Substrate processing method and substrate processing system

Abstract

The invention provides a substrate processing method capable of reducing the consumption of a processing fluid, reducing the environmental burden and improving the yield. A substrate processing method and a substrate processing system according to the present invention perform a preliminary organic solvent supply process between a chemical solution process and a rinsing process. Subsequently, after the rinsing treatment, replacement treatment using an organic solvent and liquid deposition treatment (liquid film formation treatment) are performed, and a liquid film is formed. At this time, the rinsing liquid is sometimes left in the pattern, but the remaining position of the rinsing liquid is not the inner bottom surface of the pattern, and is sandwiched in the vertical direction by a liquid layer (= IPA + DIW) containing two organic solvents. The rinsing liquid constituting the residual liquid diffuses between the liquid layers to form a non-residual liquid. In this state, a drying process is performed on the basis of the treatment fluid in the supercritical state.

Description

Technical Field

[0001] The present invention relates to a technology for drying a substrate in a processing chamber, and more particularly to a process for processing a substrate covered by a liquid film using a processing fluid in a supercritical state.

[0002] The disclosures of the following Japanese patent applications, including the specification, drawings, and claims, are incorporated herein by reference in their entirety:

[0003] JP Special Application No. 2023-138194 (applied on August 28, 2023). Background Art

[0004] The processing steps of various substrates such as semiconductor substrates and glass substrates for display devices include the steps of treating the surface of the substrate using various processing fluids. In the past, wet processing using liquids such as chemical solutions or rinse solutions as processing fluids has been widely carried out. In recent years, in order to dry the substrate after the wet processing, the processing using a processing fluid in a supercritical state has also been put into practical use. It is particularly beneficial in the drying process of a substrate having a pattern forming surface with a fine pattern formed thereon. This is because the processing fluid in a supercritical state has the characteristics of low surface tension compared to a liquid and can penetrate deep into the gaps of the pattern. By using this processing fluid, the drying process can be carried out efficiently. In addition, the risk of pattern collapse caused by surface tension during drying can also be reduced.

[0005] For example, in the substrate processing system described in JP Patent Publication No. 2013-201302, a substrate developing device is provided as an example of the "wet processing device" of the present invention. In the substrate developing device, as the final treatment in the device, IPA (isopropyl alcohol) liquid, which is an example of the "organic solvent" of the present invention, is supplied to the substrate wetted with the rinse liquid. Thus, IPA replacement is performed to remove the rinse liquid from the surface of the substrate. In addition, a liquid pile state in which the IPA liquid is piled up is formed on the surface of the substrate. That is, the liquid film containing the IPA liquid is formed into a paddle shape. As a result, the surface of the substrate is maintained in a state wetted by the IPA liquid. Then, the substrate is transported by the substrate transport device to a substrate drying device, which is an example of the "supercritical processing device" of the present invention, while maintaining the liquid pile state, and a drying process based on the processing fluid in the supercritical state is performed on the substrate. Summary of the invention

[0006] In a wet processing device such as a substrate developing device or a substrate cleaning device, it is expected that the liquid such as a rinse liquid is completely discharged from the inside of the pattern by using IPA displacement. However, sometimes liquid remains on the inner bottom surface of the pattern. If the substrate is moved into a substrate drying device (supercritical processing device) and subjected to supercritical drying treatment in a state where such residual liquid (hereinafter referred to as "residual liquid") remains, the following problems may sometimes occur. In other words, the replacement of the liquid component constituting the liquid film with the processing fluid in a supercritical state is prone to incomplete. Therefore, in order to cope with this problem, a countermeasure of increasing the amount of processing fluid used is considered. However, this will lead to an increase in operating costs and will cause a great environmental burden on society.

[0007] In addition, even if the amount of processing fluid used is increased, residual liquid may remain directly on the inner bottom surface of the pattern, which may cause the pattern to collapse. Therefore, the presence of residual liquid is one of the main reasons for the reduction of product yield.

[0008] The present invention is proposed in view of the above-mentioned problems, and its purpose is to provide the following technology, namely, in a substrate processing system in which a substrate with an organic solvent deposited on the surface of the substrate that has been wet-treated is transferred from a wet processing device to a supercritical processing device, and the substrate is dried using a processing fluid in a supercritical state, the production capacity can be increased while reducing the consumption of the processing fluid and reducing the environmental burden.

[0009] One aspect of the present invention is a substrate processing method for processing a substrate, wherein the substrate has a pattern forming surface on which a pattern is formed, the substrate processing method comprising: (a) a process of sequentially performing a process of supplying a chemical solution to the pattern forming surface to treat the substrate with a chemical solution, supplying a preliminary organic solvent supply process to the pattern forming surface, supplying a rinse solution to the pattern forming surface, supplying a replacement process to the pattern forming surface, and a process of stacking the organic solvent on the pattern forming surface in a wet processing device; (b) a process of transporting the substrate from the wet processing device to a supercritical processing device while maintaining a stack state in which the organic solvent is stacked on the pattern forming surface due to the stacking process; and (c) a process of drying the substrate in the supercritical processing device by bringing the pattern forming surface in a stack state into contact with a processing fluid in a supercritical state.

[0010] In addition, another aspect of the present invention is a substrate processing system for processing a substrate, wherein the substrate has a pattern forming surface on which a pattern is formed, and the substrate processing system comprises: a wet processing device, which sequentially performs liquid treatment of the substrate by supplying a liquid to the pattern forming surface, a preliminary organic solvent supplying process of supplying an organic solvent to the pattern forming surface, a rinsing process of supplying a rinsing liquid to the pattern forming surface, a replacement process of supplying an organic solvent to the pattern forming surface, and a liquid heap treatment of forming a liquid heap state in which the organic solvent is piled on the pattern forming surface; a supercritical processing device, which dries the substrate by bringing the pattern forming surface in the liquid heap state into contact with a processing fluid in a supercritical state; and a substrate conveying device, which conveys the substrate from the wet processing device to the supercritical processing device while maintaining the liquid heap state.

[0011] Conventionally, in a wet processing device, after performing a liquid treatment by supplying a liquid to a pattern forming surface, a rinse treatment, a replacement treatment, and a liquid stack treatment are sequentially performed. Therefore, rinse liquid may remain on the inner bottom surface of the pattern. This residual liquid may cause an increase in the consumption of the processing fluid or a decrease in the yield of the product. Therefore, in the present invention, a preliminary organic solvent supply treatment is performed between the liquid treatment and the rinse treatment. Therefore, even if rinse liquid remains in the pattern, the residual position of the rinse liquid is not on the inner bottom surface of the pattern, but as described later, Figure 7 As shown in (b), it becomes a position sandwiched by two liquid layers in the vertical direction. The liquid layer on the vertically lower side of the two liquid layers is a layer of organic solvent used in the preliminary organic solvent supply process or a mixed layer of the organic solvent and the rinse liquid. The other liquid layer is a layer of organic solvent used in the replacement process or a mixed layer of the organic solvent and the rinse liquid. Therefore, until the substrate in the liquid pile state is transported to the supercritical processing device and contacts the supercritical state processing fluid, the rinse liquid constituting the residual liquid diffuses between the two adjacent liquid layers in the vertical direction and mixes with the organic solvent. As a result, the drying process based on the supercritical state processing fluid is performed using a state in which there is no residual liquid on the inner bottom surface of the pattern, that is, a so-called residual liquid-free state.

[0012] Effects of the Invention

[0013] As described above, according to the present invention, supercritical drying can be performed using a residual-free liquid, thereby reducing the consumption of the processing fluid and improving the yield.

[0014] The multiple components of the various aspects of the present invention described above are not all necessary. In order to solve part or all of the above-mentioned problems, or to achieve part or all of the effects described in this specification, some of the multiple components can be appropriately changed, deleted, replaced with new other components, or a part of the limited content can be deleted. In addition, in order to solve part or all of the above-mentioned problems, or to achieve part or all of the effects described in this specification, part or all of the technical features included in one aspect of the present invention described above can also be combined with part or all of the technical features included in other aspects of the present invention described above as an independent mode of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a diagram showing a schematic configuration of a first embodiment of a substrate processing system according to the present invention.

[0016] Figure 2A It is a side view showing the overall structure of the wet processing device.

[0017] Figure 2B It is a diagram for explaining the operation of the wet processing device.

[0018] Figure 3 It is a diagram schematically showing the structure and operation of the chuck pin.

[0019] Figure 4 It is a side view showing the structure of a supercritical processing apparatus.

[0020] Figure 5 It is a perspective view showing the structure of the support tray.

[0021] Figure 6 This is a flowchart showing an overview of processing executed by the substrate processing system according to the first embodiment.

[0022] Figure 7 This is a diagram schematically showing the difference in liquid film structure caused by the presence or absence of the preliminary organic solvent supply process.

[0023] Figure 8 is a diagram showing pressure changes in a processing chamber.

[0024] Fig. 9 This is a flowchart showing the operation of the second embodiment of the substrate processing system of the present invention.

[0025] The reference numerals are described as follows:

[0026] 1 Substrate processing system

[0027] 2 Wet treatment equipment

[0028] 3 Substrate transfer device

[0029] 4 Supercritical treatment device

[0030] 9 Control device

[0031] 95 Wet Processing Control Department

[0032] 96 Transport Control Department

[0033] 97 Supercritical Processing Control Department

[0034] AX Rotation axis

[0035] LF Liquid Film

[0036] LL2, LL4 liquid layer (=IPA+DIW)

[0037] LL3 liquid film (=DIW)

[0038] PT pattern

[0039] S substrate

[0040] Sa surface (patterning surface)

[0041] Z vertical direction DETAILED DESCRIPTION

[0042] Figure 1 1 is a diagram showing a schematic structure of a first embodiment of a substrate processing system of the present invention. The substrate processing system 1 is a processing system for supplying a processing liquid to the surface of various substrates such as semiconductor wafers to perform wet processing on the substrates and then drying the substrates, and has a system structure that is preferred for implementing the substrate processing method of the present invention. The substrate processing system 1 mainly includes a wet processing device 2, a substrate transport device 3, a supercritical processing device 4, and a control device 9.

[0043] The wet processing device 2 receives the substrate to be processed and performs a prescribed wet processing. The content of the processing is not particularly limited. The wet processing includes a development process using a chemical solution or a cleaning process of a clean substrate, etc., performed by the above-mentioned existing device, and a liquid pile state of an organic solvent such as IPA liquid is formed on the pattern forming surface of the substrate. The substrate conveying device 3 moves the substrate out of the wet processing device 2 and conveys it while maintaining the liquid pile state, and then moves it into the supercritical processing device 4. The supercritical processing device 4 performs a drying process (supercritical drying process) using a processing fluid in a supercritical state on the substrate that has been moved in. These are all arranged in a clean room. Therefore, the substrate conveying device 3 conveys the substrate S under ambient gas and atmospheric pressure.

[0044] The control device 9 controls the actions of these devices to achieve the prescribed processing. For this purpose, the control device 9 has a CPU 91, a memory 92, a storage 93, and an interface 94. The CPU 91 executes various control programs. The memory 92 temporarily stores processing data. The storage 93 stores the control program executed by the CPU 91. The interface 94 exchanges information with a user or an external device. The actions of the devices described below are achieved by the CPU 91 executing the control program written in advance to the storage 93, so that each part of the device performs a prescribed action.

[0045] By making the CPU 91 execute a predetermined control program, the control device 9 realizes, by software operation, functional blocks such as a wet processing control unit 95 for controlling the operation of the wet processing device 2, a transport control unit 96 for controlling the operation of the substrate transport device 3, and a supercritical processing control unit 97 for controlling the operation of the supercritical processing device 4. In addition, at least a part of each of these functional blocks may also be constructed using dedicated hardware.

[0046] As the "substrate" in this embodiment, various substrates such as semiconductor wafers, glass substrates for masks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FED (Field Emission Display), substrates for optical disks, substrates for magnetic disks, and substrates for optical magneto-magnetic disks can be applied. Hereinafter, a substrate processing device mainly used for processing a disk-shaped semiconductor wafer is described as an example with reference to the accompanying drawings. However, it can also be applied to the processing of various substrates exemplified above. In addition, various substrate shapes can also be applied.

[0047] In addition, in the following description, a substrate having a pattern formed only on one main surface is used as an example. Here, the main surface side having the pattern formed thereon is referred to as the "front surface", and the main surface on the opposite side without the pattern formed thereon is referred to as the "back surface". In addition, the main surface of the substrate facing downward is referred to as the "lower surface", and the main surface of the substrate facing upward is referred to as the "upper surface". In addition, the upper surface is referred to as the surface in the following description.

[0048] Figure 2A as well as Figure 2B : is a diagram showing an example of the configuration of a wet processing device. More specifically, Figure 2A is a side view showing the overall structure of the wet processing device, Figure 2B 2 is a diagram for explaining the operation of the wet processing apparatus. The wet processing apparatus 2 is an apparatus for processing the substrate S by supplying a processing liquid to the surface of the substrate S. The operation of the wet processing apparatus 2 is controlled by a wet processing control unit 95 of the control device 9.

[0049] The wet processing device 2 supplies a processing liquid to the surface (pattern forming surface) Sa of the substrate S, and performs various processes (chemical liquid treatment, preliminary organic solvent supply treatment, rinsing treatment, replacement treatment, and liquid film formation treatment, etc.) described in detail later. For this purpose, the wet processing device 2 has a substrate holding portion 21, a splash shield 22, and a processing liquid supply portion 23, 24 inside the processing chamber 200. These actions are controlled by a wet processing control portion 95 provided in the control device 9. The substrate holding portion 21 has a circular plate-shaped rotating chuck 211 having a diameter substantially equal to that of the substrate S, and a plurality of chuck pins 212 are provided on the peripheral portion of the rotating chuck 211.

[0050] Figure 3 2 is a diagram schematically showing the structure and operation of the chuck pin, wherein (a) in the same figure shows the chuck pin in the engaged state (clamped state), and (b) in the same figure shows the chuck pin in the unengaged state (released state). Although the illustration is omitted, in the present embodiment, 12 chuck pins 212 are radially arranged around the rotation axis AX of the rotating chuck 211. Each chuck pin 212 is arranged on the upper surface of the peripheral portion of the rotating chuck 211 so as to be freely movable in the radial direction D. The "radial direction D" mentioned here refers to the long side direction of the imaginary line connecting the rotation axis AX and the chuck pin 212.

[0051] The plurality of chuck pins 212 all have the same structure. Therefore, the structure of one chuck pin 212 is described below, and the same reference numerals are used for the components of the other chuck pins 212 and the description thereof is omitted. Figure 3 As shown, there is a chuck abutment surface 212a. The chuck abutment surface 212a is capable of moving along the radial direction D on the upper surface of the peripheral portion of the rotating chuck 211. As for the chuck pin 212, a lower abutment surface 212b is provided above the chuck abutment surface 212a. The lower abutment surface 212b is inclined downward as it tends to the direction (+D) toward the side of the rotation axis AX. A curved abutment surface 212c is provided upward from the end of the (-D) direction side of the lower abutment surface 212b. The curved abutment surface 212c is ultimately formed into a curved surface toward the side of the rotation axis AX. Moreover, an upper abutment surface 212d is provided extending upward from the upper end of the curved abutment surface 212c. The upper abutment surface 212d is inclined upward as it tends to the direction (+D) toward the side of the rotation axis AX. In more detail, as Figure 3As shown, the curved abutting surface 212c is directly continuous with the upper abutting surface 212d and the lower abutting surface 212b in a state where it is arranged between the upper abutting surface 212d and the lower abutting surface 212b. Therefore, if the substrate abutting portion 212e connected to the upper abutting surface 212d, the curved abutting surface 212c and the lower abutting surface 212b and abutting against the substrate S is observed from a horizontal direction orthogonal to the radial direction D, the substrate abutting portion 212e has a substantially C-shaped shape. In other words, the chuck pin 212 can reciprocate along the radial direction D in a state where the substrate abutting portion 212e is directed toward the rotation axis AX.

[0052] The chuck pin 212 is connected to the chuck driving unit 215. The chuck driving unit 215 moves the chuck pin 212 in the radial direction D according to the instruction from the wet processing control unit 95. Figure 3 As shown in (b) of the figure, the chuck drive unit 215 moves the chuck pin 212 in the direction (-D) and positions it in the non-engaged position. At this time, the curved abutting surface 212c and the upper abutting surface 212d are separated from the rotation axis AX by a distance slightly larger than the radius of the substrate S. On the other hand, the lower abutting surface 212b is located below the substrate S. Therefore, as shown in (b) of the figure, the substrate S is supported only by the lower abutting surface 212b, and is supported only at a position in the lower abutting surface 212b that is separated from the curved abutting surface 212c on the (+D) direction side.

[0053] On the other hand, when the substrate S is engaged, Figure 3 As shown in (a), the chuck driving unit 215 moves the chuck pin 212 in the direction (+D) and positions it at the engaging position. By moving the chuck pin 212 from the non-engaging position to the engaging position, the supporting position of the substrate S on the lower abutting surface 212b is displaced in the (-D) direction. When the movement of the chuck pin 212 to the engaging position is completed, the substrate S is supported by the lower abutting surface 212b, the curved abutting surface 212c and the upper abutting surface 212d. In other words, the substrate engagement is completed.

[0054] When the engagement of the substrate S is released, the chuck pin 212 is moved in the reverse order to the above, and the support position of the substrate S on the lower contact surface 212 b is displaced in the (+D) direction.

[0055] In addition, by moving the supporting position of the substrate S on the lower abutting surface 212b in the radial direction D, the height position of the substrate S in the vertical direction Z is displaced by only a distance dz. Therefore, if the wet processing control unit 95 gives a reciprocating movement instruction to the chuck drive unit 215, the chuck pin 212 moves back and forth in the radial direction D, and repeatedly lifts and lowers the substrate S synchronously therewith. In other words, it is possible to give vibration in the up and down directions relative to the substrate S. In addition, in the present embodiment, the purpose of the present invention is achieved by using this vibration addition. In this regard, a chuck pin 212 capable of vibration addition is used, but an existing chuck pin that does not have a vibration addition function may also be used.

[0056] Back to Figure 2A as well as Figure 2B , the structure of the wet processing device 2 is described. The rotating chuck 211 is supported by a rotating spindle 213 extending downward from the central part of its lower surface so that the upper surface is horizontal. The rotating spindle 213 is supported by a rotating mechanism 214 installed at the bottom of the processing chamber 200 so that it can rotate freely. The rotating mechanism 214 is equipped with a rotating motor not shown in the figure. By rotating the rotating motor according to the control command from the control device 9, the rotating chuck 211 directly connected to the rotating spindle 213 is rotated around the rotation axis AX shown by the single-point chain line. In Figure 2, the up and down direction is the vertical direction. As a result, the substrate S rotates around the rotation axis AX while maintaining a horizontal posture.

[0057] The splash shield 22 is provided so as to surround the substrate holding portion 21 from the side. The splash shield 22 has a substantially cylindrical cup portion 221 provided so as to cover the peripheral portion of the rotation chuck 211, and a liquid receiving portion 222 provided below the outer peripheral portion of the cup portion 221. The cup portion 221 is raised and lowered according to a control command from the control device 9. The cup portion 221 is raised and lowered between a lower position and an upper position, and the lower position is as shown in FIG. Figure 2A As shown in FIG. 1 , the upper end of the cup portion 221 is lowered to a position lower than the peripheral edge of the substrate S held on the rotating chuck 211, and the upper position is as shown in FIG. Figure 2B As shown in FIG. 1 , the upper end portion of the cup portion 221 is located above the peripheral edge portion of the substrate S. As shown in FIG.

[0058] When the cup portion 221 is in the lower position, Figure 2A As shown, the substrate S held by the spin chuck 211 is exposed to the outside of the cup portion 221. For this reason, for example, when the substrate S is carried in and out of the spin chuck 211, the cup portion 221 is prevented from causing an obstacle.

[0059] In addition, when the cup portion 221 is located at the upper position, as shown in FIG. Figure 2BAs shown, the cup 221 surrounds the periphery of the substrate S held by the spin chuck 211. In this way, the processing liquid thrown out from the periphery of the substrate S during the liquid supply described later is prevented from splashing into the processing chamber 200, and the processing liquid can be reliably recovered. That is, the droplets of the processing liquid thrown out from the periphery of the substrate S by rotating the substrate S adhere to the inner wall of the cup 221 and flow downward, and are collected and recovered by the liquid receiving portion 222 disposed below the cup 221. In order to independently recover a variety of processing liquids, a multi-stage cup is concentrically provided.

[0060] The processing liquid supply unit 23 has a structure in which a nozzle 234 is installed at the front end of an arm 233 extending horizontally from a rotating main shaft 232 that is rotatably provided relative to a base 231 fixed to the processing chamber 200. By rotating the rotating main shaft 232 according to the control command from the control device 9, the arm 233 is shaken, and the nozzle 234 at the front end of the arm 233 is moved as shown in FIG. Figure 2A The retreat position of retreating from the upper side of the substrate S as shown in FIG. Figure 2B The substrate S is shown moving between processing positions above the substrate.

[0061] The nozzle 234 is connected to the processing liquid supply source 238. When a suitable processing liquid is delivered from the processing liquid supply source 238, the processing liquid is sprayed toward the substrate S from the nozzle 234. Figure 2B As shown, while the substrate S is rotated by rotating the spin chuck 211 at a relatively low speed, the processing liquid L1 is supplied from the nozzle 234 positioned above the rotation center of the substrate S, thereby the surface Sa of the substrate S is processed by the processing liquid L1. As the processing liquid L1, liquids having various functions such as a chemical liquid (developer, etching liquid, cleaning liquid, etc.) and a rinse liquid can be used, and the composition thereof is arbitrary. In addition, a plurality of processing liquids can be combined to perform processing.

[0062] The other processing liquid supply unit 24 also has a configuration corresponding to the first processing liquid supply unit 23. That is, the second processing liquid supply unit 24 has a base 241, a rotation spindle 242, an arm 243, a nozzle 244, etc., and these configurations are the same as the corresponding configurations in the first processing liquid supply unit 23. The rotation spindle 242 rotates according to the control command from the control device 9, thereby causing the arm 243 to shake. The nozzle 244 at the front end of the arm 243 supplies the processing liquid relative to the surface Sa of the substrate S.

[0063] In this embodiment, the second processing liquid supply unit 24 is used to perform preliminary organic solvent supply processing, replacement processing and liquid film formation processing. That is, the substrate S after wet processing is transported to the supercritical processing device 4 to receive supercritical drying processing, but in order to prevent the surface of the substrate S from being exposed and oxidized during the transportation period, or the fine pattern formed on the surface from collapsing, the substrate S is transported in a state where the surface is covered with a paddle-shaped liquid film.

[0064] As the liquid constituting the liquid film, a substance having a surface tension smaller than that of water, which is the main component of the treatment liquid used in the chemical treatment, such as an organic solvent such as isopropyl alcohol (IPA) or acetone is used. These organic solvents are supplied from an organic solvent supply source 248 .

[0065] In addition, in this embodiment, the organic solvent is supplied not only during the liquid film forming process but also during the preliminary organic solvent supply process from the second processing liquid supply unit 24 to the substrate S. This is for the purpose of removing the residual liquid, which will be described later. Figure 6 as well as Figure 7 Describe it in detail.

[0066] Here, two groups of processing liquid supply parts are provided in the wet processing device 2, but the number of processing liquid supply parts, their structure, and functions are not limited thereto. For example, there may be only one group of processing liquid supply parts, or there may be more than three groups. In addition, a processing liquid supply part may have multiple nozzles. For example, multiple nozzles may be provided at the front end of an arm. In addition, this may include not only a form in which the nozzle sprays the processing liquid in a state where the nozzle is positioned at a specified position, but also a form in which the nozzle sprays the processing liquid while scanning and moving along the surface Sa of the substrate S.

[0067] return Figure 1 The substrate transport device 3 is provided with a transport robot 30 having a hand 31 at the front end of a telescopic / rotatable arm. The hand 31 can support the substrate S by partially contacting the back side of the substrate S. Figure 1 As shown by the dotted lines, the hand 31 can move freely forward and backward relative to both the wet processing device 2 and the supercritical processing device 4. Thus, the substrate can be carried in and out of the wet processing device 2 and the supercritical processing device 4, respectively. The movement of the transport robot 30 is controlled by the transport control unit 96 of the control device 9. There are many known technologies for this type of transport robot, which can also be appropriately selected and used in this embodiment, so detailed description is omitted.

[0068] Figure 4 4 is a side view showing the structure of the supercritical processing device. The supercritical processing device 4 is a device for performing a drying process using a processing fluid in a supercritical state on a substrate S after a wet process. More specifically, the supercritical processing device 4 is a device for receiving a substrate S after a wet process, displacing the liquid remaining on the substrate S with a processing fluid in a supercritical state, and then discharging the processing fluid, thereby finally making the substrate S reach a dry state.

[0069] The supercritical treatment device 4 has a treatment unit 41, a transfer unit 43 and a supply unit 45. The treatment unit 41 becomes the main body for executing the supercritical drying treatment. The transfer unit 43 receives the substrate S after the wet treatment transported by the substrate transport device 3 and transports it into the treatment unit 41, and then delivers the treated substrate S from the treatment unit 41 to the external transport device. The supply unit 45 supplies the chemical substances, power and energy required for the treatment to the treatment unit 41 and the transfer unit 43. These actions are controlled by the control device 9, especially by the supercritical treatment control unit 97.

[0070] The processing unit 41 has a structure in which a processing chamber 412 is installed on a pedestal 411. The processing chamber 412 is composed of a combination of several metal blocks, and its interior is hollow, forming a processing space SP. The substrate S to be processed is moved into the processing space SP and processed. A slit-shaped opening 421 extending elongatedly along the X direction is formed on the (-Y) side of the processing chamber 412. The processing space SP is connected to the external space through the opening 421. The cross-sectional shape of the processing space SP is roughly the same as the opening shape of the opening 421. That is, the processing space SP has a cross-sectional shape that is long in the X direction and short in the Z direction, and is a hollow extending along the Y direction.

[0071] A cover member 413 is provided on the (-Y) side of the processing chamber 412 in a manner of closing the opening 421. The cover member 413 closes the opening 421 of the processing chamber 412, thereby forming an airtight processing container. As a result, the substrate S can be processed under high pressure in the internal processing space SP. On the (+Y) side of the cover member 413, a flat support tray 415 is installed in a horizontal posture. The upper surface of the support tray 415 serves as a support surface on which the substrate S can be placed. The cover member 413 is supported by a support mechanism (not shown) so as to be freely movable horizontally in the Y direction.

[0072] The cover member 413 can be moved forward and backward relative to the processing chamber 412 by an advance and retreat mechanism 453 provided in the supply unit 45. Specifically, the advance and retreat mechanism 453 has a direct-acting mechanism such as a linear motor, a direct-acting guide rail, a ball screw mechanism, a solenoid valve, a cylinder, etc. Such a direct-acting mechanism moves the cover member 413 in the Y direction. The advance and retreat mechanism 453 operates according to a control command from the control device 9.

[0073] The cover member 413 is separated from the processing chamber 412 by moving in the (-Y) direction. As shown by the dotted line, if the support tray 415 is pulled out from the processing space SP through the opening 421, the support tray 415 can be contacted. That is, the substrate S can be placed on the support tray 415, and the substrate S placed on the support tray 415 can be taken out. On the other hand, by moving the cover member 413 in the (+Y) direction, the support tray 415 is accommodated in the processing space SP. When the support tray 415 is loaded with the substrate S, the substrate S is carried into the processing space SP together with the support tray 415.

[0074] Figure 5 4 is a perspective view showing the structure of the support tray. The support tray 415 has a tray member 416 and a plurality of support pins 417. The tray member 416 has a structure in which a recessed portion 418 is provided on a horizontal and flat upper surface of a flat plate-shaped structure, for example, and the recessed portion 418 has a diameter corresponding to the plane size of the substrate S, more specifically, a diameter slightly larger than the diameter of the circular substrate S.

[0075] The recessed portion 418 partially extends to the side surface of the tray member 416. That is, the side wall surface of the recessed portion 418 is not round, but partially cut out. Therefore, in the cut-out portion, a part of the bottom surface 418a of the recessed portion 418 is directly connected to the side surface. In this example, such cut-out portions are provided at both ends on the X side and the (+Y) side of the support tray 415, and in these locations, the bottom surface 418a is directly connected to the side surface.

[0076] In addition, a through hole 419 for inserting the lifting pin 437 is formed in the bottom surface 418a at a position corresponding to the lifting pin 437 of the transfer unit 43. By passing the lifting pin 437 through the through hole 419 and lifting and lowering it, the substrate S is accommodated in the recessed portion 418 and lifted upward in this state.

[0077] A plurality of support pins 417 are disposed at the periphery of the recessed portion 418. The number of support pins 417 is arbitrary, but preferably three or more are provided from the viewpoint of stably supporting the substrate S. In the present embodiment, three support pins 417 are mounted on the tray member 416 so as to surround the bottom surface 418a when viewed from above. Figure 5 As shown in the partially enlarged view in FIG. 1 , the support pin 417 has a height limiting portion 417 a and a horizontal position limiting portion 417 b.

[0078] The upper surface of the height limiting portion 417a is flat, and by contacting the peripheral edge of the back side of the substrate S, the substrate S is supported and its position in the vertical direction Z (hereinafter referred to as "height position") is indicated. On the other hand, the horizontal position limiting portion 417b extends above the upper end of the height limiting portion 417a and contacts the side surface of the substrate S, thereby limiting the horizontal direction (XY direction) position of the substrate S. By using such a supporting pin 417, the substrate S is supported in a horizontal posture separated from the bottom surface 418a upward while being opposed to the bottom surface 418a of the recessed portion 418.

[0079] The cover member 413 blocks the opening 421 by moving in the (+Y) direction, thereby sealing the processing space SP. A sealing member 422 is provided between the (+Y) side surface of the cover member 413 and the (-Y) side surface of the processing chamber 412 to maintain the airtight state of the processing space SP. The sealing member 422 is made of rubber, for example. In addition, the cover member 413 is fixed relative to the processing chamber 412 by a locking mechanism not shown. As described above, in the present embodiment, the cover member 413 switches between a closed state (solid line) in which the opening 421 is closed to seal the processing space SP, and a separated state (dashed line) in which the cover member 413 is greatly separated from the opening 421 to allow the substrate S to enter and exit.

[0080] While ensuring the airtight state of the processing space SP, processing of the substrate S is performed in the processing space SP. In the present embodiment, the fluid supply part 457 provided in the supply unit 45 delivers a processing fluid of a substance that can be used for supercritical processing, such as carbon dioxide, as a processing fluid, to further pressurize the processing fluid in the processing chamber 412, thereby reaching a supercritical state. The processing fluid is supplied to the processing unit 41 in a gas or liquid state. Carbon dioxide is a preferred chemical substance for supercritical drying processing because it becomes a supercritical state at a relatively low temperature and low pressure, and has the property of dissolving organic solvents commonly used in substrate processing well. The critical point at which carbon dioxide becomes a supercritical state is a gas pressure (critical pressure) of 7.38 MPa and a temperature (critical temperature) of 31.1°C.

[0081] The processing fluid is filled into the processing space SP. When the processing space SP reaches an appropriate temperature and pressure, the processing space SP is filled with the processing fluid in a supercritical state. Thus, the substrate S is processed in the processing chamber 412 using the processing fluid in a supercritical state. The supply unit 45 is provided with a fluid recovery unit 455, and the processed fluid is recovered by the fluid recovery unit 455. The fluid supply unit 457 and the fluid recovery unit 455 are controlled by the supercritical processing control unit 97.

[0082] The processing space SP has a shape and a volume that can receive the support tray 415 and the substrate S supported by the support tray 415. That is, the processing space SP has a roughly rectangular cross-sectional shape that is larger than the width of the support tray 415 in the horizontal direction and larger than the height of the support tray 415 and the substrate S in the vertical direction, and a depth that can receive the support tray 415. In this way, the processing space SP has a shape and a volume that can only receive the support tray 415 and the substrate S. However, the gap between the support tray 415 and the substrate S and the inner wall surface of the processing space SP is very small. Therefore, a relatively small amount of processing fluid required to fill the processing space SP is sufficient.

[0083] The fluid supply unit 457 supplies the processing fluid to the processing space SP at a position closer to the (+Y) side than the (+Y) side end of the substrate S. On the other hand, the fluid recovery unit 55 discharges the processing fluid flowing in the space above the substrate S and the space below the support tray 415 in the processing space SP at a position closer to the (-Y) side than the (-Y) side end of the substrate S. Thus, in the processing space SP, laminar flows of the processing fluid from the (+Y) side toward the (-Y) side are formed above the substrate S and below the support tray 415, respectively.

[0084] The supercritical processing control unit 97 of the control device 9 determines the pressure and temperature in the processing space SP based on the detection result of the detection unit (not shown), and controls the fluid supply unit 457 and the fluid recovery unit 455 based on the result. Thus, the supply of the processing fluid to the processing space SP and the discharge of the processing fluid from the processing space SP are appropriately managed and adjusted according to the processing process to achieve the specified pressure and temperature in the processing space SP.

[0085] The transfer unit 43 is responsible for the transfer of the substrate S between the substrate transport device 3 and the support tray 415. To achieve this purpose, the transfer unit 43 has a main body 431, a lifting member 433, a base member 435, and a plurality of lifting pins 437. The lifting member 433 is a columnar member extending in the Z direction, and is supported to be movable in the Z direction relative to the main body 431 by a supporting mechanism not shown in the figure. A base member 435 having a substantially horizontal upper surface is installed on the upper part of the lifting member 433. A plurality of lifting pins 437 are vertically arranged upward from the upper surface of the base member 435. The lifting pins 437 support the substrate S in a horizontal posture from below by making their upper ends abut against the back of the substrate S. In order to stably support the substrate S in a horizontal posture, it is preferred to provide three or more lifting pins 437 whose upper ends have the same height as each other.

[0086] The lifting member 433 can be lifted and lowered by a lifting mechanism 451 provided in the supply unit 45. Specifically, the lifting mechanism 451 has a direct-acting mechanism such as a linear motor, a direct-acting guide rail, a ball screw mechanism, a solenoid valve, and a cylinder, and such a direct-acting mechanism moves the lifting member 433 in the Z direction. The lifting mechanism 451 operates according to a control command from the control device 9.

[0087] The lifting member 433 is lifted and lowered to move the base member 435 up and down, and the plurality of lifting pins 437 move up and down together with the base member 435. Thus, the substrate S is transferred between the transfer unit 43 and the support tray 415. More specifically, as Figure 5 As shown by the dotted line, the substrate S is delivered in a state where the support tray 415 is pulled out of the chamber. To achieve this purpose, the support tray 415 is provided with a through hole 419 for inserting the lifting pin 437. When the base member 435 rises, the upper end of the lifting pin 437 passes through the through hole 419 and reaches above the upper surface of the support tray 415. In this state, the substrate S transported by the transport robot 30 is delivered from the hand 31 of the transport robot 30 to the lifting pin 437. By lowering the lifting pin 437, the substrate S is delivered from the lifting pin 437 to the support tray 415. The substrate S can be carried out in the reverse order to the above.

[0088] Figure 6 1 is a flowchart showing an overview of the processing performed by the substrate processing system of the first embodiment. The substrate processing system 1 receives a substrate S to be processed, and sequentially performs a wet processing using a processing liquid such as a chemical solution, a rinse liquid, and an organic solvent, a transport processing of transporting the substrate S after the wet processing from a wet processing device 2 to a supercritical processing device 4, and a supercritical drying processing using a supercritical processing fluid. Specifically, when the substrate S to be processed is accommodated in the wet processing device 2 constituting the substrate processing system 1 (step S10), the wet processing (step S20), the transport processing (step S30), and the supercritical drying processing (step S40) are sequentially performed.

[0089] The wet processing device 2 performs wet processing on the substrate S using a prescribed processing liquid (step S20). In the present embodiment, on the basis of the previous liquid treatment (step S21), rinse treatment (step S23), replacement treatment (step S24) and liquid film formation treatment (step S25), a preliminary organic solvent supply process (step S22) for supplying the above-mentioned organic solvent is also performed. The preliminary organic solvent supply process is performed between the liquid treatment and the rinse treatment. That is, in the wet processing, after the prescribed liquid treatment is performed by supplying a liquid such as a developer or a cleaning solution in step S21, an organic solvent such as IPA or acetone is supplied to the surface Sa of the substrate S (step S22). Next, a rinse liquid such as DIW (deionized water) is supplied to the surface Sa of the substrate S, and an organic solvent such as IPA is supplied to the substrate S, thereby replacing the rinse liquid attached to the surface Sa of the substrate S with an organic solvent (step S24), and forming a liquid pile state with an organic solvent. That is, the liquid film LF is formed on the surface Sa of the substrate S (step S25: liquid film forming process).

[0090] Here, refer to Figure 7 The significance of the technology of the liquid film forming process and the preliminary organic solvent supply process will be described. Figure 7 Schematically showing the difference in liquid film structure caused by the presence or absence of the preliminary organic solvent supply process. Figure 7 Column (a) shows the prior art in which the preliminary organic solvent supply process is not performed, and column (b) shows the embodiment in which the preliminary organic solvent supply process is performed. Figure 7 As shown, when DIW exists inside the pattern PT formed on the surface Sa of the substrate S, there is a concern that the pattern PT may collapse due to the surface tension of DIW. In addition, watermarks may remain on the surface Sa of the substrate S due to incomplete drying. Moreover, the surface Sa of the substrate S may be deteriorated by oxidation due to contact with the outside air. In order to prevent such problems from happening, the surface Sa of the substrate S is covered with an organic solvent. As the organic solvent, it is preferred to use a liquid with a lower surface tension than DIW and a lower corrosiveness to the substrate S, such as IPA, acetone, and other solvents that are compatible with DIW. The following describes a case where DIW is used as a rinse liquid and IPA is used as an organic solvent.

[0091] Here, when the replacement with IPA is performed well, the liquid film LF is formed by only IPA or a mixture of IPA and DIW. In this case, no DIW remains on the inner bottom surface of the pattern PT. However, in reality, as in the conventional example Figure 7As shown in (a), residual liquid (DIW) may remain on the inner bottom surface of the pattern PT. The specific gravity of the residual liquid is greater than that of the organic solvent, and it is easy to remain on the inner bottom surface of the pattern PT.

[0092] Therefore, in this embodiment, IPA is supplied to the surface Sa of the substrate S between the chemical treatment (step S21) and the rinse treatment (step S22). Thus, in the pattern PT, the following five liquid layers LL1 to LL5 are stacked in order from the inner bottom surface side:

[0093] Liquid layer LL1 = IPA layer composed of IPA used in the preliminary organic solvent supply process,

[0094] Liquid layer LL2 = a mixed layer of IPA and DIW used in the preliminary organic solvent supply process,

[0095] Liquid layer LL3 = layer of residual liquid consisting of DIW,

[0096] Liquid layer LL4 = a mixed layer of IPA and DIW used in the replacement process, liquid layer LL5 = an IPA layer composed of IPA used in the replacement process.

[0097] In addition, the liquid layer LL5 may include a part of IPA used in the liquid film formation process.

[0098] As described above, the liquid layer LL3 (that is, the residual liquid (DIW)) in the pattern PT exists in a state of being sandwiched by the liquid layers LL2 and LL4 including IPA. The DIW constituting the residual liquid diffuses between the liquid layers LL2 and LL4 during the period of being transported to the supercritical processing device 4 by the substrate transport device 3 as described below. As a result, the liquid layer LL3 consisting only of the residual liquid is removed. Thus, a liquid film LF without residual liquid is formed on the surface Sa of the substrate S. Then, the substrate is transported from the wet processing device 2 to the supercritical processing device 4 by the substrate transport device 3 while maintaining the liquid stack state (step S30).

[0099] The substrate S transported to the supercritical processing device 4 is stored in the processing chamber 412 while maintaining the liquid stacking state. Specifically, the substrate S is transported with the pattern forming surface (surface Sa) as the upper surface and the pattern forming surface is covered by a very thin liquid film LF. Figure 4As shown by the dotted line, when the cover member 413 moves to the (-Y) side and the support tray 415 is pulled out, the lifting pins 437 rise. The transport device delivers the substrate S to the lifting pins 437. When the lifting pins 437 are lowered, the substrate S is placed inside the support tray 415. When the support tray 415 and the cover member 413 move in the (+Y) direction as a whole, the support tray 415 supporting the substrate S is accommodated in the processing space SP in the processing chamber 412, and the opening 421 is closed by the cover member 413.

[0100] In this state, carbon dioxide as a processing fluid is introduced into the processing space SP in a gas phase (step S41). When the substrate S is carried in, the outside air invades the processing space SP, but it can be replaced by introducing the gas phase processing fluid. In addition, by injecting the gas phase processing fluid, the pressure in the processing chamber 412 is increased.

[0101] In addition, during the process of introducing the processing fluid, the processing fluid from the processing space SP is continuously discharged. That is, during the period of introducing the processing fluid by the fluid supply unit 457, the fluid recovery unit 455 also discharges the processing fluid from the processing space SP. Thus, the processing fluid supplied to the processing space SP will not be retained in the processing space SP but will be discharged, and impurities such as residues entering the processing fluid are prevented from being attached to the substrate S again.

[0102] If the supply amount of the treatment fluid is greater than the discharge amount, the density of the treatment fluid in the treatment space SP increases, and the internal pressure of the chamber increases. On the contrary, if the supply amount of the treatment fluid is less than the discharge amount, the density of the treatment fluid in the treatment space SP decreases, and the pressure in the chamber is reduced. The supply of the treatment fluid to the treatment chamber 412 and the discharge from the treatment chamber 12 are carried out based on a supply and discharge process created in advance. That is, the control device 9 controls the fluid supply part 457 and the fluid recovery part 455 based on the supply and discharge process, thereby adjusting the supply / discharge timing and flow rate of the treatment fluid.

[0103] Figure 8 : is a diagram showing the pressure change in the processing chamber. When the processing fluid is carbon dioxide, the critical temperature is basically the same as the room temperature, so the temperature change during the processing is not large. Here, the phenomenon is explained by focusing on the pressure in the chamber, which makes the change more significant. From the state where the processing space SP is open to the atmosphere and the internal air pressure is the atmospheric pressure Pa, the processing fluid is introduced at time T1 after the processing space SP is sealed, and the internal pressure begins to rise.

[0104] The pressure of the processing fluid in the processing space SP rises and exceeds the critical pressure Pc (step S42), and the pressurization continues. At the time T2 when the critical pressure Pc is reached in the chamber, the processing fluid becomes a supercritical state in the chamber. That is, due to the phase change in the processing space SP, the processing fluid is transformed from the gas phase to the supercritical state. By filling the processing space SP with the processing fluid in the supercritical state, the IPA (or the mixed fluid of IPA and DIW) covering the substrate S is replaced by the processing fluid in the supercritical state. The IPA and the like freed from the surface of the substrate S are discharged from the processing chamber 412 together with the processing fluid in a state of being dissolved in the processing fluid, and are removed from the substrate S. That is, the processing fluid in the supercritical state has the function of replacing the IPA (or the mixed fluid of IPA and DIW) attached to the substrate S as the replacement object liquid, and discharging it to the outside of the processing chamber 412.

[0105] After the time T3 when the processing fluid is reliably transformed into the supercritical state, the processing space SP is filled with the processing fluid in the supercritical state for a predetermined time (steps S43 and S44), so that the replacement target liquid attached to the substrate S can be completely replaced and discharged out of the chamber. Figure 8 , the pressure Pm in the chamber is shown to be constant in the supercritical state, but the pressure may fluctuate within a range that does not fall below the critical pressure Pc.

[0106] At time T4, if the replacement of the replacement target liquid based on the processing fluid in the supercritical state in the processing chamber 412 is completed (judged as "yes" in step S44), the processing fluid in the processing space SP is discharged to dry the substrate S. Specifically, by increasing the discharge amount of the fluid from the processing space SP, the pressure in the processing chamber 12 filled with the processing fluid in the supercritical state is reduced (step S45).

[0107] In the decompression process, the supply of the processing fluid can be stopped, or a small amount of processing fluid can be continuously supplied. By decompressing the processing space SP from a state filled with the processing fluid in a supercritical state, the processing fluid undergoes a phase change from the supercritical state to a gas phase. By discharging the vaporized processing fluid to the outside, the substrate S becomes a dry state. At this time, the decompression speed is adjusted in a manner that does not produce a solid phase and a liquid phase due to a sudden drop in temperature. That is, after the decompression starts at time T4, the decompression is performed at a relatively low decompression speed until time T5 when the pressure reliably drops to the critical pressure Pc. As a result, the processing fluid in the processing space SP is directly vaporized from the supercritical state and discharged to the outside.

[0108] After the time T5 when the processing fluid is completely vaporized, the decompression rate is increased, thereby reducing the pressure to the atmospheric pressure Pa in a short time. In this way, during the entire period from the time T4 when the decompression starts to the time T6 when the pressure in the chamber drops to the atmospheric pressure Pa, the processing fluid will not liquefy, thereby avoiding the formation of a gas-liquid interface on the substrate S exposed on the surface after drying.

[0109] As described above, in the supercritical drying process of the present embodiment, after the processing space SP is filled with the processing fluid in a supercritical state, the gas phase is changed and discharged, thereby making it possible to efficiently replace the liquid attached to the substrate S and prevent the liquid from remaining on the substrate S. Furthermore, the substrate can be dried while avoiding problems such as contamination of the substrate due to the attachment of impurities, pattern collapse, and the formation of a gas-liquid interface.

[0110] The processed substrate S is carried out to the subsequent process (step S50). That is, by moving the cover member 413 in the (-Y) direction, the support tray 415 is pulled out from the processing chamber 412 to the outside, and the substrate S is delivered to the external conveying device via the transfer unit 43. At this time, the substrate S is in a dry state. The content of the subsequent process is arbitrary. In this way, the processing of a substrate S is completed. In the case where there is a substrate to be processed next, return to step S10 to receive a new substrate S, and repeat the above process.

[0111] As described above, according to the first embodiment, in the wet processing device 2, after the liquid treatment (step S21), the preliminary organic solvent supply process (step S22), the rinsing process (step S23), the replacement process (step S24), and the liquid film forming process (step S25) corresponding to an example of the "liquid accumulation process" of the present invention are sequentially performed. Here, even if DIW remains in the pattern PT of the pattern forming surface (surface Sa) of the substrate S in the liquid accumulation state, Figure 7 As shown in (b), the liquid layer LL3 composed of residual liquid is clamped by liquid layers LL2 and LL4, which are mixed layers of IPA and DIW, in the vertical direction. Therefore, the DIW constituting the liquid layer LL3 diffuses mutually between the liquid layers LL2 and LL4. In particular, there is sufficient time for the residual liquid (DIW) to diffuse mutually between the above-mentioned liquid layers LL2 and LL4 until the substrate S in the liquid pile state is transported to the supercritical processing device 4 and contacts the processing fluid in the supercritical state. Accordingly, the residual liquid is mixed with IPA through the above-mentioned mutual diffusion. Therefore, the drying process based on the processing fluid in the supercritical state is performed using the so-called residual liquid-free. This means that the processing fluid in the supercritical state will not be overused, and the supercritical drying process can be performed with high quality. As a result, the consumption of the processing fluid can be reduced while the yield can be increased.

[0112] As described above, in the first embodiment, DIW is equivalent to an example of the "rinsing liquid" of the present invention. In addition, IPA is equivalent to an example of the "organic solvent" of the present invention, and IPA is used as the "organic solvent" in the preliminary organic solvent supply process (step S22), the replacement process (step S24), and the liquid film formation process (step S25). The surface Sa of the substrate S is equivalent to the "pattern forming surface" of the present invention. In addition, steps S20, S30, and S40 are respectively equivalent to an example of the "(a) process", "(b) process", and "(c) process" of the present invention.

[0113] Furthermore, in the first embodiment, the substrate S is transported from the wet processing apparatus 2 to the supercritical processing apparatus 4 while maintaining a so-called sandwich structure in which the liquid layer LL3 corresponding to the residual liquid is sandwiched by the liquid layers LL2 and LL4. Here, vibration may be applied to the substrate S before or during the transport and / or before the processing fluid is supplied to the supercritical processing apparatus 4. The vibration is used to promote mutual diffusion between the DIW constituting the liquid layer LL3 and the liquid layers LL2 and LL4, so that the residual liquid can be removed in a shorter time.

[0114] Fig. 9 2 is a flowchart showing the operation of the second embodiment of the substrate processing system of the present invention. In the first embodiment, the chuck pin 212 has a vibration function in addition to the function of clamping the side end of the substrate S to hold the substrate S. Therefore, in the second embodiment, for example Fig. 9 As shown, the substrate S may be vibrated (step S60) after the liquid film formation process (step S25) and before the substrate is transported (step S30). More specifically, after the liquid accumulation state is formed in the wet processing device 2, the wet processing control unit 95 gives a reciprocating movement instruction to the chuck driving unit 215. Thus, Figure 3 (a) shows the engagement state and Figure 3 The non-engaging state shown in (b) is repeated alternately. That is, the substrate S is repeatedly raised and lowered with the reciprocating movement of the chuck pin 212 in the radial direction D. Fig. 9 As shown in the lower left figure, the vibration in the vertical direction Z is added to the substrate S, and the residual liquid (DIW) constituting the liquid layer LL3 is transferred and diffused to the liquid layers LL2 and LL4, and the DIW contained in the liquid layers LL2 and LL4 is also transferred and diffused to the liquid layers LL1 and LL5, respectively. In this way, the liquid layer LL3 disappears in a shorter time than in the first embodiment, and the DIW diffuses to the entire liquid film LF (step S60). In addition, in this specification, the process of removing the residual liquid by adding vibration like this is called "residual liquid removal process".

[0115] In the second embodiment, a vibration adding function is required to perform the residual liquid removal process, and the chuck pin 212 performs this function. Therefore, there is no need to add a structure dedicated to the vibration adding function, so the cost of the device can be reduced.

[0116] In the second embodiment, in order to perform the residual liquid removal process, the substrate S is vibrated in the vertical direction Z, but the additional form of vibration is not limited to this. For example, the wet processing control unit 95 may give a positive and negative rotation command to the rotating mechanism 214 while the substrate S is held by the chuck pin 212. In this case, the rotating mechanism 214 that has received the positive and negative rotation command repeatedly rotates the substrate S around the rotation axis AX at a predetermined angle, that is, repeatedly performs a rotation action. In this way, the substrate S can be vibrated by rotating the substrate S in the circumferential direction.

[0117] In addition, instead of adding vibration of the chuck pin 212 along the vertical direction Z (hereinafter referred to as "additional up and down vibration"), or adding vibration of the rotating mechanism 214 along the circumferential direction (hereinafter referred to as "additional rotational vibration"), it is also possible to use another additional structure to add vibration to the substrate S. For example, after the liquid film formation process (step S25), the wet processing control unit 95 can operate an ultrasonic transducer located at a position separated from the substrate holding unit 21, and the ultrasonic wave generated by the ultrasonic transducer can vibrate the substrate S. In addition, the vibrator can be installed on the substrate holding unit 21 in advance, and after the liquid film formation process (step S25), the wet processing control unit 95 can operate the vibrator. In these embodiments, the vibration direction of the substrate S can be controlled according to the setting form of the vibrator. In addition, with respect to the vibrator and the ultrasonic transducer, existing well-known equipment can be used. Therefore, a detailed description of the structure is omitted in this specification.

[0118] Furthermore, in the second embodiment described above, vibration is applied to the substrate S in the liquid-filled state in the wet processing apparatus 2 , but vibration may be applied to the substrate transport apparatus 3 or the supercritical processing apparatus 4 .

[0119] For example, in the first embodiment and the fifth embodiment, the transport robot 30 can move freely forward and backward relative to both the wet processing device 2 and the supercritical processing device 4 while supporting the substrate S in the liquid-filled state from the back side. Therefore, the transport robot 30 not only has the function of carrying the substrate S in and out of the wet processing device 2 and the supercritical processing device 4, but also can make the hand 31 supporting the substrate S move back and forth or rotate in the horizontal direction. In other words, by repeatedly moving the hand 31 back and forth or rotating, vibration along the horizontal direction can be added to the substrate S. Therefore, the transport process (step S30) from the wet processing device 2 to the supercritical processing device 4 can also control the transport robot 30 in a manner of sequentially executing the following three sub-processes:

[0120] · A step in which the hand 31 receives the substrate S in a liquid-filled state,

[0121] A step of moving the hand 31 back and forth only a predetermined distance in a horizontal plane, or rotating the hand 31 in forward and reverse directions to add vibration to the substrate S while maintaining the substrate S in a liquid-filled state;

[0122] A step in which the transport robot 30 transports the substrate S in the liquid-filled state to the processing unit 41 of the supercritical processing apparatus 4 .

[0123] In addition, here, the residual liquid removal process is performed at the time point when the hand 31 enters the wet processing device 2 and receives the substrate S in the liquid accumulation state, but the timing of the execution of the residual liquid removal process is not limited to this. For example, during the process of the hand 31 moving to the supercritical processing device 4, the residual liquid removal process can be performed while the hand 31 stops and waits near the supercritical processing device 4.

[0124] In addition, in order to wait for the substrate S to be transported to the supercritical processing device 4 according to the operating status of the supercritical processing device 4, in addition to setting the vicinity of the supercritical processing device 4 as the waiting position, there are also cases where other waiting positions are set. For example, in the case where the substrate transport device 3 has a stage for temporarily placing the substrate S in the liquid-filled state to wait, the stage functions as the waiting position. Therefore, a vibrator can also be installed on the stage to add vibration to the substrate S waiting on the stage. In other words, the residual liquid removal process can also be performed at the waiting position provided with the stage.

[0125] In addition, in order to perform the residual liquid removal process, the hand 31 is vibrated in the horizontal direction or rotated in the horizontal plane, but vibration may be added in other forms by utilizing the structure of the transport robot 30. For example, the transport robot 30 may be configured to move the hand 31 in the vertical direction Z. In this case, the substrate S is vibrated by raising and lowering the hand 31 of the substrate S holding the liquid-filled state in the vertical direction Z.

[0126] In the first embodiment and the second embodiment, the substrate S transported to the supercritical processing device 4 is stored in the processing chamber 412 while maintaining the liquid state. Specifically, the substrate S is transported with the pattern forming surface Sa as the upper surface and the pattern forming surface Sa is covered with a very thin liquid film LF. Figure 4 As shown by the dotted line, when the cover member 413 moves to the (-Y) side and the support tray 415 is pulled out, the lift pins 437 rise. The conveying device delivers the substrate S to the lift pins 437. By lowering the lift pins 437, the substrate S is placed on the support tray 415. In this way, the substrate S is received.

[0127] At this time, the supercritical process control unit 97 can reciprocate the support tray 415 and the cover member 413 in the Y direction while maintaining the substrate S in the liquid accumulation state. By applying vibration to the substrate S by this reciprocating movement, the residual liquid is transferred and diffused (residual liquid removal process) similarly to the second embodiment.

[0128] According to this embodiment, the residual liquid removal process is performed in the supercritical processing apparatus 4 before the processing fluid in the supercritical state is brought into contact with the substrate S. Therefore, the same operational effects as those of the second embodiment are obtained.

[0129] In addition, in this embodiment, the support tray 415 and the cover member 413 are vibrated in the Y direction to perform the residual liquid removal process, but a vibrator may be installed on the support tray 415 or the cover member 413. In other words, the vibrator may be operated according to a vibration command from the supercritical process control unit 97 to vibrate the substrate S.

[0130] In addition, the residual liquid removal process is performed before the pressure in the processing chamber 412 rises, but the residual liquid removal process can also be performed during the pressure rise as long as it is performed before reaching the supercritical condition. For example, the residual liquid removal process can be performed in a subcritical state. In particular, considering the elapsed time from the execution of the residual liquid removal process to the start of contact with the processing fluid in the supercritical state, it is preferred to perform the residual liquid removal process at a timing close to the subcritical state. That is, for reasons such as the specific gravity of DIW being greater than the specific gravity of IPA, as the above-mentioned elapsed time becomes longer, a portion of the DIW diffused into the IPA may precipitate onto the inner bottom surface of the pattern PT, resulting in an increase in the DIW concentration. Taking this into account, it is also preferred to set the execution timing of the residual liquid removal process.

[0131] In addition, a heating process for the pattern may be provided in place of the above-mentioned vibration addition, or a heating process for the pattern may be provided in addition to the above-mentioned vibration addition. For example, at least one of the following means may be performed:

[0132] (a) Use a flushing fluid that can maintain a temperature of 40°C or higher and below the upper limit of the stacking liquid state;

[0133] (b) In parallel with the liquid film forming process (liquid stacking process), high-temperature DIW or heated fluid (collectively referred to as "heating medium") is supplied to the back side Sb of the substrate S opposite to the pattern forming surface Sa. In addition, the heating medium preferably has an upper limit temperature that can maintain 80°C or more and be in a liquid stacking state;

[0134] (c) In parallel with the liquid film forming process (liquid stacking process), the substrate S is heated by a heater (not shown) disposed opposite to the back side Sb of the substrate S opposite to the pattern forming surface Sa;

[0135] (d) while heating the substrate S received from the wet processing apparatus 2 by a heater (not shown) provided in the hand 31 of the transfer robot 30, the substrate S is delivered to the supercritical processing apparatus 4 by the hand 31;

[0136] (e) In the supercritical processing apparatus 4 , before the processing fluid in a supercritical state is brought into contact with the substrate S to perform supercritical drying, the substrate S is heated by a heater (not shown) provided on the support tray 415 .

[0137] In addition, the present invention is not limited to the above-mentioned embodiment, and various changes other than the above-mentioned can be made within the scope of the main purpose. In the above-mentioned embodiment, IPA is used as an organic solvent in any of the processes of the preliminary organic solvent supply process (step S22), the replacement process (step S24), and the liquid film formation process (step S25). However, the combination of organic solvents used in each process is not limited to this, and multiple combinations can also be used. For example, acetone is used in one of the three processes, and IPA is used in the remaining processes.

[0138] In addition, various chemical substances used in the processing of the above-mentioned embodiment are shown as some examples, and various chemical substances can be used instead as long as they conform to the technical concept of the above-mentioned present invention.

[0139] The invention is described above along specific embodiments, but these descriptions are not intended to be interpreted in a limiting sense. As with other embodiments of the present invention, various modifications of the disclosed embodiments will be apparent to those skilled in the art by reference to the description of the invention. Therefore, the attached claims are considered to include such modifications or embodiments within the scope of the subject matter of the invention.

[0140] The present invention can be applied to all substrate processing methods and substrate processing systems for processing a substrate covered by a liquid film using a processing fluid in a supercritical state.

Claims

1. A substrate processing method for processing a substrate having a pattern forming surface on which a pattern is formed, the substrate processing method being characterized by comprising: (a) step, in a wet processing device, sequentially performing a liquid treatment of the substrate by supplying a liquid to the pattern forming surface, a preliminary organic solvent supplying process by supplying an organic solvent to the pattern forming surface, a rinsing process by supplying a rinsing liquid to the pattern forming surface, a replacement process by supplying the organic solvent to the pattern forming surface, and a liquid stacking process by stacking the organic solvent on the pattern forming surface; (b) a step of transporting the substrate from the wet processing apparatus to a supercritical processing apparatus while maintaining a state in which the organic solvent is deposited on the pattern forming surface by the deposit treatment; as well as (c) step of drying the substrate by bringing the pattern forming surface in the liquid-bank state into contact with a processing fluid in a supercritical state in the supercritical processing apparatus.

2. The substrate processing method according to claim 1, characterized in that: The organic solvent used in the preliminary organic solvent supply process, the organic solvent used in the replacement process, and the organic solvent used in the stack liquid process are of the same type.

3. The substrate processing method according to claim 2, characterized in that: The organic solvent used in the preliminary organic solvent supply process, the organic solvent used in the replacement process, and the organic solvent used in the stack liquid process are IPA, and IPA is isopropyl alcohol.

4. The substrate processing method according to claim 1, characterized in that: The method further comprises a step (d) in which, before the pattern forming surface is brought into contact with the processing fluid in the supercritical state, the substrate is vibrated while maintaining the liquid pile state, thereby mixing the rinse liquid remaining in the pattern with the organic solvent.

5. The substrate processing method according to claim 1, characterized in that: In at least one of the step (a), the step (b), and the step (c), the interior of the pattern is heated while maintaining the liquid accumulation state.

6. A substrate processing system for processing a substrate having a pattern forming surface on which a pattern is formed, the substrate processing system comprising: a wet processing device for sequentially performing a liquid treatment on the substrate by supplying a liquid to the pattern forming surface, a preliminary organic solvent supplying process by supplying an organic solvent to the pattern forming surface, a rinsing process by supplying a rinsing liquid to the pattern forming surface, a replacement process by supplying the organic solvent to the pattern forming surface, and a liquid accumulation process by forming a liquid accumulation state in which the organic solvent is accumulated on the pattern forming surface; a supercritical processing device for drying the substrate by bringing the pattern forming surface in the liquid-filled state into contact with a processing fluid in a supercritical state; as well as A substrate transport device transports the substrate from the wet processing apparatus to a supercritical processing apparatus while maintaining the liquid stack state.

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