JP2009088079A - Substrate treatment device, two-fluid nozzle, and liquid droplet supply method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the atomization of the liquid droplets in a liquid droplet supply method for supplying liquid droplets of pure water formed with the collision of the pure water with nitrogen gas, a two-fluid nozzle for supplying the liquid droplets, and a substrate treatment device for applying substrate treatment with the liquid droplets supplied to a substrate. <P>SOLUTION: The pure water is discharged from a liquid discharge port 342 and the nitrogen gas is discharged from gas discharge ports 341, 343 provided in the form of holding the liquid discharge port 342 therebetween, to form the liquid droplets of the pure water with the collision of the pure water with the nitrogen gas. The nitrogen gas is discharged into a liquid flow of the pure water via two different passages so as to be held therebetween, to operate shearing force on the pure water. Additionally, the nitrogen gas is discharged perpendicularly to the liquid flow of the pure water even in both gas discharge passages, therefore further increasing the shearing force. As a result, the fine liquid droplets are formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a droplet supply method for forming and supplying liquid droplets by colliding a liquid and a gas, a two-fluid nozzle for supplying droplets, and a substrate process for supplying a droplet to a substrate to perform substrate processing It relates to the device. The substrate may be, for example, a semiconductor wafer, a photomask glass substrate, a liquid crystal display glass substrate, a plasma display glass substrate, an FED (Field Emission Display) substrate, an optical disk substrate, a magnetic disk substrate, an optical substrate It refers to various substrates such as magnetic disk substrates (hereinafter simply referred to as “substrates”).

  The manufacturing process of an electronic component such as a semiconductor device or a liquid crystal display device includes a step of repeatedly forming a fine pattern by repeatedly performing processes such as film formation and etching on the surface of the substrate. Here, in order to perform fine processing well, it is necessary to keep the substrate surface clean. Therefore, a substrate cleaning process is performed as necessary (see Patent Document 1). The invention described in Patent Document 1 includes a two-fluid nozzle that supplies droplets of a processing liquid generated by collision of a gas to a processing liquid (liquid) to a substrate. This two-fluid nozzle is a so-called external mixing type two-fluid nozzle, and an annular gas discharge port is formed around a circular liquid discharge port at the tip of the two-fluid nozzle. The two-fluid nozzle generates a droplet of the processing liquid by causing the gas discharged from the gas discharge port to collide with the processing liquid discharged from the liquid discharge port, and supplies the droplet to the substrate. Thereby, the particles (fine dirt) adhering to the substrate surface are removed from the substrate, and the substrate is cleaned.

  By the way, the following technical matters are known in the cleaning process using a two-fluid nozzle. The technical matter is that as the number of liquid droplets supplied to the substrate (hereinafter simply referred to as “droplet number”) increases, the rate at which particles are removed from the substrate (hereinafter referred to as “removal rate”) increases. It is to be. Therefore, based on this knowledge, it is possible to improve the removal rate by increasing the number of droplets by atomizing the liquid. Therefore, in order to increase the liquid atomization efficiency, the following two-fluid nozzle has been proposed. For example, in the two-fluid nozzle described in Patent Document 2, liquid and gas are each discharged from an annular discharge port (a double annular discharge port as a whole). Thereby, the liquid is atomized to increase the atomization efficiency of the liquid.

  In the two-fluid nozzle described in Patent Document 3, an annular liquid channel (intermediate annular channel) is formed around a central air channel formed at the center of the nozzle. An annular outer air channel (outer annular channel) is formed outside the annular liquid channel. Then, after the water (liquid) from the annular liquid channel collides with the air (gas) ejected from the central air channel, it collides with the air from the annular outer air channel and the tip of the two-fluid nozzle A droplet is ejected from an opening provided in the.

JP 2004-349501 A (FIG. 2) Japanese Patent Laying-Open No. 2005-288390 (FIG. 2) Japanese Patent No. 3382573 (FIG. 2)

  As described above, in the prior art, droplets are miniaturized by devising a liquid and gas discharge mode. However, in recent years, wiring patterns and the like formed on the surface of a substrate have been miniaturized, and as a result, there has been a demand for atomization of droplets that exceeds the prior art.

  The present invention has been made in view of the above problems, a droplet supply method for forming and supplying liquid droplets by colliding liquid and gas, a two-fluid nozzle for supplying droplets, and a droplet on a substrate An object of the present invention is to increase atomization of droplets in a substrate processing apparatus that supplies and performs substrate processing.

  In order to achieve the above object, a substrate processing apparatus according to the present invention includes a substrate holding unit that holds a substrate, and a two-fluid nozzle that supplies droplets to the substrate held by the substrate holding unit. A liquid discharge unit that discharges liquid from the liquid discharge port toward the substrate; and a liquid discharge unit that is provided so as to sandwich the liquid discharge port, and that forms liquid droplets by colliding gas with the liquid discharged from the liquid discharge port And a second gas discharge unit, wherein at least one of the first and second gas discharge units discharges the gas at right angles to the liquid flow of the liquid discharged from the liquid discharge port.

  The two-fluid nozzle according to the present invention is a two-fluid nozzle that supplies liquid droplets, and in order to achieve the above object, a liquid discharge section that discharges liquid from the liquid discharge port in the liquid droplet supply direction; At least one of the first and second gas discharge units, which is provided so as to sandwich the outlet, and includes a first gas discharge unit and a second gas discharge unit that form liquid droplets by colliding gas with the liquid discharged from the liquid discharge port Is characterized in that gas is discharged at right angles to the liquid flow of the liquid discharged from the liquid discharge port.

  The droplet supply method according to the present invention is a droplet supply method for supplying a liquid droplet formed by colliding a gas with a liquid in a predetermined direction. A first step of discharging in the supply direction and a second step of forming liquid droplets by discharging gas so as to sandwich the liquid discharged in two different gas discharge paths and in the droplet supply direction In the second step, at least one of the two gas discharge paths is characterized in that gas is discharged at right angles to the liquid flow of the liquid.

  In the invention thus configured (substrate processing apparatus, two-fluid nozzle and droplet supply method), the liquid is discharged in a predetermined direction, and gas is discharged through two different paths so as to sandwich the liquid, Liquid droplets are formed by the collision between the liquid and the gas. In this way, gas is discharged into the liquid flow of the liquid through two different paths, and a shearing force acts on the liquid. In addition, since the gas is discharged at right angles to the liquid flow of the liquid in at least one of the two gas paths, the shear force is further increased. As a result, fine droplets can be formed.

  Here, in order to increase the shearing force closely related to the atomization of the liquid droplets, the first and second gas discharge portions constituting the two-fluid nozzle both respond to the liquid flow of the liquid discharged from the liquid discharge port. It is desirable that the gas is discharged at a right angle.

  In the two-fluid nozzle, the first and second gas discharge ports and the liquid discharge port for discharging gas may be formed in an annular shape, and the first gas discharge port is provided inside the annular liquid discharge port, while the second The gas discharge port may be provided outside the annular liquid discharge port. For example, the first gas outlet, the liquid outlet, and the second gas outlet may be arranged concentrically. Thus, by forming the liquid discharge port in an annular shape, the slit diameter of the liquid discharge port can be reduced, and droplet formation is facilitated. Further, since the liquid discharge port is sandwiched between the inside and the outside by the annular gas discharge port, the liquid discharged from the liquid discharge port can be uniformly formed into droplets, and the droplets can be made uniform. .

  Further, when the gas discharged from the first gas discharge port located inside the annular liquid discharge port is discharged at a right angle to the liquid flow, the first gas discharge unit may be configured as follows. That is, the first gas discharge section is configured to be orthogonal to the first gas flow path and the first gas flow path for guiding the gas to the first gas discharge opening in parallel with the liquid discharge direction from the liquid discharge opening. It can comprise so that it may have a 1st guide member provided facing a gas discharge port, and guides the gas discharged from the 1st gas discharge port to all the directions orthogonal to a 1st gas flow path.

  On the other hand, when the gas discharged from the second gas discharge port located outside the annular liquid discharge port is discharged at right angles to the liquid flow, the second gas discharge unit may be configured as follows. That is, the second gas discharge unit has a second guide member that guides the gas to the liquid flow while changing the flow of the gas discharged from the second gas discharge port in a direction orthogonal to the liquid flow of the liquid. Can be configured.

  Further, the liquid discharge unit may be configured to have a plurality of liquid discharge ports. As a result, the liquid is separated into a plurality of liquids when discharged from the liquid discharge port, which is suitable for atomizing the droplets.

<Substrate processing system>
FIG. 1 is a plan layout view showing a substrate processing system equipped with an embodiment of a substrate processing apparatus according to the present invention. The substrate processing system is a single-wafer type substrate processing system used for cleaning processing for removing contaminants such as particles and various metal impurities attached to a substrate W such as a semiconductor wafer. The substrate processing system includes a substrate processing unit PS and an indexer unit ID coupled to the substrate processing unit PS. The indexer unit ID includes a cassette C that stores a plurality of substrates W (a FOUP (Front Opening Unified Pod) that accommodates a plurality of substrates W in a sealed state, a SMIF (Standard Mechanical Interface Face) pod, an OC (Open Cassette), etc. The indexer robot 11 is provided for unloading the substrates W to be processed one by one and loading the processed substrates W into the cassette C again. Each cassette C is provided with a plurality of shelves (not shown) for stacking and holding a plurality of substrates W in the vertical direction with minute intervals, and one substrate W is placed on each shelf. Can be held. Each shelf is in contact with the peripheral edge of the lower surface of the substrate W to hold the substrate W from below, and the substrate W is accommodated in the cassette C in a substantially horizontal posture.

  The substrate processing unit PS has a substrate transfer robot 12 disposed substantially in the center in plan view, and a frame 100 to which the substrate transfer robot 12 is attached. The frame 100 is provided with a plurality (four in this embodiment) of substrate processing apparatuses 10 so as to surround the substrate transfer robot 12. As will be described later, these substrate processing apparatuses 10 have the same configuration, and perform substrate cleaning with a spray-like cleaning liquid (droplets) discharged from a two-fluid nozzle.

  The substrate transfer robot 12 can transfer the substrate W to the four substrate processing apparatuses 10. The substrate transport robot 12 operates to receive the unprocessed substrate W from the indexer robot 11 arranged in the indexer unit ID and to deliver the processed substrate W to the indexer robot 11. For this reason, the unprocessed substrate W is carried into one of the substrate processing apparatuses 10 by the indexer robot 11 and the substrate transport robot 12 and subjected to the substrate cleaning process by the substrate processing apparatus 10, and the cleaned substrate W is a substrate. After being unloaded from the substrate processing apparatus 10 by the transfer robot 12, it is returned to the cassette C via the indexer robot 11.

<Substrate processing equipment>
FIG. 2 is a schematic side view showing an embodiment of the substrate processing apparatus according to the present invention. The substrate processing apparatus 10 includes a spin chuck 111 that rotatably supports a substrate, a cup 112 for preventing the scattering of cleaning liquid that can be moved up and down around the substrate W supported by the spin chuck 111, and a spin chuck. A two-fluid nozzle 301 that supplies a spray-like cleaning liquid in which a liquid and a gas are mixed to the substrate W supported by 111, and a moving mechanism 200 that moves the two-fluid nozzle 301 along the surface of the substrate W are provided.

  The spin chuck 111 is configured to rotate around an axis oriented in the vertical direction by driving a motor 121. The spin chuck 111 is provided with a plurality of support pins 122 on the base 120 as the “substrate holding means” of the present invention so that the substrate W can be held. Then, the two-fluid nozzle 301 is moved horizontally along the surface of the substrate W by the moving mechanism 200.

  The moving mechanism 200 includes a support arm 202 that supports the two-fluid nozzle 301 and a drive unit that rotates the support arm 202 around an axis 203. That is, the two-fluid nozzle 301 is supported by the tip of the support arm 202 at a position above the spin chuck 111. Further, the base end portion of the support arm 202 is connected to the upper end of the shaft 203 so as to be integrally rotatable. Then, the support arm 202 rotates around the shaft 203 when the motor 204 capable of forward and reverse rotation operates in response to a signal from the control unit 150. As a result, the two-fluid nozzle 301 moves horizontally between the standby position on the side of the anti-scattering cup 112 and the substrate W held by the spin chuck 111.

  Here, the arrangement state of the two-fluid nozzle 301 with respect to the substrate W is arbitrary, but the two-fluid nozzle 301 is set so that the supply direction of the droplets to the substrate W is substantially coincident with the normal direction of the surface of the substrate W. You may arrange. The moving mechanism 200 may move the two-fluid nozzle 301 relatively in parallel with the surface of the substrate W while maintaining such an arrangement posture. Thereby, the droplets from the two-fluid nozzle 301 can be supplied to the surface of the substrate W in a predetermined droplet supply state, and the entire surface of the substrate W can be processed uniformly. The configuration and operation of the two-fluid nozzle 301 will be described in detail later.

  A rotary encoder 205 is attached to the motor 204. The rotary encoder 205 outputs information for monitoring the absolute angle θ of the support arm 202 accompanying rotation around the axis 203 to the control unit 150, for example. In addition, since the absolute angle θ of the support arm 202 and the position of the two-fluid nozzle 301 on the substrate W correspond to each other, the absolute angle θ of the support arm 202 is monitored so that the two-fluid nozzle 301 is cleaned during substrate cleaning. The position can be monitored.

  The motor 204 and the rotary encoder 205 described above are supported on a lift base 206. The elevating base 206 is slidably fitted to a guide shaft 207 that faces in the vertical direction, and is screwed to a ball screw 208 that is provided in parallel with the guide shaft 207. The ball screw 208 is linked to the rotation shaft of the lifting motor 209. The amount of rotation of the lifting motor 209 is detected by the rotary encoder 211. When the lifting / lowering motor 209 is driven when the two-fluid nozzle 301 is at the cleaning position above the substrate W, the two-fluid nozzle 301 is lifted and the height of the discharge hole of the two-fluid nozzle 301 from the surface of the substrate W is adjusted. The Thereby, the space | interval of the two-fluid nozzle 301 and the board | substrate W is prescribed | regulated.

  The moving mechanism 200 horizontally moves the two-fluid nozzle 301 with respect to the substrate W by driving the motor 204 in a state where the distance between the two-fluid nozzle 301 and the substrate W is regulated to a predetermined interval (for example, 6 mm) by the lifting motor 209. By moving the two-fluid nozzle 301 on the surface of the substrate W in this way, droplets (a spray-like cleaning liquid) can be supplied in a stable state to each part of the surface of the substrate W, and the surface of the substrate W is excellent. Can be washed.

  The two-fluid nozzle 301 constitutes a two-fluid nozzle in which a pipe 302 for introducing nitrogen gas as a gas and a pipe 311 for supplying pure water as a liquid are connected in communication. The pipe 302 is connected to the nitrogen gas supply unit 303. The pipe 302 includes an electropneumatic regulator 304 that adjusts the pressure of air flowing therethrough to a pressure corresponding to the control signal input from the control unit 150, and a pressure sensor that detects the pressure of air flowing therethrough. 305 and a flow rate sensor 306 for detecting the flow rate of air flowing therethrough are provided. Note that other inert gas or air may be used instead of nitrogen gas.

  The pipe 311 is connected to a pure water supply unit 307 that functions as a supply source of pure water such as DIW (deionized water). The pipe 311 detects the pressure of pure water flowing through the electropneumatic regulator 308 for adjusting the pressure of pure water flowing therethrough to a pressure corresponding to the control signal input from the control unit 150. A pressure sensor 309 and a flow rate sensor 310 for detecting the flow rate of pure water flowing therethrough are disposed. Note that ultrapure water or chemicals may be used instead of pure water.

<Configuration of two-fluid nozzle>
FIG. 3 is a diagram schematically showing the internal structure of the two-fluid nozzle. (A) is a longitudinal sectional view of the two-fluid nozzle, (b) is a sectional view taken along line AA of (a), and (c) is a partially enlarged view of the two-fluid nozzle. It is. The two-fluid nozzle 301 has three types of cylindrical members having different outer diameters, that is, an “outer cylinder 321”, an “intermediate cylinder 322”, and an “inner cylinder 323” in order of increasing outer diameter.

  Among these, the outer cylinder 321 is formed with a through hole in which the inner diameter of the base end (upper end) is larger than that of the distal end (lower end). Thereby, a step portion is formed in the through hole of the outer cylinder 321. An intermediate cylinder 322 is provided with an outer diameter corresponding to the hollow shape of the outer cylinder 321. More specifically, the outer diameter of the base end portion (upper end portion) of the intermediate cylinder 322 is finished to be substantially the same as the inner diameter of the base end portion of the outer cylinder 321, and the distal end portion (lower end portion) of the intermediate cylinder 322 is finished. The outer diameter is finished slightly smaller than the inner diameter of the tip of the outer cylinder 321. Thus, a step portion is formed on the outer surface of the intermediate cylinder 322. Then, the intermediate cylinder 322 is inserted from the base end side of the outer cylinder 321, and the step portion of the intermediate cylinder 322 is positioned by engaging with the step portion formed in the through hole of the outer cylinder 321. The outer cylinder 321 and the intermediate cylinder 322 are fixed to each other on the upper side. When the intermediate cylinder 322 is positioned and fixed with respect to the outer cylinder 321 in this way, an annular gas flow path 331 is formed between the distal end side of the outer cylinder 321 and the distal end portion of the intermediate cylinder 322, and the gas A front end (lower end) of the flow path 331 is an annular gas discharge port 343 that is opened in a slit shape.

  The intermediate cylinder 322 is also provided with a through hole having the same shape as the outer cylinder 321. In other words, the intermediate cylinder 322 is formed with a through hole in which the inner diameter of the base end (upper end) is larger than that of the distal end (lower end). Thereby, a step portion is formed in the through hole of the intermediate cylinder 322. In addition, an inner cylinder 323 is provided with an outer diameter corresponding to the hollow shape of the intermediate cylinder 322. More specifically, the outer diameter of the base end portion (upper end portion) of the inner cylinder 323 is finished to be substantially the same as the inner diameter of the base end portion of the intermediate cylinder 322, and the tip end portion (lower end portion) of the inner cylinder 323 is finished. The outer diameter is finished slightly smaller than the inner diameter of the tip of the intermediate cylinder 322. Thus, a step portion is formed on the outer surface of the inner cylinder 323. Then, the inner cylinder 323 is inserted from the base end side of the intermediate cylinder 322, and the stepped portion of the inner cylinder 323 is positioned by engaging with the stepped portion formed in the through hole of the intermediate cylinder 322. The intermediate cylinder 322 and the inner cylinder 323 are fixed to each other on the upper side. When the inner cylinder 323 is positioned and fixed with respect to the intermediate cylinder 322 in this way, an annular liquid channel 332 is formed between the distal end side of the intermediate cylinder 322 and the distal end portion of the inner cylinder 323, and the liquid The front end (lower end) of the flow path 332 is a liquid discharge port 342 that is annular and has a slit shape.

  The inner cylinder 323 is also provided with a through hole having the same shape as the outer cylinder 321 and the intermediate cylinder 322. That is, the inner cylinder 323 is formed with a through hole in which the inner diameter of the base end (upper end) is larger than that of the distal end (lower end). Accordingly, a step portion is formed in the through hole of the inner cylinder 323. A center shaft 324 is provided with an outer diameter corresponding to the hollow shape of the inner cylinder 323. More specifically, the outer diameter of the base end portion (upper end portion) of the center shaft 324 is finished to be substantially the same as the inner diameter of the base end portion of the inner cylinder 323, and the tip end portion (lower end portion) of the center shaft 324 is finished. The outer diameter is finished slightly smaller than the inner diameter of the tip of the inner cylinder 323. Thus, a step portion is formed on the outer surface of the center shaft 324. The center shaft 324 is inserted from the base end side of the inner cylinder 323, and the stepped portion of the center shaft 324 is engaged and positioned with the stepped portion formed in the through hole of the inner cylinder 323, and the stepped portion The center shaft 324 and the inner cylinder 323 are fixed to each other on the upper side. When the center shaft 324 is positioned and fixed with respect to the inner cylinder 323 in this way, an annular gas flow path 333 is formed between the distal end side of the center shaft 324 and the distal end portion of the inner cylinder 323, and the gas The front end (lower end) of the flow path 333 is an annular gas discharge port 341 that is open in a slit shape.

  A liquid introduction port 352 is provided at the center of the side surface of the intermediate cylinder 322 among these three cylindrical members. The liquid channel 332 is connected to the pure water supply unit 307 through the liquid introduction port 352. Accordingly, when pure water is pumped from the pure water supply unit 307 to the two-fluid nozzle 301, it flows through the liquid flow path 332 via the liquid introduction port 352, and passes from the liquid discharge port 342 to the substrate W held by the support pins 122. It is discharged toward. This discharge direction X corresponds to the “liquid discharge direction” and “droplet supply direction” of the present invention.

  Gas introduction ports 351 and 353 are provided at the center of the side surfaces of the remaining cylindrical members, that is, the outer cylinder 321 and the inner cylinder 323. Gas flow paths 331 and 333 are connected to the nitrogen gas supply unit 303 via gas introduction ports 351 and 353. Therefore, when nitrogen gas is pumped from the nitrogen gas supply unit 303 to the two-fluid nozzle 301, it flows into the gas flow paths 331 and 333 via the gas introduction ports 351 and 353. Then, nitrogen gas is pumped to the gas discharge ports 341 and 343 in parallel with the pure water discharge direction (vertical direction in FIG. 3) X and discharged from the gas discharge ports 341 and 343.

  As described above, in the present embodiment, one annular liquid discharge port 342 and two annular gas discharge ports 341 and 343 are provided, and the arrangement relationship is as follows. That is, as shown in FIG. 3B, the annular gas discharge port 341 is disposed inside the annular liquid discharge port 342, and the annular gas discharge port 343 is disposed outside the annular liquid discharge port 342. In other words, the two annular gas discharge ports 341 and 343 are provided so as to sandwich the annular liquid discharge port 342. Therefore, the gas discharge port 341 corresponds to the “first gas discharge port” of the present invention, and the gas discharge port 343 corresponds to the “second gas discharge port” of the present invention.

  Furthermore, in this embodiment, guide members 361 and 362 are provided in the vicinity of the discharge ports 341, 342, and 343. As shown in FIG. 6C, the guide member 361 has a disk part 361a having an outer diameter slightly smaller than the outer diameter of the inner cylinder 323, and a connecting part 361b is formed upward from the center of the upper surface of the disk part 361a. Projected. The guide member 361 is moved to the center shaft 324 by the bolt 371 in a state where the connecting portion 361b abuts on the tip portion of the center shaft 324 and the upper surface peripheral portion of the disc portion 361a is spaced downward from the tip portion of the inner cylinder 323. It is fixed. For this reason, the peripheral edge of the upper surface of the disk portion 361 a faces the gas discharge port 341 while being orthogonal to the gas flow path 333. Therefore, the nitrogen gas discharged from the gas discharge port 341 is guided in all directions orthogonal to the gas flow path 333 (the entire paper surface in FIG. 3B) and flows into the pure water flow discharged from the liquid discharge port 342. It discharges at right angles to it.

  The other guide member 362 is an annular member having the same outer diameter as the outer cylinder 321, and its inner diameter is slightly wider than the through hole of the intermediate cylinder 322. The upper peripheral edge 362 a of the guide member 362 is finished to have a shape that engages with the tip of the outer cylinder 321. Then, as shown in FIG. 5C, the upper surface outer peripheral edge 362a abuts on the tip of the outer cylinder 321 and the upper inner peripheral edge 362b of the guide member 362 has a gap downward from the tip of the intermediate cylinder 322. In this state, the guide member 362 is fixed to the outer cylinder 321 with a bolt 372. Therefore, the inner peripheral edge 362 b of the upper surface of the guide member 362 faces the gas discharge port 343 while being orthogonal to the gas flow path 33. Therefore, the nitrogen gas discharged from the gas discharge port 343 is guided perpendicularly to the gas flow path 333 and directed in the direction toward the liquid flow of pure water discharged from the liquid discharge port 342, so that Dispense at a right angle. In this embodiment, the guide members 361 and 362 are attached to the center shaft 324 and the outer cylinder 321 by bolts 371 and 372, but the attachment method and the attachment manner are not limited to this. For example, the guide member 362 and the outer cylinder 321 may be integrally formed.

  Thus, nitrogen gas is discharged with respect to the liquid flow of pure water, and droplets of pure water are formed by the collision of pure water and nitrogen gas. Then, droplets are supplied toward the substrate W from the annular gap 381 between the guide members 361 and 362.

  As described above, according to this embodiment, pure water is ejected in a predetermined droplet supply direction, and two different paths so as to sandwich the pure water, that is, a one-dot chain line in FIG. Nitrogen gas is discharged through the two gas discharge paths shown in FIG. 5 and pure water droplets are formed by collision of pure water and nitrogen gas. Thus, nitrogen gas is discharged into the liquid flow of pure water so as to be sandwiched between two different paths, and a shearing force acts on the pure water. In addition, in this embodiment, since the nitrogen gas is discharged at right angles to the liquid flow of pure water in any of the two gas discharge paths, the shear force is further increased. As a result, fine droplets are formed, and the substrate W is cleaned by the droplets, so that the substrate W can be satisfactorily cleaned with an excellent removal rate without damaging the substrate W. it can.

  Further, since nitrogen gas is discharged at right angles to the liquid flow of pure water, droplet formation is performed in the immediate vicinity of the liquid discharge port 342. The droplets thus formed can be immediately supplied to the substrate W. Therefore, the distance between the two-fluid nozzle and the substrate W can be reduced, and damage to the substrate W can be significantly suppressed.

  In this embodiment, the intermediate cylinder 322 and the inner cylinder 323 constitute a “liquid ejection unit” that ejects pure water from the liquid ejection port 342 in the droplet supply direction X. Further, the “first gas discharge unit” of the present invention is provided inside the liquid discharge port 342. In this embodiment, the inner cylinder 323, the center shaft 324, and the guide member 361 constitute a first gas discharge portion, and the guide member 361 corresponds to the “first guide member” of the present invention. Furthermore, the “second gas discharge portion” of the present invention is provided outside the liquid discharge port 342. In this embodiment, the outer cylinder 321, the inner cylinder 323, and the guide member 362 constitute a second gas discharge portion, and the guide member 362 corresponds to the “second guide member” of the present invention.

  Here, in order to verify the effect of atomizing the droplets according to the above embodiment, the following experiment was performed. That is, as the two-fluid nozzle 301 according to the above embodiment, the opening width (slit width) of the liquid discharge port 342 is set to 0.1 mm, while the opening widths (slit width) of the gas discharge ports 341 and 343 are set to 0.3 mm. We prepared what was set to. As a comparative example, a two-fluid nozzle having the same configuration as that of the embodiment was prepared except that the discharge angle α (see FIG. 4) of nitrogen gas into pure water (liquid) was 30 °. Then, as shown in Table 1, while variously setting the flow rate of nitrogen gas (gas flow rate) and the flow rate of pure water (liquid flow rate), the droplet average speed, the Sauter average diameter, the arithmetic average diameter under each setting condition Was measured using a SizingMaster manufactured by Lavision. The results are summarized in the same table. Further, the relationship between the average droplet velocity and the average Sauter diameter is plotted on a graph (see FIG. 4).

  As is apparent from the table and FIG. 4, the droplets can be atomized by setting the orthogonal to the liquid flow, that is, by setting the discharge angle α to 90 °. Further, even if the liquid flow rate and the gas flow rate are set so that the average droplet speed becomes relatively slow by orthogonal ejection, the droplets can be sufficiently atomized. In this way, suppressing the average droplet speed is suitable for suppressing damage to the substrate W, and has an excellent effect that the particle removal rate can be increased by atomizing droplets while achieving damage suppression. An effect is obtained.

  It has been verified that such an effect can be obtained even when the discharge angle α is changed to about 80 °. In the present application, “perpendicular to the liquid flow of liquid” means that the discharge angle α is 80 ° to It means the range of 90 °.

The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, nitrogen gas is discharged at a right angle to the liquid flow of pure water in either of the two gas discharge paths, but it may be configured to discharge at a right angle in only one of them. Good. For example, as shown in FIG. 5, the first and second gas discharge portions are provided so as to sandwich the liquid discharge port 342, but only the second gas discharge portion provided outside the liquid discharge port 342 is the liquid discharge port 342. Nitrogen gas is discharged at right angles to the liquid flow of pure water discharged from the nozzle. Conversely, in the embodiment shown in FIG. 6, only the first gas discharge portion provided inside the liquid discharge port 342 discharges nitrogen gas at a right angle with respect to the liquid flow of pure water discharged from the liquid discharge port 342. I am letting. Also in the two-fluid nozzle 301 adopting these configurations, the same effects as those of the above-described embodiment can be obtained.

  Moreover, in the said embodiment, the gas flow path 331 of a 1st gas discharge part and the gas flow path 333 of a 2nd gas discharge part are connected to the piping 302, and it is comprised so that the nitrogen gas of the same flow volume may be supplied. However, it may be configured to supply nitrogen gas at different flow rates. In this case, the supply characteristics of the droplets supplied from the gap 381 (for example, how the droplets spread and the average droplet velocity) can be adjusted by controlling the nitrogen gas supplied to each gas discharge unit.

  In the above embodiment, pure water is discharged from one liquid discharge port 342, but the liquid discharge unit may be configured to have a plurality of liquid discharge ports. As a result, the liquid is separated into a plurality of liquids when discharged from the liquid discharge port, which is suitable for atomizing the droplets.

  In the above embodiment, the present invention is applied to a substrate processing apparatus that cleans a substrate with pure water. However, a substrate processing apparatus that performs predetermined substrate processing by supplying droplets to a substrate using a two-fluid nozzle. The present invention can be generally applied. Furthermore, the two-fluid nozzle and the droplet supply method according to the present invention are preferably applied to the substrate processing apparatus as described above, but the application target is not limited to this, and the liquid is gas. The present invention can be applied to a two-fluid nozzle that supplies liquid droplets formed by colliding with each other in a predetermined direction and a droplet supply method in general.

  The present invention can be applied to a droplet supply method and a two-fluid nozzle that supplies droplets by forming a droplet of liquid by colliding the liquid and gas and supplying the droplet. Further, the present invention can be applied to a substrate processing apparatus that supplies a liquid droplet to a substrate using a droplet supply method or a two-fluid nozzle to perform a predetermined substrate processing.

1 is a plan layout view showing a substrate processing system equipped with an embodiment of a substrate processing apparatus according to the present invention. It is a side surface schematic diagram showing one embodiment of a substrate processing device concerning this invention. It is a figure which shows typically the internal structure of a two-fluid nozzle. It is a graph which shows the effect by the two fluid nozzle of FIG. It is a figure which shows other embodiment of the two-fluid nozzle concerning this invention. It is a figure which shows another embodiment of the two-fluid nozzle concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Substrate processing apparatus 122 ... Support pin (substrate holding means)
301 ... Two-fluid nozzle 321 ... Outer cylinder 322 ... Intermediate cylinder 323 ... Inner cylinder 324 ... Center shaft 331 ... First gas channel 332 ... Liquid channel 333 ... Second gas channel 341 ... First gas outlet 342 ... Liquid Discharge port 343 ... 2nd gas discharge port 361 ... 1st guide member 362 ... 2nd guide member W ... Substrate X ... Discharge direction (droplet discharge direction, droplet supply direction) of pure water

Claims (14)

Substrate holding means for holding the substrate;
A two-fluid nozzle for supplying droplets to the substrate held by the substrate holding means,
The two-fluid nozzle is
A liquid ejection unit that ejects liquid from a liquid ejection port toward the substrate;
A first and a second gas discharge unit that are provided so as to sandwich the liquid discharge port and form a liquid droplet by colliding a gas with the liquid discharged from the liquid discharge port;
At least one of the first and second gas discharge units discharges the gas at right angles to the liquid flow of the liquid discharged from the liquid discharge port.   The substrate processing apparatus according to claim 1, wherein both the first and second gas discharge units discharge the gas at a right angle to the liquid flow of the liquid discharged from the liquid discharge port. The first gas discharge unit has a first gas discharge port for discharging the gas, and the second gas discharge unit has a second gas discharge port for discharging the gas,
The shapes of the first and second gas discharge ports and the liquid discharge port as viewed from the substrate side held by the substrate holding means are annular,
3. The substrate processing apparatus according to claim 1, wherein the first gas discharge port is provided inside the annular liquid discharge port, and the second gas discharge port is provided outside the annular liquid discharge port.   The first gas discharge part is orthogonal to the first gas flow path, and a first gas flow path for guiding gas to the first gas discharge opening in parallel with the liquid discharge direction from the liquid discharge opening. And a first guide member that is provided opposite to the first gas discharge port and guides the gas discharged from the first gas discharge port in all directions orthogonal to the first gas flow path. The substrate processing apparatus as described.   The second gas discharge unit guides the gas to the liquid flow while changing the flow of the gas discharged from the second gas discharge port in a direction orthogonal to the liquid flow of the liquid. The substrate processing apparatus of Claim 3 or 4 which has these.   The substrate processing apparatus according to claim 1, wherein the liquid discharge unit includes a plurality of the liquid discharge ports. In a two-fluid nozzle that supplies droplets,
A liquid ejection unit that ejects liquid from the liquid ejection port in the droplet supply direction;
A first and a second gas discharge unit provided so as to sandwich the liquid discharge port, and forming a droplet by causing a gas to collide with the liquid discharged from the liquid discharge port;
At least one of the first and second gas discharge portions discharges the gas at a right angle to the liquid flow of the liquid discharged from the liquid discharge port.   The two-fluid nozzle according to claim 7, wherein both the first and second gas discharge units discharge the gas at a right angle to the liquid flow of the liquid discharged from the liquid discharge port. The first gas discharge unit has a first gas discharge port for discharging the gas, and the second gas discharge unit has a second gas discharge port for discharging the gas,
The shape of the first and second gas discharge ports and the liquid discharge port as viewed from the downstream side in the droplet supply direction is annular,
The two-fluid nozzle according to claim 7 or 8, wherein the first gas discharge port is provided inside the annular liquid discharge port, and the second gas discharge port is provided outside the annular liquid discharge port.   The first gas discharge unit includes a first gas channel that guides gas to the first gas discharge port in parallel with the droplet supply direction, and the first gas discharge unit that is orthogonal to the first gas channel. The two-fluid nozzle according to claim 9, further comprising: a first guide member that is provided to face the outlet and guides the gas discharged from the first gas discharge port in all directions orthogonal to the first gas flow path.   The second gas discharge unit guides the gas to the liquid flow while changing the flow of the gas discharged from the second gas discharge port in a direction orthogonal to the liquid flow of the liquid. The two-fluid nozzle according to claim 9 or 10, comprising:   The two-fluid nozzle according to any one of claims 7 to 11, wherein the liquid discharge section includes a plurality of the liquid discharge ports. A droplet supply method for supplying a droplet of the liquid formed by colliding a gas with a liquid in a predetermined direction,
A first step of discharging the liquid in a droplet supply direction;
A second step of forming droplets of the liquid by discharging the gas so as to sandwich the liquid discharged in two different gas discharge paths and in the droplet supply direction;
In the second step, at least one of the two gas discharge paths discharges gas at right angles to the liquid flow of the liquid. Before the first and second steps, a third step of providing a substrate on the downstream side in the droplet supply direction,
The droplet supply method according to claim 13, wherein in the first step, a processing liquid for cleaning the substrate is discharged as the liquid.

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