JP2012035166A - Fluid ejecting nozzle and washing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid ejecting nozzle capable of efficiently generating minute bubbles in liquid and blowing liquid including the minute bubbles onto a surface of an object to be washed so as to achieve successful washing.SOLUTION: The fluid ejecting nozzle includes: a unit body 160 having a gas introduction port 164a and a gas ejecting face 163 with a gas ejecting port 164b formed thereon; and a liquid introduction part 161 provided in the unit body 160 and having a liquid passage 161a which is formed thereon and through which liquid is made to pass. A gas passage 164 and a cavity 162 to which the liquid passage 161a of the liquid introduction part 161 is connected are formed in the unit body 160. The gas ejecting face 163 of the unit body 160 is formed to have a bowl shape having a bottom face portion 163a where the gas ejecting port 164b is formed. A plurality of nozzle holes 165 opened in a bowl-shaped peripheral face portion 163b of the gas ejecting face 163 and continued from the cavity 162 are formed on the unit body 160.

Description

  The present invention relates to a fluid ejection nozzle that ejects a liquid that can be used as a cleaning liquid such as a liquid that contains fine bubbles, and a cleaning device that uses the fluid ejection nozzle.

  Conventionally, a nozzle that ejects a liquid containing fine bubbles has been proposed (see Patent Document 1). The nozzle (condensed flow nozzle) is supplied with a fluid containing fine bubbles (bubbles), and the fine bubbles in the fluid are crushed and spread in a plane so that the nozzles are further divided and further refined by surface tension. It has a fluid flow surface formed in a flow channel shape capable of forcibly deforming fluid. By supplying a fluid containing fine bubbles to such a nozzle (reduced flow nozzle), a fluid containing extremely fine bubbles can be generated and ejected.

JP 2003-245533 A

  By the way, in recent years, it has been considered to use a liquid containing these fine bubbles (fine bubbles) for processing such as cleaning of the surface of an object. According to this fine bubble-containing liquid, the electric potential at the interface between the fine bubble and the liquid promotes the cleaning effect and oxidation action, and the energy when the fine bubble attached to the object surface bursts is used to remove dirt from the object surface. It is said that it contributes, and good cleaning of the object surface can be expected. Therefore, it is desired to efficiently generate fine bubbles in the liquid and spray the liquid containing the fine bubbles on the surface of the object to be cleaned so that good cleaning can be expected.

  However, in the above-described nozzle (condensed flow nozzle), when a liquid containing fine bubbles is pumped, the fine bubbles in the liquid are crushed and spread in a plane, and then there is no external action and the surface tension is naturally increased. Therefore, it is difficult to efficiently generate fine bubbles in the liquid. In addition, since the nozzle (constricted flow nozzle) originally has a structure in which fine bubbles are ejected into the liquid, it is difficult to spray a liquid containing the fine bubbles on the surface of the object to be cleaned so that good cleaning can be expected. .

  The present invention has been made in view of such circumstances, so that fine bubbles can be efficiently generated in the liquid, and the liquid containing the fine bubbles can be expected to be satisfactorily cleaned on the surface of the object to be cleaned. A fluid ejection nozzle that can be sprayed is provided.

  Moreover, this invention provides the washing | cleaning apparatus using such a fluid ejection nozzle.

  The fluid ejection nozzle according to the present invention includes a unit main body having a gas introduction port for introducing gas, a gas ejection surface on which a gas ejection port for ejecting gas is formed, and a liquid that is provided in the unit main body and through which the liquid passes. A liquid introduction part formed with a passage, and the unit main body includes a gas passage connecting the gas introduction port and the gas ejection port, and a liquid in the liquid introduction part formed so as to surround the gas passage. A hollow portion communicating with the passage is formed, and the gas ejection surface of the unit body is formed in a mortar shape with a surface on which the gas ejection port is formed as a bottom portion, and the gas ejection surface is formed on the unit body. A plurality of nozzle holes that open from the mortar-shaped peripheral surface portion of the surface and continue from the cavity portion are formed.

  With such a configuration, when a high-pressure gas is supplied to the gas inlet of the unit body and a gas-dissolved liquid in which the gas is dissolved at a relatively high concentration is supplied to the liquid inlet, the mortar on the gas ejection surface High-pressure air is ejected from the gas ejection port formed in the bottom surface of the gas-like shape, and the gas-dissolved liquid passing through the liquid passage of the liquid introduction portion is temporarily accumulated in the cavity portion while the mortar-shaped peripheral surface of the gas ejection surface It ejects from a plurality of nozzle holes that open at the part. When the gas dissolved liquid is ejected from each of the plurality of nozzle holes, the pressure is released to generate fine bubbles in the liquid, and the gas ejected from the gas outlet and the fine bubbles ejected from the plurality of nozzle holes The liquid mixture is mixed to form a mist (fine particles). Thereby, the fine bubble-containing liquid comes out in the form of mist (particulate form) from the mortar-like gas ejection surface in the unit body.

  In the fluid ejection nozzle according to the present invention, the openings of the plurality of nozzle holes may be arranged in a circular shape at predetermined intervals on a mortar-shaped peripheral surface portion of the gas ejection surface.

  With such a configuration, the fine bubble-containing liquid can be ejected from the mortar-shaped circumferential surface portion of the mortar shape of the gas ejection surface of the unit body without deviation.

  Moreover, the fluid ejection nozzle which concerns on this invention WHEREIN: Each formation direction of these nozzle holes can be set as the structure used as the direction which deviates from the outward extension line from the said gas ejection port of the said gas passage.

  With such a configuration, the fine bubble-containing liquid ejected from the plurality of nozzle holes formed in the mortar-shaped peripheral surface portion of the gas ejection surface in the unit body is converted into the gas ejected from the gas ejection port through the gas passage. It comes out from the gas ejection surface so as to be caught from the outside.

  Further, in the fluid ejection nozzle according to the present invention, the formation direction of the plurality of nozzle holes is configured to sequentially change around the extended line outward from the gas ejection port of the gas passage. be able to.

  With such a configuration, the fine bubble-containing liquid ejected from the plurality of nozzle holes formed in the mortar-shaped peripheral surface portion of the gas ejection surface in the unit body is vortexed into the gas ejected from the gas ejection port through the gas passage. It will come out from the gas ejection surface as if it is wrapped.

  Furthermore, in the fluid ejection nozzle according to the present invention, each of the plurality of nozzle holes may be formed in a direction from the gas ejection port of the gas passage toward an outward extension line.

  With such a configuration, the fine bubble-containing liquid ejected from the plurality of nozzle holes formed in the mortar-shaped peripheral surface portion of the gas ejection surface in the unit main body is straight to the gas ejected from the gas ejection port through the gas passage. The air is ejected from the gas ejection surface.

  Further, in the fluid ejection nozzle according to the present invention, the formation direction of the plurality of nozzle holes is a direction toward the same point on the outer extension line from the gas ejection port of the gas passage extending from the gas ejection port. It can be.

  With such a configuration, the fine bubble-containing liquid ejected from the plurality of nozzle holes formed in the mortar-shaped peripheral surface portion of the gas ejection surface in the unit body is the same as the gas ejected from the gas ejection port through the gas passage. The gas is ejected from the gas ejection surface in such a manner that it is drawn linearly into the portion.

  The cleaning apparatus according to the present invention includes any one of the above-described fluid ejection nozzles, a gas-dissolved liquid generation mechanism that generates a gas-dissolved liquid by dissolving gas in the liquid, and a gas-dissolved liquid generated by the gas-dissolved liquid generation mechanism A liquid supply mechanism that supplies liquid to the liquid introduction part of the fluid ejection nozzle and a gas supply mechanism that supplies high-pressure gas to the gas introduction port of the fluid ejection nozzle are provided.

  With such a configuration, the gas-dissolved liquid generated by the gas-dissolved liquid generating mechanism is supplied to the liquid introduction portion of the fluid ejection nozzle, and high-pressure air is supplied from the gas supply mechanism to the gas introduction port of the fluid ejection nozzle. And high-pressure air is ejected from the gas ejection port formed in the mortar-shaped bottom surface portion of the gas ejection surface of the fluid ejection nozzle, and the gas dissolved liquid passing through the liquid passage of the liquid introduction part is temporarily stored in the cavity part. While ejecting from a plurality of nozzle holes opened at the mortar-shaped peripheral surface portion of the gas ejection surface. When the gas dissolved liquid is ejected from each of the plurality of nozzle holes, the pressure is released to generate fine bubbles in the liquid, and the gas ejected from the gas outlet and the fine bubbles ejected from the plurality of nozzle holes The liquid mixture is mixed to form a mist (fine particles). Thereby, the fine bubble-containing liquid comes out in the form of mist (fine particles) from the mortar-shaped gas ejection surface of the fluid ejection nozzle (unit main body). And the surface of the said to-be-cleaned object can be wash | cleaned by spraying the to-be-washed | cleaned object by spraying the fine bubble containing liquid which mists out from the said fluid ejection nozzle (fine particle form).

  According to the fluid ejection nozzle according to the present invention, when the high-pressure gas is supplied to the gas introduction port of the unit main body and the gas-dissolved liquid in which the gas is dissolved at a relatively high concentration is supplied to the liquid introduction portion, the gas ejection surface From each of the plurality of nozzle holes formed in the mortar-shaped peripheral surface portion, a liquid containing fine bubbles efficiently generated by releasing the pressure of the gas-dissolved liquid is ejected, and from the plurality of nozzle holes The fine bubble-containing liquid that is ejected is mixed with the high-pressure gas that is ejected from the gas outlet, and then comes out in the form of a mist (many fine particles). It will be possible to spray so that good cleaning can be expected.

  Further, according to the cleaning device of the present invention, the fluid ejection nozzle can efficiently generate fine bubbles in the liquid, and good cleaning of the liquid containing the fine bubbles on the surface of the object to be cleaned can be expected. Therefore, the object to be cleaned can be cleaned well.

It is a figure which shows the structure of the washing | cleaning apparatus which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the cross section of the fluid ejection nozzle (two fluid nozzle structure) used for the washing | cleaning apparatus shown in FIG. It is a top view which shows the state which looked at the fluid ejection nozzle from which AA line cross section becomes a cross section shown to FIG. 2A from the downward direction. It is a figure which illustrates the state where a bubble containing liquid jumps out from the fluid ejection nozzle shown to FIG. 2A and FIG. 2B. It is sectional drawing which shows the cross section of the other example of the fluid ejection nozzle used for the washing | cleaning apparatus shown in FIG. FIG. 4B is a plan view showing a state in which a fluid ejection nozzle having a cross section taken along line B-B shown in FIG. 4A is viewed from below. It is a figure which illustrates the state where a bubble containing liquid jumps out from the fluid ejection nozzle shown to FIG. 4A and 4B.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The cleaning apparatus according to the first embodiment of the present invention is configured as shown in FIG.

  1 includes a liquid storage tank 11, a first gas supply unit 13, a pump 14, a pressurization tank 15, a two-fluid nozzle 16 (fluid ejection nozzle), a second gas supply unit 18, and a gas flow rate adjustment valve. 23 and an actuator 19 for driving the gas flow rate adjusting valve 23. A liquid storage tank 11 for storing a liquid, for example, pure water DIW, and a pressurization tank 15 are connected by a transmission pipe 12, and a pump 14 is provided in the transmission pipe 12. A gas (for example, nitrogen gas, oxygen gas, etc.) from the first gas supply unit 13 is interposed between the liquid storage tank 11 of the transmission pipe 12 through which the pure water DIW from the liquid storage tank 11 passes and the pump 14. It is supplied via the on-off valve 20.

  Pure water DIW mixed with gas from the gas supply unit 13 (hereinafter referred to as “gas-containing liquid” as appropriate) is pumped by the pump 14 to the pressurizing tank 15 through the transmission pipe 12, and the gas-containing liquid is pressurized. It is temporarily stored in the tank 15. In the pressurization tank 15, the gas-containing liquid to be stored is pressurized, the gas in the gas-containing liquid is melted in the liquid, the gas concentration in the liquid is increased, and the gas dissolved in a state of being supersaturated or close thereto. A liquid is generated (gas dissolved liquid generation mechanism). Note that the pressure in the pressurizing tank 15 can be adjusted by the pressure regulator 21.

  The pressurization tank 15 and the two-fluid nozzle 16 are connected by a feed pipe 17 provided with a throttle valve 22, and the feed pipe 17 is maintained while the gas dissolved liquid in the pressurization tank 15 is kept pressurized. And is supplied to the two-fluid nozzle 16 through the throttle valve 22 (liquid supply mechanism). A gas (for example, air) from the second gas supply unit 18 is supplied to the two-fluid nozzle 16 via a gas flow rate adjustment valve 23 (gas supply mechanism). The opening amount of the gas flow rate adjusting valve 23 is adjusted by being driven by the actuator 19, and high-pressure gas from the second gas supply unit 18 is supplied to the two-fluid nozzle 16 at a flow rate corresponding to the opening amount. . The two-fluid nozzle 16 has a structure as described later, and mixes the gas-dissolved liquid supplied from the pressurizing tank 15 and the high-pressure gas from the second gas supply unit 18 to form a mist-like liquid ( A fine liquid particle) is ejected. The liquid ejected in the form of a mist from the two-fluid nozzle 16 is a liquid (microbubble-containing liquid) containing fine bubbles (microbubbles, micronanobubbles, nanobubbles) as described later.

  Below the two-fluid nozzle 16, a semiconductor wafer 50 as an object to be cleaned placed on the table 111 fixed to the rotating shaft 112 of the drive unit 113 is arranged. As a result, the fine bubble-containing liquid ejected in a mist form from the two-fluid nozzle 16 is sprayed on the surface of the rotating semiconductor wafer 50 as a cleaning liquid, and the surface of the semiconductor wafer 50 is cleaned by the fine bubble-containing liquid (cleaning liquid). The

  In FIG. 1, a single two-fluid nozzle 16 is disposed above the semiconductor wafer 50 that is the object to be cleaned, and the liquid containing fine bubbles is sprayed over the entire surface of the semiconductor wafer 50. In order to efficiently spray the fine bubble-containing liquid over the entire surface of the semiconductor wafer 50, a single two-fluid nozzle 16 can be moved in a plane parallel to the semiconductor wafer 50, or a plurality of two-fluid nozzles 16 can be provided. You may comprise so that it may arrange | position.

  The two-fluid nozzle 16 (fluid ejection nozzle) is configured as shown in FIGS. 2A and 2B.

  2A and 2B, the two-fluid nozzle 16 has a structure formed such that the liquid introduction part 161 protrudes from the side surface of the cylindrical unit main body 160. A gas ejection surface 163 is formed in the central portion of the lower surface of the unit main body 160 so as to be recessed in a mortar shape. The unit main body 160 is formed with a gas passage 164 that connects a gas inlet 164a formed on the upper surface of the unit main body 160 and a gas outlet 164b formed in the bottom surface portion 163a of the mortar-shaped gas ejection surface 163. The gas passage 164 has a relatively wide diameter at a predetermined portion on the gas introduction port 164a side, and becomes a narrow diameter from the middle and continues to the gas ejection port 164b. In this way, the gas passage 164 is narrowed from the gas inlet 164a toward the gas outlet 164b, so that the gas supplied to the gas inlet 164a is ejected from the gas outlet 164b at a high speed.

  An annular cavity (cavity cavity) 162 is formed in the unit main body 160 so as to surround the gas passage 164. A liquid passage 161 a is formed in the liquid introducing portion 161, and the liquid passage 161 a communicates with the cavity 162. The unit main body 160 has a plurality of nozzle holes 165 communicating with the cavity 162. The plurality of nozzle holes 165 are opened at the inclined peripheral surface portion 163b of the mortar-shaped gas ejection surface 163, and the openings of the plurality of nozzles 165 are circular with a predetermined interval from the circumferential surface portion 163b of the gas ejection surface 163. Is arranged. In addition, the formation direction of the plurality of nozzle holes 165 deviates from the extension line C outward from the gas ejection port 164b of the gas passage 164 (for example, the extension portion outward from the gas ejection port 164b of the center line of the gas passage 164). The direction, specifically, is set so as to change while sequentially turning around the extension line C (refer to FIG. 2B in particular).

  In the two-fluid nozzle 16 (fluid ejection nozzle) having such a structure, the end of the feed pipe 17 that continues from the pressurizing tank 15 is connected to the mouth of the liquid introducing section 161, and the pressurizing tank 15 (see FIG. 1). The gas dissolved liquid W maintained in a pressurized state is guided to the cavity 162 in the unit main body 160 through the liquid passage 161a. The gas-dissolved liquid W guided in a pressurized state in the cavity 162 is ejected from a plurality of nozzle holes 165 that are opened at a mortar-shaped inclined peripheral surface portion 163 a of the gas ejection surface 163. When the gas-dissolved liquid W is ejected from each nozzle hole 165, the pressure is released, and fine bubbles (called nano bubbles, micro nano bubbles, micro bubbles, etc. depending on the size) are generated in the liquid. Further, high-pressure gas (for example, air) from the second gas supply unit 18 is supplied from the gas introduction port 164 a of the unit main body 160 to the gas passage 164 through the gas flow rate adjustment valve 23. Then, a high-pressure gas having a flow rate corresponding to the opening degree of the gas flow rate adjusting valve 23 is ejected from the gas ejection port 164b formed on the bottom surface 163a of the mortar-shaped gas ejection surface 163 through the gas passage 164.

  As described above, the direction in which the plurality of nozzle holes 165 are formed is the extension line C outward from the gas outlet 164b of the gas passage 164a (for example, the extension portion outward from the gas outlet 164b of the center line of the gas passage 164). The liquid containing fine bubbles ejected from each of the plurality of nozzle holes 165 passes through the gas passage 164 as shown in FIG. 3. It passes through the gas ejected from the gas ejection port 164b in a vortex shape. Then, the fine bubble-containing liquid that is ejected from the plurality of nozzle holes 165 and spirally wound into and mixed with the ejected gas is divided by the ejected gas into a mist, and is also accelerated by the ejected gas. In this state, the gas blasts out from the mortar-shaped gas ejection surface 163 spreading outward.

  In this way, the liquid containing fine bubbles that mists out (fine particles) from the two-fluid nozzle 16 is sprayed onto the semiconductor wafer 50 placed on the rotating stage 111. Effective removal of dirt and particles adhering to the surface of the semiconductor wafer 50 by the action, oxidation, bursting energy, etc. of the many fine bubbles in the liquid containing fine bubbles adhering to the surface of the semiconductor wafer 50 Will be able to.

  According to the two-fluid nozzle 16 having the above-described structure, the gas-dissolved liquid (relatively high concentration gas is maintained in a high pressure state from each of the plurality of nozzle holes 165 formed in the peripheral surface portion 163b of the gas ejection surface 163. The liquid containing fine bubbles that are efficiently generated by releasing the pressure (dissolved) is ejected. In addition, the fine bubble-containing liquid that is vortexed and mixed with the gas ejected from the plurality of nozzle holes 165 and then ejected from the gas ejection port 164b through the gas passage 164 is divided by the ejected gas into a mist shape. As a result, the liquid is ejected from the mortar-shaped gas ejection surface 163 that spreads outward, so that the liquid containing fine bubbles can be sprayed evenly over a relatively wide portion E of the surface of the semiconductor wafer 50 as shown in FIG. It becomes. And the surface of the semiconductor wafer 50 can be satisfactorily cleaned by such a liquid containing fine bubbles.

  In the two-fluid nozzle 16 described above, the direction in which the plurality of nozzle holes 165 formed in the peripheral surface portion 163b of the gas ejection surface 163 is extended from the gas ejection port 164b of the gas passage 164a to the extended line C (for example, gas It is set so as to change while turning around the gas jet outlet 164b on the center line of the passage 164 sequentially (in particular, see FIG. 2B). Instead, it may be set in an arbitrary direction that deviates from the extension line C without going to the extension line C. Even in this case, the fine bubble-containing liquid ejected from the plurality of nozzle holes 165 does not go directly to the gas ejected from the gas ejection port 164b through the gas passage 164 but to the ejected gas. Since it is divided by the ejected gas in the form of being drawn in from the mist, it becomes a mist (fine particle), and it comes out from the mortar-shaped gas ejection surface 163 spreading outward, so that the semiconductor wafer 50 It becomes possible to spray the fine bubble-containing liquid on the relatively wide portion of the surface with less unevenness.

  Conversely, in the two-fluid nozzle 16, the formation direction of the plurality of nozzle holes 165 formed in the peripheral surface portion 163 b of the gas ejection surface 163 is as shown in FIGS. 4A, 4 </ b> B, and 5. It can also set to the direction which goes to the same point P on the outward extension line C from the gas jet nozzle 164b. In this case, the liquid containing fine bubbles ejected from each of the plurality of nozzle holes 165 seems to be drawn in a concentrated manner in the same portion (P portion) of the gas ejected from the gas ejection port 164b through the gas passage 164. become. Then, the fine bubble-containing liquid that is ejected from the plurality of nozzle holes 165 and drawn into and mixed with the ejected gas is divided by the ejected gas to form a mist, and a mortar-shaped gas ejection surface 163 that spreads outward. Jump out from.

  In this way, the fine bubble-containing liquid that is drawn and mixed in a concentrated manner in the same part of the gas that is ejected from the plurality of nozzle holes 165, ejected from the gas ejection port 164b through the gas passage 164, is ejected. Since it is divided by the gas and becomes mist-like and ejects from the mortar-like gas ejection surface 163, it is possible to concentrate the mist-like fine bubble-containing liquid on the semiconductor wafer 50 and spray it with a stronger momentum. Become. And the surface of the semiconductor wafer 50 can be satisfactorily cleaned by such a liquid containing fine bubbles.

  In the two-fluid nozzle 16 having the structure shown in FIGS. 4A, 4 </ b> B, and 5, the plurality of nozzle holes 165 are formed in a direction from the gas outlet 164 b of the gas passage 164 toward the same point P of the outward extension line C. However, instead of the same point P, it may be set in a direction toward a different point on the extension line C. Even in this case, the fine bubble-containing liquid ejected from the plurality of nozzle holes 165 is linearly drawn into the gas ejected from the gas ejection port 164b through the gas passage 164, and the ejected gas is collected. The mist-like microbubble-containing liquid is relatively strong with respect to the semiconductor wafer 50 that is the object to be cleaned. It becomes possible to spray.

  Although not described in detail, in the above-described cleaning device 100, the two-fluid nozzle 16 is changed by changing the flow rate of the high-pressure gas supplied to the two-fluid nozzle 16 by changing the rotation of the gas flow rate adjusting valve 23 by the actuator 19. From various experiments, it was found that the size of the fine bubbles contained in the fine bubble-containing liquid ejected in the form of mist (fine particles) can be changed.

  In the cleaning apparatus 100 described above, the surface of the semiconductor wafer 50 is cleaned as an object to be cleaned. However, the object to be cleaned is not limited to this and may be another object such as a glass substrate.

  The two-fluid nozzle 16 is supplied with a gas-dissolved solution in which a gas such as oxygen is dissolved at a high concentration while maintaining the high-pressure state. The two-fluid nozzle 16 is a gas in which a gas is dissolved at a high concentration. Of course, it is also possible to supply other types of liquid instead of the dissolved liquid, and to eject the liquid in the form of a mist.

  In the two-fluid nozzle 16 described above, the gas ejection surface 163 includes a bottom surface portion 163a and a mortar-shaped peripheral surface portion 163b, and the nozzle hole 165 is opened in the peripheral surface portion 163b. The peripheral surface portion 163b can be formed in another shape, for example, a cylindrical surface shape. In this case, each nozzle hole 165 can be formed obliquely downward.

DESCRIPTION OF SYMBOLS 11 Liquid storage tank 12, 17 Transmission pipe 13 1st gas supply part 14 Pump 15 Pressurization tank 16 Two-fluid nozzle (fluid ejection nozzle)
160 Unit main body 161 Liquid introduction part 161a Liquid passage 162 Cavity 163 Gas ejection surface 163a Bottom surface part 163b Peripheral surface part 164 Gas passage 164a Gas introduction port 164b Gas ejection port 165 Nozzle hole 18 Second gas supply part 19 Actuator 20 Open / close valve 21 Pressure Adjuster 22 Throttle valve 23 Gas flow rate adjustment valve 50 Semiconductor wafer (object to be cleaned)
100 Cleaning device 111 Table 112 Rotating shaft 113 Drive unit

Claims (7)

A unit main body having a gas introduction port for introducing gas; a gas ejection surface formed with a gas ejection port for ejecting gas; and a liquid introduction portion provided in the unit main body and having a liquid passage through which liquid passes. Have
The unit body is formed with a gas passage connecting the gas introduction port and the gas ejection port, and a hollow portion formed so as to surround the gas passage and communicating with the liquid passage of the liquid introduction portion,
The gas ejection surface of the unit body is formed in a mortar shape with the surface on which the gas ejection port is formed as a bottom surface portion,
The unit body is a fluid ejection nozzle having a plurality of nozzle holes which are opened at a mortar-shaped peripheral surface portion of the gas ejection surface and continue from the cavity.   2. The fluid ejection nozzle according to claim 1, wherein the openings of the plurality of nozzle holes are arranged in a circular shape at predetermined intervals on a mortar-shaped peripheral surface portion of the gas ejection surface.   3. The fluid ejection nozzle according to claim 1, wherein a direction in which each of the plurality of nozzle holes is formed is a direction deviating from a line extending outward from the gas ejection port of the gas passage.   The fluid ejection nozzle according to claim 3, wherein the formation direction of the plurality of nozzle holes changes while sequentially turning around an extended line from the gas ejection port of the gas passage.   3. The fluid ejection nozzle according to claim 1, wherein each of the plurality of nozzle holes is formed in a direction toward an outward extension line from the gas ejection port of the gas passage.   The fluid ejection nozzle according to claim 5, wherein the formation direction of the plurality of nozzle holes is a direction from the gas ejection port of the gas passage toward the same point on an outward extension line. A fluid ejection nozzle according to any one of claims 1 to 6;
A dissolved gas generation mechanism for generating a dissolved gas by dissolving a gas in a liquid; and
A liquid supply mechanism that supplies the gas-dissolved liquid generated by the gas-dissolved liquid generation mechanism to the liquid introduction part of the fluid ejection nozzle;
A cleaning apparatus comprising: a gas supply mechanism that supplies high-pressure gas to the gas inlet of the fluid ejection nozzle.

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