JP2010082558A - Microbubble supplying apparatus and liquid treatment unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microbubble supplying apparatus which supplies microbubbles stably and uniformly to a member arranged in a liquid. <P>SOLUTION: The microbubble supplying apparatus which supplies microbubbles to the member arranged in a first liquid stored in a storing tank, is provided with: a gas supply part to supply a jetted gas into the first liquid; a liquid supply part to supply a jetted second liquid into the first liquid; a bubble refinement part which refines the gas supplied from the gas supply part to microbubbles, and produces and sends out a mixed fluid by mixing the microbubbles with the second liquid supplied from the liquid supply part; and a jetting pipe which has jetting apertures to jet the mixed fluid into the first liquid and which jets the mixed fluid in the gas refinement part into the first liquid through the jetting apertures from the lower part of the member. The jetting pipe has a holdback part which holds back the mixed fluid to jet the same into the first liquid through the jetting apertures. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a fine bubble supply device and a liquid processing device, and in particular, a fine bubble supply device and a liquid that can stably and uniformly supply fine bubbles to the surface of a member disposed in the liquid. The present invention relates to a processing apparatus.

  Conventionally, in a manufacturing process of a semiconductor device or a solar battery, in a water washing process or an etching process of a wafer or a substrate, these processes are performed while supplying bubbles to a cleaning liquid or an etching liquid through a diffuser plate. ing. In this way, by supplying bubbles to the cleaning liquid, the etching liquid, etc., the cleaning, etching reaction, etc. proceed efficiently (for example, see Patent Document 1).

JP 2008-84903 A

  However, in the above-described conventional technology, the bubbles that have come out in the liquid from the holes of the diffuser plate have a small buoyancy, so they do not rise immediately but grow together and grow and are supplied through the diffuser plate. The bubble diameter is large, especially when a hydrophobic Teflon (registered trademark) bubbler is used. Usually, in a wafer or substrate washing or etching process, a plurality of wafers or substrates are arranged vertically at a predetermined interval, for example, several millimeters, and bubbles are formed between the wafers and the substrate. It will pass with the etchant.

  Here, when the diameter of the bubble is large, the diameter of the bubble is larger than the distance between the wafers and the substrates, and it is difficult to pass between the wafers and the substrates. The bubbles having a large diameter try to pass between the wafers and the substrates while being deformed by colliding with the wafers and the substrates, but the impact of the bubbles on the wafers and the substrates is great. For this reason, in a thin wafer or substrate washing process or etching process, there is a problem that the collision of bubbles with the wafer or substrate causes the wafer or substrate to break or chip.

  In addition, bubbles rise between the wafers and between the substrates, making it difficult for the bubbles to pass through the wafer surface and the substrate surface arranged in the center of the array. The efficiency of renewing the liquid in is reduced. On the other hand, since bubbles easily pass on the surface of the wafer or substrate arranged at the end of the array, the efficiency of renewal of the liquid on the surface of the wafer or substrate by the cleaning liquid or etching liquid is good. For this reason, there is a problem in that the efficiency of liquid renewal on the surface is different between the wafer surface and the substrate arranged in the center of the array, and the degree of cleaning and etching with the liquid becomes uneven for each wafer and substrate. is there.

  In addition, once the air diffuser is clogged with impurities in the liquid, it becomes difficult to eliminate the clogging. As a result, bubbles are generated not from the entire surface of the air diffuser, but are uniformly formed on the wafer or substrate. There was also a problem that was not supplied.

  This invention is made in view of the above, Comprising: It aims at obtaining the fine bubble supply apparatus which can supply a fine bubble to the member arrange | positioned in the liquid stably and uniformly. .

  In order to solve the above-described problems and achieve the object, the fine bubble supply device according to the present invention is a fine device for supplying fine bubbles to a member arranged in a first liquid stored in a storage tank. It is a bubble supply device, wherein a gas supply unit that supplies a gas to be ejected into the first liquid, a liquid supply unit that supplies a second liquid to be ejected into the first liquid, and the gas supply unit The gas supplied from the above is made into fine bubbles, mixed with the second liquid supplied from the liquid supply unit to generate a mixed fluid, and sent to the bubble miniaturization unit, and the mixed fluid to the first liquid A jet pipe for jetting into the first liquid, and jetting the mixed fluid from the bubble refining portion into the first liquid from below the member through the jet hole; The jet pipe stops the mixed fluid and Having a stop part for ejecting the first liquid through the hole, characterized by.

  According to this invention, since the mixed fluid containing the fine bubbles is ejected into the liquid by the fluid force of the mixed fluid from the tubular-shaped ejection hole whose other end in the longitudinal direction is sealed, the member disposed in the liquid As a result, the microbubbles can be supplied stably and uniformly.

  Embodiments of a fine bubble supply device and a liquid processing device according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings.

Embodiment 1 FIG.
In liquid processing such as water washing processing and etching processing of wafers and substrates, the present inventors stably and uniformly microbubbles for a long period of time on wafers and substrates immersed in a processing tank that performs liquid processing. The method of supply was examined. Usually, a processing tank in which a wafer or a substrate is immersed has a rectangular parallelepiped shape with a certain width or depth dimension because a plurality of holding members (carriers) in which a certain number of wafers and substrates are placed are arranged. is there.

  In order to uniformly supply fine bubbles to a wafer or substrate immersed in such a processing tank, at least one or more ejection holes are opened in the bubble refining means for generating fine bubbles. It was found that it was effective to connect the jet tube and seal the downstream end of the jet tube. In addition, it has been found that it is effective to attach the bubble miniaturization apparatus to the processing tank in the opposite direction in order to supply the fine bubbles more uniformly to the wafer and the substrate in the processing tank.

  FIGS. 1-1 to 1-3 are schematic views for explaining a schematic configuration of a cleaning apparatus that is a liquid processing apparatus using the fine bubble supply device according to the first embodiment of the present invention. 1-1 is a schematic front view of the cleaning device, FIG. 1-2 is a schematic side view of the cleaning device viewed from the arrow X in FIG. 1-1, and FIG. 1-3 is a schematic diagram of the cleaning device 1-1. It is the upper surface schematic diagram seen from no arrow Y. A bubble refining unit 3 is connected to a processing tank 1 serving as a cleaning liquid storage unit via a gas-liquid two-phase fluid supply pipe 11 on the outside. The bubble refinement unit 3 includes a cleaning solution supply pipe 2 that supplies a cleaning solution from the cleaning solution supply unit 13 to the bubble refinement unit 3, a gas supply tube 8 that supplies a gas from the gas supply unit 14 to the bubble refinement unit 3, Is connected.

  A carrier support base 6 is disposed in the processing tank 1. Further, on the carrier support base 6, a carrier 5 that holds a wafer 4 to be cleaned in the processing tank 1 and on which a plurality of wafers 4 can be arranged is placed. For example, 10 to 100 wafers can be arranged on one carrier 5. Further, a cleaning liquid outflow pipe 9 and a drain 12 are connected to the processing tank 1.

  Further, a jet pipe 7 in which a jet hole 7 a is formed in a substantially cylindrical pipe is disposed in the processing tank 1 below the carrier support base 6. One end of the jet pipe 7 in the longitudinal direction is connected to the gas-liquid two-phase fluid supply pipe 11, and the gas-liquid two-phase fluid is supplied from the gas-liquid two-phase fluid supply pipe 11 to the jet pipe 7. . On the other hand, a tube sealing portion 10 is provided at the other end in the longitudinal direction of the jet tube 7 so that the gas-liquid two-phase fluid is blocked by the tube sealing portion 10. That is, it is a damming portion that dampens the gas-liquid two-phase fluid and ejects it into the cleaning liquid through the ejection hole 7a.

  The cleaning liquid supply pipe 2, the bubble refinement section 3, the jet pipe 7, the gas supply pipe 8, the pipe sealing section 10, the gas-liquid two-phase fluid supply pipe 11, the cleaning liquid supply section 13 and the gas supply section 14 constitute a fine bubble supply apparatus. Has been. Further, the cleaning liquid supply pipe 2 and the cleaning liquid supply unit 13 constitute a liquid supply unit that supplies the cleaning liquid ejected into the cleaning liquid in the processing tank 1.

  Next, the fine bubble supply device will be described in detail. Specific examples of the bubble refining unit 3 include an injector and the like, but the same applies even if a slit type, a porous plate type, an arrayed porous plate type, an ultrafine needle type, a membrane type, a pressure dissolution type, or a venturi type is used. The effect of can be obtained. Moreover, it is preferable to install the bubble refinement | purification part 3 in the side surface with a short bottom length among the side surfaces of the processing tank 1. FIG. In particular, when the processing tank 1 is a rectangular parallelepiped, the fine bubbles can be supplied into the processing tank 1 more uniformly by installing the bubble refining unit 3 on the side of the side of the processing tank 1 having a short bottom.

  The flow rate ratio G / L between the gas flow rate G and the liquid flow rate L supplied to the bubble refining unit 3 is preferably 0.05 to 5 in terms of volume ratio. When the flow rate ratio G / L is less than 0.05, fine bubbles can be generated in the bubble refining unit 3, but the amount of bubbles generated is reduced because the gas supply amount is too small, and the wafer 4 is cleaned. The effect cannot be obtained sufficiently. On the other hand, when the flow rate ratio G / L is larger than 5, the gas supply amount to the bubble refining unit 3 is too large, and the coalescence of the bubbles generated in the bubble refining unit 3 advances and the bubble diameter increases. Therefore, fine bubbles cannot be supplied, and the cleaning effect of the wafer 4 is reduced.

  In addition, you may add alcohol or alcohol derivative to ion-exchange water previously as a coalescence prevention agent which has the effect which prevents bubble coalescence. Examples of alcohols or alcohol derivatives include methanol, ethanol, ethylene glycol, isopropyl alcohol, 1-propanol, 1,3-propanediol, 1-butanol, 2-butanol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1-propanol, 2-methyl 2-propanol, 2-butene-1,4-diol, 2-methyl-1,3-propanediol, 1-pentanol, 2-pentanol (sec-amyl alcohol) ), 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol (isoamyl alcohol), 2-methyl-2-butanol (tert-amyl alcohol), 3-methyl-2-butanol, 2 , 2-Dimethyl-1-propanol (Neopentyl alcohol 1,5-pentanediol, 3-methyl-1,3-butanediol, 2-methyl-1,4-butanediol, 1-hexanol, 2-hexanol, 3-hexanol, 1,2-hexanediol, 1 , 3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 3, 4-hexanediol, 1,2,3-hexanetriol, 1,2,4-hexanetriol, 1,2,5-hexanetriol, 1,2,6-hexanetriol, 1,3,6-hexanetriol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-2-pentanol, 3-methyl-2-pentanol 2-methyl-3-pentanol, 2-methyl-2,4-pentanediol, 2-methyl-1,5-pentanediol, 1,2,6-hexanetriol, 1-heptanol, 2-heptanol, 3 -Heptanol, 4-heptanol, 5-heptanol, 6-heptanol, 7-heptanol, 8-heptanol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-3-pentanol 1,2-heptanediol 1,3-heptanediol, 1,4-heptanediol, 1,5-heptanediol, 1,6-heptanediol, 1,7-heptanediol, 2,3-heptanediol, 2,4-heptanediol, 2,5-heptanediol, 2,6-heptanediol, 2,7-heptanediol, 3,4-heptanediol , 3,5-heptanediol, 3,6-heptanediol, 3,7-heptanediol, etc. and isomers other than those listed above (those having the same carbon number and having a straight chain or side chain, the position of the OH group) Are different).

  Further, the liquid flow rate L per minute supplied to the bubble refining unit 3 is 1/100 or more of the effective volume of the processing tank 1 (the amount of liquid actually stored in the processing tank 1), 1/2 The following is preferable. When the liquid flow rate L per minute is less than 1/100 of the effective volume of the processing tank 1, the liquid flow rate L is too small and the wafer 4 is not efficiently cleaned. In addition, when the liquid flow rate L per minute is larger than ½ of the effective volume of the processing tank 1, the liquid flow rate is too large, the liquid in the processing tank 1 becomes turbulent, and the wafer 4 greatly vibrates. Therefore, it is not preferable.

  Next, the jet pipe 7 will be described. FIG. 2 is a schematic diagram for explaining the structure of the jet tube 7. FIG. 2A is a schematic cross-sectional view in a direction substantially perpendicular to the central axis of the jet tube 7, and FIG. 2B is a schematic cross-sectional view in a direction substantially parallel to the central axis of the jet tube 7. The jet pipe 7 needs at least one or more ejection holes 7a, and the shape may be circular, but an elliptical shape or a rectangular shape is preferable. By making the ejection hole 7 a elliptical or rectangular, fine bubbles can be easily ejected from the jet pipe 7. It is preferable that the interval between the ejection hole 7a and the ejection hole 7a be shortened or not within a range in which the mechanical strength of the jet pipe 7 can be ensured. By shortening the interval between the ejection hole 7a and the ejection hole 7a as much as possible, the length of the ejection hole 7a can be increased, and the fine bubbles can be easily ejected from the jet tube 7. Moreover, it is preferable that the cross-sectional shape of the jet tube 7 in a direction substantially perpendicular to the central axis is a circle or an ellipse. By having such a shape, the fluid can flow smoothly in the jet pipe 7.

  For example, when the ejection hole 7a has a rectangular shape and the distance between adjacent wafers 4 in the carrier 5 is about 2 mm to 3 mm, the length in the longitudinal direction of the ejection hole 7a is A, and the ejection hole B> A, 5 mm <A <the total length of the jet pipe 7 (A = the total length of the jet pipe 7) where B is the distance between the central portion in the longitudinal direction of 7a and the central portion in the longitudinal direction of the adjacent ejection hole 7a. In this case, B = 0) is preferable. By satisfying such a condition, for example, fine bubbles of about 1 mm to 3 mm can be easily supplied into the processing tank 1 uniformly. Further, when the length of the ejection hole 7a in the short direction is C, it is preferable that 0.1 mm <C <10 mm. By satisfying such a condition, for example, fine bubbles of about 1 mm to 3 mm can be easily supplied into the processing tank 1 uniformly.

  The opening ratio of the ejection holes 7 a is preferably 1% or more and 50% or less with respect to the entire peripheral area of the jet pipe 7. When the opening ratio of the ejection holes 7a is smaller than 1%, the resistance when the fine bubbles are ejected from the ejection holes 7a becomes too large, and the fine bubbles are not uniformly supplied into the treatment tank 1, which is not preferable. Moreover, when the opening rate of the ejection hole 7a is larger than 50%, the pressure in the jet pipe 7 is not uniform, and the fine bubbles are not uniformly supplied into the treatment tank 1, which is not preferable.

  As shown in FIGS. 2-1 and 2-2, there may be a plurality of ejection holes 7a, but it is preferable that the number is as large as possible. As the number of the ejection holes 7a increases, fine bubbles can be supplied into the processing tank 1 uniformly. In addition, when the mechanical strength of the jet pipe 7 or the like becomes a problem, the vertically downward ejection hole 7a may not be provided.

  As described above, the tube sealing portion 10 is provided at the other end of the jet tube 7. FIG. 3 shows the distance (cm) from the tank wall surface on the side where the bubble miniaturization part 3 is arranged in the jet pipe 7 and the axial direction of the jet pipe 7 of the gas-liquid two-phase fluid in the jet pipe 7. It is the characteristic view compared with the case where there is no pipe sealing part 10 in the other end of the jet pipe 7, and the case where there is no pipe sealing part 10 regarding the relationship with a flow velocity (henceforth only a flow velocity) (m / sec). Here, the ratio of the gas (air) flow rate G to the liquid (ion exchange water) flow rate L: G / L is 0.5, the length of the jet tube 7 is 100 cm, the inner diameter is 20 mm, and the liquid flow rate is 15 L / Minutes.

  As can be seen from FIG. 3, the flow rate becomes slower as the distance from the tank wall surface of the jet tube 7 becomes longer regardless of the presence or absence of the tube sealing portion 10 at the other end of the jet tube 7. The initial speed is 0.83 m / sec regardless of the presence or absence of the tube sealing portion 10. Further, the flow velocity in the case where there is the tube sealing portion 10 once decreases at a position where the distance from the tank wall surface of the jet tube 7 is short, and then gradually and gradually becomes uniform. The flow rate when the tube sealing part 10 is present is 0 m / second, but the flow rate when the tube sealing part 10 is not present is 0.44 m / second. The material of the jet tube preferably has a static contact angle of less than 90 ° C., and examples include vinyl chloride (heat resistant when the liquid temperature is high) and SUS.

  On the other hand, the flow velocity in the case where there is no tube sealing portion 10 gradually decreases, but is faster overall than in the case where there is a tube sealing portion 10. And when there is no pipe sealing part 10, since the flow speed is too high and the flow speed which moves in the jet pipe 7 becomes faster than the rising speed of a bubble, a fine bubble is not discharge | released from the ejection hole 7a of the jet pipe 7. Most of the fine bubbles flow out from the other end of the jet tube 7, and the fine bubbles cannot be uniformly supplied to the wafer 4 in the processing tank 1. That is, since the pipe sealing part 10 is provided at the other end of the jet pipe 7, the flow velocity in the jet pipe 7 can be kept low, and as a result, fine bubbles are uniformly discharged from the jet holes 7a of the jet pipe 7. The fine bubbles can be uniformly supplied to the wafer 4.

  In addition, as a method of tube sealing at the other end of the jet tube 7, it is only necessary to prevent the gas-liquid two-phase fluid from leaking from the tip of the jet tube, and the other end of the jet tube 7 is capped as the tube sealing portion 10. There are a method and a method of melting and sealing the tip of the tube.

  Moreover, it is preferable that the length of the jet tube 7 is a length that sufficiently protrudes from the carrier 5 when the treatment tank 1 is viewed from the upper surface. When the jet tube 7 does not protrude from the carrier 5 in the length direction, the fine tube cannot be uniformly supplied to all the wafers 4 because the jet tube 7 is too short. Moreover, when one bubble refinement | miniaturization part 3 is installed with respect to the processing tank 1 as shown in this Embodiment, it is generally preferable that the length of the jet pipe 7 shall be 100 cm or less. If the length of the jet tube 7 is longer than 100 cm, it becomes difficult to keep the pressure in the jet tube 7 constant even if the tube sealing portion 10 is provided, and fine bubbles cannot be uniformly supplied into the processing tank 1.

  Next, the operation of the cleaning apparatus will be described. In the present embodiment, the case where the wafer 4 is cleaned with ion-exchanged water will be described. However, the cleaning process of the cleaning apparatus is not limited to this. In the treatment tank 1, ion exchange water (first liquid) having a lower water level than the cleaning liquid outflow pipe 9 is stored in advance. First, ion-exchanged water (second liquid) is sent from the cleaning liquid supply unit 13 to the bubble refinement unit 3 via the cleaning liquid supply pipe 2, and air is fine from the gas supply unit 14 via the gas supply pipe 8. Sent to the conversion unit 3.

  In the bubble refining unit 3, the supplied air is refined to generate fine bubbles, and the fine bubbles are mixed with ion-exchanged water supplied via the cleaning liquid supply pipe 2 to generate a mixed fluid. This mixed fluid is a gas-liquid two-phase fluid, that is, a gas-liquid two-phase fluid composed of a microbubble phase (gas phase) and ion-exchanged water (liquid phase). The gas-liquid two-phase fluid is sent to the jet pipe 7 in the processing tank 1 through the gas-liquid two-phase fluid supply pipe 11 due to the fluid force when the ion exchange water (second liquid) is supplied. The

  Subsequently, when the gas-liquid two-phase fluid flows into the jet pipe 7, the gas-liquid two-phase fluid is washed in the treatment tank 1 from the ejection hole 7a opened in the jet pipe 7 by the fluid force of the gas-liquid two-phase fluid. Erupted inside. That is, ion exchange water and fine bubbles are simultaneously ejected from the ejection hole 7a opened in the jet pipe 7. As a result, ion exchange water and fine bubbles are uniformly supplied to the wafer 4 from the lower portion of the wafer 4, the ion exchange water on the surface of the wafer 4 flows, and the wafer 4 is cleaned.

  At that time, the other end of the jet pipe 7 is sealed by the pipe sealing portion 10, so that the flow velocity of the gas-liquid two-phase fluid in the jet pipe 7 becomes gentle and uniform, and the jet opened in the jet pipe 7. Fine bubbles are uniformly ejected from the holes 7a. As a result, fine bubbles are supplied to the wafer 4 from the lower part of the wafer 4 between the wafers 4 and outside the wafer 4 in a stable and substantially uniform manner, so that the ion exchange water on the surface of the wafer 4 is substantially uniform. The wafer 4 is cleaned substantially uniformly. In the carrier support 6, there is a space where the carrier 5 is installed, and the fine bubbles supplied from the jet tube 7 are supplied to the wafer 4 without stagnation.

  The fine bubbles rise between the wafers 4 and the outside of the wafers 4 and then are released to the atmosphere on the water surface. The ion-exchanged water after the washing out flows out from the washing liquid outflow pipe 9. In addition, the wafer 4 that has been cleaned is pulled up together with the carrier 5 and sent to the next step, and another carrier 5 is immersed in the processing bath 1. In this way, the cleaning of the wafer 4 proceeds, and when the cleaning is completed, the ion exchange water in the processing tank 1 is drained through the drain 12.

  As described above, according to the cleaning device according to the first embodiment, the gas-liquid two-phase fluid containing fine bubbles is caused to flow from the ejection hole 7a of the jet tube 7 to the treatment tank 1 by the fluid force of the gas-liquid two-phase fluid. Since the liquid is ejected into the cleaning liquid and quickly and reliably rises, clogging in the ejection holes 7a due to impurities in the cleaning liquid is prevented, and the fine bubbles are stably and uniformly distributed in the cleaning liquid in the processing tank 1. Can be supplied. Further, since the bubbles are ejected from the ejection holes 7a and reliably rise, the fine bubbles do not grow together and grow large, and the fine bubbles can be stably and uniformly supplied into the cleaning liquid in the processing tank 1. can do.

  Further, since the bubbles supplied in the cleaning liquid are fine bubbles, the bubbles can pass uniformly and surely between the wafers 4 and outside the wafer 4, and the surface of the wafer 4 resulting from the position of the wafer 4. There is no difference in the efficiency of renewing the cleaning liquid. As a result, the occurrence of variations in the degree of cleaning due to the position of the wafer 4 is prevented, and the wafer 4 can be cleaned evenly.

  Further, since the bubbles supplied into the cleaning liquid are fine bubbles, the impact of the bubbles on the wafer 4 can be alleviated, and cracks between the wafers 4, chipping of the wafers 4, and sticking between the wafers 4 can be suppressed.

  In the above description, the case where air is used as the gas to be supplied to the bubble refinement unit 3 has been described. However, the gas to be supplied to the bubble refinement unit 3 is not limited to this, and air, oxygen, nitrogen, ozone, hydrogen , Helium, argon, krypton, xenon, methane, and a gas containing at least one of propane can be supplied.

  In the above description, the case where ion-exchanged water is used as the cleaning liquid has been described. However, the cleaning liquid is not limited thereto, and a liquid containing at least one of ion-exchanged water, tap water, groundwater, reclaimed water, and pure water is supplied. can do. Further, different liquids may be used for the cleaning liquid stored in the processing tank 1 and the cleaning liquid supplied to the bubble miniaturization unit 3.

  In the above description, the one-through type cleaning example in which the cleaning liquid that once cleaned the wafer 4 is discharged from the cleaning liquid outflow pipe 9 is shown. However, the cleaning liquid may be circulated. In that case, you may process to a washing | cleaning liquid, such as filtration by a film | membrane etc., ion removal by an ion exchange resin.

Embodiment 2. FIG.
In the second embodiment, a method for more uniformly supplying fine bubbles into the processing tank 1 will be described. FIG. 4 is a schematic front view for explaining a schematic configuration of the cleaning apparatus according to the second embodiment. As shown in FIG. 4, the cleaning device according to the second embodiment has a configuration in which a gas supply amount control device 15 is arranged in the middle of the gas supply pipe 8 in the cleaning device according to the first embodiment. The gas supply amount control device 15 can control the gas supply amount to the bubble miniaturization unit 3 when the wafer 4 is cleaned by the cleaning device. That is, in the cleaning device according to the second embodiment, the gas supply amount control device 15 controls the gas supply amount to the bubble miniaturization unit 3, thereby allowing the gas (air) flow rate G and the liquid (ion exchange water) flow rate. Ratio with L: G / L can be varied.

  FIG. 5A is a schematic diagram illustrating how bubbles are generated from the jet tube 7 when the amount of gas supplied to the bubble refining unit 3 is small (G / L = 0.1). FIG. 5B is a schematic diagram illustrating how bubbles are generated from the jet tube 7 when the amount of gas supplied to the bubble refining unit 3 is large (G / L = 1.0). Here, the inner diameter of the jet tube 7 is 20 mm, and the liquid flow rate is 15 L / min.

  Even if the amount of gas supplied to the bubble refining unit 3 is small (G / L = 0.1) and large (G / L = 1.0), the fine bubbles are uniformly distributed from the jet tube 7. Is released. When the amount of gas supplied to the bubble refining unit 3 is small (G / L = 0.1), the bubble refining unit in the length direction of the jet pipe 7 is shown in FIG. The amount of fine bubbles released from the region close to 3 is large. On the other hand, when the amount of gas supplied to the bubble refining unit 3 is large (G / L = 1.0), the bubble refining unit in the length direction of the jet tube 7 is shown in FIG. The amount of fine bubbles released from a region far from 3 is large.

  FIG. 6 shows the distance (cm) from the tank wall surface on the side where the bubble miniaturization section 3 is arranged in the jet pipe 7 and the axial direction of the jet pipe 7 of the gas-liquid two-phase fluid in the jet pipe 7. It is the characteristic view compared with the case where G / L = 0.1 and the case where G / L = 1.0 about the relationship with the flow velocity (m / sec). Here, the inner diameter of the jet tube 7 is 20 mm, and the liquid flow rate is 15 L / min. The length of the jet tube 7 is 100 cm. The material of the jet tube preferably has a static contact angle of less than 90 ° C., and examples include vinyl chloride (heat resistant when the liquid temperature is high) and SUS.

  As can be seen from FIG. 6, when G / L = 0.1, the flow velocity rapidly decreases in the region close to the bubble refining portion 3 and then gradually decreases to zero at the tube sealing portion 10. . On the other hand, when G / L = 1.0, the flow rate gradually decreases and becomes zero at the tube sealing portion 10. That is, due to the change in the flow velocity in the jet tube 7, a difference in the amount of microbubbles generated in the length direction of the jet tube 7 occurs. Therefore, by controlling the gas supply amount to the bubble miniaturization unit 3 using the gas supply amount control device 15 as in the present embodiment, the generation amount of fine bubbles is controlled, and the fine bubbles are transferred to the wafer 4. On the other hand, it becomes possible to supply more uniformly. In particular, when the gas flow rate or the liquid flow rate supplied to the bubble miniaturization unit 3 is limited, by controlling the gas supply amount to the bubble miniaturization unit 3 as in the present embodiment, the wafer 4 is controlled. Thus, fine bubbles can be supplied efficiently and uniformly. The gas supply amount control device 15 may be automatically operated by controlling a predetermined gas flow rate with a timer or the like.

  As described above, according to the cleaning device according to the second embodiment, the gas-liquid two-phase fluid containing fine bubbles is caused to flow from the ejection hole 7a of the jet tube 7 to the treatment tank 1 by the fluid force of the gas-liquid two-phase fluid. Since the liquid is ejected into the cleaning liquid and quickly and reliably rises, clogging in the ejection holes 7a due to impurities in the cleaning liquid is prevented, and the fine bubbles are stably and uniformly distributed in the cleaning liquid in the processing tank 1. Can be supplied. Further, since the bubbles are ejected from the ejection holes 7a and reliably rise, the fine bubbles do not grow together and grow large, and the fine bubbles can be stably and uniformly supplied into the cleaning liquid in the processing tank 1. can do.

  Further, since the bubbles supplied in the cleaning liquid are fine bubbles, the bubbles can pass uniformly and surely between the wafers 4 and outside the wafer 4, and the surface of the wafer 4 resulting from the position of the wafer 4. There is no difference in the efficiency of renewing the cleaning liquid. As a result, the occurrence of variations in the degree of cleaning due to the position of the wafer 4 is prevented, and the wafer 4 can be cleaned evenly.

  Further, since the bubbles supplied into the cleaning liquid are fine bubbles, the impact of the bubbles on the wafer 4 can be alleviated, and cracks between the wafers 4, chipping of the wafers 4, and sticking between the wafers 4 can be suppressed.

  Further, according to the cleaning device of the second embodiment, the amount of fine bubbles generated in the bubble miniaturization unit 3 by controlling the gas supply amount to the bubble miniaturization unit 3 using the gas supply amount control device 15. Thus, the fine bubbles can be supplied more uniformly to the wafer 4.

Embodiment 3 FIG.
In the third embodiment, a wet etching apparatus that performs alkali wet etching on a wafer 4 as a liquid processing apparatus using the fine bubble supply apparatus according to the present invention will be described. FIG. 7 is a schematic front view for explaining a schematic configuration of the wet etching apparatus according to the third embodiment.

  A bubble refining unit 3 is connected to a processing tank 1 serving as an etching solution storage unit via a gas-liquid two-phase fluid supply pipe 11 on the outside. A gas supply pipe 8 that supplies gas from the gas supply unit 14 to the bubble refinement unit 3 is connected to the bubble refinement unit 3. In addition, an overflow tank 16 is provided in the processing tank 1, and an etchant circulation pump 17 is connected to the overflow tank 16 via an etchant circulation pipe 18, and further bubble miniaturization is performed via the etchant circulation pipe 18. Connected to the unit 3.

  A carrier support base 6 is disposed in the processing tank 1. On the carrier support base 6, a carrier 5 that holds a wafer 4 to be subjected to an etching process in the processing tank 1 and on which a plurality of wafers 4 can be arranged is placed. For example, 10 to 100 wafers can be arranged on one carrier 5. A drain 12 is connected to the processing tank 1.

  In addition, a jet pipe 7, which is a jet part in which a jet hole 7 a is formed in a substantially cylindrical pipe, is disposed in the treatment tank 1 below the carrier support base 6. One end of the jet pipe 7 in the longitudinal direction is connected to the gas-liquid two-phase fluid supply pipe 11, and the gas-liquid two-phase fluid is supplied from the gas-liquid two-phase fluid supply pipe 11 to the jet pipe 7. . On the other hand, a tube sealing portion 10 is provided at the other end in the longitudinal direction of the jet tube 7 so that the gas-liquid two-phase fluid is blocked by the tube sealing portion 10. Below the jet pipe 7, a heater 24 is disposed and connected to a heater power supply 31 via a heater wiring 30.

  Further, a sodium hydroxide (NaOH) supply pipe 23, an alcohol derivative supply pipe 27, and an ion exchange water supply pipe 28 are connected to the treatment tank 1. A sodium hydroxide (NaOH) storage tank 21 and a sodium hydroxide (NaOH) supply pump 22 are sequentially connected to the treatment tank 1 via a sodium hydroxide (NaOH) supply pipe 23. The alcohol derivative storage tank 25 and the alcohol derivative supply pump 26 are sequentially connected to the treatment tank 1 via an alcohol derivative supply pipe 27. Here, the alcohol derivative storage tank 25, the alcohol derivative supply pump 26, and the alcohol derivative supply pipe 27 constitute a coalescence inhibitor adding unit that adds a bubble coalescence inhibitor to the etching solution. In addition, it is preferable that the material of these component parts is heat resistance and alkali resistance, and SUS and a fluororesin are mentioned as a material used.

  A fine bubble supply device is constituted by the bubble refining unit 3, the jet pipe 7, the gas supply pipe 8, the pipe sealing part 10, the gas-liquid two-phase fluid supply pipe 11, the overflow tank 16, the etchant circulation pump 17 and the etchant circulation pipe 18. It is configured. The overflow tank 16, the etchant circulation pump 17, and the etchant circulation pipe 18 constitute a liquid supply unit that supplies the etchant sprayed into the etchant in the treatment tank 1.

  Next, the operation of the wet etching apparatus will be described. First, a predetermined amount of ion exchange water is introduced into the treatment tank 1 via the ion exchange water supply pipe 28. In addition, a predetermined amount of sodium hydroxide (NaOH) solution is supplied from the sodium hydroxide (NaOH) storage tank 21 to the treatment tank 1 via a sodium hydroxide (NaOH) supply pipe 23 by a sodium hydroxide (NaOH) supply pump 22. It is thrown. In addition, a predetermined amount of alcohol derivative is introduced from the alcohol derivative storage tank 25 into the treatment tank 1 via the alcohol derivative supply pipe 27 by the alcohol derivative supply pump 26. Thereby, an etching solution having a predetermined concentration is prepared. The etching solution overflowing from the processing tank 1 is stored in the overflow tank 16.

  The sodium hydroxide (NaOH) and the alcohol derivative supplied here are preferably liquids, but the solids may be supplied by dissolving them in ion-exchanged water or the like. May be.

  Subsequently, gas is supplied from the gas supply unit 14 to the etching solution in the processing tank 1 through the gas supply pipe 8. Then, the etchant stored in the overflow tank 16 is pumped out by the etchant circulation pump 17 through the etchant circulation pipe 18, and sent again to the processing tank 1 through the etchant circulation pipe 18 and circulated. . Further, the etching solution in the processing tank 1 is heated to a predetermined temperature by the heater 24.

  Subsequently, the gas is supplied from the gas supply pipe 8 to the bubble refining unit 3, and at the same time, the etching liquid in the overflow tank 16 is pumped out by the etching liquid circulation pump 17 and is supplied to the processing tank 1 through the etching liquid circulation pipe 18. Sent. At this time, in the bubble refining unit 3, the supplied gas is made into fine bubbles and mixed with the circulated etchant to generate a gas-liquid two-phase fluid containing fine bubbles. Then, the gas-liquid two-phase fluid generated in the bubble miniaturization unit 3 is supplied again to the processing tank 1 through the gas-liquid two-phase fluid supply pipe 11, whereby the etching solution is circulated.

  Next, two carriers 5 on which, for example, silicon wafers are arranged as wafers 4 are placed on a carrier support 6 in the processing tank 1 by a robot arm or the like. As a result, the wafer 4 is immersed in the etching solution, and the wet etching process is performed for a predetermined time. Thereafter, the wafer 4 is pulled up together with the carrier 5 from the processing tank 1 again by a robot arm or the like and sent to the next process. Thus, the wet etching of the wafer 4 for one batch is completed. The wafer 4 is preferably subjected to a damage etching process in advance. As the damage etching process, there is a method of immersing the wafer 4 in an alkaline reagent for a predetermined time.

  Subsequently, in the same manner as described above, the carrier 5 on which the unprocessed wafer 4 is disposed is put into the processing tank 1 by a robot arm or the like, and wet etching processing is sequentially performed. When the predetermined number of batches of wet etching processing are completed, the etching solution in the processing bath 1 is discharged through the drain 12, and a new etching solution is prepared in the processing bath 1 as described above. The number of batches is determined from the amount of silicon eluted from the wafer 4 into the etching solution. Further, the wet etching process time varies depending on the number of batches, and becomes longer as the number of batches increases.

  FIG. 8 is a schematic front view for explaining a schematic configuration of another wet etching apparatus according to the third embodiment. The wet etching apparatus shown in FIG. 8 has a configuration in which a gas supply amount control device 15 is arranged in the middle of the gas supply pipe 8 in the wet etching apparatus shown in FIG. The gas supply amount control device 15 can control the gas supply amount to the bubble miniaturization unit 3 when the wafer 4 is etched by the wet etching device. That is, in this etching apparatus, the gas supply amount control device 15 controls the gas supply amount to the bubble miniaturization unit 3, whereby the ratio of the gas (air) flow rate G to the liquid (ion exchange water) flow rate L: G / L can be varied. The gas supply amount control device 15 may be automatically operated by controlling a predetermined gas flow rate with a timer or the like.

  By controlling the gas supply amount to the bubble miniaturization unit 3 using the gas supply amount control device 15, the generation amount of fine bubbles can be controlled to supply the fine bubbles more uniformly to the wafer 4. It becomes possible. In particular, when the gas flow rate or the liquid flow rate supplied to the bubble miniaturization unit 3 is limited, by controlling the gas supply amount to the bubble miniaturization unit 3, the wafer 4 can be efficiently and uniformly applied. Fine bubbles can be supplied. Thereby, the etching of the wafer 4 can be performed stably and efficiently, and the wafer 4 in the processing tank 1 can be uniformly etched without unevenness. Further, since the bubbles are miniaturized, the impact due to the bubbles on the wafer 4 in the processing tank 1 can be reduced, and cracks between the wafers 4, chipping of the wafers 4 and sticking between the wafers 4 can be suppressed.

  As described above, according to the wet etching apparatus according to the third embodiment, the gas-liquid two-phase fluid containing fine bubbles is discharged from the ejection hole 7a of the jet tube 7 by the flow force of the gas-liquid two-phase fluid. 1 is quickly and surely raised and is prevented from being clogged in the ejection hole 7a due to impurities in the etching solution, and the fine bubbles are stabilized in the etching solution in the processing tank 1. Can be supplied uniformly. Further, since the bubbles are ejected from the ejection holes 7a and reliably rise, the fine bubbles do not grow together and grow large, and the fine bubbles remain stable and uniform in the etching solution in the processing tank 1. Can be supplied.

  Further, since the bubbles supplied in the etching solution are fine bubbles, the bubbles can pass between the wafers 4 and outside the wafers 4 uniformly and reliably, and the wafer 4 due to the arrangement position of the wafers 4 can be assured. There is no difference in the efficiency of renewing the etching solution on the surface. Thereby, the variation in the etching degree due to the arrangement position of the wafer 4 is prevented, and the wafer 4 can be etched uniformly.

  In addition, since the bubbles supplied into the etching solution are fine bubbles, the impact of the bubbles on the wafer 4 can be reduced, and cracks between the wafers 4, chipping of the wafers 4, and sticking between the wafers 4 can be suppressed.

  Further, by controlling the gas supply amount to the bubble refining unit 3 using the gas supply amount control device 15, the amount of fine bubbles generated in the bubble refining unit 3 can be controlled. It becomes possible to supply more uniformly.

Embodiment 4 FIG.
When the treatment tank 1 has a rectangular parallelepiped shape and the length of the bottom surface in the longitudinal direction (hereinafter referred to as the width dimension of the treatment tank 1) is long, for example, when the width dimension of the treatment tank 1 exceeds 100 cm It is difficult for one bubble miniaturizing unit 3 to uniformly supply fine bubbles into the processing tank 1. In such a case, it is possible to supply the fine bubbles uniformly into the processing tank 1 by installing the bubble refining unit 3 outside the both side surfaces in the width direction of the processing tank 1. In the fourth embodiment, a method for uniformly supplying fine bubbles into the processing tank 1 when the processing tank 1 has a rectangular parallelepiped shape and the processing tank 1 has a long width dimension will be described.

  FIG. 9 is a schematic front view for explaining a schematic configuration of the cleaning apparatus according to the fourth embodiment. As shown in FIG. 9, the cleaning apparatus according to the fourth embodiment is provided with a longer width of the processing tank 1 than the cleaning apparatus according to the first embodiment, and two bubble miniaturization units 3-1 and 3-2. Are arranged outside both side surfaces in the width direction of the processing tank 1 via gas-liquid two-phase fluid supply pipes 11-1 and 11-2, respectively. In addition, the bubble refining units 3-1 and 3-2 are connected to the gas supply unit 14 through gas supply pipes 8-1 and 8-2, respectively.

  The cleaning liquid supply pipe 2 connected to the cleaning liquid supply unit 13 is branched into two paths, and one path is connected to the bubble refining unit 3-1 via the flow rate adjustment valve 41-1. The other path is connected to the bubble refining unit 3-2 via the flow rate adjusting valve 41-2. A wafer 4 to be cleaned is placed in a carrier 5 in the processing tank 1, and the carrier 5 is placed on a carrier support 6. Further, a cleaning liquid outflow pipe 9 and a drain 12 are connected to the processing tank 1.

  In the treatment tank 1, the jet pipe 7-1 and the jet pipe 7-2, each having a jet hole 7 a, are respectively connected to the gas-liquid two-phase fluid supply pipes 11-1 and 11-2 below the carrier support base 6. Further, they are connected together via a jet pipe connection 20 at the approximate center in the treatment tank 1.

  Next, the operation will be described. In the present embodiment, the case where the wafer 4 is cleaned with ion-exchanged water will be described. However, the cleaning process of the cleaning apparatus is not limited to this. In the treatment tank 1, ion exchange water (first liquid) having a lower water level than the cleaning liquid outflow pipe 9 is stored in advance. First, ion exchange water (second liquid) is supplied from the cleaning liquid supply unit 13 via the cleaning liquid supply pipe 2. The ion-exchanged water supplied from the cleaning liquid supply unit 13 is branched before the flow rate adjusting valves 41-1 and 41-2, adjusted at an equal flow rate, and sent to the bubble refining units 3-1 and 3-2, respectively. . In addition, air is sent from the gas supply unit 14 to the bubble refining units 3-1 and 3-2 through the gas supply pipes 8-1 and 8-2.

  In each of the bubble refining units 3-1 and 3-2, the supplied air is refined to generate fine bubbles, and the fine bubbles are mixed into the ion exchange water supplied through the cleaning liquid supply pipe 2. To produce a mixed fluid. This mixed fluid is a gas-liquid two-phase fluid, that is, a gas-liquid two-phase fluid composed of a microbubble phase (gas phase) and ion-exchanged water (liquid phase). And the gas-liquid two-phase fluid produced | generated in the bubble refinement | purification part 3-1, 3-2 is from the fluid force at the time of ion-exchange water (2nd liquid) being supplied via the washing | cleaning-liquid supply piping 2. The gas-liquid two-phase fluid supply pipes 11-1 and 11-2 are sent to the jet pipes 7-1 and 7-2 in the processing tank 1, respectively.

  Subsequently, when the gas-liquid two-phase fluid flows into the jet pipes 7-1 and 7-2, the gas-liquid two-phase fluid is opened to the jet pipes 7-1 and 7-2 by the flow force of the gas-liquid two-phase fluid. The jetted hole 7a is jetted into the cleaning liquid in the processing tank 1. That is, ion exchange water and fine bubbles are simultaneously ejected from the ejection hole 7a opened in the jet pipe 7. As a result, ion exchange water and fine bubbles are uniformly supplied to the wafer 4 from the lower portion of the wafer 4, the ion exchange water on the surface of the wafer 4 flows, and the wafer 4 is cleaned.

  At that time, the jet pipe 7-1 and the jet pipe 7-2 are combined into one at the center in the processing tank 1 via the jet pipe joint 20, so that the inside of the jet pipe 7-1 and the jet pipe 7 are combined. -2 has a gentle and uniform flow velocity of the gas-liquid two-phase fluid, and fine bubbles are uniformly ejected from the ejection holes 7a formed in the jet pipes 7-1 and 7-2. In other words, the portion where the gas-liquid two-phase fluid collides in the jet pipe 7-1 and the jet pipe 7-2 dams the gas-liquid two-phase fluid and ejects the ion-exchanged water through the ejection hole 7a. Has been. As a result, fine bubbles are supplied to the wafer 4 from the lower part of the wafer 4 between the wafers 4 and outside the wafer 4 in a stable and substantially uniform manner, so that the ion exchange water on the surface of the wafer 4 is substantially uniform. The wafer 4 is cleaned substantially uniformly. In the carrier support 6, there is a space where the carrier 5 is installed, and the fine bubbles supplied from the jet tube 7 are supplied to the wafer 4 without stagnation.

  The fine bubbles rise between the wafers 4 and the outside of the wafers 4 and then are released to the atmosphere on the water surface. The ion-exchanged water after the washing out flows out from the washing liquid outflow pipe 9. In addition, the wafer 4 that has been cleaned is pulled up together with the carrier 5 and sent to the next step, and another carrier 5 is immersed in the processing bath 1. In this way, the cleaning of the wafer 4 proceeds, and when the cleaning is completed, the ion exchange water in the processing tank 1 is drained through the drain 12.

  In the above description, the flow rate adjusting valves 41-1 and 41-2 are used to control the amount of ion exchange water supplied to the bubble miniaturization units 3-1 and 3-2 to be equal. When two micronization units 3 are used and the supply gas flow rates to the two bubble micronization units 3 are equal, the flow rate adjustment valves 41-1 and 41-2 are not necessary.

  Moreover, in the above, although the case where the jet pipe 7-1 and the jet pipe 7-2 were put together into one through the jet pipe connection 20 in the center in the processing tank 1 was demonstrated, the jet pipe 7-1 and the jet flow The tube sealing portion 10 may be installed at the end of the tube 7-2 on the center side in the processing tank 1, and in this case, the same effect as described above can be obtained.

  However, as shown in FIG. 9, the one where the jet pipe 7-1 and the jet pipe 7-2 are combined into one through the jet pipe joint 20 at the center in the processing tank 1 is a gas-liquid two-phase. The gas-liquid two-phase fluid from both sides from the fluid supply pipe 11-1 side and the gas-liquid two-phase fluid supply pipe 11-2 side collides, so that the gas-liquid two-phase fluid is mixed in the jet pipe 7. It is further promoted, and the effect that the fine bubbles are supplied more uniformly into the treatment tank 1 is obtained. Further, the horizontal flow velocity distribution of the gas-liquid two-phase fluid in the jet pipe 7 becomes more uniform, and the effect that the fine bubbles are more uniformly supplied into the processing tank 1 is obtained. Further, the gas-liquid two-phase fluid supply pipes 11-1 and 11-2 may be connected by a single jet pipe 7 without using the jet pipe connection 20. In this case as well, the case is similar to the case through the jet pipe connection 20. The effect is obtained.

  In addition, if there is no restriction | limiting in the installation position of the bubble refinement | miniaturization part 3, even if the length of the width direction of the processing tank 1 is less than 50 cm, for example, two bubble refinement | purification parts 3-1 and 3-2 will be attached. Thus, the fine bubbles can be supplied into the processing tank 1 more uniformly.

  FIG. 10 is a schematic bottom view for explaining a schematic configuration of another cleaning apparatus according to the fourth embodiment. The cleaning apparatus shown in FIG. 10 basically has the same configuration as the cleaning apparatus shown in FIG. Hereinafter, features different from the cleaning apparatus illustrated in FIG. 9 will be described.

  In the cleaning apparatus shown in FIG. 10, the processing tank 1 has a rectangular parallelepiped shape, and the length of the bottom surface of the processing tank 1 (hereinafter referred to as the depth of the processing tank 1) is longer than that of the cleaning apparatus shown in FIG. It has been. The gas-liquid two-phase fluid supply pipes 11-1 and 11-2 are branched by the same number on the processing tank 1 side, and the gas-liquid two-phase fluid branched by the flow rate adjusting valve 42 corresponding to the number of branches. It arrange | positions in the middle of supply piping 11-1 and 11-2. Further, jet pipes 7-1 and 7-2 are arranged at the tip of each flow rate adjusting valve 42 via gas-liquid two-phase fluid supply pipes 11-1 and 11-2, and jet pipes 7 located in the same row. -1 and the jet pipe 7-2 are combined into one by the jet pipe joint 20.

  When the depth dimension of the treatment tank 1 which is a direction substantially orthogonal to the longitudinal direction of the jet pipe 7 is long, the jet pipes 7-1 and 7-2 are thus arranged in a direction substantially orthogonal to the longitudinal direction of the jet pipe 7. By arranging a plurality of rows, the fine bubbles can be supplied more uniformly into the processing tank 1. FIG. 10 shows an example in which the gas-liquid two-phase fluid supply pipe 11 is branched into three rows on the processing tank 1 side and the jet pipes 7 are installed in three rows.

  Further, for example, if the width dimension of the treatment tank 1 is 200 cm or less, the length of each jet tube 7-1, 7-2 is 100 cm or less, and the bubble refining units 3-1, 3-2 have a general processing capability. When it has, it can supply a fine bubble more uniformly in the processing tank 1. FIG.

  As described above, according to the cleaning apparatus according to the fourth embodiment, the gas-liquid two-phase fluid containing fine bubbles is caused to flow from the ejection hole 7a of the jet tube 7 to the treatment tank 1 by the fluid force of the gas-liquid two-phase fluid. Since the liquid is ejected into the cleaning liquid and quickly and reliably rises, clogging in the ejection holes 7a due to impurities in the cleaning liquid is prevented, and the fine bubbles are stably and uniformly distributed in the cleaning liquid in the processing tank 1. Can be supplied. Further, since the bubbles are ejected from the ejection holes 7a and reliably rise, the fine bubbles do not grow together and grow large, and the fine bubbles can be stably and uniformly supplied into the cleaning liquid in the processing tank 1. can do.

  Further, since the bubbles supplied in the cleaning liquid are fine bubbles, the bubbles can pass uniformly and surely between the wafers 4 and outside the wafer 4, and the surface of the wafer 4 resulting from the position of the wafer 4. There is no difference in the efficiency of renewing the cleaning liquid. As a result, the occurrence of variations in the degree of cleaning due to the position of the wafer 4 is prevented, and the wafer 4 can be cleaned evenly.

  Further, since the bubbles supplied into the cleaning liquid are fine bubbles, the impact of the bubbles on the wafer 4 can be alleviated, and cracks between the wafers 4, chipping of the wafers 4, and sticking between the wafers 4 can be suppressed.

  Moreover, according to the cleaning apparatus concerning Embodiment 4, since the jet pipe 7-1 and the jet pipe 7-2 are connected to one through the jet pipe connection 20 in the center in the processing tank 1, The flow velocity of the gas-liquid two-phase fluid in the jet pipe 7-1 and the jet pipe 7-2 becomes gentle and uniform, and fine bubbles are uniformly formed from the ejection holes 7a opened in the jet pipes 7-1 and 7-2. Erupts. Thereby, for example, even when the width dimension of the processing tank 1 exceeds 100 cm, the fine bubbles are stably and substantially evenly supplied between the wafers 4 and outside the wafer 4. Flows substantially evenly, and the wafer 4 can be cleaned substantially uniformly.

Embodiment 5 FIG.
In the fifth embodiment, a wet etching apparatus having a treatment tank 1 having a width dimension exceeding 100 cm will be described. FIG. 11 is a schematic front view for explaining a schematic configuration of the wet etching apparatus according to the fifth embodiment. The processing tank 1 has a width dimension of 1450 mm, a depth dimension of 400 mm, and a water depth of 300 mm. The case where the wafer 4 accommodated in the carrier 5 is subjected to alkali etching is shown. FIG. 12 is a top view of the processing tank 1 of the wet etching apparatus according to the fifth embodiment.

  As shown in FIG. 12, the processing tank 1 is provided with an overflow tank 16 along one side surface in the depth direction. The etchant circulation pump 17 is connected to the overflow tank 16 via an etchant circulation pipe 18. Further, the etching solution circulation pipe 18 is branched into two paths on the side opposite to the overflow tank 16, and one path is connected to the bubble refining unit 3-1 via the flow rate adjusting valve 41-1. The other path is connected to the bubble refining unit 3-2 via the flow rate adjusting valve 41-2.

  The two bubble refining units 3-1 and 3-2 are arranged outside both side surfaces in the width direction of the processing tank 1 through gas-liquid two-phase fluid supply pipes 11-1 and 11-2, respectively. In addition, the bubble refining units 3-1 and 3-2 are connected to the gas supply unit 14 through gas supply pipes 8-1 and 8-2, respectively.

  Further, in the treatment tank 1, the jet pipe 7-1 and the jet pipe 7-2, each having a jet hole 7a, are respectively provided below the carrier support base 6 in the gas-liquid two-phase fluid supply pipes 11-1, 11-. 2, and are combined together via a jet pipe connection 20 at the approximate center in the treatment tank 1. The other configuration is the same as that of the third embodiment shown in FIG. A gas supply amount control device 15 may be installed in the gas supply pipes 8-1 and 8-2.

  The operation of the wet etching apparatus is such that the gas is supplied from the gas supply unit 14 to the bubble refining units 3-1 and 3-2 through the gas supply pipe 8, and the etching solution stored in the processing tank 1 is etched. The liquid circulation pump 17 supplies the bubble refining units 3-1 and 3-2 through the etching liquid recirculation piping 18, and the gas refining units 3-1 and 3-2 through the gas-liquid two-phase fluid supply piping 11. The third embodiment is the same as the third embodiment except that it is supplied to the jet pipe 7-1 and the jet pipe 7-2.

  As described above, according to the wet etching apparatus according to the fifth embodiment, the gas-liquid two-phase fluid containing fine bubbles is caused to flow from the ejection hole 7a of the jet tube 7 by the flow force of the gas-liquid two-phase fluid. 1 is quickly and surely raised and is prevented from being clogged in the ejection hole 7a due to impurities in the etching solution, and the fine bubbles are stabilized in the etching solution in the processing tank 1. Can be supplied uniformly. Further, since the bubbles are ejected from the ejection holes 7a and reliably rise, the fine bubbles do not grow together and grow large, and the fine bubbles remain stable and uniform in the etching solution in the processing tank 1. Can be supplied.

  Further, since the bubbles supplied in the etching solution are fine bubbles, the bubbles can pass between the wafers 4 and outside the wafers 4 uniformly and reliably, and the wafer 4 due to the arrangement position of the wafers 4 can be assured. There is no difference in the efficiency of renewing the etching solution on the surface. Thereby, the variation in the etching degree due to the arrangement position of the wafer 4 is prevented, and the wafer 4 can be etched uniformly.

  In addition, since the bubbles supplied into the etching solution are fine bubbles, the impact of the bubbles on the wafer 4 can be reduced, and cracks between the wafers 4, chipping of the wafers 4, and sticking between the wafers 4 can be suppressed.

  Further, according to the wet etching apparatus according to the fifth embodiment, the jet pipe 7-1 and the jet pipe 7-2 are connected to each other through the jet pipe joint 20 at the center in the processing tank 1. The flow velocity of the gas-liquid two-phase fluid in the jet pipe 7-1 and the jet pipe 7-2 becomes gradual and uniform, and it is fine from the jet holes 7a opened in the jet pipes 7-1 and 7-2. Bubbles erupt. Thereby, even when the width dimension of the processing tank 1 exceeds 100 cm, for example, the fine bubbles are stably and substantially evenly supplied between the wafers 4 and outside the wafer 4, so that etching is performed on the surface of the wafer 4. The liquid flows substantially evenly, and the wafer 4 can be etched substantially uniformly.

Embodiment 6 FIG.
Embodiment 6 demonstrates the washing | cleaning apparatus which has the processing tank 1 whose width dimension exceeds 100 cm. FIG. 13 is a schematic front view for explaining the schematic configuration of the cleaning apparatus according to the sixth embodiment. The processing tank 1 has a width dimension of 1400 mm, a depth dimension of 400 mm, a water depth of 300 mm, and is stored in the carrier 5. In this case, the wafer 4 is washed with ion exchange water.

  The configuration and operation of the cleaning apparatus according to the embodiment are the same as those of the cleaning apparatus shown in FIG. 9 in the fourth embodiment, but the width of the processing tank 1 is as long as 1400 mm and is stored in five carriers 5. The difference is that the wafer 4 can be cleaned simultaneously. A gas supply amount control device 15 may be installed in the gas supply pipe 8.

  As described above, according to the cleaning device according to the sixth embodiment, the gas-liquid two-phase fluid containing fine bubbles is caused to flow from the ejection hole 7a of the jet tube 7 to the treatment tank 1 by the fluid force of the gas-liquid two-phase fluid. Since the liquid is ejected into the cleaning liquid and quickly and reliably rises, clogging in the ejection holes 7a due to impurities in the cleaning liquid is prevented, and the fine bubbles are stably and uniformly distributed in the cleaning liquid in the processing tank 1. Can be supplied. Further, since the bubbles are ejected from the ejection holes 7a and reliably rise, the fine bubbles do not grow together and grow large, and the fine bubbles can be stably and uniformly supplied into the cleaning liquid in the processing tank 1. can do.

  Further, since the bubbles supplied in the cleaning liquid are fine bubbles, the bubbles can pass uniformly and surely between the wafers 4 and outside the wafer 4, and the surface of the wafer 4 resulting from the position of the wafer 4. There is no difference in the efficiency of renewing the cleaning liquid. As a result, the occurrence of variations in the degree of cleaning due to the position of the wafer 4 is prevented, and the wafer 4 can be cleaned evenly.

  Further, since the bubbles supplied into the cleaning liquid are fine bubbles, the impact of the bubbles on the wafer 4 can be alleviated, and cracks between the wafers 4, chipping of the wafers 4, and sticking between the wafers 4 can be suppressed.

  Moreover, according to the cleaning apparatus concerning Embodiment 6, since the jet pipe 7-1 and the jet pipe 7-2 are connected to one through the jet pipe connection 20 in the center in the processing tank 1, The flow velocity of the gas-liquid two-phase fluid in the jet pipe 7-1 and the jet pipe 7-2 becomes gentle and uniform, and fine bubbles are uniformly formed from the ejection holes 7a opened in the jet pipes 7-1 and 7-2. Erupts. Thereby, for example, even when the width dimension of the processing tank 1 exceeds 100 cm, the fine bubbles are stably and substantially evenly supplied between the wafers 4 and outside the wafer 4. Flows substantially evenly, and the wafer 4 can be cleaned substantially uniformly.

Embodiment 7 FIG.
In the seventh embodiment, a case where the fine bubble supply device according to the present invention is applied to the manufacture of a solar power generation device will be described. In the third embodiment, the wet etching apparatus shown in FIG. 7 was used to etch the surface of the silicon wafer for forming the photovoltaic power generation apparatus, thereby forming a texture on the surface of the silicon wafer.

  The etching solution is prepared by adding 3-methyl-1,5-pentanediol at 2.5 g / L as an additive to a 3 wt% sodium hydroxide solution in which sodium hydroxide is dissolved in ion-exchanged water. did. The amount of the etching solution was 56 L, the temperature of the etching solution was 90 ° C., and the amount of the circulating etching solution was 1/8 of the amount of the etching solution per minute. Air was supplied from the gas supply unit 14 to the bubble miniaturization unit 3. The supply gas flow rate was 1/7 of the circulating etching solution amount.

  Then, two carriers each containing 50 silicon wafers having a size of 15 cm × 15 cm and a thickness of 200 μm were immersed in an etching solution, and the silicon wafer was subjected to a wet etching process for 400 seconds. Thus, the silicon wafer of Example 1 having a texture formed on the surface was produced.

  Further, as Comparative Example 1, a fluorine resin bubbler 43 made of a fluororesin is used instead of the bubble miniaturization portion 3 as shown in FIG. Carried out. Thus, a silicon wafer of Comparative Example 1 having a texture formed on the surface was produced.

  FIG. 15 shows the relationship between the wavelength (nm) and the light reflectance (average value of 50 silicon wafers) when the surfaces of the silicon wafers of Example 1 and Comparative Example 1 were scanned with light having a wavelength of 300 nm to 1200 nm. Indicates. FIG. 16 shows the reflectance (average value for 50 silicon wafers) of light having a wavelength of 700 nm on the surfaces of the silicon wafers of Example 1 and Comparative Example 1.

  From FIG. 15, it can be seen that the silicon wafer of Example 1 has a lower light reflectance in most of the wavelength region except for the vicinity of the wavelength of 1200 nm. Further, as can be seen from FIG. 16, the silicon wafer of Example 1 had a light reflectance of 5.2% lower. Therefore, it can be said that the wet etching method of Example 1 can form a texture more effectively than the wet etching method of Comparative Example 1.

  Next, a solar power generation device was produced using the silicon wafer that had been subjected to the wet etching process as described above. FIGS. 17A and 17B are diagrams illustrating a solar power generation device manufactured using the silicon wafer of Example 1 in which a texture is formed on the surface by the wet etching described above, and FIG. FIG. 17-2 is a top view of the photovoltaic power generation apparatus. 17-1 and FIG. 17-2 includes a silicon wafer 131 having an N layer 131a on the surface of the silicon wafer, and an antireflection film formed on the light-receiving surface side surface of the silicon wafer 131. 132, a light receiving surface side electrode 133 formed on the light receiving surface side surface (front surface) of the silicon wafer 131, and a back surface electrode 134 formed on the surface (back surface) opposite to the light receiving surface of the silicon wafer 131. Prepare.

  The light receiving surface side electrode 133 includes a grid electrode 133a and a bus electrode 133b. FIG. 17A shows a cross-sectional view in a cross section perpendicular to the longitudinal direction of the grid electrode 133a. The silicon wafer 131 is a 15 cm square photovoltaic power generation apparatus using a silicon wafer having a textured structure formed on the surface using the wet etching method of the first embodiment described above.

  Next, the process for manufacturing the solar power generation device shown in FIGS. 17A and 17B using the above-described silicon wafer will be described. In addition, since the process demonstrated here is the same as the manufacturing process of the solar power generation device using a general polycrystalline silicon wafer, it does not illustrate in particular.

The silicon wafer on which the wet etching process of Example 1 is completed is put into a thermal oxidation furnace and heated in the presence of phosphorus oxychloride (POCl ₃ ) vapor to form phosphorus glass on the surface of the silicon wafer. Phosphorus is diffused in the wafer to form an N layer 131a on the surface layer of the silicon wafer.

  Next, after removing the phosphorous glass layer of the silicon wafer in a hydrofluoric acid solution, a silicon nitride film (SiN film) is formed as an antireflection film 132 by plasma CVD, and a region where the light-receiving surface side electrode 133 is formed on the N layer 131a. Except for forming. The film thickness and refractive index of the antireflection film are set to values that most suppress light reflection. Note that two or more layers having different refractive indexes may be stacked. Further, the antireflection film 132 may be formed by a different film formation method such as a sputtering method.

  Next, a silver mixed paste is printed on the light receiving surface of the silicon wafer in a comb shape by screen printing, and an aluminum mixed paste is printed on the entire back surface of the silicon wafer by screen printing, followed by a baking process. Thus, the light receiving surface side electrode 133 and the back surface electrode 134 are formed. As described above, the photovoltaic power generation apparatus shown in FIGS. 17A and 17B is manufactured as the photovoltaic power generation apparatus of the first embodiment.

Next, the produced solar power generation device was actually operated, and the power generation characteristics were measured and evaluated. As a result, photoelectric conversion efficiency η (%), open circuit voltage Voc (V), short circuit current Isc (mA / cm ² ), fill factor F.V. F. Is shown in Table 1.

Moreover, as a photovoltaic power generation apparatus of Comparative Example 1, a 15 cm square photovoltaic power generation apparatus was produced using the silicon wafer of Comparative Example 1 described above. And the solar power generation device of this comparative example 1 was actually operated, and the power generation characteristics were measured and evaluated. As a result, photoelectric conversion efficiency η (%), open circuit voltage Voc (V), short circuit current Isc (mA / cm ² ), fill factor F.V. F. Is also shown in Table 1.

  As can be seen from Table 1, in the photovoltaic power generation apparatus according to Example 1, the photoelectric conversion efficiency η is 0.6% higher than the photovoltaic power generation apparatus of Comparative Example 1, and the photoelectric conversion efficiency is improved. . Thus, by using the silicon wafer having a texture formed on the wafer surface by the wet etching method according to the first embodiment, the photovoltaic power generation apparatus is configured, and the suppression of the surface reflection loss of the silicon wafer is successfully achieved. It has been found that this contributes to the improvement of photoelectric conversion efficiency.

  This is because the fine bubbles can be uniformly supplied into the etching tank by performing the etching process on the surface of the silicon wafer for forming the photovoltaic power generation device using the wet etching apparatus shown in FIG. This is because clogging does not occur at the sprayed portion, and etching can be performed stably and efficiently. Therefore, it can be said that a solar power generation device with high conversion efficiency can be manufactured by using a silicon wafer obtained by etching the wafer surface using the wet etching apparatus shown in FIG.

  In the present embodiment, the number of bubble miniaturization units 3 is one, but the same effect can be obtained even when two bubble miniaturization units 3 are used.

  As described above, the micro-bubble supply device according to the present invention is useful when supplying micro-bubbles stably and uniformly to the surface of a member arranged in a liquid.

It is a front schematic diagram for demonstrating schematic structure of the washing | cleaning apparatus using the fine bubble supply apparatus concerning Embodiment 1 of this invention. It is a side surface schematic diagram for demonstrating schematic structure of the washing | cleaning apparatus using the fine bubble supply apparatus concerning Embodiment 1 of this invention. It is an upper surface schematic diagram for demonstrating schematic structure of the washing | cleaning apparatus using the fine bubble supply apparatus concerning Embodiment 1 of this invention. It is a schematic diagram for demonstrating the structure of the fine bubble supply apparatus concerning Embodiment 1 of this invention, and is a cross-sectional schematic diagram in the direction substantially perpendicular | vertical to the central axis of a jet pipe. It is a schematic diagram for demonstrating the structure of the fine bubble supply apparatus concerning Embodiment 1 of this invention, and is a cross-sectional schematic diagram in the direction substantially parallel to the central axis of a jet pipe. It is a characteristic view which shows the relationship between the distance from the tank wall surface in a jet pipe, and the flow velocity of the jet pipe of the gas-liquid two-phase fluid in a jet pipe with and without the pipe sealing part in a jet pipe . It is a front schematic diagram for demonstrating schematic structure of the washing | cleaning apparatus concerning Embodiment 2 of this invention. It is a schematic diagram which shows a mode that a bubble generate | occur | produces from a jet pipe, when there is little supply amount of the gas to a bubble refinement | miniaturization part (G / L = 0.1). It is a schematic diagram which shows a mode that a bubble generate | occur | produces from a jet pipe, when there is much supply amount of the gas to a bubble refinement | miniaturization part (G / L = 1.0). It is a characteristic view which shows the relationship between the distance from the tank wall surface in a jet pipe, and the flow velocity of the jet pipe of the gas-liquid two-phase fluid in a jet pipe with and without the pipe sealing part in a jet pipe . It is a front schematic diagram for demonstrating schematic structure of the wet etching apparatus concerning Embodiment 3 of this invention. It is a front schematic diagram for demonstrating schematic structure of the other wet etching apparatus concerning Embodiment 3 of this invention. It is a front schematic diagram for demonstrating schematic structure of the washing | cleaning apparatus concerning Embodiment 4 of this invention. It is a lower surface schematic diagram for demonstrating schematic structure of the other washing | cleaning apparatus concerning Embodiment 4 of this invention. It is a front schematic diagram for demonstrating schematic structure of the wet etching apparatus concerning Embodiment 5 of this invention. It is a top view of the processing tank of the wet etching apparatus concerning Embodiment 5 of this invention. It is a front schematic diagram for demonstrating schematic structure of the washing | cleaning apparatus concerning Embodiment 6 of this invention. It is a schematic diagram which shows the structure of the wet etching apparatus which uses the fluororesin bubbler made from a fluororesin. It is a characteristic view which shows the relationship between the wavelength (nm) and the light reflectance in the surface of the silicon wafer of Example 1 and Comparative Example 1. It is a figure which shows the reflectance of the light of 700 nm in the surface of the silicon wafer of Example 1 and Comparative Example 1. FIG. It is sectional drawing which shows the solar power generation device produced using the wafer concerning Example 1. FIG. It is a top view which shows the photovoltaic apparatus produced using the wafer concerning Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing tank 2 Cleaning liquid supply piping 3, 3-1, 3-2 Bubble refinement | miniaturization part 4 Wafer 5 Carrier 6 Carrier support stand 7, 7-1, 7-2 Jet pipe 7a Ejection hole 8, 8-1, 8- 2 Gas supply pipe 9 Cleaning liquid outflow pipe 10 Pipe sealing part 11, 11-1, 11-2 Gas-liquid two-phase fluid supply pipe 12 Drain 13 Cleaning liquid supply part 14 Gas supply part 15 Gas supply amount control device 16 Overflow tank 17 Etching liquid Circulation pump 18 Etch solution circulation pipe 21 Sodium hydroxide (NaOH) storage tank 22 Sodium hydroxide (NaOH) supply pump 23 Sodium hydroxide (NaOH) supply pipe 25 Alcohol derivative storage tank 26 Alcohol derivative supply pump 27 Alcohol derivative supply pipe 28 Ion exchange water supply piping 30 Heater wiring 31 Heater power supply 41-1, 41 2 flow rate adjustment valve 42 flow regulating valve 43 fluororesin bubbler 50 silicon wafer 131 silicon wafers 131a N layer 132 antireflection film 133a grid electrode 133b bus electrode 133 light-receiving surface side electrode 134 back electrode

Claims (17)

A fine bubble supply device for supplying fine bubbles to a member disposed in a first liquid stored in a storage tank,
A gas supply unit for supplying a gas to be ejected into the first liquid;
A liquid supply section for supplying a second liquid to be ejected into the first liquid;
A bubble miniaturization unit that converts the gas supplied from the gas supply unit into fine bubbles and mixes it with the second liquid supplied from the liquid supply unit to generate and send a mixed fluid;
There is an ejection hole for ejecting the mixed fluid into the first liquid, and the mixed fluid from the bubble miniaturization portion is introduced into the first liquid from below the member through the ejection hole. A spouted jet tube,
With
The jet pipe has a damming portion that dams the mixed fluid and ejects the mixed fluid into the first liquid through the jet hole;
A fine bubble supply device characterized by the above. The jet pipe is sealed at an end portion of the mixed fluid flowing into the jet pipe by sealing an end portion on the opposite side to the inflow side of the mixed fluid in a central axis direction.
The fine bubble supply device according to claim 1. Gas supply amount control means for controlling the supply amount of the gas supplied from the gas supply unit to the bubble miniaturization unit;
The fine bubble supply device according to claim 1. The bubble refinement portions are respectively provided at both ends in the central axis direction of the jet pipe, and the mixed fluid introduced into the jet pipe is introduced into the jet pipe from both ends of the jet pipe so that the mixed fluid flows into the jet pipe. Being dammed in the middle of the jet tube,
The fine bubble supply device according to claim 1. A plurality of the jet pipes are provided along the direction of the central axis of the jet pipe, and the mixed fluid is introduced into the plurality of jet pipes from a bubble refinement unit;
The fine bubble supply device according to claim 1. The ejection hole has an elliptical shape or a rectangular shape;
The fine bubble supply device according to claim 1. The jet pipe has a circular or elliptical cross-sectional shape in a direction perpendicular to the central axis direction of the jet pipe;
The fine bubble supply device according to claim 1. A reservoir for storing the first liquid;
A holding unit for holding a member to be treated for liquid treatment using the first liquid in the first liquid;
A gas supply unit for supplying a gas to be ejected into the first liquid;
A liquid supply section for supplying a second liquid to be ejected into the first liquid;
A bubble miniaturization unit that converts the gas supplied from the gas supply unit into fine bubbles and mixes it with the second liquid supplied from the liquid supply unit to generate and send a mixed fluid;
The first fluid has an ejection hole for ejecting the mixed fluid into the first liquid, and the mixed fluid from the bubble refining unit is passed through the ejection hole from below the processing target member. A jet tube that erupts inside,
With
The jet pipe has a damming portion that dams the mixed fluid and ejects the mixed fluid into the first liquid through the jet hole;
A liquid processing apparatus. The jet pipe is sealed at an end portion of the mixed fluid flowing into the jet pipe by sealing an end portion on the opposite side to the inflow side of the mixed fluid in a central axis direction.
The liquid processing apparatus according to claim 8. Gas supply amount control means for controlling the supply amount of the gas supplied from the gas supply unit to the bubble miniaturization unit;
The liquid processing apparatus according to claim 8. The bubble refinement portions are respectively provided at both ends in the central axis direction of the jet pipe, and the mixed fluid introduced into the jet pipe is introduced into the jet pipe from both ends of the jet pipe so that the mixed fluid flows into the jet pipe. Being dammed in the middle of the jet tube,
The liquid processing apparatus according to claim 8. A plurality of the jet pipes are provided along the direction of the central axis of the jet pipe, and the mixed fluid is introduced into the plurality of jet pipes from a bubble refinement unit;
The liquid processing apparatus according to claim 8. The ejection hole has an elliptical shape or a rectangular shape;
The liquid processing apparatus according to claim 8. The jet pipe has a circular or elliptical cross-sectional shape in a direction perpendicular to the central axis direction of the jet pipe;
The liquid processing apparatus according to claim 8. Including a coalescence inhibitor addition unit for adding a foam coalescence inhibitor to the first liquid;
The liquid processing apparatus according to claim 8. The first liquid is a cleaning liquid for cleaning the surface of the member to be processed;
The liquid processing apparatus according to claim 8. The first liquid is an etching solution for etching the surface of the member to be treated;
The liquid processing apparatus according to claim 8.

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