Cleaning method of substrate processing device and substrate processing system

Abstract

The present invention provides a cleaning method and a substrate processing system for a substrate processing device. In the cleaning method for a substrate processing device, the substrate processing device is capable of performing a drying process, wherein the drying process causes a substrate whose surface is wetted by a liquid to contact a supercritical fluid to dry the substrate. The cleaning method for a substrate processing device includes: diffusing a cleaning fluid within the substrate processing device, wherein the cleaning fluid is a mixture of the supercritical fluid and a solvent containing polar molecules and having a lower boiling point than the liquid; and discharging the cleaning fluid from the interior of the substrate processing device after the cleaning fluid has diffused. The present invention can suppress the adhesion of particles to the substrate during a drying process using a supercritical fluid.

Description

Technical Field

[0001] The invention relates to a cleaning method for a substrate processing device and a substrate processing system. Background Art

[0002] Conventionally, there has been known a technique for drying a substrate such as a semiconductor wafer by bringing the substrate, whose surface is wetted by the liquid, into contact with a treatment fluid in a supercritical state in a drying step after the surface of the substrate is treated with a liquid.

[0003] Patent document 1 discloses a substrate processing apparatus including: a chamber for accommodating a substrate; a supply passage connected to the chamber for supplying a supercritical fluid to a surface of the substrate; and a discharge passage connected to the chamber for discharging the supercritical fluid in the chamber.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-251550 Summary of the Invention

[0007] Technical problem to be solved by the invention

[0008] The present invention provides a cleaning method for a substrate processing apparatus and a substrate processing system capable of suppressing adhesion of particles to a substrate during a drying process using a supercritical fluid.

[0009] Technical solutions to technical problems

[0010] In a cleaning method for a substrate processing device according to one embodiment of the present invention, the substrate processing device is capable of performing a drying treatment, wherein the drying treatment brings a substrate whose surface is wetted by a liquid into contact with a supercritical fluid to dry the substrate. The cleaning method for the substrate processing device includes: a step of diffusing a cleaning fluid inside the substrate processing device, wherein the cleaning fluid is a mixture of the supercritical fluid and a solvent containing polar molecules and having a lower boiling point than that of the liquid; and a step of discharging the cleaning fluid from the interior of the substrate processing device after the cleaning fluid has diffused.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to suppress adhesion of particles to a substrate during a drying process using a supercritical fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing an overview of the cleaning process of the substrate processing system according to the first embodiment.

[0014] Figure 2It is a diagram showing a schematic configuration of a substrate processing system according to the first embodiment.

[0015] Figure 3 It is a cross-sectional view showing the structure of the cleaning processing unit.

[0016] Figure 4 It is an external perspective view showing the structure of the drying process unit.

[0017] Figure 5 It is a diagram showing an example of the overall system configuration of the drying processing unit in the first embodiment.

[0018] Figure 6 This is a block diagram showing the functional configuration of the control device.

[0019] Figure 7 This is a diagram for explaining the drying principle of IPA and is an enlarged cross-sectional view schematically showing a pattern on a wafer.

[0020] Figure 8 This is a flowchart showing the cleaning process of the drying process unit in the first embodiment.

[0021] Figure 9A This is a diagram (part 1) showing an overview of the cleaning process of the drying process unit in the first embodiment.

[0022] Figure 9B This is a diagram (part 2) showing an overview of the cleaning process of the drying process unit in the first embodiment.

[0023] Figure 9C This is a diagram (part 3) showing an overview of the cleaning process of the drying process unit in the first embodiment.

[0024] Figure 10 It is a diagram showing a schematic configuration of a substrate processing system according to a second embodiment.

[0025] Figure 11 It is a diagram showing an example of the overall system configuration of a drying processing unit in the second embodiment.

[0026] Figure 12 This is a flowchart showing a cleaning process of the drying process unit in the second embodiment.

[0027] Figure 13A This is a diagram (part 1) showing an overview of the cleaning process of the drying process unit in the second embodiment.

[0028] Figure 13B This is a diagram (part 2) showing an overview of the cleaning process of the drying process unit in the second embodiment.

[0029] Figure 13CThis is a diagram (part 3) showing an overview of the cleaning process of the drying process unit in the second embodiment.

[0030] Figure 14A This is a perspective view showing an example of a jig.

[0031] Figure 14B This is a cross-sectional view showing an example of a jig.

[0032] Figure 15 This is a flowchart showing a cleaning process of the drying process unit in the third embodiment.

[0033] Figure 16A This is a diagram (part 1) showing an overview of a cleaning process of a drying process unit in a third embodiment.

[0034] Figure 16B This is a diagram (part 2) showing an overview of the cleaning process of the drying process unit in the third embodiment.

[0035] Figure 16C This is a diagram (part 3) showing an overview of the cleaning process of the drying process unit in the third embodiment.

[0036] Figure 16D This is a diagram (Part 4) showing an overview of the cleaning process of the drying process unit in the third embodiment.

[0037] Figure 17 It is a diagram showing an example of the overall system configuration of a drying processing unit in a fourth embodiment.

[0038] Figure 18 It is a diagram showing an outline of a cleaning process of a drying processing unit in the fourth embodiment.

[0039] Figure 19 It is a diagram showing an example of the overall system configuration of a drying processing unit in the fifth embodiment.

[0040] Description of Reference Numerals

[0041] 4 Control device

[0042] 16 Cleaning Processing Unit

[0043] 17 Drying unit

[0044] 19 Control Department

[0045] 70 Supercritical Fluid

[0046] 80, 180 cleaning fluid

[0047] 81 solvent

[0048] 100, 200 substrate processing system

[0049] W chip. DETAILED DESCRIPTION

[0050] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings, the same or corresponding components are denoted by the same or corresponding reference numerals, and repeated descriptions are omitted.

[0051] (First embodiment)

[0052] The first embodiment relates to a substrate processing system including a drying processing unit. The drying processing unit is an example of a substrate processing device.

[0053] <Overview of Cleaning Process of Substrate Processing System>

[0054] First, refer to Figure 1 , an overview of the cleaning process of the substrate processing system 100 according to the first embodiment will be described. Figure 1 1 is a diagram showing an overview of the cleaning process of the substrate processing system 100 according to the first embodiment.

[0055] In the substrate processing system 100 of the first embodiment (see Figure 2 ), in the drying processing unit 17 (refer to Figure 2 ), such as Figure 1 As shown in FIG. 1 , a drying process ( S1 ) using a supercritical fluid is repeatedly performed on a plurality of wafers. The drying process ( S1 ) will be described in detail later.

[0056] Here, in the cleaning process of the substrate processing system 100 of the first embodiment, the cleaning process (S2) is performed between repeated drying processes (S1) in the drying process unit 17 of the substrate processing system 100. The cleaning process (S2) includes a cleaning fluid diffusion process (S3) and an exhaust process (S4).

[0057] During the drying process (S1), particles sometimes adhere to the wafer. The present inventors conducted in-depth research to suppress the adhesion of particles. It was found that the particles are residues of the substance to be dried. It was also found that the substance to be dried is a polar molecule, while the supercritical fluid used for the drying process (S1) is a non-polar molecule. Therefore, the substance to be dried is insoluble in the supercritical fluid, and residue is generated. It was also found that by supplying a solvent for polar molecules together with the supercritical fluid to the drying process unit 17 to remove the residue from the inside of the drying process unit 17, it was possible to suppress the residue from adhering to the wafer.

[0058] Therefore, in the cleaning fluid diffusion process (S3), a cleaning fluid 80 (see Figure 9A 、 Figure 13B 、 Figure 16B ) diffuses in the drying processing unit 17. The cleaning fluid 80 diffused in the drying processing unit 17 can dissolve the residue of the substance to be dried in the drying processing unit 17.

[0059] In the subsequent exhaust process ( S4 ), the cleaning fluid 80 in which the residue has been dissolved is exhausted from the drying process unit 17 using a pump or the like.

[0060] That is, the cleaning fluid diffusion process (S3) and the exhaust process (S4) can remove the residue in the drying process unit 17. Therefore, the cleaning process (S2) of the substrate processing system 100 of the first embodiment can reduce the residue in the drying process unit 17 that performs the drying process (S1) using the supercritical fluid, thereby suppressing the adhesion of the residue to the wafer.

[0061] <Overview of Substrate Processing System>

[0062] Below, refer to Figure 2 , a schematic structure of the substrate processing system 100 according to the first embodiment is described. Figure 2 1 is a diagram showing a schematic configuration of a substrate processing system 100 according to Embodiment 1. Hereinafter, to clarify positional relationships, the X-axis, Y-axis, and Z-axis of a right-handed coordinate system orthogonal to each other are defined, with the positive Z-axis direction being the vertically upward direction.

[0063] like Figure 2 As shown, the substrate processing system 100 includes an inlet and outlet station 2 and a processing station 3. The inlet and outlet station 2 and the processing station 3 are arranged adjacent to each other.

[0064] The loading and unloading station 2 includes a carrier placement unit 11 and a conveying unit 12. A plurality of carriers C for storing a plurality of semiconductor wafers W (hereinafter referred to as wafers W) in a horizontal state are placed on the carrier placement unit 11.

[0065] The transport unit 12 is disposed adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and an interface 14 therein. The substrate transport device 13 includes a wafer holding mechanism for holding a wafer W. The substrate transport device 13 is movable in the horizontal and vertical directions and rotatable about a vertical axis, and uses the wafer holding mechanism to transport wafers W between the carrier C and the interface 14.

[0066] The processing station 3 is arranged adjacent to the conveying section 12. The processing station 3 includes a conveying section 15, a plurality of cleaning processing units 16 and a plurality of drying processing units 17. The plurality of cleaning processing units 16 and the plurality of drying processing units 17 are arranged side by side on both sides of the conveying section 15. Figure 2 The arrangement and number of the cleaning processing units 16 and the drying processing units 17 shown are merely examples, and are not limited to the arrangement and number shown in the figure.

[0067] The transport unit 15 is internally provided with a substrate transport device 18. The substrate transport device 18 includes a wafer holding mechanism for holding the wafer W. The substrate transport device 18 is movable in the horizontal and vertical directions and rotatable about a vertical axis. The wafer W is transported between the interface 14, the cleaning unit 16, and the drying unit 17 using the wafer holding mechanism.

[0068] The cleaning processing unit 16 performs a predetermined cleaning process on the wafer W transported by the substrate transport device 18. An example of the structure of the cleaning processing unit 16 will be described later.

[0069] The drying processing unit 17 performs the above-mentioned drying process on the wafer W that has been cleaned by the cleaning processing unit 16. An example of the structure of the drying processing unit 17 will be described later.

[0070] Furthermore, the substrate processing system 100 includes a control device 4. The control device 4 is, for example, a computer and includes a control unit 19 and a storage unit 20.

[0071] The control unit 19 includes a microcomputer and various circuits including a CPU (central processing unit), ROM (read-only memory), RAM (random access memory), input / output ports, etc. The CPU of the microcomputer reads and executes programs stored in the ROM to implement the control described below.

[0072] Furthermore, the program may be stored in a computer-readable storage medium and installed from the storage medium into the storage unit 20 of the control device 4. Examples of computer-readable storage media include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), and a memory card.

[0073] The storage unit 20 is realized by, for example, a semiconductor storage element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk.

[0074] In the substrate processing system 100 configured as described above, the substrate transport device 13 of the transport station 2 first removes a wafer W from the carrier C placed on the carrier placement portion 11 and places the removed wafer W on the delivery portion 14. The substrate transport device 18 of the processing station 3 removes the wafer W placed on the delivery portion 14 from the delivery portion 14 and transports it to the cleaning processing unit 16.

[0075] The wafer W sent to the cleaning unit 16 is cleaned by the cleaning unit 16 and then sent out of the cleaning unit 16 by the substrate transport device 18. The wafer W sent out of the cleaning unit 16 is sent to the drying unit 17 by the substrate transport device 18 and dried by the drying unit 17.

[0076] The wafer W dried in the drying unit 17 is transported from the drying unit 17 by the substrate transport device 18 and placed on the interface 14. The processed wafer W placed on the interface 14 is then returned to the carrier C of the carrier placement unit 11 by the substrate transport device 13.

[0077] <Overview of Cleaning Processing Unit>

[0078] Below, refer to Figure 3 , the schematic structure of the cleaning processing unit 16 is described. Figure 3 1 is a cross-sectional view showing the structure of the cleaning processing unit 16. The cleaning processing unit 16 is configured as a single-wafer type cleaning processing unit that cleans wafers W one by one by spin cleaning, for example.

[0079] like Figure 3 As shown, in the cleaning processing unit 16, a wafer W is held approximately horizontally by a wafer holding mechanism 25 disposed within an outer chamber 23 forming a processing space, and the wafer W is rotated by rotating the wafer holding mechanism 25 about a vertical axis. The cleaning processing unit 16 then positions a nozzle arm 26 above the rotating wafer W and cleans the front surface of the wafer W by supplying a chemical solution and a rinse solution in a predetermined order from a chemical solution nozzle 26a provided at the front end of the nozzle arm 26.

[0080] In the cleaning processing unit 16, a chemical liquid supply path 25a is also formed inside the wafer holding mechanism 25. The back surface of the wafer W is cleaned using the chemical liquid and rinse liquid supplied from the chemical liquid supply path 25a.

[0081] In the aforementioned wafer W cleaning process, for example, an alkaline chemical solution, such as SC1 (i.e., a mixture of ammonia and hydrogen peroxide solution), is first used to remove particles and organic contaminants. Subsequently, the wafer is rinsed with deionized water (DIW). Next, an acidic chemical solution, such as dilute hydrofluoric acid (DHF), is used to remove the native oxide film. Subsequently, the wafer is rinsed with DIW.

[0082] The various chemical solutions described above are received by the outer chamber 23 and the inner cup 24 disposed within the outer chamber 23 and are discharged through a drain port 23a provided at the bottom of the outer chamber 23 and a drain port 24a provided at the bottom of the inner cup 24. Furthermore, the atmosphere within the outer chamber 23 is discharged through an exhaust port 23b provided at the bottom of the outer chamber 23.

[0083] After the above-described rinsing process of the wafer W, liquid IPA (hereinafter referred to as "IPA liquid") is supplied to the front and back surfaces of the wafer W while the wafer holding mechanism 25 is rotated to replace the DIW remaining on both surfaces of the wafer W. Then, the rotation of the wafer holding mechanism 25 is slowly stopped.

[0084] The wafer W after the cleaning process is thus supplied with the IPA liquid 71 (see Figure 7 ) state (a liquid film of IPA liquid 71 is formed on the surface of the chip W), it is handed over to the substrate conveying device 18 by an unillustrated handover mechanism provided in the chip holding mechanism 25 and sent out from the cleaning processing unit 16.

[0085] Here, the IPA liquid 71 supplied to the surface of the chip W acts as an anti-drying liquid to prevent pattern degradation due to evaporation (gasification) of the liquid on the surface of the chip W during the action of transporting the chip W from the cleaning processing unit 16 to the drying processing unit 17 and during the action of transporting the chip W to the drying processing unit 17.

[0086] The wafer W having the cleaning process completed in the cleaning unit 16 and the IPA liquid 71 supplied to the surface is transported to the drying unit 17. Then, in the drying unit 17, the IPA liquid 71 on the surface of the wafer W is mixed with the supercritical fluid 70 of CO2 (see FIG. Figure 7 ) contact so that the IPA liquid 71 is dissolved in the supercritical fluid 70 of CO2 to remove it and perform a process of drying the wafer W.

[0087] <Overview of Drying Processing Unit>

[0088] Next, the configuration of the drying processing unit 17 will be described first, and then the overall configuration of the system in the drying processing unit 17 will be described. Figure 4 It is an external perspective view showing the structure of the drying processing unit 17 .

[0089] The drying processing unit 17 includes a main body 31, a holding plate 32, and a cover member 33. The shell-shaped main body 31 is formed with an opening 34 for loading and unloading wafers W. The holding plate 32 holds the wafers W to be processed horizontally. The cover member 33 supports the holding plate 32 and seals the opening 34 after the wafers W are loaded into the main body 31.

[0090] The main body 31 is a container having a processing space therein capable of accommodating a wafer W having a diameter of 300 mm, and is provided with supply ports 35A, 35B and an exhaust port 36 on its wall. The supply ports 35A, 35B and the exhaust port 36 are connected to the supercritical fluid 70 (see FIG. Figure 7 ) flow through the supply passage, which is provided on the upstream and downstream sides of the drying processing unit 17. The structural example of the supply passage will be described later.

[0091] The supply port 35A is connected to the side surface opposite to the opening 34 in the shell-shaped main body 31. In addition, the supply port 35B is connected to the bottom surface of the main body 31. Moreover, the discharge port 36 is connected to the lower side of the opening 34. Figure 4 Although two supply ports 35A and 35B and one discharge port 36 are shown in the figure, the numbers of the supply ports 35A and 35B and the discharge port 36 are not particularly limited.

[0092] Furthermore, fluid supply nozzles 37A and 37B and a fluid discharge nozzle 38 are provided inside the main body 31. The fluid supply nozzles 37A and 37B and the fluid discharge nozzle 38 are each formed with a plurality of openings.

[0093] The fluid supply nozzle 37A is connected to the supply port 35A and is provided adjacent to the side surface opposite to the opening 34 inside the shell-shaped main body 31. The plurality of openings formed in the fluid supply nozzle 37A face the opening 34 side.

[0094] The fluid supply nozzle 37B is connected to the supply port 35B and is provided at the center of the bottom surface inside the shell-shaped main body 31. The plurality of openings formed in the fluid supply nozzle 37B face upward.

[0095] The fluid discharge nozzle 38 is connected to the discharge port 36 and is provided adjacent to the side surface of the opening 34 and below the opening 34 within the shell-shaped main body 31. The plurality of openings formed in the fluid discharge nozzle 38 face the fluid supply nozzle 37A.

[0096] The fluid supply nozzles 37A and 37B supply the supercritical fluid 70 into the main body 31. The fluid discharge nozzle 38 guides the supercritical fluid 70 in the main body 31 to the outside of the main body 31 to discharge it. The supercritical fluid 70 discharged to the outside of the main body 31 through the fluid discharge nozzle 38 includes the IPA liquid 71 dissolved in the supercritical fluid 70 from the surface of the wafer W (see Figure 7 ).

[0097] The supercritical fluid 70 is supplied into the main body 31 from the openings of the fluid supply nozzles 37A and 37B configured as described above, and the supercritical fluid 70 is discharged from the main body 31 through the openings of the fluid discharge nozzle 38, thereby forming a laminar flow of the supercritical fluid 70 flowing in a prescribed direction around the chip W inside the main body 31.

[0098] The laminar flow of the supercritical fluid 70 flows from the fluid supply nozzle 37A, for example, above the wafer W, along the surface of the wafer W, toward the upper portion of the opening 34. Furthermore, the laminar flow of the supercritical fluid 70 changes direction above the opening 34 to flow downward, passes near the opening 34, and flows toward the fluid discharge nozzle 38.

[0099] In this laminar flow example, an opening (not shown) is formed inside the drying processing unit 17 between the wafer W on the holding plate 32 and the cover member 33 , and a laminar flow of the supercritical fluid 70 passes through the opening.

[0100] Furthermore, from the perspective of reducing the load applied to the wafer W when the supercritical fluid 70 is supplied to and discharged from the main body 31 , it is preferable to provide a plurality of fluid supply nozzles and a plurality of fluid discharge nozzles.

[0101] The drying unit 17 further includes a pressing mechanism (not shown). This pressing mechanism has the function of resisting the internal pressure generated by the supercritical fluid 70 in a supercritical state supplied to the processing space within the main body 31, pressing the cover member 33 against the main body 31 to seal the processing space. Furthermore, a heat insulating member, a belt heater, or the like may be provided on the surface of the main body 31 to maintain the supercritical fluid 70 supplied to the processing space at a predetermined temperature.

[0102] Below, refer to Figure 5 , the overall system structure of the drying processing unit 17 is described. Figure 5 It is a diagram showing an example of the overall system configuration of the drying processing unit 17 in the first embodiment.

[0103] In the entire system, a fluid supply source 51 is provided upstream of the drying unit 17, and the supercritical fluid 70 is supplied from the fluid supply source 51 to the drying unit 17 for making the supercritical fluid 70 (see Figure 7 ) flows through the supply passage. The fluid supply source 51 stores, for example, raw material CO 2 for the supercritical fluid 70 for generating CO 2 .

[0104] Furthermore, valves 63a and 63b are provided in order from upstream to downstream between the fluid supply source 51 and the drying unit 17. The terms upstream and downstream are used with reference to the flow direction of the supercritical fluid 70 in the supply path.

[0105] Valve 63a is a valve that adjusts the on / off state of the supply of supercritical fluid 70 from fluid supply source 51. When open, supercritical fluid 70 flows through the downstream supply passage, and when closed, supercritical fluid 70 does not flow through the downstream supply passage. The supply passage between fluid supply source 51 and drying unit 17 is an example of a second supply passage.

[0106] The valve 63b is a valve for adjusting the on / off of the supply of the supercritical fluid 70 to the drying process unit 17. The supply passage connected from the valve 63b to the drying process unit 17 is connected to the supply passage of the supercritical fluid 70. Figure 4 The supply port 35A is connected to the valve 63 b, and the supercritical fluid 70 flowing through the valve 63 b is supplied to the interior of the main body 31 via the supply port 35A and the fluid supply nozzle 37A.

[0107] A supply path branches off between the valve 63a and the valve 63b. Specifically, a supply path branches off from the supply path between the valve 63a and the valve 63b and extends to connect to the drying processing unit 17 via the valve 63c.

[0108] The supply passage connected to the drying process unit 17 via the valve 63c is an auxiliary flow passage for supplying the supercritical fluid 70 to the drying process unit 17. Figure 4 The supercritical fluid 70 that has passed through the valve 63 c is supplied to the interior of the main body 31 via the supply port 35B and the fluid supply nozzle 37B.

[0109] A supply source 52 and a supply source 53 are provided upstream of the drying treatment unit 17. The supply source 52 is a supply source of a liquid such as liquefied CO2 used as a supercritical fluid in the cleaning fluid diffusion treatment (S3), and the supply source 53 is a supply source of a solvent used in the cleaning fluid diffusion treatment (S3). The solvent contains polar molecules, and the boiling point of the solvent is lower than that of IPA. The solvent includes, for example, methanol, ethanol, acetone, or ethyl acetate. Between the supply source 52 and the supply source 53 and the drying treatment unit 17, a mixing section 54 is provided for mixing the liquid supplied from the supply source 52 and the solvent supplied from the supply source 53. A cleaning fluid generating section 55 is provided between the mixing section 54 and the drying treatment unit 17, which generates a cleaning fluid 80 using the mixed liquid generated by the mixing section 54. The cleaning fluid generating section 55 includes a pump 56 and a heater 57 arranged from the upstream side to the downstream side. The supply path for supplying the cleaning fluid 80 to the drying processing unit 17 is connected to the supply path for the supercritical fluid 70 via the valve 63 d at a position upstream of the branch point between the valves 63 a and 63 b .

[0110] Valve 63d is a valve that adjusts the on / off state of the supply of cleaning fluid 80 to drying processing unit 17. When open, cleaning fluid 80 flows through the downstream supply passage, and when closed, cleaning fluid 80 does not flow through the downstream supply passage. The supply passage between cleaning fluid generator 55 and drying processing unit 17 is an example of a first supply passage.

[0111] A valve 63e is provided downstream of the drying unit 17. The valve 63e is used to adjust the on / off state of the discharge of the supercritical fluid 70 or the cleaning fluid 80 from the drying unit 17. When the supercritical fluid 70 or the cleaning fluid 80 is discharged from the drying unit 17, the valve 63e is controlled to be in an open state. When the supercritical fluid 70 or the cleaning fluid 80 is not discharged from the drying unit 17, the valve 63e is controlled to be in a closed state.

[0112] In addition, a pressure sensor for detecting the pressure of the fluid and a temperature sensor for detecting the temperature of the fluid are provided in the supply passage. Figure 5 In the illustrated example, a pressure sensor 61 is provided between the drying unit 17 and the valve 63e, and a temperature sensor 62 is provided to detect the temperature of the fluid in the drying unit 17. Pressure sensors and temperature sensors may be provided at various locations in the supply path as needed.

[0113] Figure 6 1 is a block diagram showing the functional structure of the control device 4. As described above, the control device 4 includes the control unit 19 and the storage unit 20. The control device 4 is Figure 5 The various elements shown receive measurement signals and Figure 5 The various elements shown send control instruction signals.

[0114] The control device 4 receives measurement results from, for example, the pressure sensor 61 and the temperature sensor 62, and sends control instruction signals to valves 63a through 63e. The signals that the control device 4 can send and receive are not particularly limited. Valves 63a and 63d are examples of valves that can switch the fluid supplied to the substrate processing device between a cleaning fluid and a supercritical fluid. The diffusion unit includes the control device 4, the cleaning fluid generator 55, valves 63b through 63d, and a supply path between the cleaning fluid generator 55 and the drying process unit 17.

[0115] <Overview of Drying Process Using Supercritical Fluid>

[0116] Next, an overview of the drying process of the IPA liquid 71 using the supercritical fluid 70 will be described. Figure 7 This is a diagram for explaining the drying principle of the IPA liquid 71 and is an enlarged cross-sectional view that simply shows a pattern P on a wafer W.

[0117] When the supercritical fluid 70 of CO2 is just introduced into the main body 31 of the drying unit 17, as shown in FIG. Figure 7 As shown in (a), the space between the patterns P is filled with only IPA liquid 71.

[0118] The IPA liquid 71 between the above-mentioned patterns P gradually dissolves in the supercritical fluid 70 of CO2 by contacting with the supercritical fluid 70 of CO2, as shown in FIG. Figure 7 As shown in (b), it is gradually replaced by the supercritical fluid 70. At this time, between the patterns P, in addition to the IPA liquid 71 and the CO2 supercritical fluid 70, there is also a mixed fluid 70a in which the IPA liquid 71 and the CO2 supercritical fluid 70 are mixed.

[0119] Then, as the IPA liquid 71 is replaced by the CO2 supercritical fluid 70 between the patterns P, the IPA liquid 71 is removed from between the patterns P. Figure 7 As shown in (c), the space between the patterns P is filled with only a supercritical fluid 70 of CO 2 .

[0120] After the IPA liquid 71 is removed from between the patterns P, the pressure in the main body 31 is reduced to atmospheric pressure, as shown in FIG. Figure 7 As shown in (d), the supercritical fluid 70 of CO2 changes from a supercritical state to a gaseous state, and only the gas occupies the space between the patterns P. In this way, the IPA liquid 71 between the patterns P can be removed, and the drying process of the wafer W is completed.

[0121] Here, the supercritical fluid 70 has a lower viscosity than a liquid (e.g., IPA liquid 71) and a higher ability to dissolve liquids. Furthermore, no interface exists between the liquid or gas in equilibrium with the supercritical fluid 70. Therefore, in the drying process using the supercritical fluid 70, the liquid can be dried without being affected by surface tension, thereby suppressing pattern degradation of the pattern P.

[0122] On the other hand, during the drying process using the CO2 supercritical fluid 70 in the substrate processing system 100 described herein, IPA residue may adhere to the wafer W. The present inventors have conducted extensive research into the cause of IPA residue and discovered that IPA is a polar molecule while CO2 is a non-polar molecule. Therefore, IPA is insoluble in CO2, resulting in the generation of IPA residue. Furthermore, they discovered that by supplying a polar solvent with a lower boiling point than IPA to the drying process unit 17 along with the supercritical fluid to remove the IPA residue from within the drying process unit 17, the adhesion of IPA residue to the wafer W can be suppressed.

[0123] <Details of Cleaning Process of Substrate Processing System>

[0124] Here, details of the process of cleaning the drying processing unit 17 in the substrate processing system 100 according to the first embodiment will be described. Figure 8 This is a flowchart showing the cleaning process of the drying process unit 17 in the first embodiment. Figures 9A to 9C 1 is a diagram showing an overview of the cleaning process of the drying process unit 17 in the first embodiment. Figure 8 The cleaning process of the substrate processing system 100 shown is implemented as follows: the control unit 19 reads a program stored in the storage unit 20 of the control device 4, and controls the cleaning processing unit 16, the drying processing unit 17, etc. based on the read command.

[0125] In the first embodiment, first, in the mixing unit 54 , a liquid such as liquid CO 2 supplied from the supply source 52 and a solvent such as methanol, ethanol, or acetone supplied from the supply source 53 are mixed to generate a mixed liquid (step S11 ).

[0126] Next, the cleaning fluid generator 55 converts the liquid in the mixed liquid supplied from the supply source 52 into a supercritical fluid, thereby generating a cleaning fluid 80 formed by mixing the solvent and the supercritical fluid (step S12). The solvent contained in the cleaning fluid 80 generated by the cleaning fluid generator 55 may be maintained in a liquid state or may be vaporized in the cleaning fluid generator 55.

[0127] After that, the cleaning fluid 80 is diffused in the interior of the drying processing unit 17 (step S13). Specifically, the control unit 19 of the control device 4 is as follows. Figure 9A As shown, valves 63a and 63e are controlled to be in a closed state, while valves 63b to 63d are controlled to be in an open state. In addition, the temperature inside the drying processing unit 17 is set to a temperature above the boiling point of the solvent. Through the above-mentioned control, the cleaning fluid 80 is supplied from the cleaning fluid generating section 55 to the interior of the drying processing unit 17 via valves 63b to 63d, and the cleaning fluid 80 diffuses inside the drying processing unit 17. At this time, the solvent contained in the cleaning fluid 80 becomes a gas. When the cleaning fluid 80 diffuses inside the drying processing unit 17, the IPA residue dissolves in the solvent contained in the cleaning fluid 80. Then, the cleaning fluid 80 is allowed to diffuse inside the drying processing unit 17, and the system waits for a predetermined time. The waiting time is, for example, more than 30 minutes.

[0128] Then, the supercritical fluid 70 is diffused in the drying unit 17 (step S14). Specifically, the control unit 19 of the control device 4 is as follows. Figure 9B As shown, valves 63d and 63e are controlled to be closed, while valves 63a to 63c are controlled to be open. Through the above-described control, supercritical fluid 70 is supplied from fluid supply source 51 through valves 63a to 63c into the interior of drying processing unit 17, and supercritical fluid 70 diffuses within drying processing unit 17. As a result, the interior of drying processing unit 17 is filled with supercritical fluid 70 and cleaning fluid 80. While the interior of drying processing unit 17 is filled with supercritical fluid 70 and cleaning fluid 80, control unit 19 controls the interior of drying processing unit 17 to maintain a temperature at which supercritical fluid 70 can maintain a supercritical state. That is, in step S14, similar to the drying process for wafer W, control unit 19 controls the drying process within drying processing unit 17 using supercritical fluid 70.

[0129] Next, the supercritical fluid 70 and the cleaning fluid 80 are discharged from the interior of the drying unit 17 (step S15). Specifically, the control unit 19 of the control device 4 is as follows: Figure 9C As shown, valves 63a to 63d are controlled to be closed, while valve 63e is controlled to be open. Through the above control, supercritical fluid 70 and cleaning fluid 80 are discharged from drying unit 17 via valve 63e. IPA residue dissolves in the solvent contained in cleaning fluid 80, so it can be removed along with cleaning fluid 80. When the discharge of cleaning fluid 80 is complete, the cleaning process of drying unit 17 is complete. Furthermore, the drying process using supercritical fluid 70 was performed in step S14, and the drying process inside drying unit 17 is also complete.

[0130] As described above, according to the first embodiment, IPA residue inside the drying processing unit 17 can be easily removed. Therefore, it is possible to suppress the adhesion of particles to the wafer W. In addition, since the boiling point of the solvent is lower than that of IPA, the solvent containing IPA can be easily discharged from the drying processing unit 17.

[0131] In the first embodiment, not only the interior of the drying process unit 17 but also the interior of the supply passage between the cleaning fluid generator 55 and the drying process unit 17 and the interior of the supply passage downstream of the drying process unit 17 can be cleaned using the cleaning fluid 80 .

[0132] Can be performed repeatedly in one cleaning process Figure 8 By repeatedly performing the above-mentioned processing steps in one cleaning process, the IPA residue in the drying process unit 17 can be further removed.

[0133] The configurations of the mixing unit 54 and the cleaning fluid generating unit 55 are merely examples, and the configuration of the portion that supplies the cleaning fluid to the drying processing unit 17 is not limited to that of the first embodiment.

[0134] Regarding the cleaning process of the substrate processing system 100, for example, in each drying processing unit 17, the number of particles on the wafer W subjected to the drying process is measured in real time by a particle counter, and the cleaning process is performed when the measured number of particles reaches a predetermined number or more.

[0135] In addition, regarding the cleaning process of the substrate processing system 100, for example, in each drying processing unit 17, it can be performed when the cumulative time of the drying process of the chip W becomes longer than the specified time, or when the cumulative number of the drying process chips W becomes longer than the specified number.

[0136] (Second embodiment)

[0137] The second embodiment is described below. The second embodiment differs from the first embodiment mainly in the structure for diffusing the cleaning fluid 80 inside the drying process unit 17 . Figure 10 It is a diagram showing a schematic configuration of a substrate processing system 200 according to the second embodiment. Figure 11 1 is a diagram showing an example of the overall system configuration of the drying processing unit 17 in the second embodiment.

[0138] like Figure 10As shown, in the substrate processing system 200 of the second embodiment, the conveyor unit 12 includes a jig placement unit 21. A jig 22 is placed on the jig placement unit 21. The wafer holding mechanism in the substrate conveyor 13 also holds the jig 22. Furthermore, the substrate conveyor 13 uses the wafer holding mechanism to transport the jig 22 between the jig placement unit 21 and the interface 14.

[0139] In the second embodiment, the wafer holding mechanism of the substrate transport device 18 can hold not only the wafer W but also the jig 22. The substrate transport device 18 transports the wafer W or the jig 22 between the interface 14, the cleaning unit 16, and the drying unit 17 using the wafer holding mechanism.

[0140] In addition, Figure 3 In the cleaning processing unit 16 shown in FIG. 1 , a solvent 81 (see Figure 13A ) is supplied to the mechanism of the jig 22.

[0141] like Figure 11 As shown, the supply source 52, the supply source 53, the mixing unit 54, the cleaning fluid generating unit 55 and the valve 63d may not be provided.

[0142] The other structures are the same as those of the first embodiment.

[0143] Here, details of the process of cleaning the drying processing unit 17 in the substrate processing system 200 according to the second embodiment will be described. Figure 12 This is a flowchart showing the cleaning process of the drying process unit 17 in the second embodiment. Figures 13A to 13C This is a diagram showing an overview of a cleaning process of a drying process unit in the second embodiment.

[0144] In the second embodiment, first, the substrate transport device 18 (see Figure 10 ) The jig 22 is sent to the cleaning processing unit 16. The jig 22 is held by the wafer holding mechanism 25 (see FIG. 2 ) with the wheel-shaped portion 22b facing upward. Figure 3 Then, the control unit 19 controls the cleaning processing unit 16 to supply the solvent 81 to the jig 22 (step S21).

[0145] In supplying the solvent 81, first, Figure 10 The substrate transport device 13 of the loading and unloading station 2 shown removes the jig 22 placed on the jig placement portion 21 and places the removed jig 22 on the delivery portion 14. The jig 22 placed on the delivery portion 14 is removed from the delivery portion 14 by the substrate transport device 18 of the processing station 3 and transported to the cleaning processing unit 16.

[0146] The cleaning unit 16 supplies the solvent 81 to the jig 22 sent to the cleaning unit 16. Specifically, the cleaning unit 16 moves the nozzle arm 26 into the position held in the cleaning unit 16. Figure 3 A solvent 81 is supplied from a solvent nozzle (not shown) provided at the front end of a nozzle arm 26 above the jig 22 of the wafer holding mechanism 25 shown in the figure, thereby supplying the solvent to the jig 22 .

[0147] Next, the substrate transport device 18 sends the jig 22 supplied with the solvent 81 out of the cleaning processing unit 16. Figure 13A As shown, it is sent into the drying processing unit 17 (step S22). In the process of sending the jig 22, first, the supplied jig 22 is held on the holding plate 32 (refer to Figure 4 Then, the holding plate 32 and the cover member 33 are stored together with the supplied jig 22 in the interior of the main body 31, and the opening 34 is sealed with the cover member 33. Figure 13A As shown, when the jig 22 is fed in, the valves 63a to 63c and 63e are all controlled to be closed.

[0148] Next, the supercritical fluid 70 and the cleaning fluid 80 are diffused in the interior of the drying processing unit 17 (step S23). Specifically, the control unit 19 of the control device 4 is as follows: Figure 13B As shown, valve 63e is controlled to be closed, while valves 63a to 63c are controlled to be open. Furthermore, the temperature inside the drying processing unit 17 is set to a temperature above the boiling point of the solvent. Through the above control, supercritical fluid 70 is supplied from the fluid supply source 51 through valves 63a to 63c into the drying processing unit 17. Solvent 81 supplied to the jig 22 is vaporized, and cleaning fluid 80, a mixture of supercritical fluid 70 and vaporized solvent 81, diffuses into the drying processing unit 17. As cleaning fluid 80 diffuses into the drying processing unit 17, IPA residue dissolves in the solvent contained in cleaning fluid 80. Then, the system waits for a predetermined time while cleaning fluid 80 diffuses into the drying processing unit 17. The interior of the drying processing unit 17 is filled with supercritical fluid 70 and cleaning fluid 80. While the interior of the drying processing unit 17 is filled with the supercritical fluid 70 and the cleaning fluid 80, the control unit 19 controls the interior of the drying processing unit 17 to maintain a temperature at which the supercritical fluid 70 can maintain a supercritical state. That is, in step S23, the control unit 19 controls the drying process inside the drying processing unit 17 using the supercritical fluid 70, similarly to the drying process of the wafer W.

[0149] Next, the supercritical fluid 70 and the cleaning fluid 80 are discharged from the interior of the drying unit 17 (step S24). Specifically, the control unit 19 of the control device 4 is as follows: Figure 13CAs shown, valves 63a to 63c are controlled to be closed, while valve 63e is controlled to be open. Through this control, supercritical fluid 70 and cleaning fluid 80 are discharged from drying unit 17 via valve 63e. Therefore, IPA residue within drying unit 17 can be removed together with cleaning fluid 80.

[0150] Then, the jig 22 is removed from the drying unit 17 (step S25). When the removal of the jig 22 is complete, the cleaning process of the drying unit 17 is complete. Furthermore, the drying process using the critical fluid 70 in step S23 completes the drying process inside the drying unit 17.

[0151] According to the second embodiment, the drying process unit 17 does not require additional piping, valves, etc., and can be realized by simply providing the jig placement unit 21 and the jig 22 within the substrate processing system 200. Therefore, according to the second embodiment, the cleaning process of the drying process unit 17 can be performed at a low cost.

[0152] Can be performed repeatedly in one cleaning process Figure 12 By repeatedly performing the above-mentioned processing steps in one cleaning process, the IPA residue in the drying process unit 17 can be further removed.

[0153] Here, use Figure 14A and Figure 14B An example of the jig 22 will be described. Figure 14A 2 is a perspective view showing an example of the jig 22. Figure 14B It is a cross-sectional view showing an example of the jig 22 . Figure 14B Equivalent to along Figure 14A Cross-sectional view of line AA.

[0154] like Figure 14A and Figure 14B As shown, the jig 22 includes a circular plate portion 22a and a wheel-shaped portion 22b.

[0155] The circular plate portion 22 a has substantially the same diameter and thickness as the wafer W. Thus, in the substrate processing system 200 , the jig 22 can be transported using the substrate transport device 13 , the interface 14 , and the substrate transport device 18 for transporting the wafer W, and the jig 22 can be sent to the cleaning processing unit 16 and the drying processing unit 17 for processing the wafer W.

[0156] Furthermore, when the substrate processing system 200 can process wafers W having various diameters and thicknesses, the circular plate portion 22 a only needs to have substantially the same diameter and thickness as one wafer W among the various wafers that the substrate processing system 200 can process.

[0157] The wheel-shaped portion 22b is a portion protruding in a wheel shape from the main surface of the front side of the circular plate portion 22a. Furthermore, the circular plate portion 22a and the wheel-shaped portion 22b form a recessed portion 22c on the main surface of the front side of the circular plate portion 22a. By forming the recessed portion 22c on the main surface of the front side of the circular plate portion 22a, the amount of solvent 81 that can be supplied to the surface of the jig 22 can be increased compared to a case where the recessed portion 22c is not formed.

[0158] The wheel-shaped portion 22b is provided at a predetermined distance or more from the edge 22d of the circular plate portion 22a. Thus, in the substrate processing system 200, when the jig 22 is transported using the substrate transport device 13, the interface 14, and the substrate transport device 18, the jig 22 can be transported by gripping the edge 22d of the circular plate portion 22a.

[0159] (Third embodiment)

[0160] Next, the third embodiment will be described. The third embodiment has a structure in which the second embodiment is combined with the first embodiment. Figure 10 As shown, the jig placement unit 21 is provided in the transport unit 12 , and the jig 22 is placed on the jig placement unit 21 . Furthermore, a mechanism for supplying the solvent 81 to the jig 22 is added to the cleaning processing unit 16 .

[0161] The other structures are the same as those of the first embodiment. That is, unlike the second embodiment, a supply source 52, a supply source 53, a mixing unit 54, a cleaning fluid generating unit 55 and a valve 63d are provided (see Figure 5 ).

[0162] Here, details of the process of cleaning the drying processing unit 17 in the substrate processing system according to the third embodiment will be described. Figure 15 This is a flowchart showing the cleaning process of the drying process unit 17 in the third embodiment. Figures 16A to 16D This is a diagram showing an overview of a cleaning process of a drying process unit in the third embodiment.

[0163] First, similarly to the first embodiment, the liquid supplied from the supply source 52 and the solvent supplied from the supply source 53 are mixed in the mixing unit 54 to produce a mixed liquid (step S31). Next, the cleaning fluid generating unit 55 generates the cleaning fluid 80 (step S32).

[0164] Then, similarly to the second embodiment, the control unit 19 controls the cleaning processing unit 16 to supply the solvent 81 to the jig 22 (step S33). Next, the substrate transport device 18 sends the jig 22 supplied with the solvent 81 out of the cleaning processing unit 16. Figure 16A As shown, it is sent to the drying processing unit 17 (step S34). Figure 16AAs shown, when the jig 22 is fed in, all valves 63a to 63e are controlled to be closed.

[0165] Then, the cleaning fluid 80 is diffused in the interior of the drying processing unit 17 (step S35). Specifically, the control unit 19 of the control device 4 is as follows. Figure 16B As shown, valves 63a and 63e are controlled to be closed, while valves 63b to 63d are controlled to be open. Furthermore, the temperature inside drying processing unit 17 is set to a temperature above the boiling point of the solvent. Through the above control, cleaning fluid 80 is supplied from cleaning fluid generator 55 into drying processing unit 17 via valves 63b to 63d. Solvent 81 supplied to jig 22 vaporizes, and cleaning fluid 80 containing vaporized solvent 81 diffuses within drying processing unit 17. As cleaning fluid 80 diffuses within drying processing unit 17, IPA residue dissolves in the solvent contained in cleaning fluid 80. The system then waits for a predetermined period of time while cleaning fluid 80 diffuses within drying processing unit 17.

[0166] Then, the supercritical fluid 70 is diffused in the drying unit 17 (step S36). Specifically, the control unit 19 of the control device 4 is as follows. Figure 16C As shown, valves 63d and 63e are controlled to be closed, while valves 63a to 63c are controlled to be open. Through the above control, supercritical fluid 70 is supplied from fluid supply source 51 through valves 63a to 63c into the interior of drying processing unit 17, and supercritical fluid 70 diffuses within drying processing unit 17. As a result, the interior of drying processing unit 17 is filled with supercritical fluid 70 and cleaning fluid 80. While the interior of drying processing unit 17 is filled with supercritical fluid 70 and cleaning fluid 80, control unit 19 controls the interior of drying processing unit 17 to maintain a temperature at which supercritical fluid 70 can maintain a supercritical state. That is, in step S36, similar to the drying process for wafer W, control unit 19 controls the drying process inside drying processing unit 17 using supercritical fluid 70.

[0167] Next, the supercritical fluid 70 and the cleaning fluid 80 are discharged from the interior of the drying unit 17 (step S37). Specifically, the control unit 19 of the control device 4 is as follows: Figure 16D As shown, valves 63a to 63d are controlled to be closed, while valve 63e is controlled to be open. Through this control, supercritical fluid 70 and cleaning fluid 80 are discharged from drying unit 17 via valve 63e. Therefore, IPA residue within drying unit 17 can be removed together with cleaning fluid 80.

[0168] Afterwards, the jig 22 is removed from the drying unit 17 (step S38). When the removal of the jig 22 is complete, the cleaning process of the drying unit 17 is complete. Furthermore, the drying process using the supercritical fluid 70 in step S36 also completes the drying process inside the drying unit 17.

[0169] According to the third embodiment, a better cleaning effect can be obtained, that is, the IPA residue can be removed more reliably.

[0170] Can be performed repeatedly in one cleaning process Figure 15 By repeatedly performing this processing step in one cleaning process, the IPA residue in the drying process unit 17 can be further removed.

[0171] (Fourth embodiment)

[0172] Next, the fourth embodiment will be described. According to the research of the inventors of the present application, in the drying process (S1), there are situations where pollutants containing metals (hereinafter sometimes referred to as "pollutants") are attached to the wafer as particles, and where the pollutants do not react with the supercritical fluid. The metal is, for example, a transition metal. It is also known that by supplying a chelating agent that reacts with the metal to the drying process unit 17 together with the supercritical fluid to remove the pollutants from the inside of the drying process unit 17, it is possible to suppress the pollutants from adhering to the wafer. The fourth embodiment is different from the first embodiment mainly in that the cleaning fluid contains a chelating agent instead of a solvent. Figure 17 It is a diagram showing an example of the overall system configuration of the drying processing unit 17 in the fourth embodiment.

[0173] like Figure 17 As shown, in the fourth embodiment, a supply source 153 of a solution containing a chelating agent is provided instead of the supply source 53 of the solvent. A mixing section 154 is provided between the supply sources 52 and 153 and the drying processing unit 17 to mix the liquid supplied from the supply source 52 with the solution supplied from the supply source 153. A cleaning fluid generating section 155 is provided between the mixing section 154 and the drying processing unit 17 to generate a cleaning fluid 180 (see FIG. 1 ) from the mixed liquid generated by the mixing section 154. Figure 18 The cleaning fluid generator 155 includes a pump 56 and a heater 57 arranged from upstream to downstream. The supply path for the cleaning fluid 180 to the drying unit 17 is connected to the supply path for the supercritical fluid 70 via a valve 63f at a point upstream of the branch point between valves 63a and 63b.

[0174] The valve 63f is a valve for adjusting the on / off supply of the cleaning fluid 180 to the drying processing unit 17. When it is open, the cleaning fluid 180 flows through the supply passage on the downstream side. When it is closed, the cleaning fluid 180 does not flow through the supply passage on the downstream side.

[0175] Chemical formula 1 shows an example of the chelating agent supplied from the supply source 153. The chelating agent is preferably an atomic group having affinity with CO2 used in the supercritical fluid. Examples of atomic groups having affinity with CO2 include perfluoropolyether (PFPE), polydimethylsiloxane, and perfluorooctanoyl.

[0176]

[0177] The other structures are the same as those of the first embodiment.

[0178] Here, details of the process of cleaning the drying processing unit 17 in the substrate processing system of the fourth embodiment will be described. In this cleaning process, as shown below, the cleaning process is performed in the same steps as the first embodiment. Figure 18 It is a diagram showing an outline of a cleaning process of a drying processing unit in the fourth embodiment.

[0179] In the fourth embodiment, first, in the mixing unit 154 , a liquid supplied from the supply source 52 , for example, liquid CO 2 , and a solution containing a chelating agent supplied from the supply source 153 are mixed to generate a mixed liquid.

[0180] Next, in the cleaning fluid generating unit 155 , the liquid supplied from the supply source 52 in the mixed liquid is converted into a supercritical fluid, thereby generating a cleaning fluid 180 in which the solution containing the chelating agent and the supercritical fluid are mixed.

[0181] Then, the cleaning fluid 180 is diffused in the interior of the drying processing unit 17. Specifically, the control unit 19 of the control device 4 is as follows. Figure 18 As shown, valves 63a and 63e are controlled to be closed, while valves 63b, 63c, and 63f are controlled to be open. Through the above control, cleaning fluid 180 is supplied from cleaning fluid generating section 55 to the interior of drying processing unit 17 via valves 63b, 63c, and 63f, and cleaning fluid 180 diffuses within drying processing unit 17. When cleaning fluid 180 diffuses within drying processing unit 17, as shown in Chemical Formula 2, metal ions (M+) in the contaminants form a complex with the chelating agent contained in cleaning fluid 180. Then, while cleaning fluid 180 diffuses within drying processing unit 17, the system waits for a predetermined time. The waiting time is, for example, more than 30 minutes.

[0182]

[0183] Next, cleaning fluid 180 is discharged from the interior of drying unit 17. Specifically, as in the first embodiment, control unit 19 of control device 4 controls valves 63a to 63c and 63f to be closed, and valve 63e to be open. Through the above control, cleaning fluid 180 is discharged from drying unit 17 via valve 63e. The metals in the contaminants form complexes with the chelating agent contained in cleaning fluid 180, thereby removing the contaminants along with cleaning fluid 180. When the discharge of cleaning fluid 180 is complete, the cleaning process of drying unit 17 is complete.

[0184] As described above, according to the fourth embodiment, contaminants inside the drying processing unit 17 can be easily removed. Therefore, it is possible to suppress particles from adhering to the wafer W. Furthermore, when the chelating agent has an atomic group with a strong affinity for CO 2 , the chelating agent can be particularly easily discharged from the drying processing unit 17 .

[0185] As in the first embodiment, the above-mentioned processing steps can be repeatedly performed in one cleaning process. By repeatedly performing the above-mentioned processing steps in one cleaning process, the IPA residue in the drying process unit 17 can be further removed.

[0186] Alternatively, as in the second embodiment, the jig 22 supplied with the solution containing the chelating agent may be introduced into the drying unit 17 , and the solution may be vaporized to diffuse the cleaning fluid 180 containing the vaporized chelating agent into the drying unit 17 .

[0187] Alternatively, as in the third embodiment, a cleaning fluid 180 formed by mixing a solution containing a chelating agent and a supercritical fluid may be supplied from the cleaning fluid generating portion 55 to the drying processing unit 17 , and the solution containing the chelating agent supplied to the jig 22 may be vaporized, thereby causing the cleaning fluid 180 containing the vaporized chelating agent to diffuse within the drying processing unit 17 .

[0188] (Fifth embodiment)

[0189] Next, a fifth embodiment will be described. The fifth embodiment differs from the first embodiment mainly in that a cleaning fluid containing a chelating agent is used in addition to a cleaning fluid containing a solvent. Figure 19 1 is a diagram showing an example of the overall system configuration of the drying processing unit 17 in the fifth embodiment.

[0190] In the fifth embodiment, in addition to the supply source 52, the supply source 53, the mixing section 54, the cleaning fluid generating section 55 and the valve 63d, a supply source 153, a mixing section 154, a cleaning fluid generating section 155 and a valve 63f are also provided on the upstream side of the drying processing unit 17, similar to the fourth embodiment.

[0191] The other structures are the same as those of the first embodiment.

[0192] In the process of cleaning the drying processing unit 17 in the substrate processing system of the fifth embodiment, for example, the IPA residue is removed using the cleaning fluid 80 as in the first embodiment, and then the metal-containing contaminants are removed using the cleaning fluid 180 as in the fourth embodiment.

[0193] According to the fifth embodiment, both IPA residue and metal-containing contaminants can be easily removed from the interior of the drying processing unit 17. Therefore, adhesion of particles to the wafer W can be further suppressed.

[0194] Alternatively, the metal-containing contaminants may be removed using the cleaning fluid 180 as in the fourth embodiment, and then the IPA residue may be removed using the cleaning fluid 80 as in the first embodiment. Furthermore, the IPA residue and the contaminants may be removed simultaneously, while the solvent 81 and the solution containing the chelating agent do not react with each other and independently dissolve the IPA residue and form a complex with the metal ions contained in the contaminants.

[0195] Preferred embodiments have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope described in the claims.

Claims

1. A method for cleaning a substrate processing apparatus, wherein the substrate processing apparatus is capable of performing a drying process, wherein a substrate whose surface is wetted by a liquid is brought into contact with a supercritical fluid to dry the substrate. The cleaning method of the substrate processing device is characterized by comprising: a step of diffusing a cleaning fluid within the substrate processing apparatus, wherein the cleaning fluid is obtained by mixing the supercritical fluid with a solvent containing polar molecules and having a lower boiling point than the liquid; as well as the step of discharging the cleaning fluid from the interior of the substrate processing apparatus after the cleaning fluid has diffused; The liquid contains polar molecules, and the supercritical fluid contains non-polar molecules.

2. The cleaning method of a substrate processing device according to claim 1, wherein: The step of diffusing the cleaning fluid includes the step of supplying the cleaning fluid into the interior of the substrate processing apparatus.

3. The method for cleaning a substrate processing device according to claim 1 or 2, wherein: The step of diffusing the cleaning fluid comprises: a step of introducing the jig supplied with the solvent into the interior of the substrate processing apparatus; and After the jig is introduced, the solvent is vaporized inside the substrate processing apparatus while the supercritical fluid is supplied to the inside of the substrate processing apparatus.

4. The method for cleaning a substrate processing device according to claim 1 or 2, wherein: The liquid comprises isopropyl alcohol, The solvent comprises ethanol, methanol or acetone or any combination thereof.

5. The cleaning method of a substrate processing device according to claim 1 or 2, wherein: Also includes: a step of diffusing a second cleaning fluid inside the substrate processing apparatus, wherein the second cleaning fluid is obtained by mixing the supercritical fluid with a solution containing a chelating agent; as well as and discharging the second cleaning fluid from the interior of the substrate processing apparatus after the second cleaning fluid has diffused.

6. The method for cleaning a substrate processing device according to claim 1 or 2, wherein: comprising the step of diffusing the supercritical fluid inside the substrate processing apparatus between the step of diffusing the cleaning fluid and the step of discharging the cleaning fluid, In the step of discharging the cleaning fluid, the supercritical fluid is also discharged from the interior of the substrate processing apparatus.

7. A substrate processing system, characterized in that: include: a substrate processing device capable of performing a drying process in which a substrate whose surface is wetted by a liquid is brought into contact with a supercritical fluid to dry the substrate; a diffusion unit for diffusing a cleaning fluid within the substrate processing apparatus, wherein the cleaning fluid is a mixture of the supercritical fluid and a solvent containing polar molecules and having a lower boiling point than the liquid; as well as a discharge portion for discharging the cleaning fluid from the interior of the substrate processing apparatus; The liquid contains polar molecules, and the supercritical fluid contains non-polar molecules.

8. The substrate processing system according to claim 7, wherein: include: supplying the cleaning fluid to a first supply passage of the substrate processing device; supplying the supercritical fluid to a second supply path of the substrate processing apparatus independently of the cleaning fluid; as well as A valve connecting the first supply path and the second supply path switches the fluid to be supplied to the substrate processing apparatus between the cleaning fluid and the supercritical fluid.

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