Wet Process Equipment

Abstract

To provide a wet processor which can perform wet processing on both surfaces of a processing target object.SOLUTION: The wet processor includes: a stage (19); a plurality of supporting pins (20a, 20b) protruding from the stage (19) to an upper direction and supporting the outer edge of the processing target object (W) in positions distant from one another in a circumferential direction; a rotation driving unit for rotating the stage (19) around a vertically extending axial of rotation; a supply nozzle (22) for supplying, from the above, a processing solution on the processing target object (W) supported by the supporting pins (20a, 20b); and a holding ring (29) placed on the stage (19) to surround the supporting pins (20a, 20b) below the processing target object (W).SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a wet process device in a semiconductor process. [Background technology]

[0002] In recent years, a minimal fab system has been proposed as a semiconductor device manufacturing line that is based on creating one device per 0.5-inch (half-inch) wafer.To achieve this, the manufacturing process is configured with multiple portable unit processing devices, and by making it easy to rearrange these multiple unit processing devices in a flow ship or job shop, it can be used appropriately for ultra-low-volume production and high-mix production.

[0003] As a wet process device, specifically a cleaning device, employed in a minimal fab system, Patent Document 1 discloses a spin cleaning device that drops cleaning liquid onto a wafer while rotating a stage on which the wafer is placed. This type of spin cleaning device has the advantage of being able to retain cleaning liquid on the surface (top surface) of the wafer by utilizing surface tension, thereby enabling efficient wafer cleaning with a small amount of cleaning liquid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-106688 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the spin cleaning apparatus described in Patent Document 1 is unable to keep the cleaning liquid on the backside (lower surface) of the wafer placed on the stage for a long time, which poses a problem in that the backside of the wafer cannot be properly cleaned.

[0006] The present invention has been made in view of the above-mentioned state of the art, and an object of the present invention is to provide a wet processing apparatus capable of efficiently wet processing both sides of an object to be processed. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a processing apparatus including: a stage; a plurality of support pins each protruding upward from the stage and supporting an outer edge of a processing object at circumferentially spaced positions; a rotation drive unit that rotates the stage about a rotation axis extending in a vertical direction; and a processing object supported by the plurality of support pins. Surface and a supply nozzle for supplying a processing liquid from above, the wet processing apparatus further comprising: a holding ring placed on the stage below the object to be processed so as to surround the plurality of support pins. In order to hold the processing solution on the back surface of the object to be processed, a space surrounded by the back surface of the object to be processed and the holding ring is provided. It is characterized by: [Effects of the Invention]

[0008] According to the present invention, a wet processing apparatus capable of efficiently wet processing both sides of an object to be processed can be obtained. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a spin cleaning apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic side view of the interior of the process chamber. [Figure 3] FIG. 2 is a schematic plan view of the interior of a process chamber. [Figure 4] FIG. 10 shows a retaining ring. [Figure 5] FIG. 2 is a control block diagram of the spin cleaning device. [Figure 6] FIG. 10 is a diagram showing the state of the cleaning liquid supplied to the wafer. [Figure 7] 10 is a diagram showing the relationship between the amount of cleaning liquid supplied by the supply nozzle per time and the retention time of the cleaning liquid on both surfaces of the wafer. FIG. [Figure 8]FIG. 10 is a diagram showing the relationship between the rotation speed of the spin table and the retention time of the cleaning liquid on both sides of the wafer. [Figure 9] 10A and 10B are a schematic side view and a schematic plan view of the inside of a process chamber according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a spin cleaning apparatus 1 according to this embodiment. The spin cleaning apparatus 1 (wet process apparatus) is an apparatus that cleans the front and back surfaces of a wafer W (workpiece) (for example, by removing resist, etching, or removing adhering residues). The spin cleaning apparatus 1 is also an apparatus that cleans the wafer W while rotating it. Furthermore, the spin cleaning apparatus 1 is a heating wet processing apparatus that supplies a cleaning liquid (processing liquid) to the wafer W while heating it.

[0011] The spin cleaning apparatus 1 is a minimal cleaning apparatus based on the minimal fab concept housed in a housing 10 of a pre-specified size. The minimal fab concept is optimal for the semiconductor manufacturing market, which produces a wide variety of products in small quantities, and is compatible with a variety of resource-saving, energy-saving, investment-saving, and high-performance fabs, realizing a minimal production system that minimizes production, as described in, for example, JP 2012-54414 A.

[0012] The wafer W has a predetermined size, for example, a disk-shaped outer shape with a diameter of 12.5 mm (half-inch size). However, the shape and size of the wafer W are not limited to the above example. The wafer W has a predetermined pattern formed thereon in advance and is in a state before cleaning. The wafer W may also be a bare silicon wafer from which the photoresist film has been removed.

[0013] The spin cleaning apparatus 1 has a housing 10 that is roughly rectangular parallelepiped in shape and whose longitudinal direction is the vertical direction. The housing 10 is structured to block both fine particles and gas molecules from entering the interior. A recess 11 that is recessed rearward and penetrates left and right is formed in the upper front portion of the housing 10. A front chamber 12 and a process chamber 13 are also formed inside the housing 10.

[0014] The front chamber 12 is a space formed directly below the recess 11. The process chamber 13 is a space formed on the rear side of the front chamber 12. Furthermore, an opening / closing door 14 is provided between the front chamber 12 and the process chamber 13. The opening / closing door 14 is configured to be movable between an open position that connects the front chamber 12 and the process chamber 13 and a closed position that blocks communication between the front chamber 12 and the process chamber 13. By setting the opening / closing door 14 to the open position, the wafer W can be moved between the front chamber 12 and the process chamber 13. Furthermore, by setting the opening / closing door 14 to the closed position, it is possible to prevent the intrusion of fine particles and gas molecules into the process chamber 13.

[0015] The antechamber 12 is a PLAD (Particle Lock Air-tight Docking) system that allows the wafer W accommodated in the minimal shuttle S to be loaded into and unloaded from the housing 10 without being exposed to the outside air. More specifically, a docking port 15 is formed between the recess 11 and the antechamber 12 (on the top surface of the antechamber 12). The docking port 15 is a port for loading and unloading the wafer W into and from the spin cleaning apparatus 1. The minimal shuttle S accommodating the wafer W is placed on the docking port 15. The minimal shuttle S is composed of a lid and a bottom that can be attached and detached in the vertical direction. By joining the lid and the bottom with the wafer W accommodated therein, it is possible to prevent the intrusion of fine particles and gas molecules into the interior.

[0016] An elevator device 16 is also provided in the anterior chamber 12. The elevator device 16 raises and lowers the wafer W within the anterior chamber 12. More specifically, the elevator device 16 separates the bottom body supporting the wafer W from the lid body and lowers it, and also raises the bottom body supporting the wafer W and joins it to the lid body.

[0017] Furthermore, a transfer device 17 is provided in the front chamber 12. The transfer device 17 transfers the wafer W between the elevator device 16 and a stage 19, which will be described later. The transfer device 17 includes a transfer arm 17a that slides (extends and contracts) in the front and rear directions between the front chamber 12 and the process chamber 13. More specifically, the transfer arm 17a receives the wafer W from a bottom body supported by the lowered elevator device 16, enters the process chamber 13 from the front chamber 12, and places the wafer W on support pins 20a to 20d of the stage 19. The transfer arm 17a also receives the wafer W from the support pins 20a to 20d, exits the process chamber 13 to the front chamber 12, and transfers the wafer W to the bottom body supported by the elevator device 16.

[0018] The process chamber 13 is a space where the wafer W transferred by the transfer device 17 is cleaned. A flow of nitrogen gas (downflow) from above to below is formed in the process chamber 13. Furthermore, by placing the opening / closing door 14 in the closed position, the process chamber 13 is maintained at a positive pressure relative to the antechamber 12. This prevents fine particles and gas molecules from entering the process chamber 13 while the wafer W is being cleaned.

[0019] Fig. 2 is a schematic side view of the inside of process chamber 13. Fig. 3 is a schematic plan view of the inside of process chamber 13. As shown in Figs. 1 to 3, in process chamber 13, a spin table 18, a stage 19, a plurality of support pins 20a, 20b, 20c, and 20d, a chuck 21, and a supply nozzle 22 are arranged.

[0020] Spin table 18 is supported inside process chamber 13 so as to be rotatable about a rotation axis extending in the vertical direction. A stage 19 is provided at the center of the upper surface of spin table 18. Stage 19 is a circular portion that protrudes upward from the upper surface of spin table 18. A driving force from a rotation motor 23 (rotation drive unit) shown in FIG. 5 is transmitted to spin table 18, causing it to rotate together with stage 19 and support pins 20a-20d.

[0021] 5 is built into the spin table 18. The lamp heater 24 heats the wafer W (more specifically, the interface between the wafer W and the cleaning liquid) supported by the support pins 20a to 20d. For example, a xenon lamp or the like can be used as the lamp heater 24.

[0022] The support pins 20a to 20d protrude upward from the upper surface of the stage 19. The support pins 20a to 20d are arranged at predetermined intervals (90° intervals in this embodiment) in the circumferential direction. The support pins 20a to 20d have notches cut out from the inner sides of their tips (upper ends) to form step portions 25a, 25b, 25c, and 25d. The outer edge of the wafer W is placed on the step portions 25a to 25d, whereby the wafer W is supported by the support pins 20a to 20d. However, the number of support pins 20a to 20d is not limited to four, and may be three, or five or more.

[0023] Chuck 21 is disposed on spin table 18 between adjacent support pins 20c and 20d. Chuck 21 is configured to be able to move toward and away from wafer W supported by support pins 20a to 20d. When chuck 21 comes into contact with wafer W, wafer W is fixed on support pins 20a to 20d. When chuck 21 moves away from wafer W, the wafer W is released from the fixation, and wafer W can be removed from support pins 20a to 20d.

[0024] Supply nozzle 22 is configured to be movable up and down above stage 19. The tip surface (bottom surface) of supply nozzle 22 is circular and has a diameter equal to or slightly larger than the diameter of wafer W. Supply nozzle 22 also has a supply path 22a that opens to the bottom surface. Supply nozzle 22 supplies a cleaning liquid (e.g., chemical solution, ultrapure water) and nitrogen gas, which are examples of processing liquids, to wafer W supported by support pins 20a to 20d through supply path 22a. Supply nozzle 22 also includes a built-in oscillator 26 (see FIG. 5) that vibrates supply nozzle 22 at a high frequency (e.g., 1 MHz).

[0025] Examples of chemical solutions include hydrofluoric acid, ozone water, a mixture of sulfuric acid and hydrogen peroxide, and an aqueous potassium hydroxide solution. Supply nozzle 22 may supply the chemical solution, ultrapure water, and nitrogen gas through a single supply path 22a. Alternatively, supply nozzle 22 may have multiple supply paths for supplying the chemical solution, ultrapure water, and nitrogen gas, respectively.

[0026] The housing 10 also accommodates a cleaning liquid tank 27 for storing the cleaning liquid used to clean the wafer W, a waste liquid tank 28 for storing the cleaning liquid (hereinafter referred to as "waste liquid") discharged from the process chamber 13 after cleaning the wafer W, an exclusion adsorption tower (not shown) for removing exhausted harmful gases, a drive system (not shown) such as motors and air cylinders for driving each part, and a control device 30 (see Figure 5) for controlling the operation of the spin cleaning device 1.

[0027] 2 and 3, a retaining ring 29 is detachably attached to the stage 19. The retaining ring 29 is placed on the stage 19 so as to surround the support pins 20a to 20d. This brings the lower surface of the retaining ring 29 into surface contact with the upper surface of the stage 19. Meanwhile, a vertical gap is formed between the back surface of the wafer W placed on the stepped portions 25a to 25d and the upper surface of the retaining ring 29, allowing the transfer arm 17a to enter. For example, as shown in FIG. 6, the thickness of the retaining ring 29 is set to 1 mm, and the vertical gap between the wafer W and the retaining ring 29 is set to 3 mm. However, the specific dimensions are not limited to those shown in FIG. 6.

[0028] Fig. 4 is a diagram showing the retaining ring 29. As shown in Fig. 4, the retaining ring 29 has a generally ring-shaped outer shape. The retaining ring 29 is made of a material including, for example, polyvinylidene fluoride rubber (FKM), synthetic quartz, or polytetrafluoroethylene (PTFE). However, the material constituting the retaining ring 29 is not limited to the above examples.

[0029] Retaining ring 29 has an opening 29a formed through its center in the thickness direction. The inner peripheral surface of retaining ring 29 (i.e., the shape of opening 29a) is a rectangle with rounded vertices. The area between the curved vertices extends linearly (i.e., a flat surface). As shown in FIG. 3, retaining ring 29 is placed on stage 19 so that support pins 20a to 20d contact the curved vertices. Retaining ring 29 has openings 29a of a shape corresponding to the number of support pins 20a to 20d. That is, if there are five support pins, the retaining ring has a pentagonal opening with curved vertices.

[0030] The outer peripheral surface of retaining ring 29 is circular. However, as shown in Fig. 4(A), a notch 29b is formed in a position (i.e., part of the circumferential direction) that faces chuck 21 when retaining ring 29 is placed on stage 19 to avoid interference with chuck 21. As shown in Fig. 2, the outer dimensions of the largest part of retaining ring 29 (i.e., the outer dimensions avoiding the position of notch 29b) are greater than the diameter of stage 19.

[0031] 4(A), the radial thickness of retaining ring 29 varies at different positions in the circumferential direction. More specifically, except for the portions where notches 29b are formed, retaining ring 29 is configured so that the radial thickness increases with increasing distance from the positions where it contacts support pins 20a-20d (i.e., the positions of the curved vertices). In other words, the contact area between retaining ring 29 and stage 19 increases with increasing distance from support pins 20a-20d in the circumferential direction.

[0032] 5 is a control block diagram of the spin cleaning apparatus 1. As shown in FIG. 5, the spin cleaning apparatus 1 includes a control device 30 having a central processing unit (CPU) 31 and a memory 32. The memory 32 is configured, for example, by a read-only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a combination of these. The control device 30 realizes the processing described below by having the CPU 31 read and execute program codes stored in the memory 32.

[0033] However, the specific configuration of the control device 30 is not limited to this, and may be realized by hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array).

[0034] The control device 30 controls the overall operation of the spin cleaning apparatus 1. More specifically, the control device 30 opens and closes the door 14, causes the elevator device 16 to raise and lower the wafer W, causes the transport device 17 to transport the wafer W, moves the chuck 21 back and forth, raises and lowers the supply nozzle 22, causes the supply nozzle 22 to supply cleaning liquid and nitrogen gas, causes the rotary motor 23 to rotate the spin table 18, causes the lamp heater 24 to heat the wafer W, and causes the vibrator 26 to vibrate the supply nozzle 22.

[0035] Next, the process of cleaning the wafer W by the spin cleaning apparatus 1 will be described with reference to Figures 2, 3, and 6. Figure 6 is a diagram showing the state of the cleaning liquid supplied to the wafer W. It is assumed that the retaining ring 29 is attached to the stage 19 before cleaning the wafer W.

[0036] 2(A) and 3(A), the control device 30 moves the transfer arm 17a, which has received the wafer W from the lifting device 16, toward the support pins 20a-20b. At this time, the door 14 is in the open position, the spin table 18 is stopped, the chuck 21 is retracted, and the supply nozzle 22 is raised.

[0037] 2(B) and 3(B), the control device 30 lowers the transfer arm 17a to a position where the wafer W faces the stepped portions 25a to 25d. As a result, the outer edge of the wafer W is placed on the stepped portions 25a to 25d and separated from the transfer arm 17a. As described above, the vertical gap between the back surface of the wafer W and the upper surface of the holding ring 29 is set to a size (e.g., 3 mm) that prevents interference between the lowered transfer arm 17a and the holding ring 29.

[0038] 2(C) and 3(C), the controller 30 causes the transfer arm 17a to withdraw from the process chamber 13, moves the open / close door 14 to the closed position, brings the chuck 21 into contact with the outer edge of the wafer W, lowers the supply nozzle 22, rotates the spin table 18, and heats the wafer W with the lamp heater 24. The controller 30 also generates a downflow of nitrogen gas within the process chamber 13 and creates a positive pressure within the process chamber 13. The controller 30 then supplies a cleaning liquid to the wafer W from the supply nozzle 22, which is vibrated by the vibrator 26.

[0039] 6, the distance between the surface of wafer W and the bottom surface of supply nozzle 22 is set to, for example, 0.8 mm to 3.0 mm. Then, controller 30 supplies the chemical solution from supply nozzle 22 to wafer W while rotating spin table 18 at a low speed (for example, 50 rpm or less). Controller 30 supplies 0.6 ml to 0.8 ml of chemical solution from supply nozzle 22 over one second, for example, once every 10 seconds.

[0040] 6, the chemical liquid is held by surface tension between the front surface (upper surface) of the wafer W and the lower surface of the supply nozzle 22. The space between the rear surface (lower surface) of the wafer W and the upper surface of the stage 19 is filled with the chemical liquid blocked by the retaining ring 29. As a result, both surfaces of the wafer W are cleaned simultaneously.

[0041] Furthermore, by rotating the spin table 18 at a low speed, the chemical solution on both sides of the wafer W is stirred and slowly leaks outward in the radial direction. More specifically, the chemical solution held between the back surface of the wafer W and the holding ring 29 is slowly discharged through the gap between the upper surface of the stage 19 and the lower surface of the holding ring 29.

[0042] The control device 30 continues this state for, for example, about 20 to 45 seconds. Next, the control device 30 rotates the spin table 18 at high speed (for example, 1000 rpm or more) to blow off the chemical liquid on both the top and bottom surfaces of the wafer W by centrifugal force. Next, the control device 30 replaces the chemical liquid with ultrapure water and executes the above-mentioned process. As a result, the chemical liquid remaining on both surfaces of the wafer W is washed away.

[0043] Next, while rotating spin table 18 at high speed, controller 30 sprays nitrogen gas onto wafer W from supply nozzle 22. This dries wafer W. Furthermore, controller 30 uses transfer device 17 and lifting device 16 to remove wafer W supported by support pins 20a to 20d from spin cleaning apparatus 1.

[0044] Next, the relationship between the amount of cleaning liquid supplied, the rotation speed of spin table 18, and the retention time of the cleaning liquid will be described with reference to Figures 7 and 8. Figure 7 is a diagram showing the relationship between the amount of cleaning liquid supplied per time by supply nozzle 22 and the retention time of the cleaning liquid on both surfaces of wafer W. Figure 8 is a diagram showing the relationship between the rotation speed of spin table 18 and the retention time of the cleaning liquid on both surfaces of wafer W. The retention time was measured visually as the time during which the cleaning liquid was retained on both surfaces of wafer W.

[0045] 7 and 8, the plot "●" indicates the experimental results for a combination of a hydrophilic wafer W and a retaining ring 29 made of PTFE. The plot "■" indicates the experimental results for a combination of a hydrophobic wafer W and a retaining ring 29 made of PTFE. The plot "×" indicates the experimental results for a combination of a hydrophilic wafer W and a retaining ring 29 made of FKM. The plot "♦" indicates the experimental results for a combination of a hydrophobic wafer W and a retaining ring 29 made of FKM.

[0046] 7, by setting the amount of cleaning liquid supplied by supply nozzle 22 per supply to 0.6 ml to 0.8 ml, the cleaning liquid is retained on both sides of wafer W for 13 seconds or more. In particular, with retaining ring 29 made of PTFE, the cleaning liquid is retained for 28 seconds or more, and the smaller the supply amount, the longer the retention time. In the experiment shown in FIG. 7, the rotation speed of spin table 18 is set to 10 rpm.

[0047] If the amount of cleaning liquid supplied is too small, the space between the front surface of the wafer W and the bottom surface of the supply nozzle 22 and the space enclosed by the back surface of the wafer W and the retaining ring 29 cannot be filled with cleaning liquid at the same time. On the other hand, if the amount of cleaning liquid supplied is too large, the surface tension limit is exceeded and the cleaning liquid suddenly overflows. That is, for a half-inch-sized wafer W, the predetermined amount of cleaning liquid that is sufficient to hold the cleaning liquid on the front surface of the wafer W by surface tension and to fill the space enclosed by the back surface of the wafer W and the retaining ring 29 is 0.6 ml to 0.8 ml. However, the optimum amount of cleaning liquid to be supplied varies depending on the material and diameter of the wafer W, the physical properties of the cleaning liquid, the material of the retaining ring 29, etc.

[0048] 8, by setting the rotation speed of the spin table 18 to 50 rpm or less, the cleaning liquid is retained on both sides of the wafer W for 13 seconds or more. In particular, with the retaining ring 29 made of PTFE, the cleaning liquid is retained for 20 seconds or more, and the retention time increases as the rotation speed decreases. In the experiment shown in FIG. 8, the amount of cleaning liquid supplied to the hydrophilic wafer W was set to 0.7 ml, and the amount of cleaning liquid supplied to the hydrophobic wafer W was set to 0.9 ml.

[0049] If the rotation speed of spin table 18 is too fast, the cleaning liquid will be quickly discharged due to centrifugal force. That is, the predetermined rotation speed at which the cleaning liquid remains in the space between the front surface of wafer W and the underside of supply nozzle 22 and in the space surrounded by the back surface of wafer W and retaining ring 29 is 50 rpm or less. On the other hand, if spin table 18 is stopped, the cleaning liquid will not be supplied uniformly over the entire wafer W, so it is desirable to supply the cleaning liquid while rotating spin table 18 at a low speed.

[0050] According to the above embodiment, by placing the retaining ring 29 on the stage 19 so as to surround the support pins 20a to 20d, the cleaning liquid can be retained not only on the front side of the wafer W but also on the back side of the wafer W. As a result, both sides of the wafer W can be cleaned simultaneously.

[0051] Another method for cleaning both surfaces of the wafer W is to immerse the wafer W in a storage container that stores a cleaning liquid. However, this method requires a large space for installing the storage container and a large amount of cleaning liquid. Another method for cleaning both surfaces of the wafer W is to clean the front surface of the wafer W, then flip the wafer W and clean the back surface. However, this method requires a mechanism for flipping the wafer W, and it takes time to clean both surfaces of the wafer W.

[0052] That is, according to the above embodiment, the spin cleaning apparatus 1 for cleaning both sides of the wafer W can be realized with a simple configuration and cleaning liquid can be saved. Furthermore, since both sides of the wafer W can be cleaned simultaneously, the throughput of the spin cleaning apparatus 1 is improved.

[0053] 4A, the contact area between stage 19 and retaining ring 29 increases with increasing distance from the position where it contacts support pins 20a to 20d. This reduces the rate at which cleaning liquid leaks out from the gap between stage 19 and retaining ring 29.

[0054] Furthermore, according to the above embodiment, by setting appropriate values ​​for the amount of cleaning liquid supplied by supply nozzle 22 per supply and the rotation speed of spin table 18, it is possible to lengthen the time that cleaning liquid remains on both sides of wafer W. As a result, wafer W can be properly cleaned with fewer supplies, which saves cleaning liquid and improves the throughput of spin cleaning apparatus 1.

[0055] Furthermore, according to the above embodiment, the interface between the wafer W and the cleaning liquid is heated by the lamp heater 24, thereby maintaining the cleaning liquid in a temperature range that provides a high cleaning effect. Also, by vibrating the cleaning liquid with the vibrator 26, the cleaning liquid can be uniformly distributed over the entire area of ​​the wafer W, and the cleaning liquid is uniformly heated. Furthermore, the retaining ring 29 made of PTFE bends due to an increase in temperature, thereby reducing the gap between the stage 19 and the retaining ring 29, and further extending the retention time of the cleaning liquid.

[0056] [Variations] A modification of the above embodiment will be described with reference to Figure 9. Figure 9 is a schematic side view and a schematic plan view of the interior of the process chamber 13 according to the modification. Components common to the above embodiment are given the same reference numerals, and detailed description will be omitted, with the differences being mainly described. The modification shown in Figure 9 differs from the above embodiment in that an O-ring 40 is further attached, but is common to the above embodiment in other respects.

[0057] The O-ring 40 is disposed along the outer circumferential surface of the stage 19 so as to surround the stage 19. The thickness of the O-ring 40 is set to be equal to or slightly greater than the protruding height of the stage 19. Furthermore, the outer dimensions of the O-ring 40 are set to be larger than those of the retaining ring 29.

[0058] That is, O-ring 40 contacts the underside of retaining ring 29 around the entire circumference of retaining ring 29. This makes it possible to retain cleaning liquid that leaks out from between the upper surface of stage 19 and the lower surface of retaining ring 29. As a result, the retention time of cleaning liquid on the backside of wafer W can be further extended.

[0059] Furthermore, the present invention is not limited to a spin cleaning apparatus for cleaning wafers W, but can be applied to any wet process apparatus that wet processes a workpiece using a processing liquid in a semiconductor process. Other examples of wet process apparatuses include etching apparatuses and developing apparatuses. Other examples of processing liquids include etching liquids and developing liquids.

[0060] The above describes an embodiment of the present invention. However, the present invention is not limited to the above embodiment and includes various modifications. For example, the above embodiment has been described in detail to clearly explain the present invention, and is not necessarily limited to an embodiment including all of the described configurations. Furthermore, it is possible to replace part of the configuration of this embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of this embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of this embodiment with other configurations. [Explanation of symbols]

[0061] 1...spin cleaning apparatus (wet process apparatus), 10...casing, 11...recess, 12...anteroom, 13...process chamber, 14...opening / closing door, 15...docking port, 16...lifting device, 17...transfer device, 17a...transfer arm, 18...spin table, 19...stage, 20a, 20b, 20c, 20d...support pin, 21...chuck, 22...supply nozzle, 22a...supply path, 23...rotary motor, 24...lamp heater, 25a, 25b, 25c, 25d...step portion, 26...vibrator, 27...cleaning liquid tank, 28...waste liquid tank, 29...retaining ring, 29a...opening, 29b...notch, 30...control device, 31...CPU, 32...memory, 40...O-ring

Claims

1. The stage and a plurality of support pins each protruding upward from the stage and supporting the outer edge of the workpiece at circumferentially spaced positions; a rotation drive unit that rotates the stage around a rotation axis that extends in the vertical direction; a supply nozzle that supplies a processing liquid from above to a surface of the workpiece supported by the plurality of support pins, a retaining ring placed on the stage so as to surround the plurality of support pins below the object to be processed; A wet process device characterized by having a space surrounded by the back surface of the workpiece and the retaining ring for retaining a processing solution on the back surface of the workpiece.

2. 2. The wet process apparatus according to claim 1, The wet process apparatus is characterized in that the holding ring has a radial thickness that increases with increasing distance from the position where the holding ring contacts the support pin.

3. 3. The wet process apparatus according to claim 1, The wet process apparatus is characterized in that the retaining ring contains vinylidene fluoride rubber, synthetic quartz, or polytetrafluoroethylene.

4. The wet process apparatus according to any one of claims 1 to 3, A wet process apparatus comprising: an O-ring disposed in contact with the lower surface of the retaining ring and having an outer dimension larger than that of the retaining ring.

5. The wet process apparatus according to any one of claims 1 to 4, The supply nozzle is held on the surface of the workpiece by surface tension, and supplies a predetermined amount of processing liquid to fill the back surface of the workpiece and a space surrounded by the retaining ring.

6. The wet process apparatus according to any one of claims 1 to 5, The wet process apparatus is characterized in that the rotation drive unit rotates the stage at a predetermined rotation speed so that the processing liquid remains in the space between the workpiece and the supply nozzle, and in the back surface of the workpiece and the space surrounded by the retaining ring.

7. The wet process apparatus according to any one of claims 1 to 6, A wet process apparatus comprising a heating unit for heating the workpiece supported by the support pins.

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