JP5528927B2 - 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 more particularly to a substrate cleaning apparatus and a substrate cleaning method capable of improving the cleaning performance for a substrate while suppressing destruction of a device pattern of the substrate.

  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 formed on the surface of the wafer by supplying a cleaning liquid composed of pure water or chemicals to the surface of the wafer while rotating the wafer on a spin chuck. 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. (For example, refer patent document 1 etc.).

JP 2003-209087 A

  In the wafer cleaning method as described above, the boundary layer B is formed on the liquid film C of the cleaning liquid formed on the surface of the wafer W as shown in FIG. Here, the boundary layer B refers to a portion of the liquid film C of the cleaning liquid on the wafer W that is generated at a portion in contact with the surface of the wafer W and where the liquid cannot flow. Thus, in a state where the liquid cannot flow in the boundary layer B, in order to move and remove the particles P adhering to the wafer W from the surface of the wafer W, the cleaning liquid sprayed to the wafer W by the two-fluid nozzle The physical force exerted by the cleaning liquid droplet D on the surface of the wafer W must be increased by increasing the size of the droplet D or increasing the speed of the droplet D. However, if the physical force exerted on the surface of the wafer W by the droplet D of the cleaning liquid ejected onto the wafer W by the two-fluid nozzle increases, this pattern is generated when the device pattern W1 of the wafer W is miniaturized. There is a risk of destroying W1.

  The present invention has been made in consideration of such points, and by generating convection between the boundary layer in the liquid film of the cleaning liquid formed on the surface of the substrate and the region above the boundary layer. By eliminating the boundary layer and making particles attached to the surface of the substrate easily separate from the surface of the substrate, particles attached to the surface of the substrate can be removed even when the physical force of the liquid supplied to the substrate is small. An object of the present invention is to provide a substrate cleaning apparatus and a substrate cleaning method that can be sufficiently removed and can improve the cleaning performance of the substrate while suppressing the destruction of the device pattern of the substrate.

  The substrate cleaning apparatus of the present invention includes a holding unit for holding a substrate, a cleaning liquid supply unit for supplying a cleaning liquid to the surface of the substrate held by the holding unit, and forming a liquid film of the cleaning liquid on the surface of the substrate; A convection generating mechanism for generating convection in the liquid film of the cleaning liquid by generating portions having different temperatures in the liquid film of the cleaning liquid formed on the surface of the substrate by the cleaning liquid supply unit; and a liquid film of the cleaning liquid And a liquid supply unit that supplies a liquid that gives a physical force to the liquid crystal.

  In the substrate cleaning apparatus of the present invention, the convection generating mechanism is configured such that the cleaning liquid liquid formed on the surface of the substrate by the cleaning liquid supply unit is formed on the surface of the liquid film of the cleaning liquid on the substrate held by the holding unit. It may be a temperature adjusting nozzle that supplies a liquid or gas having a temperature different from that of the film.

  In this case, the temperature of the liquid or gas supplied to the surface of the cleaning liquid film on the substrate by the temperature adjusting nozzle is higher than the temperature of the cleaning liquid film formed on the surface of the substrate by the cleaning liquid supply unit. It may be.

  Alternatively, the temperature of the liquid or gas supplied to the surface of the cleaning liquid film on the substrate by the temperature adjusting nozzle is lower than the temperature of the cleaning liquid film formed on the surface of the substrate by the cleaning liquid supply unit. May be.

  In the substrate cleaning apparatus of the present invention, the convection generating mechanism is a heating mechanism that generates a convection in the cleaning liquid film by heating the cleaning liquid film formed on the surface of the substrate by the cleaning liquid supply unit. May be.

  Alternatively, the convection generating mechanism may be a cooling mechanism that cools the liquid film of the cleaning liquid formed on the surface of the substrate by the cleaning liquid supply unit and causes convection in the liquid film of the cleaning liquid.

  In the substrate cleaning apparatus of the present invention, the liquid supply unit is a two-fluid nozzle that generates cleaning liquid droplets by mixing a cleaning liquid and a gas, and ejects the cleaning liquid droplets onto the cleaning liquid film. There may be.

  In this case, the convection generating mechanism is supplied to the two-fluid nozzle so that the droplet of the cleaning liquid ejected from the two-fluid nozzle has a temperature different from that of the liquid film of the cleaning liquid formed on the surface of the substrate. A cleaning liquid temperature adjusting unit that adjusts the temperature of the cleaning liquid may be used.

  Alternatively, the convection generating mechanism may be configured such that the gas supplied to the two-fluid nozzle is such that a droplet of the cleaning liquid ejected from the two-fluid nozzle has a temperature different from that of the liquid film of the cleaning liquid formed on the surface of the substrate. It may be a gas temperature adjusting unit that adjusts the temperature.

  The substrate cleaning method of the present invention includes a step of holding a substrate by a holding unit, a step of forming a liquid film of cleaning liquid on the surface of the substrate held by the holding unit, and a liquid film of cleaning liquid formed on the surface of the substrate. A step of generating convection in the liquid film of the cleaning liquid by generating portions having different temperatures in the inside, and a step of supplying a liquid that gives physical force to the liquid film of the cleaning liquid And

  In the substrate cleaning method of the present invention, when the convection is generated in the liquid film of the cleaning liquid, the liquid film of the cleaning liquid formed on the surface of the substrate with respect to the surface of the liquid film of the cleaning liquid formed on the surface of the substrate You may supply the liquid or gas of the temperature different from.

  In this case, when convection is generated in the liquid film of the cleaning liquid, the temperature of the liquid or gas supplied to the surface of the liquid film of the cleaning liquid formed on the surface of the substrate is the liquid temperature of the cleaning liquid formed on the surface of the substrate. It may be higher than the temperature of the film.

  Alternatively, when convection is generated in the liquid film of the cleaning liquid, the temperature of the liquid or gas supplied to the surface of the liquid film of the cleaning liquid formed on the surface of the substrate is the liquid film of the cleaning liquid formed on the surface of the substrate. The temperature may be lower.

  In the substrate cleaning method of the present invention, when the convection is generated in the liquid film of the cleaning liquid, the liquid film of the cleaning liquid formed on the surface of the substrate may be heated by a heating mechanism.

  Alternatively, when the convection is generated in the liquid film of the cleaning liquid, the liquid film of the cleaning liquid formed on the surface of the substrate may be cooled by a cooling mechanism.

  In the substrate cleaning method of the present invention, when supplying a liquid that gives physical force to the liquid film of the cleaning liquid, the cleaning liquid and the gas are mixed in the two-fluid nozzle to generate cleaning liquid droplets, A droplet of the cleaning liquid may be ejected from the two-fluid nozzle to the liquid film.

  In this case, when the convection is generated in the liquid film of the cleaning liquid, the liquid droplets of the cleaning liquid ejected from the two-fluid nozzle have a temperature different from that of the liquid film of the cleaning liquid formed on the surface of the substrate. The temperature of the cleaning liquid supplied to the two-fluid nozzle may be adjusted.

  Alternatively, when the convection is generated in the cleaning liquid film, the cleaning liquid droplets ejected from the two-fluid nozzle have a temperature different from that of the cleaning liquid film formed on the surface of the substrate. The temperature of the gas supplied to the fluid nozzle may be adjusted.

  According to the substrate cleaning apparatus and the substrate cleaning method of the present invention, particles attached to the surface of the substrate can be sufficiently removed even when the physical force of the liquid supplied to the substrate is small. The cleaning performance for the substrate can be improved while suppressing the destruction of the pattern.

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 figure which expands and shows a state when the droplet of a cleaning liquid is sprayed on a wafer. It is a schematic block diagram which shows the other structure of the board | substrate cleaning apparatus in this invention. It is a schematic block diagram which shows other structure of the board | substrate cleaning apparatus in this invention. It is a figure which expands and shows the state when the droplet of the washing | cleaning liquid is sprayed on a wafer in the conventional wafer cleaning method.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 3 are views showing an embodiment of a substrate cleaning apparatus and a substrate cleaning method according to the present invention. 1 is a schematic configuration diagram showing the configuration of the substrate cleaning apparatus in the present embodiment, and FIG. 2 is a longitudinal sectional view showing details of the configuration of the two-fluid nozzle in the substrate cleaning apparatus shown in FIG. is there. FIG. 3 is an enlarged view showing a state when droplets of the cleaning liquid are ejected onto the wafer.

  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 temperature adjustment 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 the cleaning liquid to the surface of the wafer W held by the spin chuck 12 and forms a liquid film of the cleaning liquid on the surface of the wafer W. The two-fluid nozzle 30 ejects droplets of the cleaning liquid onto the surface of the liquid film of the cleaning liquid formed on the surface of the wafer W to remove particles and the like attached to the surface of the wafer W. The temperature adjustment nozzle 40 supplies a cleaning liquid having a temperature higher than that of the cleaning liquid film to the surface of the cleaning liquid film formed on the surface of the wafer W. 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 described above, the rinse nozzle 20 supplies a cleaning liquid to the surface of the wafer W held by the spin chuck 12 and constitutes a cleaning liquid supply unit for forming a liquid film of the cleaning liquid on the surface of the wafer W. It has become.

  As shown in FIG. 1, the two-fluid nozzle 30 and the temperature adjustment nozzle 40 are each attached to an arm 48. The arm 48 to which the two-fluid nozzle 30 and the temperature adjustment nozzle 40 are attached is connected to the rotary 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 temperature adjustment nozzle 40 from the upper position near the center of the wafer W to the periphery of the wafer W. It is made to reciprocate along a horizontal plane within the range to the position outside the part. The arm drive mechanism can also reciprocate the rotary shaft portion 46 in the vertical direction.

  In the embodiment of the substrate cleaning apparatus 1 shown in FIG. 1, the example in which the two-fluid nozzle 30 and the temperature adjustment nozzle 40 are attached to the common arm 48 has been described, but the two-fluid nozzle 30 and the temperature adjustment nozzle 40 are different from each other. It may be adapted to be attached to the arm. In this case, the two-fluid nozzle 30 and the temperature adjustment nozzle 40 can be moved independently of each other.

  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, the cleaning liquid supply pipe 34 is provided with a cleaning liquid temperature adjusting section 34 b that adjusts the temperature of the cleaning liquid passing through the cleaning liquid supply pipe 34. The temperature of the cleaning liquid sent to the two-fluid nozzle 30 can be adjusted by such a cleaning liquid temperature adjusting unit 34b, and thereby the temperature of the droplet of the cleaning liquid ejected from the two-fluid nozzle 30 can be adjusted. .

  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 of the valve 36a and changing the pressure (flow rate) of nitrogen gas sent to the two-fluid nozzle 30, the particle size of the droplets of the cleaning liquid generated in the two-fluid nozzle 30 can be changed. It has become. The nitrogen gas supply pipe 36 is provided with a gas temperature adjusting unit 36b for adjusting the temperature of the nitrogen gas passing through the nitrogen gas supply pipe 36. The temperature of the nitrogen gas sent to the two-fluid nozzle 30 can be adjusted by such a gas temperature adjusting unit 36b, and thereby the temperature of the droplet of the cleaning liquid ejected from the two-fluid nozzle 30 can be adjusted. it can.

  The configuration of the two-fluid nozzle 30 will be specifically described with reference to FIG. FIG. 2 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. 2, 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.

  The configuration of the two-fluid nozzle 30 will be described in more detail. The two-fluid nozzle 30 has a substantially cylindrical nozzle body 30a made of, for example, a fluororesin, and a cleaning liquid supply is provided inside the nozzle body 30a. A cleaning liquid flow path 30 b that communicates with the pipe 34 and a nitrogen gas flow path 30 c that communicates 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 cleaning liquid supply pipe 44 is connected to the temperature adjustment nozzle 40, and the cleaning liquid is supplied to the temperature adjustment nozzle 40 through the cleaning liquid supply pipe 44. A cleaning liquid tank 42 is provided at the upstream end of the cleaning liquid supply pipe 44, and a high temperature cleaning liquid is stored in the cleaning liquid tank 42. More specifically, the temperature of the cleaning liquid stored in the cleaning liquid tank 42 is higher than the temperature of the cleaning liquid stored in the cleaning liquid tank 22. A high-temperature cleaning liquid is sent from the cleaning liquid tank 42 to the cleaning liquid supply pipe 44 by a pumping means (not shown) such as a pump, and the high-temperature cleaning liquid is sent from the cleaning liquid supply pipe 44 to the temperature adjustment nozzle 40. The cleaning liquid supply pipe 44 is provided with a valve 44a capable of adjusting the opening degree. In this way, the temperature adjustment nozzle 40 has a cleaning liquid film surface on the wafer W held by the spin chuck 12, and the cleaning liquid film formed on the surface of the wafer W by the rinse nozzle 20. A hot cleaning solution is supplied.

  Instead of storing the high temperature cleaning liquid in the cleaning liquid tank 42, the cleaning liquid tank 42 stores cleaning liquid having substantially the same temperature as the cleaning liquid stored in the cleaning liquid tank 22, and the cleaning liquid supply pipe 44 is heated by a heater or the like. A mechanism (not shown) may be provided. Even in this case, when the cleaning liquid passes through the cleaning liquid supply pipe 44, the cleaning liquid is heated by the heating mechanism provided in the cleaning liquid supply pipe 44, so that the high-temperature cleaning liquid is sent to the temperature adjustment nozzle 40. As a result, the temperature adjustment nozzle 40 is higher in temperature than the cleaning liquid film formed on the surface of the wafer W by the rinse nozzle 20 with respect to the surface of the cleaning liquid film on the wafer W held by the spin chuck 12. The cleaning liquid is supplied.

  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 from the rinse nozzle 20 to the surface of the wafer W held by the spin chuck 12 and rotating in the chamber 10, and a liquid film of the cleaning liquid is formed on the surface of the wafer W.

  After a cleaning liquid film is formed on the surface of the rotating wafer W held by the spin chuck 12, cleaning liquid droplets are ejected by the two-fluid nozzle 30 onto the surface of the cleaning liquid film on the wafer W. At the same time, a high-temperature cleaning liquid is supplied by the temperature adjustment nozzle 40. Here, since the cleaning liquid having a temperature higher than that of the liquid film of the cleaning liquid is supplied to the surface of the liquid film of the cleaning liquid on the wafer W by the temperature adjustment nozzle 40, the temperature difference portion (specifically, in the liquid film of the cleaning liquid) Specifically, a portion having a high temperature) is generated, and convection is generated in the liquid film of the cleaning liquid. This will be described in detail with reference to FIG. FIG. 3 is an enlarged view showing a state when the droplet D of the cleaning liquid is sprayed onto the surface of the liquid film C of the cleaning liquid on the wafer W by the two-fluid nozzle 30.

  As shown in FIG. 3, a cleaning liquid having a higher temperature than the liquid film C of the cleaning liquid is supplied to the surface of the liquid film C of the cleaning liquid on the wafer W by the temperature adjustment nozzle 40, thereby cleaning the liquid film of the cleaning liquid. In C, a portion having a different temperature (specifically, a portion having a high temperature) is generated, and convection occurs as shown by an arrow in the liquid film C of the cleaning liquid in FIG. When convection occurs between the boundary layer in the liquid film C of the cleaning liquid and the region above the boundary layer, a liquid flow is also caused in the boundary layer, and the boundary layer B as shown in FIG. It will be resolved. In this manner, in the present embodiment, the temperature adjustment nozzle 40 generates a portion having a different temperature in the liquid film C of the cleaning liquid formed on the surface of the wafer W, thereby forming the liquid film C of the cleaning liquid. A convection generating mechanism for generating convection is configured.

  Then, in a state in which the boundary layer B as shown in FIG. 6 is eliminated, the cleaning fluid droplet D is ejected by the two-fluid nozzle 30 onto the surface of the cleaning solution liquid film C on the wafer W. The particles P adhering to the wafer W are removed. Here, the physical force of the droplet D of the cleaning liquid ejected from the two-fluid nozzle 30 onto the surface of the liquid film C of the cleaning liquid on the wafer W is the device pattern W1 (hereinafter also referred to as pattern W1) of the wafer W. It is set to a size that will not destroy it. Actually, the timing at which the cleaning fluid droplet D is jetted by the two-fluid nozzle 30 onto the surface of the cleaning liquid film C on the wafer W is relative to the surface of the cleaning liquid film C on the wafer W. Alternatively, the temperature adjustment nozzle 40 may supply the high temperature cleaning liquid and the timing at which convection is generated in the liquid film C of the cleaning liquid.

  Thereafter, the rinse nozzle 20, the two-fluid nozzle 30 and the temperature adjustment 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, portions having different temperatures (specifically, portions having high temperatures) are generated in the liquid film of the cleaning liquid formed on the surface of the wafer W. Is provided with a temperature adjustment nozzle 40 for generating convection in the liquid film of the cleaning liquid. Specifically, the temperature adjustment nozzle 40 has a temperature different from that of the cleaning liquid film formed on the surface of the wafer W relative to the surface of the cleaning liquid film on the wafer W held by the spin chuck 12. (Specifically, the cleaning liquid having a higher temperature than the liquid film of the cleaning liquid) is supplied. As described above, the temperature adjustment nozzle 40 causes convection between the boundary layer in the liquid film of the cleaning liquid formed on the surface of the wafer W and the region above the boundary layer, and the flow of the liquid also in the boundary layer. Can cause the boundary layer to be eliminated. At this time, since a liquid flow is also generated on the surface of the wafer W where the particles are present, a force for separating the particles from the wafer W is generated. For this reason, in order to suppress the destruction of the pattern of the wafer W, the speed of the droplet of the cleaning liquid sprayed onto the wafer W by the two-fluid nozzle 30 is reduced, or the size of the droplet of the cleaning liquid is reduced. Even if the physical force exerted on the surface of the wafer W by the droplets of the cleaning liquid is weakened, the particles existing on the wafer W can be separated from the surface of the wafer W. As described above, according to the substrate cleaning apparatus 1 of the present embodiment, the convection is generated in the liquid film of the cleaning liquid formed on the surface of the wafer W, and the flow of the liquid is also generated in the boundary layer. A liquid flow is also generated on the surface of W, particles and the like adhering to the surface of the wafer W can be sufficiently removed, the destruction of the pattern of the wafer W is suppressed, and the cleaning performance for the wafer W is improved. Can do.

  Further, according to the substrate cleaning method of the present embodiment, the cleaning liquid is generated by generating portions having different temperatures (specifically, portions having higher temperatures) in the liquid film of the cleaning liquid formed on the surface of the wafer W. Convection is generated in the liquid film, and a droplet of the cleaning liquid is ejected from the two-fluid nozzle 30 to the liquid film of the cleaning liquid in which the convection has occurred. According to such a substrate cleaning method, convection is generated between the boundary layer in the liquid film of the cleaning liquid formed on the surface of the wafer W and the region above the boundary layer, and the liquid flow also in the boundary layer. Can cause the boundary layer to be eliminated. At this time, since a liquid flow is also generated on the surface of the wafer W where the particles are present, a force for separating the particles from the wafer W is generated. For this reason, in order to prevent the pattern of the wafer W from being destroyed, the speed of the cleaning liquid droplets sprayed onto the wafer W is reduced, or the size of the cleaning liquid droplets is reduced. Even if the physical force exerted on the surface of the wafer W by the droplet is weakened, the particles existing on the wafer W can be separated from the surface of the wafer W. As described above, according to the substrate cleaning method of the present embodiment, convection is generated in the liquid film of the cleaning liquid formed on the surface of the wafer W, and the flow of the liquid is also generated in the boundary layer. A liquid flow is also generated on the surface of the wafer, and particles adhering to the surface of the wafer W can be sufficiently removed, thereby preventing damage to the pattern of the wafer W and improving the cleaning performance for the wafer W. it can.

  In the substrate cleaning apparatus 1 and the substrate cleaning method of the present embodiment, layers having different temperatures are formed in the liquid film of the cleaning liquid on the wafer W. It is more preferable that the temperature on the side (contact portion with the surface of the wafer W) is higher. That is, since the convection generated in the liquid film of the cleaning liquid moves from the higher temperature to the lower temperature, when the temperature below the liquid film of the cleaning liquid on the wafer W is high, the convection moves from the bottom to the top. Such a convection becomes more effective as a force for moving particles on the wafer W.

  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, instead of supplying a cleaning liquid having a temperature different from that of the liquid film of the cleaning liquid from the temperature adjustment nozzle 40 to the surface of the liquid film of the cleaning liquid on the wafer W, the inside of the liquid film of the cleaning liquid is supplied by the two-fluid nozzle 30. Convection may be generated in the. More specifically, droplets of the cleaning liquid having a temperature different from the cleaning liquid film formed on the surface of the wafer W by the rinse nozzle 20 are jetted onto the cleaning liquid film on the wafer W by the two-fluid nozzle 30. As a result, convection occurs in the liquid film of the cleaning liquid. In this case, the temperature of the cleaning liquid supplied to the two-fluid nozzle 30 is adjusted by the cleaning liquid temperature adjusting section 34 b provided in the cleaning liquid supply pipe 34, or the gas temperature adjusting section provided in the nitrogen gas supply pipe 36. By adjusting the temperature of the nitrogen gas supplied to the two-fluid nozzle 30 by 36b, the temperature of the liquid droplet of the cleaning liquid ejected from the two-fluid nozzle 30 is changed to the liquid film of the cleaning liquid formed on the surface of the wafer W. Be different from temperature. In this modification, convection is generated in the liquid film of the cleaning liquid on the wafer W by the cleaning liquid temperature adjusting section 34 b provided in the cleaning liquid supply pipe 34 and the gas temperature adjusting section 36 b provided in the nitrogen gas supply pipe 36. A convection generating mechanism is configured.

  When droplets of a cleaning liquid having a temperature different from that of the cleaning liquid film on the wafer W are jetted onto the cleaning liquid film on the wafer W by the two-fluid nozzle 30 to cause convection in the cleaning liquid film. In the liquid film of the cleaning liquid on the wafer W, convection occurs at a position where the cleaning liquid droplets are ejected from the two-fluid nozzle 30, and the liquid having a different temperature due to the ejected cleaning liquid droplets is transferred to the wafer W. As a result of the rotation, the flow to the peripheral edge of the wafer W spreads a portion of different temperature over the entire liquid film of the cleaning liquid on the wafer W, and convection with the boundary layer in the liquid film of the cleaning liquid occurs. . Then, a liquid (cleaning liquid droplets) that gives physical force is supplied from the two-fluid nozzle 30 to the liquid film of the cleaning liquid in which the boundary layer has been eliminated due to convection, whereby particles and the like are removed from the wafer W. Become so.

  As another modification, the temperature adjustment nozzle 40 may supply liquid other than the cleaning liquid to the surface of the liquid film of the cleaning liquid on the wafer W held by the spin chuck 12. . Further, the temperature adjustment nozzle 40 does not supply a high-temperature liquid to the surface of the liquid film of the cleaning liquid on the wafer W held by the spin chuck 12, but a high-temperature gas (specifically, for example, a high-temperature gas) Nitrogen gas or the like) may be supplied. Even in this case, since the convection can be generated in the liquid film of the cleaning liquid formed on the surface of the wafer W, the boundary layer can be eliminated by causing the flow of the liquid also in the boundary layer. At this time, since a liquid flow is also generated on the surface of the wafer W where the particles are present, a force for separating the particles from the wafer W is generated.

  Further, in the substrate cleaning apparatus and the substrate cleaning method according to the present invention, the temperature adjustment nozzle 40 is configured such that the cleaning liquid on the wafer W is applied to the surface of the cleaning liquid on the wafer W held by the spin chuck 12. A liquid or gas having a temperature lower than that of the membrane may be supplied. In this case, a liquid or gas having a lower temperature than the liquid film of the cleaning liquid on the wafer W is supplied to the surface of the liquid film of the cleaning liquid on the wafer W held by the spin chuck 12. A portion having a low temperature is generated in the liquid film of the cleaning liquid. Even in this case, convection is generated in the liquid film of the cleaning liquid as in the case where a portion having a high temperature is generated in the liquid film of the cleaning liquid. As a result, a liquid flow is also generated on the surface of the wafer W where the particles are present, so that a force for separating the particles from the wafer W is generated.

  In the substrate cleaning apparatus and the substrate cleaning method according to the present invention, instead of using the temperature adjustment nozzle 40 as a convection generating mechanism for generating convection in the cleaning liquid film, the cleaning liquid film on the wafer W is directly used. A heating mechanism for heating or a cooling mechanism for directly cooling the liquid film of the cleaning liquid may be used. Hereinafter, an example in which the above-described heating mechanism or cooling mechanism is applied as the convection generating mechanism will be described with reference to FIGS. 4 and 5.

  As shown in FIG. 4, the substrate cleaning apparatus 1a having another configuration according to the present invention is provided with a temperature adjustment nozzle 40, a cleaning liquid tank 42, a cleaning liquid supply pipe 44, etc., as compared with the substrate cleaning apparatus 1 shown in FIG. Instead, a heating mechanism 60 for heating the liquid film of the cleaning liquid formed on the surface of the wafer W is provided. In the substrate cleaning apparatus 1a shown in FIG. 4, the same constituent elements as those of the substrate cleaning apparatus 1 shown in FIG. Hereinafter, the configuration of the substrate cleaning apparatus 1a will be described in detail.

  In the substrate cleaning apparatus 1 a as shown in FIG. 4, the heating mechanism 60 is provided slightly above the wafer W held by the spin chuck 12. The heating mechanism 60 heats the liquid film of the cleaning liquid formed on the surface of the wafer W by the rinse nozzle 20 to cause convection in the liquid film of the cleaning liquid. That is, after a liquid film of the cleaning liquid is formed on the surface of the wafer W held and rotated by the spin chuck 12, droplets of the cleaning liquid are ejected by the two-fluid nozzle 30 onto the liquid film of the cleaning liquid on the wafer W. At the same time, the liquid film of the cleaning liquid formed on the surface of the wafer W is heated by the heating mechanism 60. Here, when the liquid film of the cleaning liquid is heated, a portion having a different temperature (specifically, a portion having a high temperature) is generated in the liquid film of the cleaning liquid, and convection is generated in the liquid film of the cleaning liquid. It becomes. When convection occurs between the boundary layer in the liquid film of the cleaning liquid and the region above the boundary layer, a liquid flow is also caused in the boundary layer, and the boundary layer B as shown in FIG. 6 is eliminated. Is done. As described above, in the substrate cleaning apparatus 1a as shown in FIG. 4, the heating mechanism 60 has a portion with a different temperature (specifically, a portion with a high temperature) in the liquid film of the cleaning liquid formed on the surface of the wafer W. ) To form a convection generating mechanism for generating convection in the liquid film of the cleaning liquid.

  Then, in the state where the boundary layer B as shown in FIG. 6 is eliminated, the droplets of the cleaning liquid are ejected by the two-fluid nozzle 30 onto the surface of the liquid film of the cleaning liquid on the wafer W. Particles adhering to are removed.

  As described above, according to the substrate cleaning apparatus 1a as shown in FIG. 4, since the heating mechanism 60 is provided as a convection generating mechanism, the boundary layer in the liquid film of the cleaning liquid formed on the surface of the wafer W The boundary layer can be eliminated by causing convection between the region above the boundary layer and causing a liquid flow in the boundary layer. At this time, since a liquid flow is also generated on the surface of the wafer W where the particles are present, a force for separating the particles from the wafer W is generated. For this reason, in order to suppress the destruction of the pattern of the wafer W, the speed of the droplet of the cleaning liquid sprayed onto the wafer W by the two-fluid nozzle 30 is reduced, or the size of the droplet of the cleaning liquid is reduced. Even if the physical force exerted on the surface of the wafer W by the droplets of the cleaning liquid is weakened, the particles existing on the wafer W can be separated from the surface of the wafer W. Thus, according to the substrate cleaning apparatus 1a as shown in FIG. 4, by causing convection in the liquid film of the cleaning liquid formed on the surface of the wafer W and causing the flow of liquid in the boundary layer, A liquid flow is also generated on the surface of the wafer W, particles and the like adhering to the surface of the wafer W can be sufficiently removed, and the destruction of the pattern of the wafer W is suppressed and the cleaning performance for the wafer W is improved. be able to.

  In the configuration of the substrate cleaning apparatus 1 a shown in FIG. 4, the example in which the heating mechanism 60 is provided separately from the spin chuck 12 has been described. However, even if the heating mechanism 60 is built in the spin chuck 12. Good. Even in this case, the heating mechanism 60 heats the liquid film of the cleaning liquid on the wafer W held by the spin chuck 12, and convection can be generated in the liquid film of the cleaning liquid.

  Further, in the substrate cleaning apparatus 1b of still another configuration according to the present invention as shown in FIG. 5, the temperature adjustment nozzle 40, the cleaning liquid tank 42, and the cleaning liquid supply pipe 44 are compared with the substrate cleaning apparatus 1 shown in FIG. And a cooling mechanism 70 for cooling the liquid film of the cleaning liquid formed on the surface of the wafer W is provided instead. In the substrate cleaning apparatus 1b shown in FIG. 5, the same components as those in the substrate cleaning apparatus 1 shown in FIG. Hereinafter, the configuration of such a substrate cleaning apparatus 1b will be described in detail.

  In the substrate cleaning apparatus 1 b as shown in FIG. 5, the cooling mechanism 70 is provided slightly above the wafer W held by the spin chuck 12. The cooling mechanism 70 cools the cleaning liquid film formed on the surface of the wafer W by the rinse nozzle 20 to cause convection in the cleaning liquid film. That is, after a liquid film of the cleaning liquid is formed on the surface of the wafer W held and rotated by the spin chuck 12, droplets of the cleaning liquid are ejected by the two-fluid nozzle 30 onto the liquid film of the cleaning liquid on the wafer W. At the same time, the liquid film of the cleaning liquid formed on the surface of the wafer W is cooled by the cooling mechanism 70. Here, when the liquid film of the cleaning liquid is cooled, portions having different temperatures (specifically, portions having low temperatures) are generated in the liquid film of the cleaning liquid, and convection is generated in the liquid film of the cleaning liquid. It becomes. When convection occurs between the boundary layer in the liquid film of the cleaning liquid and the region above the boundary layer, a liquid flow is also caused in the boundary layer, and the boundary layer B as shown in FIG. 6 is eliminated. Is done. As described above, in the substrate cleaning apparatus 1b as shown in FIG. 5, the cooling mechanism 70 is provided with a portion having a different temperature (specifically, a portion having a low temperature) in the liquid film of the cleaning liquid formed on the surface of the wafer W. ) To form a convection generating mechanism for generating convection in the liquid film of the cleaning liquid.

  Then, in the state where the boundary layer B as shown in FIG. 6 is eliminated, the droplets of the cleaning liquid are ejected by the two-fluid nozzle 30 onto the surface of the liquid film of the cleaning liquid on the wafer W. Particles adhering to are removed.

  As described above, according to the substrate cleaning apparatus 1b as shown in FIG. 5, since the cooling mechanism 70 is provided as a convection generating mechanism, the boundary layer in the liquid film of the cleaning liquid formed on the surface of the wafer W The boundary layer can be eliminated by causing convection between the region above the boundary layer and causing a liquid flow in the boundary layer. At this time, since a liquid flow is also generated on the surface of the wafer W where the particles are present, a force for separating the particles from the wafer W is generated. For this reason, in order to suppress the destruction of the pattern of the wafer W, the speed of the droplet of the cleaning liquid sprayed onto the wafer W by the two-fluid nozzle 30 is reduced, or the size of the droplet of the cleaning liquid is reduced. Even if the physical force exerted on the surface of the wafer W by the droplets of the cleaning liquid is weakened, the particles existing on the wafer W can be separated from the surface of the wafer W. As described above, according to the substrate cleaning apparatus 1b as shown in FIG. 5, by causing convection in the liquid film of the cleaning liquid formed on the surface of the wafer W and causing the liquid flow in the boundary layer, A liquid flow is also generated on the surface of the wafer W, particles and the like adhering to the surface of the wafer W can be sufficiently removed, and the destruction of the pattern of the wafer W is suppressed and the cleaning performance for the wafer W is improved. be able to.

  In the configuration of the substrate cleaning apparatus 1b shown in FIG. 5, the example in which the cooling mechanism 70 is provided separately from the spin chuck 12 has been described, but the cooling mechanism 70 may be built in the spin chuck 12. Good. Even in this case, the cooling mechanism 70 cools the liquid film of the cleaning liquid on the wafer W held by the spin chuck 12, and convection can be generated in the liquid film of the cleaning liquid.

  In the substrate cleaning apparatus and the substrate cleaning method according to the present invention, a liquid supply unit that supplies a liquid that gives a physical force to the liquid film of the cleaning liquid on the wafer W can be used other than the two-fluid nozzle. . Specifically, a single fluid spray or an ultrasonic nozzle may be used as a liquid supply unit that supplies a liquid that gives a physical force to the liquid film of the cleaning liquid on the wafer W. Thus, in the substrate cleaning apparatus and the substrate cleaning method according to the present invention, the spin chuck 12 serves as a liquid supply unit that supplies a liquid that gives physical force to the liquid film of the cleaning liquid that has been convected by the convection generating mechanism. As long as it is of a type that is not in contact with the held wafer W, it is not limited to the two-fluid nozzle, and various types can be used.

1, 1a, 1b Substrate cleaning device 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 30 Two-fluid nozzle 30a Nozzle body 30b Cleaning liquid flow path 30c Nitrogen gas flow path 30d Merge point 31 Jetting range of cleaning liquid droplets 32 Cleaning liquid tank 34 Cleaning liquid supply pipe 34a Valve 34b Cleaning liquid temperature adjustment section 36 Nitrogen gas supply pipe 36a Valve 36b Gas temperature adjustment section 38 Nitrogen gas supply mechanism 40 Temperature adjustment nozzle 42 Cleaning liquid tank 44 Cleaning liquid supply pipe 46 Rotating shaft 48 Arm 50 Cleaning liquid discharge pipe 60 Heating mechanism 70 Cooling mechanism W Wafer W1 Device pattern C Cleaning liquid film D Cleaning liquid droplet P Particle B Boundary layer

Claims (10)

A holding unit for holding the substrate;
A cleaning liquid supply unit for supplying a cleaning liquid to the surface of the substrate held by the holding unit, and forming a liquid film of the cleaning liquid on the surface of the substrate;
In the liquid film of the cleaning liquid formed on the surface of the substrate by the cleaning liquid supply unit, a convection generating mechanism that generates convection in the liquid film of the cleaning liquid by generating portions having different temperatures,
A liquid supply unit that supplies a liquid that gives physical force to the liquid film of the cleaning liquid;
Equipped with a,
The convection generating mechanism includes a temperature adjusting nozzle,
The temperature adjustment nozzle supplies the same cleaning liquid having a temperature different from that of the cleaning liquid film formed on the surface of the substrate by the cleaning liquid supply unit, to the surface of the cleaning liquid film on the substrate held by the holding unit. In the liquid film of the cleaning liquid on the substrate, convection is generated in the liquid film of the cleaning liquid by generating portions having different temperatures.
The substrate cleaning apparatus, wherein the temperature adjustment nozzle and the liquid supply unit are movable in a range from an upper position near the center of the substrate to an outer position of the peripheral edge of the substrate. It said temperature adjusting nozzle and the liquid supply portion is provided on a common arm, while at the same time causing a convection in the liquid film by the supply of the cleaning liquid of the temperature adjusting nozzle, Rukoto to supply liquid by the liquid supply portion The substrate cleaning apparatus according to claim 1. Characterized in that it is the temperature of the liquid supplied to the surface of the cleaning liquid of the liquid film on the substrate is higher than the temperature of the cleaning liquid of the liquid film formed on the surface of the substrate by the cleaning liquid supply section by the temperature adjusting nozzle The substrate cleaning apparatus according to claim 1 or 2. Characterized in that it is the temperature of the liquid supplied to the surface of the cleaning liquid of the liquid film on the substrate is lower than the temperature of the cleaning liquid of the liquid film formed on the surface of the substrate by the cleaning liquid supply section by the temperature adjusting nozzle The substrate cleaning apparatus according to claim 1 or 2. The liquid supply portion, claim by mixing the cleaning liquid and the gas to produce droplets of the cleaning liquid, characterized in that it is a two-fluid nozzle which ejects droplets of the cleaning liquid to the liquid film of the cleaning liquid 1 The substrate cleaning apparatus according to any one of claims 1 to 4 . A step of holding the substrate by the holding unit;
Forming a liquid film of a cleaning solution on the surface of the substrate held by the holding unit;
Generating convection in the liquid film of the cleaning liquid by generating portions having different temperatures in the liquid film of the cleaning liquid formed on the surface of the substrate by the temperature adjustment nozzle ;
Supplying a liquid that gives physical force to the liquid film of the cleaning liquid by a liquid supply unit ;
Equipped with a,
In the step of generating the convection, the liquid film of the cleaning liquid formed on the surface of the substrate by the cleaning liquid supply unit with respect to the surface of the liquid film of the cleaning liquid on the substrate held by the holding unit by the temperature adjustment nozzle By supplying the same cleaning liquid having a different temperature from that in the liquid film of the cleaning liquid on the substrate, a portion having a different temperature is generated to cause convection in the liquid film of the cleaning liquid, and the temperature adjusting nozzle is In the step of supplying the liquid that gives the physical force by moving in a range from an upper position in the vicinity of the center of the substrate to an outer position of the peripheral edge of the substrate, the liquid supply unit is positioned in the vicinity of the center of the substrate. The substrate cleaning method is characterized in that the substrate is moved in a range from a position above the substrate to a position outside the peripheral edge of the substrate. The temperature adjustment nozzle and the liquid supply unit are provided on a common arm, and supply of the liquid by the liquid supply unit is performed at the same time as convection is generated in the liquid film by supplying the cleaning liquid of the temperature adjustment nozzle. The substrate cleaning method according to claim 6, wherein: When the convection is generated in the cleaning liquid film, the temperature of the liquid supplied to the surface of the cleaning liquid film formed on the surface of the substrate is higher than the temperature of the cleaning liquid film formed on the surface of the substrate. The substrate cleaning method according to claim 6, wherein the substrate cleaning method is high. When the convection is generated in the cleaning liquid film, the temperature of the liquid supplied to the surface of the cleaning liquid film formed on the surface of the substrate is higher than the temperature of the cleaning liquid film formed on the surface of the substrate. The substrate cleaning method according to claim 6, wherein the substrate cleaning method is low. 7. The liquid supply unit is a two-fluid nozzle that mixes a cleaning liquid and a gas to generate cleaning liquid droplets and ejects the cleaning liquid droplets onto the cleaning liquid film. The substrate cleaning method according to claim 1.

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