JP2024045869A - Substrate processing device and substrate processing method - Google Patents

Abstract

To prevent the re-deposition of a liquid on a substrate when the liquid is removed from the substrate by a treatment fluid.SOLUTION: A substrate processing device includes a support tray having a flat plate shape and supporting a substrate to be placed on a substrate mounting surface on its upper surface, a chamber having an internal space capable of accommodating the support tray supporting the substrate, and a fluid supply part supplying a process fluid to the internal space. The support tray supports the substrate with its upper surface covered with a fluid film at a predetermined angle tilt from a horizontal posture.SELECTED DRAWING: Figure 3

Description

The present invention relates to a substrate processing apparatus and a substrate processing method for processing a substrate to which a liquid is attached using a processing fluid in a supercritical state.

When a substrate is wet-processed with a liquid, the liquid adheres to the top surface of the substrate. As a substrate processing apparatus for drying the substrate after this wet processing, for example, the apparatus described in Patent Document 1 is known. In this apparatus, a shallow recess is provided in a flat support tray, and the substrate is supported in the recess in a horizontal position with a minute gap between the substrate and the top surface of the support tray. In this state, the support tray is carried into a processing chamber, and the chamber is filled with a processing fluid in a supercritical state to process the substrate (supercritical processing). The substrate may be carried into the processing chamber with its surface covered with a liquid film to prevent the surface from being exposed, and to prevent the surface from collapsing if a fine pattern is formed on the surface.

JP 2021-009875 A

It is assumed that the liquid that constitutes the liquid film that covers the substrate when it is loaded is replaced by the processing fluid and removed from the substrate surface. However, if some of the liquid gets into the narrow gap between the bottom surface of the substrate and the top surface of the support tray, replacement by the processing fluid does not proceed sufficiently, and as a result, even at the final stage of processing, the liquid may remain in the chamber and re-adhere to the substrate, which can be a problem.

Therefore, there is a need to more efficiently remove the liquid that forms the liquid film from the substrate during the initial stage of supercritical processing. In this regard, there is still room for improvement in the above-mentioned conventional techniques.

The present invention has been made in view of the above problems, and provides a substrate processing apparatus and a substrate processing method that can prevent the liquid from re-adhering to the substrate when the liquid is removed from the substrate by a processing fluid. The purpose is to

One aspect of the present invention is a substrate processing apparatus that processes a substrate with a processing fluid in a supercritical state, the support tray having a flat plate shape and supporting the substrate placed on an upper substrate mounting surface thereof. a chamber having an internal space that can accommodate the support tray that supports the substrate; and a fluid supply unit that supplies the processing fluid to the internal space, the support tray having an upper surface covered with a liquid film. The substrate processing apparatus supports the substrate in a tilted state at a predetermined angle from a horizontal position.

Another aspect of the present invention is a substrate processing method comprising the steps of placing a substrate having a liquid film formed on the upper surface of a flat support tray and accommodating the substrate in an internal space of a chamber, and supplying the processing fluid to the internal space to process the substrate with the processing fluid in a supercritical state, the support tray supporting the substrate with the liquid film on the upper surface thereof at a predetermined angle from a horizontal position.

In supercritical processing using a supercritical processing fluid, the interior space of the chamber goes from a normal pressure state immediately after the substrate is introduced, to a high pressure state of a supercritical state as the processing fluid is introduced. Shows large pressure changes. During this process, the processing fluid gradually dissolves into the liquid film on the substrate and the pressure increases, causing the fluidity of the liquid that makes up the liquid film to rapidly increase, to the point where it becomes impossible to maintain the liquid film. Increased liquidity. At this time, the liquid flows down from the substrate all at once, but when the substrate is held in a horizontal position, it is impossible to predict where the liquid will start falling. Therefore, the dropped liquid may not be removed from the support tray and may enter the gap between the substrate and the support tray.

In contrast, in the invention configured as described above, the substrate is held in an inclined state within the chamber, so the direction and position at which the liquid will flow down along the inclination of the substrate surface can be predicted. Therefore, measures can be taken in advance to prevent the liquid from flowing around at positions where the liquid is predicted to fall. This makes it possible to prevent the liquid that has fallen from the substrate from remaining between the substrate and the support tray, and to prevent the liquid from re-adhering to the substrate. The inclination of the substrate is small enough that a liquid film can be maintained on the substrate under normal pressure.

As described above, in the present invention, by supporting the substrate in a chamber in an inclined position from the horizontal, it is possible to predict the direction and position of the liquid that maintains a liquid film under normal pressure when it flows off the substrate during processing. This makes it possible to appropriately drain the liquid that flows off the substrate and prevent the liquid from re-adhering to the substrate.

1 is a diagram showing the overall configuration of a substrate processing apparatus to which the present invention can be applied. FIG. 2 illustrates a first embodiment of a support tray. FIG. 3 is a diagram showing how a substrate is supported by the support tray of the first embodiment. 5A and 5B are diagrams showing dimensional relationships in substrate support by the support tray of the first embodiment. FIG. 7 is a diagram showing how a substrate is supported by a support tray according to a second embodiment. 13A and 13B are diagrams showing a manner in which a substrate is supported by a support tray according to a third embodiment. It is a figure which shows the support aspect of the board|substrate by the support tray of 4th Embodiment. 13A to 13C are diagrams showing a manner in which a substrate is supported by a support tray according to a fifth embodiment.

Below, we will explain several embodiments of the substrate processing apparatus according to the present invention. Although there are some differences between the embodiments in the structure of the support tray, which will be described later, the basic device configuration is the same. Therefore, we will first explain the overall configuration of the substrate processing apparatus, and then we will explain the characteristic parts of each embodiment.

<Overall configuration of the device>
FIG. 1 is a diagram showing the overall configuration of a substrate processing apparatus to which the present invention can be applied. The substrate processing apparatus 1 is an apparatus for processing the upper surface of various substrates such as semiconductor substrates using a supercritical fluid. For example, the substrate processing apparatus 1 can perform a supercritical drying process in which a liquid adhering to a substrate is replaced with a supercritical processing fluid to dry the substrate. In order to uniformly indicate the directions in each of the following figures, an XYZ orthogonal coordinate system is set as shown in FIG. Here, the XY plane is a horizontal plane, and the Z direction represents a vertical direction. More specifically, the (-Z) direction represents vertically downward.

The "substrate" in this embodiment can be any of a variety of substrates, including 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. In the following, a substrate processing apparatus used primarily for processing semiconductor wafers will be described with reference to the drawings, but the apparatus can also be used for processing the various substrates exemplified above.

The substrate processing apparatus 1 comprises a processing unit 10, a transfer unit 30, a supply unit 50, and a control unit 90. The processing unit 10 is the main entity that carries out the supercritical drying process, and the transfer unit 30 receives unprocessed substrates transported by an external transport device (not shown) and transports them into the processing unit 10, and also transfers processed substrates from the processing unit 10 to the external transport device. The supply unit 50 supplies the chemicals and power required for processing to the processing unit 10 and the transfer mechanism 30.

The control unit 90 controls each part of these devices to realize predetermined processing. For this purpose, the control unit 90 is equipped with a CPU 91 that executes various control programs, a memory 92 that temporarily stores processing data, a storage 93 that stores the control programs executed by the CPU 91, and an interface 94 for exchanging information with users and external devices. The operation of the devices, which will be described later, is realized by the CPU 91 executing the control programs written in advance in the storage 93 and causing each part of the devices to perform a predetermined operation.

The processing unit 10 has a structure in which a processing chamber 12 is mounted on a pedestal 11. The processing chamber 12 is composed of a combination of several metal blocks, and has a hollow interior to form a processing space SP. The substrate S to be processed is carried into the processing space SP and undergoes processing. A slit-shaped opening 121 that extends in the X direction is formed in the (-Y) side surface of the processing chamber 12, and the processing space SP and the external space communicate with each other through the opening 121.

A lid member 13 is provided on the (-Y) side surface of the processing chamber 12 so as to close the opening 121. A flat support tray 15 is attached to the (+Y) side surface of the lid member 13 in a horizontal position, and the upper surface of the support tray 15 serves as a support surface on which the substrate S can be placed. The lid member 13 is supported by a support mechanism (not shown) so as to be horizontally movable in the Y direction.

The lid member 13 can be moved forward and backward with respect to the processing chamber 12 by a movement mechanism 53 provided in the supply unit 50. Specifically, the advancement/retraction mechanism 53 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 lid member 13 in the Y direction. move it to The advancing/retracting mechanism 53 operates according to control commands from the control unit 90.

As shown by the dotted line in FIG. 1, when the support tray 15 is pulled out from the processing space SP through the opening 121 by moving the lid member 13 in the (-Y) direction, access to the support tray 15 is disabled. It becomes possible. That is, it becomes possible to place the substrate S on the support tray 15 and to take out the substrate S placed on the support tray 15. On the other hand, by moving the lid member 13 in the (+Y) direction, the support tray 15 is housed in the processing space SP, as shown by the solid line in FIG. When the substrate S is placed on the support tray 15, the substrate S is carried into the processing space SP together with the support tray 15.

The lid member 13 moves in the (+Y) direction to close the opening 121, thereby sealing the processing space SP. Although not shown, a seal member is provided between the (+Y) side surface of the lid member 13 and the (-Y) side surface of the processing chamber 12 to keep the processing space SP airtight. The lid member 13 is fixed to the processing chamber 12 by a locking mechanism (not shown). In this way, with the processing space SP kept airtight, processing of the substrate S is carried out within the processing space SP.

In supercritical drying, the main purpose of which is to dry a substrate while preventing pattern collapse due to the surface tension of the liquid, the substrate S is brought in with its upper surface Sa covered with a liquid film to prevent the upper surface Sa from being exposed and causing pattern collapse. As the liquid that constitutes the liquid film, for example, an organic solvent with a relatively low surface tension such as isopropyl alcohol (IPA) or acetone can be suitably used.

In this embodiment, a fluid of a substance that can be used in supercritical processing, such as carbon dioxide, is supplied in a gaseous or liquid state to the processing unit 10 from a fluid supply section 57 provided in the supply unit 50. Carbon dioxide is a chemical suitable for supercritical drying processing because it reaches a supercritical state at relatively low temperatures and pressures and has the property of dissolving organic solvents that are often used in substrate processing well.

The fluid is filled into the processing space SP, and when the processing space SP reaches an appropriate temperature and pressure, the fluid becomes supercritical. The substrate S is then processed by the supercritical fluid in the processing chamber 12. The supply unit 50 is provided with a fluid recovery section 55, and the fluid after processing is recovered by the fluid recovery section 55. The fluid supply section 57 and the fluid recovery section 55 are controlled by the control unit 90.

The transfer unit 30 is responsible for transferring the substrate S between an external transport device and the support tray 15. For this purpose, the transfer unit 30 is equipped with a main body 31, a lifting member 33, a base member 35, and lift pins 37, each of which is provided in multiple numbers. The lifting member 33 is a columnar member extending in the Z direction, and is supported by the main body 31 so as to be freely movable in the Z direction.

A base member 35 having a substantially horizontal upper surface is attached to the top of the lifting member 33, and a number of lift pins 37 are erected upward from the upper surface of the base member 35. Each of the lift pins 37 supports the substrate S in a horizontal position from below by abutting its upper end against the underside of the substrate S. In order to stably support the substrate S, it is desirable to provide three or more lift pins 37 whose upper ends have the same height.

The lifting member 33 can be moved up and down under the control of a lifting control unit 51 provided in the supply unit 50. Specifically, the main body 31 of the transfer unit 30 is provided with a linear motion mechanism (not shown) such as a linear motor, a linear guide, a ball screw mechanism, a solenoid, or an air cylinder, and such a linear motion mechanism is controlled by the lifting control unit 51 to move the lifting member 33 in the Z direction. The lifting control unit 51 operates in response to a control command from the control unit 90.

As the elevating member 33 moves up and down, the base member 35 moves up and down, and the plurality of lift pins 37 move up and down integrally with this. Thereby, the transfer of the substrate S between the transfer unit 30 and the support tray 15 is realized. The specific details are as follows.

As will be described later, the support tray 15 is provided with through holes corresponding to the lift pins 37 of the transfer unit 30. That is, through holes are formed at positions corresponding to directly above each lift pin 37 when the support tray 15 is pulled out from the processing chamber 12 . When the base member 35 rises as the elevating member 33 moves up and down, the lift pin 37 passes through the through hole of the support tray 15 and its tip reaches a position higher than the upper surface of the support tray 15. In this state, the unprocessed substrate S is transferred to the lift pins 37 by an external transfer means, for example, a transfer robot having a hand capable of holding the substrate.

When the lift pins 37 that support the substrate S are lowered, the substrate S is also lowered, and the lift pins 37 are further lowered from the state where the substrate S is in contact with the upper surface of the support tray 15, so that the substrate S is transferred from the lift pins 37 to the support tray 15. Then, it is in a state where it is supported by the support tray 15. In this way, the substrate S is carried into the substrate processing apparatus 1. Finally, the lift pin 37 descends to a position where it does not interfere with the opening/closing operation of the lid member 13.

The processed substrate S is removed from the substrate processing apparatus 1 by the reverse operation to that described above. That is, while the substrate S is supported on the support tray 15, the lift pins 37 rise and lift the substrate S. The hand of the transport robot is inserted between the bottom surface of the substrate S thus created and the top surface of the support tray 15, and the substrate S can be transferred from the lift pins 37 to the transport robot.

As described above, in this substrate processing apparatus 1, the supercritical drying process is performed on the substrate S. The sequence of this process is as follows. First, the substrate S whose upper surface Sa is covered with a liquid film is carried in from the outside and placed on the support tray 15 . When the support tray 15 enters the internal space SP of the processing chamber 12, the substrate S is accommodated in the internal space SP. Then, with the internal space SP closed by the lid member 13, a gas or liquid processing fluid is introduced into the internal space SP from the fluid supply section 57. The processing fluid is pressurized in the internal space SP to become supercritical, thereby replacing the liquid on the substrate S with the supercritical processing fluid. By continuing the supply of the processing fluid from the fluid supply unit 57 and the discharge by the fluid recovery unit 55 for a certain period of time, the liquid separated from the substrate S is discharged. Finally, the processing fluid undergoes a phase transition from a supercritical state to a gas phase without passing through a liquid phase and is discharged, thereby leaving the substrate S in a dry state.

Next, several embodiments of the support tray 15 (support trays 151 to 155) in the substrate processing apparatus 1 described above will be described. Although the structure of the support tray is different between each embodiment, other points are common, and the operation thereof is also as described above. In addition, in the description of each embodiment below, components having common or similar structures and functions are given common or corresponding symbols, and the description thereof will not be repeated. Further, for configurations that have clear correspondences between multiple drawings, reference numerals may be omitted in some of the drawings.

<First embodiment>
FIG. 2 is a diagram showing a first embodiment of the support tray. As shown in FIG. 2(a), the support tray 151 of the first embodiment has a horizontal and flat upper surface 1511 of a flat main body 1510 with a circular shape corresponding to the planar size of the substrate S. It has a general outline in which a recess 1512 having a diameter slightly larger than the diameter of the substrate S is provided. A bottom surface 1513 of the depression 1512 is a horizontal surface.

Note that the depression 1512 partially extends to the side surface 1514 of the support tray 151. In other words, the side wall surface of the recess 1512 is not circular but partially cut out. Therefore, in this cutout portion 1515, a portion of the bottom surface 1513 of the recess 1512 is directly connected to the side surface 1514. In this example, such cutouts 1515 are provided at both ends of the X side and at the (+Y) side of the support tray 151, and the bottom surface 1513 is directly connected to the side surface 1514 at these locations.

In addition, at positions on the bottom surface 1513 corresponding to the lift pins 37 of the loading/unloading unit 30, through holes 1514 are drilled for inserting the lift pins 37. The lift pins 37 are raised and lowered through the through holes 1514, thereby realizing a state in which the substrate S is housed in the recess 1512 and a state in which it is lifted above this.

A plurality of support pins 16 are arranged around the periphery of the recess 1512. The number of support pins 16 to be provided is arbitrary, but from the viewpoint of stably supporting the substrate S, it is desirable that the number is 3 or more. As shown in FIGS. 2(b) and 2(c), the support pin 16 has a height regulating portion 161 and a horizontal position regulating portion 162.

The height restriction portion 161 has a flat upper surface and abuts against the peripheral edge of the lower surface Sb of the substrate S, thereby supporting the substrate S and restricting its position in the height direction (Z direction). On the other hand, the horizontal position restriction portion 162 extends above the upper end of the height restriction portion 161 and abuts against the side of the substrate S, thereby restricting the position of the substrate S in the horizontal direction (XY direction). By using such support pins 16, the substrate S is supported at a predetermined position within the recess 1512 and at a predetermined gap from the bottom surface 1513.

FIG. 3 is a diagram showing how the substrate is supported by the support tray of the first embodiment. As shown in the top view of FIG. 3(a), in this example, three support pins 16a, 16b, and 16c are arranged at equal angular intervals. On the support tray 151, the substrate S is supported at a horizontal position and height regulated by support pins 16a, 16b, and 16c. At this time, the substrate S is supported with a portion protruding toward the (+Y) side beyond the (+Y) side end of the support tray 151.

Further, among the support pins, the support pin 16a disposed closest to the (-Y) side supports the substrate S at a higher position than the other support pins 16b and 16c. That is, the height regulating portion 161a of the support pin 16a is located at a higher position than the height regulating portions 161b, 161c of the other two support pins 16b, 16c. Therefore, as shown in FIG. 3(b), the substrate S is supported in an inclined state with a downward slope in the (+Y) direction. The dashed arrows in FIGS. 3(a) and 3(b) indicate the direction in which the substrate S is tilted.

When the substrate S is brought into the processing space SP of the processing chamber 12, its upper surface Sa is covered with a liquid film LF. The liquid constituting the liquid film LF is, for example, an organic solvent such as IPA. As described below, the inclination of the substrate S is small enough that the liquid film LF is maintained by its surface tension even when the substrate S is brought into the processing space SP under an atmospheric pressure environment. Therefore, as shown in FIG. 3(b), the substrate S has its upper surface Sa covered with a liquid film LP even in the processing space SP. From this state, the processing fluid is introduced into the processing space SP.

As the processing fluid is introduced into the processing space SP and is eventually pressurized to a supercritical state, part of the processing fluid dissolves into the liquid film LF, and as a result, the viscosity of the liquid that constitutes the liquid film LF gradually decreases and its fluidity increases. When the viscosity of the liquid decreases to a certain level, it becomes impossible to maintain the liquid film on the substrate S, and as shown in Figure 3(c), the liquid film LF is destroyed and the liquid flows off the substrate S in one go. In Figure 3(c), the symbol F indicates the processing fluid that fills the processing space SP.

At this time, since the substrate S is tilted in the (+Y) direction and is supported with its (+Y) side end projecting beyond the end of the support tray 151, the liquid that has flowed down will not adhere to the support tray 151. First, it directly flows down to the bottom of the processing space SP. The liquid that has flowed down is carried along with the processing fluid F to the downstream side, that is, in the (-Y) direction, and is finally discharged from the processing space SP. This prevents the liquid from flowing between the lower surface Sb of the substrate S and the bottom surface 1513 of the recess 1512. Therefore, in this embodiment, the problem of liquid remaining between the substrate S and the support tray 151 and re-adhering to the substrate S can be avoided.

FIG. 4 is a diagram showing the dimensional relationship in substrate support by the support tray of the first embodiment. As shown in FIG. 4(a), the inclination of the normal to the substrate top surface Sa shown by the dashed line with respect to the vertical axis (Z axis) is denoted by θ, and the slope between the bottom surface Sb of the substrate S and the top surface of the support tray 151 (from Specifically, the minimum gap between the recess 1512 and the bottom surface 1513) is represented by G, and the amount of protrusion of the substrate S from the support tray 151 at the (+Y) side end is represented by P. Note that although the inclination angle θ of the substrate S is expressed here as the inclination of the normal line to the vertical axis, this is technically equivalent to the inclination of the upper surface Sa with respect to the horizontal plane.

The upper limit of the tilt angle θ is restricted by conditions such as the ability to maintain the liquid film LF on the substrate S in an atmospheric pressure environment, not interfering with loading into and unloading from the processing space SP, and not impeding the flow of processing fluid within the processing space SP. Taking these conditions into consideration, the inventors of the present application have found that it is desirable to set the tilt angle θ to, for example, 5 degrees or less.

On the other hand, the lower limit of the tilt angle θ can be considered as follows. Under a high pressure environment near the critical point of the processing fluid, the viscosity of the liquid in which the processing fluid is dissolved is extremely low. Therefore, the direction in which the liquid flows is determined by a very slight inclination of the substrate S. Therefore, in principle, the tilt angle θ can be set to any size greater than zero.

However, when considering the installation environment of this type of substrate processing apparatus 1, even if sufficient adjustments are made at the time of installation, it is inevitable that a certain degree of tilt will remain. According to the knowledge of the present inventors, the tilt of the apparatus in a well-adjusted state is a maximum of about 0.5 degrees. Therefore, even if the apparatus body has such a tilt, in order to tilt the substrate S in the desired direction, it is desirable to set the tilt angle θ to be larger than the maximum tilt angle (0.5 degrees) of the apparatus body. In order to ensure a significant tilt even in such a case, the tilt angle θ can be set to, for example, 1 degree or more. Therefore, the appropriate range of the tilt angle θ can be greater than 0.5 degrees and less than 5 degrees, more preferably 1 degree or more and less than 5 degrees.

The amount of overhang P of the substrate S from the support tray 151 may be set to zero or more, more preferably greater than zero, so that the flowing liquid falls directly. However, it is possible to substantially eliminate residual liquid without providing such an overhang. That is, in the support tray 151 of this embodiment, a part of the recess 1512 provided on the upper surface 1511 to accommodate the substrate S is cut out. That is, the bottom surface 1513 of the recess 1512 is directly connected to the side surface 1514 of the support tray 151. Therefore, even if a part of the liquid flowing down from the substrate S adheres to the bottom surface 1513 of the recess 1512, it is expected that it will be discharged from this connection part during the process. To further enhance this effect, the bottom surface 1513 may be partially inclined toward the connection part with the side surface.

Further, the minimum gap G between the substrate S and the support tray 151 is preferably larger than 0.5 mm. According to the inventor's findings, when the gap is 0.5 mm or less, as shown in FIG. 4(b), the liquid Lq forming the liquid film wraps around the lower surface Sb of the substrate S due to capillary action, and the support tray There is a high possibility of residual adhesion in the gap with 151.

Although the processing fluid in a supercritical state dissolves the liquid Lq well, the liquid Lq that has entered such a narrow gap has a small contact area with the processing fluid, making it difficult to completely replace it with the processing fluid. Even if it were possible, it would take a long time. The liquid remaining in the gap between the substrate S and the support tray 151 in this way is one of the causes of the liquid reattaching to the substrate S. By making the minimum gap G larger than 0.5 mm, it is possible to effectively suppress this type of liquid from seeping around.

Conventional technology assumes that the substrate is held in a horizontal position, but in reality, there may be cases where the entire device is slightly tilted as described above, or where the top surface of the support tray is tilted within the tolerance range of the processing and assembly of each component. For this reason, the direction in which the liquid flows down when the viscosity of the liquid decreases under high pressure cannot be controlled, and there is no reproducibility. The liquid that flows out in this way ends up wrapping around the gap between the substrate and the support tray.

On the other hand, in the present embodiment, it is possible to tilt the substrate S in a desired direction by taking into account the tilt of the device, so that when the liquid film breaks on the substrate S, The direction and position of the liquid flowing down can be controlled. Therefore, by providing a means for discharging the falling liquid at the position, it is possible to prevent the liquid from flowing around. In this embodiment, by making the end of the substrate S in the direction in which the liquid flows down protrude beyond the support tray 151, the liquid can fall directly downward without contacting the support tray 151.

Note that the concepts regarding the inclination angle θ, the minimum gap G, and the protrusion amount P described here can be similarly applied to each embodiment described below.

Second Embodiment
5 is a diagram showing a manner in which a substrate is supported by a support tray according to the second embodiment. More specifically, FIG. 5(a) is a diagram showing the appearance of a support tray 152 according to the second embodiment, and FIG. 5(b) is a cross-sectional view taken along line A-A thereof. In this embodiment, a support pin 16b provided near the (-X) end of the support tray 152 is configured to support the substrate S at a higher position than the other support pins 16a and 16c. The two support pins 16a and 16c may support the substrate S at the same height. Also, the support pin 16a may support the substrate S at a position lower than the support pin 16b and higher than the support pin 16c.

In this configuration, as shown by the dashed arrows in Figures 5(a) and 5(b), the upper surface Sa of the substrate S is supported with a downward slope toward the (+X) direction. Therefore, when the liquid film LF on the substrate S breaks, the liquid Lq flows down from the (+X) side end of the substrate S. In this case, too, as shown in Figure 5(b), a notch 1526 is provided at the (+X) side end of the support tray 152, and the substrate S is further protruded from the support tray 152, so that it is possible to more effectively prevent the liquid from flowing around to the lower surface Sb of the substrate. On the other hand, a notch is not essential at the (+Y) side end of the support tray 152.

Although the substrate S is tilted toward the (+X) side in this embodiment, it is equivalent to tilt the substrate S toward the (-X) side. In this case, the support pin 16c near the (+X) end of the support tray 152 may support the substrate S at a higher position than the other support pins 16a and 16b.

Third Embodiment
6 is a diagram showing a manner in which a substrate is supported by a support tray of the third embodiment. In the support tray 153 of this embodiment, the support pin 16a, which is the closest to the (-Y) side among the three support pins 16a, 16b, and 16c, is configured to support the substrate S at a position relatively lower than the other support pins 16b and 16c. Therefore, the substrate S is supported in an inclined state having a downward gradient toward the (-Y) side. This causes the liquid on the substrate S to flow in the (-Y) direction and flow down from the (-Y) side end of the substrate S onto the upper surface 1531 of the support tray 153.

To prevent this liquid from seeping around to the underside of the substrate S, the upper surface 1531 of the support tray 153 does not have any steps to form recesses, and is instead provided with a slope that slopes downward in the (-X) and (+X) directions. The liquid that flows down from the substrate S to the support tray 153 flows down along this slope 1531, and falls downward from the (-X) and (+X) side end faces of the support tray 153. This prevents the liquid from getting between the substrate S and the support tray 153.

Figure 6 (c) shows a modified example of the third embodiment. In this modified example, the support tray 153a is provided with a through hole 1537 that penetrates from the upper surface 1531 to the lower surface. The upper surface 1531 is inclined so as to guide the liquid that has flowed down from the substrate S toward the through hole 1537. With this configuration, the liquid that has flowed down onto the support tray 153 can be more efficiently caused to fall downward and prevented from remaining on the upper surface 1531 of the support tray 153.

In the third embodiment and its modifications, the liquid on the substrate S flows down in the (-Y) direction. When the liquid flows down, the inside of the processing space SP is filled with the processing fluid flowing in the (-Y) direction, so the liquid separated from the substrate S follows this flow further in the (-Y) direction, that is, towards the substrate S. It is carried away from the body and discharged. Therefore, the probability of the liquid re-adhering to the substrate S can be lowered than when the liquid is caused to flow down in the (+Y) direction.

<Fourth embodiment>
FIG. 7 is a diagram showing how the substrate is supported by the support tray of the fourth embodiment. In each of the embodiments described above, the substrate S is supported in an inclined state on the support tray 15 by making the substrate support heights of the support pins 16 (16a, 16b, 16c) different. On the other hand, in the support tray 154 of the fourth embodiment, by making the bottom surface 1543 of the recess 1542 provided on the top surface 1541 an inclined surface, even though each support pin 16 has the same structure, it is possible to hold the substrate S in an inclined state. It is possible to support.

In this example, the bottom surface 1543 of the depression 1542 is inclined toward the (+Y) direction, as shown by the broken line arrow in FIGS. 7(a) and 7(b). With such a structure as well, the liquid on the substrate S can be caused to flow down in the (+Y) direction, and can be caused to fall downward from the (+Y) side end of the substrate S. Further, even if the liquid flows around to the lower surface side of the substrate S, since the upper surface of the support tray 154 itself is inclined, the liquid can be expected to flow down along the inclined direction.

Fifth Embodiment
8 is a diagram showing a manner in which a substrate is supported by a support tray according to a fifth embodiment. In contrast to the fourth embodiment, the support tray 155 of this embodiment has an upper surface 1551 that is inclined downward in the (-Y) direction. Therefore, the liquid on the substrate S flows in the (-Y) direction and falls onto the upper surface 1551 of the support tray 155. In this case, it is more preferable that the upper surface 1551 of the support tray 155 is inclined in the (-X) direction and the (+X) direction. Also, a through hole may be provided to allow the liquid to fall.

<Others>
As explained above, in each of the above embodiments, the substrate processing apparatus 1 corresponds to the "substrate processing apparatus" of the present invention, and the processing chamber 12 and the lid member 13 correspond to the "chamber" and "lid" of the present invention, respectively. It functions as a component. Moreover, the support pin 16 functions as a "support part" of the present invention. Furthermore, the processing space SP corresponds to the "internal space" of the present invention.

Further, in the support tray 151 of the first embodiment, the bottom surface 1513 of the recess 1512 corresponds to the "substrate mounting surface" of the present invention, and the notch 1516 corresponds to the "ejection guide portion" of the present invention. Further, in the support tray 153 of the third embodiment and its modification 153a, the inclined surface 1531 and the through hole 1537 correspond to the "ejection guide portion" of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications can be made to the above-described embodiments without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the substrate S is supported at a distance from the upper surface of the support tray 15 by the support pins 16 provided on the upper surface of the support tray 15. However, instead of providing the support pins 16, a protrusion may be provided on the upper surface of the support tray to support the substrate. In this case, the protrusion corresponds to the "support portion" of the present invention.

In addition, in the above embodiment, the support tray 15 is provided with through holes for inserting the lift pins 37, and these through holes also have the effect of draining liquid adhering to the support tray 15. However, the support tray may be configured without such through holes. Rather, since liquid is more likely to remain because discharge from the through holes cannot be expected, the liquid residue prevention effect of the present invention is considered to function more effectively. Similarly, the present invention functions effectively regardless of whether the support tray has a recess for accommodating a substrate.

In addition, the various chemical substances in the above embodiments, such as IPA and carbon dioxide, are given as representative examples of substances that may be used, and do not mean that the application of the present invention is limited to technologies that use these substances.

As described above by way of example of specific embodiments, in the present invention, the support tray can support a substrate with at least a portion of the peripheral edge of the substrate protruding outward beyond the outer edge of the support tray when viewed from above, and with the substrate tilted toward the protruding peripheral edge. With this configuration, liquid flowing off the substrate can be allowed to fall directly downward without coming into contact with the support tray, effectively preventing liquid from getting between the substrate and the support tray.

For example, the substrate mounting surface may be provided with a discharge guide portion that guides the liquid that forms a liquid film and falls from the substrate from the substrate mounting surface to below the support tray. When it is unavoidable that the liquid flowing down from the substrate will adhere to the substrate mounting surface, providing such a discharge guide portion can facilitate the discharge of the liquid from the substrate mounting surface.

Specifically, for example, a recess that is recessed downward and has a planar size that can accommodate a substrate is provided on the upper surface of the support tray, the flat bottom surface of the recess forms the substrate placement surface, and at least a portion of the bottom surface extends to the outer edge of the support tray and connects to the side of the support tray, and the support tray may support the substrate such that the substrate is tilted toward a portion of the periphery that is located above the connection between the bottom surface and the side, in which case the connection portion forms the discharge guide portion.

For example, the discharge guide portion can be provided as a through hole that penetrates from the substrate placement surface to the underside of the support tray. With this configuration, liquid adhering to the substrate placement surface can be guided to the through hole, facilitating rapid discharge.

For example, the discharge guide portion can be provided as an inclined surface with a downward slope from the substrate placement surface toward the side of the support tray. With this configuration, liquid adhering to the substrate placement surface can flow down along the inclined surface, facilitating rapid discharge.

Further, for example, the substrate mounting surface itself may be inclined with respect to a horizontal surface. According to such a configuration, by placing the substrate parallel to the substrate mounting surface, it is possible to support the substrate in an inclined state. Further, the attached liquid can be caused to flow down along the inclined surface and can be prevented from remaining on the substrate mounting surface.

For example, the support tray may be provided with multiple support portions that partially abut the underside of the substrate and support the substrate while spaced upward from the upper surface of the support tray. With this configuration, it is possible to stably support the substrate while providing a predetermined gap between the underside of the substrate and the upper surface of the support tray.

In this case, at least one of the multiple support parts may have a different height from the substrate placement surface than the other support parts. With this configuration, the substrate can be supported at an angle by varying the height of the support parts.

The processing fluid may also be introduced into the internal space in a gas or liquid state and converted to a supercritical state within the internal space. With this configuration, when the substrate on which the liquid film has been formed is pressurized from a state in which it is contained in the internal space to a supercritical state, the viscosity of the liquid forming the liquid film decreases and there is a moment when the liquid flows down from the substrate in one go. By flowing down the liquid in one go in this way, it is possible to suppress residual liquid.

Further, for example, the processing fluid may be carbon dioxide, and the liquid constituting the liquid film may be an organic solvent. Since carbon dioxide transitions to a supercritical state at a relatively low temperature and low pressure compared to other chemical substances, it can be suitably applied to this type of treatment. Furthermore, since carbon dioxide dissolves organic solvents well, it is particularly effective as a processing fluid used for the purpose of replacing organic solvents.

The substrate processing apparatus according to the present invention may also be configured such that an opening is provided on the side of the chamber that connects the internal space with the external space, and further includes a lid member that closes the opening, and an advancing/retreating mechanism that moves the lid member forward and backward relative to the opening, and the support tray is integrally connected to the lid member, so that the support tray is housed in the internal space when the lid member closes the opening. With this configuration, the support tray can be moved in and out of the chamber by moving the lid member forward and backward, and the lid member is robustly configured to close the chamber whose internal space becomes high pressure, so that the support tray can be firmly supported.

In the present invention, the "predetermined angle" can be, for example, an angle greater than 0.5 degrees and less than 5 degrees. According to the inventor's findings, the tilt angle of the substrate that can maintain a liquid film on the substrate under normal pressure, can control the flow direction of the liquid under high pressure, and is not affected by the tilt of the device body can be greater than 0.5 degrees and less than 5 degrees, and more preferably, can be greater than 1 degree and less than 5 degrees.

The present invention can be applied to all substrate processing techniques in which a substrate having a liquid attached to its surface is processed using a processing fluid in a supercritical state.

1 Substrate processing apparatus 12 Processing chamber (chamber)
13 Lid member 15 Support tray 16 Support pin (support portion)
53 Advance/retreat mechanism 57 Fluid supply unit 121 Opening 1513 Recess (substrate placement surface)
1516 Notch (ejection guide part)
1531 Inclined surface (ejection guide portion)
1537 Through hole (discharge guide part)
F Processing fluid LF Liquid film S Substrate SP Processing space (internal space)

Claims (14)

In a substrate processing apparatus that processes a substrate using a processing fluid in a supercritical state,
a support tray that has a flat plate shape and supports the substrate placed on the substrate placement surface on the upper surface thereof;
a chamber having an internal space capable of accommodating the support tray that supports the substrate;
a fluid supply unit that supplies the processing fluid to the internal space,
In the substrate processing apparatus, the support tray supports the substrate, the upper surface of which is covered with a liquid film, in a state tilted at a predetermined angle from a horizontal position. The support tray is configured such that at least a part of the peripheral edge of the substrate protrudes outward beyond the outer edge of the support tray when viewed from above, and the substrate is tilted toward the protruding peripheral edge. The substrate processing apparatus according to claim 1, which supports a substrate. The substrate processing apparatus according to claim 1, wherein the substrate placement surface is provided with a discharge guide portion that guides the liquid that constitutes the liquid film and falls from the substrate from the substrate placement surface downward below the support tray. A recess having a planar size that can accommodate the substrate and receding downward is provided on the upper surface of the support tray, a flat bottom surface of the recess serves as the substrate mounting surface, and at least a portion of the bottom surface is extending to an outer edge of the support tray and connected to a side surface of the support tray;
The support tray supports the substrate so that the substrate is tilted toward a portion of the peripheral edge located above a connecting portion between the bottom surface and the side surface, and the connecting portion forms the ejection guide portion. , The substrate processing apparatus according to claim 3. The substrate processing apparatus according to claim 3, wherein the discharge guide portion is a through hole that penetrates from the substrate placement surface to the underside of the support tray. The substrate processing apparatus according to claim 3, wherein the discharge guide portion is an inclined surface having a downward slope from the substrate placement surface toward the side surface of the support tray. The substrate processing apparatus according to claim 1, wherein the substrate mounting surface is inclined with respect to a horizontal surface. 8. The support tray according to claim 1, wherein the support tray is provided with a plurality of support parts that partially abut the lower surface of the substrate and support the substrate while being spaced upward from the upper surface of the support tray. The substrate processing apparatus according to any one of the above. The substrate processing apparatus according to claim 8, wherein at least one of the plurality of support parts has a height different from the substrate mounting surface than the other support parts. An opening is provided on a side surface of the chamber to communicate the internal space with an external space,
The container further includes a cover member that closes the opening, and an advance/retract mechanism that moves the cover member toward and away from the opening,
8. The substrate processing apparatus according to claim 1, wherein the support tray is integrally connected to the lid member, and the support tray is accommodated in the internal space when the lid member closes the opening. The substrate processing apparatus according to any one of claims 1 to 7, wherein the predetermined angle is greater than 0.5 degrees and less than 5 degrees. placing the substrate on the upper surface of which the liquid film is formed on the upper surface of a flat support tray and accommodating the substrate in an internal space of a chamber;
supplying the processing fluid into the internal space and processing the substrate with the processing fluid in a supercritical state;
In the substrate processing method, the support tray supports the substrate, the upper surface of which is covered with a liquid film, in a state inclined at a predetermined angle from a horizontal position. The substrate processing method according to claim 12, wherein the processing fluid is introduced into the internal space in a gaseous or liquid state and is converted to a supercritical state within the internal space. 14. The substrate processing method according to claim 12, wherein the processing fluid is carbon dioxide, and the liquid constituting the liquid film is an organic solvent.

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