JP2024045870A - Substrate processing equipment - Google Patents

Abstract

[Problem] In a substrate processing technique in which a substrate is processed with a processing fluid in a processing space of a processing vessel, the adhesion of contaminants and pattern collapse that tend to occur in the center of the substrate are effectively prevented. [Solution] The substrate processing apparatus according to the present invention separately discharges processing fluid that has passed above and below the substrate, and the upper discharge flow path that discharges the processing fluid that has passed above the substrate is provided with an upstream portion that communicates with the processing space above the substrate, a buffer space that communicates with the upstream portion and has a larger flow path cross-sectional area than the upstream portion, a downstream portion that connects a pair of openings provided at both ends of the buffer space to the fluid discharge portion, and a straightening 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 Figure] Figure 3

Description

The present invention relates to a substrate processing apparatus that processes a substrate with a processing fluid in a processing container.

Processing processes for various substrates, such as semiconductor substrates and glass substrates for display devices, include treating the substrate surface with various processing fluids. Processing using liquids such as chemicals and rinsing liquids as processing fluids has been widely used in the past, but in recent years, processing using supercritical fluids has also been put to practical use. In particular, when processing substrates with fine patterns formed on their surfaces, supercritical fluids, which have lower surface tension than liquids, can penetrate deep into the gaps in the patterns, making processing more efficient and reducing the risk of pattern collapse due to surface tension during drying.

For example, Patent Document 1 previously disclosed by the applicant of the present invention describes a substrate processing apparatus that performs a drying process on a substrate using a supercritical fluid. In Patent Document 1, a problem is raised in the flow balance in a discharge channel for discharging a processing fluid after processing a substrate in a processing container (high-pressure chamber) into which a processing fluid in a supercritical state is introduced. Specifically, an imbalance between the amount of processing fluid flowing into the discharge channel and the amount of processing fluid discharged from the discharge channel causes backflow of the processing fluid, which causes the substrate to be recycled. It has been proposed to provide a rectifier in the discharge flow path, as this may lead to pollution.

JP2022-083526A

Patent Document 1 shows the possibility of adjusting the balance between the processing fluid flowing toward the rectification section and the processing fluid after passing through the rectification section by providing a rectification section in the discharge flow path. However, there is no detailed description of specific issues and the configuration of the rectifier to solve them. For example, according to knowledge obtained by the applicant after filing Patent Document 1, contamination of the substrate and pattern collapse due to backflow of the processing fluid occur at the center of the substrate in the width direction perpendicular to the flow direction of the processing fluid. It has been found that this is particularly noticeable.

However, Patent Document 1 does not specifically disclose such issues or the structure of the rectifier that can solve them. In this respect, it can be said that there is still room for improvement in the above-mentioned conventional technology.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a technique that can effectively prevent the adhesion of contaminants and pattern collapse that tend to occur in the center of a substrate.

One aspect of the present invention includes a flat support tray that supports a substrate placed on an upper surface in a horizontal position, a processing container having a processing space that can accommodate the substrate together with the support tray, and a processing container that includes a processing space that can accommodate 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; and a discharge provided in communication with the processing space at the other end opposite to the one end with the substrate in between. The substrate processing apparatus includes a fluid discharge section that discharges the processing fluid via a flow path. Here, among the directions perpendicular to the flow direction of the processing fluid, a direction parallel to the main surface of the substrate is defined as a first direction, and a direction perpendicular to the flow direction and the first direction is defined as a second direction, The discharge channel is provided to separately discharge the processing fluid that has passed above the substrate and the processing fluid that has passed below the support tray, and among them, the processing fluid that has passed above the substrate is discharged. The upper discharge channel for discharging includes an upstream channel that communicates with the processing space above the substrate and has a channel cross section in which an opening dimension along the first direction is larger than an opening dimension along the second direction. a buffer space that communicates with the upstream section and has a larger cross-sectional area than the upstream section; a pair of openings provided at both ends of the buffer space in the first direction; and the fluid discharge section. and a rectifying section that is provided at a connection section between the upstream section and the buffer space and makes the pressure loss at the central section in the first direction lower than the pressure loss at both ends. There is.

In the invention configured in this way, the flow straightening section provided in the discharge flow path of the treatment fluid is configured so that the pressure loss is low in the center of the discharge flow path and high at both ends. Therefore, the flow velocity and flow rate of the treatment fluid flowing into the buffer space is higher in the center than at both ends. This forms a flow of the treatment fluid in the buffer space from the center to both ends.

As will be described 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 has entered between the substrate and the support tray is not discharged properly, and the processing fluid mixed with contaminants accumulates around the periphery of the substrate. Therefore, by controlling the flow of processing fluid by creating a difference in pressure loss in the discharge flow path as described above, it is possible to promote discharge from the center and prevent accumulation, thereby reducing processing defects such as the adhesion of contaminants and pattern collapse.

As described above, according to the present invention, by creating a difference in pressure loss between the center and both ends of the discharge flow path, discharge of the processing fluid from the center can be promoted, thereby effectively preventing adhesion of contaminants and pattern collapse that tend to occur in the center of the substrate.

1 is a diagram showing a schematic configuration of a first embodiment of a substrate processing apparatus according to the present invention. FIG. 2 is a schematic diagram showing the contour of a flow path of a process fluid. FIG. 3 is a plan view schematically showing a flow path of a processing fluid. FIG. 3 is a side cross-sectional view showing the detailed structure of a discharge flow path. FIG. 3 is a diagram illustrating a structure around an opening of a processing chamber. 1 is a diagram illustrating a structure around an opening of a processing chamber. FIG. 13 is a diagram showing the flow of a process fluid near a partition wall. 13 is a diagram illustrating a structure around an opening of a processing chamber according to a second embodiment; 13A and 13B are diagrams illustrating other configurations of the rectification unit. FIG. 7 is a diagram illustrating another configuration of the rectifying section.

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

The "substrate" in this embodiment can be any of a variety of substrates, including semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks. In the following, a substrate processing apparatus used primarily for processing semiconductor wafers will be described with reference to the drawings, but the apparatus can also be used for processing the various substrates exemplified above.

The substrate processing apparatus 1 includes a processing unit 10, a supply unit 50, and a control unit 90. The processing unit 10 is the main body for performing the supercritical drying process, and the supply unit 50 supplies the processing unit 10 with chemicals and power necessary for the process.

The control unit 90 controls each part of these devices to realize predetermined processing. 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 that the CPU 91 executes, and a It is equipped with an interface 94 and the like for exchanging information. The operation of the apparatus, which will be described later, is realized by the CPU 91 executing a control program written in advance in the storage 93 and causing each part of the apparatus to perform a predetermined operation.

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 of which is formed from a metal block. The first member 11 and the second member 12 are joined in the vertical direction by a joining member (not shown), and the third member 13 is joined to the (+Y) side by a joining member (not shown), forming the processing chamber 100 with a structure in which the inside is a cavity 110. The internal space of this cavity 110 is the processing space SP in which processing is performed on the substrate S. The substrate S to be processed is loaded into the processing space SP and undergoes processing. A slit-shaped opening 101 that extends elongatedly in the X direction is formed on the (-Y) side of the processing chamber 100, and the processing space SP communicates with the outside space via the opening 101.

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 attached to the (+Y) side surface of the lid member 14 in a horizontal position, and the upper surface of the support tray 15 serves as a support surface on which the substrate S can be placed. More specifically, the support tray 15 has a structure in which a recess 152, which is slightly larger than the planar size of the substrate S, is provided on a substantially flat upper surface 151. By housing 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 Sa to be processed (hereinafter sometimes simply referred to as "substrate surface") 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.

The lid member 14 is supported by a support mechanism (not shown) so that it can move horizontally in the Y direction. The lid member 14 can also be moved forward and backward relative to the processing chamber 100 by an advance/retract mechanism 53 provided in the supply unit 50. Specifically, the advance/retract 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 this linear motion mechanism moves the lid member 14 in the Y direction. The advance/retract mechanism 53 operates in response to a control command from the control unit 90.

When the cover member 14 moves in the (-Y) direction, the support tray 15 is pulled out from the processing space SP to the outside through the opening 101, allowing access to the support tray 15 from the outside. In other words, it becomes possible to place a substrate S on the support tray 15 and to remove the substrate S placed on the support tray 15. On the other hand, when the cover member 14 moves in the (+Y) direction, the support tray 15 is accommodated in the processing space SP. When 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.

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

The lid member 14 moves in the (+Y) direction to close the opening 101, thereby sealing the processing space SP. A seal member 16 is provided between the (+Y) side surface of the lid member 14 and the (-Y) side surface of the processing chamber 100, and keeps the processing space SP airtight. The seal member 16 may be an annular member made of an elastic resin material, such as rubber. The lid member 14 is fixed to the processing chamber 100 by a locking mechanism (not shown). With the processing space SP thus kept airtight, processing of the substrate S is carried out within the processing space SP.

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

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

2 and 3 are diagrams schematically showing flow paths of processing fluid. More specifically, FIG. 2 is a schematic diagram showing the outline of the flow path, and FIG. 3 is a plan view thereof. Moreover, FIG. 4 is a side sectional view showing the detailed structure of the discharge flow path. Hereinafter, the structure of the processing fluid flow path will be described with reference to FIGS. 1 to 4.

The fluid flow path 17 leading from the input ports 102, 103 to the processing space SP functions as an introduction flow path that introduces the processing fluid supplied from the fluid supply unit 57 into the processing space SP. Specifically, a flow path 171 is connected to the input port 102. A buffer space 172 is provided at the end of the flow path 171 opposite the input port 102, where the cross-sectional area of the flow path is rapidly expanded.

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

Desirably, 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 accommodated 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 the shape of a horizontally elongated slit facing the processing space SP.

A processing fluid flow path is similarly formed below the support tray 15. Specifically, a flow path 175 is connected to the input port 103. A buffer space 176 is provided at the end of the flow path 175 on the opposite side from the input port 103, and the buffer space 176 is formed so that the cross-sectional area of the flow path increases rapidly.

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 long and wide in the horizontal direction (X direction), and the cross-sectional shape is approximately constant in the flow direction of the processing fluid. The end of the flow path 177 opposite the buffer space 176 is an outlet 178 that opens onto the processing space SP, and the processing fluid is introduced into the processing space SP from this outlet 178.

Desirably, the height of the flow path 177 is equal to the distance between the bottom surface 110b of the processing space SP and the lower 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 lower 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 the shape of a horizontally elongated slit facing the processing space SP.

In the Z direction, it is desirable that the arrangement positions of flow path 171 and flow path 173 are different. When both are at the same height, part of the processing fluid that flows from flow path 171 into buffer space 172 will flow straight into flow path 173. If this happens, in the width direction of the flow path perpendicular to the flow direction, that is, in the X direction, there is a risk of a difference in the flow rate and flow speed of the processing fluid flowing into flow path 173 between the position corresponding to flow path 171 and other positions. This causes non-uniformity in the X direction in the flow of the processing fluid flowing from flow path 173 into processing space SP, resulting in turbulence.

By arranging the flow path 171 and the flow path 173 differently in the Z direction, the processing fluid does not flow straight from the flow path 171 to the flow path 173, and the processing fluid flows as a uniform laminar flow in the width direction. can be introduced into the processing space SP.

The processing fluid introduced from the inlet flow path 17 configured in this manner flows along the upper and lower surfaces of the support tray 15 in the processing space SP, and is discharged outside the processing vessel via the discharge flow path 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 each other with a certain gap. This gap functions as the upstream portion 181 of the discharge flow path 18 (upper discharge flow path 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 portion 181 has a cross-sectional shape that is narrow in the vertical direction (Z direction) and long and wide in the horizontal direction (X direction).

The end of the upstream portion 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 surrounded by the processing chamber 100, the lid member 14, and the seal member 16. The width of the buffer space 182 in the X direction is equal to or greater than the width of the upstream portion 181, and the height of the buffer space 182 in the Z direction is greater than the height of the upstream portion 181. Therefore, the buffer space 182 has a larger flow path cross-sectional area than the upstream portion 181.

The downstream portion 183 of the upper discharge flow path 18a is connected to the upper portion of the buffer space 182. The downstream portion 183 is a through hole that penetrates the first member 11, which is the upper block that constitutes the processing chamber 100. Its upper end constitutes the output port 104 that opens into the upper surface of the processing chamber 100, and its lower end opens toward the buffer space 182.

As described above, in the present embodiment, the discharge channel 18 on the upper surface side of the support tray 15, that is, the upper discharge channel 18a has the following three regions, that is,
(1) an 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 part (buffer space 182) communicating with the upstream part 181 and the downstream part 183, respectively;
have.

Similarly, the bottom surface of the processing space SP and the lower surface of the support tray 15 are both horizontal planes, and the two face each other in parallel with a certain gap therebetween. This gap functions as the upstream portion 185 of the discharge flow passage 18 (lower discharge flow passage 18b) that guides the processing fluid flowing along the lower surface of the support tray 15 to the fluid discharge portion 55. 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. That is, the discharge flow passage 18 (lower discharge flow passage 18b) on the lower surface side of the support tray 15 is divided into the following three regions, that is,
(1) an 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 portion 187 connected to the fluid discharge portion 55;
(3) an intermediate portion (buffer space 186) that communicates with the upstream portion 185 and the downstream portion 187,
have.

The processing fluid that has flowed above the support tray 15 in the processing space SP is sent to the output port 104 through the upstream section 181, buffer space 182, and downstream section 183 that constitute the upper discharge channel 18a of the discharge channel 18. Ru. The output port 104 is connected to the fluid discharge part 55 by a pipe 551, and a valve 552 is inserted in the middle of the pipe 551.

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 portion 185, the buffer space 186, and the downstream portion 187 that constitute the lower discharge flow path 18b of the discharge flow path 18. The output port 105 is connected to the fluid discharge part 55 by a pipe 553, and a valve 554 is inserted in the middle of the pipe 553.

The valves 552 and 554 are controlled by the control unit 90. When the valves 552 and 554 are opened in response to a control command from the control unit 90, the processing fluid in the processing space SP is collected in the fluid discharge section 55 via the pipes 551 and 553.

As shown in FIG. 4, the discharge flow path 18 (upper discharge flow path 18a, lower discharge flow path 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 flow path wall surface.

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

The partition wall 112 is the lower end on the (-Y) side of the first member 11 that extends in the (-Y) direction while facing the support tray 15, and partially connects the upstream portion 181 and the buffer space 182, as shown in FIG. It is divided into Furthermore, when the lid member 14 closes the opening 101, the (−Y) side tip 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 serves as a connection portion that connects the upstream portion 181 and the buffer space 182. Therefore, the processing fluid (dotted line) flowing through the upstream section 181 passes through the (-Y) side of the partition wall 112, changes direction in the (+Z) direction, and flows into the buffer space 182.

Further, at the upper end of the recess 121 of the second member 12, there is a flange-shaped partition wall 122 whose width in the X direction is the same as or slightly larger than the width of the processing space SP, and which is thin in the vertical direction (Z direction) (- Y) is provided to protrude in the direction. The function of the partition wall 122 is also similar to that of the partition wall 112.

That is, the partition wall 122 is the upper end portion on the (-Y) side of the second member 12 that extends in the (-Y) direction while facing the support tray 15, and partially separates the upstream portion 185 from the buffer space 186. Therefore, the processing fluid flowing through the upstream portion 185 passes through the (-Y) side of the partition wall 122, then changes direction in the (-Z) direction and flows into the buffer space 186.

The upper space above the partition wall 112 functions as a buffer space 182 by closing its (-Y) side opening with the lid member 14. Further, the lower space below the partition wall 122 functions as a buffer space 186 by closing its (-Y) side opening with the lid member 14. Downstream portions 183, 183 (FIG. 2) are connected to the upper surface of the recessed portion 111 near both ends thereof in the X direction. The downstream regions 183, 183 communicate with output ports 104, 104 provided on the top surface of the first member 11. Furthermore, downstream regions 187, 187 are connected to the lower surface of the recess 121 near both ends thereof in the X direction. The downstream regions 187, 187 communicate with output ports 105, 105 provided on the lower surface of the second member 12. A fluid discharge section 55 is connected to the output ports 104, 104, 105, and 105 to collect the processing fluid.

In this way, the processing fluid flowing through the upstream portions 181, 185 of the discharge flow path 18 flows into the buffer spaces 182, 186 through the gaps between the partitions 112, 122 and the lid member 14. Therefore, at the connection portion CP between the upstream portions 181, 185 and the buffer spaces 182, 186, the size of the gap between the partitions 112, 122 and the lid member 14 is the opening size of the flow path in the height direction perpendicular to the width direction, that is, the opening height H. In addition, as shown in Figure 3, the gap between the partitions 112, 122 and the lid member 14 when the flow path is viewed in the Z direction represents the cross-sectional shape of the flow path at the connection portion CP between the upstream portions 181, 185 and the buffer spaces 182, 186.

As shown in FIGS. 2 and 3, in the upper discharge channel 18a, the opening height H at the connecting portion CP varies depending on the position in the width direction (X direction). Specifically, as shown on the left side of FIG. 3, the opening height H is constant in the end regions Re at both ends in the width direction of the upper discharge flow path 18a, but in the central region Rc inside this, the opening height H is constant. The opening height H gradually increases towards the end. Here, coordinates Xa, Xb, and Xc indicate the (-X) side end position, (+X) side end position, and center position, respectively, in the width direction of the upper discharge flow path 18a.

Figures 5 and 6 are diagrams illustrating 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. Also, in order to make the internal structure of the processing chamber 100 easier to see, Figure 6 omits the illustration of the seal member 16 and the boundary line between the first member 11 and the second member 12 from Figure 5, and instead shows the structure hidden in Figure 5 by hidden lines (dotted lines).

As shown in these figures, the central portion 112a of the partition wall 112 is cut out in a substantially V-shape. With this structure, the distance between the lid member 14 and the partition wall 112 changes depending on the position, and is approximately constant at both ends in the X direction, while increasing toward the center of the flow path in the central portion 112a. As a result, a flow path whose opening height H changes as described above is formed. The reason why the opening height H is changed depending on the position in the width direction at the connection portion between the upstream portion 181 and the buffer space 182 is as follows.

In Patent Document 1 previously disclosed by the applicant of the present application, by providing notches in the partition walls 112 and 122 and changing the opening height H, the flow of the processing fluid flowing into the discharge channel and the processing fluid discharged from there. It has been shown that it is possible to adjust the balance with the flow of the processing fluid and prevent the backflow of the processing fluid discharged from the processing space SP. However, the effects obtained when the opening height changes in a specific shape different from that disclosed in Patent Document 1 are not specifically shown.

The inventors of the present application have focused on the fact that processing defects such as residual contaminants and pattern collapse on the substrate S after processing occur intensively at the downstream end of the substrate S in the flow direction of the processing fluid, and have obtained the following findings as a result of further research. That is, such processing defects tend to occur locally more frequently near the (-Y) end of the substrate S, especially in the center in the X direction. The cause of 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) end, until the later stage of the supercritical drying process. This is because it has been observed that when the support tray 15 has a through hole that allows such residual liquid to fall downward, the occurrence of processing defects is relatively minor, while when there is no through hole (or the through hole is small), the above-mentioned local processing defects are likely to occur.

For this reason, it is necessary to create a flow of processing fluid to effectively discharge such residual liquid, particularly in the upper discharge flow path 18a that discharges liquid that has entered the gap between the substrate S and the support tray 15. Therefore, in the upper discharge flow path 18a of this embodiment, the opening height H is made relatively small in the end regions Re at both ends in the width direction (X direction) at the connection CP between the upstream portion 181 and the buffer space 182, thereby increasing the pressure loss in the flow path. On the other hand, in the central region Rc, the opening height H is increased so that the pressure loss decreases toward the center. Therefore, the flow of processing fluid from the upstream portion 181 toward the buffer space 182 behaves as follows.

Figure 7 is a diagram showing the flow of processing fluid near the partition. More specifically, Figure 7(a) is a diagram showing the flow of processing fluid in the upper discharge flow path 18a, and Figure 7(b) is a diagram showing the flow of processing fluid flowing from the upstream portion 181 into the buffer space 182. In these figures, dashed arrows show the flow of processing fluid. The density of the arrows shows the flow rate, and the length shows the flow velocity.

As shown in Figures 7(a) and 7(b), at the connection CP between the upstream portion 181 and the buffer space 182, the pressure loss of the flow path is high at both ends and low in the center, so the flow that flows into the buffer space 182 through the center is dominant. In other words, the flow velocity and flow rate of the processing fluid are higher in the center than at the ends. This has the following two effects.

First, as shown in FIG. 7(a), in the upstream portion 181 of the upper discharge flow path 18a, a stronger flow is created in the center of the width direction (X direction) of the upper surface 151 of the support tray 15 than on the outer sides. This promotes the discharge of residual liquid that has entered the gap between the substrate S and the support tray 15.

Secondly, as shown in FIG. 7(b), the processing fluid flowing into the buffer space 182 forms a flow from the center toward both ends, i.e., the downstream portion 185, so that the processing fluid is discharged smoothly from the buffer space 182. This makes it 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.

In this way, in the first embodiment, a V-shaped notch is provided in the partition 112 separating the upstream portion 181 of the upper discharge flow path 18a from the buffer space 182, so that the partition 112 functions as a "straightening portion" that straightens the flow of the processing fluid. Of the effects obtained by this, the second effect is also discussed in Patent Document 1, but the first effect is not mentioned.

Note that, since the lower discharge channel 18b discharges processing fluid that does not directly touch the substrate S, the same rectifying function as the upper discharge channel 18a is essentially unnecessary. Therefore, as shown in FIGS. 5, 6, etc., the tip of the partition wall 122 may be configured to be in a straight line in the X direction. In addition, as described in Patent Document 1, for the purpose of adjusting the balance between the flow of processing fluid flowing into the buffer space 186 from the upstream section 185 and the flow of processing fluid in the buffer space 183, an appropriate switch is made. A notch may be provided.

Figure 8 is a diagram illustrating 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 that have substantially the same functions as those shown in Figures 5 and 6 are given the same reference numerals and detailed descriptions are omitted.

The second embodiment differs greatly from the first embodiment in the configuration of the flow straightening section. That is, 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 a "flow straightening section." In contrast, in the second embodiment, independent partition flow straightening members 191 and 192 are detachable from the first member 11 and the second member 12, respectively.

As shown in FIG. 8, the partition wall rectifying member 191 is an angular member having a substantially L-shaped cross section. A substantially V-shaped notch portion 191a is provided at the center in the width direction of the blade portion extending in the (-Y) direction among the two blade portions constituting the partition wall rectifying member 191. Then, the other wing portion is fixed to the first member 11 by the fixing screw 113a in a state in which it is brought into close contact with the recess 101a of the first member 11. Thereby, the partition wall rectifying member 191 exhibits a partition wall function and a flow straightening function similarly to the partition wall 112 of the first embodiment. Similarly, a partition wall rectifying member 192 is fixed to the lower part of the opening 101b by fixing screws 123a, and functions as a partition wall.

In this way, in the second embodiment, since the partition wall rectifying members 191 and 192 are detachable, it is possible to use the partition wall rectifying members 191 and 192 that correspond to the type of substrate S, processing conditions, and the like. For example, as described below, a plurality of partition wall flow regulating members 191 having different shapes and sizes of the notch portions 191a can be prepared in advance. Then, a partition wall rectifying member 191 suitable for the type of substrate S, processing conditions, etc. can be selected from among them and installed in the processing chamber 100. Thereby, it is possible to deal with a wide variety of substrates S, processing conditions, etc., and the versatility of the substrate processing apparatus 1 can be increased.

Figures 9 and 10 are diagrams illustrating other configurations of the straightening section. In the partition 112 of the first embodiment and the partition 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 difference between these shapes can be unambiguously shown by the change in opening height H with respect to the X direction position, so here the shapes are shown by a graph showing the relationship between the X direction position and opening height H.

In the example shown in FIG. 9A, there is no section where the opening height H is constant at both ends, and the opening height H increases continuously from both ends toward the center. With such a configuration, it is also possible to form a flow path in which the pressure loss decreases from the ends toward the center, and the same effects as in the above embodiment can be obtained.

In other words, the cross-sectional shape of the flow path may be such that the pressure loss is relatively large at both ends of the flow path and decreases toward the center. For example, if the opening height H is A shape that monotonically increases in a broad sense is preferable. Examples of this include, for example, as shown on the left in FIG. 3, there is a section in which the opening height H is constant at both ends, and in a strictly monotonous manner, the opening height H changes over the entire area as shown in FIG. 9(a). Both examples of increase may be included. This also applies to various shapes illustrated below.

Furthermore, as shown in FIGS. 9(b) and 9(c), the change in opening height H may be curved. In this case, the height may change only in the center as shown in FIG. 9(b), or the opening height H may change continuously over the entire area in the X direction as shown in FIG. 9(c). It may be an aspect. The shape of the curve can be set in various ways depending on the purpose, and for example, it may be linearly approximated for each section. Furthermore, in the embodiment shown in FIG. 9(d), the opening height H changes stepwise. Even with such a shape, a flow path can be formed in which the pressure loss is large at both ends and the pressure loss is smaller at the center.

Furthermore, as shown in FIG. 10, by devising the repeatedly provided uneven shape, it is possible to form a flow path in which the pressure loss when viewed macroscopically is small at the center and large at both ends. In the example shown in FIG. 10(a), unevenness in which the opening height H changes by a certain amount appears multiple times in the X direction, and at least one of the width of the recess and the width of the protrusion varies depending on the position in the X direction. different. In this case, microscopically, areas with high pressure loss and areas with low pressure loss appear alternately, but if you look at the flow of the processing fluid macroscopically, as shown by the dotted line, the pressure drop is lower in the center of the flow path. can be said to be formed. Furthermore, in the example shown in FIG. 10(b), the height difference of the unevenness that is 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 decreases toward the center when viewed macroscopically, as in the example of FIG. 10(a).

As explained above, in the first and second embodiments, the processing chamber 100, which is mainly composed of the first to third members 11 to 13, functions as the "processing vessel" of the present invention. Among 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.

In the above embodiment, the upstream portion 181, the buffer space 182, and the downstream portion 183 correspond to the "upstream portion," the "buffer space," and the "downstream portion" of the "upper discharge flow path" in the present invention, respectively. In addition, the upstream portion 185, the buffer space 186, and the downstream portion 187 correspond to the "upstream portion," the "buffer space," and the "downstream portion" of the "lower discharge flow path" in the present invention, respectively.

Further, in the first embodiment, the partition wall 112 functions as the "straightening section" of the present invention, while in the second embodiment, the partition wall straightening member 191 functions as the "wall straightening member" and the "straightening section" of the present invention. ing. Further, in the above embodiment, the opening height H corresponds to the "opening dimension" of the present invention. Furthermore, in the above embodiment, 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.

Note that the present invention is not limited to the embodiments described above, and various changes other than those described above can be made without departing from the spirit thereof. For example, in the embodiment described above, the side surface of the lid member 14 that opens and closes the opening 101 of the processing chamber 100 constitutes a part of the discharge flow path, but the present invention is applicable even if the structure is not like this. . For example, similar to the introduction-side flow path 17 in this embodiment, a discharge flow path may be formed in advance within the processing chamber.

In the above embodiment, the shape of the cutout in the partition wall 112 is symmetrical with respect to the center position Xc. However, the cutout shape may be asymmetrical. In the modified example shown in Figures 10(a) and 10(b), the cutout is arranged so that the opening height H is maximum at the center position Xc of the flow path. However, even if the opening height H is small at position Xc, it is possible to make the pressure loss smaller in the center when viewed macroscopically by increasing the opening height H around it.

Furthermore, in this embodiment, the processing fluid is supplied to the processing space SP from the side opposite to the opening 101 and is discharged toward the opening 101. However, this flow direction may also be reversed.

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

As described above by illustrating specific embodiments, in the substrate processing apparatus according to the present invention, for example, the rectifying section extends the discharge channel along the first direction from the center toward both ends. A configuration in which the pressure loss monotonically increases in a broad sense may be used. According to such a configuration, the flow of the processing fluid discharged from the processing space can be made stronger at the center than at both ends in the first direction. Thereby, it is possible to effectively promote the discharge of the processing fluid that has entered between the substrate and the support tray.

A specific configuration for realizing this may be such that the opening size of the discharge flow path along the first direction decreases monotonically in a broad sense from the center toward both ends. Alternatively, the opening size may decrease monotonically in a narrow sense in a central region within a predetermined distance from the center of the discharge channel in the first direction, and the opening size may be constant outside the central region. According to such a configuration, the pressure loss is high in the narrow portion of the opening and low in the wide portion, so it is suitable as a configuration for realizing the present invention.

The substrate processing apparatus according to the present invention may also be configured such that an opening is provided on the side of the processing vessel that connects the processing space with the outside space, and the apparatus further includes a lid that opens and closes the opening, and the support tray is attached to the surface of the lid that covers the opening. In this case, when the support tray is housed in the processing space, the space sandwiched between the ceiling surface of the inner wall surface of the processing vessel facing the processing space and the upper surface of the support tray can form the upstream portion. With this configuration, the flow of processing fluid in the processing space can be separated into upper and lower sides by the support tray, and these can be discharged separately as they are.

In this case, the processing container is provided with a first cavity serving as a processing space and a second cavity serving as a buffer space in communication with each other, and a partition is provided between the first cavity and the second cavity. A partition wall may be further provided, and in such a configuration, the gap between the lid portion and the partition wall constitutes a connecting portion, and it becomes possible for the partition wall to function as a rectifying portion.

Furthermore, the partition may be a partition straightening member that is detachably attached to the processing vessel. While the processing vessel is required to have high rigidity as a high-pressure vessel, the partition requires precision machining. Therefore, by making these separate members, it becomes possible to manufacture them using appropriate manufacturing methods. Also, since it becomes possible to replace only the partition straightening member, the workability of maintenance and repair is improved. Moreover, by replacing partition straightening members of different shapes, the device can be made highly versatile and applicable to various purposes.

For example, the lower discharge flow path, which discharges the processing 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 flow path cross-section whose 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 flow path cross-sectional area larger than that of 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.

With this configuration, the processing fluid that has passed under the support tray can be discharged separately from the processing fluid that has passed over the top of 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 flow path does not require the function of discharging the processing fluid that has entered between the substrate and the support tray, the straightening section provided in the upper discharge flow path is essentially unnecessary.

This invention can be applied to substrate processing techniques in general, in which a substrate is processed with a processing fluid in a processing vessel. In particular, it can be applied to processing using high-pressure fluids, such as substrate drying processing in which a substrate, such as a semiconductor substrate, is dried with a supercritical fluid.

REFERENCE SIGNS LIST 1 Substrate processing apparatus 14 Lid member 15 Support tray 18 Discharge flow path 18a Upper discharge flow path 18b Lower discharge flow path 55 Fluid discharge section 57 Fluid supply section 100 Processing chamber (processing vessel)
101 Opening 110 Cavity (first cavity)
111, 121 Recess (second cavity)
112 Partition wall (flow straightening section)
181, 185 Upstream portion 182, 186 Buffer space 183, 187 Downstream portion 191 Partition wall flow straightening member H Opening height (opening dimension)
Rc: central region; Re: end region; S: substrate; SP: processing space; X: first direction; Y: second direction.

Claims (8)

a flat support tray that supports a 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 side of the processing space;
a fluid discharge section that discharges the processing fluid via a discharge flow path provided in communication with the processing space at the other end opposite to the one end across the substrate;
Among the directions perpendicular to the flow direction of the processing fluid, a direction parallel to the main surface of the substrate is defined as a first direction, and a direction perpendicular to the flow direction and the first direction is defined as a second direction,
The discharge channel is provided to separately discharge the processing fluid that has passed above the substrate and the processing fluid that has passed below the support tray, and among them, the processing fluid that has passed above the substrate is discharged. In the upper discharge flow path,
an upstream portion that communicates with the processing space above the substrate and has a flow path cross section in which an opening dimension along the first direction is larger than an opening dimension along the second direction;
a buffer space that communicates with the upstream section and has a larger flow path cross-sectional area than the upstream section;
a downstream portion that connects a pair of openings provided at both ends of the buffer space in the first direction and the fluid discharge portion;
A substrate processing apparatus, comprising: a rectifying section that is provided at a connection between the upstream section and the buffer space and makes pressure loss at the center in the first direction lower than pressure loss at both ends. 2 . The substrate processing apparatus according to claim 1 , wherein in the rectifying section, pressure loss in the discharge flow path monotonically increases in a broad sense along the first direction from the center portion toward the both end portions. 3 . The substrate processing apparatus according to claim 2 , wherein in the rectifying section, an opening size of the discharge flow path along the second direction decreases monotonically in a broad sense from the center portion toward the both ends. The substrate processing apparatus according to claim 3, wherein in the flow straightening section, the opening size decreases monotonically in a narrow sense in a central region within a predetermined distance from the center of the discharge flow path in the first direction, and the opening size is constant outside the central region. An opening that communicates the processing space with an external space is provided on a side surface of the processing container,
further comprising a lid part for opening and closing the opening,
The support tray is attached to a surface of the lid portion that covers the opening,
In a state in which the support tray is housed in the processing space, a space sandwiched between a ceiling surface of the inner wall surface of the processing container facing the processing space and the upper surface of the support tray forms the upstream portion; A substrate processing apparatus according to any one of claims 1 to 4. In the processing container, a first cavity serving as the processing space and a second cavity serving as the buffer space are provided in communication with each other, and a space between the first cavity and the second cavity is provided. A partition wall is further provided to separate the
The substrate processing apparatus according to claim 5, wherein a gap between the lid portion and the partition wall constitutes the connection portion, and the partition wall functions as the rectification portion. 7. The substrate processing apparatus according to claim 6, wherein the partition wall is a partition wall rectifying member detachably provided to the processing container. Among the discharge flow paths, a lower discharge flow path that discharges the processing fluid that has passed under the support tray includes:
an upstream portion that is in communication with the processing space below the support tray and has a flow path cross section in which an opening dimension along the first direction is larger than an opening dimension along the second direction;
a buffer space communicating with the upstream portion and having a flow path cross-sectional area larger than that of the upstream portion;
5 . The substrate processing apparatus according to claim 1 , further comprising a downstream portion connecting a pair of openings provided at both ends of said buffer space in said first direction to said fluid discharge portion.

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