JP5031542B2 - Two-fluid nozzle, substrate cleaning apparatus and substrate cleaning method - Google Patents

Description

  The present invention relates to a two-fluid nozzle that sprays droplets of a cleaning liquid, a substrate processing apparatus including the two-fluid nozzle, and a substrate cleaning method, and in particular, can improve the cleaning effect on a substrate to be processed, and the cleaning liquid The present invention relates to a two-fluid nozzle, a substrate processing apparatus, and a substrate cleaning method that can reduce damage to a substrate to be processed when spraying liquid droplets.

  In a semiconductor device manufacturing process, when a film forming process or an etching process is performed on a semiconductor wafer (hereinafter, also simply referred to as a wafer), particles may adhere to the wafer. Therefore, it is necessary to perform a wafer cleaning process.

  As a substrate cleaning apparatus that performs a cleaning process on a wafer, for example, while rotating the wafer on a spin chuck, the wafer is cleaned by supplying a cleaning liquid composed of pure water or a chemical liquid from a nozzle or the like to the surface, and thereafter It is known that the wafer is rinsed as necessary, and finally dried by rotating the wafer at a high speed.

  Here, a two-fluid nozzle may be used as a nozzle for supplying the cleaning liquid to the wafer (see, for example, Patent Document 1). The two-fluid nozzle generally refers to a nozzle of a type in which minute droplets are generated by mixing gas and liquid inside, and the minute droplets are sprayed. The two-fluid nozzle is supplied with cleaning liquids such as pure water and chemicals and gas for generating droplets such as nitrogen gas from different paths, and the droplet generating gas and the cleaning liquid are mixed inside the two-fluid nozzle. A droplet of cleaning liquid is generated, and the droplet of cleaning liquid is sprayed on a portion of the wafer. Further, the two-fluid nozzle moves in the horizontal direction along the surface of the wafer with a slight distance from the surface. When the two-fluid nozzle moves along the surface of the wafer while the wafer is rotating, droplets of the cleaning liquid are sprayed uniformly from the two-fluid nozzle onto the surface of the wafer, and a liquid film of the cleaning liquid is applied to the surface of the wafer. Will be generated.

  Details of the configuration of a general straight pipe type two-fluid nozzle will be specifically described with reference to FIGS. FIG. 7 is a longitudinal sectional view showing details of the configuration of a conventional two-fluid nozzle. FIG. 8A is a diagram showing an outline of the discharge port of a conventional two-fluid nozzle as shown in FIG. 7, and FIG. 8B is a diagram showing the position at the nozzle discharge port and the droplets of the cleaning liquid. It is a graph which shows the relationship with a particle diameter.

  As shown in FIG. 7, the two-fluid nozzle 80 is supplied with a cleaning liquid such as pure water or a chemical liquid from a cleaning liquid supply pipe 86 and nitrogen gas is supplied from a nitrogen gas supply pipe 88. The two-fluid nozzle 80 has a nozzle main body 80 a, and inside this nozzle main body 80 a, a cleaning liquid flow path 80 b that communicates with the cleaning liquid supply pipe 86 and a nitrogen gas that communicates with the nitrogen gas supply pipe 88. Each channel 80c is provided. The cleaning liquid flow path 80b and the nitrogen gas flow path 80c join at a trifurcated joining portion 80d inside the nozzle body 80a, and an internal passage is further formed from the joining portion 80d to the discharge port 80e of the two-fluid nozzle 80. ing. The cross-sectional shape of the discharge port 80e of the two-fluid nozzle 80 is substantially circular.

  In such a general straight pipe type two-fluid nozzle 80, the cleaning liquid sent from the cleaning liquid supply pipe 86 to the cleaning liquid flow path 80b and the nitrogen gas supply pipe 88 to the nitrogen gas flow path 80c in the nozzle body 80a. Nitrogen gas sent to is collided at the junction 80d and mixed, whereby droplets of the cleaning liquid are formed at the junction 80d. The droplets of the cleaning liquid are sprayed from the discharge port 80e onto the wafer W. It has come to be. In FIG. 7, a region indicated by a two-dot chain line indicates a spray range of droplets of the cleaning liquid sprayed from the two-fluid nozzle 80 toward the wafer W.

  Next, the particle size of the droplets of the cleaning liquid sprayed from the discharge port 80e of the two-fluid nozzle 80 will be described as a general tendency with reference to FIG. Here, depending on the position of the two-fluid nozzle 80 at the discharge port 80e, the particle diameter of the droplets of the cleaning liquid sprayed from the discharge port 80e is different. As shown in FIG. 8A, assuming that the center of the discharge port 80e having a substantially circular cross section is the coordinate 0, and both ends of the discharge port 80e are the coordinate -a and the coordinate a, respectively, as shown in FIG. In addition, the particle diameter of the liquid droplets of the cleaning liquid gradually decreases from the end (coordinate -a, coordinate a) of the discharge port 80e toward the center (coordinate 0). That is, the particle diameter of the cleaning liquid droplet sprayed from the vicinity of the end of the discharge port 80e of the two-fluid nozzle 80 is larger than the particle diameter of the cleaning liquid droplet sprayed from the center of the discharge port 80e. Yes.

JP 2005-251847 A

  In general, droplets having a large particle size of the cleaning liquid sprayed from the straight pipe onto the wafer W are distributed more as they approach the pipe end face. When the particle diameter of the droplet of the cleaning liquid sprayed on the wafer W is large, the frequency of the cleaning liquid droplet colliding with the wafer W is smaller than that when the particle diameter is small, and the cleaning effect is deteriorated. Further, when such a droplet of cleaning liquid having a large particle size collides with the wafer W, the wafer W may be seriously damaged. As described above, there is a demand to make a droplet having a large particle diameter sprayed from the vicinity of the end of the discharge port 80e of the two-fluid nozzle 80 small.

  The present invention has been made in consideration of such points, and the droplets of the cleaning liquid sprayed on the substrate to be processed are made to have a small droplet diameter as a whole from the discharge port. Therefore, it is possible to improve the cleaning effect on the substrate to be processed, and to reduce damage to the substrate to be processed when spraying the liquid droplets of the cleaning liquid, the substrate cleaning apparatus, and the substrate cleaning It aims to provide a method.

The two-fluid nozzle of the present invention is supplied with a cleaning liquid and a droplet generating gas from the outside, and the cleaning liquid and the droplet generating gas are mixed inside to generate a cleaning liquid droplet inside. A flow path that is provided inside the main body and flows a droplet of the cleaning liquid generated by mixing the cleaning liquid and the liquid droplet generating gas, and a flow path at least partially curved in the main body A discharge port provided at the downstream end of the flow path and sprayed to the outside with droplets of the cleaning liquid sent from the flow path, and provided on the radially outer side of the curved portion of the flow path, And a discharge port for discharging a droplet of the cleaning liquid flowing outside in the radial direction from the flow path. The curved portion of the flow path has a spiral shape.

  In such a two-fluid nozzle, a cleaning liquid droplet having a large particle size among the cleaning liquid droplets of various particle sizes is formed in a curved portion of the flow path provided inside the main body of the two-fluid nozzle. Since a larger centrifugal force acts on the liquid droplets of the cleaning liquid having a smaller particle diameter, the liquid droplets of the cleaning liquid having a larger particle diameter flow outside in the radial direction at the curved portion. A discharge port is provided on the radially outer side of the curved portion of the flow path, and the liquid droplets of the cleaning liquid flowing on the radially outer side of the curved portion are discharged from the flow channel through the discharge port. Therefore, the liquid droplets of the cleaning liquid having a large particle diameter are discharged from the flow path through the discharge port. For this reason, the droplets of the cleaning liquid sent to the discharge port without being discharged by the discharge port in the flow path have a small particle diameter. In this way, the droplets of the cleaning liquid sprayed from the entire discharge port onto the substrate to be processed can have a small particle diameter.

Further, since the curved portion of the flow path has a spiral shape, the distance of the curved portion of the flow path can be increased, so that the time during which the centrifugal force acts on the liquid droplets of the cleaning liquid is increased. Therefore, in the curved portion of the flow path, the cleaning liquid droplet having a large particle size is further separated from the cleaning liquid droplet having a small particle size. The droplet of the cleaning liquid having a large diameter flows more reliably on the radially outer side in the curved portion.

  In the two-fluid nozzle of the present invention, the discharge port is provided with a suction mechanism, and the suction mechanism sucks the liquid droplets of the cleaning liquid that flows radially outside the curved portion of the flow path. It is preferable that droplets of the cleaning liquid are discharged from the flow path through the discharge port. Thus, the droplets of the cleaning liquid flowing on the radially outer side in the curved portion of the flow path can be more reliably discharged from the flow path through the discharge port by suction by the suction mechanism.

  A substrate cleaning apparatus according to the present invention includes the above-described two-fluid nozzle, and cleans the substrate to be processed with a droplet of cleaning liquid sprayed from a discharge port of the two-fluid nozzle.

In the substrate cleaning method of the present invention, a cleaning liquid and a droplet generating gas are mixed inside a two-fluid nozzle to generate a cleaning liquid droplet, and the cleaning liquid droplet is generated from the two-fluid nozzle on the substrate to be processed. A substrate cleaning method for cleaning a substrate to be processed by spraying, wherein a cleaning liquid and a droplet generating gas are respectively supplied to a two-fluid nozzle, and the cleaning liquid and the droplet generating gas are supplied to the two-fluid nozzle. A step of generating a droplet of the cleaning liquid by mixing inside, and a droplet of the cleaning liquid flowing in the flow path at least partially curved, and at this time, the liquid droplet of the cleaning liquid flowing on the radially outer side in the curved portion of the flow path the includes a step of discharging from the flow channel through the outlet, a step of spraying the substrate to be processed from the discharge port of the two-fluid nozzle droplets of the cleaning liquid that has not been discharged in the flow path, wherein the flow Curved part of the road Wherein the has a helical shape.

  According to such a substrate cleaning method, in the curved portion of the flow path provided inside the two-fluid nozzle, out of the cleaning liquid droplets having various particle diameters, the cleaning liquid droplets having a large particle diameter include particles. Since a centrifugal force is larger than that of a cleaning liquid droplet having a small diameter, the cleaning liquid droplet having a large particle diameter flows outside in the radial direction at the curved portion. Then, since the cleaning liquid droplets flowing radially outside the curved portion are discharged from the flow path through the discharge port, the cleaning liquid droplets having a large particle diameter are flowed through the discharge port. Discharged from. For this reason, the droplets of the cleaning liquid sent to the discharge port without being discharged by the discharge port in the flow path have a small particle diameter. In this manner, the droplets of the cleaning liquid sprayed from the discharge port onto the substrate to be processed can have a small particle diameter.

  In the substrate cleaning method of the present invention, it is preferable that the cleaning liquid droplets are discharged from the flow path by sucking the cleaning liquid droplets flowing outside in the radial direction at the curved portion of the flow path from the outside. Thereby, the droplets of the cleaning liquid flowing on the radially outer side in the curved portion of the flow path can be more reliably discharged from the flow path through the discharge port by suction from the outside.

  According to the two-fluid nozzle, the substrate cleaning apparatus, and the substrate cleaning method of the present invention, it is possible to improve the cleaning effect on the substrate to be processed and reduce damage to the substrate to be processed when spraying the liquid droplets of the cleaning liquid. Can do.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 4 are views showing an embodiment of a substrate cleaning apparatus having a two-fluid nozzle according to the present invention.
Among these, FIG. 1 is a schematic configuration diagram showing the configuration of the substrate cleaning apparatus according to one embodiment of the present invention, and FIG. 2 shows the details of the configuration of the two-fluid nozzle in the substrate cleaning apparatus shown in FIG. FIG. 3 is a longitudinal sectional view, and FIG. 3 is a transverse sectional view of the two-fluid nozzle shown in FIG. FIG. 4 is an explanatory view schematically showing the flow of cleaning liquid droplets in the two-fluid nozzle shown in FIGS.

  First, the overall configuration of the substrate cleaning apparatus 1 will be described with reference to FIG. The substrate cleaning apparatus 1 is for cleaning a semiconductor wafer (hereinafter also simply referred to as a wafer) W as a substrate to be processed.

  The substrate cleaning apparatus 1 includes a chamber 10 and a spin chuck 12 installed in the chamber 10 for holding a wafer W. Further, in the chamber 10, an outer cylinder 16 provided so as to cover the wafer W held by the spin chuck 12, a two-fluid nozzle 20 for spraying droplets of cleaning liquid onto the wafer W held by the spin chuck 12, and Is provided. Hereinafter, details of each component of the substrate cleaning apparatus 1 will be described.

  The spin chuck 12 rotates while holding the wafer W substantially horizontally. Specifically, the spin chuck 12 is arranged so as to extend in the vertical direction, and a disk attached to the upper end of the spin shaft. A spin base. When the wafer W is held by the spin chuck 12, the wafer W is placed on the upper surface of the spin base. A spin chuck drive mechanism (not shown) such as a motor is attached to the rotary shaft portion, and the spin chuck drive mechanism can rotate the rotary shaft portion around its central axis. Thus, the wafer W held on the spin chuck 12 can be rotated on a horizontal plane. Further, the spin chuck 12 can be reciprocated in the vertical direction by a spin chuck lifting / lowering mechanism (not shown). Thus, when the wafer W is carried into the chamber 10 and held by the spin chuck 12 or when the wafer W on the spin chuck 12 is carried out of the chamber 10, the upper end of the spin chuck 12 is placed on the outer cylinder 16. It can be higher than the upper end. On the other hand, when supplying the cleaning liquid from the two-fluid nozzle 20 to the wafer W held on the spin chuck 12, the side wall of the outer cylinder 16 is positioned on the side of the wafer W held on the spin chuck 12. Can do.

  In the chamber 10, a substantially cylindrical outer cylinder 16 is provided so as to surround the side of the spin chuck 12. The central axis of the outer cylinder 16 substantially coincides with the central axis of the rotation shaft portion of the spin chuck 12, and the outer cylinder 16 is provided with a bottom plate at the lower end and opened at the upper end.

  One end of a cleaning liquid discharge pipe 50 is connected to the bottom plate of the outer cylinder 16. Here, the cleaning liquid used for cleaning the wafer W and sent to the bottom plate of the outer cylinder 16 is discharged through the cleaning liquid discharge pipe 50.

  A two-fluid nozzle 20 is provided downward in a position above the wafer W when held by the spin chuck 12 in the chamber 10. The two-fluid nozzle 20 is connected to the rotary shaft portion 24 via the arm 22. The rotary shaft portion 24 is provided with an arm drive mechanism (not shown) that rotates the rotary shaft portion 24 in both forward and reverse directions. The arm driving mechanism rotates the arm 22 in the horizontal direction around the rotating shaft 24, thereby moving the two-fluid nozzle 20 from a position above the center of the wafer W to a position outside the peripheral edge of the wafer W. The reciprocation is made along the horizontal plane within the range up to. Further, the arm drive mechanism can reciprocate the rotary shaft portion 24 in the vertical direction. As a result, the distance between the tip of the two-fluid nozzle 20 and the wafer W held by the spin chuck 12 can be adjusted.

  The configuration of the two-fluid nozzle 20 will be specifically described with reference to FIGS. As described above, the two-fluid nozzle generally refers to a nozzle that generates fine droplets by mixing a gas and a liquid and sprays the fine droplets. In the present embodiment, the two-fluid nozzle 20 is supplied with a cleaning liquid made of pure water or a chemical solution from a cleaning liquid supply pipe 26 (described later), and is supplied with nitrogen gas from a nitrogen gas supply pipe 28 (described later). It is like that. The two-fluid nozzle 20 is provided, for example, in a substantially cylindrical nozzle upper body 20a made of, for example, a fluororesin, and in contact with the lower portion of the nozzle upper body 20a. For example, the substantially cylindrical nozzle lower body made of a fluororesin 20e and a substantially cylindrical nozzle inner body 20f provided to fit in a hollow portion of the nozzle lower body 20e. The nozzle upper body 20a, the nozzle lower body 20e, and the nozzle inner body 20f constitute a body portion of the two-fluid nozzle 20.

  Inside the upper nozzle body 20a of the two-fluid nozzle 20, a cleaning liquid flow path 20b that communicates with the cleaning liquid supply pipe 26 and a nitrogen gas flow path 20c that communicates with the nitrogen gas supply pipe 28 are provided. Yes. The cleaning liquid flow path 20b and the nitrogen gas flow path 20c are joined at a joining portion 20d inside the nozzle upper body 20a. In the merging section 20d, the cleaning liquid sent from the cleaning liquid supply pipe 26 via the cleaning liquid flow path 20b and the nitrogen gas sent from the nitrogen gas supply pipe 28 via the nitrogen gas flow path 20c collide and mix. Thus, droplets of the cleaning liquid are generated in the merging portion 20d.

  As described above, the substantially cylindrical nozzle inner body 20f is provided to fit in the hollow portion of the substantially cylindrical nozzle lower body 20e. The nozzle inner body 20f is provided with a spiral flow path 20h. The upstream end of the spiral channel 20h communicates with the merging portion 20d of the nozzle upper body 20a, while a discharge port 20j is provided at the downstream end of the spiral channel 20h. That is, the cleaning liquid droplets generated in the merging portion 20d are sent to the discharge port 20j through the spiral flow path 20h in the nozzle inner body 20f, and the cleaning liquid droplets are transferred from the discharge port 20j to the wafer W. It comes to be sprayed.

  Further, as shown in FIG. 2, a discharge flow path 20g is formed inside the substantially cylindrical nozzle lower body 20e so that the cleaning liquid droplets discharged from the spiral flow path 20h are sent. ing. The discharge flow path 20g and the spiral flow path 20h communicate with each other through a through hole 20i formed so as to penetrate the inner wall of the nozzle lower body 20e. As shown in FIG. 3, the end portion of the through hole 20i communicates with a radially outer portion of the spiral flow path 20h. Here, the radially outer portion in the flow path 20h refers to a portion farthest from the spiral center O (see FIG. 3) in the flow path 20h.

  FIG. 4 schematically shows the flow of the cleaning liquid droplets in the nozzle inner body 20 f of the two-fluid nozzle 20. As shown in FIG. 4, in the nozzle inner body 20f of the two-fluid nozzle 20, the cleaning liquid droplets sent from the merging portion 20d flow through the spiral flow path 20h, and finally downward from the discharge port 20j. Of the cleaning liquid droplets flowing through the spiral flow path 20h, some of the cleaning liquid droplets are discharged from the flow path 20h through the through holes 20i. The discharged droplets of the cleaning liquid are sent to the discharge flow path 20g inside the nozzle lower body 20e.

  Here, the flow path 20h has a spiral shape, and the through hole 20i communicates with a radially outer portion of the flow path 20h. For this reason, out of the cleaning liquid droplets of various particle sizes flowing through the flow path 20h, the cleaning liquid droplets having a large particle size have a larger centrifugal force than the droplets of the cleaning liquid having a small particle size, so Large cleaning liquid droplets flow radially outward in the flow path 20h. As a result, a droplet of cleaning liquid having a large particle diameter is sent to the through hole 20i.

  As shown in FIG. 1, a suction device 40 is connected to the two-fluid nozzle 20 via a suction pipe 42. The suction device 40 sucks liquid droplets of the cleaning liquid from the inside of the two-fluid nozzle 20 through the suction pipe 42. More specifically, the suction pipe 42 communicates with the discharge flow path 20g inside the nozzle lower body 20e through a through hole 20k formed so as to penetrate the outer wall of the nozzle lower body 20e. That is, the droplet of the cleaning liquid sent from the spiral flow path 20h to the through hole 20i is sent to the suction pipe 42 via the discharge flow path 20g and the through hole 20k, and finally sent to the suction device 40. It is supposed to be. The flow of the cleaning liquid droplet is promoted by suction by the suction device 40.

  As shown in FIG. 1, a cleaning liquid tank 30 is provided at the upstream end of the cleaning liquid supply pipe 26, and cleaning liquid made of pure water or chemical liquid is stored in the cleaning liquid tank 30. The cleaning liquid is sent from the cleaning liquid tank 30 to the cleaning liquid supply pipe 26 by a pumping means (not shown) such as a pump. Further, the cleaning liquid supply pipe 26 is provided with a valve 34 whose opening degree can be adjusted, and a filter 38 for particle removal.

  A nitrogen gas supply pipe 28 is connected to the two-fluid nozzle 20, and a nitrogen gas supply mechanism 32 is provided at the upstream end of the nitrogen gas supply pipe 28. The nitrogen gas supply mechanism 32 can supply high-pressure nitrogen gas to the nitrogen gas supply pipe 28. The nitrogen gas supply pipe 28 is provided with a valve 36. By changing the opening degree of the valve 36 and changing the pressure (flow rate) of nitrogen gas sent to the two-fluid nozzle 20, the particle diameter of the droplets of the cleaning liquid generated in the two-fluid nozzle 20 can be changed. As a result, the cleaning performance of the wafer W by the droplets of the cleaning liquid can be changed.

  Next, the operation of the substrate cleaning apparatus 1 having such a configuration will be described.

  First, the wafer W is loaded into the chamber 10 while the spin chuck 12 is moved upward by the spin chuck lifting mechanism, and the wafer W is held by the spin chuck 12. Then, the spin chuck 12 is lowered so that the side wall of the outer cylinder 16 is positioned on the side of the spin chuck 12.

  Next, a cleaning liquid is supplied to the wafer W held and rotated by the spin chuck 12 in the chamber 10. Specifically, the valves 34 and 36 are opened, and cleaning liquid and nitrogen gas are simultaneously supplied to the two-fluid nozzle 20, and droplets of the cleaning liquid are supplied from the two-fluid nozzle 20 to the wafer W on the rotating spin chuck 12. Try to spray.

  The operation in the two-fluid nozzle 20 from when the cleaning liquid and nitrogen gas are sent until the droplets of the cleaning liquid are sprayed on the wafer W will be described. First, in the junction 20d inside the nozzle upper body 20a of the two-fluid nozzle 20, the cleaning liquid sent from the cleaning liquid supply pipe 26 via the cleaning liquid flow path 20b and the nitrogen gas supply pipe 28 via the nitrogen gas flow path 20c. The sent nitrogen gas collides and mixes, and thereby, droplets of the cleaning liquid are generated in the merging portion 20d. The droplet of the cleaning liquid generated in this way flows through the spiral flow path 20h inside the nozzle inner body 20f, and is finally sent to the discharge port 20j. Then, the droplet of the cleaning liquid is sprayed toward the wafer W from the ejection port 20j.

  On the other hand, of the cleaning liquid droplets flowing through the spiral flow path 20h, the cleaning liquid droplets having a large diameter are discharged from the flow path 20h through the through holes 20i. The discharged droplets of the cleaning liquid having a large diameter are sent to the discharge flow path 20g inside the nozzle lower body 20e.

  Here, while the two-fluid nozzle 20 is spraying droplets of the cleaning liquid onto the wafer W, the suction device 40 is operated, and the suction device 40 is disposed in the two-fluid nozzle 20 via the suction pipe 42. Liquid droplets of the cleaning liquid are sucked from the discharge channel 20g. As a result, the droplet of the cleaning liquid having a large diameter discharged from the spiral flow path 20 h is sucked by the suction device 40 through the discharge flow path 20 g and the suction pipe 42.

  While the two-fluid nozzle 20 is spraying the cleaning liquid droplets on the wafer W, the arm 22 is rotated in the horizontal direction about the rotation shaft portion 24 by the arm driving mechanism. Then, the arm 22 moves in the horizontal direction from the approximate center of the wafer W toward the peripheral edge above the wafer W, and the two-fluid nozzle 20 attached to the arm 22 moves in the horizontal direction. . In this way, by moving the arm 22 in the horizontal direction above the wafer W by the arm driving mechanism, the two-fluid nozzle 20 attached to the arm 22 is evenly and uniformly applied to the upper surface of the wafer W. As a result, the liquid film of the cleaning liquid is formed on the upper surface of the wafer W.

  Thereafter, the two-fluid nozzle 20 moves to the outside of the wafer W, the spraying of the cleaning liquid from the two-fluid nozzle 20 is stopped, and the spin chuck driving mechanism rotates the spin chuck 12 at a high speed. As a result, the wafer W held on the spin chuck 12 is also rotated at high speed, and the wafer W is dried. In this way, a series of operations in the substrate cleaning apparatus 1 is completed.

  As described above, according to the two-fluid nozzle 20 according to the present embodiment, among the droplets of the cleaning liquid having various particle diameters in the spiral flow path 20h provided in the nozzle inner body 20f, Since a large cleaning liquid droplet has a larger centrifugal force than that of a cleaning liquid droplet having a small particle diameter, the cleaning liquid droplet having a large particle diameter flows on the outer side in the radial direction of the spiral flow path 20h. A through hole 20i is provided on the outer side in the radial direction of the spiral flow path 20h, and a droplet of the cleaning liquid flowing on the outer side in the radial direction of the flow path 20h is discharged from the flow path 20h through the through hole 20i. Thus, a droplet of cleaning liquid having a large particle diameter is discharged from the flow path 20h through the through hole 20i. For this reason, the droplet of the cleaning liquid that is not discharged through the through hole 20i in the flow path 20h and is sent to the discharge port 20j has a small particle diameter. In this way, the droplets sprayed from the vicinity of the end of the discharge port 20j of the two-fluid nozzle 20 can also have a small particle diameter. For this reason, the cleaning liquid sprayed onto the wafer W from the discharge port 20j. The droplets can have a small particle size as a whole.

  In addition, since the flow path 20h on the downstream side of the merging portion 20d has a spiral shape, the distance of the curved portion in the flow path 20h can be increased. This increases the time during which the centrifugal force acts on the droplets of the cleaning liquid. For this reason, in this flow path 20h, the cleaning liquid droplets having a large particle size are further separated from the cleaning liquid droplets having a small particle diameter. Large droplets of cleaning liquid flow more reliably on the radially outer side of the flow path 20h.

  The discharge channel 20g is provided with a suction device 40 via a suction tube 42 so that the suction device 40 sucks the droplets of the cleaning liquid flowing on the outer side in the radial direction of the spiral flow channel 20h. It has become. For this reason, the liquid droplets of the cleaning liquid flowing on the radially outer side of the flow path 20h can be more reliably discharged from the flow path 20h through the through-hole 20i and the discharge flow path 20g by suction by the suction device 40. .

  The two-fluid nozzle, the substrate cleaning apparatus, and the substrate cleaning method according to the present invention are not limited to the above-described embodiments, and various changes can be made.

  For example, it is not always necessary to connect the suction device 40 to the two-fluid nozzle 20, and the suction device 40 can be omitted in the substrate cleaning apparatus 1 as shown in FIG. In this case, even if there is no suction action by the suction device 40, the cleaning fluid droplet having a large diameter is caused to flow in the spiral flow path 20 h of the two-fluid nozzle 20 by the centrifugal force acting on the cleaning liquid droplet. The liquid droplets of the cleaning liquid having a large diameter can be discharged from the flow path 20h through the through holes 20i.

  Moreover, the flow path provided between the confluence | merging part and discharge port in a two-fluid nozzle is not limited to a spiral thing. 5 and 6 show another configuration of the flow path provided between the joining portion of the two-fluid nozzle and the discharge port. FIG. 5 is a cross-sectional view showing details of another configuration of the two-fluid nozzle in the substrate cleaning apparatus shown in FIG. 1, and FIG. 6 schematically shows the flow of the cleaning liquid droplets in the two-fluid nozzle shown in FIG. FIG.

  As shown in FIGS. 5 and 6, in the two-fluid nozzle 21 having another configuration provided in the substrate cleaning apparatus, the nozzle upper body is composed of a nozzle upper body 20 a of the two-fluid nozzle 20 as shown in FIGS. 2 and 3. The configuration is substantially the same. On the other hand, the channel 21d provided in the nozzle inner body 21b of the two-fluid nozzle 21 is not a spiral channel but a channel having a straight portion and a curved portion (see FIG. 6). The droplets of the cleaning liquid generated at the merging portion (not shown) of the two-fluid nozzle 21 are sent to the discharge port 21g of the two-fluid nozzle 21 through this flow path 21d.

  As shown in FIG. 5, a substantially cylindrical nozzle lower body 21 a is provided outside the nozzle inner body 21 b of the two-fluid nozzle 21. A discharge flow path 21c is formed inside the nozzle lower body 21a so that cleaning liquid droplets discharged from a curved portion of the flow path 21d are sent. The curved portion of the flow path 21d and the discharge flow path 21c communicate with each other through a through hole 21e formed so as to penetrate the inner wall of the nozzle lower body 21a. As shown in FIG. 5, the end portion of the through hole 21e communicates with a radially outer portion of the curved portion of the flow path 21d. Here, the radially outer portion of the curved portion of the flow path 21d refers to a portion farthest from the arc center O (see FIG. 5) in the curved portion.

  The discharge flow path 21c provided in the nozzle lower body 21a communicates with the suction pipe 42 through the through hole 21f, and the cleaning liquid sent from the curved portion of the flow path 21d to the through hole 21e. The droplets are sent to the suction pipe 42 through the discharge channel 21c and the through hole 21f, and finally sent to the suction device 40 as shown in FIG. The flow of the cleaning liquid droplet is promoted by suction by the suction device 40.

  FIG. 6 schematically shows the flow of the cleaning liquid droplets in the nozzle inner body 21 b of the two-fluid nozzle 21. As shown in FIG. 6, in the nozzle inner body 21b of the two-fluid nozzle 21, the cleaning liquid droplets sent from the merging portion flow through the straight portion and the curved portion in the flow path 21d, and finally the discharge port 21g. However, of the cleaning liquid droplets flowing through the curved portion of the flow path 21d, some of the cleaning liquid droplets are discharged from the flow path 21d through the through holes 21e. The discharged liquid droplets of the cleaning liquid are sent to a discharge channel 21c inside the nozzle lower body 21a.

  Here, a part of the channel 21d has a curved shape, and the through hole 21e communicates with a radially outer portion of the curved part of the channel 21d. For this reason, among cleaning liquid droplets having various particle diameters flowing through the curved portion of the flow path 21d, the cleaning liquid droplets having a large particle diameter have a greater centrifugal force than the cleaning liquid droplets having a small particle diameter, A droplet of the cleaning liquid having a large particle diameter flows outside in the radial direction in the curved portion of the channel 21d. As a result, a droplet of a cleaning liquid having a large particle diameter is sent to the through hole 21e.

  According to the two-fluid nozzle 21 as shown in FIGS. 5 and 6, like the two-fluid nozzle 20 as shown in FIGS. 2 to 4, a through-hole 21e is formed on the radially outer side of the curved portion of the flow path 21d. In this curved portion, the cleaning liquid droplets flowing outside in the radial direction are discharged from the flow path 21d through the through holes 21e, so that the cleaning liquid droplets having a large particle diameter are discharged. It is discharged from the flow path 21d through the through hole 21e. For this reason, the droplets of the cleaning liquid that are not discharged through the through hole 21e in the flow path 21d and are sent to the discharge port 21g have a small particle diameter. In this way, the droplets of the cleaning liquid sprayed from the discharge port 21g onto the wafer W can be made small in particle diameter.

It is a schematic block diagram which shows the structure of the board | substrate cleaning apparatus in one embodiment of this invention. It is a longitudinal cross-sectional view which shows the detail of a structure of the two fluid nozzle in the board | substrate cleaning apparatus shown in FIG. It is a cross-sectional view by the AA arrow of the two fluid nozzle shown in FIG. It is explanatory drawing which shows roughly the flow of the droplet of the washing | cleaning liquid in the two-fluid nozzle shown in FIG. 2 and FIG. It is a cross-sectional view which shows the detail of the other structure of the two-fluid nozzle in the board | substrate cleaning apparatus shown in FIG. It is explanatory drawing which shows roughly the flow of the droplet of the washing | cleaning liquid in the two fluid nozzle shown in FIG. It is a longitudinal cross-sectional view which shows the detail of a structure of the conventional 2 fluid nozzle. (A) is a figure which shows the outline of the discharge port of the conventional 2 fluid nozzle as shown in FIG. 7, (b) is the relationship between the position in a nozzle discharge port, and the particle diameter of the droplet of a washing | cleaning liquid. It is a graph to show.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate processing apparatus 10 Chamber 12 Spin chuck 16 Outer cylinder 20 Two-fluid nozzle 20a Nozzle upper main body 20b Cleaning liquid flow path 20c Nitrogen gas flow path 20d Merge part 20e Nozzle lower main body 20f Nozzle inner main body 20g Discharge flow path 20h Spiral flow Passage 20i Through-hole 20j Discharge port 20k Through-hole 21 Two-fluid nozzle 21a Nozzle lower main body 21b Nozzle inner main body 21c Discharge flow path 21d Flow path 21e Through-hole 21f Through-hole 21g Discharge port 22 Arm 24 Rotating shaft part 26 Cleaning liquid supply pipe 28 Nitrogen gas supply pipe 30 Cleaning liquid tank 32 Nitrogen gas supply mechanism 34 Valve 36 Valve 38 Filter 40 Aspirator 42 Suction pipe 50 Cleaning liquid discharge pipe 80 Two-fluid nozzle 80a Nozzle body 80b Cleaning liquid flow path 80c Nitrogen gas flow path 80d Merge part 80e Discharge port 86 Cleaning liquid supply pipe 88 Containing gas supply pipe

Claims (5)

A cleaning liquid and a droplet generating gas are supplied from the outside, respectively, and a main body portion in which the cleaning liquid and the droplet generating gas are mixed to generate a cleaning liquid droplet inside,
A flow path provided inside the main body, in which a liquid droplet of the cleaning liquid generated by mixing the cleaning liquid and the liquid droplet generating gas flows, wherein the flow path is at least partially curved;
A discharge port that is provided at a downstream end of the flow path in the main body and sprays droplets of the cleaning liquid sent from the flow path to the outside;
A discharge port that is provided on a radially outer side of the curved portion of the flow path, and discharges the liquid droplets of the cleaning liquid that flows on the radial outer side of the curved portion of the flow path from the flow path;
Equipped with a,
The two-fluid nozzle, wherein the curved portion of the flow path has a spiral shape . The discharge port is provided with a suction mechanism, and when the suction mechanism sucks a droplet of the cleaning liquid flowing on the radially outer side in the curved portion of the flow path, the droplet of the cleaning liquid is discharged from the discharge port. The two-fluid nozzle according to claim 1 , wherein the two-fluid nozzle is discharged from the flow path. A two-fluid nozzle according to claim 1 or 2,
A substrate cleaning apparatus for cleaning a substrate to be processed with droplets of a cleaning liquid sprayed from a discharge port of the two-fluid nozzle. The cleaning liquid and the droplet generating gas are mixed inside the two-fluid nozzle to generate cleaning liquid droplets, and the cleaning liquid droplets are sprayed from the two-fluid nozzle onto the processing target substrate, thereby causing the substrate to be processed. A substrate cleaning method that performs cleaning,
Supplying a cleaning liquid and a droplet generating gas to the two-fluid nozzle, and mixing the cleaning liquid and the droplet generating gas inside the two-fluid nozzle to generate cleaning liquid droplets;
A step of flowing a droplet of the cleaning liquid through a flow path at least partially curved, and discharging the liquid droplet of the cleaning liquid flowing outside in the radial direction in the curved portion of the flow path from the flow path through the discharge port; ,
Spraying droplets of the cleaning liquid that have not been discharged in the flow path from the discharge port of the two-fluid nozzle onto the substrate to be processed;
Equipped with a,
The substrate cleaning method, wherein the curved portion of the flow path has a spiral shape .   5. The substrate cleaning method according to claim 4, wherein the cleaning liquid droplets are discharged from the flow path by sucking the liquid droplets of the cleaning liquid flowing radially outside the curved portion of the flow path from the outside. .

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