JP5512424B2 - Substrate cleaning apparatus and substrate cleaning method - Google Patents

Description

  The present invention relates to a substrate cleaning apparatus and a substrate cleaning method for cleaning a substrate, and in particular, it is possible to sufficiently remove particles and the like attached to the surface of a substrate while suppressing destruction of a device pattern of the substrate. The present invention relates to a substrate cleaning apparatus and a substrate cleaning method capable of improving cleaning performance.

  In a semiconductor device manufacturing process, if various processes are performed with particles adhering to a semiconductor wafer (hereinafter also simply referred to as a wafer), normal processes cannot be performed and the yield deteriorates. Therefore, it is necessary to perform a wafer cleaning process.

  As a wafer cleaning method, for example, a cleaning liquid film is generated on the surface of the wafer by supplying a cleaning liquid composed of pure water or chemicals to the surface while rotating the wafer on a spin chuck, and a liquid film is generated on the surface. A method is known in which particles adhered to the surface of the wafer are removed by spraying cleaning liquid droplets onto the wafer that has been further sprayed by a two-fluid nozzle, and finally the wafer is dried by rotating the wafer at a high speed. .

  By the way, along with the thinning of the wafer device pattern (hereinafter also simply referred to as a pattern), the pattern is prevented from being destroyed by the cleaning liquid droplets ejected from the two-fluid nozzle and adhered to the wafer surface. There is a need to both sufficiently remove the generated particles.

  As a method for effectively removing particles adhering to the surface of a wafer, there is a method in which droplets of a cleaning liquid are ejected by a two-fluid nozzle into an area where a liquid film is thinned by gas ejection by a gas nozzle (for example, Patent Document 1). reference).

JP 2009-246190 A

  However, in the method as disclosed in Patent Document 1, gas is injected before the droplet of the cleaning liquid is injected in the scanning direction (movement direction) of the nozzle, or concentric circles arranged so as to surround the two-fluid nozzle. The thickness of the liquid film of the cleaning liquid cannot be controlled to a desired thickness because the gas is injected in the shape of both, and both the suppression of pattern destruction and the sufficient removal of particles The effect was not obtained. More specifically, when the gas nozzle and the two-fluid nozzle are arranged along the scanning direction (movement direction) of the nozzle as shown in Patent Document 1, gas is jetted onto the liquid film of the cleaning liquid to form the liquid film. It takes time for the wafer to rotate at least once until the droplet of the cleaning liquid is sprayed on the thinned portion of the liquid film after the film is thinned. The liquid film of the cleaning liquid has the original thickness during one rotation of the wafer. May return. Further, when the gas is injected concentrically, a swell of the liquid film is generated inside the gas injected concentrically, and the thickness of the liquid film cannot be controlled.

  The present invention has been made in consideration of such points, and the thickness of the liquid film of the cleaning liquid on the surface of the substrate at the location where the liquid droplets of the cleaning liquid are to be ejected is controlled to be constant at a desired thickness. Provides a substrate cleaning apparatus and a substrate cleaning method capable of sufficiently removing particles and the like attached to the surface of the substrate while suppressing the destruction of the device pattern of the substrate and improving the cleaning performance for the substrate. The purpose is to do.

  In the substrate cleaning apparatus of the present invention, a holding unit that holds and rotates the substrate, and a cleaning liquid and a droplet generation gas are mixed to generate a droplet of the cleaning liquid, and the substrate held by the holding unit A two-fluid nozzle that ejects droplets of the cleaning liquid and a gas nozzle that ejects gas to the substrate held by the holding unit, and gas is injected by the gas nozzle on the substrate held by the holding unit. The two-fluid nozzle and the gas nozzle are arranged so that the position at which the droplet of the cleaning liquid is ejected by the two-fluid nozzle is upstream in the rotation direction of the substrate.

  In the substrate cleaning apparatus of the present invention, the two-fluid nozzle is movable in the peripheral direction from the center of the substrate held by the holding portion, and the gas nozzle is more than the two-fluid nozzle in the rotation direction of the substrate. Also, at the upstream location, it may be movable in the peripheral direction from the center of the substrate held by the holding portion.

  At this time, the two-fluid nozzle and the gas nozzle may move integrally, and the gas nozzle may always be located upstream of the two-fluid nozzle in the rotation direction of the substrate.

  In this case, the distance between the two-fluid nozzle and the gas nozzle may be changed.

  The substrate cleaning apparatus of the present invention may further include a rinse nozzle for generating a liquid film of the cleaning liquid on the surface of the substrate held by the holding unit.

  In the substrate cleaning apparatus of the present invention, the distance between the surface of the substrate held by the holding unit and the gas nozzle may be changed.

  At this time, the distance between the surface of the substrate held by the holding unit and the gas nozzle may be adjusted based on the size and flow velocity of the droplets ejected from the two-fluid nozzle. Good.

  In the substrate cleaning apparatus of the present invention, the gas nozzle may be configured to change the amount of gas jetted onto the substrate held by the holding unit.

  At this time, the injection amount of the gas from the gas nozzle may be adjusted based on the size and flow velocity of the droplets injected from the two-fluid nozzle.

  The substrate cleaning method of the present invention includes a step of holding and rotating a substrate by a holding unit, a step of generating a liquid film of a cleaning solution on the surface of the substrate held by the holding unit, and a substrate held by the holding unit. And a step of controlling the thickness of the liquid film of the cleaning liquid on the surface of the substrate to a desired thickness, and the thickness of the liquid film of the cleaning liquid on the substrate held by the holding unit to a desired thickness And a step of ejecting droplets of the cleaning liquid generated by mixing the cleaning liquid and the droplet generation gas at a controlled location, and the gas is injected on the substrate held by the holding unit The position is characterized in that the position is on the upstream side in the rotation direction of the substrate from the position where the droplet of the cleaning liquid is ejected.

  In the substrate cleaning method of the present invention, the distance between the surface of the substrate held by the holding portion and the gas nozzle for injecting gas onto the substrate may be changed.

  At this time, the distance between the surface of the substrate held by the holding unit and the gas nozzle may be adjusted based on the size and flow velocity of the droplets ejected onto the substrate.

  In the substrate cleaning method of the present invention, the gas injection amount to the substrate held by the holding unit may be changed.

  At this time, the amount of gas injected onto the substrate may be adjusted based on the size and flow velocity of the droplets injected onto the substrate.

  In the substrate cleaning method of the present invention, the two-fluid nozzle for injecting the droplet of the cleaning liquid onto the substrate is movable in the peripheral direction from the center of the substrate held by the holding unit, and injects the gas onto the substrate. The gas nozzle may be movable in the peripheral direction from the center of the substrate held by the holding portion at a location upstream of the two-fluid nozzle in the rotation direction of the substrate.

  At this time, the two-fluid nozzle and the gas nozzle may move integrally, and the gas nozzle may always be located upstream of the two-fluid nozzle in the rotation direction of the substrate.

  In this case, the distance between the two-fluid nozzle and the gas nozzle may be changed.

  According to the substrate cleaning apparatus and the substrate cleaning method of the present invention, it is possible to control the thickness of the liquid film of the cleaning liquid on the surface of the substrate at the position where the liquid droplets of the cleaning liquid are to be jetted to make it constant at a desired thickness. In addition, particles and the like attached to the surface of the substrate can be sufficiently removed while suppressing the destruction of the device pattern of the substrate, and the cleaning performance for the substrate can be improved.

It is a schematic block diagram which shows the structure of the board | substrate cleaning apparatus in one embodiment of this invention. FIG. 2 is a top view showing the positional relationship of each nozzle when a wafer held by a spin chuck is viewed from above in the substrate cleaning apparatus shown in FIG. 1. It is a sectional side view by the AA arrow of the wafer and each nozzle shown in FIG. It is a figure which expands and shows a state when the droplet of a cleaning liquid is sprayed on a wafer. 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. FIG. 6 is a side sectional view showing a state in which nitrogen gas is jetted obliquely downward with respect to a wafer by a gas nozzle in another substrate cleaning apparatus according to the present invention. FIG. 10 is a top view showing the positional relationship of each nozzle when a wafer held by a spin chuck is viewed from above in still another substrate cleaning apparatus according to the present invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 5 are views showing an embodiment of a substrate cleaning apparatus and a substrate cleaning method according to the present invention. Among these, FIG. 1 is a schematic configuration diagram showing the configuration of the substrate cleaning apparatus in the present embodiment, and FIG. 2 is a top view of the wafer held by the spin chuck in the substrate cleaning apparatus shown in FIG. It is a top view which shows the positional relationship of each nozzle at the time. 3 is a side sectional view of the wafer and each nozzle shown in FIG. 2 taken along the line AA, and FIG. 4 is an enlarged view showing a state when a droplet of cleaning liquid is ejected onto the wafer. It is. FIG. 5 is a longitudinal sectional view showing details of the configuration of the two-fluid nozzle in the substrate cleaning apparatus shown in FIG.

  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. An outer cylinder 16 is provided in the chamber 10 so as to cover the wafer W held by the spin chuck 12. Hereinafter, details of each component of the substrate cleaning apparatus 1 will be described.

  The spin chuck 12 rotates the wafer W while holding it 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 rinse nozzle 20 (described later) or the two-fluid nozzle 30 (described later) to the wafer W held on the spin chuck 12, an outer cylinder is formed on the side of the wafer W held on the spin chuck 12. Sixteen sidewalls can be located. Such a spin chuck 12 constitutes a holding unit that holds and rotates the wafer W.

  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 rinse nozzle 20, a two-fluid nozzle 30, and a gas nozzle 40 are respectively provided downward at a position above the wafer W when held by the spin chuck 12 in the chamber 10. The rinse nozzle 20 supplies a cleaning liquid to the surface of the wafer W held by the spin chuck 12 and generates a liquid film of the cleaning liquid on the surface of the wafer W. Further, the two-fluid nozzle 30 ejects droplets of the cleaning liquid onto the wafer W on which a liquid film of the cleaning liquid is generated, and removes particles and the like attached to the surface of the wafer W. Further, the gas nozzle 40 is held by the spin chuck 12 and jets gas onto the wafer W on which a liquid film of cleaning liquid is generated. Hereinafter, the details of the configuration of each nozzle 20, 30, 40 will be described.

  As shown in FIGS. 1 and 2, the rinse nozzle 20 is disposed at a position spaced upward from the center of the wafer W held by the spin chuck 12 when the wafer W is cleaned. ing. More specifically, as shown in FIG. 1, the rinse nozzle 20 is connected to the rotary shaft portion 28 via the arm 26. The rotary shaft portion 28 is provided with an arm drive mechanism (not shown) that rotates the rotary shaft portion 28 in both forward and reverse directions. The arm driving mechanism rotates the arm 26 in the horizontal direction around the rotation shaft portion 28, thereby moving the rinse nozzle 20 from a position above the center portion of the wafer W to a position outside the peripheral portion of the wafer W. It is designed to reciprocate along a horizontal plane within the range of. Accordingly, when performing the cleaning process on the wafer W, the rinse nozzle 20 is disposed at a position above the center of the wafer W, while the wafer W is placed on the spin chuck 12 from the outside of the chamber 10. When the wafer W is removed from the spin chuck 12 and transferred to the outside of the chamber 10, the rinse nozzle 20 is moved to a position outside the peripheral edge of the wafer W. Further, the arm drive mechanism can reciprocate the rotary shaft portion 28 in the vertical direction. As a result, the distance between the tip of the rinse nozzle 20 and the wafer W held by the spin chuck 12 can be adjusted.

  As shown in FIG. 1, a cleaning liquid supply pipe 24 is connected to the rinse nozzle 20, and the cleaning liquid is supplied to the rinse nozzle 20 through the cleaning liquid supply pipe 24. A cleaning liquid tank 22 is provided at the upstream end of the cleaning liquid supply pipe 24, and cleaning liquid made of pure water or chemical liquid is stored in the cleaning liquid tank 22. The cleaning liquid is sent from the cleaning liquid tank 22 to the cleaning liquid supply pipe 24 by a pumping means (not shown) such as a pump. The cleaning liquid supply pipe 24 is provided with a valve 24a capable of adjusting the opening degree.

  As shown in FIG. 1, the two-fluid nozzle 30 and the gas nozzle 40 are each attached to an arm 48. FIG. 1 merely schematically shows an example in which the two-fluid nozzle 30 and the gas nozzle 40 are attached to the arm 48, but the detailed attachment positions of the two-fluid nozzle 30 and the gas nozzle 40 with respect to the arm 48 will be described. As shown in FIG. 2, in the wafer W held by the spin chuck 12, the position in which the gas is ejected by the gas nozzle 40 is greater than the position in which the cleaning fluid droplets are ejected by the two-fluid nozzle 30. The attachment positions of the two-fluid nozzle 30 and the gas nozzle 40 with respect to the arm 48 are set so as to be upstream. That is, as shown in FIG. 3, the gas nozzle 40 injects gas onto the wafer W held by the spin chuck 12 to control the thickness of the liquid film C of the cleaning liquid on the surface of the wafer W to a desired thickness. Positional relationship between the two-fluid nozzle 30 and the gas nozzle 40 respectively attached to the arm 48 so that the two-fluid nozzle 30 ejects a droplet of the cleaning liquid at a position where the thickness of the liquid film C of the cleaning liquid is controlled to a desired thickness. Is set. Further, the positional relationship between the two-fluid nozzle 30 and the gas nozzle 40 is such that the droplets of the cleaning liquid ejected from the two-fluid nozzle 30 are not disturbed by the gas ejected from the gas nozzle 40. . In FIG. 3, the rotation direction of the wafer W held by the spin chuck 12 is the left direction.

  The arm 48 to which the two-fluid nozzle 30 and the gas nozzle 40 are attached is connected to the rotating shaft portion 46. The rotary shaft portion 46 is provided with an arm drive mechanism (not shown) that rotates the rotary shaft portion 46 in both forward and reverse directions. The arm driving mechanism rotates the arm 48 in the horizontal direction around the rotation shaft portion 46, thereby moving the two-fluid nozzle 30 and the gas nozzle 40 from the upper position near the center portion of the wafer W to the peripheral portion of the wafer W. It is designed to reciprocate along a horizontal plane within the range up to the outer position. At this time, the two-fluid nozzle 30 and the gas nozzle 40 are integrally moved while the gas nozzle 40 is always positioned on the upstream side of the two-fluid nozzle 30 in the rotation direction of the wafer W. Thus, the two-fluid nozzle 30 can reciprocate along the radial direction of the wafer W held by the spin chuck 12, and the gas nozzle 40 is a two-fluid nozzle in the rotation direction of the wafer W by the spin chuck 12. At a location upstream of 30, the wafer can be reciprocated along the radial direction of the wafer W held by the spin chuck 12.

  Further, the arm drive mechanism can reciprocate the rotary shaft portion 46 in the vertical direction. Thus, the distance between the tips of the two-fluid nozzle 30 and the gas nozzle 40 and the wafer W held by the spin chuck 12 can be adjusted. Further, in the substrate cleaning apparatus 1 according to the present embodiment, the mounting height of the gas nozzle 40 with respect to the arm 48 can also be adjusted.

  As shown in FIG. 1, a cleaning liquid supply pipe 34 is connected to the two-fluid nozzle 30, and the cleaning liquid is supplied to the two-fluid nozzle 30 through the cleaning liquid supply pipe 34. A cleaning liquid tank 32 is provided at the upstream end of the cleaning liquid supply pipe 34, and cleaning liquid made of pure water or chemical liquid is stored in the cleaning liquid tank 32. The cleaning liquid is sent from the cleaning liquid tank 32 to the cleaning liquid supply pipe 34 by a pumping means (not shown) such as a pump. The cleaning liquid supply pipe 34 is provided with a valve 34a capable of adjusting the opening degree.

  Further, a nitrogen gas supply pipe 36 is connected to the two-fluid nozzle 30, and nitrogen gas as a droplet generating gas is supplied to the two-fluid nozzle 30 through the nitrogen gas supply pipe 36. Yes. Note that clean air may be used as the droplet generation gas instead of nitrogen gas. A nitrogen gas supply mechanism 38 is provided at the upstream end of the nitrogen gas supply pipe 36, and the nitrogen gas supply mechanism 38 can supply high-pressure nitrogen gas to the nitrogen gas supply pipe 36. Yes. The nitrogen gas supply pipe 36 is provided with a valve 36a. By changing the opening degree of the valve 36a and changing the pressure (flow rate) of the nitrogen gas sent to the two-fluid nozzle 30, the particle size and flow velocity of the cleaning liquid droplets generated in the two-fluid nozzle 30 can be changed. it can. As a result, the cleaning performance of the wafer W by the droplets of the cleaning liquid can be changed.

  The configuration of the two-fluid nozzle 30 will be specifically described with reference to FIG. FIG. 5 is a longitudinal sectional view of the two-fluid nozzle 30. The two-fluid nozzle generally refers to a nozzle that generates fine droplets by mixing a gas and a liquid and ejects the fine droplets. In FIG. 5, a region indicated by a two-dot chain line 31 indicates an ejection range of cleaning liquid droplets ejected from the two-fluid nozzle 30. As described above, the two-fluid nozzle 30 is supplied with a cleaning liquid such as pure water or a chemical liquid via the cleaning liquid supply pipe 34 and also supplied with nitrogen gas from the nitrogen gas supply pipe 36.

  More specifically, the two-fluid nozzle 30 has a substantially cylindrical nozzle body 30a formed of, for example, a fluororesin, and the cleaning liquid that communicates with the cleaning liquid supply pipe 34 is provided inside the nozzle body 30a. A flow path 30b and a nitrogen gas flow path 30c communicating with the nitrogen gas supply pipe 36 are provided. The cleaning liquid flow path 30b and the nitrogen gas flow path 30c are merged at the lower end of the nozzle body 30a, and the cleaning liquid sent from the cleaning liquid flow path 30b and the nitrogen gas flow path are joined at the merged location 30d. The nitrogen gas sent from 30c collides and mixes, whereby a droplet of the cleaning liquid is formed at the junction 30d. The droplet of the cleaning liquid is lowered from the lower end of the nozzle body 30a with respect to the wafer W. Is to be injected.

  As shown in FIG. 1, a nitrogen gas supply pipe 44 is connected to the gas nozzle 40, and nitrogen gas is supplied to the gas nozzle 40 through the nitrogen gas supply pipe 44. A nitrogen gas supply mechanism 42 is provided at the upstream end of the nitrogen gas supply pipe 44, and the nitrogen gas supply mechanism 42 can supply high-pressure nitrogen gas to the nitrogen gas supply pipe 44. Yes. The nitrogen gas supply pipe 44 is provided with a valve 44a. By changing the opening degree of the valve 44a and changing the pressure (flow rate) of nitrogen gas sent to the gas nozzle 40, the amount of gas injected onto the wafer W by the gas nozzle 40 can be changed. . Note that clean air may be supplied to the gas nozzle 40 instead of nitrogen gas.

  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, the cleaning liquid is supplied to the surface of the wafer W held by the spin chuck 12 and rotating in the chamber 10 by the rinse nozzle 20, and a liquid film of the cleaning liquid is generated on the surface of the wafer W. Specifically, by supplying a cleaning liquid to the surface of the wafer W by the rinse nozzle 20, a liquid film having a thickness in the range of 50 μm to 1000 μm is generated. However, the thickness of the cleaning liquid film also depends on the number of rotations of the wafer W.

  After a liquid film of the cleaning liquid is generated on the surface of the wafer W held and rotated by the spin chuck 12, a cleaning liquid droplet is ejected to the center of the wafer W by the two-fluid nozzle 30, and by the gas nozzle 40. Inject gas. At this time, as shown in FIG. 2, in the wafer W held by the spin chuck 12, the position where the gas is ejected by the gas nozzle 40 is higher than the position where the droplet of the cleaning liquid is ejected by the two-fluid nozzle 30. As shown in FIG. 3, first, the thickness of the liquid film C of the cleaning liquid on the surface of the wafer W is controlled to a desired thickness, as shown in FIG. A droplet of the cleaning liquid is ejected from the two-fluid nozzle 30 to a location where the thickness is controlled to a desired thickness. More specifically, when the gas nozzle 40 injects nitrogen gas onto the wafer W, the thickness of the liquid film C of the cleaning liquid on the surface of the wafer W is controlled to 1 μm to 10 μm. Liquid droplets of the cleaning liquid are ejected onto the portion of the wafer W where the liquid film C exists on the surface. And the state which injects the washing | cleaning liquid from the two fluid nozzle 30 to the location where the thickness of the liquid film C was controlled is maintained, and the two fluid nozzle 30 and the gas nozzle 40 are toward the peripheral part from the center part of the wafer W. Moving.

  Then, as shown in FIG. 4, the droplets D of the cleaning liquid are ejected onto the wafer W on which the liquid film C of the cleaning liquid is present, whereby the particles P attached to the wafer W are removed. Here, the ejection force of the cleaning liquid droplet D (physical force given by the droplet) ejected from the two-fluid nozzle 30 onto the wafer W and the ejection force of the gas ejected from the gas nozzle 40 are: The device pattern W1 (hereinafter also referred to as the pattern W1) is set to a size that does not destroy the device pattern W1. More specifically, the jetting force of the droplet D is caused by the particle diameter of the droplet D of the cleaning liquid ejected from the two-fluid nozzle 30 being relatively large or the flow velocity of the droplet D of the cleaning liquid being relatively large. Is relatively large, the cleaning liquid film C is controlled to be relatively thick by reducing the injection force of the gas injected from the gas nozzle 40. On the other hand, since the particle diameter of the droplet D of the cleaning liquid ejected from the two-fluid nozzle 30 is relatively small or the flow velocity of the droplet D of the cleaning liquid is relatively small, the ejection force of the droplet D is relatively small. If it is small, the cleaning liquid film C is controlled to be relatively thin by increasing the injection force of the gas injected from the gas nozzle 40.

  Thereafter, the rinse nozzle 20, the two-fluid nozzle 30 and the gas nozzle 40 are moved outward from the peripheral edge of the wafer W, and the spin chuck drive 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 for cleaning the wafer W by the substrate cleaning apparatus 1 is completed.

  As described above, according to the substrate cleaning apparatus 1 of the present embodiment, on the wafer W held by the spin chuck 12, the gas nozzle 40 ejects the cleaning liquid droplets at the position where the gas nozzle 40 ejects the cleaning liquid. The two-fluid nozzle 30 and the gas nozzle 40 are arranged so as to be on the upstream side in the rotation direction of the wafer W with respect to the position where they are formed. As a result, the thickness of the liquid film of the cleaning liquid at the location of the wafer W where the liquid droplets of the cleaning liquid are to be ejected by the two-fluid nozzle 30 can be controlled to a desired thickness. The film thickness can be made constant. For this reason, the thickness of the liquid film of the cleaning liquid can be controlled in accordance with the speed and size of the liquid droplet of the cleaning liquid to be sprayed onto the wafer W by the two-fluid nozzle 30. As a result, it is possible to transmit the action of the cleaning liquid droplets to the surface of the wafer W while suppressing the pattern of the wafer W from being destroyed by the cleaning liquid droplets. The cleaning performance for the wafer W can be improved.

  Further, according to the substrate cleaning method of the present embodiment, gas is jetted onto the wafer W held by the spin chuck 12, and the thickness of the liquid film of the cleaning liquid on the surface of the wafer W is controlled to a desired thickness. The liquid droplets of the cleaning liquid are ejected to a location where the thickness of the liquid film of the cleaning liquid on the wafer W is controlled to a desired thickness. For this reason, the thickness of the liquid film of the cleaning liquid can be controlled in accordance with the speed and size of the liquid droplet of the cleaning liquid to be sprayed onto the wafer W by the two-fluid nozzle 30. As a result, it is possible to transmit the action of the cleaning liquid droplets to the surface of the wafer W while suppressing the pattern of the wafer W from being destroyed by the cleaning liquid droplets. The cleaning performance for the wafer W can be improved.

  Further, in the substrate cleaning apparatus 1 of the present embodiment, as shown in FIG. 2, the two-fluid nozzle 30 is reciprocally movable along the radial direction of the wafer W held by the spin chuck 12. The gas nozzle 40 is reciprocally movable along the radial direction of the wafer W held by the spin chuck 12 at a location upstream of the two-fluid nozzle 30 in the rotation direction of the wafer W by the spin chuck 12. Here, since the two-fluid nozzle 30 and the gas nozzle 40 are respectively attached to the arm 48, the two-fluid nozzle 30 and the gas nozzle 40 can move integrally, and the gas nozzle 40 is always in the direction of rotation of the wafer W. 30 on the upstream side.

  In the substrate cleaning apparatus 1 of the present embodiment, when the two-fluid nozzle 30 and the gas nozzle 40 are attached to the arm 48, the distance between the two-fluid nozzle 30 and the gas nozzle 40 can be changed. It may be. In this case, by adjusting the distance between the two-fluid nozzle 30 and the gas nozzle 40, the cleaning liquid on the wafer W that is controlled by gas injection from the gas nozzle 40 at a position directly below the two-fluid nozzle 30 is adjusted. The thickness of the liquid film can be adjusted in accordance with the flow velocity and size of the cleaning liquid droplets ejected from the two-fluid nozzle 30. That is, when the distance between the two-fluid nozzle 30 and the gas nozzle 40 is reduced, the gas nozzle 40 comes closer to the two-fluid nozzle 30, and thus the liquid film of the cleaning liquid on the wafer W at a position directly below the two-fluid nozzle 30. The thickness of is relatively small. On the other hand, when the distance between the two-fluid nozzle 30 and the gas nozzle 40 is increased, the gas nozzle 40 is moved away from the two-fluid nozzle 30, so that the liquid film of the cleaning liquid on the wafer W at a position directly below the two-fluid nozzle 30 is used. The thickness becomes relatively large.

  Further, in the substrate cleaning apparatus 1 of the present embodiment, a rinse nozzle 20 is further provided for generating a liquid film of the cleaning liquid on the surface of the wafer W held by the spin chuck 12. For this reason, the rinse nozzle 20 can generate a liquid film of the cleaning liquid on the surface of the wafer W.

  Further, in the substrate cleaning apparatus 1 of the present embodiment, the arm drive mechanism provided on the rotary shaft portion 46 can reciprocate the rotary shaft portion 46 in the vertical direction. Further, the mounting height of the gas nozzle 40 with respect to the arm 48 can be adjusted. As a result, the distance between the surface of the wafer W held by the spin chuck 12 and the gas nozzle 40 can be changed. For this reason, by adjusting the distance between the surface of the wafer W held by the spin chuck 12 and the gas nozzle 40, the wafer is controlled by gas injection from the gas nozzle 40 at a location directly below the two-fluid nozzle 30. The thickness of the liquid film of the cleaning liquid on W can be adjusted in accordance with the flow velocity and size of the cleaning liquid droplets ejected from the two-fluid nozzle 30.

  Further, in the substrate cleaning apparatus 1 of the present embodiment, a valve 44a is interposed in the nitrogen gas supply pipe 44, and the pressure (flow rate) of nitrogen gas sent to the gas nozzle 40 is changed by changing the opening of the valve 44a. By changing the above, it is possible to change the amount of gas injected onto the wafer W by the gas nozzle 40. For this reason, the liquid of the cleaning liquid on the wafer W controlled by the gas injection from the gas nozzle 40 at the position just below the two-fluid nozzle 30 by adjusting the injection amount of the gas injected onto the wafer W by the gas nozzle 40. The thickness of the film can be adjusted in accordance with the flow velocity and size of the cleaning liquid droplets ejected from the two-fluid nozzle 30.

  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, the gas nozzle 40 is not limited to the one that injects the gas directly below the wafer W. As shown in FIG. 6, the gas nozzle 40 may inject gas onto the wafer W while being inclined with respect to the vertical direction (vertical direction in FIG. 6). However, the gas nozzle 40 is inclined so as not to inject the gas toward the two-fluid nozzle 30. In this case, gas is injected from the upper side of the cleaning liquid film generated on the surface of the wafer W, not from directly above, but even at this time, as shown in FIG. The thickness of the liquid film C of the cleaning liquid on the surface is controlled to a desired thickness, and the two-fluid nozzle 30 applies a liquid droplet of the cleaning liquid to a location where the thickness of the liquid film C of the cleaning liquid is controlled to the desired thickness. It comes to inject. In FIG. 6, the rotation direction of the wafer W held by the spin chuck 12 is the left direction. As shown in FIG. 6, even when gas is jetted from above rather than directly above the liquid film of the cleaning liquid generated on the surface of the wafer W, droplets of the cleaning liquid are jetted by the two-fluid nozzle 30. The thickness of the liquid film of the cleaning liquid at the position of the wafer W to be controlled can be controlled to a desired thickness, and the thickness of the liquid film can be made constant with this controlled size. For this reason, the thickness of the liquid film of the cleaning liquid can be controlled in accordance with the speed and size of the liquid droplet of the cleaning liquid to be sprayed onto the wafer W by the two-fluid nozzle 30.

  The cross-sectional shape of the gas nozzle 40 is not limited to a circular shape. Another configuration of the gas nozzle 40 will be described with reference to FIG. In the substrate cleaning apparatus as shown in FIG. 7, a slit type gas nozzle 40 a is provided instead of the gas nozzle 40 having a circular cross-sectional shape. The cross-sectional shape of the gas nozzle 40 a is the wafer W held by the spin chuck 12. It is an elongated rectangle extending in the radial direction. As long as the gas nozzle 40a as shown in FIG. 7 is located upstream of the two-fluid nozzle 30 in the rotation direction of the wafer W, the position may be fixed, or the two-fluid nozzle 30 may be fixed. And may move together. Even when the gas nozzle 40a as shown in FIG. 7 is used, as in the case of using the gas nozzle 40 as shown in FIG. 2 and the like, the cleaning liquid at the position of the wafer W where the liquid droplets of the cleaning liquid are to be ejected by the two-fluid nozzle 30 is used. The thickness of the liquid film can be controlled to a desired thickness, and the thickness of the liquid film can be made constant with this controlled size. For this reason, the thickness of the liquid film of the cleaning liquid can be controlled in accordance with the speed and size of the liquid droplet of the cleaning liquid to be sprayed onto the wafer W by the two-fluid nozzle 30.

  As another example of the substrate processing apparatus, instead of providing a gas nozzle, the wafer W held by the spin chuck 12 is positioned at a location upstream of the two-fluid nozzle 30 in the rotation direction of the wafer W. An absorbing member (not shown) such as a sponge that absorbs the liquid film of the cleaning liquid on W is provided, or a baffle plate (not shown) is provided at a slight distance from the wafer W held by the spin chuck 12. May be. Even when such an absorbing member or baffle plate is provided, the liquid of the cleaning liquid at the position of the wafer W where the liquid droplets of the cleaning liquid are to be ejected by the two-fluid nozzle 30 is the same as when the gas is ejected to the wafer W by the gas nozzle. The thickness of the film can be controlled to a desired thickness, and the thickness of the liquid film can be made constant with this controlled size. For this reason, the thickness of the liquid film of the cleaning liquid can be controlled in accordance with the speed and size of the liquid droplet of the cleaning liquid to be sprayed onto the wafer W by the two-fluid nozzle 30.

DESCRIPTION OF SYMBOLS 1 Substrate cleaning apparatus 10 Chamber 12 Spin chuck 16 Outer cylinder 20 Rinse nozzle 22 Cleaning liquid tank 24 Cleaning liquid supply pipe 24a Valve 26 Arm 28 Rotating shaft part 30 Two-fluid nozzle 30a Nozzle main body 30b Cleaning liquid flow path 30c Nitrogen gas flow path 30d Merge point 31 Cleaning liquid droplet injection range 32 Cleaning liquid tank 34 Cleaning liquid supply pipe 34a Valve 36 Nitrogen gas supply pipe 36a Valve 38 Nitrogen gas supply mechanism 40, 40a Gas nozzle 42 Nitrogen gas supply mechanism 44 Nitrogen gas supply pipe 46 Rotating shaft 48 Arm 50 Cleaning liquid Discharge pipe W Wafer W1 Device pattern C Cleaning liquid film D Cleaning liquid droplet P Particle

Claims (10)

A holding unit for holding and rotating the substrate;
A rinse nozzle for generating a liquid film of the cleaning liquid on the surface of the substrate held by the holding unit;
A two-fluid nozzle that mixes a cleaning liquid and a droplet generating gas to generate cleaning liquid droplets and injects the cleaning liquid droplets onto the substrate held by the holding unit;
A gas nozzle for injecting gas to the substrate held by the holding unit;
With
In the substrate held by the holding unit, the two-fluid nozzle is arranged such that the position at which the gas nozzle ejects gas is upstream in the rotation direction of the substrate with respect to the position at which the droplet of cleaning liquid is ejected by the two-fluid nozzle. And the gas nozzle is arranged ,
The injection position of the gas nozzle on the upstream side in the rotation direction is changed by changing the injection amount of the gas at the injection position of the gas nozzle on the upstream side in the rotation direction according to the size or flow velocity of the liquid picking at the injection position of the two-fluid nozzle. substrate cleaning apparatus characterized that you adjust the thickness of the cleaning liquid of the liquid film in. The two-fluid nozzle is movable in the peripheral direction from the center of the substrate held by the holding part,
2. The gas nozzle is movable in a peripheral direction from a center of a substrate held by the holding portion at a location upstream of the two-fluid nozzle in the rotation direction of the substrate. Substrate cleaning equipment.   The two-fluid nozzle and the gas nozzle move integrally, and the gas nozzle is always positioned upstream of the two-fluid nozzle in the rotation direction of the substrate. 2. The substrate cleaning apparatus according to 2.   The substrate cleaning apparatus according to claim 3, wherein a distance between the two-fluid nozzle and the gas nozzle can be changed. The substrate cleaning apparatus according to any one of claims 1 to 4, characterized in that distance and is capable of changing the between the surface and the gas nozzle of the substrate held by the holding portion . A step of holding and rotating the substrate by the holding unit;
Generating a liquid film of the cleaning liquid on the surface of the substrate held by the holding unit;
Injecting gas onto the substrate held by the holding unit to control the thickness of the liquid film of the cleaning liquid on the surface of the substrate to a desired thickness;
The droplets of the cleaning liquid generated by mixing the cleaning liquid and the liquid droplet generating gas are jetted to the location where the thickness of the liquid film of the cleaning liquid on the substrate held by the holding unit is controlled to a desired thickness. And a process of
With
In the substrate held by the holding unit, the position at which the gas is ejected is upstream in the rotation direction of the substrate with respect to the position at which the cleaning liquid droplets are ejected .
The control step includes changing the gas injection amount at the gas injection position on the upstream side in the rotation direction according to the size or flow rate of the liquid extraction at the position where the liquid extraction of the mixed cleaning liquid is injected. the substrate cleaning method characterized that you adjust the thickness of the cleaning liquid of the liquid film at the ejection position of the gas upstream side in the direction of rotation. 7. The substrate cleaning method according to claim 6 , wherein a distance between a surface of the substrate held by the holding unit and a gas nozzle for injecting gas to the substrate can be changed. The two-fluid nozzle that ejects a droplet of cleaning liquid onto the substrate is movable in the peripheral direction from the center of the substrate held by the holding unit,
The gas nozzle for injecting gas to the substrate is movable in the peripheral direction from the center of the substrate held by the holding portion at a location upstream of the two-fluid nozzle in the rotation direction of the substrate. The substrate cleaning method according to claim 6 or 7 . The two-fluid nozzle and the gas nozzle move integrally, and the gas nozzle is always positioned upstream of the two-fluid nozzle in the rotation direction of the substrate. 9. The substrate cleaning method according to 8 . The substrate cleaning method according to claim 9 , wherein a distance between the two-fluid nozzle and the gas nozzle can be changed.

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