaning ability was insufficient for both hydrogen gas and ozone gas.
　近年、新しい洗浄方法の一つとして、マイクロ・ナノバブル（以後「ファインバブル：ＦＢ」と呼ぶ。）を混入した純水や液を用いた洗浄方法が提案されている。マイクロバブルを用いた洗浄では、マイクロバブルの物理的な衝撃やバブルが圧壊した時のエネルギーを利用して、電子デバイス表面の付着物を除去している（特許文献１）。 In recent years, as one of the new cleaning methods, a cleaning method using pure water or liquid mixed with micro / nano bubbles (hereinafter referred to as “fine bubbles: FB”) has been proposed. In cleaning using microbubbles, the physical impact of the microbubbles and the energy when the bubbles are crushed are used to remove the deposits on the surface of the electronic device (Patent Document 1).
　しかし、ＦＢの中でもナノオーダーの大きさの気泡は安定しており寿命が数か月にもわたる。そのため、被洗浄物の表面で、タイミングよく圧壊するのは期待できない。そこで、予め寿命が短くなるような処理（衝撃寿命）を気泡に与え、被洗浄物の表面で圧壊しやすくするといった提案もなされている（特許文献２）。 However, among the FBs, bubbles of nano-order size are stable and have a life span of several months. Therefore, it cannot be expected that the surface of the object to be cleaned will be crushed in a timely manner. Therefore, a proposal has also been made that a treatment for shortening the life (impact life) is given to the bubbles in advance so that the bubbles are easily crushed on the surface of the object to be cleaned (Patent Document 2).
　上記では、気泡の消滅を「圧壊」と記載したが、通常、「圧壊」は気泡が圧縮、すなわち気泡径が小さくなって破壊することである。洗浄時に利用できるエネルギーは、気泡径が大きくなって破壊する場合も含むため、以下では気泡の消滅を「破壊」と記載する。 In the above, the disappearance of bubbles is described as "crushing", but "crushing" usually means that the bubbles are compressed, that is, the bubble diameter becomes smaller and they are destroyed. Since the energy that can be used during cleaning includes the case where the bubble diameter is increased and the bubble is destroyed, the disappearance of the bubble is described as "destroy".
特開２００８－９８４３０号公報JP, 2008-98430, A 特許第６２５２９２６号公報Japanese Patent No. 6252926
　ファインバブルには、１ｎｍから１μｍ未満のナノバブル（以後「ナノ気泡」と呼ぶ。）と１μｍから１００μｍまでのマイクロバブル（以後「マイクロ気泡」と呼ぶ。）に分けられる。このうち、ナノ気泡の寿命は数か月と長いが、マイクロ気泡の寿命はナノ気泡と比較して非常に短いことが分かった。 Fine bubbles are divided into nano bubbles of 1 nm to less than 1 μm (hereinafter referred to as “nano bubbles”) and micro bubbles of 1 μm to 100 μm (hereinafter referred to as “micro bubbles”). Among them, it was found that the lifetime of nano bubbles is as long as several months, but the lifetime of micro bubbles is much shorter than that of nano bubbles.
　つまり、マイクロ気泡は生成され配管を通って、被洗浄物に到達するまでに、かなりの数が自然破壊してしまう。さらに、気泡を形成していたガスの溜りにより、配管内の送液に支障をきたすこともあった。 In other words, a large number of micro bubbles are generated and spontaneously destroyed by the time they reach the object to be cleaned through the pipe. Further, the accumulation of the gas that formed the bubbles may hinder the liquid transfer in the pipe.
　したがって、上記のように、洗浄液中のマイクロ気泡が配管による移送の間に破壊して消滅してしまい、被洗浄物に到達できなければ、マイクロ気泡の破壊の際のエネルギーを有効に活用できないという課題が生じていた。 Therefore, as described above, the micro bubbles in the cleaning liquid are destroyed and disappear during the transfer by the pipe, and unless the object to be cleaned can be reached, the energy at the time of the destruction of the micro bubbles cannot be effectively utilized. There were challenges.
　本発明は上記の課題に鑑みて想到されたものである。後述するファインバブル洗浄液のノズル噴射により気泡径が大きくなるという現象から、特許文献２の気泡自発圧壊装置として洗浄ノズルと衝突処理体の組合せが好適であることを見出した。さらに、洗浄ノズルと衝突処理体の組合せを被洗浄物に供給する直前に設けるという発明を見出した。これにより、ファインバブルのうち、マイクロオーダーの微細気泡については、被洗浄物の近傍で発生させ、ファインバブルの破壊の際のエネルギーを有効に活用して洗浄能力を向上させる洗浄装置を提供するものである。 The present invention was conceived in view of the above problems. From the phenomenon that the bubble diameter increases due to the nozzle injection of the fine bubble cleaning liquid described later, it has been found that the combination of the cleaning nozzle and the collision processing body is suitable as the bubble spontaneous collapse device of Patent Document 2. Furthermore, the inventors have found an invention in which a combination of a cleaning nozzle and a collision processing body is provided immediately before being supplied to a cleaning target. Thus, of the fine bubbles, micro-order fine bubbles are generated in the vicinity of the object to be cleaned, and a cleaning device is provided that effectively utilizes the energy at the time of destruction of the fine bubbles to improve the cleaning capability. Is.
　より具体的に本発明に係る微細気泡洗浄装置は、
　洗浄液中に少なくともナノオーダーの微細気泡を発生させ、ナノ気泡洗浄液を生成する微細気泡発生装置と、
　前記ナノ気泡洗浄液を被洗浄物に向かって吐出する洗浄ノズルと、
　前記洗浄ノズルと前記被洗浄物の間に設けられた衝突処理体を有することを特徴とする。 More specifically, the fine bubble cleaning device according to the present invention,
A micro-bubble generator that generates at least nano-order micro bubbles in the cleaning liquid to generate nano-bubble cleaning liquid,
A cleaning nozzle for ejecting the nano-bubble cleaning liquid toward the object to be cleaned,
It has a collision processing body provided between the cleaning nozzle and the object to be cleaned.
　本発明に係る微細気泡洗浄装置は、ナノ気泡を被洗浄物に吐出する前に衝突処理体に一度当てることで、ナノ気泡をマイクロ気泡に変化させる。すなわち、被洗浄物の直前でナノ気泡からマイクロ気泡を生成し、ナノ気泡とマイクロ気泡を被洗浄物に供給する。 The micro-bubble cleaning device according to the present invention changes the nano-bubbles into micro-bubbles by hitting the nano-bubbles once on the collision-treated body before ejecting the nano-bubbles onto the object to be cleaned. That is, micro bubbles are generated from the nano bubbles just before the object to be cleaned, and the nano bubbles and the micro bubbles are supplied to the object to be cleaned.
　このようにすることで、洗浄液の移送の際にマイクロ気泡が消滅してしまうことを回避することができる。結果、ファインバブルの破壊の際のエネルギーを有効に活用して洗浄能力を向上させることができる。 By doing this, it is possible to avoid the disappearance of micro bubbles during the transfer of the cleaning liquid. As a result, it is possible to effectively utilize the energy when the fine bubbles are destroyed and improve the cleaning ability.
本発明に係る微細気泡洗浄装置の構成を示す図である。It is a figure which shows the structure of the microbubble cleaning apparatus which concerns on this invention. 洗浄槽の内部の詳細を示す図である。It is a figure which shows the detail inside the cleaning tank. 衝突処理体の具体例を示す図である。It is a figure which shows the specific example of a collision process body. 衝突処理体の具体例を示す図である。It is a figure which shows the specific example of a collision process body. 実施例の装置構成を示す図である。It is a figure which shows the apparatus structure of an Example. 実施例の結果を示す気泡径の分布図である。It is a distribution diagram of the bubble diameter which shows the result of an Example. 実施例の実験を示す写真である。It is a photograph which shows an experiment of an example. スプレー高さを変更した場合の実験結果を示す写真である。It is a photograph which shows an experimental result when changing spray height. 溶存酸素量３２ｐｐｍと溶存酸素量７ｐｐｍの精製水が、スプレー打力の小さい状態（スプレー高さ１８０ｍｍ）で液面に衝突した後にどのような気泡が発生するかを高速度カメラで分析した結果を示す。A high-speed camera analyzes the results of what kind of bubbles are generated after purified water with a dissolved oxygen content of 32 ppm and a dissolved oxygen content of 7 ppm collides with the liquid surface in a state where the spray force is small (spray height 180 mm). Show. 斜面にナノ気泡洗浄液を当てた時の温度変化を熱電対で測定した結果を示すグラフである。It is a graph which shows the result of having measured the temperature change when a nano-bubble cleaning liquid is applied to the slope with a thermocouple. 衝突処理体を液体にした場合の効果を確認する実施例を行った構成を示す図である。It is a figure which shows the structure which performed the Example which confirms the effect at the time of making a collision process body into a liquid. 液面１ｍｍ下の状態を示す図である。図８（ｂ）の拡大図である。It is a figure which shows the state below 1 mm of liquid level. It is an enlarged view of FIG.8 (b). ナノ気泡洗浄液と精製水を用いた場合の結果を示す写真である。It is a photograph which shows the result at the time of using a nano bubble cleaning liquid and purified water. 図１３の結果を画像処理した結果を示すグラフである。14 is a graph showing the result of image processing of the result of FIG. 13.
　以下に本発明に係る微細気泡洗浄装置および方法について図面を用いながら説明を行う。本発明に係る微細気泡洗浄装置１は、主としてフォトリソグラフィによって形成される半導体や電子部品の薬液処理工程や洗浄工程で用いられる。微細気泡洗浄装置１は、これらの表面に付着した付着物を除去したり、薬液成分を洗浄水と置き換えることで洗浄を行う。また、微細気泡洗浄装置１は、送液配管中の内壁の洗浄に用いることもできる。 The following will describe the fine bubble cleaning apparatus and method according to the present invention with reference to the drawings. The fine bubble cleaning apparatus 1 according to the present invention is mainly used in a chemical treatment process and a cleaning process of semiconductors and electronic parts formed by photolithography. The fine bubble cleaning device 1 performs cleaning by removing deposits adhering to these surfaces and replacing chemical liquid components with cleaning water. The fine bubble cleaning device 1 can also be used for cleaning the inner wall in the liquid supply pipe.
　以下の説明は本発明の一実施形態を説明するものであり、本発明は以下の説明に限定されるものではない。つまり、以下の実施形態は、本発明の主旨を逸脱しない限りにおいて、改変することができる。 The following description describes one embodiment of the present invention, and the present invention is not limited to the following description. That is, the following embodiments can be modified without departing from the gist of the present invention.
　図１に本発明に係る微細気泡洗浄装置１の構成について示す。本発明に係る微細気泡洗浄装置１は、微細気泡発生装置１０と、洗浄槽１４とを有する。洗浄槽１４内には、被洗浄物Ｐｒｏが載置されている。また、洗浄槽１４内には、洗浄ノズル１４ａと、衝突処理体２６も配置される。また、微細気泡洗浄装置１は、貯留槽１６を有していてもよい。 FIG. 1 shows the configuration of a fine bubble cleaning device 1 according to the present invention. The fine bubble cleaning device 1 according to the present invention includes a fine bubble generating device 10 and a cleaning tank 14. An object to be cleaned Pro is placed in the cleaning tank 14. Further, a cleaning nozzle 14 a and a collision processing body 26 are also arranged in the cleaning tank 14. Further, the fine bubble cleaning device 1 may have a storage tank 16.
　微細気泡発生装置１０は洗浄液Ｗ中に少なくとも気泡径がナノオーダー（１ｎｍ以上１μｍ未満）のナノ気泡ｎＢを発生させ、ナノ気泡洗浄液ＷｎＢを生成する装置である。なお、ナノ気泡洗浄液ＷｎＢには、気泡径がミクロンオーダー（１μｍ以上１００μｍ以下）のマイクロ気泡μＢを含んでいてもよい。しかし、微細気泡発生装置１０の地点で、マイクロ気泡μＢが洗浄液Ｗ中に混入していても、洗浄槽１４に移送される間にかなりの部分のマイクロ気泡μＢは消滅してしまう。 The fine bubble generator 10 is a device that generates nano bubbles nB having a bubble diameter of at least nano-order (1 nm or more and less than 1 μm) in the cleaning liquid W to generate the nano bubble cleaning liquid WnB. The nanobubble cleaning liquid WnB may include microbubbles μB having a diameter of micron order (1 μm or more and 100 μm or less). However, even if the micro bubbles μB are mixed in the cleaning liquid W at the point of the fine bubble generator 10, a considerable portion of the micro bubbles μB disappear while being transferred to the cleaning tank 14.
　洗浄液Ｗは、純水、イオン交換水等が好適に利用できる。しかしその他の極性溶媒や非極性溶媒を利用してもよい。洗浄液Ｗは、図示していない洗浄水供給源から供給される。ナノ気泡ｎＢは、空気であってよいが、Ｎ２（窒素）、Ｏ２（酸素）、Ｈ２（水素）、Ａｒ（アルゴン）、Ｘｅ（キセノン）、Ｏ３（オゾン）を単独若しくは複数種の混合ガスとして用いてもよい。 As the cleaning liquid W, pure water, ion-exchanged water, or the like can be preferably used. However, other polar solvents or non-polar solvents may be used. The cleaning liquid W is supplied from a cleaning water supply source (not shown). The nano bubbles nB may be air, but N 2 (nitrogen), O 2 (oxygen), H 2 (hydrogen), Ar (argon), Xe (xenon), and O 3 (ozone) may be used alone or in combination. It may be used as a mixed gas of.
　特に被洗浄物Ｐｒｏから有機材料を膨潤させて溶解し除去する場合には、Ｎ２（窒素）、Ｏ２（酸素）、Ｈ２（水素）、Ｏ３（オゾン）を用いることにより、酸化還元の効果が得られる。なお、空気以外の気体を利用する際は、気体供給源Ｇａｓが設けられてもよい。 In particular, when the organic material is swollen, dissolved and removed from the object Pro to be cleaned, redox is performed by using N 2 (nitrogen), O 2 (oxygen), H 2 (hydrogen), and O 3 (ozone). The effect of is obtained. A gas supply source Gas may be provided when using a gas other than air.
　洗浄槽１４は、後述する短寿命気泡洗浄液ＷＢｓと被洗浄物Ｐｒｏを接触させる容器である。接触させるとは、被洗浄物Ｐｒｏに短寿命気泡洗浄液ＷＢｓを吹き付けたり（吐出：シャワーも含む）、被洗浄物Ｐｒｏを短寿命気泡洗浄液ＷＢｓ中に浸漬させる（ディップ）といった方法を含む。 The cleaning tank 14 is a container for bringing the short-life bubble cleaning liquid WBs, which will be described later, into contact with the cleaning target Pro. The contacting includes a method of spraying the short-lived bubble cleaning liquid WBs on the cleaning target Pro (discharging: also including a shower), and immersing the cleaning target Pro in the short-life bubble cleaning liquid WBs (dip).
　図２には、洗浄槽１４の内部をより具体的に示す。洗浄槽１４には、すでに説明したように、洗浄ノズル１４ａと衝突処理体２６および被洗浄物Ｐｒｏが配置されている。被洗浄物Ｐｒｏはフォトリソグラフィで作製される半導体基板若しくは電子デバイスで、露光を終了したものが代表例として例示できる。 FIG. 2 shows the inside of the cleaning tank 14 more specifically. In the cleaning tank 14, as described above, the cleaning nozzle 14a, the collision processing body 26, and the cleaning target Pro are arranged. The object to be cleaned Pro is a semiconductor substrate or an electronic device produced by photolithography, and one that has been exposed can be illustrated as a typical example.
　洗浄槽１４には、露光が終わった被洗浄物Ｐｒｏを薬液処理する薬液装置７０が設けられていてもよい。薬液装置７０は、被洗浄物Ｐｒｏが吸引固定されるディスク７１と、薬液を被洗浄物Ｐｒｏに吐出する薬液ノズル７２と、薬液ノズル７２に薬液を供給する薬液タンク７３、およびポンプ７４、フィルタ７５で形成される。なお、ここで薬液処理とは、現像が終了した被洗浄物Ｐｒｏからレジストを除去する処理の一種をいう。 The cleaning tank 14 may be provided with a chemical solution device 70 that processes the exposed cleaning object Pro with a chemical solution. The chemical liquid device 70 includes a disk 71 to which the cleaning target Pro is sucked and fixed, a chemical liquid nozzle 72 that discharges the chemical liquid to the cleaning target Pro, a chemical liquid tank 73 that supplies the chemical liquid to the chemical liquid nozzle 72, a pump 74, and a filter 75. Is formed by. Here, the chemical treatment means a kind of treatment for removing the resist from the cleaning target Pro after the development.
　洗浄槽１４には、ナノ気泡洗浄液ＷｎＢを被洗浄物Ｐｒｏに向けて吐出する洗浄ノズル１４ａが配置されている。そして、洗浄ノズル１４ａと被洗浄物Ｐｒｏの間に衝突処理体２６が配置されている。ナノ気泡洗浄液ＷｎＢは、この衝突処理体２６に少なくとも一度衝突した後に、短寿命気泡洗浄液ＷＢｓとなり、被洗浄物Ｐｒｏに接触させられる。 The cleaning tank 14 is provided with a cleaning nozzle 14a for ejecting the nano-bubble cleaning liquid WnB toward the cleaning target Pro. The collision processing body 26 is disposed between the cleaning nozzle 14a and the cleaning target Pro. The nano-bubble cleaning liquid WnB becomes the short-lived bubble cleaning liquid WBs after colliding with the collision processing body 26 at least once, and is brought into contact with the cleaning target Pro.
　再度図１を参照する。以上のように、本発明に係る微細気泡洗浄装置１は、洗浄液Ｗと、微細気泡発生装置１０と、洗浄ノズル１４ａと、衝突処理体２６を主たる構成要件とする。そして、さらに貯留槽１６、第１バブルモニタ２０、第２バブルモニタ２２、制御装置３０を備えることができる。 Refer to FIG. 1 again. As described above, the fine bubble cleaning apparatus 1 according to the present invention mainly includes the cleaning liquid W, the fine bubble generating apparatus 10, the cleaning nozzle 14a, and the collision processing body 26. Further, the storage tank 16, the first bubble monitor 20, the second bubble monitor 22, and the control device 30 can be further provided.
　貯留槽１６は、微細気泡発生装置１０が生成したナノ気泡洗浄液ＷｎＢを貯留する容器である。貯留槽１６の容積は、微細気泡洗浄装置１の規模によって適宜決めることができる。第１バブルモニタ２０と第２バブルモニタ２２は、ナノ気泡洗浄液ＷｎＢ中のナノ気泡ｎＢの密度を測定する装置である。これは、レーザーを使って単位体積中のナノ気泡ｎＢの数、またはナノ気泡ｎＢの密度を測定する装置である。 The storage tank 16 is a container for storing the nano bubble cleaning liquid WnB generated by the fine bubble generating device 10. The volume of the storage tank 16 can be appropriately determined depending on the scale of the fine bubble cleaning device 1. The first bubble monitor 20 and the second bubble monitor 22 are devices that measure the density of the nano bubbles nB in the nano bubble cleaning liquid WnB. This is an apparatus for measuring the number of nanobubbles nB in a unit volume or the density of nanobubbles nB using a laser.
　第１バブルモニタ２０と第２バブルモニタ２２は、レーザー以外の手法として、配管ｒ２と帰還用配管ｒ３のある一定距離間での温度などの熱やエネルギーを測定する装置であってもよい。測定した値の差分から単位体積中のナノ気泡ｎＢの数またはナノ気泡ｎＢの密度を測定することができるからである。 The first bubble monitor 20 and the second bubble monitor 22 may be devices that measure heat or energy such as temperature between a certain distance between the pipe r2 and the return pipe r3 as a method other than laser. This is because the number of nanobubbles nB or the density of nanobubbles nB in a unit volume can be measured from the difference between the measured values.
　制御装置３０はＭＰＵ（Ｍｉｃｒｏ　Ｐｒｏｃｅｓｓｏｒ　Ｕｎｉｔ）とメモリで構成されるコンピュータが好適に利用できる。制御装置３０は、第１バブルモニタ２０と第２バブルモニタ２２に接続されている。また、さらに流量を決めるポンプ等に接続されていてもよい。なお、各ポンプはその動きを制御装置３０からの信号で制御できるように構成される。 As the control device 30, a computer including an MPU (Micro Processor Unit) and a memory can be preferably used. The control device 30 is connected to the first bubble monitor 20 and the second bubble monitor 22. Further, it may be connected to a pump or the like that determines the flow rate. Each pump is configured so that its movement can be controlled by a signal from the control device 30.
　次に各構成要素の連通関係を説明する。貯留槽１６には循環配管ｒ１が設けられる。この循環配管ｒ１には、微細気泡発生装置１０が配設されている。また、微細気泡発生装置１０には、気体供給源Ｇａｓが接続されていてもよい。循環配管ｒ１には、ナノ気泡洗浄液ＷｎＢの循環量を決めるポンプＰ１が設けられる。 Next, the communication relationship between each component is explained. The storage tank 16 is provided with a circulation pipe r1. A fine bubble generator 10 is arranged in the circulation pipe r1. Further, a gas supply source Gas may be connected to the fine bubble generator 10. The circulation pipe r1 is provided with a pump P1 that determines the circulation amount of the nanobubble cleaning liquid WnB.
　貯留槽１６と洗浄槽１４の間には、貯留されていたナノ気泡洗浄液ＷｎＢが通過する配管ｒ２が配設される。配管ｒ２には、ナノ気泡洗浄液ＷｎＢの流量を決めるポンプＰ２が設けられる。 Between the storage tank 16 and the cleaning tank 14, a pipe r2 through which the stored nano-bubble cleaning liquid WnB passes is arranged. A pump P2 that determines the flow rate of the nanobubble cleaning liquid WnB is provided in the pipe r2.
　洗浄槽１４には、ドレイン管ｒｘが設けられる。また、洗浄槽１４には、貯留槽１６までの間に短寿命気泡洗浄液ＷＢｓが流れる帰還用配管ｒ３が設けられていてもよく、洗浄液Ｗを循環使用する際に用いることができる。帰還用配管ｒ３には、帰還量を決めるポンプＰ３が設けられる。また、帰還用配管ｒ３には、第２バブルモニタ２２も設けられていてもよい。 A drain pipe rx is provided in the cleaning tank 14. Further, the cleaning tank 14 may be provided with a return pipe r3 through which the short-lived bubble cleaning liquid WBs flows up to the storage tank 16 and can be used when the cleaning liquid W is circulated and used. The return pipe r3 is provided with a pump P3 that determines the amount of return. A second bubble monitor 22 may also be provided in the return pipe r3.
　以上の構成を有する微細気泡洗浄装置１の動作について図１および図２を参照して説明する。洗浄液Ｗは、図示しない洗浄水供給源から微細気泡発生装置１０に供給される。図１では、洗浄液Ｗは、貯留槽１６に一度供給され、貯留水１６からポンプＰ１によって微細気泡発生装置１０に洗浄液Ｗが供給される場合を示している。 The operation of the fine bubble cleaning device 1 having the above configuration will be described with reference to FIGS. 1 and 2. The cleaning liquid W is supplied to the fine bubble generator 10 from a cleaning water supply source (not shown). In FIG. 1, the cleaning liquid W is supplied to the storage tank 16 once, and the cleaning liquid W is supplied from the stored water 16 to the fine bubble generator 10 by the pump P1.
　微細気泡発生装置１０には、気体供給源Ｇａｓが接続されており、洗浄液Ｗ中にナノ気泡ｎＢを生成させ、ナノ気泡洗浄液ＷｎＢを生成する。生成されたナノ気泡洗浄液ＷｎＢは、貯留槽１６に戻る。したがって、微細気泡発生装置１０には、洗浄液Ｗだけでなく、ナノ気泡洗浄液ＷｎＢが供給されていてもよい。また、貯留槽１６にはナノ気泡洗浄液ＷｎＢが貯留されてゆく。 A gas supply source Gas is connected to the fine bubble generator 10, and nanobubbles nB are generated in the cleaning liquid W to generate nanobubble cleaning liquid WnB. The generated nano bubble cleaning liquid WnB returns to the storage tank 16. Therefore, not only the cleaning liquid W but also the nano bubble cleaning liquid WnB may be supplied to the fine bubble generator 10. Further, the nanobubble cleaning liquid WnB is stored in the storage tank 16.
　貯留槽１６に貯留されたナノ気泡洗浄液ＷｎＢは、配管ｒ２中をポンプＰ２によって、洗浄槽１４に向かって移送される。移送されたナノ気泡洗浄液ＷｎＢは、洗浄槽１４内の洗浄ノズル１４ａから吐出される。洗浄ノズル１４ａと被洗浄物Ｐｒｏの間には、衝突処理体２６が配置されている。 The nanobubble cleaning liquid WnB stored in the storage tank 16 is transferred to the cleaning tank 14 through the pipe r2 by the pump P2. The transferred nano bubble cleaning liquid WnB is discharged from the cleaning nozzle 14 a in the cleaning tank 14. The collision processing body 26 is disposed between the cleaning nozzle 14a and the cleaning target Pro.
　後述する実施例でも示すように、ナノ気泡洗浄液ＷｎＢでは、衝突処理体２６に衝突することで、ナノ気泡ｎＢが短寿命化され、さらにナノ気泡ｎＢの一部がマイクロ気泡μＢに成長する。ここで「ナノ気泡ｎＢが短寿命化される」とは、「ナノ気泡ｎＢが短寿命処理を受ける」と同意である。 As will be shown in Examples described later, the nanobubble cleaning liquid WnB collides with the collision treatment body 26 to shorten the life of the nanobubbles nB, and further part of the nanobubbles nB grows into microbubbles μB. Here, "nanobubble nB has a shortened life" is synonymous with "nanobubble nB undergoes a short life treatment".
　また衝突処理体２６に衝突したときの衝撃でマイクロ気泡μＢも発生する。つまり、衝突処理体２６に衝突した後のナノ気泡洗浄液ＷｎＢは、短寿命化されたナノ気泡ｎＢと、マイクロ気泡μＢを含む洗浄液Ｗとなる。これを短寿命気泡洗浄液ＷＢｓと呼ぶ。 Also, micro bubbles μB are generated by the impact when the collision processing body 26 collides. That is, the nanobubble cleaning liquid WnB after having collided with the collision processing body 26 becomes the cleaning liquid W containing the nanobubbles nB having a shortened life and the microbubbles μB. This is called short-lived bubble cleaning liquid WBs.
　この短寿命気泡洗浄液ＷＢｓは、被洗浄物Ｐｒｏの全体を覆い、短寿命化されたナノ気泡ｎＢとマイクロ気泡μＢは、破壊することで、被洗浄物Ｐｒｏの付着物を剥離することができる。また、マイクロ気泡μＢは、被洗浄物Ｐｒｏに接触するほぼ直前に生成されている。そのため、配管ｒ２の移送の際にマイクロ気泡μＢが消滅するという課題も解決される。 The short-lived air bubble cleaning liquid WBs covers the entire object to be cleaned Pro, and the nano-bubbles nB and the micro bubbles μB whose lifespan has been shortened are destroyed, so that the adhered substances of the object to be cleaned Pro can be peeled off. Further, the micro bubbles μB are generated almost immediately before contact with the cleaning target Pro. Therefore, the problem that the micro bubbles μB disappear during the transfer of the pipe r2 is also solved.
　ところで、衝突したときの衝撃では、マイクロ気泡μＢだけでなく、気泡径が１００μｍを超えるミリ気泡も発生する。ミリ気泡が、被洗浄物Ｐｒｏの表面に付着すると、短寿命気泡洗浄液ＷＢｓの微細な部分への浸透を妨げる要因となる。しかし、後述する実施例で示されるように、ナノ気泡ｎＢを含有するナノ気泡洗浄液ＷｎＢでは、ナノ気泡ｎＢの存在が、ミリ気泡の生成を抑制するためミリ気泡は生じにくい。 By the way, not only micro bubbles μB but also millimeter bubbles with a bubble diameter of more than 100 μm are generated due to the impact of collision. When the millimeter bubbles adhere to the surface of the cleaning target Pro, it becomes a factor that prevents the short-lived bubble cleaning liquid WBs from penetrating into a fine portion. However, as shown in Examples described later, in the nanobubble cleaning liquid WnB containing the nanobubbles nB, the presence of the nanobubbles nB suppresses the generation of the millibubbles, so that the millibubbles are less likely to occur.
　衝突処理体２６は、洗浄ノズル１４ａから吐出されたナノ気泡洗浄液ＷｎＢが、空間を飛んで物理的に衝突するものであり、少なくとも衝突面２６ａを有していればよい。図３には、衝突処理体２６の形状を例示する。 The collision treatment body 26 is one in which the nanobubble cleaning liquid WnB ejected from the cleaning nozzle 14a flies in space and physically collides, and it is sufficient that it has at least the collision surface 26a. FIG. 3 illustrates the shape of the collision processing body 26.
　図３（ａ）は、底に吐出口２６ｏを有し、上方が開口した筒体２６ｔで構成された衝突処理体２６である。洗浄ノズル１４ａから吐出されたナノ気泡洗浄液ＷｎＢは、内壁２６ｔａと、内側に溜まった液面２６ｓに衝突することで、ナノ気泡ｎＢは径が大きくなり、すなわち短寿命化され、さらにマイクロ気泡μＢが生成される。 FIG. 3 (a) shows a collision processing body 26 that has a discharge port 26o on the bottom and is configured by a cylindrical body 26t that is open at the top. The nano-bubble cleaning liquid WnB discharged from the cleaning nozzle 14a collides with the inner wall 26ta and the liquid surface 26s accumulated inside, so that the diameter of the nano-bubbles nB becomes large, that is, the life thereof is shortened, and further the micro-bubbles μB are reduced. Is generated.
　そして、短寿命処理されたナノ気泡ｎＢとマイクロ気泡μＢを含む洗浄液Ｗ、すなわち短寿命気泡洗浄液ＷＢｓが、吐出口２６ｏから吐出される。短寿命気泡洗浄液ＷＢｓは、被洗浄物Ｐｒｏと接触する。 Then, the cleaning liquid W containing the short-life processed nano bubbles nB and the micro bubbles μB, that is, the short-life bubble cleaning liquid WBs is discharged from the discharge port 26o. The short-life bubble cleaning liquid WBs comes into contact with the cleaning target Pro.
　このように、衝突面２６ａ（図２参照）は、固体で形成される面（図３（ａ）では内壁２６ｔａ）であってもよいし、液体による面（図３（ａ）では、液面２６ｓ）であってもよい。 As described above, the collision surface 26a (see FIG. 2) may be a solid surface (inner wall 26ta in FIG. 3A) or a liquid surface (in FIG. 3A, liquid surface). 26s).
　図３（ｂ）は、衝突処理体２６の衝突面２６ａが固体だけで形成される場合を示す。板状物２６ｆは、板面２６ｆａが衝突面２６ａとなれば、他の形状は特に限定されない。つまり、平坦な板面２６ｆａを有していれば、他の部分の形状は任意であってよい。 FIG. 3B shows a case where the collision surface 26a of the collision processing body 26 is formed of only solid. Other shapes of the plate-like object 26f are not particularly limited as long as the plate surface 26fa becomes the collision surface 26a. That is, as long as it has the flat plate surface 26fa, the shape of the other portion may be arbitrary.
　このような構成であっても、洗浄ノズル１４ａから吐出されたナノ気泡洗浄液ＷｎＢは、板面２６ｆａに衝突することで、洗浄液Ｗ中には、短寿命処理を受けたナノ気泡ｎＢと、マイクロ気泡μＢが生成され、短寿命気泡洗浄液ＷＢｓとなる。短寿命気泡洗浄液ＷＢｓは、被洗浄物Ｐｒｏと接触する。 Even with such a configuration, the nano bubble cleaning liquid WnB ejected from the cleaning nozzle 14a collides with the plate surface 26fa, so that the nano liquid nB subjected to the short life treatment and the micro bubbles are contained in the cleaning liquid W. μB is generated and becomes short-lived bubble cleaning liquid WBs. The short-life bubble cleaning liquid WBs comes into contact with the cleaning target Pro.
　なお、固体による衝突面２６ａは、平面だけで構成されていてもよいが、凹凸を有する面であってもよい。また、固体による衝突面２６ａは、回転等の運動が与えられていてもよい。衝突したときの衝撃が生じやすく、マイクロ気泡μＢが生成しやすくなるからである。 The solid collision surface 26a may be a flat surface, but may be a surface having irregularities. The solid collision surface 26a may be given a motion such as rotation. This is because impact upon collision is likely to occur and micro bubbles μB are likely to be generated.
　図３（ｃ）は、衝突処理体２６が内部に縦方向の仕切りが施されたもので、例えば、両側が開口したハニカム構造体状に形成されたものである。ナノ気泡洗浄液ＷｎＢは、仕切りを構成する桟（縦壁）の部分に衝突し、ナノ気泡ｎＢは短寿命処理を受ける。また、ナノ気泡ｎＢと衝突したときの衝撃によってマイクロ気泡μＢが生成される。そしてナノ気泡洗浄液ＷｎＢは、短寿命気泡洗浄液ＷＢｓとなり、下方の被洗浄物Ｐｒｏに落下し、接触する。仕切りの高さは、短くてもよく、網状であってもよい。 FIG. 3 (c) shows the interior of the collision processing body 26 that is partitioned in the vertical direction, and is formed, for example, in the shape of a honeycomb structure having openings on both sides. The nano-bubble cleaning liquid WnB collides with the portion of the crosspiece (vertical wall) forming the partition, and the nanobubbles nB are subjected to a short life treatment. In addition, micro bubbles μB are generated by the impact when colliding with the nano bubbles nB. Then, the nano-bubble cleaning liquid WnB becomes the short-lived bubble cleaning liquid WBs, and drops and contacts the cleaning object Pro below. The height of the partition may be short or may be mesh-like.
　図３（ｄ）は、衝突処理体２６が液面２６ｓだけで構成されている場合を示す。被洗浄物Ｐｒｏを一定深さの液体（洗浄液Ｗ若しくは短寿命気泡洗浄液ＷＢｓであってよい）に浸漬しておき、上方から洗浄ノズル１４ａでナノ気泡洗浄液ＷｎＢを噴射する。液面２６ｓに衝突したナノ気泡洗浄液ＷｎＢは、短寿命処理を受ける。また、一部ナノ気泡ｎＢと衝突したときの衝撃によってマイクロ気泡μＢが生成される。また、薬液処理工程後の洗浄工程においては、被洗浄物Ｐｒｏの表面に残存している薬液が衝突処理体２６を構成する場合もある。 FIG. 3D shows a case where the collision processing body 26 is composed of only the liquid surface 26s. The cleaning target Pro is immersed in a liquid having a certain depth (which may be the cleaning liquid W or the short-lived bubble cleaning liquid WBs), and the nano bubble cleaning liquid WnB is jetted from above by the cleaning nozzle 14a. The nanobubble cleaning liquid WnB that has collided with the liquid surface 26s undergoes a short life treatment. In addition, micro bubbles μB are generated by the impact when they partially collide with the nano bubbles nB. Further, in the cleaning step after the chemical solution processing step, the chemical solution remaining on the surface of the object to be cleaned Pro may constitute the collision processing body 26.
　図４には、衝突処理体２６の端部が、短寿命気泡洗浄液ＷＢｓに浸漬している場合を示す。後述する実施例より、ナノ気泡洗浄液ＷｎＢは、壁に当たって流下する場合に、流下した液体から多数のマイクロ気泡μＢを発生させることが分かった。さらに、ナノ気泡洗浄液ＷｎＢは、衝突速度が遅い場合には、液面付近でしかマイクロ気泡μＢが発生しない。一方、ナノ気泡洗浄液ＷｎＢが、壁に当たって流下する場合には、水深深くまでマイクロ気泡μＢが生じていることが確認できた。 FIG. 4 shows a case where the end of the collision processing body 26 is immersed in the short-life bubble cleaning liquid WBs. From the examples described below, it was found that the nanobubble cleaning liquid WnB, when hitting a wall and flowing down, generated a large number of microbubbles μB from the flowing-down liquid. Further, in the nanobubble cleaning liquid WnB, when the collision speed is slow, the microbubbles μB are generated only near the liquid surface. On the other hand, when the nanobubble cleaning liquid WnB hits the wall and flows down, it was confirmed that the microbubbles μB were generated deep in the water.
　そこで、図４は、衝突処理体２６の端が液面に浸かっている構成である。ナノ気泡洗浄液ＷｎＢは、衝突処理体２６に衝突してから衝突処理体２６を流下して、被洗浄物Ｐｒｏが浸漬されている洗浄液Ｗ（短寿命気泡洗浄液ＷＢｓ）に至る。そして、浸入点から一定の深さまでマイクロ気泡μＢを発生させる。なお、図４では、衝突処理体２６を４５度の傾斜で下方を短寿命気泡洗浄液ＷＢｓに浸漬させたが、垂直（９０度）で浸漬させてもよく、傾斜角は限定されない。 Therefore, FIG. 4 shows a configuration in which the end of the collision processing body 26 is immersed in the liquid surface. The nano bubble cleaning liquid WnB collides with the collision processing body 26 and then flows down through the collision processing body 26 to reach the cleaning liquid W (short-lived bubble cleaning liquid WBs) in which the cleaning target Pro is immersed. Then, micro bubbles μB are generated from the entry point to a certain depth. Note that, in FIG. 4, the collision processing body 26 is immersed in the short-life bubble cleaning liquid WBs with a tilt of 45 degrees, but it may be immersed vertically (90 degrees), and the tilt angle is not limited.
　したがって、被洗浄物Ｐｒｏは、マイクロ気泡μＢが生じている深さに配置されていればよく、液面からの深さを厳しく管理する必要がない。結果、調整が非常に容易な微細気泡洗浄装置１を得ることができる。また、ナノ気泡洗浄液ＷｎＢが、衝突処理体２６に衝突することで短寿命気泡洗浄液ＷＢｓとなった後、落下して被洗浄物Ｐｒｏに衝突する場合よりも、被洗浄物Ｐｒｏが受けるダメージははるかに小さい。したがって、洗浄時に被洗浄物Ｐｒｏが受けるダメージをほとんど考慮する必要がない。したがって、超微細加工が施された被洗浄物Ｐｒｏであっても、安心して洗浄することができる。 Therefore, the cleaning object Pro need only be arranged at the depth where the micro bubbles μB are generated, and it is not necessary to strictly control the depth from the liquid surface. As a result, it is possible to obtain the fine bubble cleaning device 1 that is extremely easy to adjust. Further, the nano-bubble cleaning liquid WnB collides with the collision processing body 26 to become the short-lived bubble cleaning liquid WBs, and then, the damage to the cleaning target Pro is far less than that when the nano-bubble cleaning liquid WnB drops and collides with the cleaning target Pro. Small. Therefore, it is almost unnecessary to consider the damage to the cleaning target Pro during cleaning. Therefore, even the object Pro to be cleaned that has been subjected to ultrafine processing can be safely cleaned.
　このように衝突処理体２６は、被洗浄物Ｐｒｏと、洗浄ノズル１４ａとの間に配置され、洗浄ノズル１４ａから吐出されるナノ気泡洗浄液ＷｎＢが衝突した際に、物理的な力をナノ気泡洗浄液ＷｎＢに与えるものである。 As described above, the collision processing body 26 is disposed between the object to be cleaned Pro and the cleaning nozzle 14a, and when the nano bubble cleaning liquid WnB discharged from the cleaning nozzle 14a collides, the physical force is applied to the nano bubble cleaning liquid. It is given to WnB.
　図１を再度参照して、微細気泡洗浄装置１は、制御装置３０を有していてもよい。制御装置３０は、第１バブルモニタ２０と第２バブルモニタ２２からの信号Ｓ１、Ｓ２を受信し、気泡の生成量を調節するために、微細気泡発生装置１０への指示信号ＣＢ０およびポンプＰ１、Ｐ２、Ｐ３への指示信号ＣＰ１、ＣＰ２、ＣＰ３を送信する。 Referring again to FIG. 1, the fine bubble cleaning device 1 may include a control device 30. The control device 30 receives the signals S1 and S2 from the first bubble monitor 20 and the second bubble monitor 22, and in order to adjust the production amount of bubbles, an instruction signal CB0 to the fine bubble generation device 10 and a pump P1, The instruction signals CP1, CP2, CP3 to P2, P3 are transmitted.
　図５に実験の構成を示す。洗浄液Ｗとしてイオン交換水を用意した。洗浄液Ｗは、貯留槽１６に注水され、貯留槽１６に設けられた循環配管ｒ１によって微細気泡発生装置１０に供給される。微細気泡発生装置１０は、Ｌｉｇａｒｉｃ社製Ｂｕｖｉｔａｓ　ＨＹＫ－３２Ｄを用いた。微細気泡発生装置１０には、気体（酸素）供給源Ｇａｓを接続し、酸素濃度１８ｐｐｍのナノ気泡洗浄液ＷｎＢを生成させた。また、微細気泡発生装置１０は、１分間に７００ｍＬのガスを流してナノ気泡洗浄液ＷｎＢを生成することができる。 Fig. 5 shows the structure of the experiment. Ion-exchanged water was prepared as the cleaning liquid W. The cleaning liquid W is poured into the storage tank 16 and is supplied to the fine bubble generation device 10 by the circulation pipe r1 provided in the storage tank 16. As the fine bubble generator 10, Buvitas HYK-32D manufactured by Ligaric was used. A gas (oxygen) supply source Gas was connected to the fine bubble generator 10 to generate a nano bubble cleaning liquid WnB having an oxygen concentration of 18 ppm. Further, the fine bubble generator 10 can generate a nano bubble cleaning liquid WnB by flowing 700 mL of gas for 1 minute.
　貯留槽１６に蓄えられたナノ気泡洗浄液ＷｎＢは、加圧装置９４に送られ、加圧されて洗浄ノズル１４ａに送出された。加圧装置９４は、ステンレス加圧容器（２．５Ｌ　ＴＡ１００Ｎ）を用いた。加圧装置９４によって吐出圧を調節した。 The nano-bubble cleaning liquid WnB stored in the storage tank 16 was sent to the pressurizing device 94, pressurized, and sent to the cleaning nozzle 14a. As the pressure device 94, a stainless pressure container (2.5 L TA100N) was used. The pressurizing device 94 adjusted the discharge pressure.
　洗浄ノズル１４ａは、噴射角が６５度となるノズル（スプレーイングシステムズ社製ＴＰＵ６５００３３）を用いた。また、吐出対象は直径約７０ｍｍのメスシリンダー９６を用いた。 As the cleaning nozzle 14a, a nozzle (TPU650033 manufactured by Spraying Systems Co., Ltd.) having an injection angle of 65 degrees was used. A graduated cylinder 96 having a diameter of about 70 mm was used as a discharge target.
　気泡濃度計測装置９８は、マルバーン社製のＮａｎｏｓｉｇｈｔ　ＬＭ－１０を用いた。これは赤色レーザー（波長：６３８ｎｍ）を用いており、気泡径３０～１０００ｎｍの気泡を検出することができた。 As the bubble concentration measuring device 98, Nanosight LM-10 manufactured by Malvern was used. This uses a red laser (wavelength: 638 nm) and was able to detect bubbles having a bubble diameter of 30 to 1000 nm.
　実験の手順は以下のようにした。メスシリンダー９６中に微細気泡発生装置１０で生成したナノ気泡洗浄液ＷｎＢを１Ｌ入れた。次に洗浄ノズル１４ａからナノ気泡洗浄液ＷｎＢを所定の圧力で吐出させた。ナノ気泡洗浄液ＷｎＢは、メスシリンダー９６の内壁および液面に衝突する。メスシリンダー９６の液面付近から衝突後の洗浄液Ｗを採取し、気泡濃度計測装置９８で気泡の分布を計測した。 The procedure of the experiment was as follows. Into the graduated cylinder 96, 1 L of the nano bubble cleaning liquid WnB generated by the fine bubble generator 10 was placed. Next, the nano bubble cleaning liquid WnB was discharged from the cleaning nozzle 14a at a predetermined pressure. The nano bubble cleaning liquid WnB collides with the inner wall and the liquid surface of the graduated cylinder 96. The cleaning liquid W after the collision was collected from the vicinity of the liquid surface of the measuring cylinder 96, and the distribution of bubbles was measured by the bubble concentration measuring device 98.
　図６に測定結果を示す。横軸は気泡径（ｎｍ）を表し、縦軸は濃度（１０６個／ｍＬ）を表す。Ａのラインは、微細気泡発生装置１０で生成したメスシリンダー９６に吐出する前のナノ気泡洗浄液ＷｎＢの分布を示す。８０ｎｍから１５０ｎｍに分布の主領域がある。 The measurement results are shown in FIG. The horizontal axis represents the bubble diameter (nm), and the vertical axis represents the concentration (10 6 cells / mL). The line A indicates the distribution of the nano bubble cleaning liquid WnB generated in the fine bubble generator 10 before being discharged to the graduated cylinder 96. There is a main region of distribution from 80 nm to 150 nm.
　Ｂのラインは、０．１ＭＰａの圧力で吐出させた時の衝突後の洗浄液Ｗの気泡分布である。分布はＡのラインと比較してブロードになり、３００ｎｍの付近の分布が衝突前の状態と比較して多くなっているのがわかる。このように、ナノ気泡ｎＢは気泡径が大きくなることで、安定性が破壊され、ナノ気泡ｎＢの寿命は短くなる。 The line B is the bubble distribution of the cleaning liquid W after collision when discharged at a pressure of 0.1 MPa. It can be seen that the distribution becomes broader than that of the line A, and the distribution around 300 nm is larger than that before the collision. As described above, the nanobubble nB has a large bubble diameter, so that the stability is destroyed and the life of the nanobubble nB is shortened.
　図７（ａ）は、純水をメスシリンダー９６に入れた後、純水を洗浄ノズル１４ａから吐出させた場合の写真を示す。また図７（ｂ）は、ナノ気泡洗浄液ＷｎＢをメスシリンダー９６に入れた後、ナノ気泡洗浄液ＷｎＢを洗浄ノズル１４ａから吐出させた場合の写真を示す。すなわち、図７（ｂ）は図６のＢラインの状態である。 FIG. 7A shows a photograph when pure water is put into the graduated cylinder 96 and then the pure water is discharged from the cleaning nozzle 14a. Further, FIG. 7B shows a photograph when the nano bubble cleaning liquid WnB is put into the measuring cylinder 96 and then the nano bubble cleaning liquid WnB is ejected from the cleaning nozzle 14a. That is, FIG. 7B shows the state of line B in FIG.
　図７（ａ）の領域Ｃと図７（ｂ）の領域Ｄは共にマイクロ気泡μＢが発生している領域である。洗浄ノズル１４ａから吐出させ、メスシリンダー９６の内壁と液面に衝突した際の衝撃によってマイクロ気泡μＢが発生する。マイクロ気泡μＢが発生している部分は写真上では白濁して見える。 The area C in FIG. 7A and the area D in FIG. 7B are both areas where micro bubbles μB are generated. The micro bubbles μB are generated by the impact when the liquid is discharged from the cleaning nozzle 14a and collides with the inner wall of the measuring cylinder 96 and the liquid surface. The portion in which micro bubbles μB are generated appears cloudy on the photograph.
　領域Ｃと領域Ｄでは、領域Ｄの方が大きく観察される。つまり、ナノ気泡洗浄液ＷｎＢの場合の方（図７（ｂ））が、純水（図７（ａ））と比較して、マイクロ気泡μＢがより多く発生している。これは、衝突した際の衝撃によるマイクロ気泡μＢだけでなく、ナノ気泡ｎＢがマイクロ気泡μＢに成長したからと考えられる。 In area C and area D, area D is observed larger. That is, in the case of the nano bubble cleaning liquid WnB (FIG. 7 (b)), more micro bubbles μB are generated as compared with the pure water (FIG. 7 (a)). It is considered that this is because not only the micro bubbles μB due to the impact at the time of collision but also the nano bubbles nB grew into the micro bubbles μB.
　また、図７（ａ）の純水の場合では、Ｅの領域等に、この倍率でさえ泡と視認できる程度の大きさであるミリ気泡が多く発生している。ミリ気泡の発生量は明らかに図７（ａ）の純水を用いた場合の方が図７（ｂ）のナノ気泡洗浄液ＷｎＢの場合より多い。これは、以下の理由によるものと考えられる。 Also, in the case of the pure water of FIG. 7 (a), many milli-bubbles are generated in the area E, etc., which are of a size that can be visually recognized as bubbles even at this magnification. The amount of millimeter bubbles generated is obviously higher in the case of using the pure water of FIG. 7A than in the case of the nanobubble cleaning liquid WnB of FIG. 7B. This is considered to be due to the following reasons.
　ナノ気泡洗浄液ＷｎＢは初期の溶存ガス量を１８ｐｐｍと純水より高く、飽和濃度より高めている。したがって、ナノ気泡洗浄液ＷｎＢは、吐出（加圧から減圧）された際に溶存ガスがバブル化して液滴を細かくする上に、吐出した際に圧力バランスを壊した液滴内のナノ気泡ｎＢの一部が大きくなって壊れる際に液滴を小さくしていると考えられる。 The nano-bubble cleaning liquid WnB has an initial dissolved gas amount of 18 ppm, which is higher than pure water and higher than the saturation concentration. Therefore, the nano-bubble cleaning liquid WnB becomes a bubble of the dissolved gas when ejected (pressurized to depressurized) to make the droplet finer, and the nano-bubble nB in the droplet whose pressure balance is broken when ejected. It is considered that the droplet is made smaller when a part of it becomes large and breaks.
　一方、純水は溶存ガスが少ないためナノ気泡洗浄液ＷｎＢよりも吐出後の液滴が大きく、液面に衝突し、液面上の空気を巻き込みミリ気泡を形成すると考えられる。 On the other hand, it is considered that pure water has a small amount of dissolved gas and thus has larger droplets after being ejected than the nano-bubble cleaning liquid WnB, colliding with the liquid surface and entraining air on the liquid surface to form millibubbles.
　次に噴射角が６５度となるノズル（スプレーイングシステムズ社製ＴＰＵ６５００１７）を用い、スプレー高さを変えた実験を行った。吐出対象は同じく直径約７０ｍｍのメスシリンダー９６を用いた。結果の写真を図８に示す。図８（ａ）は、液面からのスプレー高さが４０ｍｍであり、図８（ｂ）は液面からのスプレー高さが１００ｍｍであり、図８（ｃ）は液面からのスプレー高さが１２０ｍｍであり、図８（ｄ）は液面からのスプレー高さが１８０ｍｍの場合である。スプレー圧力は０．３ＭＰａとした。また、酸素濃度は１８ｐｐｍのナノ気泡洗浄液ＷｎＢを使用した。 Next, an experiment was conducted in which the spray height was changed using a nozzle (TPU650017 manufactured by Spraying Systems Co., Ltd.) with an injection angle of 65 degrees. Similarly, a graduated cylinder 96 having a diameter of about 70 mm was used as a discharge target. The result photograph is shown in FIG. 8A shows a spray height from the liquid surface of 40 mm, FIG. 8B shows a spray height from the liquid surface of 100 mm, and FIG. 8C shows a spray height from the liquid surface. Is 120 mm, and FIG. 8D shows a case where the spray height from the liquid surface is 180 mm. The spray pressure was 0.3 MPa. Further, the nanobubble cleaning liquid WnB having an oxygen concentration of 18 ppm was used.
　図８（ａ）を参照して、スプレー打力が強いと考えられるスプレー高さ４０ｍｍの場合は、スプレーが液面に当たった衝突部分Ｆで、スプレー打力およびそこから発生した巻き込み気体Ｇによって、プランジングジェット現象が発生し、マイクロ気泡μＢとミリ気泡が多く発生した。 Referring to FIG. 8A, when the spray height is 40 mm, which is considered to have a strong spray hitting force, the spray hitting force and entrained gas G generated from the hitting part F where the spray hits the liquid surface. The plunging jet phenomenon occurred, and many micro bubbles μB and milli bubbles were generated.
　図８（ｂ）から図８（ｄ）を参照して、スプレー高さが高くなるほどスプレー打力は小さくなると考えられる。したがって、衝突部分Ｆでのプランジングジェット現象は発生していなかった。衝突部分Ｆ付近では液面に近い部分にマイクロ気泡μＢが発生していた。 Referring to FIGS. 8 (b) to 8 (d), it is considered that the higher the spray height, the smaller the spray hitting force. Therefore, the plunging jet phenomenon at the collision portion F did not occur. In the vicinity of the collision portion F, micro bubbles μB were generated near the liquid surface.
　一方、図８（ｂ）および図８（ｃ）を参照して、壁面に当たり、壁面を流下して液面に到達した部分では、マイクロ気泡μＢが液面から深い位置まで発生していた（Ｈ部分）。このことより、ナノ気泡洗浄液ＷｎＢを一度壁面に衝突させ、衝突した面を流下させて液面に到達させることで、深い位置までマイクロ気泡μＢを発生させることができることがわかった。 On the other hand, referring to FIGS. 8 (b) and 8 (c), micro bubbles μB were generated from the liquid surface to a deep position at the portion which hits the wall surface and flows down the wall surface to reach the liquid surface (H part). From this, it was found that the microbubbles μB can be generated at a deep position by causing the nanobubble cleaning liquid WnB to once collide with the wall surface and allowing the colliding surface to flow down and reach the liquid surface.
　また、スプレーからの距離が、４０ｍｍ～１００ｍｍ近傍までは、被洗浄物Ｐｒｏに直接スプレーすると、打力が強いため、デバイスの受けるダメージは、デバイスのパターンを破壊するほどに発展する可能性が高い。至近距離からのスプレーはプランジングジェット現象が生じるほど強力だからである。しかし、スプレーからの距離が、１２０ｍｍ以上と、遠い場合には、スプレー打力は、パターンに対して適切な強さとなり、マイクロ気泡μＢの発生による洗浄の効果が上がると考えられる。 Further, when the distance from the spray is in the vicinity of 40 mm to 100 mm, if the object to be cleaned Pro is directly sprayed, the hitting force is strong, and therefore the damage to the device is likely to develop to the extent that the device pattern is destroyed. . This is because the spray from a close range is so powerful that a plunging jet phenomenon occurs. However, when the distance from the spray is as long as 120 mm or more, the spray striking force has an appropriate strength for the pattern, and it is considered that the cleaning effect is enhanced by the generation of the micro bubbles μB.
　図９は、溶存酸素量３２ｐｐｍ（上記の実験より溶存酸素量を多くした）と溶存酸素量７ｐｐｍの精製水（通常の水の酸素濃度）を用いて、スプレー打力の小さい状態（スプレー高さ１８０ｍｍ）で液面に衝突した後にどのような気泡が発生するかを高速度カメラで分析した結果を示す。溶存酸素量３２ｐｐｍは「酸素ＵＦＢ水」と記載し、精製水は「精製水」と示した。 FIG. 9 shows a state where the spray hitting force is small (spray height) by using dissolved water amount of 32 ppm (the dissolved oxygen amount was increased from the above experiment) and purified water of dissolved oxygen amount of 7 ppm (normal water oxygen concentration). The result of analyzing with a high-speed camera what kind of bubbles are generated after colliding with the liquid surface at 180 mm) is shown. The dissolved oxygen amount of 32 ppm was described as "oxygen UFB water", and the purified water was shown as "purified water".
　横軸は気泡径（μｍ）であり、縦軸は個数（個／面内）を表す。ここで、面内とは、高速度カメラの１画面内を示す。グラフより酸素含有量が多い場合の方が、酸素含有量が少ない場合よりもマイクロ気泡μＢの発生量が非常に多いことがわかった（およそ２７倍＿単位体積当り）。これは、溶存ガスやナノ気泡ｎＢを核としてキャビテーション気泡が発生したためと考えられる。この結果より、溶存ガス濃度の高いナノ気泡洗浄液ＷｎＢは液面に強く衝突させなくても、マイクロ気泡μＢを多く発生し、洗浄効果の期待できる短寿命気泡洗浄液ＷＢｓが生成されていると考えられる。 -The horizontal axis represents the bubble diameter (μm), and the vertical axis represents the number (number / in-plane). Here, “in-plane” refers to the inside of one screen of the high-speed camera. It was found from the graph that when the oxygen content was high, the amount of microbubbles μB generated was much higher than when the oxygen content was low (approximately 27 times per unit volume). It is considered that this is because cavitation bubbles were generated with the dissolved gas and the nano bubbles nB as nuclei. From this result, it is considered that the nanobubble cleaning liquid WnB having a high dissolved gas concentration generates a large amount of microbubbles μB without strongly colliding with the liquid surface, and the short-lived bubble cleaning liquid WBs expected to have a cleaning effect is generated. .
　次に短寿命気泡洗浄液ＷＢｓにおいて、マイクロ気泡μＢの発生から破壊までの時間差について調べた。図１０は、斜面にナノ気泡洗浄液ＷｎＢを当てた時の温度変化を、シリコン基板の裏面に熱電対を張り付けて温度測定したものである。図１０（ａ）は、実験装置の側面概念図である。傾斜面から１２０ｍｍ離れた点に洗浄ノズル１４ａ（噴射角６５°）を配置し、０．３ＭＰａの圧力で精製水によるナノ気泡洗浄液ＷｎＢを噴射した。そして、傾斜面上の３点（噴射中心とその２５ｍｍ上部の点、および２５ｍｍ下部の点）の温度をシリコン基板の裏面に熱電対を張り付けて調べた。なお、噴出中心は「〇中心」とし、噴出中心から２５ｍｍ上部の点を「■上部」とし、噴出中心から２５ｍｍ下部の点を「×下部」と表した。 Next, in the short-lived bubble cleaning liquid WBs, the time difference from the generation of microbubbles μB to the destruction was examined. FIG. 10 shows the temperature change when the nano-bubble cleaning liquid WnB was applied to the slope, and the temperature was measured by attaching a thermocouple to the back surface of the silicon substrate. FIG. 10A is a side view conceptual diagram of the experimental apparatus. The cleaning nozzle 14a (jet angle 65 °) was arranged at a point 120 mm away from the inclined surface, and the nanobubble cleaning liquid WnB with purified water was sprayed at a pressure of 0.3 MPa. Then, the temperatures at three points on the inclined surface (the injection center, the point 25 mm above and the point 25 mm below) were examined by attaching thermocouples to the back surface of the silicon substrate. In addition, the ejection center is represented by "o center", the point 25 mm above the ejection center is represented by "■ upper part", and the point 25 mm below the ejection center is represented by "x lower part".
　図１０（ｂ）は、精製水を用いたナノ気泡洗浄液ＷｎＢの場合の各点における温度を表したものである。横軸は噴出後に計測を始めてからの経過時間（秒：「ｓｅｃ」と記した。）であり、縦軸は温度（℃）である。中心部（〇印）と下部（×印）はほぼ同じ温度の推移をした。上部（■印）は、噴出し計測を開始するまでの数秒後から温度は１８０秒以降も噴出の中心部も上部も下部も一定で安定していた。なお、図１０（ｂ）では、上部を「■　Ｗａｔｅｒ　ＣＨ１」と示し、中心部を「〇　Ｗａｔｅｒ　ＣＨ２」と示し、下部を「×　Ｗａｔｅｒ　ＣＨ３」と示した。 FIG. 10 (b) shows the temperature at each point in the case of the nano bubble cleaning liquid WnB using purified water. The horizontal axis is the elapsed time (seconds: described as “sec”) after the start of measurement after ejection, and the vertical axis is the temperature (° C.). The temperature changes in the central part (marked with ◯) and the lower part (marked with x) are almost the same. In the upper part (marked by ■), the temperature was constant for a few seconds after the start of the ejection measurement and after 180 seconds, the central portion, the upper portion and the lower portion of the ejection were constant and stable. In FIG. 10 (b), the upper part is shown as “■ Water CH1”, the central part is shown as “〇Water CH2”, and the lower part is shown as “× Water CH3”.
　図１０（ｃ）は、酸素を３２ｐｐｍ含有するナノ気泡洗浄液ＷｎＢの場合の結果を示したものである。計測開始直後は、上部（■印）は最も低く、中心部（〇印）はそれより約０．７℃ほど高かった。しかし、下部（×印）は中心部（〇印）より約１℃ほど明確に高く、しかもこれらの関係は安定していた。このことは、ナノ気泡洗浄液ＷｎＢが斜面に衝突することでマイクロ気泡μＢを有する短寿命気泡洗浄液ＷＢｓとなり、その後流下する時間の経過後にマイクロ気泡μＢが破壊した点で熱が発生すると考えられた。このことより、マイクロ気泡μＢは発生してから一定時間後に破壊することが確認できた。なお、図１０（ｃ）では、上部を「■　Ｏ２ＮＢ　上部」と示し、中心部を「〇　Ｏ２ＮＢ　中心」と示し、下部を「×　Ｏ２ＮＢ　下部」と示した。 FIG. 10C shows the result in the case of the nano bubble cleaning liquid WnB containing 32 ppm of oxygen. Immediately after the start of the measurement, the upper part (marked with ■) was the lowest, and the central part (marked with ◯) was higher by about 0.7 ° C. However, the lower part (marked with x) was clearly higher than the center part (marked with ◯) by about 1 ° C., and these relationships were stable. It is considered that this is because the nano-bubble cleaning liquid WnB collides with the slope to become the short-lived bubble cleaning liquid WBs having the micro bubbles μB, and heat is generated at the point where the micro bubbles μB are destroyed after a lapse of the subsequent flow time. From this, it was confirmed that the microbubbles μB were destroyed after a certain time from the generation. In FIG. 10 (c), the upper shown as "■ O 2 NB top", a central portion indicated as "〇 O 2 NB center", showed lower as "× O 2 NB bottom".
　図１１に、衝突処理体２６が液面２６ｓだけで構成されている場合（図３（ｄ）参照）の実施例を示す。図１１（ｂ）を参照する。被洗浄物Ｐｒｏとして「ＧＫＥ洗浄インジケータ（ｇｋｅ社製　代理店：株式会社名優）」を用いた。これはＬ１～Ｌ４までの疑似的な汚れが付いたシートで構成される。Ｌ１からＬ４までの各シートは、種類の異なる疑似的な汚れが基材上に形成されたものである。さまざまな洗浄力を図るインジケータであるため、いずれのシートも水だけでは全く汚れを落とすことはできない。 FIG. 11 shows an embodiment in which the collision processing body 26 is composed of only the liquid surface 26s (see FIG. 3D). Reference is made to FIG. As the object to be cleaned Pro, "GKE cleaning indicator (Distributor by gke: Meiyu Co. Ltd.)" was used. This is composed of sheets with pseudo stains L1 to L4. Each of the sheets L1 to L4 has different types of pseudo stains formed on the base material. Since it is an indicator for various detergency, neither of the sheets can be completely cleaned with water.
　この疑似的な汚れは、温度で取れる汚れであったり、洗浄水のｐＨで取れる汚れなどが用意されている。ここでは半導体の洗浄状態に最も近い状況で洗浄することができたＬ２（ｐＨで取れる汚れ）を用いた。 This pseudo stain is a stain that can be taken with temperature, or a stain that can be taken with the pH of the wash water. Here, L2 (dirt that can be taken at pH) that can be washed in a state closest to the semiconductor washing state was used.
　実験装置は図１１（ａ）に示すように、容器４０の底に、被洗浄物Ｐｒｏ（ＧＫＥ洗浄インジケータ）を固定し、容器４０中に１０ｍＬのアルカリ洗浄液４２を満たした。容器４０の液面から被洗浄物Ｐｒｏまでの深さは約１ｍｍであった。アルカリ洗浄液４２は通常用いる濃度ではｐＨが１３以上であるのに対し１００倍に希釈して溶解力を弱めたものでｐＨは約１０～１２であった。スプレーノズル１４ａ（スプレーイングシステムズ社製ＴＰＵ６５００１７）は被洗浄物Ｐｒｏから１００ｍｍ離れた位置にセットした。 As shown in FIG. 11 (a), the experimental apparatus fixed the object to be cleaned Pro (GKE cleaning indicator) to the bottom of the container 40 and filled the container 40 with 10 mL of the alkaline cleaning liquid 42. The depth from the liquid surface of the container 40 to the cleaning object Pro was about 1 mm. The pH of the alkaline cleaning liquid 42 was 13 or more at the concentration usually used, whereas the alkaline cleaning liquid 42 was diluted 100 times to weaken the dissolving power, and the pH was about 10-12. The spray nozzle 14a (TPU650017 manufactured by Spraying Systems Co., Ltd.) was set at a position 100 mm away from the cleaning target Pro.
　図１２に図８（ｂ）の拡大図を再掲する。図１２（ａ）は、図８（ｂ）の拡大図であり、図１２（ｂ）はさらにその一部を拡大したものである。図８（ｂ）は液面からのスプレー高さが１００ｍｍの場合である。スプレーされる液面から１ｍｍ下方というのは、図１２（ｂ）の矢印の部分である。 ▽ Reproduce the enlarged view of Fig. 8 (b) in Fig. 12. FIG. 12A is an enlarged view of FIG. 8B, and FIG. 12B is a partially enlarged view thereof. FIG. 8B shows the case where the spray height from the liquid surface is 100 mm. The point 1 mm below the sprayed liquid surface is the portion indicated by the arrow in FIG.
　この部分（衝突部分Ｆ付近）ではマイクロ気泡μＢが発生しており、直接のスプレー打力は当たらない領域であった。つまり、図１１（ａ）で液面から１ｍｍ下方では、スプレーの打力が直接当たらずに、界面よりキャビテーションで発生するマイクロバブルの発生領域に当たり、スプレーされたナノ気泡洗浄液ＷｎＢが、厚さ１ｍｍの水を衝突処理体２６として短寿命処理を受け、短寿命洗浄液ＷＢｓとなっている領域であるといえる。 ▽ Micro bubble μB was generated in this part (near collision part F), and it was a region where the direct spray hitting force did not hit. That is, in FIG. 11A, below 1 mm from the liquid surface, the spraying force of the spray is not directly applied, and the sprayed nano-bubble cleaning liquid WnB has a thickness of 1 mm when it hits the generation area of micro bubbles generated by cavitation from the interface. It can be said that this is a region in which the short-life cleaning liquid WBs is obtained by subjecting the water of the above-mentioned water to the collision processing body 26 to undergo the short-life processing.
　再び図１１（ａ）を参照する。ノズル１４ａから酸素を使ったナノ気泡洗浄液ＷｎＢと精製水をスプレー圧力を０．５ＭＰａで液面に当てた。アルカリ洗浄液４２の液面は、スプレーによって徐々に高くなり、スプレー打力の被洗浄物Ｐｒｏ（ＧＫＥ洗浄インジケータ）への影響もより小さくなる。ナノ気泡洗浄液ＷｎＢも精製水に酸素のナノ気泡を混入させたものなので、容器４０中のｐＨは時間の経過とともに薄くなる。スプレー時間は２分とした。 Refer to FIG. 11 (a) again. The nano bubble cleaning liquid WnB using oxygen and purified water were applied to the liquid surface from the nozzle 14a at a spray pressure of 0.5 MPa. The liquid level of the alkaline cleaning liquid 42 is gradually increased by spraying, and the influence of the spray hitting force on the object to be cleaned Pro (GKE cleaning indicator) is further reduced. Since the nano-bubble cleaning liquid WnB is also a mixture of purified water with oxygen nano-bubbles, the pH in the container 40 becomes thin with the passage of time. The spray time was 2 minutes.
　図１３に結果を示す。図１３（ａ）、図１３（ｂ）はナノ気泡洗浄液ＷｎＢの場合であり、図１３（ｃ）、図１３（ｄ）は精製水の場合である。また、図１３（ａ）および（ｄ）は、スプレー停止直後の容器４０中のシートの写真である。図１３（ｂ）および（ｄ）は、洗浄後のシートの汚れの部分の拡大図である。 Fig. 13 shows the result. 13A and 13B show the case of the nanobubble cleaning liquid WnB, and FIGS. 13C and 13D show the case of purified water. 13A and 13D are photographs of the sheet in the container 40 immediately after the spraying is stopped. 13B and 13D are enlarged views of the soiled portion of the sheet after cleaning.
　図１３（ａ）を観察すると、スプレー停止直後にシートから溶出した汚れ成分４４が確認できた。一方、図１３（ｃ）では、そのような汚れ成分の剥離は確認できなかった。 From the observation of FIG. 13 (a), the stain component 44 eluted from the sheet was confirmed immediately after stopping the spraying. On the other hand, in FIG. 13C, such peeling of the stain component could not be confirmed.
　図１３（ｂ）および（ｄ）は洗浄後の汚れ成分である。この画像を画像処理ソフト（ｃｏｌｏｒ　ｓｐａｔｉｏｐｌｏｔｔｅｒ）で画像処理し、緑色の強さと度数分析を行った。 13 (b) and 13 (d) are the stain components after cleaning. This image was subjected to image processing with image processing software (color spatial plotter), and the intensity of green and frequency analysis were performed.
　図１４にその結果を示す。図１４（ａ）はナノ気泡洗浄液ＷｎＢを用いた場合であり、図１４（ｂ）は精製水を用いた場合である。それぞれのグラフで、横軸は緑色の強さであり、縦軸ｊは度数を示す。ナノ気泡洗浄液ＷｎＢを用いた場合、緑色の強さの平均値は０．５９０であったのに対して、精製水では０．６２１であった。すなわち、ナノ気泡洗浄液ＷｎＢを用いることで、緑色の強度を低下させることができた。これは緑色の疑似汚れを除去した結果であり、ナノ気泡洗浄液ＷｎＢには洗浄力があることを示すことを確認できた。 Fig. 14 shows the result. FIG. 14A shows the case where the nanobubble cleaning liquid WnB is used, and FIG. 14B shows the case where purified water is used. In each graph, the horizontal axis represents green intensity and the vertical axis j represents frequency. When the nano-bubble cleaning liquid WnB was used, the average intensity of green color was 0.590, whereas that of purified water was 0.621. That is, it was possible to reduce the intensity of the green color by using the nano bubble cleaning liquid WnB. This is a result of removing the green pseudo stain, and it was confirmed that the nanobubble cleaning liquid WnB has a cleaning power.
　以上のように、ナノ気泡洗浄液ＷｎＢを衝突処理体２６に衝突させることで、ナノ気泡ｎＢを短寿命処理することができ、さらに、マイクロ気泡μＢの発生量も増大させることができる。また、ナノ気泡洗浄液ＷｎＢを衝突処理体２６に衝突させても、ミリ気泡は多く発生せず、洗浄力が阻害されることはない。 As described above, by colliding the nano-bubble cleaning liquid WnB with the collision treatment body 26, it is possible to treat the nano-bubbles nB for a short life and further increase the generation amount of the micro-bubbles μB. Further, even if the nano-bubble cleaning liquid WnB collides with the collision processing body 26, many millimeter bubbles are not generated and the cleaning power is not impaired.
　本発明に係る微細気泡洗浄装置は、半導体や電子デバイスの洗浄工程に好適に利用することができる。また、配管等の内壁の洗浄にも好適に利用することができる。 The micro-bubble cleaning device according to the present invention can be suitably used in the cleaning process of semiconductors and electronic devices. Further, it can be suitably used for cleaning the inner wall of piping and the like.
　１　　微細気泡洗浄装置
　１０　　微細気泡発生装置
　１４　　洗浄槽
　１４ａ　　洗浄ノズル
　１６　　貯留槽
　２０　　第１バブルモニタ
　２２　　第２バブルモニタ
　２６　　衝突処理体
　２６ａ　　衝突面
　２６ｏ　　吐出口
　２６ｔ　　筒体
　２６ｔａ　　内壁
　２６ｓ　　液面
　２６ｆ　　板状物
　２６ｆａ　　板面
　３０　　制御装置
　４０　　容器
　４２　　アルカリ洗浄液
　４４　　汚れ成分
　７０　　薬液装置
　７１　　ディスク
　７２　　薬液ノズル
　７３　　薬液タンク
　７４　　ポンプ
　７５　　フィルタ
　９０　　洗浄液タンク
　９２　　酸素ボンベ
　９４　　加圧装置
　９６　　メスシリンダー
　９８　　気泡濃度計測装置
　Ｗ　　洗浄液
　ｎＢ　　ナノ気泡
　μＢ　　マイクロ気泡
　ＷｎＢ　　ナノ気泡洗浄液
　Ｇａｓ　　気体供給源
　ＷＢｓ　　短寿命気泡洗浄液
　Ｐｒｏ　　被洗浄物
　ｒ１　　循環配管
　ｒ２　　配管
　ｒｘ　　ドレイン管
　ｒ３　　帰還用配管
　Ｐ１　　ポンプ
　Ｐ２　　ポンプ
　Ｐ３　　ポンプ

  1 Micro Bubble Cleaner 10 Micro Bubble Generator 14 Cleaning Tank 14a Cleaning Nozzle 16 Storage Tank 20 First Bubble Monitor 22 Second Bubble Monitor 26 Collision Processing Body 26a Collision Surface 26o Discharge Port 26t Cylindrical Body 26ta Inner Wall 26s Liquid Surface 26f Plate-like Object 26fa Plate surface 30 Control device 40 Container 42 Alkaline cleaning liquid 44 Dirt component 70 Chemical liquid device 71 Disk 72 Chemical liquid nozzle 73 Chemical liquid tank 74 Pump 75 Filter 90 Cleaning liquid tank 92 Oxygen cylinder 94 Pressurizing device 96 Messy cylinder 98 Bubble concentration measuring device W Cleaning liquid nB nano bubbles μB micro bubbles WnB nano bubbles cleaning liquid Gas gas supply source WBs short life bubble cleaning liquid Pro to be cleaned r1 circulation pipe r2 pipe rx drain pipe r3 return pipe P1 pump P2 Pump P3 Pump

Claims (4)

  1. 　洗浄液中に少なくともナノオーダーの微細気泡を発生させ、ナノ気泡洗浄液を生成する微細気泡発生装置と、
    　前記ナノ気泡洗浄液を被洗浄物に向かって吐出する洗浄ノズルと、
    　前記洗浄ノズルと前記被洗浄物の間に設けられた衝突処理体を有することを特徴とする微細気泡洗浄装置。     A micro-bubble generator that generates at least nano-order micro bubbles in the cleaning liquid to generate nano-bubble cleaning liquid,
    A cleaning nozzle for ejecting the nano-bubble cleaning liquid toward the object to be cleaned,
    A fine bubble cleaning apparatus comprising a collision processing body provided between the cleaning nozzle and the object to be cleaned.
  2. 　前記被洗浄物は、前記洗浄液中に配置され、
    　前記衝突処理体は、前記被洗浄物の上方で前記洗浄液中に一部が浸漬していることを特徴とする請求項１に記載された微細気泡洗浄装置。     The object to be cleaned is placed in the cleaning liquid,
    The fine bubble cleaning apparatus according to claim 1, wherein a part of the collision processing body is immersed in the cleaning liquid above the object to be cleaned.
  3. 　洗浄液中に少なくともナノオーダーの微細気泡を発生させ、ナノ気泡洗浄液を生成する工程と、
    　前記ナノ気泡洗浄液を衝突処理体に衝突させ短寿命気泡洗浄液を得る工程と、
    　前記短寿命気泡洗浄液を被洗浄物に接触させる工程を有する微細気泡洗浄方法。     A step of generating at least nano-order fine bubbles in the cleaning liquid to generate a nano-bubble cleaning liquid,
    A step of colliding the nano-bubble cleaning liquid with a collision treatment body to obtain a short-lived bubble cleaning liquid;
    A method for cleaning fine bubbles, comprising a step of bringing the short-lived bubble cleaning liquid into contact with an object to be cleaned.
  4. 　前記被洗浄物を前記洗浄液中に配置する工程と、
    　前記短寿命気泡洗浄液を前記被洗浄物の上方で前記洗浄液中に浸漬した前記衝突処理体に沿わせて流下させる工程を含むことを特徴とする請求項３に記載された微細気泡洗浄方法。

          Disposing the object to be cleaned in the cleaning liquid,
    The fine bubble cleaning method according to claim 3, further comprising a step of causing the short-life bubble cleaning liquid to flow down along the collision treatment body immersed in the cleaning liquid above the object to be cleaned.

PCT/JP2019/040253 2018-10-12 2019-10-11 Fine-bubble cleaning device and fine-bubble cleaning method WO2020075844A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008087903A1 (en) * 2007-01-15 2008-07-24 Shibaura Mechatronics Corporation Apparatus and method for processing substrate
WO2011101936A1 (en) * 2010-02-18 2011-08-25 シャープ株式会社 Etching method and etching device
JP2016092340A (en) * 2014-11-10 2016-05-23 旭有機材工業株式会社 Cleaning method and device for substrate

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008087903A1 (en) * 2007-01-15 2008-07-24 Shibaura Mechatronics Corporation Apparatus and method for processing substrate
WO2011101936A1 (en) * 2010-02-18 2011-08-25 シャープ株式会社 Etching method and etching device
JP2016092340A (en) * 2014-11-10 2016-05-23 旭有機材工業株式会社 Cleaning method and device for substrate

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