Substrate processing apparatus and substrate processing method

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

Technical Field

[0001] The present invention relates to a substrate processing apparatus and a substrate processing method for processing a substrate with a liquid adhered thereto by a processing fluid in a supercritical state.

Background Art

[0002] When a substrate is wet-processed with a liquid, the liquid adheres to the upper 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 depression is provided in a flat support tray, and in the depression, the substrate is supported in a horizontal posture with a minute gap between the upper surface of the support tray. In this state, the support tray is carried into a processing chamber, and the substrate is processed (supercritical processing) by filling the inside of the chamber with a processing fluid in a supercritical state. The substrate may be carried into the processing chamber in a state where its surface is covered with a liquid film in order to prevent the exposure of the surface and, when a fine pattern is formed on the surface, to prevent its collapse.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is assumed that the liquid constituting the liquid film covering the substrate at the time of loading is replaced by the processing fluid and removed from the substrate surface. However, if a part of the liquid enters the narrow gap between the lower surface of the substrate and the upper surface of the support tray, the replacement by the processing fluid does not proceed sufficiently, and as a result, the liquid may remain in the chamber and re-adhere to the substrate even at the final stage of the processing.

[0005] Therefore, in the initial stages of supercritical fluid processing, it is necessary to more efficiently remove the liquid that forms the liquid film from the substrate. In this respect, it can be said that there is still room for improvement in the conventional technology described above.

[0006] This invention has been made in view of the above-mentioned problems, and aims to provide 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 the processing fluid. [Means for solving the problem]

[0007] One aspect of the present invention is a substrate processing apparatus for processing a substrate with a supercritical processing fluid, comprising: a support tray having a flat plate shape and supporting the substrate placed on a substrate mounting surface on its upper surface; a chamber having an internal space capable of housing the support tray that supports the substrate; and a fluid supply unit for supplying the processing fluid to the internal space, wherein the support tray supports the substrate, whose upper surface is covered with a liquid film, in a state tilted at a predetermined angle from a horizontal position. In the first embodiment, the substrate mounting surface is provided with discharge guide portions that guide the liquid forming the liquid film and falling from the substrate from the substrate mounting surface to below the support tray. In the second embodiment, the substrate is supported such that, in a top view, at least a portion of the peripheral edge of the substrate protrudes outward from the outer edge of the support tray, and the substrate is tilted toward the protruding peripheral edge.

[0008] Another aspect of the present invention is a substrate processing method comprising the steps of: placing a substrate having a liquid film formed on its upper surface on the upper surface of a flat support tray and housing it in the internal space of a chamber; and supplying the processing fluid into the internal space to process the substrate with the processing fluid in a supercritical state, wherein the support tray supports the substrate, with its upper surface covered by a liquid film, at a predetermined angle tilted from a horizontal position. In the first embodiment, the liquid that constitutes the liquid film and falls from the substrate is guided from the substrate mounting surface to below the support tray via a discharge guide portion provided on the substrate mounting surface. In the second embodiment, the support tray supports the substrate in a state where, in a top view, at least a portion of the peripheral edge of the substrate protrudes outward from the outer edge of the support tray, and the substrate is tilted at a predetermined angle from a horizontal position so that it is tilted toward the protruding peripheral edge.

[0009] In supercritical fluid processing, which uses a supercritical fluid, the internal pressure of the chamber changes significantly, from atmospheric pressure immediately after the substrate is introduced to a high-pressure supercritical state as the fluid is introduced. During this process, as the fluid gradually dissolves into the liquid film on the substrate and the pressure increases, the fluidity of the liquid constituting the film increases rapidly, to the point where it can no longer maintain the film. At this point, the liquid flows off the substrate all at once, but when the substrate is held in a horizontal position, it is impossible to predict where the liquid will begin to fall. As a result, the fallen liquid may not be removed from the support tray and may seep into the gap between the substrate and the support tray.

[0010] In contrast, in the invention configured as described above, since the substrate is held in an inclined position within the chamber, the direction and location of the liquid flowing 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 the predicted location of liquid fall. By doing so, it is 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 set to be small enough to maintain a liquid film on the substrate under normal pressure. [Effects of the Invention]

[0011] As described above, in this invention, by supporting the substrate in a tilted position from a horizontal position within the chamber, it is possible to predict the direction and position of the liquid that maintains a liquid film under normal pressure as it flows off the substrate during the processing process. Therefore, it is possible to properly discharge the liquid that flows off the substrate and prevent it from re-adhering to the substrate. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows the overall configuration of a substrate processing apparatus to which the present invention can be applied. [Figure 2] This figure shows a first embodiment of the support tray. [Figure 3] This figure shows how the substrate is supported by the support tray in the first embodiment. [Figure 4] This figure shows the dimensional relationships in the substrate support by the support tray of the first embodiment. [Figure 5] This figure shows the support configuration of the substrate by the support tray in the second embodiment. [Figure 6] This figure shows the support configuration of the substrate by the support tray according to the third embodiment. [Figure 7] This figure shows the support configuration of the substrate by the support tray in the fourth embodiment. [Figure 8] This figure shows the support configuration of the substrate by the support tray according to the fifth embodiment. [Modes for carrying out the invention]

[0013] The following describes several embodiments of the substrate processing apparatus according to the present invention. Although the structure of the support tray, which will be described later, differs slightly between each embodiment, the basic apparatus configuration is common. Therefore, the overall configuration of the substrate processing apparatus will be described first, and then the characteristic parts of each embodiment will be explained separately.

[0014] <Overall configuration of the device> Figure 1 shows the overall configuration of a substrate processing apparatus to which the present invention can be applied. This substrate processing apparatus 1 is a device for processing the upper surface of various substrates, such as semiconductor substrates, with a supercritical fluid. For example, this substrate processing apparatus 1 can perform a supercritical drying process in which the liquid adhering to the substrate is replaced with a supercritical processing fluid to dry the substrate. In order to consistently show the directions in each of the following figures, an XYZ Cartesian coordinate system is set up as shown in Figure 1. Here, the XY plane is the horizontal plane, and the Z direction represents the vertical direction. More specifically, the (-Z) direction represents the vertically downward direction.

[0015] Here, as the "substrate" in the present embodiment, various substrates such as semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FED (Field Emission Display), substrates for optical discs, substrates for magnetic discs, and substrates for magneto-optical discs can be applied. In the following, a substrate processing apparatus mainly used for processing semiconductor wafers will be taken as an example and described with reference to the drawings, but it can be similarly applied to the processing of various substrates exemplified above.

[0016] The substrate processing apparatus 1 includes a processing unit 10, a transfer unit 30, a supply unit 50, and a control unit 90. The processing unit 10 is the main body for performing supercritical drying processing. The transfer unit 30 receives an unprocessed substrate conveyed by an external transfer device (not shown) and transfers it into the processing unit 10, and also delivers the processed substrate from the processing unit 10 to the external transfer device. The supply unit 50 supplies chemicals and power necessary for processing to the processing unit 10 and the transfer mechanism 30.

[0017] The control unit 90 controls each part of these devices to realize a predetermined process. For this purpose, the control unit 90 includes 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 operations of the devices described later are realized by the CPU 91 executing the control programs written in the storage 93 in advance and causing each part of the device to perform predetermined operations.

[0018] The processing unit 10 has a structure in which a processing chamber 12 is attached on a pedestal 11. The processing chamber 12 is composed of a combination of several metal blocks, and its interior is a cavity that forms a processing space SP. The substrate S to be processed is carried into the processing space SP and undergoes processing. On the (-Y)-side surface of the processing chamber 12, a slit-shaped opening 121 that extends elongated in the X direction is formed, and the processing space SP and the external space communicate with each other through the opening 121.

[0019] 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 in a horizontal posture on the (+Y)-side surface of the lid member 13, and the upper surface of the support tray 15 is 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.

[0020] The lid member 13 is movable forward and backward with respect to the processing chamber 12 by a forward and backward mechanism 53 provided in the supply unit 50. Specifically, the forward and backward 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. The forward and backward mechanism 53 operates in response to a control command from the control unit 90.

[0021] As shown by the dotted line in FIG. 1, when the lid member 13 moves in the (-Y) direction and the support tray 15 is pulled out from the processing space SP to the outside through the opening 121, access to the support tray 15 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, when the lid member 13 moves in the (+Y) direction, as shown by the solid line in FIG. 1, the support tray 15 is housed in the processing space SP. 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.

[0022] The lid member 13 moves in the (+Y) direction and closes the opening 121, thereby sealing the processing space SP. Although not shown in the figures, a sealing member is provided between the (+Y) side of the lid member 13 and the (-Y) side of the processing chamber 12 to maintain the airtight state of the processing space SP. Furthermore, the lid member 13 is fixed to the processing chamber 12 by a locking mechanism (not shown). With the processing space SP thus airtight, processing of the substrate S is performed within the processing space SP.

[0023] In supercritical drying, which primarily aims 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 by a liquid film to prevent the upper surface Sa from being exposed and causing pattern collapse. Suitable liquids for the liquid film include organic solvents with relatively low surface tension, such as isopropyl alcohol (IPA) and acetone.

[0024] In this embodiment, a fluid of a substance usable for supercritical processing, such as carbon dioxide, is supplied to the processing unit 10 in gaseous or liquid form from a fluid supply unit 57 provided in the supply unit 50. Carbon dioxide is a suitable chemical substance for supercritical drying processing because it becomes supercritical at relatively low temperatures and pressures, and also has the property of readily dissolving organic solvents that are frequently used in substrate processing.

[0025] 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. In this way, the substrate S is processed by the supercritical fluid in the processing chamber 12. The supply unit 50 is equipped with a fluid recovery unit 55, and the fluid after processing is recovered by the fluid recovery unit 55. The fluid supply unit 57 and the fluid recovery unit 55 are controlled by the control unit 90.

[0026] The transfer unit 30 is responsible for transferring the substrate S between the external transport device and the support tray 15. For this purpose, the transfer unit 30 comprises a main body 31, a lifting member 33, a base member 35, and multiple lift pins 37, each of which are provided. 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 movable in the Z direction.

[0027] A base member 35 having a substantially horizontal upper surface is attached to the upper part of the lifting member 33, and a plurality 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 its upper end contacting the lower surface of the substrate S. To stably support the substrate S, it is desirable to provide three or more lift pins 37 whose upper end heights are equal to each other.

[0028] The lifting member 33 is controlled by a lifting control unit 51 located in the supply unit 50, allowing it to move up and down. Specifically, the main body 31 of the transfer unit 30 is equipped with linear motion mechanisms (not shown), such as a linear motor, linear guide, ball screw mechanism, solenoid, or air cylinder. These linear motion mechanisms are 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 control commands from the control unit 90.

[0029] The base member 35 moves up and down as the lifting member 33 moves up and down, and multiple lift pins 37 move up and down in conjunction with it. This enables the transfer of the substrate S between the transfer unit 30 and the support tray 15. Specifically, it is as follows.

[0030] 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, when the support tray 15 is pulled out of the processing chamber 12, a through hole is formed at a position corresponding to directly above each lift pin 37. When the base member 35 rises due to the raising and lowering of the lifting member 33, the lift pins 37 pass through the through holes in the support tray 15 and reach a position where their tips are higher than the upper surface of the support tray 15. In this state, an unprocessed substrate S, transported by an external transport means, such as a transport robot with a hand capable of holding substrates, is handed over to the lift pins 37.

[0031] As the lift pins 37 supporting the substrate S descend, the substrate S also descends. Once the substrate S is in contact with the upper surface of the support tray 15, the lift pins 37 descend further, transferring the substrate S from the lift pins 37 to the support tray 15, where it is supported. In this way, the substrate S is loaded into the substrate processing apparatus 1. Finally, the lift pins 37 descend to a position where they do not interfere with the opening and closing operation of the lid member 13.

[0032] The unloading of the processed substrate S from the substrate processing apparatus 1 is achieved by the reverse operation described above. That is, with the substrate S supported on the support tray 15, the lift pin 37 rises, lifting the substrate S. The hand of the transport robot is then inserted between the bottom surface of the substrate S and the top surface of the support tray 15, allowing the substrate S to be transferred from the lift pin 37 to the transport robot.

[0033] As described above, the substrate processing apparatus 1 performs supercritical drying on the substrate S. The sequence of this process is as follows: First, the substrate S, whose top surface Sa is covered with a liquid film, is brought in from the outside and placed on the support tray 15. The support tray 15 enters the internal space SP of the processing chamber 12, and the substrate S is housed in the internal space SP. Then, with the internal space SP closed by the lid member 13, a gaseous or liquid processing fluid is introduced into the internal space SP from the fluid supply unit 57. The processing fluid is pressurized in the internal space SP and becomes supercritical, thereby replacing the liquid on the substrate S with the supercritical processing fluid. By continuing to supply the processing fluid from the fluid supply unit 57 and discharge it by the fluid recovery unit 55 for a certain period of time, the liquid that has separated from the substrate S is discharged. Finally, the processing fluid undergoes a phase transition from the supercritical state to the gas phase without passing through the liquid phase and is discharged, resulting in a dry state for the substrate S.

[0034] Next, several embodiments (support trays 151 to 155) of the support tray 1 in the substrate processing apparatus 1 described above will be explained. Although the structure of the support tray differs among the embodiments, they are common in other respects, and their operation is as described above. In the following descriptions of each embodiment, common or similar reference numerals will be used for components with common or similar structures and functions, and their descriptions will not be repeated. In addition, reference numerals may be omitted in some drawings for components where the correspondence between them is clear.

[0035] <First Embodiment> Figure 2 shows a first embodiment of the support tray. As shown in Figure 2(a), the support tray 151 of the first embodiment has a general shape in which a recess 1512 is provided on the horizontal and flat upper surface 1511 of a flat plate-shaped body 1510, corresponding to the planar size of the substrate S, more specifically having a diameter slightly larger than the diameter of the circular substrate S. The bottom surface 1513 of the recess 1512 is a horizontal plane.

[0036] Furthermore, the recess 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 cut-out portion 1515, a part of the bottom surface 1513 of the recess 1512 is directly connected to the side surface 1514. In this example, such cut-outs 1515 are provided at both ends on the X side and the (+Y) side of the support tray 151, and in these areas, the bottom surface 1513 is directly connected to the side surface 1514.

[0037] Furthermore, a through hole 1514 is drilled in the bottom surface 1513 at a position corresponding to the lift pin 37 of the transfer unit 30 for inserting the lift pin 37. As the lift pin 37 moves up and down through the through hole 1514, the substrate S can be positioned in the recess 1512 and lifted above it.

[0038] Multiple support pins 16 are arranged around the periphery of the recess 1512. The number of support pins 16 can be arbitrary, but it is desirable to have three or more in order to stably support the substrate S. As shown in Figures 2(b) and 2(c), the support pins 16 have a height-restricting portion 161 and a horizontal position-restricting portion 162.

[0039] The height-regulating portion 161 has a flat upper surface and supports the substrate S by contacting the peripheral edge of the lower surface Sb of the substrate S, thereby regulating its position in the height direction (Z direction). On the other hand, the horizontal position-regulating portion 162 extends above the upper end of the height-regulating portion 161 and controls the horizontal position of the substrate S by contacting the side surface of the substrate S. With these support pins 16, the substrate S is supported in a predetermined position within the recess 1512, while maintaining a predetermined gap from the bottom surface 1513.

[0040] Figure 3 shows the support configuration of the substrate by the support tray in the first embodiment. As shown in the top view of Figure 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 restricted by the support pins 16a, 16b, and 16c. At this time, the substrate S is supported with a portion of it protruding to the (+Y) side beyond the (+Y) side end of the support tray 151.

[0041] Furthermore, the support pin 16a located furthest to the (-Y) side supports the substrate S at a higher position than the other support pins 16b and 16c. That is, the height restriction portion 161a of support pin 16a is located higher than the height restriction portions 161b and 161c of the other two support pins 16b and 16c. Therefore, as shown in Figure 3(b), the substrate S is supported in an inclined state with a downward slope in the (+Y) direction. The dashed arrows in Figures 3(a) and 3(b) indicate the inclination direction of the substrate S.

[0042] The substrate S, which is introduced into the processing space SP of the processing chamber 12, has its upper surface Sa covered with a liquid film LF. The liquid constituting the liquid film LF is an organic solvent such as IPA. As will be described later, the tilt of the substrate S is small enough that the liquid film LF is maintained by its surface tension even when the substrate S is introduced into the processing space SP under atmospheric pressure. Therefore, as shown in Figure 3(b), the substrate S remains covered with the liquid film LP on its upper surface Sa even within the processing space SP. From this state, the processing fluid is introduced into the processing space SP.

[0043] During the process in which the processing fluid is introduced into the processing space SP and eventually pressurized to a supercritical state, a portion of the processing fluid dissolves into the liquid film LF. Consequently, the viscosity of the liquid constituting 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 breaks down and the liquid flows rapidly off the substrate S. In Figure 3(c), the symbol F indicates the processing fluid filling the processing space SP.

[0044] In this configuration, the substrate S is tilted in the (+Y) direction, and its (+Y) side end protrudes beyond the end of the support tray 151. As a result, the liquid that flows down does not adhere to the support tray 151, but flows directly down to the bottom of the processing space SP. The flowing liquid is carried downstream, i.e., in the (-Y) direction, along with the processing fluid F, and is finally discharged from the processing space SP. This prevents the liquid from getting between the bottom 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.

[0045] Figure 4 shows the dimensional relationships in the substrate support by the support tray of the first embodiment. As shown in Figure 4(a), the sign θ represents the inclination of the normal to the upper surface Sa of the substrate, indicated by the dashed line, with respect to the vertical axis (Z axis), the sign G represents the minimum gap between the lower surface Sb of the substrate S and the upper surface of the support tray 151 (more specifically, the bottom surface 1513 of the recess 1512), and the sign P represents the amount of protrusion of the substrate S from the support tray 151 at the (+Y) side end. Here, the inclination angle θ of the substrate S is expressed as the inclination of the normal to the vertical axis, which is technically equivalent to the inclination of the upper surface Sa with respect to the horizontal plane.

[0046] The upper limit of the inclination angle θ is constrained by conditions such as the ability to maintain the liquid film LF on the substrate S under atmospheric pressure, the ability to avoid hindering the loading into and unloading of the processing space SP, and the ability to avoid obstructing the flow of the processing fluid within the processing space SP. Considering these conditions, the inventors of this application have found that it is desirable to set the inclination angle θ to, for example, 5 degrees or less.

[0047] On the other hand, the lower limit of the inclination angle θ can be considered as follows: In a high-pressure environment close to 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 of liquid flow is determined by a very slight inclination of the substrate S. Thus, in principle, the inclination angle θ can be any magnitude greater than zero.

[0048] However, considering the installation environment of this type of substrate processing apparatus 1, even if sufficient adjustments are made during installation, it is unavoidable that some degree of tilt will remain. In the inventor's knowledge, the maximum tilt of the apparatus in a well-adjusted state is about 0.5 degrees. Therefore, even if the apparatus body has such a tilt, it is desirable to set the tilt angle θ to be greater than the maximum tilt angle of the apparatus body (0.5 degrees) in order to tilt the substrate S in the desired direction. In order to ensure a significant tilt even in such cases, the tilt angle θ can be set to, for example, 1 degree or more. Therefore, the appropriate range for the tilt angle θ can be greater than 0.5 degrees and 5 degrees or less, more preferably between 1 degree and 5 degrees.

[0049] The amount P that the substrate S protrudes from the support tray 151 should be greater than or equal to zero, more preferably greater than zero, in order to allow the flowing liquid to fall directly. However, it is possible to substantially eliminate liquid residue even without providing such a protrusion. 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 some of the liquid flowing down from the substrate S adheres to the bottom surface 1513 of the recess 1512, it is expected to be discharged from this connection during the processing. To further enhance this effect, the bottom surface 1513 may be partially inclined toward the connection with the side surface.

[0050] Furthermore, it is preferable that the minimum gap G between the substrate S and the support tray 151 is greater than 0.5 mm. In the inventors' knowledge, when the gap is 0.5 mm or less, as shown in Figure 4(b), the liquid Lq that formed the liquid film is more likely to flow around to the lower surface Sb of the substrate S by capillary action and remain and adhere to the gap with the support tray 151.

[0051] While the supercritical processing fluid dissolves 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 is possible, it would take a long time. The residue of 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 re-adhesion to the substrate S. By making the minimum gap G larger than 0.5 mm, it is possible to effectively suppress such liquid leakage.

[0052] Conventional technology assumes that the substrate is held in a horizontal position. However, in reality, the entire device may be slightly tilted, or the top surface of the support tray may be tilted within the tolerances of the processing and assembly of each component. As a result, when the viscosity of the liquid decreases under high pressure, it is not possible to control the direction in which the liquid flows down, nor is it reproducible. The liquid that leaks out in this way ends up getting between the substrate and the support tray.

[0053] In contrast, in this embodiment, it is possible to tilt the substrate S in a desired direction, taking into account the tilt of such a device, thereby controlling the direction and position in which the liquid flows down when the liquid film on the substrate S breaks. Therefore, by providing means for discharging the flowing liquid at that position, it is possible to prevent the liquid from flowing back. In this embodiment, by making the edge of the substrate S in the direction in which the liquid flows down protrude beyond the support tray 151, the liquid can be made to fall directly downward without contacting the support tray 151.

[0054] The concepts of the inclination angle θ, minimum gap G, and overhang amount P described here are also applicable to each embodiment described below.

[0055] <Second Embodiment> Figure 5 shows the support configuration of the substrate by the support tray in the second embodiment. More specifically, Figure 5(a) is a diagram showing the external appearance of the support tray 152 in the second embodiment, and Figure 5(b) is a cross-sectional view thereof along line AA. In this embodiment, the support pin 16b provided near the (-X) side 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. Note that the two support pins 16a and 16c may support the substrate S at the same height. Alternatively, 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.

[0056] 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 will flow down from the (+X) side edge of the substrate S. In this case as well, as shown in Figure 5(b), a notch 1526 is provided at the (+X) side edge of the support tray 152, and the substrate S protrudes further than the support tray 152, which makes it possible to more effectively suppress the leakage of liquid to the lower surface Sb of the substrate. On the other hand, a notch is not necessary at the (+Y) side edge of the support tray 152.

[0057] In this embodiment, the substrate S is tilted towards the (+X) side, but it is equivalent to tilting it towards the (-X) side. In this case, the support pin 16c near the (+X) end of the support tray 152 should be positioned higher than the other support pins 16a and 16b to support the substrate S.

[0058] <Third Embodiment> Figure 6 shows the support configuration of the substrate by the support tray in the third embodiment. In the support tray 153 of this embodiment, of the three support pins 16a, 16b, and 16c, the support pin 16a, which is closest to (-Y), is configured to support the substrate S at a relatively lower position than the other support pins 16b and 16c. Therefore, the substrate S is supported in an inclined state with a downward slope toward the (-Y) side. As a result, the liquid on the substrate S flows in the (-Y) direction and flows down from the (-Y) side end of the substrate S onto the upper surface 1531 of the support tray 153.

[0059] To prevent this liquid from flowing to the underside of the substrate S, the upper surface 1531 of the support tray 153 has been modified by eliminating the step required to form a recess, and is further provided with a slope that descends in the (-X) and (+X) directions. The liquid that flows from the substrate S to the support tray 153 flows down along this sloped surface 1531 and falls downward from the (-X) and (+X) end faces of the support tray 153. This prevents the liquid from entering between the substrate S and the support tray 153.

[0060] 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 inclination of the upper surface 1531 is designed to guide the liquid flowing down from the substrate S toward this through hole 1537. With this configuration, the liquid that flows down onto the support tray 153 can be more efficiently allowed to fall downwards, preventing it from remaining on the upper surface 1531 of the support tray 153.

[0061] In the third embodiment and its modifications, the liquid on the substrate S flows downward in the (-Y) direction. As the liquid flows downward, the processing space SP is filled with processing fluid flowing in the (-Y) direction. Therefore, the liquid that has separated from the substrate S is carried further in the (-Y) direction along this flow and discharged, that is, away from the substrate S. Consequently, the probability of the liquid re-adhering to the substrate S can be reduced compared to when the liquid flows downward in the (+Y) direction.

[0062] <Fourth Embodiment> Figure 7 shows the support configuration of the substrate by the support tray in the fourth embodiment. In each of the above embodiments, the substrate S is supported in an inclined state on the support tray 15 by making the substrate support heights of each 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 upper surface 1541 an inclined surface, it is possible to support the substrate S in an inclined state even if each support pin 16 has the same structure.

[0063] In this example, as shown by the dashed arrows in Figures 7(a) and 7(b), the bottom surface 1543 of the recess 1542 is shaped to be inclined toward the (+Y) direction. This structure also allows the liquid on the substrate S to flow downward in the (+Y) direction and fall downward from the (+Y) side edge of the substrate S. Furthermore, even if the liquid flows around to the underside of the substrate S, the upper surface of the support tray 154 itself is inclined, so the liquid can be expected to flow downward along the direction of the inclination.

[0064] <Fifth Embodiment> Figure 8 shows the support configuration of the substrate by the support tray in the fifth embodiment. In this embodiment, unlike the fourth embodiment, the upper surface 1551 of the support tray 155 is an inclined surface that slopes downward in the (-Y) direction. Therefore, the liquid on the substrate S flows in the (-Y) direction and flows down onto the upper surface 1551 of the support tray 155. In this case as well, it is more desirable that the upper surface 1551 of the support tray 155 be provided with inclinations in the (-X) and (+X) directions. Through holes may also be provided to allow the liquid to fall.

[0065] <Other> As described 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 function as the "chamber" and "lid member" of the present invention, respectively. In addition, the support pin 16 functions as the "support part" of the present invention. Furthermore, the processing space SP corresponds to the "internal space" of the present invention.

[0066] Furthermore, 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 "discharge guide portion" of the present invention. Furthermore, in the support tray 153 of the third embodiment and its modified example 153a, the inclined surface 1531 and the through hole 1537 correspond to the "discharge guide portion" of the present invention.

[0067] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made to those described above without departing from the spirit of the invention. For example, in each of the above embodiments, the substrate S is supported by support pins 16 provided on the upper surface of the support tray 15, so as to be spaced apart from the upper surface of the support tray 15. However, instead of installing support pins 16, the substrate may be supported by a projection provided on the upper surface of the support tray. In this case, the projection would correspond to the "support part" of the present invention.

[0068] Furthermore, 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 drainage from the through holes cannot be expected, liquid residue is more likely to occur, and therefore the liquid residue prevention effect of the present invention is considered to function more effectively. Similarly, the present invention functions effectively regardless of whether or not the support tray has recesses for accommodating substrates.

[0069] Furthermore, the various chemical substances in the above embodiments, such as IPA and carbon dioxide, are listed as representative examples of substances that may be used, and this does not mean that the application of the present invention is limited to technologies using these substances.

[0070] As described above with examples of specific embodiments, in the present invention, the support tray can support the substrate such that, in a top view, at least a portion of the peripheral edge of the substrate protrudes outward from the outer edge of the support tray, and the substrate is tilted toward the protruding peripheral edge. With this configuration, liquid flowing down from the substrate can fall directly downward without coming into contact with the support tray, and liquid leakage between the substrate and the support tray can be effectively suppressed.

[0071] For example, the substrate mounting surface may be provided with discharge guide sections that guide the liquid, which forms a liquid film and drips from the substrate, downward from the substrate mounting surface to below the support tray. If it is unavoidable that the liquid flowing down from the substrate will adhere to the substrate mounting surface, providing such discharge guide sections can facilitate the discharge of the liquid from the substrate mounting surface.

[0072] Specifically, for example, the upper surface of the support tray is provided with a recess that is set back downward and has a planar size capable of accommodating a substrate, the flat bottom surface of the recess forms the substrate mounting surface, and at least a portion of the bottom surface extends to the outer edge of the support tray and connects to the side surface of the support tray, and the support tray may support the substrate such that the substrate is tilted toward the portion of the peripheral edge located above the connection between the bottom surface and the side surface, in which case the connection portion forms the discharge guide portion.

[0073] For example, the discharge guide portion can be provided as a through-hole that penetrates from the substrate mounting surface to the underside of the support tray. With such a configuration, liquid adhering to the substrate mounting surface can be guided to the through-hole, thereby promoting rapid discharge.

[0074] For example, the discharge guide section can also be provided as an inclined surface with a downward slope from the substrate mounting surface toward the side of the support tray. With such a configuration, liquid adhering to the substrate mounting surface can flow down along the inclined surface, promoting rapid discharge.

[0075] Furthermore, the substrate mounting surface itself may be inclined with respect to the horizontal plane. With such a configuration, the substrate can be supported in an inclined state by placing it parallel to the substrate mounting surface. In addition, any attached liquid can be allowed to flow down along the inclined surface, preventing it from remaining on the substrate mounting surface.

[0076] For example, the support tray may be provided with multiple support parts that partially contact the lower surface of the substrate, supporting the substrate in a state where it is spaced upward from the upper surface of the support tray. With such a configuration, it becomes possible to stably support the substrate while maintaining a predetermined gap between the lower surface of the substrate and the upper surface of the support tray.

[0077] In this case, the height of at least one of the support parts from the substrate mounting surface may differ from that of the other support parts. With such a configuration, the substrate can be supported at an angle by varying the heights of the support parts.

[0078] Furthermore, the processing fluid may be introduced into the internal space in gaseous or liquid form and converted to a supercritical state within the internal space. With such a configuration, during the process of pressurizing the substrate, which has a liquid film formed on it, from its state of being housed in the internal space to reaching a supercritical state, the viscosity of the liquid forming the liquid film decreases, and a moment occurs when it flows rapidly down from the substrate. By causing the liquid to flow down rapidly in this way, it becomes possible to suppress the residue of the liquid.

[0079] For example, the processing fluid may be carbon dioxide, and the liquid constituting the liquid film may be an organic solvent. Carbon dioxide transitions to a supercritical state at relatively low temperatures and pressures compared to other chemical substances, making it suitably applicable to this type of processing. Furthermore, since carbon dioxide dissolves organic solvents well, it is particularly effective as a processing fluid used for the purpose of replacing them.

[0080] Furthermore, 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 to connect the internal space and the external space, and the apparatus further comprises a lid member that closes the opening and a reciprocating mechanism that moves the lid member forward and backward relative to the opening, and a support tray is integrally coupled with the lid member, and the support tray is housed in the internal space when the lid member closes the opening. With such a configuration, the support tray can be moved in and out of the chamber by the reciprocating of the lid member, and since the lid member is robustly constructed to close the chamber where the internal space becomes high pressure, it is possible to firmly support the support tray.

[0081] In this invention, the "predetermined angle" can be, for example, an angle greater than 0.5 degrees and less than 5 degrees. According to the inventors' knowledge, the inclination angle of the substrate that can maintain a liquid film on the substrate under normal pressure, control the direction of liquid flow under high pressure, and is not affected by the inclination of the apparatus body can be greater than 0.5 degrees and 5 degrees or less, and more preferably 1 degree or more and less than 5 degrees. [Industrial applicability]

[0082] This invention can be applied to all substrate processing technologies that involve processing a substrate with liquid adhering to its surface using a supercritical processing fluid. [Explanation of symbols]

[0083] 1. Substrate processing apparatus 12 Processing Chamber (Chamber) 13 Lid member 15 Support tray 16. Support pin (support part) 53 Advancement / retraction mechanism 57 Fluid supply section 121 Aperture 1513 Recess (Substrate mounting surface) 1516 Notch (discharge guide area) 1531 Inclined surface (discharge guide part) 1537 Through-hole (discharge guide area) F Processing fluid LF liquid film S substrate SP processing space (internal space)

Claims

1. In a substrate processing apparatus that processes a substrate using a processing fluid in a supercritical state, A support tray having a flat plate shape, which supports the substrate placed on the substrate mounting surface on its upper surface, 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 Equipped with, The support tray supports the substrate, whose upper surface is covered with a liquid film, in a state tilted at a predetermined angle from a horizontal position. A substrate processing apparatus, wherein the substrate mounting surface is provided with a discharge guide portion that guides the liquid forming the liquid film and falling from the substrate downward from the substrate mounting surface to the support tray.

2. A substrate processing apparatus for processing a substrate with a processing fluid in a supercritical state, A support tray having a flat plate shape, which supports the substrate placed on the substrate mounting surface on its upper surface, 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 Equipped with, A substrate processing apparatus, wherein the support tray supports the substrate, whose upper surface is covered with a liquid film, in a state where, when viewed from above, at least a portion of the peripheral edge of the substrate protrudes outward from the outer edge of the support tray, and the substrate is tilted at a predetermined angle from a horizontal position so that it is tilted toward the protruding peripheral edge.

3. The upper surface of the support tray is provided with a recess that is recessed downward and has a planar size capable of accommodating the substrate, the flat bottom surface of the recess forms the substrate mounting surface, and at least a portion of the bottom surface extends to the outer edge of the support tray and connects to the side surface of the support tray. The substrate processing apparatus according to claim 1, wherein the support tray supports the substrate such that the substrate is tilted toward a portion of the substrate located above the connection portion between the bottom surface and the side surface, and the connection portion forms the discharge guide portion.

4. The substrate processing apparatus according to claim 1, wherein the discharge guide portion is a through hole that penetrates from the substrate mounting surface to the lower surface of the support tray.

5. The substrate processing apparatus according to claim 1, wherein the discharge guide portion is an inclined surface having a downward slope from the substrate mounting surface toward the side surface of the support tray.

6. The substrate processing apparatus according to claim 1 or 2, wherein the substrate mounting surface is inclined with respect to a horizontal plane.

7. The substrate processing apparatus according to any one of claims 1 to 5, wherein the support tray is provided with a plurality of support portions that partially contact the lower surface of the substrate and support the substrate in a state where it is spaced upward away from the upper surface of the support tray.

8. The substrate processing apparatus according to claim 7, wherein at least one of the plurality of support portions has a height from the substrate mounting surface that is different from that of the other support portions.

9. An opening is provided on the side of the chamber to connect the internal space and the external space. The system further comprises a lid member that closes the opening, and a reciprocating mechanism that moves the lid member forward and backward relative to the opening. The substrate processing apparatus according to any one of claims 1 to 5, wherein the support tray is integrally coupled with the lid member, and when the lid member closes the opening, the support tray is housed in the internal space.

10. The substrate processing apparatus according to any one of claims 1 to 5, wherein the predetermined angle is greater than 0.5 degrees and less than 5 degrees.

11. A step of placing a substrate on which a liquid film has been formed on its upper surface onto the substrate mounting surface on the upper surface of a flat support tray and housing it in the internal space of the chamber, A step of supplying a processing fluid to the internal space and processing the substrate with the processing fluid in a supercritical state. Equipped with, The support tray supports the substrate, whose upper surface is covered with a liquid film, in a state tilted at a predetermined angle from a horizontal position. A substrate processing method comprising guiding the liquid that forms the liquid film and falls from the substrate from the substrate mounting surface to below the support tray via an discharge guide portion provided on the substrate mounting surface.

12. A step of placing a substrate on which a liquid film has been formed on its upper surface onto the upper surface of a flat support tray and housing it in the internal space of a chamber, A step of supplying a processing fluid to the internal space and processing the substrate with the processing fluid in a supercritical state. Equipped with, A substrate processing method comprising: a support tray supporting the substrate, whose upper surface is covered with a liquid film, in a state where, in a top view, at least a portion of the peripheral edge of the substrate protrudes outward from the outer edge of the support tray, and the substrate is tilted at a predetermined angle from a horizontal position so that it is tilted toward the protruding peripheral edge.

13. The substrate processing method according to claim 11 or 12, wherein the processing fluid is introduced into the internal space in a gaseous or liquid state and converted to a supercritical state within the internal space.

14. The substrate processing method according to claim 11 or 12, wherein the processing fluid is carbon dioxide and the liquid constituting the liquid film is an organic solvent.

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