Circuit board cleaning apparatus and circuit board cleaning method

Abstract

To improve the throughput of a substrate cleaning method using freeze cleaning. [Solution] The substrate cleaning apparatus according to the embodiment comprises: a rotating holding unit for holding a substrate; a liquid supply unit for supplying liquid to a first surface of the substrate; a first cooling medium supply unit for supplying a first cooling medium toward a second surface of the substrate opposite to the first surface; a second cooling medium supply unit for supplying a second cooling medium toward the first surface; and a control unit for controlling the rotating holding unit, the first cooling medium supply unit, the second cooling medium supply unit, and the liquid supply unit to perform a cleaning process on the substrate, wherein the cleaning process includes: a first cooling process for freezing the liquid on the first surface to form a frozen body by supplying the first cooling medium toward the second surface; and a second cooling process for further cooling the frozen body by supplying the second cooling medium toward the first surface.

Description

Technical Field

[0001] One embodiment of the present invention relates to a substrate cleaning apparatus and a substrate cleaning method.

Background Art

[0002] Conventionally, as a substrate cleaning method for removing foreign substances such as particles adhering to the surface to be processed of a substrate such as a semiconductor substrate, an imprint template, or a photolithography mask, a freeze cleaning method is known. In the freeze cleaning method, first, pure water is supplied to the surface of the substrate, and the substrate is rotated to form a water film on the surface of the substrate. After forming the water film, a cooling gas is supplied to the substrate to freeze the water film, and the particles are incorporated into the ice film using the volume expansion force during the phase change from liquid to solid. Then, by supplying pure water to the substrate again to melt the ice film, the particles can be removed from the substrate together with the pure water.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the above-described freeze cleaning method, it is possible to effectively remove foreign substances such as particles adhering to the surface of the substrate. However, for example, in the manufacturing process of semiconductor devices, since the cleaning process of a large number of semiconductor substrates is performed in each manufacturing process, a lot of time is spent only on the cleaning process. Therefore, in recent years, an improvement in the throughput of the cleaning process has been desired.

[0005] One of the problems of the present invention is to improve the throughput of a substrate cleaning method using the freeze cleaning method.

[0006] Another objective of the present invention is to provide a substrate cleaning apparatus capable of performing a substrate cleaning method with improved throughput. [Means for solving the problem]

[0007] A substrate cleaning apparatus according to one embodiment of the present invention comprises: a rotating holding unit for holding a substrate; a liquid supply unit for supplying liquid to a first surface of the substrate; a first cooling medium supply unit for supplying a first cooling medium toward a second surface of the substrate opposite to the first surface; a second cooling medium supply unit for supplying a second cooling medium toward the first surface; and a control unit for controlling the rotating holding unit, the first cooling medium supply unit, the second cooling medium supply unit, and the liquid supply unit to perform a cleaning process on the substrate, wherein the cleaning process includes: a first cooling process for supplying the first cooling medium toward the second surface to freeze the liquid on the first surface and form a frozen body; and a second cooling process for supplying the second cooling medium toward the first surface to further cool the frozen body.

[0008] A substrate cleaning method according to one embodiment of the present invention includes supplying a liquid to a first surface of a substrate, supplying a first cooling medium toward a second surface of the substrate opposite to the first surface to freeze the liquid on the first surface and form a frozen body, and further cooling the frozen body by supplying a second cooling medium toward the first surface. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic side view showing the configuration of a substrate cleaning apparatus according to the first embodiment. [Figure 2] This is a schematic cross-sectional view showing the configuration of the main parts of the substrate cleaning apparatus according to the first embodiment. [Figure 3] This is a flowchart showing the configuration of a substrate cleaning method performed by a substrate cleaning apparatus according to the first embodiment. [Figure 4] This figure illustrates the relationship between the operation of the substrate cleaning apparatus according to the first embodiment and the temperature of the cleaning solution. [Figure 5]This is a flowchart showing the configuration of a substrate cleaning method performed by a substrate cleaning apparatus according to the second embodiment. [Figure 6] This figure illustrates the relationship between the operation of the substrate cleaning apparatus according to the second embodiment and the temperature of the cleaning solution. [Modes for carrying out the invention]

[0010] A substrate cleaning apparatus according to one embodiment of the present invention will be described below with reference to the drawings. However, the present invention can be carried out in many different forms and should not be construed as being limited to the examples shown below. In the drawings referenced in this embodiment, the same part or part having a similar function may be given the same reference numeral or the same reference numeral followed by an alphabet letter, and repeated descriptions may be omitted.

[0011] In the specification and claims of this application, "up" refers to the direction that the mounting surface of the substrate cleaning device (e.g., the factory floor) faces when the substrate cleaning device is installed in a state where it can be used normally, and "down" refers to the opposite direction from "up". Furthermore, with respect to the center of the substrate cleaning device in a plan view, the direction away from the center is referred to as "outside", and the direction towards the center is referred to as "inside".

[0012] <First Embodiment> As an example of a substrate cleaning apparatus according to one embodiment of the present invention, a substrate cleaning apparatus for cleaning semiconductor substrates (e.g., semiconductor wafers) will be described. However, the embodiment of the substrate cleaning apparatus is not limited to an apparatus for cleaning semiconductor substrates, and can also be applied to an apparatus for cleaning other substrates. For example, it can be applied to an apparatus for cleaning substrates such as imprint templates, photolithography masks, and plate-like bodies used in MEMS (Micro Electro Mechanical Systems).

[0013] In the following explanation, a semiconductor substrate without a coating (insulating film or conductive film) formed on the surface to be processed (front or back) is used as an example, but the explanation is not limited to this example. For example, the semiconductor substrate may be one with an unprocessed coating formed on the surface to be processed, or one with a processed coating (pattern) formed on the surface to be processed. Furthermore, in the following explanation, an example is shown in which a cooling gas is used as the cooling medium and pure water is used as the cleaning solution. Therefore, the liquid (cleaning solution) held on the surface to be processed (front) of the substrate W is called a "water film" or "liquid film," and the frozen body formed by freezing the liquid may be called an "ice film" or "frozen film."

[0014] [Configuration of the circuit board cleaning device 100] Figure 1 is a schematic side view showing the configuration of the substrate cleaning apparatus 100 according to the first embodiment. Figure 2 is a schematic cross-sectional view showing the configuration of the main part of the substrate cleaning apparatus 100 according to the first embodiment. The substrate cleaning apparatus 100 will be described below with reference to Figures 1 and 2. The substrate cleaning apparatus 100 is, for example, installed in a factory that manufactures semiconductor devices, and is a device that performs a cleaning process using a freeze cleaning method on a substrate W, which is the object to be cleaned (workpiece), between various manufacturing processes of semiconductor devices.

[0015] The substrate cleaning apparatus 100 of this embodiment includes a rotating holding unit 110, a first cooling medium supply unit 120, a second cooling medium supply unit 130, a liquid supply unit 140, a discharge cup unit 150, and a control unit 160. However, the configuration of the substrate cleaning apparatus 100 is not limited to this example, and some of the components shown in Figure 1 may be omitted, or other components may be added.

[0016] (Configuration of the rotating holding unit 110) The rotating holding unit 110 includes a base unit 111, a cover unit 112, a holding unit 113, and a drive unit 114. The rotating holding unit 110 holds the substrate W with the surface to be processed (in this case, the surface) facing upwards, and has the function of rotating the substrate W about a rotation axis 11 that passes vertically through the center of the rotating holding unit 110. However, the configuration of the rotating holding unit 110 is not limited to this example, and some of the above-mentioned components may be omitted, or other components may be added.

[0017] The base portion 111 is a rotating body that supports the cover portion 112 and the holding portion 113, and is a member having a substantially circular outer shape. In a plan view, a cylindrical portion 111a extending downward is provided at the center of the base portion 111. That is, an opening extending downward is provided at the center of the base portion 111 in a plan view. As will be described later, a part of the nozzle head portion 121 of the first cooling medium supply unit 120 (lower portion 121b) is fitted into the inside (hollow portion) of the cylindrical portion 111a. The nozzle head portion 121 is supported by a stand (not shown) and is separated from the base portion 111. The base portion 111 is rotatable about a rotation axis 11 that passes through the center of the cylindrical portion 111a.

[0018] The cover portion 112 is a member having a substantially circular outer shape and is disposed above the base portion 111. The cover portion 112 has an inner portion 112a located inside the holding portion 113 and an outer portion 112b located outside the holding portion 113. The inner portion 112a of the cover portion 112 is a portion fixed on the base portion 111 and has an inclined surface whose upper surface is positioned upward so as to face outward. Although details will be described later, the inclined surface provided on the inner portion 112a functions as a guide surface for guiding the cooling medium supplied to the back surface side of the substrate W outward. An opening 112aa is provided at the center of the inner portion 112a, and a part (upper portion 121a) of the above-described nozzle head portion 121 is fitted therein. The outer portion 112b of the cover portion 112 has a role as a cover for protecting the internal structure of the rotation holding portion 110. In the present embodiment, an example in which the base portion 111 and the cover portion 112 are configured as separate members is shown, but the base portion 111 and the cover portion 112 may be integrally formed members.

[0019] The holding portion 113, also called a chuck pin, is provided in a plurality at predetermined intervals on the outer peripheral portion of the base portion 111. The holding portion 113 has a columnar main body portion 113a configured to be rotatable by a drive mechanism (not shown) and a pin 113b provided at the upper end of the main body portion 113a. The pin 113b is provided at a position separated from the rotation axis of the main body portion 113a. When the main body portion 113a rotates, the pin 113b moves inward and abuts against the side end portion of the substrate W to hold the substrate W. On the other hand, when the main body portion 113a rotates in the opposite direction to the above-described direction, the pin 113b moves outward and detaches from the side end portion of the substrate W to release the substrate W.

[0020] The drive unit 114 is supported by a frame or the like (not shown) and is connected to the lower end of the base unit 111 (i.e., the lower end of the cylindrical portion 111a). The drive unit 114 has a function of rotating the base unit 111 about the rotation axis 11. An opening 114a is provided in the central portion of the drive unit 114, and a part (lower portion 121b) of the above-described nozzle head unit 121 is inserted therein. Since the drive unit 114 and the nozzle head unit 121 are not connected, the drive unit 114 can rotate the base unit 111 with the nozzle head unit 121 fixed.

[0021] (Configuration of the First Cooling Medium Supply Unit 120) The first cooling medium supply unit 120 includes a nozzle head unit 121, a dispersion plate 122, and a cooling medium supply device 123. The first cooling medium supply unit 120 has a role of supplying a cooling medium (first cooling medium) to cool the back surface (second surface) side of the substrate W. However, the configuration of the first cooling medium supply unit 120 is not limited to this example, and some of the above-described components may be omitted, or other components may be added.

[0022] In the present embodiment, a cooling gas is used as the cooling medium for cooling the back surface side of the substrate W. Specifically, in the present embodiment, nitrogen gas cooled to -120°C is used as the cooling gas. However, the cooling medium is not limited to this example, and other inert gases such as argon and helium cooled may be used, or vaporized liquid nitrogen may be used. Further, as the cooling medium, instead of the cooling gas, a cooled liquid can also be used.

[0023] The nozzle head portion 121 is a component that supplies cooling gas to the back side of the substrate W. The nozzle head portion 121 is located above the cylindrical portion 111a of the base portion 111 and includes an upper portion 121a with a roughly V-shaped cross-section and a lower portion 121b with a cylindrical shape. As shown in Figure 2, the upper portion 121a is positioned inside the opening 112aa of the cover portion 112, and the lower portion 121b is inserted inside the cylindrical portion 111a of the base portion 111. However, the base portion 111 and cover portion 112 and the nozzle head portion 121 are separated from each other, and while the base portion 111 and cover portion 112 can rotate around the rotation axis 11, the nozzle head portion 121 is fixed and does not rotate.

[0024] A through-hole 121c is provided in the center of the nozzle head portion 121, connecting the lower end and the upper end along the rotation axis 11. Specifically, the rotation axis 11 is located at the center of the through-hole 121c. The through-hole 121c is a path through which the cooling gas supplied from the cooling medium supply device 123 passes, and the cooling gas supplied from the lower end of the through-hole 121c is discharged from the upper end of the through-hole 121c toward the dispersion plate 122.

[0025] The upper surface of the upper portion 121a of the nozzle head 121 is provided with an inclined surface 121aa that is positioned higher as it extends outward. In other words, a conical depression is formed on the upper surface of the upper portion 121a of the nozzle head 121. Therefore, some of the cooling gas that reaches the upper surface of the nozzle head 121 via the through hole 121c flows upward and outward along the inclined surface 121aa provided on the upper surface of the upper portion 121a. In other words, the inclined surface 121aa functions as a guide surface for guiding the cooling gas supplied to the back side of the substrate W outward.

[0026] Furthermore, a circular groove 121ab is provided on the lower surface of the upper portion 121a of the nozzle head portion 121 in a plan view. On the other hand, the base portion 111 is provided with a projection 111b that protrudes upward, and the groove 121ab of the nozzle head portion 121 and the projection 111b of the base portion 111 are positioned apart from each other and facing each other. In this way, the gap between the base portion 111 and the nozzle head portion 121 forms a bent shape (labyrinth structure), which prevents the cleaning liquid supplied to the substrate W through the gap from entering the inside of the cover portion 112. In addition, this structure also prevents unclean gas (for example, gas containing fine particles such as dust) from leaking from the inside of the cover portion 112 to the space where the substrate W is processed.

[0027] The dispersion plate 122 is positioned at a distance above the upper portion 121a of the nozzle head portion 121. Specifically, the dispersion plate 122 is positioned above the nozzle head portion 121 with a predetermined gap using screws, pins, etc. The gap between the nozzle head portion 121 and the dispersion plate 122 is provided so that the cooling gas that flows outward along the upper surface (inclined surface 121aa) of the nozzle head portion 121 flows towards the inner portion 112a of the cover portion 112. Furthermore, when the substrate W is held by the holding portion 113, the dispersion plate 122 is positioned such that the gap between the dispersion plate 122 and the substrate W is, for example, 1 mm to 5 mm (2 mm in this embodiment).

[0028] The dispersion plate 122 is provided with a plurality of through holes 122a connecting its upper and lower surfaces. Although not shown in the illustration, in this embodiment, one through hole 122a is provided in the center, and a plurality of through holes 122a are provided surrounding that central hole. The cooling gas supplied through the through hole 121c of the nozzle head portion 121 rises and collides with the lower surface of the dispersion plate 122. At this time, a portion of the cooling gas passes through the through holes 122a of the dispersion plate 122 and hits the back surface of the substrate W. After that, the cooling gas that has reached the substrate W flows through the gap between the upper surface of the dispersion plate 122 and the back surface of the substrate W and is discharged to the outside of the rotating holding portion 110.

[0029] In this embodiment, one of the multiple through holes 122a is located in the center of the dispersion plate 122. However, it is preferable that the through hole 122a located in the center of the dispersion plate 122 is located at a position offset from the rotation axis 11. The center of the substrate W (the position where it intersects with the rotation axis 11) is the rotation center. Therefore, if cooling gas hits the center of the substrate W, cooling may proceed locally more than in other parts, potentially hindering uniform cooling of the substrate W. By positioning the through hole 122a located in the center of the dispersion plate 122 at a position offset from the center of the substrate W, the problem of localized cooling progressing only at the center of the substrate W can be suppressed.

[0030] On the other hand, even when the through-holes 122a are positioned in a location that overlaps with the rotation axis 11, it is possible to suppress localized cooling of the center of the substrate W by, for example, making the diameter of the through-hole 122a located in the center smaller than the diameter of the through-holes 122a located in other positions. In other words, by reducing the contact area of ​​the cooling gas with the center of the substrate W, the unevenness of the temperature distribution of the substrate W can be mitigated. In this case, the diameter of the through-hole 122a located in the center of the dispersion plate 122 may be smaller overall than the diameter of the through-holes 122a located in other positions, or the diameter of only the opening end may be increased by making the opening end facing the substrate W tapered.

[0031] The cooling medium supply device 123 is a device that supplies a cooling medium (in this case, cooling gas) to the nozzle head unit 121. Although not shown in the figures, the nozzle head unit 121 and the cooling medium supply device 123 are connected by piping or the like. Between the nozzle head unit 121 and the cooling medium supply device 123, a flow rate adjustment unit for adjusting the flow rate of the cooling gas and a filter unit for removing foreign matter contained in the cooling gas may also be provided. Although not shown in the figures, in this embodiment, the cooling medium supply device 123 includes a gas tank for storing nitrogen gas, a chiller (cooling water circulation device) for cooling the nitrogen gas, and a pump for sending the cooled nitrogen gas to the nozzle head unit 121. However, the configuration of the cooling medium supply device 123 is not limited to this example, and any device with any configuration that can supply cooled gas or liquid to the nozzle head unit 121 may be used.

[0032] (Configuration of the second cooling medium supply unit 130) The second cooling medium supply unit 130 includes a blocking member 131, a detection unit 132, a lifting mechanism 133, and a cooling medium supply device 134. The second cooling medium supply unit 130 has the role of supplying a cooling medium (second cooling medium) to cool the surface (first surface) of the substrate W. Specifically, the second cooling medium supply unit 130 supplies a cooling medium to further cool the frozen body (ice film in this embodiment) formed on the surface of the substrate W. However, the configuration of the second cooling medium supply unit 130 is not limited to this example, and some of the above-mentioned components may be omitted, or other components may be added.

[0033] In this embodiment, the same cooling gas (specifically, nitrogen gas cooled to -120°C) as the first cooling medium supply unit 120 is used as the cooling medium for cooling the surface side of the substrate W. However, this is not the only example, and the second cooling medium supply unit 130 may use a different cooling medium than the first cooling medium supply unit 120. Also, as with the first cooling medium supply unit 120, other types of cooling mediums may be used.

[0034] The blocking member 131 is a member that supplies cooling gas to a frozen body (in this case, an ice film) formed on the surface (processing surface) of the substrate W. Specifically, the blocking member 131 is composed of a plate-shaped member having a through hole 131a for supplying cooling gas. In plan view, the blocking member 131 has a circular outer shape and a through hole 131a in its center. The cooling gas supplied from the cooling medium supply device 134 is supplied to the ice film formed on the surface of the substrate W via the through hole 131a.

[0035] In the example shown in Figure 2, the through-hole 131a is located at a position that overlaps with the rotation axis 11 (i.e., opposite the through-hole 121c of the nozzle head portion 121). However, the through-hole 131a may be located at an offset position from the rotation axis 11, not limited to this example. The reason for this is the same as the reason explained for the through-hole 122a provided in the dispersion plate 122. By offsetting the position of the through-hole 131a from the center position of the substrate W, it is possible to suppress the problem of the temperature at the center of the ice film formed on the surface of the substrate W being locally lower than other parts. In this embodiment, the lower opening end 131c of the through-hole 131a has a tapered shape that widens downwards. Therefore, the contact area when the released cooling gas hits the ice film is increased, and the unevenness of the temperature distribution of the ice film can be suppressed.

[0036] It is desirable that the area of ​​the side of the shielding member 131 facing the substrate W is equal to or greater than the surface area of ​​the substrate W. As will be described later, when supplying cooling gas toward the surface of the substrate W, the shielding member 131 and the substrate W are brought close together to form a small gap between the shielding member 131 and the substrate W. In Figure 1, the shielding member 131 brought close to the substrate W is shown by a dotted line. The cooling gas released from the through hole 131a spreads outward through the gap formed between the shielding member 131 and the substrate W (more precisely, the ice film), cooling the entire surface of the ice film. Therefore, the area of ​​the side of the shielding member 131 facing the substrate W is set to be greater than or equal to the surface area of ​​the substrate W, so that the gap is formed up to the outer edge of the substrate W. It is preferable that the width of the gap formed between the substrate W and the shielding member 131 be the same as the width of the gap formed between the substrate W and the dispersion plate 122. For example, the width of the gap formed between the substrate W and the shielding member 131 may be 1 mm or more and 5 mm or less. In this embodiment, the width of the gap is set to 2 mm.

[0037] The detection unit 132 has the function of detecting whether an ice film has formed on the surface of the substrate W. In other words, the detection unit 132 has the function of detecting whether or not the liquid held on the surface of the substrate W has undergone a phase transition to a solid. In this embodiment, a radiation thermometer is used as the detection unit 132 to measure the radiation temperature of the water film or ice film held on the surface of the substrate W. In this embodiment, three radiation thermometers are attached to the shielding member 131 as the detection unit 132, at different radial positions on the shielding member 131 at intervals from each other. The three radiation thermometers only need to be at different radial positions and do not need to be lined up in a straight line. As shown in Figure 2, each radiation thermometer is positioned on the upper side of the shielding member 131 (i.e., the side opposite to the side facing the substrate W). In addition, each position on the shielding member 131 where the radiation thermometer is attached is provided with an opening 131b for allowing infrared rays to pass through.

[0038] In this embodiment, an example is shown in which three radiation thermometers are arranged on the shielding member 131 as the detection unit 132, but the number of radiation thermometers to be arranged is not limited to three. Also, in this embodiment, a configuration in which the radiation thermometers are attached to the shielding member 131 is illustrated, but instead, the radiation thermometers may be fixed to a member located outside the shielding member 131, and the radiation temperature of the water film or ice film may be measured from an oblique direction.

[0039] Alternatively, instead of a radiation thermometer, an imaging device may be used as the detection unit 132. That is, by using the imaging device to image the water film or ice film held on the surface of the substrate W and analyzing the captured image, it is possible to detect whether or not the water has undergone a phase transition to ice.

[0040] The lifting mechanism 133 has the function of moving the blocking member 131 vertically (up and down). The lifting mechanism 133 includes a first support frame 133a, a second support frame 133b, a support arm 133c, and a connecting part 133d. The first support frame 133a and the second support frame 133b are each cylindrical members, and the second support frame 133b is inserted through the hollow portion of the first support frame 133a. The second support frame 133b is connected to a drive mechanism (not shown) and is able to slide inside the first support frame 133a. That is, the second support frame 133b is movable vertically relative to the first support frame 133a, and the whole structure constitutes a support frame that can extend and retract vertically.

[0041] A support arm 133c is fixed near the upper end of the second support frame 133b. The support arm 133c is a member that connects the second support frame 133b and the connecting portion 133d, and supports the shut-off member 131 via the connecting portion 133d. The connecting portion 133d is a member that connects the support arm 133c and the shut-off member 131, and as shown in Figure 2, it has a through hole 133da inside that communicates with the through hole 131a of the shut-off member 131. The cooling gas supplied from the cooling medium supply device 134 is released toward the substrate W via the through hole 133da of the connecting portion 133d and the through hole 131a of the shut-off member 131.

[0042] The lifting mechanism 133 allows the blocking member 131 to move between a retracted position relatively far from the substrate W and a close position relatively close to the substrate W. The retracted position is a position where the blocking member 131 is sufficiently far from the rotating holding unit 110, and where the substrate W can be loaded into and unloaded from the rotating holding unit 110. The close position is a position where the blocking member 131 is sufficiently close to the rotating holding unit 110, and where the cooling process of the substrate W by the second cooling medium supply unit 130 is performed. In the close position, a gap is ensured between the substrate W and the blocking member 131 such that the blocking member 131 does not come into contact with the water film or ice film held on the substrate W. However, the configuration of the lifting mechanism 133 is not limited to this example, and any configuration is acceptable as long as the blocking member 131 can be moved in the vertical direction.

[0043] The cooling medium supply device 134 is a device that supplies a cooling medium (in this case, cooling gas) to the shut-off member 131. Although not shown in the figure, the shut-off member 131 and the cooling medium supply device 134 are connected by piping or the like. In this embodiment, the configuration of the cooling medium supply device 134 is the same as that of the cooling medium supply device 123. That is, the cooling medium supply device 134 includes a gas tank for storing nitrogen gas, a chiller (cooling water circulation device) for cooling the nitrogen gas, and a pump for sending the cooled nitrogen gas to the shut-off member 131. However, the configuration of the cooling medium supply device 134 is not limited to this example; any device capable of supplying a cooled medium to the shut-off member 131 is acceptable.

[0044] (Configuration of the liquid supply unit 140) The liquid supply unit 140 has the function of supplying a cleaning liquid (cleaning solution) to the surface of the substrate W. As the cleaning solution, for example, pure water or a liquid mainly composed of water can be used. In this embodiment, pure water is used as the cleaning solution.

[0045] The liquid supply unit 140 includes a first support frame 141, a second support frame 142, and a supply nozzle 143. The first support frame 141 and the second support frame 142 are each cylindrical members, and the second support frame 142 is inserted through the hollow portion of the first support frame 141. The second support frame 142 is connected to a drive mechanism (not shown) and is capable of rotating inside the first support frame 133a. That is, the second support frame 142 is rotatable around the rotation axis 12 relative to the first support frame 141.

[0046] Thus, the liquid supply unit 140 has a second support frame 142 and a supply nozzle 143 fixed to the second support frame 142 that rotates around the rotation axis 12. In other words, the liquid supply unit 140 is configured so that the liquid discharge port 143a of the supply nozzle 143 can move between a retracted position where it does not overlap with the substrate W and a supply position located above the center of the substrate W.

[0047] The discharge cup section 150 includes a cylindrical member surrounding the rotating holding section 110 and serves to prevent the liquid discharged from the surface of the substrate W from splashing into the surrounding area. The discharge cup section 150 can move vertically up and down by a lifting mechanism (not shown). In other words, when loading and unloading the substrate W to and from the rotating holding section 110, the discharge cup section 150 moves downward, and prior to the start of the cleaning process, the discharge cup section 150 moves upward. When the water film held on the surface of the substrate W is discharged by the rotation of the substrate W, the discharge cup section 150 catches the liquid that splashes into the surrounding area. Although not shown, the discharge cup section 150 has a container-type structure that contains the cleaning liquid that flows down after hitting the inner wall surface located on the side of the rotating holding section 110, and the accumulated cleaning liquid can be discharged from an outlet provided at the bottom.

[0048] The control unit 160 controls the operation of the substrate cleaning device 100. Specifically, the control unit 160 controls the cleaning process on the substrate W by controlling the rotating holding unit 110, the first cooling medium supply unit 120, the second cooling medium supply unit 130, and the liquid supply unit 140. The control unit 160 includes an arithmetic unit 161 and a storage device 162. The arithmetic unit 161 is, for example, a CPU (Central Processing Unit). The storage device 162 is, for example, a ROM (Read Only Memory). In the control unit 160, the operation of each component of the substrate cleaning device 100 is controlled by the arithmetic unit 161 reading and executing a control program 162a stored in the storage device 162. The control program 162a includes a set of instructions for executing the cleaning process. However, the components constituting the control unit 160 are not limited to those shown in Figure 1. For example, the control unit 160 may include other components such as a large-capacity storage device such as a hard disk for storing various data, or a communication interface for communicating with an external network.

[0049] The cleaning process (substrate cleaning method) performed by the substrate cleaning apparatus 100 described above will be explained in detail below.

[0050] [Operation of the circuit board cleaning device 100] The substrate cleaning apparatus 100 of this embodiment cleans a substrate by a cleaning process using a freeze cleaning method. In the substrate cleaning method according to the first embodiment, first, the back side of the substrate W, which holds cleaning liquid on its surface, is cooled with a cooling gas to freeze the liquid film on the surface of the substrate W (first cooling process). Then, the surface of the frozen film obtained by freezing the liquid film is cooled with a cooling gas to further cool the frozen film held on the surface of the substrate W (second cooling process). In the substrate cleaning method according to this embodiment, by directly cooling the surface of the frozen film, the temperature decrease gradient (rate of temperature decrease) of the frozen film can be made larger than in conventional methods, the time required to lower the frozen film to a desired temperature can be shortened, and the throughput of the cleaning process can be improved.

[0051] Figure 3 is a flowchart showing the configuration of the substrate cleaning method performed by the substrate cleaning apparatus 100 according to the first embodiment. The substrate cleaning method shown in Figure 3 shows the flow from when the substrate W is loaded to when it is unloaded. Figure 4 is a diagram for explaining the relationship between the operation of the substrate cleaning apparatus 100 according to the first embodiment and the temperature of the cleaning liquid. The timing chart shown in the upper part of Figure 4 shows the ON / OFF operation 40 of the liquid supply unit 140, the ON / OFF operation 20 of the first cooling medium supply unit 120, and the ON / OFF operation 30 of the second cooling medium supply unit 130. The lower part of Figure 4 shows the change in the temperature of the cleaning liquid (pure water) over time. In the diagram shown in the lower part of Figure 4, the horizontal axis is time and the vertical axis is temperature. In the diagram shown in the lower part of Figure 4, P1 to P4 indicate the state of pure water. Specifically, P1 and P4 indicate that the pure water is in the liquid phase. P2 indicates that the pure water is in a solid-liquid mixed phase (a state in which solid and liquid phases are mixed). P3 indicates that pure water is in the solid phase.

[0052] The following describes the flow of the substrate cleaning process based on Figure 3, and, if necessary, uses Figure 4 to explain the operation of the substrate cleaning apparatus 100 and the state of the water film or ice film held on the surface of the substrate W.

[0053] As shown in Figure 3, when the cleaning process is started, the control unit 160 controls the first cooling medium supply unit 120 to supply cooling gas to the back surface of the substrate W (step S001 in Figure 3). Furthermore, the control unit 160 controls the liquid supply unit 140 to supply pure water to the surface of the substrate W (step S002 in Figure 3). At this time, the control unit 160 controls the rotation holding unit 110 to rotate the substrate W at a predetermined rotational speed (for example, about 100 rpm). Since pure water is supplied while the substrate W is rotating, the supplied pure water is continuously discharged to the outside of the substrate W.

[0054] Steps S001 and S002 described above are performed between times T0 and T1 as shown in Figure 4. In this embodiment, the process performed between times T0 and T1 is called the "preliminary process". As shown in the upper part of Figure 4, at time T0, the liquid supply unit 140 and the first cooling medium supply unit 120 are turned ON. In other words, in the preliminary process, pure water is supplied to the surface of the substrate W while the substrate W is being cooled. When the substrate W is cooled, frost may form on the surface due to the temperature difference. In this case, there is a risk that particles floating in the chamber may be taken up by the frost and adhere to the surface of the substrate W. In this embodiment, in the preliminary process, the substrate W is cooled from the back side while pure water is supplied to the front side, so that frost does not adhere to the surface of the substrate W. Note that in Figure 3, the order of steps S001 and S002 may be reversed, or they may be performed completely simultaneously.

[0055] When time T1 is reached, the control unit 160 controls the rotation holding unit 110 to reduce the rotation speed of the substrate W to a predetermined rotation speed (for example, about 30 rpm). At this point, a predetermined amount of pure water is held on the surface of the substrate W, and a water film of a predetermined thickness is formed on the surface of the substrate W. In this embodiment, the process performed between time T1 and time T2 is called the "water film formation process".

[0056] Next, the control unit 160 controls the liquid supply unit 140 to stop supplying pure water to the surface of the substrate W (step S003 in Figure 3). Step S003 is performed at time T2 as shown in Figure 4. As shown in the upper part of Figure 4, at time T2, the liquid supply unit 140 is in the OFF state, and the first cooling medium supply unit 120 remains in the ON state. Also, as shown in the lower part of Figure 4, when the supply of pure water by the liquid supply unit 140 stops, the temperature of the water film held on the surface of the substrate W decreases. For this reason, in this embodiment, the process performed between time T2 and time T6 is called the "cooling process".

[0057] When the cooling process begins, the control unit 160 controls the detection unit 132 to measure the temperature of the water film held on the surface of the substrate W. Specifically, in this embodiment, the temperature of the water film is measured using a radiation thermometer that constitutes the detection unit 132. Then, based on the detection result from the detection unit 132, the control unit 160 determines whether or not the water film held on the surface of the substrate W has frozen, that is, whether or not an ice film (frozen body) has been formed (step S004 in Figure 3). As will be described later, a significant temperature change is observed when pure water transitions from the liquid phase to the solid phase, so it is possible to detect whether or not an ice film has been formed by monitoring the temperature change of the water film.

[0058] Here, we will explain the change in the state of pure water from time T2 to time T4. As shown in the lower part of Figure 4, from time T2 onward, the temperature of the water film held on the surface of the substrate W decreases, and eventually the temperature falls below the freezing point (0°C in this embodiment), resulting in a supercooled state. If the cooling of the substrate W continues after the water film has become supercooled, the water film will eventually escape the supercooled state. In this embodiment, it is assumed that the water film escapes the supercooled state at time T3 when the temperature drops to S°C. However, the timing of escaping the supercooled state can vary, including stimulation by vibration and crystallization using foreign matter as a nucleation site. Once the pure water escapes the supercooled state, the temperature of the water film rises to 0°C, and it transitions to a state in which the solid phase and liquid phase are mixed (solid-liquid mixed phase). The period in the solid-liquid mixed phase (between time T3 and time T4) is actually very short, so there is no substantial difference between time T3 and time T4.

[0059] In freeze-cleaning methods, it is generally believed that foreign matter acts as a nucleus, causing the supercooled state to end and the transition to the solid phase to begin. In this embodiment, foreign matter adhering to the surface of the substrate W acts as a nucleus, causing the pure water to freeze, and the foreign matter is incorporated into the ice. Therefore, in the solid-liquid mixed phase after the supercooled state has ended, it is thought that the ice containing the foreign matter is suspended within the water film. In other words, foreign matter such as particles adhering to the surface of the substrate W can be separated from the surface of the substrate W.

[0060] In step S004 of Figure 3 above, based on the detection result of the detection unit 132 (measurement result of the water film temperature), it is possible to detect whether or not the pure water has escaped the supercooled state by the rise in the water temperature. In other words, the determination result of the control unit 160 will be NO until at least time T3 has elapsed. After that, the water film held on the surface of the substrate W freezes completely and becomes an ice film after passing through the solid-liquid mixed phase. When the water film held on the surface of the substrate W becomes a complete ice film, the temperature of the ice film starts to fall again (time T4). In this embodiment, when this example of a temperature change is detected (i.e., the temperature starts to fall again after the temperature rise when escaping the supercooled state), the determination result of the control unit 160 becomes YES.

[0061] As shown in Figure 3, if the determination result is YES, the control unit 160 controls the second cooling medium supply unit 130 to supply cooling gas to the surface of the ice film held on the surface of the substrate W (step S005 in Figure 3). Prior to starting the operation of the second cooling medium supply unit 130, the shut-off member 131 is moved to a close-proximity position closer to the substrate W between time T2 and time T4. In the timing chart shown in the upper part of Figure 4, the determination result of the control unit 160 becomes YES after a slight time lag from time T4 when the ice film is formed, and the second cooling medium supply unit 130 is turned ON. As described above, in this embodiment, three radiation thermometers are used as the detection unit 132 to measure the temperature at different locations on the substrate W. In step S004 in Figure 3, the control unit 160 outputs YES as the determination result when a decrease in temperature is detected by all radiation thermometers. The time lag mentioned above is the time from when the ice film is formed at time T4 until the measurement results of all radiation thermometers match.

[0062] As shown in the lower part of Figure 4, when the supply of cooling gas by the second cooling medium supply unit 130 is started, the temperature of the ice film held on the surface of the substrate W decreases further. In this embodiment, since the first cooling medium supply unit 120 remains ON, the back surface of the substrate W is continuously cooled. In other words, the ice film held on the surface of the substrate W is continuously cooled from the back side through the substrate W. In addition, the ice film is further cooled from the front side by the cooling gas supplied directly from the second cooling medium supply unit 130. Therefore, the cooling of the ice film can be accelerated compared to when the substrate W is cooled only from the back side by the first cooling medium supply unit 120.

[0063] When cooling by the second cooling medium supply unit 130 begins, the control unit 160 determines, based on the detection result from the detection unit 132, whether or not the ice film held on the surface of the substrate W has reached a predetermined temperature (step S006 in Figure 3). In this embodiment, the predetermined temperature is set to -20°C, but the example is not limited to this. In this embodiment, an example is shown in which the temperature of the ice film is determined based on the measurement result of a radiation thermometer, but the example is not limited to this. For example, it is also possible to use an imaging device as the detection unit 132 and determine whether or not the temperature of the ice film has reached a predetermined temperature by analyzing an image of the surface state of the ice film.

[0064] In step S006 shown in Figure 3, if the determination result of the control unit 160 is NO, the control unit 160 controls the detection unit 132 to periodically repeat the determination. If the determination result of the control unit 160 is YES, the control unit 160 turns off the first cooling medium supply unit 120 and the second cooling medium supply unit 130, stopping the supply of cooling gas to the substrate W and the ice film (step S007 in Figure 3). As shown in the upper part of Figure 4, in this embodiment, at time T5, it is determined that the determination result of step S006 is YES, and the operation of the first cooling medium supply unit 120 and the second cooling medium supply unit 130 is stopped. In step S007, when the first cooling medium supply unit 120 and the second cooling medium supply unit 130 are turned off, the supply of cooling gas is stopped, and the temperature of the ice film stops decreasing. After that, the temperature of the ice film gradually rises.

[0065] Next, the control unit 160 controls the liquid supply unit 140 to start supplying pure water to the surface of the ice film (step S008 in Figure 3). As shown in the upper part of Figure 4, in this embodiment, after the first cooling medium supply unit 120 and the second cooling medium supply unit 130 are turned OFF at time T5, the liquid supply unit 140 is turned ON at time T6 after a short time lag. As described above, in this embodiment, when stopping the operation of the second cooling medium supply unit 130, the shut-off member 131 is moved to a retracted position away from the substrate W. The aforementioned time lag is the time from when the shut-off member 131 is moved to the retracted position until the liquid outlet 143a of the liquid supply unit 140 moves above the center of the substrate W (liquid supply position).

[0066] When the supply of pure water from the liquid supply unit 140 begins, the ice film held on the surface of the substrate W comes into contact with the pure water and melts. At this time, the control unit 160 controls the rotation holding unit 110 to rotate the substrate W at a predetermined rotational speed (for example, about 100 rpm). Since pure water is supplied while the substrate W is rotating, the supplied pure water and the melted ice film, along with any foreign matter incorporated into the ice film, are discharged to the outside of the substrate W. In this embodiment, the process performed between time T6 and time T7 is called the "thawing process".

[0067] Once a predetermined time has elapsed since the start of the thawing process, the control unit 160 controls the liquid supply unit 140 to the OFF state, as shown in the upper part of Figure 4, and stops the supply of pure water to the substrate W (step S009 in Figure 3). In this embodiment, the liquid supply unit 140 is in the OFF state at time T7.

[0068] Finally, the control unit 160 controls the rotation holding unit 110 to rotate the substrate W at a predetermined rotational speed (for example, 1500 rpm) and perform spin drying (step S010 in Figure 3). When the substrate W is dry, the cleaning process is complete. The cleaning process described so far may be repeated multiple times. By performing the cleaning process described in this embodiment multiple times on the substrate W to be cleaned, further improvements in cleaning effectiveness can be achieved.

[0069] As described above, in the cleaning process using the freeze cleaning method according to this embodiment, an ice film is formed on the surface side by cooling from the back side of the substrate W, and after the ice film is formed, a cooling gas is supplied to the surface of the ice film to further cool it. According to this embodiment, by directly cooling the ice film formed on the surface of the substrate W to be processed (the surface to be cleaned), the ice film can be cooled faster than by cooling only from the back side of the substrate. As a result, the time required to lower the ice film to the desired temperature can be shortened, improving the throughput of the cleaning process. Furthermore, if a cooling gas is supplied directly to a liquid water film, the water film may evaporate or be pushed and moved by the cooling gas, which may result in an uneven thickness of the water film or exposure of a part of the substrate W. However, according to this embodiment, since a cooling gas is not supplied to the water film until the water film becomes an ice film, a uniform ice film can be formed on the substrate W.

[0070] (Variation 1) In this embodiment, an example was described in which the detection unit 132 is used to detect whether or not an ice film has formed, and based on the result, the second cooling medium supply unit 130 is turned ON to cool the ice film. However, this embodiment is not limited to this example. For example, it is also possible to experimentally determine in advance the time from when the supply of pure water is stopped until an ice film is formed (i.e., the time from time T2 to time T4 shown in the lower part of Figure 4), and then turn ON the second cooling medium supply unit 130 by time control.

[0071] Similarly, in this embodiment, the time from the start of cooling the ice film until the ice film cools to a predetermined set temperature (i.e., the time from time T4 to time T5 shown in the lower part of Figure 4) is determined experimentally in advance, and the first cooling medium supply unit 120 and the second cooling medium supply unit 130 can be turned OFF by time control.

[0072] According to this modified version, the detection unit 132 for detecting the state of the water film or ice film can be omitted, simplifying the configuration of the substrate cleaning apparatus 100. Furthermore, since there is no need to perform determination processes such as whether or not an ice film has formed or whether or not the ice film has reached a predetermined temperature, the control program 162a for executing the cleaning process can be further simplified.

[0073] (Modification 2) In this embodiment, an example in which the second cooling medium supply unit 130 has a shut-off member 131 has been described, but the embodiment is not limited to this example, and the shut-off member 131 can be omitted. That is, as long as it is possible to cool the ice film held on the surface of the substrate W uniformly, it is possible to cool the ice film without using the shut-off member 131. For example, multiple cooling gas outlets (supply nozzles) may be arranged facing the surface of the substrate W so that the cooling gas can be supplied uniformly to the surface of the ice film. In this case, it is preferable that the position of the first outlet that supplies cooling gas to the center of the substrate W is offset from the rotation axis 11 so that the cooling gas does not hit the center of the substrate W. It is also preferable that the positions of the second outlets that supply cooling gas to positions other than the center of the substrate W are evenly arranged surrounding the first outlet.

[0074] Although the configuration described in Modification 2 above was explained as a modification of the second cooling medium supply unit 130, similarly, the dispersion plate 122 may be omitted from the first cooling medium supply unit 120. That is, even if the cooling gas flows along the upper surface (inclined surface 121aa) of the upper portion 121a of the nozzle head unit 121 or the upper surface of the inner portion 112a of the cover unit 112, it is possible to uniformly cool the back surface of the substrate W. Alternatively, for example, multiple cooling gas outlets (supply nozzles) may be arranged facing the back surface of the substrate W to uniformly supply cooling gas to the back surface of the substrate W. In this case as well, it is preferable that the position of the first outlet that supplies cooling gas to the center of the substrate W is offset from the rotation axis 11 so that the cooling gas does not hit the center of the substrate W. It is also preferable that the positions of the second outlets that supply cooling gas to positions other than the center of the substrate W are evenly arranged surrounding the first outlets.

[0075] <Second Embodiment> In the second embodiment, an example is described in which the cleaning process performed by the substrate cleaning apparatus 100 has a different configuration from that of the first embodiment. Specifically, the cleaning process in this embodiment differs from the first embodiment in that the operation of the first cooling medium supply unit 120 is stopped when the cooling process by the second cooling medium supply unit 130 is performed. The basic configuration of the substrate cleaning apparatus is the same as that of the substrate cleaning apparatus 100 described in the first embodiment. Furthermore, since the basic configuration of the substrate cleaning method in this embodiment is the same as that of the substrate cleaning method in the first embodiment, the following description will focus on the differences and may omit redundant explanations.

[0076] Figure 5 is a flowchart showing the configuration of the substrate cleaning method performed by the substrate cleaning apparatus 100 according to the second embodiment. Figure 6 is a diagram illustrating the relationship between the operation of the substrate cleaning apparatus 100 according to the second embodiment and the temperature of the cleaning solution. The contents of the drawings shown in Figures 5 and 6 are the same as those of Figures 3 and 4 described in the first embodiment, except for the timing chart shown in the upper part of Figure 6, so no explanation is given. Specifically, in this embodiment, the configuration of the operation 20a of the first cooling medium supply unit 120 in the timing chart shown in the upper part of Figure 6 differs from that of the first embodiment.

[0077] When the cleaning process is started, the processes from steps S001 to S005 shown in Figure 5 are executed. Specifically, when an ice film is formed on the surface of the substrate W, the control unit 160 turns on the second cooling medium supply unit 130. These processes are the same as the processes from steps S001 to S005 in Figure 3 that were already described in the first embodiment, so their explanation is omitted.

[0078] Furthermore, the control unit 160 in this embodiment turns the first cooling medium supply unit 120 OFF, stopping the supply of cooling gas to the back surface of the substrate W (step S006 in Figure 5). In other words, in this embodiment, when an ice film is formed on the surface of the substrate W, the cooling process switches from indirect cooling via the substrate W to direct cooling of the surface of the ice film. As shown in the upper part of Figure 6, in this embodiment, after a slight time lag from the time T4 when it is determined that an ice film has been formed, the second cooling medium supply unit 130 is turned ON and the first cooling medium supply unit 120 is turned OFF.

[0079] Subsequently, the ice film held on the surface of the substrate W decreases in temperature due to cooling by the second cooling medium supply unit 130. At this time, since cooling on the back side of the substrate W is stopped, the temperature of the substrate W gradually rises. In other words, from time T4 onward, the temperature of the ice film decreases as time passes, so the volume of the ice film shrinks. On the other hand, the temperature of the substrate W increases as time passes, so the volume of the substrate W expands. Due to this difference in the state changes of the substrate W and the ice film, strain occurs at the contact surface between the two, and as the strain increases, cracks eventually appear in the ice film.

[0080] In view of the above-described phenomenon, in this embodiment, when cooling by the second cooling medium supply unit 130 is started, the control unit 160 determines whether or not cracks have occurred in the ice film held on the surface of the substrate W based on the detection result by the detection unit 132 (step S007 in Figure 5). In this embodiment, an imaging device is used as the detection unit 132, and the determination of whether or not cracks have occurred is made by analyzing the image captured of the surface state of the ice film. However, this is not the only example, and other methods can be applied as long as it is possible to detect that cracks have occurred on the surface of the ice film.

[0081] In step S007 shown in Figure 5, if the determination result of the control unit 160 is NO, the control unit 160 controls the detection unit 132 to periodically repeat the determination. If the determination result of the control unit 160 is YES, the control unit 160 turns off the second cooling medium supply unit 130 and stops supplying cooling gas to the ice film (step S008 in Figure 5). In Figure 5, the processes from step S009 to step S011 are the same as the processes from step S008 to step S010 in Figure 3 described in the first embodiment, so the explanation is omitted.

[0082] As described above, in the cleaning process using the freeze cleaning method according to this embodiment, an ice film is formed on the surface side by cooling from the back side of the substrate W (first cooling process), and after the formation of the ice film, cooling gas is supplied to the surface of the ice film to further cool it (second cooling process). When supplying cooling gas to the surface of the ice film, cooling from the back side of the substrate W is stopped to intentionally create strain between the substrate W and the ice film, causing cracks to form in the ice film. When cracks form in the ice film, foreign matter that was trapped in the ice film moves further away from the surface of the substrate W, improving the efficiency of removing foreign matter when removing the ice film. Therefore, even if the process proceeds to the next step (ice film thawing step) when cracks form in the ice film, as in this embodiment, it is possible to efficiently remove foreign matter. Thus, according to this embodiment, by intentionally causing cracks in the ice film formed on the surface of the substrate W to be processed (the surface to be cleaned), the time until proceeding to the next step (thawing step) can be significantly shortened, and the throughput of the cleaning process can be improved.

[0083] (Variation 1) In this embodiment, the detection unit 132 is used to detect whether or not an ice film has formed. However, similar to the first modification of the first embodiment, it is also possible to experimentally determine in advance the time from when the supply of pure water is stopped until an ice film is formed, and then turn on the second cooling medium supply unit 130 by time control.

[0084] Furthermore, in this embodiment, an example was described in which the detection unit 132 is used to detect whether or not cracks have occurred in the ice film, and the second cooling medium supply unit 130 is turned OFF based on the result. However, this embodiment is not limited to this example. For example, it is also possible to experimentally determine in advance the time from the start of cooling of the ice film until cracks occur in the ice film (i.e., the time from time T4 to time T5 shown in the lower part of Figure 6), and then turn OFF the second cooling medium supply unit 130 by time control.

[0085] According to this modified example, the detection unit 132 for detecting the state of the water film or ice film can be omitted, simplifying the configuration of the substrate cleaning apparatus 100. Furthermore, since there is no need to perform determination processes such as whether or not an ice film has formed or whether or not cracks have occurred in the ice film, the control program 162a for executing the cleaning process can be further simplified.

[0086] Although a substrate cleaning apparatus and substrate cleaning method according to one embodiment of the present invention have been described above with reference to the drawings, the present invention is not limited to the embodiments described above (including modified examples; the same applies hereinafter), and can be modified as appropriate without departing from the spirit of the present invention. For example, any additions, deletions, or design changes made by a person skilled in the art based on each embodiment are also included in the scope of the present invention, as long as they retain the gist of the present invention. Furthermore, the configurations of each embodiment described above can be combined as appropriate as long as they do not contradict each other, and technical matters common to each embodiment are included in each configuration even without explicit description.

[0087] Any effects or benefits other than those brought about by the embodiments described above, if they are clear from the description herein or easily predictable to a person skilled in the art, are naturally considered to be brought about by the present invention. [Explanation of symbols]

[0088] 11, 12... Rotating shaft, 100... Substrate cleaning device, 110... Rotating holding part, 111... Base part, 111a... Cylindrical part, 111b... Protruding part, 112... Cover part, 112a... Inner part, 112aa... Opening, 112b... Outer part, 113... Holding part, 113a... Main body part, 113b... Pin, 114... Drive part, 114a... Opening, 120... First cooling medium supply part, 121... Nozzle head part, 121a... Upper part, 121aa... Inclined surface, 121ab... Groove part, 121b... Lower part, 121c... Through hole, 122... Dispersion plate, 122a... Through hole, 123... Cooling medium supply device 130...Second cooling medium supply unit, 131...Blocking member, 131a...Through hole, 131b...Opening, 131c...Opening end, 132...Detection unit, 133...Lifting mechanism, 133a...First support frame, 133b...Second support frame, 133c...Support arm, 133d...Connecting unit, 133da...Through hole, 134...Cooling medium supply device, 140...Liquid supply unit, 141...First support frame, 142...Second support frame, 143...Supply nozzle, 143a...Liquid discharge port, 150...Discharge cup unit, 160...Control unit, 161...Calculation unit, 162...Storage device, 162a...Control program

Claims

1. A rotating holding part that holds the substrate, A liquid supply unit that supplies liquid to the first surface of the substrate, A first cooling medium supply unit supplies a first cooling medium toward the second surface of the substrate opposite to the first surface, A second cooling medium supply unit that supplies a second cooling medium toward the first surface, A control unit that controls the rotating holding unit, the first cooling medium supply unit, the second cooling medium supply unit, and the liquid supply unit to perform a cleaning process on the substrate, Equipped with, The aforementioned cleaning process is A first cooling process involves supplying the first cooling medium toward the second surface to freeze the liquid on the first surface and form a frozen body, A second cooling process is performed to further cool the frozen body by supplying the second cooling medium toward the first surface, A circuit board cleaning device, including a substrate cleaning device.

2. The substrate cleaning apparatus according to claim 1, wherein during the second cooling process, the first cooling medium supply unit stops supplying the first cooling medium toward the second surface.

3. The substrate cleaning apparatus according to claim 1 or 2, wherein the cleaning process further includes a melting process in which the liquid supply unit supplies the liquid to the frozen body after the second cooling process to melt the frozen body.

4. The substrate cleaning apparatus according to claim 3, wherein the melting process is performed when cracks occur in the frozen body during the second cooling process.

5. The second cooling medium supply unit includes a blocking member that is supported so as to be able to move up and down so as to face the first surface, The substrate cleaning apparatus according to claim 1 or 2, wherein the second cooling medium is supplied toward the first surface via the blocking member.

6. The substrate cleaning apparatus according to claim 5, wherein the blocking member is a plate-shaped member having a through hole for supplying the second cooling medium.

7. The substrate cleaning apparatus according to claim 5, wherein the second cooling medium supply unit further includes a detection unit attached to the blocking member for detecting the formation of the frozen body.

8. The substrate cleaning apparatus according to claim 7, wherein the detection unit is a radiation thermometer.

9. The substrate cleaning apparatus according to claim 1 or 2, wherein the first cooling medium and the second cooling medium are cooling mediums at the same temperature.

10. A liquid is supplied to the first surface of the substrate. By supplying the first cooling medium toward the second surface of the substrate opposite to the first surface, the liquid on the first surface is frozen to form a frozen body. A substrate cleaning method comprising further cooling the frozen body by supplying a second cooling medium toward the first surface.

11. The substrate cleaning method according to claim 10, wherein when the frozen body is further cooled, the supply of the first cooling medium toward the second surface is stopped.

12. The substrate cleaning method according to claim 10 or 11, further comprising cooling the frozen body and then supplying the liquid to the frozen body to melt the frozen body.

13. The substrate cleaning method according to claim 12, wherein the thawing of the frozen body is performed when cracks occur in the frozen body during cooling.

14. The substrate cleaning method according to claim 10 or 11, wherein supplying the second cooling medium toward the first surface is performed when the frozen body is formed on the first surface.

15. The substrate cleaning method according to claim 14, wherein the formation of the frozen body is determined by the measurement result of a radiation thermometer.

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