JP2009152290A - Apparatus for cleaning substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for cleaning a substrate that changes the central position of a vortex formed by supercritical fluid in a space for cleaning a substrate. <P>SOLUTION: An apparatus 10 for cleaning a substrate includes a chamber 20 for cleaning a substrate having a space S for cleaning a substrate. The chamber 20 for cleaning a substrate has a plurality of fluid delivery portions 21 provided at intervals along an inner wall 25 defining the cleaning space S and delivering supercritical fluid into the cleaning space S at a predetermined angle α for the inner wall 25, and channels 22 for distributing the supercritical fluid supplied externally to the plurality of fluid delivery portions 21. The distribution channel 22 is divided into a plurality of partial channels 22a and each partial channel 22a is supplied with the supercritical fluid externally and connected with the fluid delivery portion 21. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate cleaning apparatus that performs cleaning of a substrate surface such as a semiconductor substrate or a glass substrate for flat panel display, a resist stripping process, and the like using a supercritical fluid.

  In a manufacturing process of a glass substrate for a semiconductor manufacturing apparatus or a flat panel display (FPD), there is a lithography process for forming a circuit pattern on a semiconductor substrate (semiconductor wafer) or a glass substrate as an object to be cleaned. In this lithography process, a resist is applied to a substrate (object to be cleaned), light is irradiated to the resist through a mask on which a circuit pattern is formed, and a portion of the resist not irradiated with light (or light is irradiated). The circuit pattern is transferred to the substrate by repeating a series of steps of removing the removed portion and performing processing such as development, peeling or etching on the removed portion.

  In each step in this series of steps, if the semiconductor substrate or the glass substrate is contaminated, it becomes impossible to form a circuit pattern precisely, resulting in generation of defective products. Therefore, in the process of forming the circuit pattern, the semiconductor substrate and the glass substrate are cleaned so that the substrate surface is in a clean state in which fine particles (particles) such as resist and dust are not left.

  Conventionally, as a method for cleaning the substrate, a so-called wet method of cleaning the substrate surface using a liquid such as water or a cleaning liquid has been employed. However, in recent years, with the miniaturization of circuit pattern sizes, there has been a problem that the circuit pattern formed on the substrate collapses due to the surface tension of the liquid used for cleaning (pattern collapse) in the wet cleaning. Therefore, in recent years, a cleaning method using a supercritical fluid has been adopted for cleaning the substrate.

  As a substrate cleaning apparatus using this supercritical fluid, a supercritical fluid to which a cleaning agent is added is allowed to flow along the surface (cleaning surface) of the substrate without causing pattern collapse of a fine circuit pattern. An apparatus for cleaning the substrate surface is known.

  In such a substrate cleaning apparatus, the flow of the supercritical fluid may vortex on the substrate. In this case, in the vicinity of the vortex center, the flow becomes slower than the supercritical fluid at other positions, and thus processing unevenness may occur in the resist stripping process. In addition, when the vortex of the supercritical fluid is formed at a certain position, there is a concern that defects such as scratches on the substrate surface may occur due to the concentration of the washed-out particles at the vortex center.

  In view of the above problems, an object of the present invention is to provide a substrate cleaning apparatus that can change the center position of a vortex formed by a supercritical fluid in a substrate cleaning space.

  In order to solve the above problems, a substrate cleaning apparatus according to the present invention is a substrate cleaning apparatus that cleans the surface of a substrate with a supercritical fluid, and includes a substrate cleaning chamber having a cleaning space for cleaning the substrate. The substrate cleaning chamber is provided with a plurality of intervals for discharging a supercritical fluid into the cleaning space at a predetermined angle with respect to the inner wall. A fluid discharge section, a distribution channel for distributing supercritical fluid supplied from the outside to the plurality of fluid discharge sections, and an opposing wall facing the substrate disposed in the cleaning space; And a fluid discharge part for discharging the supercritical fluid in the cleaning space to the outside, and the distribution flow path is divided into a plurality of partial flow path parts, and each partial flow path part is externally provided. Supercritical fluid is supplied One said fluid discharge portion, characterized in that it is connected.

  According to such a configuration, the supercritical fluid is discharged into the cleaning space at a predetermined angle with respect to the inner wall from the inner wall side of the substrate cleaning chamber that defines the cleaning space, whereby the substrate disposed in the cleaning space. A supercritical fluid vortex is formed along the surface. The substrate surface is cleaned by the vortex of the supercritical fluid.

  Moreover, since the distribution flow path for distributing the supercritical fluid to each fluid discharge part is divided into a plurality of partial flow path parts, each of the partial flow path parts is supplied with the supercritical fluid from the outside, It is possible to adjust the amount of supercritical fluid supplied to the partial flow path section. Therefore, the position of the vortex center of the supercritical fluid formed in the cleaning space can be changed.

  By changing the position of the vortex center in this way, the slow stagnation of the flow generated in the vortex center can be prevented from staying at a fixed position, and the resist stripping process on the substrate surface can be effectively performed. It can be carried out. In addition, since the position where the particles are concentrated also moves, the generation of scratches at the position corresponding to the vortex center on the substrate surface is suppressed.

  In the substrate cleaning apparatus according to the present invention, each of the partial flow path portions may be configured to be connected to a plurality of the fluid discharge portions.

  According to such a configuration, it is possible to adjust the discharge amount of the supercritical fluid for each group of the group of fluid discharge units connected to the same partial flow path unit, and it becomes easier to change the position of the vortex center of the fluid accordingly. .

  The plurality of fluid discharge units may be provided on the inner wall at equal intervals and so as to discharge the supercritical fluid along a common plane.

  According to such a configuration, a stable supercritical fluid vortex is easily formed in the cleaning space, and the control of the vortex of the supercritical fluid, that is, the position change of the vortex center can be easily performed.

  Moreover, the front end surface of the fluid discharge part may be flush with or substantially flush with the wall surface of the inner wall.

  According to such a configuration, the front end surface of each fluid discharge part does not protrude from the inner wall surface into the cleaning space, or protrudes only slightly. Therefore, the flow of the supercritical fluid formed in the cleaning space is not disturbed by each fluid discharge section, and forms a stable supercritical fluid vortex inside the cleaning space.

  Further, the same number of fluid discharge portions may be connected to each partial flow path portion.

  According to this configuration, it becomes easier to control the vortex of the supercritical fluid.

  Further, the distribution channel may be configured to have the same inner diameter at each position in the axial direction.

  According to such a configuration, the pressure at each position in the axial direction in the distribution flow path becomes substantially the same, and the supercritical fluid is supplied to each fluid discharge section connected to the common partial flow path section with the same pressure. Therefore, the discharge amount from each fluid discharge part in the common partial flow path part becomes the same, and it becomes easy to control (adjust) the discharge amount of the supercritical fluid discharged into the cleaning space. As a result, it becomes easy to control vortices formed in the cleaning space.

  The distribution channel may be arranged outside the wall surface of the inner wall and along the wall surface.

  According to such a configuration, the length from the distribution flow path to the front end surface of each fluid discharge section is the same, and it becomes easier to control the vortex of the supercritical fluid.

  Further, each partial flow channel portion is connected to a flow rate adjusting flow channel for supplying a supercritical fluid to the partial flow channel portion from the outside of the substrate cleaning chamber, and each flow rate adjusting flow channel has a flow rate adjusting means. May be provided.

  According to such a configuration, it is easier to adjust the flow rate of the supercritical fluid supplied to each partial flow path portion. Therefore, it becomes easier to control (adjust) the supercritical fluid discharge amount for each group of fluid discharge portions connected to the common partial flow path portion, and it is also easier to control the vortices formed in the cleaning space. Become.

  As described above, according to the present invention, it is possible to provide a substrate cleaning apparatus capable of changing the center position of the vortex formed by the supercritical fluid in the substrate cleaning space.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

The substrate cleaning apparatus according to the present embodiment uses a supercritical fluid (hereinafter simply referred to as “supercritical fluid”) to which a cleaning agent or the like is added, and a glass substrate for a semiconductor substrate (wafer) or a flat panel display (FPD). (Hereinafter, both are also simply referred to as “substrate”). In particular, the apparatus is used for cleaning a substrate on which a fine circuit pattern is formed so as not to cause pattern collapse. Note that the supercritical fluid used in the present embodiment is carbon dioxide (CO ₂ ) that has become a supercritical state by being placed under a high temperature and high pressure above the critical point.

  Specifically, as shown in FIG. 1, the substrate cleaning apparatus 10 circulates a substrate cleaning chamber 20 for cleaning the substrate w (see FIG. 2) and a supercritical fluid discharged from the substrate cleaning chamber 20. A circulation channel pipe 11 for supplying the substrate cleaning chamber 20 again, a circulation pump 12 provided in the middle of the circulation channel pipe 11 for circulating the supercritical fluid in the circulation channel pipe 11, and a circulation A flow rate adjusting unit 13 that adjusts the flow rate of the supercritical fluid that is provided immediately upstream of the substrate cleaning chamber 20 in the flow path pipe 11 and flows into the substrate cleaning chamber 20, and a flow rate control that controls the flow rate adjusting operation of the flow rate adjusting unit 13. Means C.

  The substrate cleaning chamber 20 is a chamber in which a resist stripping process and a cleaning process for the substrate w are performed using a supercritical fluid. As shown in FIGS. 2 to 4B, the substrate cleaning chamber 20 includes a cleaning space S for storing and cleaning a substrate (processing substrate) w, and a supercritical fluid in the cleaning space S. .., A distribution flow path 22 for distributing the supercritical fluid supplied from the circulation flow path pipe 11 to each fluid discharge section 21, and the cleaning space S The chamber body B has a fluid discharge portion 23 for discharging the supercritical fluid to the outside.

  The cleaning space S is a space formed in a horizontal substantially disk shape, and when the substrate w is arranged, a circumferential inner wall 25 surrounding the substrate w from the peripheral direction and a pair of upper and lower opposing walls (upper side) (Opposite wall and lower opposing wall) 26, 27. The inner wall 25 has a circular shape in plan view, and the inner wall 25 is provided with a plurality of fluid discharge portions 21, 21,. The lower facing wall 27 is constituted by an upper part of a stage 28 that can be moved up and down, is formed so that the upper surface is a smooth horizontal surface, and the substrate w carried into the cleaning space S is disposed. When the stage 28 is lowered or raised, the substrate insertion port 29 for communicating the cleaning space S with the outside and carrying the substrate w into and out of the cleaning space S opens and closes (FIG. 4A and FIG. 4). 4 (b)).

  A vertically extending piston 28a is connected to the lower side of the stage 28, and a large-diameter portion 28b is formed in the middle portion of the piston 28a.

  The upper facing wall 26 has a peripheral edge portion 26a inclined radially outward and upward, and a pair (two) of fluid discharge portions 23, 23 are provided in the central portion. In addition, the fluid discharge part 23 does not need to be limited to two, One or three or more may be sufficient. By providing two or more fluid discharge portions 23, the center position of the vortex of the supercritical fluid formed in the cleaning space S is moved by switching the fluid discharge portion 23 that discharges the supercritical fluid as will be described later. be able to.

  Each fluid discharge unit 23 is connected to a flow path switching valve 30 disposed outside the substrate cleaning chamber 20 via a discharge pipe 31. The flow path switching valve 30 switches the fluid discharge section 23 that discharges the supercritical fluid from the cleaning space S. That is, the pair of fluid discharge portions 23 and 23 are switched by the flow path switching valve 30 so as to alternately discharge the supercritical fluid in the cleaning space S. The flow path switching valve 30 is connected to the circulation flow path pipe 11 and allows the supercritical fluid from the fluid discharge portion 23 to flow into the circulation flow path pipe 11.

  The plurality of fluid discharge portions 21, 21,... Are provided at intervals along the inner wall 25, and provided so as to discharge the supercritical fluid into the cleaning space S at a predetermined angle α with respect to the inner wall 25. Yes. Specifically, the plurality of fluid discharge portions 21, 21,... Are provided on the inner wall 25 so as to be equally spaced along the circumferential direction of the inner wall 25 and are a common surface (horizontal virtual surface V: see FIG. 2). ) To discharge the supercritical fluid. That is, all the fluid discharge parts 21, 21,... Are provided at the same height with respect to the wall surface of the lower facing wall 27. Each fluid discharge section 21 is provided so as to discharge (spout) a supercritical fluid in a clockwise direction in a plan view so that the horizontal angle with respect to the inner wall 25 is α. Each fluid discharge portion 21 is formed in an arc shape that is equal in length and inner diameter and is curved in the clockwise direction along the horizontal virtual plane V. Further, each fluid discharge portion 21 is provided on the inner wall 25 so that the discharge-side front end surface is flush with the wall surface of the inner wall 25.

  In the present embodiment, each fluid discharge portion 21 is provided such that the discharge-side front end surface thereof is flush with the wall surface of the inner wall 25, but a supercritical state described later formed in the cleaning space S. It may protrude from the wall surface as long as it does not hinder vortices due to fluid. In addition, each fluid discharge portion 21 may be formed by separating the inner wall 25 in the vertical direction at the position of the virtual plane V, cutting a groove in the facing separation surface, and combining the separated inner walls 25 together. May be formed by embedding in the inner wall 25.

  The distribution flow path 22 is divided into a plurality of partial flow path sections 22a, 22a,..., And each partial flow path section 22a is supplied with supercritical fluid from the circulation flow path pipe 11 and connected to the fluid discharge section 21. ing. In the present embodiment, the distribution flow path 22 is divided into two partial flow path portions 22a and 22a. Specifically, the distribution flow path 22 has a plurality of partial flow path portions 22a and 22a having a shape obtained by dividing an annular flow path that is concentric with the wall surface of the inner wall 25 so that the axial lengths thereof are equal. , ... The distribution flow path 22 is formed outside the wall surface (in the radial direction outside the cleaning space S) so that the distance from the wall surface of the inner wall 25 is constant, and the inner diameter at each position in the axial direction is the same. It is formed as follows. In addition, an equal number of fluid discharge portions 21 are connected to each of the partial flow passage portions 22a, and the inner diameter of the distribution flow passage 22 (partial flow passage portion 22a) is larger than the inner diameter of the fluid discharge portion 21. Is also big.

  The circulation flow path pipe 11 is a pipe line for supplying the supercritical fluid discharged from the cleaning space S of the substrate cleaning chamber 20 to the cleaning space S. The circulation channel pipe 11 has a number of (two in the present embodiment) flow rate adjustment pipes (flow rate adjustment flows) corresponding to the partial flow path portions 22 a on the downstream side of the circulation pump 12 and the upstream side of the substrate cleaning chamber 20. Road) 14. The branched flow rate adjusting pipes 14 are connected to the corresponding partial flow path portions 22a. In the present embodiment, each flow rate adjusting pipe 14 is once branched into two (two) parallel flow path pipes 14a and 14b, and the branched parallel flow path pipes 14a and 14b join at the downstream end.

  The flow rate adjusting means 13 is provided in each flow rate adjusting pipe 14. By adjusting these flow rate adjusting means 13, it is possible to adjust the flow rate of the supercritical fluid that circulates inside each flow rate adjusting pipe 14. Thus, by adjusting the flow rate of the supercritical fluid flowing through each flow rate adjusting pipe 14, the flow rate of the supercritical fluid supplied to each partial flow path portion 22a is adjusted for each partial flow path portion 22a. The In the present embodiment, the flow rate adjusting means 13 includes an on-off valve 13a provided in the first parallel flow channel pipe 14a of the parallel flow channel tubes 14a and 14b and an orifice provided in the second parallel flow channel pipe 14b. (Aperture) 13b.

  The on-off valve 13a is a valve that can be switched between an open state in which the supercritical fluid can flow in the first parallel flow channel pipe 14a and a closed state in which the supercritical fluid cannot flow. . The on / off control of the on / off valve 13a is controlled by the flow rate control means C. Details of this control will be described later.

  In the present embodiment, an air operated valve is used as the on-off valve 13a. The air operated valve (open / close valve) 13a is connected to the flow rate control means C by an air pipe 15 provided with an electromagnetic valve 15a on the way. Then, the solenoid valve 15a is controlled to open and close by a controller (not shown) provided in the flow rate control means C, and air is supplied to the air operated valve 13a via the air pipe 15 or the supply of air is stopped. The air operated valve 13a is controlled to open and close.

The circulation channel pipe 11 includes an exhaust pipe (exhaust line) 16, a carbon dioxide (CO ₂ ) supply pipe (CO ₂ supply line) 17, a cleaning agent on the downstream side of the substrate cleaning chamber 20 and the upstream side of the circulation pump 12. (Additive) supply pipes (cleaning agent supply lines) 18 are connected to each other. Each of these lines 16, 17, 18 is provided with a valve. Exhaust of carbon dioxide from the circulation channel pipe 11 is performed by opening and closing a valve 16a provided in the exhaust pipe 16. Carbon dioxide is supplied to the circulation channel pipe 11 by opening and closing a valve 17 a provided in the carbon dioxide supply pipe 17. The cleaning agent is supplied to the circulation flow path pipe 11 by opening and closing a valve 18 a provided in the cleaning agent supply pipe 18.

  The circulation channel pipe 11 is provided with a filter 19 on the downstream side of the circulation pump 12 and on the upstream side of the flow rate adjusting pipe 14. The filter 19 is for removing particles generated during the substrate cleaning process from the supercritical fluid passing through the filter 19 and preventing the particles from reattaching to the substrate w.

  The substrate cleaning apparatus 10 according to the present embodiment has the above configuration, and next, the operation of the substrate cleaning apparatus 10 will be described.

  First, the fluid is injected into the gap s1 with the chamber body B above the large-diameter portion 28b of the piston 28a below the stage 28, whereby the piston 28a is pushed down and the stage 28 is lowered. In the state where the stage 28 is lowered, the substrate w is carried into the cleaning space S from the substrate insertion port 29 opened on the side of the substrate cleaning chamber 20 (see FIG. 4A).

  After the substrate w is carried in, the fluid is discharged from the gap s1 with the chamber body B on the upper side of the large-diameter portion 28b, and the fluid is injected into the lower gap s2. At the same time, fluid is also injected into the gap s3 with the chamber body B below the piston 28a. By injecting the fluid in this way, the piston 28a is pushed up and the stage 28 is raised. At this time, the substrate insertion port 29 is closed by the side wall of the stage 28, and the cleaning space S is in a liquid-tight and air-tight state.

Next, the valve 17a is opened with the valve 16a closed to constitute a circulation cycle in which a supercritical fluid such as the circulation channel pipe 11, the circulation pump 12, and the substrate cleaning chamber 20 circulates from the carbon dioxide supply pipe 17. The element is filled with a supercritical fluid (supercritical CO ₂ ). Further, the valve 18a is temporarily opened, a predetermined amount of cleaning agent is added to the supercritical fluid from the cleaning agent supply pipe 18, and the supercritical fluid is circulated in the circulation cycle by the circulation pump 12. By this circulation, in the substrate cleaning chamber 20, the supercritical fluid is discharged from the fluid discharge portion 21 into the cleaning space S, heads toward the center of the cleaning space S, and is discharged from the fluid discharge portion 23 to the outside.

  By such a flow of the supercritical fluid in the cleaning space S, cleaning (cleaning processing) of the substrate surface such as resist peeling processing and particle cleaning of the substrate surface carried into the cleaning space S is performed. At this time, the flow of the supercritical fluid formed in the cleaning space S is controlled by opening / closing control of the opening / closing valve 13a of each flow rate adjusting pipe 14 and control of switching timing of the flow path switching valve 30 as described later. When the cleaning of the substrate w is completed, the valve 16a of the exhaust pipe 16 is opened, and the supercritical fluid is discharged through the exhaust pipe 16 from the circulation cycle. After discharging the supercritical fluid, the substrate w is unloaded from the cleaning space S in the reverse procedure of loading.

  FIG. 5A to FIG. 6B also illustrate the opening / closing control of the opening / closing valve 13a and the switching timing of the flow path switching valve 30 when cleaning the surface of the substrate w by the flow of the supercritical fluid in the cleaning space S. This will be described with reference to FIG.

  A supercritical fluid is supplied from the circulation channel pipe 11 into the cleaning space S of the substrate cleaning chamber 20 with all the on-off valves 13a opened. Specifically, the supercritical fluid is sent out from the circulation pump 12 to the circulation flow path pipe 11 and reaches each partial flow path portion 22 a constituting the distribution flow path 22 via the pair of flow rate adjustment pipes 14 and 14. More specifically, the flow of the supercritical fluid flowing through each flow rate adjusting pipe 14 is once divided to flow in the first and second parallel flow path pipes 14a and 14b provided in each flow rate adjusting pipe 14, respectively. The Then, after passing through the on-off valve 13a in the first parallel flow path pipe 14a and after passing through the orifice 13b in the second parallel flow path pipe 14b, the parallel flow path pipes 14a and 14b join together, thereby dividing the flow. The flow of the supercritical fluid thus joined also joins, and after this joining, the supercritical fluid reaches the partial flow path portion 22a. At this time, since the flow rate of the supercritical fluid flowing through each flow rate adjusting pipe 14 is the same, the flow rate of the supercritical fluid supplied to each partial flow path portion 22a is the same.

  In this way, the supercritical fluid is supplied from the circulation flow channel pipe 11 to each partial flow channel portion 22a, and is supplied from each partial flow channel portion 22a to each fluid discharge portion 21 connected to the partial flow channel portion 22a. The

  In that case, since the partial flow path part 22a is comprised by the same internal diameter in the axial direction, the pressure in each position in an axial direction becomes the same. Therefore, the supercritical fluid is supplied to each fluid discharge part 21 connected to the common (same) partial flow path part 22a at the same pressure, and a group (plural) connected to the common partial flow path part 22a. .. Of the supercritical fluid discharged into the cleaning space S from the fluid discharge portions 21, 21,... In addition, since the flow rate of the supercritical fluid supplied to each partial flow path portion 22a is the same as described above, the flow rates of the supercritical fluid discharged from all the fluid discharge portions 21 provided on the inner wall 25 are respectively It will be the same.

  When the supercritical fluid supplied into the cleaning space S is discharged from each fluid discharge portion 21, the cleaning space S is rotated clockwise from the inner wall 25 of the substrate cleaning chamber 20 defining the cleaning space S in the clockwise direction. S is discharged into S. By being discharged in this way, the supercritical fluid flows while forming a vortex along the substrate surface disposed in the cleaning space S from the inner wall 25 side toward the center of the cleaning space S. A pseudo single wafer spin cleaning is performed on the substrate w by the vortex of the supercritical fluid.

  At this time, the flow path switching valve 30 is switched so that the supercritical fluid is discharged from one (the left side in FIG. 5A) fluid discharge portion 23. Therefore, the supercritical fluid flowing in a spiral shape flows in the cleaning space S along the substrate w from the inner wall 25 side toward the center, and is formed at the center of the upper facing wall 26 at the center of the cleaning space S. It flows so as to rise while spiraling toward the fluid discharge part 23 on the one side (see FIG. 5A).

  In this state, when the flow path switching valve 30 is switched, the fluid discharge portion 23 that discharges the supercritical fluid from the cleaning space S is switched to the other side (the right side in FIG. 5A). For this reason, the direction of the rising flow is switched, and accordingly, the slow flow region (stagnation) p of the supercritical fluid formed at the center of the vortex moves (see FIG. 5B). By repeating the switching of the flow path switching valve 30, the stagnation p reciprocates along the radial direction of the cleaning space S on the substrate w. The switching timing of the flow path switching valve 30 is performed at a predetermined cycle by a timer (not shown). The timer switching cycle can be arbitrarily adjusted.

  Further, the flow rate of the supercritical fluid flowing through each flow rate adjusting pipe 14 is adjusted by controlling each flow rate adjusting means 13 while the supercritical fluid flows so as to rise while winding the vortex, and the stagnation p is set. Can be moved. Specifically, the two on-off valves 13a and 13a are alternately opened and closed. That is, one on-off valve 13a is opened and the other on-off valve 13a is closed, and then one on-off valve 13a is closed and the other on-off valve 13a is opened. Each on-off valve 13a is controlled by the flow rate control means C so that each state is repeated for a predetermined time, whereby the flow rate of the supercritical fluid flowing through each flow rate adjustment pipe 14 is adjusted.

  Specifically, in the flow rate adjustment pipe 14 with the on-off valve 13a closed, the flow of the supercritical fluid in the first parallel flow path pipe 14a stops, and the supercritical fluid flows only in the second parallel flow path pipe 14b. Flowing. Therefore, a supercritical fluid having a flow rate (small flow rate) defined by the orifice 13b flows through the flow rate adjustment pipe 14 with the on-off valve 13a closed, and is supplied to the partial flow path portion 22a to which the flow rate adjustment pipe 14 is connected. The In contrast, in the flow rate adjusting pipe 14 with the open / close valve 13a opened, in addition to the supercritical fluid flowing in the second parallel flow path pipe 14b whose flow rate is regulated by the orifice 13b, the first parallel flow path is provided. The supercritical fluid also flows through the pipe 14a, and the supercritical fluid in a combined amount (large flow rate) is supplied to the partial flow path portion 22a to which the flow rate adjusting pipe 14 is connected.

  Since the flow rate of the supercritical fluid flowing through each flow rate adjusting pipe 14 can be changed by opening and closing each open / close valve 13a in this way, the open / close valves 13a and 13a provided in the pair of flow rate adjusting pipes 14 and 14 respectively. By controlling so as to be alternately opened and closed, the flow rates of the supercritical fluid supplied to the two partial flow path portions 22a and 22a alternately increase.

  Accordingly, when the on-off valve 13a of one of the pair of flow rate adjusting pipes 14 and 14 is opened, a group of fluid discharges provided in the partial flow path portion 22a to which the flow rate adjusting pipe 14 is connected. Are discharged from a group of fluid discharge sections 21, 21,... Provided in the partial flow path section 22a to which a high flow rate supercritical fluid is discharged and the other flow rate adjustment pipe 14 is connected. A small flow of supercritical fluid is discharged. As described above, the center of the vortex is the center of the cleaning space S because the discharge amount of the one group of fluid discharge sections 21, 21,... And the other group of fluid discharge sections 21, 21,. It moves from the position (see the arrow in FIG. 6A). Next, when the on-off valve 13a of the other flow rate adjusting pipe 14 is opened, the discharge amount of the one group of fluid discharge sections 21, 21,... And the group of fluid discharge sections 21, 21, on the other side. The discharge amount discharged from the reverse is reversed, and the center of the vortex moves to the opposite side in the radial direction (see the arrow in FIG. 6B). The movement of the position of the vortex center is larger than the movement by switching the switching valve 30, and the movement of the stagnation p is also larger.

  In this way, the control of the flow rate adjusting means 13 in each flow rate adjusting pipe 14 (in this embodiment, the on / off control of the on / off valve 13a) adjusts the flow rate of the supercritical fluid or the switching timing of the flow path switching valve 30. By the adjustment, the position of the vortex center of the supercritical fluid formed in the cleaning space S can be moved on the substrate w.

  Furthermore, the position of the vortex center of the supercritical fluid is more freely controlled by combining control of the flow rate adjusting means 13 (open / close control of the on-off valve 13a) and adjustment of the switching timing of the flow path switching valve 30. Can be moved.

  Next, the operation and effect of the substrate cleaning apparatus 10 according to the present embodiment will be described.

  In the substrate cleaning apparatus 10, the supercritical fluid is discharged into the cleaning space S at a predetermined angle α with respect to the inner wall 25 from the inner wall 25 side of the substrate cleaning chamber 20 that defines the cleaning space S. A vortex of the supercritical fluid is formed along the surface of the substrate w arranged in S. The surface of the substrate w is cleaned by the supercritical fluid vortex.

  Moreover, the distribution flow path 22 that distributes the supercritical fluid to each fluid discharge section 21 is divided into two partial flow path sections 22a and 22a, and each of the partial flow path sections 22a has a circulation flow path pipe 11, more specifically, A supercritical fluid is supplied from the flow rate adjusting pipe 14. Therefore, it is possible to adjust the amount of supercritical fluid supplied to each partial flow path portion 22a by controlling the flow rate adjusting means 13 of the flow rate adjusting pipe 14. Therefore, the position of the vortex center of the supercritical fluid formed in the cleaning space S can be changed. That is, the vortex center moves on the substrate w.

  By changing the position of the vortex center in this way, it is possible to prevent the slow flow region generated at the vortex center, that is, the stagnation p from staying at a fixed position, so that the resist is peeled from the surface of the substrate w. Processing can be performed effectively. In addition, since the position where the particles are concentrated also moves, the generation of scratches at the position corresponding to the vortex center on the surface of the substrate w is suppressed.

  Moreover, each partial flow path part 22a is connected to a plurality of fluid discharge parts 21, 21,. Therefore, the discharge amount of the supercritical fluid for each group of the group of fluid discharge parts 21 connected to the same partial flow path part 22a can be adjusted, and the position change of the vortex center of the fluid becomes easier accordingly.

  Further, the plurality of fluid discharge portions 21, 21,... Are provided at equal intervals on the inner wall 25 and are provided so as to discharge the supercritical fluid along a common plane (horizontal virtual plane) V. Therefore, a stable supercritical fluid vortex is easily formed in the cleaning space S, and control of the vortex of the supercritical fluid, that is, control for moving the position of the vortex center is facilitated.

  Further, the front end surface of the fluid discharge portion 21 is flush with the wall surface of the inner wall 25. Therefore, the front end surface of each fluid discharge part 21 does not protrude into the cleaning space S from the inner wall surface (the wall surface of the inner wall 25). As a result, the flow of the supercritical fluid is not disturbed by each fluid discharge section 21 and forms a stable supercritical fluid vortex inside the cleaning space S.

  In addition, since the same number of fluid discharge portions 21 are connected to each partial flow path portion 22a, it becomes easier to control the vortex of the supercritical fluid. In addition, since the distribution flow path 22 is configured to have the same inner diameter at each position in the axial direction, the pressure at each position in the axial direction in the distribution flow path 22 is substantially the same, and the distribution flow path 22 is divided. The supercritical fluid is supplied to each fluid discharge part 21 connected to the same (common) partial flow path part 22a of the plurality of partial flow path parts 22a, 22a,. Therefore, the discharge amount from each fluid discharge part 21 in the common partial flow path part 22a becomes the same, and it becomes easy to control (adjust) the discharge amount of the supercritical fluid discharged into the cleaning space S. As a result, it becomes easy to control vortices formed in the cleaning space S.

  In addition, since the distribution flow path 22 is disposed outside and along the wall surface of the inner wall 25, the length from the distribution flow path 22 (partial flow path portion 22a) to the distal end surface of each fluid ejection section 21 is increased. It is possible to control the vortices of the supercritical fluid more easily.

  In addition, a flow rate adjusting pipe (flow rate adjusting flow path) 14 is connected to each partial flow path portion 22a, and each flow rate adjusting pipe 14 is provided with a flow rate adjusting means 13, respectively. Therefore, it becomes easier to adjust the flow rate of the supercritical fluid supplied to each partial flow path portion 22a. As a result, it becomes easier to control (adjust) the discharge amount of the supercritical fluid for each group of fluid discharge portions 21 connected to the common partial flow path portion 22a, and control of vortices formed in the cleaning space S. Becomes easier to do.

  The substrate cleaning apparatus of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

  For example, in the present embodiment, the distribution flow path 22 is configured by two partial flow path portions 22a and 22a, but is not limited to this, and is configured by three or more partial flow path portions. May be. By being configured in this way, the position of the vortex center can be moved more freely by controlling the flow rate adjusting means in the flow rate adjusting pipe connected to each partial flow path portion.

  Further, in the present embodiment, the flow rate adjusting means 13 is constituted by the on-off valve 13a and the orifice 13b provided in parallel to each flow rate adjusting pipe 14, but the present invention is not limited to this, and the opening degree is not limited. You may comprise the flow regulating valve which can be adjusted. Even if such a valve is used as the flow rate adjusting means 13, the flow rate of the supercritical fluid flowing in the flow rate adjusting tube can be adjusted for each flow rate adjusting tube.

The schematic block diagram of the board | substrate cleaning apparatus which concerns on this embodiment is shown. FIG. 2 is a partially enlarged configuration diagram of a substrate cleaning chamber in the substrate cleaning apparatus according to the embodiment. The partially expanded block diagram in the AA cross section of FIG. 2 is shown. In the substrate cleaning apparatus according to the embodiment, (a) shows a schematic configuration diagram of the substrate cleaning chamber with the stage lowered, and (b) shows a schematic configuration diagram of the substrate cleaning chamber with the stage raised. In the substrate cleaning apparatus according to the embodiment, (a) shows a conceptual diagram of the flow of the supercritical fluid in a state where the supercritical fluid is discharged from one fluid discharge portion, and (b) shows from the other fluid discharge portion. The conceptual diagram of the flow of the supercritical fluid in the state where the supercritical fluid is discharged is shown. In the substrate cleaning apparatus according to the embodiment, (a) shows a conceptual diagram of the flow of the supercritical fluid in a state in which the on-off valve of one flow rate adjustment pipe is closed, and (b) shows the on-off valve of the other flow rate adjustment pipe The conceptual diagram of the flow of the supercritical fluid of the state which closed is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate cleaning apparatus 20 Substrate cleaning chamber 21 Fluid discharge part 22 Distribution flow path 22a Partial flow path part 23 Fluid discharge part 25 Inner wall 26 Upper opposing wall (opposing wall)
S Cleaning space w Substrate α Angle

Claims (8)

A substrate cleaning apparatus for cleaning the surface of a substrate with a supercritical fluid,
A substrate cleaning chamber having a cleaning space for cleaning the substrate;
The substrate cleaning chamber is provided at intervals along an inner wall that defines the cleaning space, and a plurality of fluid discharges for discharging supercritical fluid into the cleaning space at a predetermined angle with respect to the inner wall. And
A distribution flow path for distributing the supercritical fluid supplied from the outside to the plurality of fluid discharge portions,
A fluid discharge part provided on an opposing wall facing the substrate disposed in the cleaning space, and discharging the supercritical fluid in the cleaning space to the outside,
The distribution channel is divided into a plurality of partial channel parts,
The substrate cleaning apparatus, wherein each partial flow path section is supplied with a supercritical fluid from the outside and connected to the fluid discharge section.   The substrate cleaning apparatus according to claim 1, wherein each of the partial flow path units is connected to a plurality of the fluid discharge units.   The substrate cleaning apparatus according to claim 1, wherein the plurality of fluid discharge units are provided at equal intervals on the inner wall and are provided so as to discharge a supercritical fluid along a common plane.   The substrate cleaning apparatus according to claim 1, wherein a front end surface of the fluid discharge unit is flush with or substantially flush with a wall surface of the inner wall.   5. The substrate cleaning apparatus according to claim 1, wherein an equal number of fluid ejection units are connected to each of the partial flow path units.   The substrate cleaning apparatus according to claim 1, wherein the distribution channel is configured to have the same inner diameter at each position in the axial direction.   The substrate cleaning apparatus according to claim 5, wherein the distribution channel is disposed outside and along the wall surface of the inner wall.   A flow rate adjusting flow path for supplying a supercritical fluid to the partial flow path portion from the outside of the substrate cleaning chamber is connected to each partial flow path portion, and a flow rate adjusting means is provided for each flow rate adjusting flow path. The substrate cleaning apparatus according to claim 1, wherein the substrate cleaning apparatus is provided.

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