Substrate processing equipment

Abstract

To effectively prevent the adhesion of contaminants and pattern collapse, which tend to occur in the center of a substrate in a substrate processing technology that processes a substrate with processing fluid in a processing space of a processing container.SOLUTION: A substrate processing apparatus includes, in an upper discharge flow path that discharges a processing fluid that has passed above and below the substrate individually, and discharges the processing fluid that has passed above the substrate, an upstream portion that communicates with a processing space above the substrate, a buffer space that communicates with the upstream portion and has a larger cross-sectional area of the flow path than the upstream portion, a downstream portion that connects a pair of openings provided at both ends of the buffer space and a fluid discharge portion, and a rectifying portion that is provided at the connection between the upstream portion and the buffer space and makes the pressure loss in the center lower than the pressure loss at both ends.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This invention relates to a substrate processing apparatus that processes a substrate with a processing fluid in a processing vessel.

Background Art

[0002] Processing steps for various substrates such as semiconductor substrates and glass substrates for display devices include those that process the surface of the substrate with various processing fluids. Processing using liquids such as chemical solutions and rinse liquids as the processing fluid has been widely performed conventionally, but in recent years, processing using supercritical fluids has also been put into practical use. In particular, in the processing of substrates having fine patterns formed on their surfaces, supercritical fluids with lower surface tension than liquids can enter deep into the gaps between the patterns, enabling efficient processing, and also reducing the risk of pattern collapse caused by surface tension during drying.

[0003] For example, Patent Document 1 previously disclosed by the applicant of the present application describes a substrate processing apparatus that performs a drying process on a substrate using a supercritical fluid. In this Patent Document 1, the flow rate balance in the discharge flow path for discharging the processing fluid after processing the substrate in the processing vessel (high-pressure chamber) into which the processing fluid in the supercritical state is introduced is a problem. Specifically, it is proposed to provide a rectifying section in the discharge flow path because the balance between the amount of the processing fluid flowing into the discharge flow path and the amount of the processing fluid discharged from the discharge flow path is not achieved, causing backflow of the processing fluid, which leads to recontamination of the substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Patent Document 1 suggests that by providing a flow straightening section in the discharge channel, it may be possible to adjust the balance between the processed fluid flowing towards the straightening section and the processed fluid after it has passed through the straightening section. However, it does not describe in detail the specific problems and the configuration of the flow straightening section to solve them. For example, according to findings obtained by the present applicant after filing Patent Document 1, it has become clear that contamination of the substrate and collapse of the pattern caused by backflow of the processed fluid are particularly pronounced in the central part of the substrate in the width direction perpendicular to the flow direction of the processed fluid.

[0006] However, Patent Document 1 does not provide specific disclosures regarding these problems or the structure of a flow rectifier capable of solving them. In this respect, it can be said that there is room for improvement in the above-mentioned prior art.

[0007] This invention has been made in view of the above-mentioned problems, and aims to provide a technology that can effectively prevent the adhesion of contaminants and the collapse of patterns that tend to occur in the central part of a substrate. [Means for solving the problem]

[0008] One aspect of this invention is a substrate processing apparatus comprising: a flat support tray that supports a substrate placed on its upper surface in a horizontal position; a processing container having a processing space capable of accommodating the substrate together with the support tray; a fluid supply unit that supplies a processing fluid for supercritical processing to the processing space from one end of the processing space; and a fluid discharge unit that discharges the processing fluid via a discharge channel provided on the other end opposite to the one end of the substrate, communicating with the processing space. Here, when the direction parallel to the main surface of the substrate among the directions perpendicular to the flow direction of the processing fluid is defined as the first direction, and the direction perpendicular to the flow direction and the first direction is defined as the second direction, the discharge channels are provided to discharge the processing fluid that has passed over the substrate and the processing fluid that has passed below the support tray separately, and the upper discharge channel that discharges the processing fluid that has passed over the substrate has an upstream section that communicates with the processing space above the substrate and has a channel cross-section in which the opening dimension along the first direction is larger than the opening dimension along the second direction, a buffer space that communicates with the upstream section and has a channel cross-sectional area larger than that of the upstream section, a downstream section that connects the fluid discharge section to a pair of openings provided at both ends of the buffer space in the first direction, and a flow straightening section provided at the connection between the upstream section and the buffer space, which makes the pressure loss in the central section in the first direction lower than the pressure loss at both ends. In the rectifying section, the pressure loss of the discharge channel increases monotonically in a broad sense along the first direction from the central part toward both ends.

[0009] In this configuration, the flow straightening section provided in the discharge channel for the processed fluid is configured such that the pressure loss is low in the center of the discharge channel and high at both ends. As a result, the flow velocity and flow rate of the processed fluid flowing into the buffer space are higher in the center than at both ends. This creates a flow of processed fluid in the buffer space that moves from the center to both ends.

[0010] As will be explained in more detail later, the reason why contaminants tend to adhere to the center of the substrate is thought to be that the processing fluid that gets trapped between the substrate and the support tray does not drain properly, causing the contaminated processing fluid to accumulate around the substrate. Therefore, by controlling the flow of the processing fluid by creating a difference in pressure loss in the discharge channel as described above, it is possible to promote discharge from the center and prevent stagnation, thereby reducing processing defects such as the adhesion of contaminants and the collapse of patterns. [Effects of the Invention]

[0011] As described above, according to the present invention, by creating a difference in pressure loss between the central part and both ends of the discharge channel, the discharge of the processing fluid from the central part is promoted, thereby effectively preventing the adhesion of contaminants and pattern collapse that tend to occur in the central part of the substrate. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows a schematic configuration of a first embodiment of the substrate processing apparatus according to the present invention. [Figure 2] This is a schematic diagram showing the outline of the flow path of the processed fluid. [Figure 3] This is a schematic plan view showing the flow path of the processed fluid. [Figure 4] This is a side cross-sectional view showing the detailed structure of the discharge channel. [Figure 5] This diagram illustrates the structure around the opening of the processing chamber. [Figure 6] This diagram illustrates the structure around the opening of the processing chamber. [Figure 7] This diagram shows the flow of the processing fluid near the partition wall. [Figure 8] This figure illustrates the structure around the opening of the processing chamber in the second embodiment. [Figure 9] This diagram illustrates other configurations of the rectifier section. [Figure 10] This diagram illustrates other configurations of the rectifier section. [Modes for carrying out the invention]

[0013] FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a substrate processing apparatus according to the present invention. This substrate processing apparatus 1 is an apparatus for processing the surface of various substrates such as, for example, a semiconductor substrate with a supercritical fluid. In order to uniformly indicate the directions in the following figures, an XYZ orthogonal coordinate system is set as shown in FIG. 1. Here, the XY plane is a horizontal plane, and the Z direction represents the vertical direction. More specifically, the (-Z) direction represents vertically downward.

[0014] Here, as the "substrate" in the present embodiment, various substrates such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display, a glass substrate for a plasma display, a substrate for a FED (Field Emission Display), a substrate for an optical disk, a substrate for a magnetic disk, and a substrate for a magneto-optical disk can be applied. Hereinafter, a substrate processing apparatus mainly used for processing a semiconductor wafer 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.

[0015] The substrate processing apparatus 1 includes a processing unit 10, a supply unit 50, and a control unit 90. The processing unit 10 is the main body that executes supercritical drying processing, and the supply unit 50 supplies the chemical substances and power necessary for the processing to the processing unit 10.

[0016] The control unit 90 controls each part of these apparatuses 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 a user or an external device. The operations of the apparatuses described later are realized by the CPU 91 executing the control programs written in advance in the storage 93 and causing each part of the apparatus to perform a predetermined operation.

[0017] The processing unit 10 includes a processing chamber 100. The processing chamber 100 includes a first member 11, a second member 12, and a third member 13 each formed of a metal block. The first member 11 and the second member 12 are vertically coupled by a coupling member not shown, and the third member 13 is coupled to the (+Y) side surface thereof by a coupling member not shown, thereby constituting the processing chamber 100 having a structure with a cavity 110 inside. The internal space of this cavity 110 serves as a processing space SP where processing on the substrate S is performed. The substrate S to be processed is carried into the processing space SP and undergoes processing. A slit-shaped opening 101 extending elongated in the X direction is formed in the (-Y) side surface of the processing chamber 100, and the processing space SP and the external space communicate with each other through the opening 101.

[0018] A lid member 14 is provided on the (-Y) side surface of the processing chamber 100 so as to close the opening 101. A flat support tray 15 is horizontally attached to the (+Y) side surface of the lid member 14, and the upper surface of the support tray 15 serves as a support surface on which the substrate S can be placed. More specifically, the support tray 15 has a structure in which a recess 152 slightly larger than the planar size of the substrate S is provided on a substantially flat upper surface 151. By accommodating the substrate S in this recess 152, the substrate S is held at a predetermined position on the support tray 15. The substrate S is held with the surface to be processed (hereinafter sometimes simply referred to as the "substrate surface") Sa facing upward. At this time, it is preferable that the upper surface 151 of the support tray 15 and the substrate surface Sa form the same or substantially the same plane.

[0019] The lid member 14 is horizontally movably supported in the Y direction by a support mechanism (not shown). Further, the lid member 14 is movable forward and backward with respect to the processing chamber 100 by an advance / retreat mechanism 53 provided in the supply unit 50. Specifically, the advance / retreat mechanism 53 has a linear motion mechanism such as a linear motor, a linear guide, a ball screw mechanism, a solenoid, or an air cylinder, and such a linear motion mechanism moves the lid member 14 in the Y direction. The advance / retreat mechanism 53 operates in response to a control command from the control unit 90.

[0020] When the lid member 14 moves in the (-Y) direction, the support tray 15 is pulled out of the processing space SP through the opening 101, allowing access to the support tray 15 from the outside. That is, it becomes possible to place a substrate S on the support tray 15 and to remove a substrate S that is placed on the support tray 15. On the other hand, when the lid member 14 moves in the (+Y) direction, the support tray 15 is housed inside the processing space SP. If a substrate S is placed on the support tray 15, the substrate S is transported into the processing space SP together with the support tray 15.

[0021] 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 surface Sa covered by a liquid film to prevent the 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.

[0022] The lid member 14 moves in the (+Y) direction and closes the opening 101, thereby sealing the processing space SP. A sealing member 16 is provided between the (+Y) side surface of the lid member 14 and the (-Y) side surface of the processing chamber 100, maintaining the airtight state of the processing space SP. As the sealing member 16, an annular one made of an elastic resin material, such as rubber, can be used. In addition, the lid member 14 is fixed to the processing chamber 100 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 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.

[0024] More specifically, the fluid supply unit 57 outputs a supercritical fluid, or a fluid supplied in gaseous or liquid form that subsequently becomes supercritical when given a predetermined temperature and pressure, as a processing fluid for processing the substrate S. For example, gaseous or liquid carbon dioxide is output under pressure. The fluid is pumped through piping 571 and valves 572 and 573 inserted in the piping to input ports 102 and 103 provided on the (+Y) side of the processing chamber 100. That is, the fluid is sent from the fluid supply unit 57 to the processing chamber 100 when valves 572 and 573 are opened in response to a control command from the control unit 90.

[0025] Figures 2 and 3 schematically illustrate the flow path of the processed fluid. More specifically, Figure 2 is a schematic diagram showing the outline of the flow path, and Figure 3 is a plan view thereof. Figure 4 is a side cross-sectional view showing the detailed structure of the discharge flow path. The structure of the processed fluid flow path will be described below with reference to Figures 1 through 4.

[0026] The fluid channel 17 from input ports 102 and 103 to the processing space SP functions as an introduction channel for introducing the processing fluid supplied from the fluid supply unit 57 into the processing space SP. Specifically, a channel 171 is connected to input port 102. At the end of channel 171 opposite to input port 102, a buffer space 172 is provided, which is formed so that the cross-sectional area of ​​the channel expands rapidly.

[0027] A flow path 173 is further provided to connect the buffer space 172 and the processing space SP. The flow path 173 has a wide cross-sectional shape that is narrow in the vertical direction (Z direction) and long in the horizontal direction (X direction), and its cross-sectional shape is substantially constant in the direction of flow of the processing fluid. The end of the flow path 171 opposite to the buffer space 172 is an outlet 174 that opens facing the processing space SP, and the processing fluid is introduced into the processing space SP from this outlet 174.

[0028] Preferably, the height of the flow path 173 is equal to the distance between the ceiling surface 110a of the processing space SP and the substrate surface Sa when the support tray 15 is housed in the processing space SP. The discharge port 174 opens facing the gap between the ceiling surface 110a of the processing space SP and the upper surface 151 of the support tray 15. For example, the ceiling surface of the flow path 173 and the ceiling surface 110a of the processing space SP can be made to be on the same plane. In this way, the discharge port 174 opens in a horizontally elongated slit shape facing the processing space SP.

[0029] A fluid channel for the processing fluid is similarly formed below the support tray 15. Specifically, a channel 175 is connected to the input port 103. At the end of the channel 175 opposite to the input port 103, a buffer space 176 is provided, which is formed so that the cross-sectional area of ​​the channel expands rapidly.

[0030] The buffer space 176 and the processing space SP are connected via a flow path 177. The flow path 177 has a cross-sectional shape that is narrow in the vertical direction (Z direction) and wide in the horizontal direction (X direction), and its cross-sectional shape is substantially constant in the direction of flow of the processing fluid. The end of the flow path 177 opposite to the buffer space 176 is an outlet 178 that opens facing the processing space SP, and the processing fluid is introduced into the processing space SP from this outlet 178.

[0031] Preferably, the height of the flow path 177 is equal to the distance between the bottom surface 110b of the processing space SP and the bottom surface of the support tray 15. The discharge port 178 opens facing the gap between the bottom surface 110b of the processing space SP and the bottom surface of the support tray 15. For example, the bottom surface 110b of the flow path 177 and the bottom surface of the processing space SP can be made to be on the same plane. In other words, the discharge port 178 opens in a horizontally elongated slit shape facing the processing space SP.

[0032] In the Z direction, it is desirable that the positions of the flow path 171 and the flow path 173 are different. When they are at the same height, some of the processed fluid that flows from flow path 171 into buffer space 172 will continue straight into flow path 173. In this case, in the width direction of the flow path perpendicular to the flow direction, i.e., in the X direction, there is a risk that differences will occur in the flow rate and velocity of the processed fluid flowing into flow path 173 between the position corresponding to flow path 171 and other positions. This will cause non-uniformity in the X direction of the flow of processed fluid that flows from flow path 173 into processing space SP, leading to turbulence.

[0033] By arranging the flow paths 171 and 173 differently in the Z direction, the straight-line flow of the processing fluid from flow path 171 to flow path 173 is eliminated, making it possible to introduce the processing fluid into the processing space SP as a uniform laminar flow in the width direction.

[0034] The processing fluid introduced from the introduction channel 17 configured in this way flows along the upper and lower surfaces of the support tray 15 within the processing space SP, and is discharged outside the processing container via the discharge channel 18 configured as follows. On the (-Y) side of the substrate S, the ceiling surface of the processing space SP and the upper surface 151 of the support tray 15 are both horizontal planes, and they face each other parallel to maintain a certain gap. This gap functions as the upstream section 181 of the discharge channel 18 (upper discharge channel 18a) that guides the processing fluid that has flowed along the upper surface 151 of the support tray 15 and the surface Sa of the substrate S to the fluid discharge section 55. This upstream section 181 has a wide cross-sectional shape that is narrow in the vertical direction (Z direction) and long in the horizontal direction (X direction).

[0035] The end of the upstream section 181 opposite the processing space SP is connected to the buffer space 182. The detailed structure will be described later, but the buffer space 182 is a space enclosed by the processing chamber 100, the lid member 14, and the sealing member 16. The width of the buffer space 182 in the X direction is equal to or greater than the width of the upstream section 181, and the height of the buffer space 182 in the Z direction is greater than the height of the upstream section 181. Therefore, the buffer space 182 has a larger flow path cross-sectional area than the upstream section 181.

[0036] The downstream portion 183 of the upper discharge channel 18a is connected to the upper part of the buffer space 182. The downstream portion 183 is a through-hole provided through the first member 11, which is the upper block constituting the processing chamber 100. Its upper end constitutes an output port 104 that opens to the upper surface of the processing chamber 100, and its lower end opens facing the buffer space 182.

[0037] Thus, in this embodiment, the discharge channel 18 on the upper side of the support tray 15, that is, the upper discharge channel 18a, consists of the following three regions, that is, (1) The upstream portion 181 formed between the upper surface 151 of the support tray 15 and the lower surface of the first member 11, (2) A downstream section 183 connected to the fluid discharge section 55, (3) An intermediate section (buffer space 182) that communicates with the upstream section 181 and the downstream section 183, It has.

[0038] Similarly, the bottom surface of the processing space SP and the lower surface of the support tray 15 are both horizontal planes, and they face each other parallel to maintain a certain gap. This gap functions as the upstream portion 185 of the discharge channel 18 (lower discharge channel 18b) that guides the processing fluid flowing along the lower surface of the support tray 15 to the fluid discharge section 55. Furthermore, the upstream portion 185 on the lower surface side of the support tray 15 is connected to the downstream portion 187 via a buffer space 186, similar to the upper surface side of the support tray 15. In other words, the discharge channel 18 (lower discharge channel 18b) on the lower surface side of the support tray 15 consists of the following three regions, namely: (1) The upstream portion 185 formed between the lower surface of the support tray 15 and the upper surface of the second member 12, (2) A downstream section 187 connected to the fluid discharge section 55, (3) An intermediate section (buffer space 186) that communicates with the upstream section 185 and the downstream section 187, respectively, It has.

[0039] In the processing space SP, the processing fluid that flows over the support tray 15 is sent to the output port 104 via the upstream section 181, buffer space 182, and downstream section 183 that constitute the upper discharge channel 18a of the discharge channel 18. The output port 104 is connected to the fluid discharge section 55 by piping 551, and a valve 552 is interposed in the middle of the piping 551.

[0040] Similarly, the processing fluid that flows below the support tray 15 in the processing space SP is sent to the output port 105 via the upstream section 185, buffer space 186, and downstream section 187 that constitute the lower discharge channel 18b of the discharge channel 18. The output port 105 is connected to the fluid discharge section 55 by piping 553, and a valve 554 is interposed in the middle of the piping 553.

[0041] Valves 552 and 554 are controlled by the control unit 90. When valves 552 and 554 open in response to a control command from the control unit 90, the processing fluid in the processing space SP is recovered to the fluid discharge section 55 via the piping 551 and 553.

[0042] As shown in Figure 4, the discharge channel 18 (upper discharge channel 18a, lower discharge channel 18b) is formed by the processing chamber 100 (upper member 11 and lower member 12), the support tray 15, and the lid member 14 each functioning as part of the channel wall.

[0043] An annular sealing member 16 is attached to the (-Y) side end face of the processing chamber 100, and an opening 101 is provided in the internal region surrounded by the sealing member 16. More specifically, recesses 111 and 121 are provided on the (-Y) side end faces of the first member 11 and the second member 12 that constitute the processing chamber 100, with their surfaces recessed toward the (+Y) side. At the lower end of the recess 111 of the first member 11, a flange-shaped partition wall 112 is provided that is thin in the vertical direction (Z direction) and protrudes in the (-Y) direction, with a width in the X direction being the same as or slightly larger than the width of the processing space SP.

[0044] The partition wall 112 is the lower (-Y) end of the first member 11, which extends in the (-Y) direction while facing the support tray 15, and partially separates the upstream section 181 and the buffer space 182 as shown in Figure 4. Furthermore, when the lid member 14 closes the opening 101, the (-Y) end of the partition wall 112 is separated from the (+Y) side surface of the lid member 14 by a predetermined gap. This gap serves as a flow path for the processing fluid and also as a connection point connecting the upstream section 181 and the buffer space 182. Therefore, the processing fluid (dotted line) flowing in the upstream section 181 passes through the (-Y) side of the partition wall 112, and then changes direction in the (+Z) direction before flowing into the buffer space 182.

[0045] Furthermore, a flange-shaped partition wall 122 is provided at the upper end of the recess 121 of the second member 12, with a width in the X direction being the same as or slightly larger than the width of the processing space SP, and a thin flange-shaped partition wall 122 protruding in the (-Y) direction in the vertical direction (Z direction). The function of the partition wall 122 is the same as that of the partition wall 112.

[0046] In other words, the partition wall 122 is the upper (-Y) side end of the second member 12, which extends in the (-Y) direction while facing the support tray 15, and partially separates the upstream section 185 from the buffer space 186. Therefore, the processing fluid flowing in the upstream section 185 passes through the (-Y) side of the partition wall 122, and then changes direction in the (-Z) direction before flowing into the buffer space 186.

[0047] The upper space above partition wall 112 functions as a buffer space 182 when its (-Y) side opening is closed by a cover member 14. Similarly, the lower space below partition wall 122 functions as a buffer space 186 when its (-Y) side opening is closed by a cover member 14. Downstream sections 183, 183 (Figure 2) are connected to the upper surface of recess 111 near both ends in the X direction. Downstream sections 183, 183 communicate with output ports 104, 104 provided on the upper surface of first member 11. Downstream sections 187, 187 are connected to the lower surface of recess 121 near both ends in the X direction. Downstream sections 187, 187 communicate with output ports 105, 105 provided on the lower surface of second member 12. A fluid discharge section 55 is connected to the output ports 104, 104, 105, 105 to recover the processed fluid.

[0048] Thus, the processed fluid flowing through the upstream sections 181 and 185 of the discharge channel 18 flows into the buffer spaces 182 and 186 through the gap between the partition walls 112 and 122 and the cover member 14. Therefore, at the connection point CP between the upstream sections 181 and 185 and the buffer spaces 182 and 186, the size of the gap between the partition walls 112 and 122 and the cover member 14 becomes the opening size of the channel in the height direction perpendicular to the width direction, i.e., the opening height H. Also, as shown in Figure 3, the gap between the partition walls 112 and 122 and the cover member 14 when the channel is viewed in the Z direction represents the cross-sectional shape of the channel at the connection point CP between the upstream sections 181 and 185 and the buffer spaces 182 and 186.

[0049] As shown in Figures 2 and 3, in the upper discharge channel 18a, the opening height H at the connection point CP differs depending on the position in the width direction (X direction). Specifically, as shown on the left of Figure 3, the opening height H is constant in the end regions Re at both ends in the width direction of the upper discharge channel 18a, but in the central region Rc further inside, the opening height H gradually increases towards the center. Here, coordinates Xa, Xb, and Xc represent the (-X) side end position, the (+X) side end position, and the central position, respectively, in the width direction of the upper discharge channel 18a.

[0050] Figures 5 and 6 illustrate the structure around the opening of the processing chamber. More specifically, Figure 5 is an external view showing the opening 101 of the processing chamber 100. Figure 6, in order to make the internal structure of the processing chamber 100 easier to see, omits the sealing member 16 and the boundary line between the first member 11 and the second member 12 from Figure 5, and instead shows the structures that are hidden in Figure 5 with hidden lines (dotted lines).

[0051] As shown in these figures, the central portion 112a of the partition wall 112 is cut out in a roughly V-shape. Due to this structure, the distance between the lid member 14 and the partition wall 112 changes with position, remaining roughly constant at both ends in the X direction, while increasing towards the center of the flow path in the central portion 112a. As a result, a flow path is formed in which the opening height H changes as described above. The reason for changing the opening height H with respect to the position in the width direction at the connection between the upstream portion 181 and the buffer space 182 is as follows.

[0052] Patent Document 1, previously disclosed by the applicant, shows that by providing notches in the partition walls 112 and 122 to change the opening height H, it is possible to adjust the balance between the flow of the processed fluid flowing into the discharge channel and the flow of the processed fluid discharged therefrom, thereby preventing backflow of the processed fluid discharged from the processing space SP. However, it does not specifically show the effects obtained when the manner in which the opening height is changed is a specific shape different from that disclosed in Patent Document 1.

[0053] The inventors of this application focused on the fact that processing defects such as residual contaminants and pattern collapse on the substrate S after processing tend to occur concentrated at the downstream end of the substrate S in the direction of flow of the processing fluid. As a result of further research, they obtained the following findings. Specifically, such processing defects tend to occur more frequently locally near the (-Y) side end of the substrate S, especially in the central part in the X direction. The reason for this is thought to be that the liquid (IPA) that has entered the gap between the substrate S and the support tray 15, that is, between the lower surface of the substrate S and the upper surface of the recess 152 of the support tray 15, is not sufficiently discharged and remains around the substrate S, especially near the (-Y) side end, until the later stages of the supercritical drying process. This is because it was observed that when the support tray 15 is provided with through holes to allow such residual liquid to fall downward, the occurrence of processing defects is relatively minor, while when there are no (or small) through holes, the above-mentioned localized processing defects are more likely to occur.

[0054] Therefore, in particular, in the upper discharge channel 18a that discharges liquid that has entered the gap between the substrate S and the support tray 15, it is necessary to create a flow of processing fluid that effectively discharges such residual liquid. Accordingly, in the upper discharge channel 18a of this embodiment, at the connection point CP between the upstream section 181 and the buffer space 182, the opening height H is made relatively small in the end regions Re at both ends in the width direction (X direction) to increase the pressure loss in the channel. On the other hand, in the central region Rc, the opening height H is increased so that the pressure loss decreases as it approaches the center. As a result, the flow of processing fluid from the upstream section 181 to the buffer space 182 exhibits the following behavior.

[0055] Figure 7 shows the flow of the processed fluid near the partition wall. More specifically, Figure 7(a) schematically shows the flow of the processed fluid in the upper discharge channel 18a, and Figure 7(b) shows the flow of the processed fluid flowing from the upstream section 181 into the buffer space 182. In these figures, the dashed arrows schematically represent the flow of the processed fluid. The density of the arrows schematically represents the flow rate, and the length represents the flow velocity.

[0056] As shown in Figures 7(a) and 7(b), at the connection point CP between the upstream section 181 and the buffer space 182, the pressure loss of the flow path is higher at both ends and lower in the center. Therefore, the flow that flows through the center into the buffer space 182 is dominant. In other words, the flow velocity and flow rate of the processed fluid are greater in the center than at the ends. This has the following two effects.

[0057] Firstly, as shown in Figure 7(a), in the upstream portion 181 of the upper discharge channel 18a, a stronger flow is created in the central part of the upper surface 151 of the support tray 15 in the width direction (X direction) than in the outer part. This promotes the discharge of residual liquid that has entered the gap between the substrate S and the support tray 15.

[0058] Secondly, as shown in Figure 7(b), the processing fluid flowing into the buffer space 182 forms a flow from the center to both ends, i.e., the downstream section 185, so that the processing fluid can be discharged smoothly from the buffer space 182. Therefore, it is possible to suppress the stagnation of the processing fluid that has flowed into the buffer space 182 and prevent backflow into the processing space SP.

[0059] Thus, in the first embodiment, a V-shaped notch is provided in the partition wall 112 separating the upstream portion 181 of the upper discharge channel 18a from the buffer space 182, thereby giving the partition wall 112 the function of a "flow straightening section" that regulates the flow of the processed fluid. Of the effects obtained by this, the second effect is discussed in Patent Document 1, but the first effect is not mentioned.

[0060] Furthermore, since the lower discharge channel 18b discharges processing fluid that does not directly come into contact with the substrate S, the same flow straightening function as the upper discharge channel 18a is essentially unnecessary. For this reason, as shown in Figures 5 and 6, the tip of the partition wall 122 may be configured to be in a straight line in the X direction. Also, as described in Patent Document 1, appropriate notches may be provided to adjust the balance between the flow of processing fluid flowing from the upstream section 185 into the buffer space 186 and the flow of processing fluid in the buffer space 183.

[0061] Figure 8 illustrates the structure around the opening of the processing chamber in a second embodiment of the substrate processing apparatus according to the present invention. In Figure 8 and its description, structures having substantially the same function as those described in Figures 5 and 6 are denoted by the same reference numerals and their detailed descriptions are omitted.

[0062] The main difference between the second embodiment and the first embodiment lies in the configuration of the flow straightening section. In the first embodiment, a part of the first member 11 (partition wall 112) and a part of the second member 12 (partition wall 122) function as the "flow straightening section." In contrast, in the second embodiment, independent partition flow straightening members 191 and 192 are detachably attached to the first member 11 and the second member 12, respectively.

[0063] As shown in Figure 8, the bulkhead rectifier member 191 is an angle-shaped member with a substantially L-shaped cross-section. Of the two wing portions constituting this bulkhead rectifier member 191, a substantially V-shaped notch portion 191a is provided in the widthwise center of the wing portion extending in the (-Y) direction. The other wing portion is fixed to the first member 11 by fixing screws 113a while in close contact with the recess 101a of the first member 11. In this way, the bulkhead rectifier member 191 performs both bulkhead and rectification functions, similar to the bulkhead 112 of the first embodiment. Similarly, a bulkhead rectifier member 192 is fixed to the lower part of the opening 101b by fixing screws 123a and performs a bulkhead function.

[0064] In this second embodiment, since the partition rectifier members 191 and 192 are detachable, partition rectifier members 191 and 192 corresponding to the type of substrate S and processing conditions can be used. For example, as described below, multiple partition rectifier members 191 with different notch portion 191a shapes and sizes can be prepared in advance. Then, partition rectifier members 191 that are suitable for the type of substrate S and processing conditions can be selected and mounted in the processing chamber 100. This makes it possible to handle a wide variety of substrates S and processing conditions, thereby increasing the versatility of the substrate processing apparatus 1.

[0065] Figures 9 and 10 illustrate other configurations of the flow straightening section. In the partition wall 112 of the first embodiment and the partition wall flow straightening member 191 of the second embodiment, a substantially V-shaped notch is provided in the center in the X direction. The shape of the notch for obtaining the effects of the present invention is not limited to this, and various shapes can be adopted as shown in Figures 9 and 10. Note that the differences in these shapes can be uniquely shown by the change in the opening height H with respect to the position in the X direction, so here the shapes will be shown by a graph representing the relationship between the position in the X direction and the opening height H.

[0066] In the example shown in Figure 9(a), there is no section at both ends where the opening height H is constant; the opening height H continuously increases from both ends toward the center. Even with this configuration, it is possible to form a flow path in which the pressure loss decreases as you move from the ends toward the center, and the same effects as in the above embodiment can be obtained.

[0067] In other words, any flow path cross-sectional shape is acceptable such that the pressure loss is relatively large at both ends of the flow path and decreases towards the center. For example, a shape in which the opening height H increases monotonically in a broad sense from the ends to the center is preferred. This can include both examples, such as the one shown in Figure 3 (left), where there are sections at both ends where the opening height H is constant, and the example shown in Figure 9(a), where the opening height H changes monotonically throughout the entire area. This is also true for the various shapes exemplified below.

[0068] Furthermore, as shown in Figures 9(b) and 9(c), the change in opening height H may be curvilinear. In this case as well, the height change may occur only in the central part, as shown in Figure 9(b), or the opening height H may change continuously over the entire X-direction, as shown in Figure 9(c). The shape of the curve can be set in various ways depending on the purpose, and for example, it may be approximated by a straight line in each section. Also, in the embodiment shown in Figure 9(d), the opening height H changes in a step-like manner. Even with such a shape, it is possible to form a flow path in which the pressure loss is large at both ends and smaller in the central part.

[0069] Furthermore, as shown in Figure 10, by devising the shape of the repeatedly provided irregularities, it is possible to form a flow path in which the pressure loss is small in the center and large at both ends when viewed macroscopically. In the example shown in Figure 10(a), irregularities with a constant opening height H appear multiple times in the X direction, and at least one of the width of the recess and the width of the protrusion differs depending on the position in the X direction. In this case, microscopically, parts with high and low pressure loss appear alternately, but when the flow of the processed fluid is considered macroscopically, it can be said that a flow path is formed in which the pressure loss is lower towards the center, as shown by the dotted line. Also, in the example shown in Figure 10(b), the height difference of the irregularities repeated at a constant pitch differs depending on the position in the X direction. Even with such a configuration, it is possible to form a flow path in which the pressure loss is lower towards the center when viewed macroscopically, similar to the example in Figure 10(a).

[0070] As described above, in the first and second embodiments, the processing chamber 100, mainly composed of the first to third members 11 to 13, functions as the "processing container" of the present invention. Of these, the cavity 110 corresponds to the "first cavity" of the present invention, and the recess 111 corresponds to the "second cavity" of the present invention. The lid member 14 corresponds to an example of the "lid" of the present invention. The opening 101 corresponds to the "opening" of the present invention.

[0071] Furthermore, in the above embodiment, the upstream section 181, buffer space 182, and downstream section 183 correspond to the "upstream section," "buffer space," and "downstream section" of the "upper discharge channel" in the present invention, respectively. Also, the upstream section 185, buffer space 186, and downstream section 187 correspond to the "upstream section," "buffer space," and "downstream section" of the "lower discharge channel" in the present invention, respectively.

[0072] Furthermore, in the first embodiment, the partition wall 112 functions as the "flow straightening section" of the present invention, while in the second embodiment, the partition wall flow straightening member 191 functions as both the "partition wall flow straightening member" and the "flow straightening section" of the present invention. Also, in the above embodiments, the opening height H corresponds to the "opening dimension" of the present invention. Moreover, in the above embodiments, the X direction corresponds to the "first direction" of the present invention, and the Y direction corresponds to the "second direction" of the present invention.

[0073] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, the side surface of the lid member 14 that opens and closes the opening 101 of the processing chamber 100 constitutes part of the discharge channel, but the present invention can be applied even if the configuration is not like this. For example, a discharge channel may be pre-formed in the processing chamber, similar to the inlet channel 17 in this embodiment.

[0074] Furthermore, in the above embodiment, the notch shape of the partition wall 112 is symmetrical with respect to its central position Xc. However, the notch shape may be asymmetrical. Also, in the modified examples shown in Figures 10(a) and 10(b), the notch is positioned such that the opening height H is maximized at the central position Xc of the flow path. However, even if the opening height H is small at position Xc, it is possible to reduce the macroscopic pressure loss in the central part by increasing the opening height H around it.

[0075] In this embodiment, the processing fluid is supplied to the processing space SP from the side opposite to the opening 101 and discharged toward the opening 101. However, this flow direction may be reversed.

[0076] Furthermore, the various chemical substances used in the processing of the above embodiments are merely examples, and various other substances can be used as substitutes, as long as they are consistent with the technical concept of the present invention as described above.

[0077] As described above with specific embodiments as examples, in the substrate processing apparatus according to the present invention, for example, the rectifier section may be configured such that the pressure loss in the discharge channel increases monotonically in a broad sense along the first direction from the center to both ends. With such a configuration, the flow of the processing fluid discharged from the processing space can be made stronger in the center than at both ends in the first direction. This effectively promotes the discharge of the processing fluid that has entered between the substrate and the support tray.

[0078] A specific configuration to achieve this can be one in which the opening size of the discharge channel along the first direction decreases monotonically in a broad sense from the center to both ends. Alternatively, the opening size can decrease monotonically in a narrow sense in a central region within a predetermined distance from the center in the first direction of the discharge channel, and the opening size remains constant outside the central region. With such a configuration, the pressure loss is high in the narrow part of the opening and low in the wide part, making it a suitable configuration for realizing the present invention.

[0079] Furthermore, the substrate processing apparatus according to the present invention may be configured such that an opening is provided on the side of the processing container to connect the processing space with the external space, and a lid is provided to open and close the opening, and the support tray is attached to the surface of the lid that covers the opening, in which case, with the support tray housed in the processing space, the space sandwiched between the ceiling surface of the inner wall surface of the processing container facing the processing space and the upper surface of the support tray can form the upstream section. With such a configuration, the flow of the processing fluid in the processing space can be separated into an upper side and a lower side by the support tray, and these can be discharged individually.

[0080] In this case, the processing container is provided with a first cavity that serves as a processing space and a second cavity that serves as a buffer space, both connected to each other. A partition wall may also be provided to separate the first cavity and the second cavity. In such a configuration, the gap between the lid and the partition wall forms a connection point, and the partition wall can function as a flow straightening section.

[0081] Furthermore, the partition wall may be a partition wall rectifier member that is detachably attached to the processing vessel. While the processing vessel requires high rigidity as a high-pressure vessel, the partition wall requires precise machining. Therefore, by making these components separate, it becomes possible to manufacture each using a manufacturing method suitable for that component. In addition, since only the partition wall rectifier member can be replaced, the workability of maintenance and repair work is improved. Moreover, by replacing the partition wall rectifier member with one of a different shape, the device can be made highly versatile and applicable to various purposes.

[0082] Furthermore, for example, the lower discharge channel of the discharge channel, which discharges the processed fluid that has passed below the support tray, can also be provided with an upstream section that communicates with the processing space below the support tray and has a channel cross-section in which the opening dimension in the first direction is larger than the opening dimension in the second direction, a buffer space that communicates with the upstream section and has a larger channel cross-sectional area than the upstream section, and a downstream section that connects the fluid discharge section to a pair of openings provided at both ends of the buffer space in the first direction.

[0083] With this configuration, the processing fluid that passes under the support tray can be discharged separately from the processing fluid that passes over the substrate. By discharging the processing fluid flowing out of the processing space to the outside via the buffer space, the processing fluid can be discharged without impairing the smooth flow in the processing space. Since the lower discharge channel does not need to discharge the processing fluid that has entered between the substrate and the support tray, the flow straightening section provided in the upper discharge channel is essentially unnecessary. [Industrial applicability]

[0084] This invention can be applied to all substrate processing technologies in which a substrate is processed by a processing fluid in a processing container. In particular, it can be applied to processing using high-pressure fluids, such as substrate drying processes in which substrates such as semiconductor substrates are dried by supercritical fluids. [Explanation of Symbols]

[0085] 1. Substrate processing device 14 Lid member 15 Support tray 18 Discharge channel 18a Upper discharge channel 18b Lower discharge channel 55 Fluid discharge part 57 Fluid supply section 100 Processing chamber (processing container) 101 Aperture 110 Cavity (First cavity) 111,121 Recess (second cavity) 112 Bulkhead (rectifier) 181,185 Upstream section 182,186 buffer space 183,187 downstream 191 Partition wall flow straightening member H Opening height (opening dimensions) Rc central area Re end area S substrate SP Processing Space X 1st direction Y Second direction

Claims

1. A flat support tray that supports the substrate placed on the top surface in a horizontal position, A processing container having a processing space capable of accommodating the substrate together with the support tray, A fluid supply unit that supplies a processing fluid for supercritical processing to the processing space from one end of the processing space, A fluid discharge section is provided on the other end of the substrate, opposite to the one end, which communicates with the processing space, and the processing fluid is discharged via a discharge channel. Equipped with, When the direction perpendicular to the flow direction of the processing fluid and parallel to the main surface of the substrate is defined as the first direction, and the direction perpendicular to the flow direction and the first direction is defined as the second direction, The discharge channels are provided to separately discharge the processing fluid that has passed over the substrate and the processing fluid that has passed below the support tray, and the upper discharge channel that discharges the processing fluid that has passed over the substrate is provided, An upstream portion that communicates with the processing space above the substrate and has a flow channel cross-section in which the opening dimension along the first direction is larger than the opening dimension along the second direction, A buffer space that communicates with the upstream section and has a larger flow channel cross-sectional area than the upstream section, A downstream section connecting a pair of openings provided at both ends in the first direction of the buffer space to the fluid discharge section, A flow straightening section is provided at the connection between the upstream section and the buffer space, which makes the pressure loss in the central section in the first direction lower than the pressure loss at both ends. It has, In the rectification section, the pressure loss of the discharge channel increases monotonically in a broad sense along the first direction from the central part toward both ends, in the substrate processing apparatus.

2. The substrate processing apparatus according to claim 1, wherein in the rectifying section, the opening size of the discharge channel along the second direction decreases monotonically in a broad sense from the central part toward both ends.

3. The substrate processing apparatus according to claim 2, wherein in the rectifying section, the opening size decreases in a narrow sense monotonically in a central region within a predetermined distance from the center in the first direction of the discharge flow path, and the opening size remains constant outside the central region.

4. An opening is provided on the side of the processing container to connect the processing space with the external space. The system further includes a lid that opens and closes the aforementioned opening, The support tray is attached to the surface of the lid that covers the opening. The substrate processing apparatus according to any one of claims 1 to 3, wherein, with the support tray housed in the processing space, the space sandwiched between the ceiling surface of the inner wall surface of the processing container facing the processing space and the upper surface of the support tray constitutes the upstream portion.

5. The processing container is provided with a first cavity that serves as the processing space and a second cavity that serves as the buffer space, both connected to each other, and a partition wall is further provided to separate the first cavity and the second cavity. The substrate processing apparatus according to claim 4, wherein the gap between the lid and the partition wall constitutes the connection portion, and the partition wall functions as the flow straightening portion.

6. The substrate processing apparatus according to claim 5, wherein the partition wall is a partition wall flow straightening member that is detachably provided to the processing container.

7. Of the aforementioned discharge channels, the lower discharge channel that discharges the processed fluid that has passed below the support tray contains: An upstream section below the support tray that communicates with the processing space and has a flow path cross-section in which the opening dimension along the first direction is larger than the opening dimension along the second direction, A buffer space that communicates with the upstream section and has a larger flow channel cross-sectional area than the upstream section, A downstream portion connecting a pair of openings provided at both ends in the first direction of the buffer space and the fluid discharge portion. A substrate processing apparatus according to any one of claims 1 to 3, wherein the following is provided.

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