JP2017191855A - Washing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing device capable of obtaining a cleaning solution having high cleanliness.SOLUTION: A washing device 10 includes: a dissolving tank 20 for dissolving gas in liquid; a transfer pump 30 for feeding the liquid together with the gas into the dissolving tank 20; and an injection nozzle 40 for injecting the liquid stored in the dissolving tank 20 to an object W. The transfer pump 30 is a positive displacement pump. Portions in contact with the liquid of the dissolving tank 20, the transfer pump 30, and the injection nozzle 40 are formed of fluorine resin. The washing device 10 includes a warming device 27 capable of warming the liquid.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cleaning apparatus used in, for example, a semiconductor cleaning process.

  In the semiconductor manufacturing process, cleaning is performed to remove particles, organic substances, etc. adhering to the silicon wafer or thin film. As a typical semiconductor cleaning technique, there is an RCA cleaning method. The RCA cleaning method is a Si substrate wet cleaning method based on cleaning with ammonia / hydrogen peroxide solution (SC1) and cleaning with hydrochloric acid / hydrogen peroxide solution (SC2).

  In addition, a semiconductor cleaning method using the ability to decompose organic substances by OH radicals contained in ozone water is also known. For example, Patent Document 1 discloses a semiconductor wafer cleaning system including a cleaning device that cleans a semiconductor wafer with ozone water and an ozone water manufacturing device that supplies ozone water to the cleaning device.

JP 2010-177535 A

  It is said that it is difficult to keep the concentration of ozone dissolved in water high for a long period of time. The reason is that ozone dissolved in water is immediately decomposed into oxygen. Further, ozone dissolved in water is immediately released into the atmosphere.

  The present inventors have discovered that by generating microbubbles in water in which ozone is dissolved, the ozone concentration of ozone water can be maintained high over a long period of time, and an invention relating to an apparatus for producing ozone water has been filed so far. (For example, refer to JP2012-101222A).

  When water obtained by generating microbubbles in water in which ozone is dissolved (hereinafter, such water may be referred to as “microbubble ozone water”) is used for cleaning semiconductors, it is extremely high. The present inventors have confirmed that a cleaning effect can be obtained.

  However, when the conventional ozone water production apparatus is applied to the semiconductor cleaning process, there are the following problems.

  In a conventional ozone water production apparatus, a metal material is used in a wetted part such as a pipe, a tank, a valve, or a pump, and metal ions may be eluted in water. Further, metal debris generated at the sliding portion, foreign matter generated due to metal corrosion, etc. may be mixed in the water. Therefore, it is difficult to apply ozone water manufactured using a conventional ozone water manufacturing apparatus to a semiconductor cleaning process that requires extremely high cleanliness.

  Moreover, in the conventional ozone water manufacturing apparatus, ozone is sucked together with water by a centrifugal pump (for example, a spiral pump), and water and ozone are mixed by the stirring force of the impeller. However, since a metal material is used for the shaft portion of the impeller of the centrifugal pump, it has been difficult to avoid the problem of contamination of the cleaning water due to elution of metal ions or contamination of foreign matters.

  This invention is made | formed in view of said problem, and it aims at providing the washing | cleaning apparatus which can obtain the washing | cleaning liquid which has high cleanliness.

Means for solving the problems are the following inventions.
A dissolution tank for dissolving gas in a liquid;
A transfer pump for feeding liquid with gas into the dissolution tank;
An injection nozzle for injecting the liquid stored in the dissolution tank onto an object,
The transfer pump is a positive displacement pump;
The part that contacts the liquid of the dissolution tank, the transfer pump, and the injection nozzle is formed of a fluororesin,
A cleaning device comprising a heating device capable of heating the liquid.

  The heating device preferably heats the liquid to 40 ° C. or higher and 50 ° C. or lower.

  The discharge pressure of the spray nozzle is preferably higher than atmospheric pressure.

  The spray nozzle is preferably a microbubble generating nozzle.

  The gas is preferably ozone.

  The liquid is preferably water.

The transfer pump is a diaphragm pump,
It is preferable that the diaphragm of the diaphragm pump is formed of a fluororesin.

An injection pipe is installed inside the dissolution tank,
It is preferable that an injection hole for injecting the liquid sent by the positive displacement pump toward the inner wall of the dissolution tank is provided on the outer periphery of the injection pipe.

Two injection holes are provided on the outer periphery of the injection pipe,
The two injection holes are preferably provided at positions separated from each other by approximately 90 degrees on the outer periphery of the injection pipe.

  It is preferable that a gas discharge valve for discharging the gas accumulated in the dissolution tank to the outside is installed at the upper part of the dissolution tank.

A liquid level gauge for measuring the height of the liquid level of the liquid stored in the dissolution tank,
It is preferable to provide control means for controlling the gas discharge valve so that the height of the liquid level measured by the liquid level gauge is constant.

  It is preferable that the control means controls the gas discharge valve so that the height of the liquid level measured by the liquid level gauge is 1 mm or more and 20 mm or less from the upper bottom of the dissolution tank.

  The object is preferably a semiconductor wafer, a liquid crystal substrate, or a solar cell substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the washing | cleaning apparatus which can obtain the washing | cleaning liquid which has high cleanliness can be provided.

It is a flowchart of a washing | cleaning apparatus. It is a top view of a washing | cleaning apparatus. It is a front view of a washing | cleaning apparatus. It is a side view of a washing | cleaning apparatus. FIG. 2 is a cross-sectional view of the dissolution tank shown in FIG. It is sectional drawing of an injection nozzle. It is a flowchart of the washing | cleaning apparatus which concerns on another embodiment. It is sectional drawing which shows another example of an injection nozzle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a flowchart of the cleaning apparatus according to the present embodiment. FIG. 2 is a plan view of the cleaning device. FIG. 3 is a front view of the cleaning device. FIG. 4 is a side view of the cleaning device.

As shown in FIGS. 1 to 4, the cleaning device 10 includes a dissolution tank 20 for dissolving ozone (O ₃ ) in water, and a transfer pump 30 for feeding ozone (O ₃ ) into the dissolution tank 20 together with water. And an injection nozzle 40 for injecting water stored in the dissolution tank 20 onto the object W. The parts of the dissolution tank 20, the transfer pump 30, and the spray nozzle 40 that are in contact with water are made of fluororesin.

  The dissolution tank 20 is a cylindrical sealed tank formed of a steel material such as stainless steel, and the inside thereof can be held at a high pressure. All parts of the dissolution tank 20 that come into contact with water are made of fluororesin. Specifically, the entire inner surface of the dissolution tank 20 is made of fluororesin or is lined with fluororesin. Examples of the fluororesin include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), perfluoroalkoxy fluororesin (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), ethylene Tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), or the like can be used. Of these, polytetrafluoroethylene (PTFE) is preferred.

  The transfer pump 30 is not a non-positive displacement pump such as a centrifugal pump but a positive displacement pump. A positive displacement pump is a pump which raises the pressure of the liquid in the space by changing the volume of the space. The positive displacement pump includes a reciprocating type and a rotary type, and examples thereof include a diaphragm pump, a gear pump, a piston pump, and a plunger pump. Although any positive displacement pump can be used as the transfer pump 30 of the present invention, it is preferable to use a diaphragm pump.

  The portion of the transfer pump 30 that comes into contact with water is formed of a fluororesin. Specifically, at least the inner surface of the casing of the transfer pump 30 is lined with a fluororesin. Alternatively, the casing itself is made of a fluororesin. The operating member disposed inside the casing is also formed of a fluororesin. For example, when the transfer pump 30 is a diaphragm pump, the diaphragm is formed of a fluororesin. When the transfer pump 30 is a gear pump, the gear is formed of a fluororesin. When the transfer pump 30 is a piston pump, the piston is made of a fluororesin. When the transfer pump 30 is a plunger pump, the plunger is formed of a fluororesin. As the fluororesin, any of the fluororesins described above can be used, but polytetrafluoroethylene (PTFE) is preferably used.

  The injection nozzle 40 is a nozzle for injecting the cleaning water stored in the dissolution tank 20 onto the object W. In the present embodiment, a microbubble generating nozzle is used as the injection nozzle 40. By using the microbubble generating nozzle, bubbles (microbubbles) having a particle size of 1 to 50 μm, for example, can be generated in the cleaning water in which ozone is dissolved. Details of the injection nozzle 40 will be described later.

  By using the spray nozzle 40, microbubbles can be generated in the wash water in which ozone is dissolved. In this specification, the microbubble means, for example, a bubble having a particle size of 1 μm or more and 50 μm or less. The number of microbubbles in the liquid can be measured by, for example, a liquid particle counter “LiQuilaz-E20” manufactured by Particle Measuring Systems. For the measurement of the number of microbubbles in the liquid, it is preferable to use a light shielding liquid particle counter.

  All of the bubbles generated by the injection nozzle 40 need not be microbubbles. Preferably, 30% or more, more preferably 50% or more, more preferably 70% or more, and most preferably 90% or more of the bubbles generated by the injection nozzle 40 are microbubbles.

Next, the overall configuration of the cleaning apparatus 10 will be described in detail.
As shown in FIGS. 1 to 4, the suction port of the transfer pump 30 is connected to the pure water tank 12 through a pipe 14. The transfer pump 30 can suck the pure water stored in the pure water tank 12 and send it to the dissolution tank 20.

  The suction port of the transfer pump 30 is also connected to an ozone generator (not shown) via a pipe 15 branched from the pipe 14. The transfer pump 30 can suck ozone generated by the ozone generator through the pipe 15. That is, the transfer pump 30 can suck ozone together with the pure water through the pipe 14 and the pipe 15. The sucked pure water and ozone are mixed inside the transfer pump 30 and then fed into the dissolution tank 20.

  Of the both ends of the pipe 14, the end opposite to the side connected to the transfer pump 30 is inserted into the pure water of the pure water tank 12. A cup 16 having one large opening in a trumpet shape is attached to the end of the pipe 14 on the side inserted into the pure water. The cup 16 can collect ozone gas blown into pure water. That is, the transfer pump 30 can not only suck ozone gas through the pipe 15 but also suck ozone gas blown into the pure water tank 12 through the pipe 17. The cup 16 is preferably formed of a fluororesin.

  An injection pipe 21 for injecting water fed by the transfer pump 30 toward the inner wall of the dissolution tank 20 is installed inside the dissolution tank 20. The injection pipe 21 is installed substantially vertically, and extends almost entirely from the lower bottom portion to the upper bottom portion of the dissolution tank 20. The upper end portion of the injection pipe 21 is closed. Two injection holes 22 a and 22 b are provided in a portion slightly below the upper end of the injection pipe 21. Details of the two injection holes 22a and 22b will be described later. The injection pipe 21 is preferably formed of a fluororesin.

  The discharge port of the transfer pump 30 is connected to the lower end portion of the injection pipe 21 via the pipe 18. The pure water and ozone gas boosted by the transfer pump 30 are supplied to the lower end portion of the injection pipe 21, and then toward the inner wall of the dissolution tank 20 from the two injection holes 22 a and 22 b formed in the upper portion of the injection pipe 21. Be injected. Note that, during the normal operation of the cleaning device 10, the two injection holes 22 a and 22 b are located below the liquid level 20 a of the dissolution tank 20.

  In addition, a liquid level gauge 23 capable of measuring the height of the liquid level 20 a of water stored in the dissolution tank is installed inside the dissolution tank 20. The liquid level gauge 23 may be of any type, but in this embodiment, a guide pulse type liquid level gauge is used. The portion of the liquid level gauge 23 that comes into contact with water is preferably formed of a fluororesin or lined with a fluororesin. Specifically, it is preferable that the contact (probe) that contacts the water of the level gauge 23 is covered with a fluororesin.

FIG. 5 is a cross-sectional view of the dissolution tank 20 shown in FIG.
As shown in FIG. 5, a liquid level gauge 23 is installed at the center of the dissolution tank 20, and an injection pipe 21 is installed at a position near the wall surface of the dissolution tank 20. On the outer periphery of the injection pipe 21, two injection holes 22 a and 22 b are provided at positions separated by approximately 90 degrees in the circumferential direction. From the two injection holes 22a and 22b, water and ozone gas are injected in directions different by approximately 90 degrees. By injecting water and ozone gas in directions different by approximately 90 degrees in this way, at least two swirling flows rotating in opposite directions are generated inside the dissolution tank 20. Thereby, since contact and stirring of water and ozone gas are accelerated | stimulated, more ozone gas can be dissolved in water.

  Further, water and ozone gas are injected from the injection pipe 21 in the direction opposite to the liquid level gauge 23, thereby preventing water and ozone gas from hitting the liquid level gauge 23 and affecting the measurement value of the liquid level gauge 23. Has been.

  A gas release valve 24 for releasing the ozone gas accumulated above the liquid level 20 a in the dissolution tank 20 to the outside is installed at the upper part of the dissolution tank 20. As the gas release valve 24, an air operated valve is preferably used. This is because when the solenoid valve is used, the metal part of the solenoid valve may corrode and foreign matter or the like may be mixed into the cleaning water in the dissolution tank 20.

As the gas release valve 24, an adjustment valve capable of adjusting the gas flow rate may be used, or an on-off valve whose opening degree can be switched only between 100% and 0% may be used.
As the gas release valve 24, for example, a ball valve, a ball valve, a diaphragm valve, or the like can be used. Among these, it is preferable to use a diaphragm valve. Further, as the gas release valve 24, it is preferable to use a valve in which a pipe portion is formed of a fluororesin.

  As shown in FIG. 1, the cleaning apparatus 10 includes a control unit 60. The control means 60 is electrically connected to the gas discharge valve 24 and the liquid level gauge 23. The control means 60 can control the gas discharge valve 24 so that the height of the liquid level 20a measured by the liquid level gauge 23 is constant. Specifically, the control means 60 compares the height of the liquid level 20a measured by the liquid level gauge 23 with a preset target value, and controls the gas release valve 24 based on the comparison result. As the control means 60, a known control device capable of controlling an actuator such as a valve can be used, and for example, a sequencer can be used.

For example, when the height of the liquid level 20a measured by the liquid level gauge 23 is significantly higher than the target value (HH), the gas release valve 24 is completely closed (opening degree 0%). When the height of the liquid level 20a measured by the liquid level gauge 23 is higher than the target value (H), the gas release valve 24 is closed to some extent (opening degree 30%). When the height of the liquid level 20a measured by the liquid level gauge 23 is lower than the target value (L), the gas release valve 24 is opened to some extent (opening degree 70%). When the height of the liquid level 20a measured by the liquid level gauge 23 is significantly lower than the target value (LL), the gas release valve 24 is completely opened (opening degree 100%).
In addition, although the example of the control method of the gas discharge valve 24 was shown, you may control the gas discharge valve 24 by another method.

  As shown in FIG. 1, the dissolution tank 20 is connected to the injection nozzle 40 via a pipe 25. Since the inside of the dissolution tank 20 is at a high pressure (for example, 0.4 MPa) by the transfer pump 30, the cleaning water is ejected vigorously from the ejection nozzle 40. The pressure inside the dissolution tank 20 can be adjusted by the discharge pressure of the transfer pump 30. Alternatively, the pressure inside the dissolution tank 20 can be adjusted by opening and closing the gas discharge valve 24.

  The pipes 14, 15, 17, 18, 25 for connecting a plurality of devices included in the cleaning apparatus 10 are made of a fluororesin. As the fluororesin, any of the fluororesins described above can be used, but polytetrafluoroethylene (PTFE) is preferably used.

FIG. 6 is a cross-sectional view of the injection nozzle 40.
As shown in FIG. 6, the injection nozzle 40 includes a cylindrical outer member 42 having one end closed by a wall 42a and the other end opened, and a cylinder having one end closed by a wall 44a and the other end opened. A cylindrical inner member 44 is provided. The inner diameter of the outer member 42 is larger than the outer diameter of the inner member 44. The inner member 44 is disposed in the outer member 42 so that its axis coincides.

  The injection nozzle 40 includes a connector 46 formed in a substantially cylindrical shape. One end 46 a of the connector 46 is connected to a pipe 25 having one end connected to the dissolution tank 20. A cylindrical recess 46 c is formed at the other end 46 b of the connector 46. The open end of the inner member 44 is fitted into the recess 46c. An end portion of the outer member 42 on the side where the outer member 42 is opened is fitted into the outer peripheral portion of the end portion 46 b of the connector 46. The outer member 42, the inner member 44, and the connector 46 are integrally assembled with each other by screwing or the like.

Inside the inner member 44, an orifice 48, three perforated plates 50a to 50c, and seven spacers 52a to 52g are arranged. These members are arranged in the order of the orifice 48, the spacer 52a, the spacer 52b, the spacer 52c, the spacer 52d, the porous plate 50a, the spacer 52e, the porous plate 50b, the spacer 52f, the porous plate 50c, and the spacer 52g from the upstream side. Yes.
In addition, although the example in which the three porous plates 50a-50c are arrange | positioned is shown, the number of perforated plates is not limited to three. For example, the number of perforated plates may be adjusted in the range of 1 to 6 according to the water quality and the like. By adjusting the number of perforated plates, it is possible to generate bubbles suitable for the intended work.

The orifice 48 is a disc having a predetermined thickness, and a hole is formed in the center thereof.
The spacers 52a, 52e, and 52f are discs having a predetermined thickness (for example, 2.0 mm).
The spacers 52b, 52c, 52d, and 52g are discs having a predetermined thickness (for example, 1.0 mm).
The perforated plates 50a and 50c are discs having a plurality of small holes (for example, φ1.0 mm).
The perforated plate 50b is a disc having a plurality of small holes (for example, φ0.5 mm).
The spacer is preferably installed between the perforated plate and the perforated plate. It is preferable to provide a space of at least 0.5 mm between the perforated plate and the perforated plate. A space of 3 mm to 5 mm can be provided between the perforated plate and the perforated plate. By providing a space between the perforated plate and the perforated plate, bubbles can be generated efficiently.

  These parts constituting the injection nozzle 40 are preferably made of a fluororesin. That is, the outer member 42, the inner member 44, the connector 46, the orifice 48, the three porous plates 50a to 50c, and the seven spacers 52a to 52g are preferably made of a fluororesin. As the fluororesin, any of the fluororesins described above can be used, but polytetrafluoroethylene (PTFE) is preferably used.

  A first pressure release chamber 54 is formed between the wall 44 a of the inner member 44 and the spacer 52 g, and a plurality of through holes 56 are formed in the peripheral wall of the first pressure release chamber 54. A second pressure release chamber 57 is formed between the inner wall surface of the outer member 42 and the outer wall surface of the inner member 44. A substantially circular nozzle hole 58 for injecting water containing microbubbles is formed in the wall 42 a of the outer member 42.

Hereinafter, the mechanism by which micro bubbles are generated by the injection nozzle 40 will be described.
The water sent from the dissolution tank 20 through the pipe 25 passes through the orifice 48 after passing through the inside of the connector 46. Due to the pressure difference between the upstream and downstream of the orifice 48, part of the ozone dissolved in the water becomes bubbles and bubbles are generated.

  After passing through the orifice 48, the water passes through the perforated plate 50a, the perforated plate 50b, and the perforated plate 50c. These perforated plates have a plurality of small holes. The sizes of the small holes are φ1.0 mm, φ0.5 mm, and φ1.0 mm in order from the upstream side. That is, the sizes of the small holes in the adjacent perforated plates are different from each other.

  When water passes through the three perforated plates 50a to 50c, extremely complicated turbulent flow is generated in the water. Due to this turbulent flow, the bubbles are finely sheared, so that the particle size of the bubbles is reduced.

  Water passes through the three perforated plates 50 a to 50 c and then flows into the first pressure release chamber 54. The water that has flowed into the first pressure release chamber 54 then passes through a through hole 56 formed in the side wall of the first pressure release chamber 54. At this time, since the traveling direction of water changes by 90 degrees, the bubbles are further sheared by the turbulent flow.

  The water passes through the through hole 56 and hits the inner wall surface of the outer member 42. When water hits the inner wall surface of the outer member 42, the particle size of the bubbles is further reduced.

  Water collides with the inner wall surface of the outer member 42 and then flows into the second pressure release chamber 57. At this time, since the traveling direction of water changes by 90 degrees, the bubbles are further sheared by the turbulent flow.

  The water that has flowed into the second pressure release chamber 57 is jetted toward the object W from the nozzle hole 58. The water sprayed from the nozzle hole 58 contains bubbles (microbubbles) whose particle size is reduced to 1 to 50 μm by the mechanism described above.

Next, the operation and effect of the cleaning device 10 will be described.
In a conventional semiconductor cleaning apparatus, a metal material is used in a portion that comes into contact with water, such as a tank, a pipe, a valve, and a pump. For this reason, metal ions may be eluted in pure water, or foreign matter generated by metal corrosion may be mixed in the cleaning water.

  According to the cleaning apparatus 10 of the present embodiment, the portions of the dissolution tank 20, the transfer pump 30, and the spray nozzle 40 that are in contact with water are formed of fluororesin. Thereby, elution of metal ions and mixing of foreign substances are prevented, so that cleaning water with higher cleanliness can be obtained.

  Further, the portions of the pipes 14, 15, 17, 18, 25, the cup 16, the injection pipe 21, and the liquid level gauge 23 that are in contact with water are also formed of fluororesin. This more effectively prevents the cleaning water from being contaminated by the metal.

  Furthermore, when the transfer pump 30 is a diaphragm pump, the diaphragm is formed of a fluororesin. This more effectively prevents the cleaning water from being contaminated by the metal.

  The pure water sucked from the pure water tank 12 by the transfer pump 30 is sent to the dissolution tank 20. The inside of the dissolution tank 20 is maintained at a high pressure. Specifically, the pressure in the space 20b above the liquid level 20a of the dissolution tank 20 is maintained at 0.2 to 0.6 MPa, preferably 0.3 to 0.5 MPa, more preferably 0.4 MPa. . Thereby, a larger amount of ozone gas can be dissolved in water inside the dissolution tank 20. In addition, a larger amount of microbubbles can be generated in the injection nozzle 40.

  In order to increase the ozone concentration of the washing water, it is necessary to send an excessive amount of ozone gas to the dissolution tank 20 by the transfer pump 30. For this reason, ozone gas released from the water accumulates in the space 20b above the liquid level 20a of the dissolution tank 20.

  When the transfer pump 30 is, for example, a diaphragm pump, fluctuation (pulsation) occurs in the pressure of water transferred by the diaphragm pump. In this case, since the amount of cleaning water sprayed from the spray nozzle 40 is not constant, there is a problem that cleaning unevenness occurs when the cleaning water is used for cleaning a semiconductor wafer or the like. For this reason, in the conventional ozone water manufacturing apparatus, it was thought that a positive displacement pump (diaphragm pump) cannot be used as a pump for sending water and ozone into a tank.

  According to the cleaning apparatus 10 of the present embodiment, the space 20b is secured above the liquid level 20a of the dissolution tank 20, and pressure fluctuations caused by the transfer pump 30 can be absorbed by the space 20b. Therefore, even when a positive displacement pump is used as a pump for feeding water and ozone, the amount of cleaning water ejected from the ejection nozzle 40 is kept constant.

  The height of the liquid surface 20a of the dissolution tank 20 is 1 mm or more and 100 mm or less, preferably 1 mm or more and 70 mm or less, more preferably 1 mm or more and 50 mm or less, more preferably 1 mm or more and 30 mm or less from the upper bottom 20c of the dissolution tank 20. Preferably, it is maintained at 1 mm or more and 20 mm or less. When the height of the liquid level 20a is at a position higher than 1 mm from the upper base 20c, the volume of the space 20b is too small to sufficiently absorb the pressure fluctuation caused by the transfer pump 30. When the height of the liquid level 20a is lower than 100 mm from the upper base 20c, the volume of the space 20b is too large, so that it is difficult to control the flow rate of the cleaning water sprayed from the spray nozzle 40 to be constant. Become.

  Therefore, the height of the liquid level 20a measured by the liquid level gauge 23 is 1 mm or more and 100 mm or less, preferably 1 mm or more and 70 mm or less, more preferably 1 mm or more and 50 mm or less. Further, it is preferable to control the gas release valve 24 so that it is more preferably 1 mm to 30 mm, and most preferably 1 mm to 20 mm. The method of controlling the gas discharge valve 24 so that the height of the liquid level 20a is constant is as described above.

  According to the cleaning apparatus 10 of the present embodiment, it is possible to spray cleaning water with extremely high cleanness onto the object W. The washing water contains microbubbles, and the microbubbles remain in the washing water for a long time. The cleaning effect by ozone and microbubbles is enormous, and the object W can be cleaned extremely highly.

FIG. 7 is a flowchart of a cleaning apparatus according to another embodiment of the present invention.
The cleaning device 11 shown in FIG. 7 includes a return pipe 26 for returning the cleaning water stored in the dissolution tank 20 to the pure water tank 12. The end of the return pipe 26 is inserted into pure water stored in the pure water tank 12. An injection nozzle 41 for generating microbubbles is attached to the end of the return flow pipe 26 that is inserted into the pure water. The return pipe 26 and the injection nozzle 41 are made of a fluororesin.

  According to the cleaning device 11 shown in FIG. 7, the cleaning water stored in the dissolution tank 20 can be returned to the pure water tank 12 through the return pipe 26. Thus, the cleaning water can be circulated between the dissolution tank 20 and the pure water tank 12 until the concentration of the gas in the cleaning water or the concentration of the microbubbles reaches a predetermined value.

  As shown in FIG. 7, a heating device 27 for heating the cleaning water may be installed in the middle of the pipe 25. The washing water sent to the injection nozzle 40 can be heated to an arbitrary temperature by the heating device 27. The heating device 27 can be constituted by, for example, an electric heater. The warming device 27 can warm the cleaning water containing ozone to, for example, 30 ° C. to 60 ° C., preferably 40 ° C. to 50 ° C. By heating the cleaning water containing ozone, the cleaning power of the cleaning water can be further increased.

  FIG. 8 is a cross-sectional view showing another example of the injection nozzle. The injection nozzle 100 shown in FIG. 8 may be used instead of the above-described injection nozzle 40.

  An injection nozzle 100 shown in FIG. 8 includes a cylindrical main body 102. The main body 102 can be formed of the above-described fluororesin, but is preferably formed of PCTFE (polychlorotrifluoroethylene).

  Inside the cylindrical main body 102, an orifice 104, filters 106a to 106c, separation spacers 108a to 108c, and a fixed spacer 110 are arranged. These components are arranged in the order of the orifice 104, the separation spacer 108a, the filter 106a, the separation spacer 108b, the filter 106b, the separation spacer 108c, the filter 106c, and the fixed spacer 110 in order from the side where the cleaning water flows into the main body 102. Has been. These parts can be removed from the main body 102 and replaced.

  The orifice 104 is a disc having a predetermined thickness, and a circular hole is formed in the center thereof. The thickness of the orifice 104 is, for example, 3 mm. The diameter of the hole opened at the center of the orifice 104 is, for example, 0.5 mm. The orifice 104 can be formed of the above-described fluororesin, but is preferably formed of PCTFE (polychlorotrifluoroethylene).

  The filters 106a to 106c are discs having a plurality of small holes. The diameter of the plurality of small holes is, for example, 0.5 mm. The pitch of the plurality of small holes is, for example, 1.5 mm. The thickness of the filters 106a to 106c is, for example, 3 mm. The filters 106a to 106c can be formed of the above-described fluororesin, but are preferably formed of PCTFE (polychlorotrifluoroethylene).

  The separation spacers 108a to 108c are discs having a predetermined thickness, and a circular hole is formed in the center thereof. The thickness of the separation spacers 108a to 108c is, for example, 0.4 mm. The diameter of the hole opened in the center of the separation spacers 108a to 108c is, for example, 8.0 mm. The separation spacers 108a to 108c can be formed of the above-described fluororesin, but are preferably formed of PTFE (polytetrafluoroethylene).

  The fixed spacer 110 is a disc having a predetermined thickness, and a circular hole is formed in the center thereof. The thickness of the fixed spacer 110 is, for example, 3.2 mm. The diameter of the hole opened in the center of the fixed spacer 110 is, for example, 8.0 mm. The fixed spacer 110 can be formed of the above-described fluororesin, but is preferably formed of PCTFE (polychlorotrifluoroethylene).

  The discharge pressure of the spray nozzle 100 that sprays the cleaning water is, for example, about 0.1 MPa. The discharge pressure of the injection nozzle 100 is preferably a pressure slightly higher than atmospheric pressure. By using the spray nozzle 100, more microbubbles can be generated in the cleaning water containing ozone, and the cleaning power of the cleaning water can be further increased.

  The cleaning device 10 is a device that cleans the object W with microbubble ozone water. Examples of the object W include, but are not limited to, a semiconductor wafer, a liquid crystal substrate, a solar cell substrate, a glass substrate, a mask blank, and the like that require a high degree of cleaning.

  The cleaning apparatus 10 of the present invention may be applicable to, for example, the medical field (internal cleaning, etc.) in addition to cleaning semiconductor wafers and the like. In addition, the cleaning device 10 of the present invention may be applicable to a cleaning device for the electronics industry that requires a very high degree of cleaning.

In the above-described example, the example in which the gas to be dissolved in water is ozone has been described. However, the present invention can be applied even when other gases are dissolved in water. For example, the present invention can be applied even if the gas dissolved in water is oxygen (O ₂ ), hydrogen peroxide (H ₂ O ₂ ), nitrogen (N ₂ ), hydrogen (H ₂ ), or the like. .

  In the above-described example, the liquid that dissolves the gas is water, but the present invention can also be applied to other liquids. For example, the present invention can be applied to liquids such as organic solvents, aqueous sulfuric acid solutions, aqueous ammonia solutions, and slurries.

  In the above-described example, an example in which the number of spray nozzles 40 provided in the cleaning device 10 is one is shown, but two or more spray nozzles 40 may be provided.

  In the above-described example, an example in which one cleaning device 10 is installed alone has been described. However, a plurality of cleaning devices 10 may be installed in parallel.

DESCRIPTION OF SYMBOLS 10, 11 Cleaning apparatus 12 Pure water tank 14,15,17,18,25 Piping 20a Liquid level 20b Space 20c Upper bottom 20 Dissolution tank 21 Injection pipe 22a, 22b Injection hole 23 Level gauge 24 Gas discharge valve 26 Return piping 27 Heating device 30 Transfer pump 40, 41 Injection nozzle 60 Control means 100 Injection nozzle W Object

Claims (13)

A dissolution tank for dissolving gas in a liquid;
A transfer pump for feeding liquid with gas into the dissolution tank;
An injection nozzle for injecting the liquid stored in the dissolution tank onto an object,
The transfer pump is a positive displacement pump;
The dissolution tank, the transfer pump, and the portion of the spray nozzle that is in contact with the liquid are formed of fluororesin,
A cleaning device comprising a heating device capable of heating the liquid.   The cleaning apparatus according to claim 1, wherein the heating device heats the liquid to 40 ° C. or more and 50 ° C. or less.   The cleaning apparatus according to claim 1, wherein a discharge pressure of the spray nozzle is higher than an atmospheric pressure.   The cleaning apparatus according to any one of claims 1 to 3, wherein the spray nozzle is a microbubble generating nozzle.   The cleaning apparatus according to any one of claims 1 to 4, wherein the gas is ozone.   The cleaning apparatus according to any one of claims 1 to 5, wherein the liquid is water. The transfer pump is a diaphragm pump,
The cleaning apparatus according to any one of claims 1 to 6, wherein a diaphragm of the diaphragm pump is formed of a fluororesin. An injection pipe is installed inside the dissolution tank,
The injection hole which injects the liquid sent by the said transfer pump toward the inner wall of the said dissolution tank in the outer periphery of the said injection pipe is provided in any one of Claims 1-7. Cleaning device. Two injection holes are provided on the outer periphery of the injection pipe,
The cleaning device according to claim 8, wherein the two injection holes are provided at positions that are substantially 90 degrees apart from each other on the outer periphery of the injection pipe.   The cleaning according to any one of claims 1 to 9, wherein a gas release valve for releasing the gas accumulated in the dissolution tank to the outside is installed at an upper portion of the dissolution tank. apparatus. A liquid level gauge for measuring the height of the liquid level of the liquid stored in the dissolution tank,
The cleaning apparatus according to claim 10, further comprising a control unit that controls the gas discharge valve so that a liquid level measured by the liquid level gauge is constant.   The said control means controls the said gas discharge valve so that the height of the liquid level measured by the said liquid level meter may be 1 mm or more and 20 mm or less from the upper bottom of the said dissolution tank, The washing | cleaning of Claim 11 apparatus.   The cleaning apparatus according to claim 1, wherein the object is a semiconductor wafer, a liquid crystal substrate, or a solar cell substrate.