JP2025032738A - SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING SYSTEM - Google Patents

Abstract

To provide a substrate processing system that transports a substrate in a state where an organic solvent is mounted onto a front surface of the substrate subjected to wet processing is conveyed from a wet processing device to a supercritical processing apparatus to dry the substrate by using a processing fluid in a supercritical state, capable of improving a yield while reducing an environmental load by reducing a consumption amount of the processing fluid.SOLUTION: A substrate processing method and a substrate processing system warm an inside of a pattern while maintaining a liquid mounting state. Thus, convection diffusion of a liquid component existing in the pattern is promoted. In other words, a remaining liquid existing at an inner bottom surface is also mixed to an organic solvent by performing the convection diffusion to the organic solvent. As a result, dry processing by a processing fluid in a supercritical state is executed in a state where the remaining liquid not exist on the inner bottom surface of the pattern, that is, in a remaining liquid free state.SELECTED DRAWING: Figure 6

Description

This invention relates to a technique for drying a substrate in a processing chamber, and in particular to a process for treating a substrate covered with a liquid film with a processing fluid in a supercritical state.

Processing processes for various substrates, such as semiconductor substrates and glass substrates for display devices, include processing the surface of the substrate with various processing fluids. Wet processing, which uses liquids such as chemicals and rinse fluids as processing fluids, has been widely used. In recent years, processing using processing fluids in a supercritical state has also been put to practical use in order to dry substrates after the wet processing. This is particularly useful in drying substrates having a patterned surface on which fine patterns are formed. This is because the processing fluid in a supercritical state has a lower surface tension than liquids and has the property of penetrating deep into the gaps in the pattern. By using this processing fluid, it is possible to perform the drying process efficiently. It is also possible to reduce the risk of pattern collapse due to surface tension during drying.

For example, in the substrate processing system described in Patent Document 1, a substrate developing device is provided as an example of the "wet processing device" of the present invention. In this substrate developing device, as a final process 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 rinsing liquid. This executes IPA replacement, and the rinsing liquid is removed from the surface of the substrate. In addition, a puddle state in which the IPA liquid is piled on the surface of the substrate is created. In other words, a liquid film containing the IPA liquid is formed in a puddle shape. As a result, the surface of the substrate is maintained in a wet state with the IPA liquid. Then, while maintaining the puddle state, the substrate is transported by a substrate transport device to a substrate drying device, which is an example of the "supercritical processing device" of the present invention, and a drying process is performed using a processing fluid in a supercritical state.

JP 2013-201302 A

In wet processing equipment such as substrate developing equipment and substrate cleaning equipment, it is desirable to completely drain liquids such as rinse liquid from inside the pattern by IPA replacement. However, liquid may remain on the inner bottom surface of the pattern. If the substrate is loaded into a substrate drying equipment (supercritical processing equipment) with such remaining liquid (hereinafter referred to as "residual liquid") remaining and a supercritical drying process is performed, the following problem may occur. In other words, the replacement of the liquid components that make up the liquid film with the processing fluid in a supercritical state is likely to be incomplete. Therefore, in order to cover this, a countermeasure of increasing the amount of processing fluid used may be considered. However, this leads to an increase in running costs and places a large environmental burden on society.

Even if the amount of processing fluid used was increased, residual liquid would remain on the inner bottom surface of the pattern, which could cause the pattern to collapse. For this reason, the presence of residual liquid is one of the main causes of reduced product yields.

This invention has been made in consideration of the above problems, and aims to provide a technology that can improve yield while reducing the consumption of processing fluid and mitigating the environmental load in a substrate processing system in which a substrate that has been subjected to wet processing and has an organic solvent applied to its surface is transported from the wet processing device to a supercritical processing device and the substrate is dried using a processing fluid in a supercritical state.

One aspect of the present invention is a substrate processing method for processing a substrate having a pattern-formed surface on which a pattern is formed, comprising: (a) a step of performing, in a wet processing apparatus, a wet processing of the substrate by supplying a chemical liquid to the pattern-formed surface, a rinsing processing by supplying a rinsing liquid to the pattern-formed surface, a replacement processing by supplying an organic solvent to the pattern-formed surface, and a puddle processing for forming a liquid film of the organic solvent in a puddle state on the pattern-formed surface by supplying an organic solvent to the pattern-formed surface, in this order; (b) a step of transporting the substrate from the wet processing apparatus to a supercritical processing apparatus while maintaining the puddle state; and (c) a step of drying the substrate by contacting the puddle-state pattern-formed surface with a processing fluid in a supercritical state in the supercritical processing apparatus, characterized in that in at least one of steps (a), (b), and (c), the inside of the pattern is heated while maintaining the puddle state.

Another aspect of the present invention is a substrate processing system for processing a substrate having a pattern-formed surface on which a pattern is formed, comprising a wet processing apparatus that performs, in the order of wet processing of the substrate by supplying a chemical liquid to the pattern-formed surface, a rinsing process by supplying a rinsing liquid to the pattern-formed surface, a replacement process by supplying an organic solvent to the pattern-formed surface, and a puddle process for forming a liquid film of the organic solvent in a puddle state on the pattern-formed surface by supplying an organic solvent to the pattern-formed surface; a supercritical processing apparatus that dries the substrate by contacting the puddle-state pattern-formed surface with a processing fluid in a supercritical state; and a substrate transport apparatus that transports the substrate from the wet processing apparatus to the supercritical processing apparatus while maintaining the puddle state, and is characterized in that at least one of the wet processing apparatus, the substrate transport apparatus, and the supercritical processing apparatus heats the inside of the pattern while maintaining the puddle state.

In the past, in a wet processing apparatus, after a chemical processing is performed by supplying a chemical solution to a pattern formation surface, a rinsing process, a replacement process, and a liquid puddle process are performed in this order in the conventional technology. As a result, the rinsing solution may remain on the inner bottom surface of the pattern, and this residual liquid is a factor that leads to increased consumption of processing fluid and reduced product yield. Therefore, in the present invention, the inside of the pattern is heated while maintaining the liquid puddle state. This promotes convection diffusion of the liquid components present in the pattern. In other words, the residual liquid present on the inner bottom surface is also convection-diffused into the organic solvent and mixed with the organic solvent. As a result, a drying process is performed using a processing fluid in a supercritical state in a state where there is no residual liquid on the inner bottom surface of the pattern, i.e., in a so-called residual liquid-free state.

As described above, according to the present invention, it is possible to perform supercritical drying processing without leaving any residual liquid. As a result, it is possible to improve yield while reducing the consumption of processing fluid.

1 is a diagram showing a schematic configuration of a first embodiment of a substrate processing system according to the present invention; FIG. 2 is a side view showing the overall configuration of the wet treatment apparatus. 4A and 4B are diagrams for explaining the operation of the wet treatment apparatus. 3A to 3C are diagrams illustrating the configuration and operation of a chuck pin. FIG. 2 is a side view showing the configuration of a supercritical processing apparatus. FIG. 2 is a perspective view showing a structure of a support tray. 1 is a diagram showing an overview of a process executed by a substrate processing system according to a first embodiment; FIG. 2 is a diagram showing pressure changes in a processing chamber. FIG. 13 is a diagram showing an example of the configuration of a wet-type processing apparatus provided in a substrate processing system according to a second embodiment of the present invention. 11 is a diagram showing an outline of a process executed by a substrate processing system according to a second embodiment of the present invention; FIG. FIG. 13 is a diagram showing an example of the configuration of a wet-type processing apparatus provided in a substrate processing system according to a third embodiment of the present invention. FIG. 13 is a diagram showing an overview of a process executed by a substrate processing system according to a third embodiment of the present invention. FIG. 13 is a diagram showing an outline of a process executed by a substrate processing system according to a fourth embodiment of the present invention.

Figure 1 is a diagram showing the schematic configuration of a first embodiment of a substrate processing system according to the present invention. This substrate processing system 1 is a processing system for supplying a processing liquid to the upper surface of various substrates, such as semiconductor wafers, to wet process the substrates and then drying the substrates, and has a system configuration suitable for carrying out the substrate processing method according to the present invention. The substrate processing system 1 mainly comprises a wet processing device 2, a substrate transport device 3, a supercritical processing device 4, and a control device 9.

The wet processing device 2 receives the substrate to be processed and performs a predetermined wet processing. The type of processing is not particularly limited. Wet processing includes development processing using chemicals and cleaning processing for cleaning the substrate, which are performed in the above-mentioned conventional devices, and creates a puddle state in which an organic solvent such as IPA liquid is piled on the pattern-forming surface of the substrate. The substrate transport device 3 transports the substrate from the wet processing device 2 while maintaining the puddle state, and transports it into the supercritical processing device 4. The supercritical processing device 4 performs a drying process (supercritical drying process) on the substrate that has been transported using a processing fluid in a supercritical state. These are installed in a clean room. Therefore, the substrate transport device 3 transports the substrate S in the air atmosphere and under atmospheric pressure.

The control device 9 controls the operation of each of these devices to realize predetermined processing. For this purpose, the control device 9 is equipped with a CPU 91, memory 92, storage 93, and interface 94. The CPU 91 executes various control programs. The memory 92 temporarily stores processing data. The storage 93 stores the control programs executed by the CPU 91. The interface 94 exchanges information with users and external devices. The operation of the devices described below is realized by the CPU 91 executing control programs written in advance in the storage 93 and causing each part of the device to perform a predetermined operation.

When the CPU 91 executes a predetermined control program, the control device 9 realizes functional blocks in software, such as a wet processing control unit 95 that controls the operation of the wet processing device 2, a transport control unit 96 that controls the operation of the substrate transport device 3, and a supercritical processing control unit 97 that controls the operation of the supercritical processing device 4. Note that each of these functional blocks may be configured, at least in part, by dedicated hardware.

As the "substrate" in this embodiment, various substrates such as semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks can be applied. Below, a substrate processing apparatus used primarily for processing disc-shaped semiconductor wafers will be described with reference to the drawings. However, the present invention can be applied to the processing of the various substrates exemplified above in the same manner. Various substrate shapes can also be applied.

In the following explanation, a substrate having a pattern formed on only one of its main surfaces will be used as an example. Here, the side of the main surface on which the pattern is formed will be referred to as the "front surface," and the opposite main surface on which no pattern is formed will be referred to as the "rear surface." The main surface of the substrate facing downward will be referred to as the "lower surface," and the main surface of the substrate facing upward will be referred to as the "upper surface." In the following explanation, the upper surface will be referred to as the front surface.

Figures 2A and 2B are diagrams showing an example of the configuration of a wet processing apparatus installed in a substrate processing system according to a first embodiment of the present invention. More specifically, Figure 2A is a side view showing the overall configuration of the wet processing apparatus, and Figure 2B is a diagram for explaining the operation of the wet processing apparatus. This wet processing apparatus 2 is an apparatus that processes a substrate by supplying a processing liquid to the upper 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.

The wet processing apparatus 2 supplies a processing liquid to the surface (pattern formation surface) Sa of the substrate S, and performs various processes (chemical processing, rinsing processing, replacement processing, liquid film formation processing, etc.) described in detail later. For this purpose, the wet processing apparatus 2 is provided with a substrate holding section 21, a splash guard 22, and processing liquid supply sections 23 and 24 inside the processing chamber 200. The operations of these sections are controlled by a wet processing control section 95 provided in the control device 9. The substrate holding section 21 has a disk-shaped spin chuck 211 having a diameter approximately equal to that of the substrate S, and a number of chuck pins 212 are provided on the periphery of the spin chuck 211.

Figure 3 is a diagram showing the configuration and operation of the chuck pin, where (a) shows the chuck pin in the chucked state (clamped state) and (b) shows the chuck pin in the non-chucked state (open state). Although not shown, in this embodiment, twelve chuck pins 212 are arranged radially around the rotation axis AX of the spin chuck 211. Each chuck pin 212 is arranged on the upper surface of the periphery of the spin chuck 211 so as to be movable in the radial direction D. Here, the "radial direction D" refers to the longitudinal direction of an imaginary line connecting the rotation axis AX and the chuck pin 212.

All of the multiple chuck pins 212 have the same configuration. Therefore, the configuration of one chuck pin 212 will be described below, and the other chuck pins 212 will be given the same reference numerals and their descriptions will be omitted. As shown in FIG. 3, the chuck pin 212 has a chuck abutment surface 212a. This chuck abutment surface 212a is movable along the radial direction D on the upper surface of the peripheral portion of the spin chuck 211. In 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 proceeds in the direction (+D) toward the rotation axis AX. A curved abutment surface 212c is provided above the end of the lower abutment surface 212b in the (-D) direction. This curved abutment surface 212c is finished into a curved surface facing the rotation axis AX. Furthermore, an upper abutment surface 212d extends upward from the upper end of the curved abutment surface 212c. This upper abutment surface 212d is inclined upward as it proceeds in the direction (+D) toward the rotation axis AX. More specifically, as shown in FIG. 3, the curved abutment surface 212c is directly continuous with the upper abutment surface 212d and the lower abutment surface 212b while being disposed between them. Therefore, when the substrate abutment portion 212e, where the upper abutment surface 212d, the curved abutment surface 212c, and the lower abutment surface 212b are connected and abut against the substrate S, is viewed from a horizontal direction perpendicular to the radial direction D, the substrate abutment portion 212e has an approximately C-shape. In other words, the chuck pin 212 is capable of reciprocating along the radial direction D with the substrate abutment portion 212e facing the rotation axis AX.

The chuck pin 212 is connected to the chuck driver 215. The chuck driver 215 moves the chuck pin 212 in the radial direction D in response to a command from the wet processing control unit 95. For example, when transferring the substrate S to and from the substrate transport device 3, as shown in FIG. 3B, the chuck driver 215 moves the chuck pin 212 in the direction (-D) and positions it at the non-chuck position. At this time, the curved contact surface 212c and the upper contact surface 212d are slightly farther away from the rotation axis AX than the radius of the substrate S. On the other hand, the lower contact surface 212b is located below the substrate S. Therefore, as shown in FIG. 3B, the substrate S is supported only by the lower contact surface 212b, and at a position of the lower contact surface 212b that is farther away from the curved contact surface 212c in the (+D) direction.

On the other hand, when chucking the substrate S, as shown in FIG. 3(a), the chuck driver 215 moves the chuck pin 212 in the direction (+D) and positions it at the chuck position. By moving the chuck pin 212 from the non-chuck position to the chuck position in this manner, the support position of the substrate S on the lower abutment surface 212b shifts in the (-D) direction. When the movement of the chuck pin 212 to the chuck position is completed, the substrate S is supported by the lower abutment surface 212b, the curved abutment surface 212c, and the upper abutment surface 212d. In other words, substrate chucking is completed.

When releasing the chuck of the substrate S, the chuck pin 212 moves in the reverse order to that described above, and the support position of the substrate S on the lower contact surface 212b shifts in the (+D) direction.

In addition, as the support position of the substrate S on the lower contact surface 212b moves in the radial direction D, the height position of the substrate S in the vertical direction Z is displaced by a distance dz. Therefore, when the wet processing control unit 95 issues a reciprocating movement command to the chuck driving unit 215, the chuck pin 212 moves reciprocatingly in the radial direction D, and the substrate S is repeatedly raised and lowered in synchronization with the movement. In other words, it is possible to impart vertical vibrations to the substrate S. Note that, although the present embodiment uses the chuck pin 212 capable of imparting vibration, a conventional chuck pin that does not have a vibration imparting function may also be used.

Returning to Figures 2A and 2B, we will continue to explain the configuration of the wet processing apparatus 2. The spin chuck 211 is supported by a rotation support shaft 213 extending downward from the center of its bottom surface so that its upper surface is horizontal. The rotation support shaft 213 is rotatably supported by a rotation mechanism 214 attached to the bottom of the processing chamber 200. The rotation mechanism 214 has a built-in rotation motor (not shown), and when the rotation motor rotates in response to a control command from the control device 9, the spin chuck 211 directly connected to the rotation support shaft 213 rotates around the rotation axis AX shown by the dashed line. In Figure 2, the up-down direction is the vertical direction. As a result, the substrate S is rotated around the rotation axis AX while remaining in a horizontal position.

The splash guard 22 is provided so as to surround the substrate holding part 21 from the side. The splash guard 22 has a roughly cylindrical cup 221 provided so as to cover the peripheral part of the spin chuck 211, and a liquid receiving part 222 provided below the outer periphery of the cup 221. The cup 221 moves up and down in response to a control command from the control device 9. The cup 221 moves up and down between a lower position where the upper end of the cup 221 is lowered below the peripheral part of the substrate S held by the spin chuck 211 as shown in FIG. 2A, and an upper position where the upper end of the cup 221 is located above the peripheral part of the substrate S as shown in FIG. 2B.

When the cup 221 is in the lower position, as shown in FIG. 2A, the substrate S held by the spin chuck 211 is exposed outside the cup 221. This prevents the cup 221 from becoming an obstacle, for example, when the substrate S is loaded into or unloaded from the spin chuck 211.

When the cup 221 is in the upper position, as shown in FIG. 2B, it surrounds the peripheral portion of the substrate S held by the spin chuck 211. This prevents the processing liquid shaken off from the peripheral portion of the substrate S during liquid supply, which will be described later, from scattering inside the chamber 200, and makes it possible to reliably collect the processing liquid. That is, as the substrate S rotates, droplets of the processing liquid shaken off from the peripheral portion of the substrate S adhere to the inner wall of the cup 221 and flow downward, and are collected by the liquid receiving portion 222 arranged below the cup 221. Multiple stages of cups may be provided concentrically to collect multiple processing liquids individually.

The processing liquid supply unit 23 has a structure in which a nozzle 234 is attached to the tip of an arm 233 that extends horizontally from a pivot shaft 232 that is rotatably mounted on a base 231 fixed to the processing chamber 200. The arm 233 swings as the pivot shaft 232 rotates in response to a control command from the control device 9, and the nozzle 234 at the tip of the arm 233 moves between a retracted position retracted to the side from above the substrate S as shown in FIG. 2A, and a processing position above the substrate S as shown in FIG. 2B.

The nozzle 234 is connected to a processing liquid supply source 238, and when an appropriate processing liquid is sent from the processing liquid supply source 238, the processing liquid is discharged from the nozzle 234 toward the substrate S. As shown in FIG. 2B, the spin chuck 211 rotates at a relatively low speed to rotate the substrate S, and the processing liquid F1 is supplied from the nozzle 234 positioned above the center of rotation of the substrate S, so that the surface Sa of the substrate S is processed with the processing liquid L1. In this embodiment, a chemical liquid (developer, etching liquid, cleaning liquid, etc.) and a rinsing liquid are used as the processing liquid L1, so the processing liquid supply source 238 has a chemical liquid supply source 238A and a DIW supply source 238B. In addition, a heater 239 is inserted in the piping connecting the DIW supply source 238B and the nozzle 234. The heater 239 heats room temperature DIW (deionized water) that functions as a rinsing liquid supplied from the DIW supply source 238B in response to a heating command from the wet processing control unit 95, and generates DIW at a temperature higher than room temperature (hereinafter referred to as "high temperature DIW"). In this specification, "room temperature" means a temperature range of 5°C to 35°C. The temperature of the high temperature DIW will be explained later.

The other processing liquid supply unit 24 also has a configuration corresponding to the first processing liquid supply unit 23 described above. That is, the second processing liquid supply unit 24 has a base 241, a pivot shaft 242, an arm 243, a nozzle 244, etc., and these configurations are equivalent to those corresponding to the first processing liquid supply unit 23. The pivot shaft 242 rotates in response to a control command from the control device 9, causing the arm 243 to swing. The nozzle 244 at the tip of the arm 243 supplies processing liquid to the surface Sa of the substrate S.

In this embodiment, the second processing liquid supply unit 24 is used for the purpose of carrying out the replacement process and the liquid film formation process. That is, after the wet processing, the substrate S is transported to the supercritical processing device 4 and subjected to the supercritical drying process, but in order to prevent the surface of the substrate S from being exposed and oxidized during transportation or the fine pattern formed on the surface from collapsing, the substrate S is transported with its surface covered with a paddle-shaped liquid film.

As the liquid that constitutes the liquid film, an organic solvent such as isopropyl alcohol (IPA) or acetone is used, which has a lower surface tension than water, which is the main component of the processing liquid used in the chemical processing and rinsing processes. These organic solvents are supplied from an organic solvent supply source 248.

Here, two sets of processing liquid supply units are provided in the wet processing apparatus 2, but the number of processing liquid supply units installed and their structures and functions are not limited to this. For example, there may be only one set of processing liquid supply units, or three or more sets. Also, one processing liquid supply unit may have multiple nozzles. For example, multiple nozzles may be provided at the tip of one arm. Also, in addition to the above-mentioned mode in which the nozzle is positioned at a predetermined position and ejects the processing liquid, for example, the nozzle may eject the processing liquid while scanning and moving along the surface Sa of the substrate S.

Returning to FIG. 1, the explanation will continue. The substrate transport device 3 is provided with a transport robot 30 having a hand 31 attached to the tip of a retractable and rotatable arm. The hand 31 can support the substrate by partially abutting against the underside of the substrate, and can move forward and backward relative to both the wet processing device 2 and the supercritical processing device 4, as shown by the dotted line in FIG. 1. This allows the substrate to be loaded and unloaded from both the wet processing device 2 and the supercritical processing device 4. The operation 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, and these can be appropriately selected and used in this embodiment, so a detailed explanation will be omitted.

Figure 4 is a side view showing the configuration of a supercritical processing apparatus. The supercritical processing apparatus 4 is an apparatus that performs a drying process using a processing fluid in a supercritical state on a substrate S after wet processing. More specifically, the supercritical processing apparatus 4 is an apparatus that receives the substrate S after wet processing, replaces the liquid remaining on the substrate S with a processing fluid in a supercritical state, and then discharges the processing fluid, ultimately bringing the substrate S to a dry state.

The supercritical processing apparatus 4 comprises a processing unit 41, a transfer unit 43, and a supply unit 45. The processing unit 41 is the main entity that carries out the supercritical drying process. The transfer unit 43 receives the substrate S after wet processing transported by the substrate transport device 3 and transports it into the processing unit 41, and also transfers the processed substrate S from the processing unit 41 to an external transport device. The supply unit 45 supplies the chemicals, power, energy, etc. required for processing to the processing unit 41 and the transfer unit 43. These operations are controlled by the control device 9, in particular the supercritical processing control unit 97.

The processing unit 41 has a structure in which a processing chamber 412 is attached on a base 411. The processing chamber 412 is constructed by combining several metal blocks, and its interior is hollow, forming a processing space SP. The substrate S to be processed is loaded into the processing space SP and processed. A slit-shaped opening 421 that is elongated and extends in the X direction is formed on the (-Y) side surface of the processing chamber 412. The processing space SP communicates with the outside space via the opening 421. The cross-sectional shape of the processing space SP is roughly the same as the opening shape of the opening 421. In other words, 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 cavity that extends in the Y direction.

A lid member 413 is provided on the (-Y) side of the processing chamber 412 so as to close the opening 421. The lid member 413 closes the opening 421 of the processing chamber 412, thereby forming an airtight processing container. This makes it possible to process the substrate S under high pressure in the internal processing space SP. A flat support tray 415 is attached in a horizontal position to the (+Y) side of the lid member 413. The upper surface of the support tray 415 serves as a support surface on which the substrate S can be placed. The lid member 413 is supported by a support mechanism (not shown) so as to be freely movable horizontally in the Y direction.

The lid member 413 can be moved forward and backward relative to the processing chamber 412 by a forward and backward mechanism 453 provided in the supply unit 45. Specifically, the forward and backward mechanism 453 has a linear motion mechanism such as a linear motor, a linear guide, a ball screw mechanism, a solenoid, or an air cylinder. Such a linear motion mechanism moves the lid member 413 in the Y direction. The forward and backward mechanism 453 operates in response to a control command from the control device 9.

When the lid member 413 moves in the (-Y) direction to move away from the processing chamber 412 and the support tray 415 is pulled out from the processing space SP through the opening 421 as shown by the dotted line, access to the support tray 415 becomes possible. That is, it becomes possible to place a substrate S on the support tray 415 and to remove the substrate S placed on the support tray 415. On the other hand, when the lid member 413 moves in the (+Y) direction, the support tray 415 is accommodated in the processing space SP. When a substrate S is placed on the support tray 415, the substrate S is transported into the processing space SP together with the support tray 415.

Figure 5 is a perspective view showing the structure of the support tray. The support tray 415 has a tray member 416 and a number of support pins 417. The tray member 416 has a structure in which a depression 418 having a diameter corresponding to the planar size of the substrate S, more specifically, a diameter slightly larger than the diameter of the circular substrate S, is provided on the horizontal and flat upper surface of the plate-like structure, for example.

The recess 418 partially extends to the side of the tray member 416. In other words, the side wall surface of the recess 418 is not circular, but is partially cut out. Therefore, in this cutout portion, part of the bottom surface 418a of the recess 418 is directly connected to the side surface. In this example, such cutout portions are provided at both ends on the X side and the (+Y) end of the support tray 415, and in these locations, the bottom surface 418a is directly connected to the side surface.

In addition, through holes 419 for inserting the lift pins 437 are drilled in the bottom surface 418a at positions corresponding to the lift pins 437 of the transfer unit 43. The lift pins 437 are raised and lowered through the through holes 419, thereby realizing a state in which the substrate S is housed in the recess 418 and a state in which it is lifted above this.

A number of support pins 417 are arranged on the periphery of the recess 418. The number of support pins 417 can be any number, but it is preferable that there be three or more in order to stably support the substrate S. In this embodiment, three support pins 417 are attached to the tray member 416 so as to surround the bottom surface 418a when viewed from above in a plan view. As shown in the partially enlarged view in Figure 5, the support pin 417 has a height restriction portion 417a and a horizontal position restriction portion 417b.

The height restriction portion 417a has a flat upper surface and abuts against the peripheral edge of the lower surface of the substrate S, thereby supporting the substrate S and restricting its position in the vertical direction Z (hereinafter referred to as the "height position"). On the other hand, the horizontal position restriction portion 417b extends above the upper end of the height restriction portion 417a and abuts against the side surface of the substrate S, thereby restricting the position of the substrate S in the horizontal direction (XY direction). By means of such support pins 417, the substrate S is supported in a horizontal position facing the bottom surface 418a of the recess 418 and spaced above the bottom surface 418a.

The lid member 413 moves in the (+Y) direction to close the opening 421, thereby sealing the processing space SP. A seal member 422 is provided between the (+Y) side surface of the lid member 413 and the (-Y) side surface of the processing chamber 412, and keeps the processing space SP airtight. The seal member 422 is made of rubber, for example. The lid member 413 is fixed to the processing chamber 412 by a locking mechanism (not shown). Thus, in this embodiment, the lid member 413 can be switched between a closed state (solid line) in which the opening 421 is closed to seal the processing space SP, and a separated state (dotted line) in which the lid member 413 is significantly separated from the opening 421 to allow the substrate S to be inserted and removed.

With the processing space SP kept airtight, processing of the substrate S is performed in the processing space SP. In this embodiment, the fluid supply section 457 provided in the supply unit 45 delivers a processing fluid of a substance that can be used in supercritical processing, such as carbon dioxide, as the processing fluid, and the processing fluid is pressurized in the processing chamber 412 to bring it to a supercritical state. The processing fluid is supplied to the processing unit 41 in a gaseous or liquid state. Carbon dioxide is a chemical substance suitable for supercritical drying processing because it reaches a supercritical state at a relatively low temperature and pressure and has the property of dissolving organic solvents that are often used in substrate processing. The critical point at which carbon dioxide reaches a supercritical state is an atmospheric pressure (critical pressure) of 7.38 MPa and a temperature (critical temperature) of 31.1°C.

When the processing space SP is filled with the processing fluid and the processing space SP reaches an appropriate temperature and pressure, the processing space SP is filled with the processing fluid in a supercritical state. In this way, the substrate S is processed by the processing fluid in a supercritical state in the processing chamber 412. The supply unit 45 is provided with a fluid recovery section 455, and the fluid after processing is recovered by the fluid recovery section 455. The fluid supply section 457 and the fluid recovery section 455 are controlled by the supercritical processing control section 97.

The processing space SP has a shape and volume capable of receiving the support tray 415 and the substrate S supported thereon. That is, the processing space SP has a roughly rectangular cross-sectional shape that is wider than the width of the support tray 415 in the horizontal direction and greater than the combined height of the support tray 415 and the substrate S in the vertical direction, and a depth capable of receiving the support tray 415. In this way, the processing space SP has a shape and volume sufficient to receive the support tray 415 and the substrate S. However, there is only a small gap between the support tray 415 and the substrate S and the inner wall surface of the processing space SP. Therefore, a relatively small amount of processing fluid is required to fill the processing space SP.

The fluid supply unit 457 supplies processing fluid to the processing space SP further (+Y) side than the (+Y) end of the substrate S. Meanwhile, the fluid recovery unit 55 discharges processing fluid flowing through the space above the substrate S and the space below the support tray 415 in the processing space SP further (-Y) side than the (-Y) end of the substrate S. As a result, laminar flows of processing fluid are formed in the processing space SP from the (+Y) side toward the (-Y) side above the substrate S and below the support tray 415, respectively.

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 results of a detection unit (not shown), and controls the fluid supply unit 457 and the fluid recovery unit 455 based on the results. This appropriately manages the supply of processing fluid to the processing space SP and the discharge of processing fluid from the processing space SP, and adjusts the pressure and temperature in the processing space SP according to a predetermined processing recipe.

The transfer unit 43 is responsible for transferring the substrate S between the substrate transport device 3 and the support tray 415. For this purpose, the transfer unit 43 includes a main body 431, a lifting member 433, a base member 435, and a plurality of lift pins 437. The lifting member 433 is a columnar member extending in the Z direction, and is supported by a support mechanism (not shown) so as to be movable in the Z direction relative to the main body 431. A base member 435 having a substantially horizontal upper surface is attached to the upper portion of the lifting member 433. A plurality of lift pins 437 are erected upward from the upper surface of the base member 435. Each of the lift pins 437 supports the substrate S in a horizontal position from below by abutting its upper end against the lower surface of the substrate S. In order to stably support the substrate S in a horizontal position, it is desirable to provide three or more lift pins 437 whose upper ends have the same height.

The lifting member 433 can be raised and lowered by a lifting mechanism 451 provided in the supply unit 45. Specifically, the lifting mechanism 451 has a linear motion mechanism such as a linear motor, a linear guide, a ball screw mechanism, a solenoid, an air cylinder, etc., and such a linear motion mechanism moves the lifting member 433 in the Z direction. The lifting mechanism 451 operates in response to a control command from the control device 9.

The base member 435 moves up and down as the lifting member 433 moves up and down, and the multiple lift pins 437 move up and down integrally with the base member 435. This allows the transfer of the substrate S between the transfer unit 43 and the support tray 415. More specifically, as shown by the dotted line in FIG. 5, the substrate S is transferred in a state in which the support tray 415 is pulled out of the chamber. For this purpose, the support tray 415 is provided with a through hole 419 for inserting the lift pin 437. When the base member 435 rises, the upper end of the lift pin 437 reaches a position higher than the upper surface of the support tray 415 through the through hole 419. In this state, the substrate S transferred by the transport robot 30 is transferred from the hand 31 of the transport robot 30 to the lift pin 437. When the lift pin 437 descends, the substrate S is transferred from the lift pin 437 to the support tray 415. The substrate S can be removed by the reverse procedure to the above.

Figure 6 is a diagram showing an overview of the processing performed by the substrate processing system according to the first embodiment. This substrate processing system 1 receives a substrate S to be processed, and sequentially performs wet processing using processing liquids such as chemicals, rinse liquids, and organic solvents, a transport process for transporting the wet-processed substrate S from the wet processing device 2 to the supercritical processing device 4, and a supercritical drying process using a supercritical processing fluid. Specifically, when the substrate S to be processed is received in the wet processing device 2 constituting the substrate processing system 1 (step S10), wet processing (step S20), transport processing (step S30), and supercritical drying processing (step S40) are performed in this order.

Here, the substrate S may be transported directly by an external transport device, or may be transported from the external transport device via a transport robot 30.

The wet processing apparatus 2 performs wet processing on the substrate S using a predetermined processing liquid (step S20). As with the conventional apparatus, this embodiment performs chemical processing (step S21), rinsing processing (step S22), replacement processing (step S23), and liquid film formation processing (step S24) in this order, but differs from the conventional apparatus in the following respects. That is, in the wet processing, after a predetermined chemical processing is performed by supplying a chemical liquid such as a developer or cleaning liquid in step S21, high-temperature DIW is supplied to the surface Sa of the substrate S as a rinsing liquid (step S22). Subsequently, an organic solvent such as IPA is supplied to the substrate S, so that the rinsing liquid adhering to the surface Sa of the substrate S is replaced by the organic solvent (step S23), and a liquid mound state in which the organic solvent is piled is created. That is, a liquid film LF is formed on the surface Sa of the substrate S (step S24: liquid film formation processing).

As described above, as in the conventional apparatus, the chemical liquid processing (step S21), rinsing processing (step S22), replacement processing (step S23), and liquid film forming processing (step S24) are performed in this order, so that DIW may remain as residual liquid on the inner bottom surface of the pattern PT formed on the surface Sa of the substrate S, as shown in the upper right part of the figure. However, in this embodiment, high-temperature DIW is used as the rinsing liquid, so the inside of the pattern PT is heated by the high-temperature DIW. This promotes convection diffusion of liquid components such as DIW and IPA present in the pattern PT. In other words, the residual liquid present on the inner bottom surface is also convected and diffused into the IPA and mixed with the IPA. In this way, a residual liquid-free liquid film LF is formed on the surface Sa of the substrate S.

Here, in order to promote convection diffusion, it is desirable to set the temperature of the high-temperature DIW to 40 ° C. or higher, and may be set to, for example, higher than the boiling point of IPA (82.4° C.). However, due to the high temperature setting of the DIW, splashing may occur when the liquid film is formed. This splashing may make it difficult to maintain the liquid film LF. Therefore, it is preferable to obtain the upper limit temperature of the high-temperature DIW at which the liquid film LF can be maintained using, for example, a monitoring technique described in Japanese Patent No. 7179568, a so-called dispense monitor. Therefore, in this embodiment, the wet processing control unit 95 controls the heater 239 so that the temperature of the high-temperature DIW is 40 ° C. or higher and the upper limit temperature or lower. As a result, the residual liquid can be removed while maintaining the liquid puddle state. The method of setting the upper limit temperature is the same in the embodiments described later.

The substrate S that has undergone wet processing is transported from the wet processing device 2 to the supercritical processing device 4 by the substrate transport device 3 while still in a puddle state (step S30).

The substrate S transported to the supercritical processing device 4 is accommodated in the processing chamber 412 in a liquid-filled state. Specifically, the substrate S is transported with the pattern-formed surface (surface Sa) facing up, and the pattern-formed surface is covered with a thin liquid film LF. As shown by the dotted line in FIG. 4, the lift pins 437 rise with the lid member 413 moving to the (-Y) side and the support tray 415 pulled out. The transport device transfers the substrate S to the lift pins 437. The lift pins 437 descend, so that the substrate S is placed on the support tray 415. When the support tray 415 and the lid member 413 move together in the (+Y) direction, 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 lid member 413.

In this state, carbon dioxide as a processing fluid is introduced in a gas phase into the processing space SP (step S41). When the substrate S is loaded, outside air enters the processing space SP, but this can be replaced by introducing the gas phase processing fluid. Furthermore, the pressure inside the processing chamber 412 increases as the gas phase processing fluid is injected.

In addition, during the process of introducing the processing fluid, the processing fluid is continuously discharged from the processing space SP. That is, even while the processing fluid is being introduced by the fluid supply unit 457, the fluid recovery unit 455 is discharging the processing fluid from the processing space SP. This allows the processing fluid used for processing to be discharged without remaining in the processing space SP, and prevents impurities such as residues that have been taken in the processing fluid from re-adhering to the substrate S.

If the amount of processing fluid supplied is greater than the amount of processing fluid discharged, the density of the processing fluid in the processing space SP increases, and the pressure inside the chamber increases. Conversely, if the amount of processing fluid supplied is less than the amount of processing fluid discharged, the density of the processing fluid in the processing space SP decreases, and the pressure inside the chamber is reduced. The supply of such processing fluid to the processing chamber 412 and the discharge of the processing fluid from the processing chamber 12 are performed based on a supply and discharge recipe created in advance. In other words, the control device 9 controls the fluid supply unit 457 and the fluid recovery unit 455 based on the supply and discharge recipe, thereby adjusting the supply and discharge timing and the flow rate of the processing fluid.

Figure 7 shows the pressure change inside the processing chamber. When the processing fluid is carbon dioxide, its critical temperature is not very different from room temperature, so the temperature change during processing is not very large. Here, the phenomenon will be explained by focusing on the pressure inside the chamber, where the change is more noticeable. When the processing space SP is open to the atmosphere and the internal pressure is atmospheric pressure Pa, the introduction of the processing fluid begins at time T1 after the processing space SP is sealed, and the internal pressure begins to rise.

Pressurization continues until the pressure of the processing fluid in the processing space SP rises and exceeds the critical pressure Pc (step S42). At time T2 when the chamber reaches the critical pressure Pc, the processing fluid becomes supercritical in the chamber. That is, due to a phase change in the processing space SP, the processing fluid transitions from the gas phase to the supercritical state. When the processing space SP is filled with the processing fluid in the supercritical state, the IPA (or a mixed fluid of IPA and DIW) covering the substrate S is replaced by the processing fluid in the supercritical state. IPA and the like that are liberated from the surface of the substrate S are discharged from the processing chamber 412 together with the processing fluid in a dissolved state 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 a mixed fluid of IPA and DIW) adhering to the substrate S as the liquid to be replaced, and discharging it out of the processing chamber 412.

After time T3 when the processing fluid has definitely transitioned to the supercritical state, the processing space SP is kept filled with the processing fluid in the supercritical state for a predetermined time (steps S43, S44), so that the liquid to be replaced adhering to the substrate S can be completely replaced and discharged outside the chamber. Note that while FIG. 7 shows the pressure Pm inside the chamber in the supercritical state as constant, the pressure may fluctuate as long as it does not fall below the critical pressure Pc.

At time T4, when the replacement of the liquid to be replaced with the supercritical processing fluid in the processing chamber 412 is completed ("YES" in step S44), the processing fluid in the processing space SP is discharged to dry the substrate S. Specifically, the amount of fluid discharged from the processing space SP is increased to reduce the pressure in the processing chamber 12 filled with the supercritical processing fluid (step S45).

In the depressurization process, the supply of the processing fluid may be stopped, or a small amount of processing fluid may be continuously supplied. When the processing space SP is depressurized from a state filled with processing fluid in a supercritical state, the processing fluid changes phase from the supercritical state to a gas phase. By discharging the vaporized processing fluid to the outside, the substrate S becomes dry. At this time, the depressurization speed is adjusted so that a solid phase and a liquid phase are not generated due to a sudden drop in temperature. That is, after the depressurization starts at time T4, the depressurization is performed at a relatively low depressurization speed until time T5 when the pressure falls reliably below 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.

After time T5 when the processing fluid is completely vaporized, the depressurization speed is increased, which allows the pressure to be reduced to atmospheric pressure Pa in a short time. In this way, the processing fluid does not liquefy during the entire period from time T4 when depressurization begins to time T6 when the pressure inside the chamber drops to atmospheric pressure Pa, and the formation of a gas-liquid interface on the substrate S with its surface exposed after drying is avoided.

In this way, in the supercritical drying process of this embodiment, the processing space SP is filled with a processing fluid in a supercritical state, and then the liquid is changed into a gas phase and discharged, thereby efficiently replacing the liquid adhering to the substrate S and preventing it from remaining on the substrate S. Furthermore, the substrate can be dried while avoiding problems caused by the formation of a gas-liquid interface, such as contamination of the substrate due to the adhesion of impurities and pattern collapse.

After processing, the substrate S is discharged to the next process (step S50). That is, the cover member 413 moves in the (-Y) direction, and the support tray 415 is pulled out from the processing chamber 412 to the outside, and the substrate S is transferred to an external transport device via the transfer unit 43. At this time, the substrate S is in a dry state. The content of the next process is optional. In this way, the processing of one substrate S is completed. If there is another substrate to be processed, the process returns to step S101, a new substrate S is received, and the above processing is repeated.

As described above, according to the first embodiment, the wet processing apparatus 2 uses high-temperature DIW for rinsing, so the inside of the pattern PT is heated by the high-temperature DIW. Therefore, even if DIW remains in the pattern PT on the pattern formation surface (surface Sa) of the substrate S in a puddle state, the DIW (residual liquid) is effectively convected and diffused into the IPA and mixed into the IPA. Therefore, the drying process is performed using a processing fluid in a supercritical state without residual liquid. This means that the supercritical drying process is performed with high quality without using an excessive amount of processing fluid in a supercritical state. As a result, the yield can be improved while reducing the consumption of processing fluid.

As described above, in the first embodiment, DIW corresponds to an example of the "rinsing liquid" of the present invention. Also, IPA corresponds to an example of the "organic solvent" of the present invention. The surface Sa of the substrate S corresponds to the "pattern formation surface" of the present invention. Also, the liquid film formation process corresponds to an example of the "liquid puddle process" of the present invention. Also, steps S20, S30, and S40 correspond to examples of "step (a)", "step (b)", and "step (c)" of the present invention, respectively.

In the above first embodiment, high-temperature DIW is used as a means for heating the inside of the pattern PT, but other means may also be used.

Figure 8 is a diagram showing an example of the configuration of a wet processing apparatus installed in a substrate processing system according to a second embodiment of the present invention. This substrate processing system 1 differs significantly from the first embodiment in that, instead of being configured to supply room temperature DIW as a rinsing liquid, a backside heating unit 25 is provided that ejects high-temperature DIW toward the center of the backside Sb of the substrate S to heat it. Below, the second embodiment will be described, focusing on the differences from the first embodiment, and the same configurations and operations will be denoted by the same or corresponding reference numerals and will not be described again.

The rear surface heating unit 25 has a lower nozzle 251. As shown in FIG. 8, the lower nozzle 251 has a single outlet 252 facing the center of the rear surface Sb of the substrate S held by the spin chuck 211. The outlet 252 outlets high-temperature DIW vertically upward. The outlet high-temperature DIW is incident almost perpendicularly on the center of the rear surface Sb of the substrate S held by the spin chuck 211. A lower surface supply pipe 253 is connected to the lower nozzle 251. The lower surface supply pipe 253 is inserted into the inside of the vertical hollow portion provided in the rotating support shaft 213 and the rotating mechanism 214. A DIW supply source 254 is connected to the lower surface supply pipe 253. A heater 255 is inserted in the pipe that interconnects the lower surface supply pipe 253 and the DIW supply source 254. This heater 255 heats the room temperature DIW supplied from the DIW supply source 254 in response to a heating command from the wet process control unit 95 to generate high-temperature DIW.

9 is a diagram showing an overview of the processing performed by the substrate processing system according to the second embodiment of the present invention. As in the first embodiment, the substrate processing system 1 receives the substrate S to be processed, and sequentially performs wet processing using processing liquids such as chemicals, rinse liquids, and organic solvents, a transport process for transporting the wet-processed substrate S from the wet processing device 2 to the supercritical processing device 4, and a supercritical drying process using a supercritical processing fluid. In the second embodiment, after a predetermined chemical processing is performed by supplying a chemical liquid such as a developer or cleaning liquid in step S21, DIW at room temperature is supplied to the surface Sa of the substrate S as a rinse liquid (step S22A). Subsequently, an organic solvent such as IPA is supplied to the substrate S, so that the rinse liquid adhering to the surface Sa of the substrate S is replaced with the organic solvent (step S23), and a liquid mound state in which the organic solvent is piled is created. That is, a liquid film LF is formed on the surface Sa of the substrate S (liquid film formation process). In parallel with this liquid film formation process, high-temperature DIW is discharged from the outlet 252 of the lower nozzle 251. This high-temperature DIW is incident on the center of the back surface Sb of the substrate S almost perpendicularly and is supplied to the entire back surface Sb. The supply of this high-temperature DIW to the substrate S heats the inside of the pattern PT. Therefore, as in the first embodiment, convection diffusion of liquid components such as DIW and IPA present in the pattern PT is promoted. In other words, the residual liquid present on the inner bottom surface is also convected and diffused into the IPA and mixed with the IPA. In this way, a residual liquid-free liquid film LF is formed on the front surface Sa of the substrate S (step S24A).

The substrate S that has been subjected to the wet processing is transported by the substrate transport device 3 from the wet processing device 2 to the supercritical processing device 4 while still in a puddle state (step S30). Then, in the same manner as in the first embodiment, the supercritical drying process (step S40) is performed in the supercritical processing device 4.

Thus, the same effect as in the first embodiment can be obtained. In this way, in the second embodiment, high-temperature DIW is used to heat the substrate S from the lower surface side, but a fluid other than DIW may be heated and the heating fluid may be supplied to the rear surface Sb of the substrate S. In this way, the temperature of the high-temperature DIW and the heating fluid (collectively referred to as the "heating medium") must be 80 °C or higher in order to heat the inside of the pattern PT. On the other hand, as for the upper limit temperature, it is preferable to use a dispense monitor to find the upper limit temperature of the heating medium at which the liquid film LF can be maintained, as in the first embodiment.

In the second embodiment described above, the heating of the substrate S by the heating medium corresponds to an example of the "first heating process" of the present invention.

Figure 10 is a diagram showing an example of the configuration of a wet processing apparatus installed in a substrate processing system according to a third embodiment of the present invention. This substrate processing system 1 differs significantly from the first embodiment in that, instead of being configured to supply room temperature DIW as a rinsing liquid, a heater 26 is built into the spin chuck 211. Below, the third embodiment will be described, focusing on the differences from the first embodiment, and the same configurations and operations will be denoted by the same or equivalent reference numerals and will not be described again.

The heater 26 is disposed on the spin chuck 211 so that its upper surface faces the entire back surface Sb of the substrate S held by the spin chuck 211. The heater 26 is electrically connected to the wet processing control unit 95. The heater 26 is activated when power is supplied from the wet processing control unit 95. This causes the substrate S to be uniformly heated by conductive heat and radiant heat from the upper surface of the spin chuck 211. As a result, the inside of the pattern PT is heated.

11 is a diagram showing an outline of the processing performed by the substrate processing system according to the third embodiment of the present invention. As in the first embodiment, the substrate processing system 1 receives the substrate S to be processed, and sequentially performs wet processing using processing liquids such as chemicals, rinse liquids, and organic solvents, a transport process for transporting the wet-processed substrate S from the wet processing device 2 to the supercritical processing device 4, and a supercritical drying process using a supercritical processing fluid. In the third embodiment, after a predetermined chemical processing is performed by supplying chemicals such as a developer and a cleaning liquid in step S21, DIW at room temperature is supplied to the surface Sa of the substrate S as a rinse liquid (step S22A). Subsequently, an organic solvent such as IPA is supplied to the substrate S, so that the rinse liquid adhering to the surface Sa of the substrate S is replaced with the organic solvent (step S23), and a liquid mound state in which the organic solvent is piled is created. That is, a liquid film LF is formed on the surface Sa of the substrate S (liquid film forming process). In parallel with this liquid film forming process, the heater 26 is operated to heat the substrate S from below. This heats the inside of the pattern PT. Therefore, as in the first embodiment, convection diffusion of liquid components such as DIW and IPA present in the pattern PT is promoted. In other words, the residual liquid present on the inner bottom surface also convects and diffuses into the IPA, and is mixed into the IPA. In this way, a residual liquid-free liquid film LF is formed on the surface Sa of the substrate S (step S24B).

The substrate S that has been subjected to the wet processing is transported by the substrate transport device 3 from the wet processing device 2 to the supercritical processing device 4 while still in a puddle state (step S30). Then, in the same manner as in the first embodiment, the supercritical drying process (step S40) is performed in the supercritical processing device 4.

Therefore, the same effect as in the first embodiment can be obtained. In this way, in the third embodiment, the substrate S is heated by the heater 26 disposed below and away from the substrate S, which corresponds to an example of the "second heating process" of the present invention. Of course, the second heating process may be performed with the heater facing and in close contact with the back surface Sb of the substrate S.

In the above first to third embodiments, the inside of the pattern PT is heated in the wet treatment device 2, but the inside of the pattern PT of the substrate S may be heated while the substrate is being transported to the supercritical treatment device 4 by the substrate transport device 3 (step S30). For example, the hand 31 of the transport robot 30 may be configured to have a built-in heater (not shown), and the inside of the pattern PT may be heated by heating the substrate S with the heater (fourth embodiment).

The supercritical processing apparatus 4 may also be configured to heat the inside of the pattern PT of the substrate S supported on the tray member 416 before the processing fluid is brought into contact with the substrate S. For example, the tray member 416 of the supercritical processing apparatus 4 may be configured to have a built-in heater (not shown), and the inside of the pattern PT may be heated by heating the substrate S with the heater (fifth embodiment).

In the first to fifth embodiments, the chuck pins 212 have a vibration function in addition to the function of clamping the side edges of the substrate S to hold the substrate S. Therefore, a step of imparting vibration to the substrate S may be added to each of the first to fifth embodiments after the liquid film formation process (steps S24, S24A, S24B) and before the substrate transport (step S30). Here, a fourth embodiment in which a configuration for imparting vibration is added to the first embodiment will be described with reference to FIG. 12. The same applies to the other second to fifth embodiments.

Figure 12 is a diagram showing an overview of the process executed by the substrate processing system according to the fourth embodiment of the present invention. In the fourth embodiment, after a liquid puddle state is created in the wet processing device 2, the wet processing control unit 95 gives a reciprocating movement command to the chuck driving unit 215. Then, the chuck state shown in Figure 3 (a) and the non-chuck state shown in Figure 3 (b) are alternately repeated. That is, the substrate S is repeatedly raised and lowered with the reciprocating movement of the chuck pin 212 in the radial direction D. As a result, as shown in the lower left diagram of Figure 12, vibration is applied to the substrate S in the vertical direction Z, and the DIW and IPA are advected and diffused. In this way, the residual liquid (DIW) disappears in a shorter time than in the first embodiment, and the DIW spreads over the entire liquid film LF (step S60). In this specification, the process of removing the residual liquid by adding vibration in this way is called a "residual liquid removal process".

In addition, in the fourth embodiment, a vibration function is essential to perform the residual liquid removal process, but this function is performed by the chuck pin 212. Therefore, there is no need to add a component that specializes in performing the vibration function, which reduces the cost of the device.

In addition, in the fourth embodiment, the substrate S is vibrated in the vertical direction Z to perform the residual liquid removal process, but the manner in which the vibration is applied is not limited to this. For example, while the substrate S is held by the chuck pins 212, the wet process control unit 95 may issue a forward/reverse rotation command to the rotation mechanism 214. In this case, upon receiving the forward/reverse rotation command, the rotation mechanism 214 repeats an operation of rotating the substrate S forward and reverse by a predetermined angle around the rotation axis AX, that is, a rotation operation. In this way, vibration may be applied to the substrate S by rotating the substrate S in the circumferential direction.

In addition, vibration may be applied to the substrate S by a separately added configuration without applying vibration along the vertical direction Z by the chuck pin 212 (hereinafter referred to as "applying vertical vibration") or vibration along the circumferential direction by the rotation mechanism 214 (hereinafter referred to as "applying rotational vibration"). For example, following the liquid film formation process (step S24), the wet process control unit 95 may operate an ultrasonic vibrator installed at a position away from the substrate holding unit 21 to vibrate the substrate S with ultrasonic waves generated by the ultrasonic vibrator. Alternatively, the vibrator may be attached to the substrate holding unit 21 in advance, and the wet process control unit 95 may operate the vibrator following the liquid film formation process (step S24). In these embodiments, the vibration direction of the substrate S can be controlled by the installation mode of the vibrator. Note that the vibrator and ultrasonic vibrator may be conventionally known. Therefore, detailed configuration explanations are omitted in this specification.

In the fourth embodiment, the substrate S in a puddle state is subjected to vibration in the wet processing apparatus 2, but vibration may be applied in the substrate transport apparatus 3 or the supercritical processing apparatus 4. For example, in the first and fourth embodiments, the transport robot 30 is movable forward and backward relative to both the wet processing apparatus 2 and the supercritical processing apparatus 4 while supporting the substrate S in a puddle state from the underside. Therefore, the transport robot 30 not only has the function of loading and unloading the substrate S into and from each of the wet processing apparatus 2 and the supercritical processing apparatus 4, but also has the function of horizontally reciprocating and rotating the hand 31 supporting the substrate S. In other words, the substrate S can be subjected to vibration along the horizontal direction by repeating the reciprocating and rotating operations of the hand 31. Therefore, the transport process (step S30) from the wet processing apparatus 2 to the supercritical processing apparatus 4 is divided into the following three sub-processes:
A step in which the hand 31 receives the substrate S in a puddle state;
A process in which the hand 31 reciprocates a predetermined distance in a horizontal plane while holding the substrate S in a puddle state, and rotates in forward and reverse directions to apply vibration to the substrate S;
A process of transporting the substrate S in a puddle state to the processing unit 41 of the supercritical processing apparatus 4;
The transfer control unit 96 may control the transfer robot 30 so as to execute the above steps in this order. Note that, here, the residual liquid removal process is executed when the hand 31 enters the wet-type treatment device 2 and receives the substrate S in a puddle state, but the execution timing of the residual liquid removal process is not limited to this. For example, the residual liquid removal process may be executed while the hand 31 is moving to the supercritical treatment device 4 or while the hand 31 is stopped and waiting near the supercritical treatment device 4.

In addition, in order to wait for the transport of the substrate S to the supercritical processing device 4 depending on the operating status of the supercritical processing device 4, in addition to setting the vicinity of the supercritical processing device 4 as a waiting position as described above, another waiting position may be provided. For example, if the substrate transport device 3 has a mounting table on which the substrate S in a puddle state is temporarily placed and waited, the mounting table functions as the waiting position. Therefore, a vibrator may be attached to the mounting table to impart vibration to the substrate S waiting on the mounting table. In other words, the residual liquid removal process may be performed at the waiting position where the mounting table is provided.

In addition, to perform the residual liquid removal process, the hand 31 is vibrated horizontally or rotated within a horizontal plane, but vibration may be applied in a different manner depending on the configuration of the transport robot 30. For example, the transport robot 30 may be configured to be able to move the hand 31 in the vertical direction Z. In such a case, the hand 31 holding the substrate S in a puddle state may be raised and lowered in the vertical direction Z to vibrate the substrate S.

In the first and fourth embodiments, the substrate S transported to the supercritical processing apparatus 4 is accommodated in the processing chamber 412 in a puddle state. Specifically, the substrate S is transported with the pattern-formed surface Sa facing up, and the pattern-formed surface Sa is covered with a thin liquid film LF. As shown by the dotted line in FIG. 4, the lift pins 437 rise with the lid member 413 moving to the (-Y) side and the support tray 415 pulled out. The transport device transfers the substrate S to the lift pins 437. The lift pins 437 descend, and the substrate S is placed on the support tray 415. In this way, the reception of the substrate S is completed.

At this point, the supercritical processing control unit 97 may move the support tray 415 and the lid member 413 back and forth along the Y direction while holding the substrate S in a puddle state. This back and forth movement imparts vibration to the substrate S, which causes the residual liquid to be advected and diffused (residual liquid removal process) as in the fourth embodiment. According to this embodiment, the residual liquid removal process is performed in the supercritical processing device 4 before the processing fluid in the supercritical state is brought into contact with the substrate S. Therefore, the same effect as in the fourth embodiment can be obtained.

In addition, in this embodiment, the support tray 415 and the lid member 413 are vibrated along the Y direction to perform the residual liquid removal process, but a vibrator may be attached to the support tray 415 or the lid member 413. In other words, the vibrator may be operated in response to a vibration command from the supercritical process control unit 97 to vibrate the substrate S.

Although the residual liquid removal process is performed before the pressure in the processing chamber 412 rises, the residual liquid removal process may be performed while the pressure is rising, as long as the pressure is not yet at the supercritical condition. For example, the residual liquid removal process may be performed in a subcritical state. In particular, considering the time that elapses between the execution of the residual liquid removal process and the start of contact with the processing fluid in the supercritical state, it is preferable to perform the residual liquid removal process at a timing close to the subcritical state. In other words, as the above-mentioned elapsed time increases, due to reasons such as the specific gravity of DIW being greater than that of IPA, there is a possibility that some of the DIW that has diffused into the IPA will settle on the inner bottom surface of the pattern PT, increasing the DIW concentration. It is preferable to set the timing of the execution of the residual liquid removal process taking this into consideration.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In the above-described embodiment, the residual liquid removal process is performed only once when performing the wet processing and supercritical drying process on one substrate S, but the residual liquid removal process may be performed multiple times. In other words, at least one of the first vibration application process to the third vibration application process may be performed.

The various chemical substances used in the processes of the above embodiments are only a few examples, and various substances can be used instead as long as they are in accordance with the technical concept of the present invention.

This invention can be applied to substrate processing methods and substrate processing systems in general, in which a substrate covered with a liquid film is processed with a processing fluid in a supercritical state.

REFERENCE SIGNS LIST 1...Substrate processing system 2...Wet processing apparatus 3...Substrate transfer apparatus 4...Supercritical processing apparatus 9...Control apparatus 21...Substrate holder 30...Transfer robot 31...Hand 95...Wet processing control section 96...Transfer control section 97...Supercritical processing control section 212...Chuck pin 415...Support tray AX...Rotation axis D...Radial direction LF...Liquid film PT...Pattern S...Substrate Sa...Upper surface (pattern-formed surface)
Z: vertical direction

Claims (9)

A substrate processing method for processing a substrate having a pattern-formed surface on which a pattern is formed, comprising: (a) a step of performing, in a wet processing apparatus, a wet processing of the substrate by supplying a chemical liquid to the pattern-formed surface, a rinsing processing by supplying a rinsing liquid to the pattern-formed surface, a replacement processing by supplying an organic solvent to the pattern-formed surface, and a puddle processing for forming a liquid film of the organic solvent in a puddle state on the pattern-formed surface by supplying the organic solvent to the pattern-formed surface, in this order; (b) a step of transporting the substrate from the wet processing apparatus to a supercritical processing apparatus while maintaining the puddle state; and (c) a step of drying the substrate in the supercritical processing apparatus by contacting the pattern-formed surface in the puddle state with a processing fluid in a supercritical state,
A substrate processing method, characterized in that in at least one of the steps (a), (b) and (c), the inside of the pattern is heated while maintaining a puddle state. 2. The substrate processing method according to claim 1,
The substrate processing method according to claim 1, wherein the rinsing liquid used in the step (a) has a temperature of 40 ° C. or higher and is equal to or lower than the upper limit temperature at which a puddle state can be maintained. 2. The substrate processing method according to claim 1,
The substrate processing method, wherein the step (a) comprises a first heating process of supplying a heating medium to a lower surface of the substrate opposite to the pattern formation surface in parallel with the puddle process. 4. The substrate processing method according to claim 3,
A substrate processing method, wherein the heating medium has a temperature of 80 ° C. or higher and is equal to or lower than the upper limit temperature at which a puddle state can be maintained. 2. The substrate processing method according to claim 1,
The substrate processing method, wherein the step (a) includes a second heating process in which the substrate is heated by a heater disposed opposite to the lower surface of the substrate opposite the pattern formation surface, in parallel with the puddle process. 2. The substrate processing method according to claim 1,
The step (b) includes: (b-1) receiving the substrate from the wet-treatment device with a hand of a transfer robot; (b-2) moving the hand to the supercritical treatment device while heating the substrate received from the wet-treatment device with a heater provided in the hand; and (b-3) transferring the substrate from the hand to the supercritical treatment device.
The substrate processing method comprises: 2. The substrate processing method according to claim 1,
The step (c) comprises: (c-1) placing the substrate on a support tray; (c-2) horizontally moving the support tray with the substrate placed thereon to accommodate the substrate in a supercritical processing chamber; (c-3) increasing the pressure inside the processing chamber accommodating the substrate; (c-4) contacting the processing fluid in the supercritical state with the substrate in the processing chamber to perform supercritical drying; and (c-5) heating the substrate by a heater provided on the support tray between the steps (c-1) and (c-4).
The substrate processing method comprises: 8. The substrate processing method according to claim 1 , further comprising the step of: (d) vibrating the substrate while maintaining the puddle state, before contacting the processing fluid in the supercritical state with the pattern formation surface, thereby mixing the rinsing liquid remaining in the pattern with the organic solvent. 1. A substrate processing system for processing a substrate having a patterned surface on which a pattern is formed, comprising:
a wet processing apparatus which performs, in this order, a wet processing of the substrate by supplying a chemical liquid to the pattern-formed surface, a rinsing processing by supplying a rinsing liquid to the pattern-formed surface, a replacement processing by supplying an organic solvent to the pattern-formed surface, and a puddle processing for forming a liquid film of the organic solvent in a puddle state on the pattern-formed surface by supplying the organic solvent to the pattern-formed surface;
a supercritical processing apparatus that dries the substrate by contacting the puddle-like pattern-formed surface with a processing fluid in a supercritical state;
a substrate transport device that transports the substrate from the wet processing device to a supercritical processing device while the substrate is in the puddle state,
At least one of the wet processing device, the substrate transport device and the supercritical processing device heats the inside of the pattern while maintaining the puddle state.

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