JP7583546B2 - Substrate Processing Equipment - Google Patents

Description

This invention relates to a substrate processing apparatus that processes a substrate by immersing the substrate in a processing liquid, such as a chemical solution or pure water, stored in a processing tank and supplying air bubbles to the substrate in the processing liquid.

In the field of semiconductor device manufacturing, there is a demand for technology to form recesses with high aspect ratios to accommodate the increasing density and capacity of semiconductor devices. For example, the manufacturing process of a three-dimensional NAND nonvolatile semiconductor device (hereinafter referred to as "3D-NAND memory") includes a process of forming recesses in the stacking direction in a multi-layer structure of silicon oxide films (SiO2 films) and silicon nitride films (SiN films), and then removing the SiN films through the recesses by wet etching. To carry out this process, the use of a substrate processing apparatus, for example, as described in Patent Document 1, is being considered.

When the above wet etching is performed using a substrate processing apparatus, a chemical solution containing phosphoric acid, which is an example of an etchant for a SiN film, is used as the processing liquid. More specifically, in the substrate processing apparatus, a jet pipe is disposed at the inner bottom of a storage space formed inside a processing tank, and the processing liquid is supplied from the jet pipe to the storage space. Therefore, in the processing tank, a certain amount of the processing liquid is stored in the processing tank while overflowing from the processing tank. Then, a substrate having the above recess structure is immersed in the processing liquid stored in the processing tank. In addition, in the substrate processing apparatus, a bubble supply pipe is disposed at the inner bottom of the storage space, similar to the jet pipe, and bubbles are supplied from the inner bottom of the storage space toward the overflow surface. These bubbles rise in the processing liquid and are supplied to the substrate. By supplying bubbles to the substrate in this way, fresh processing liquid can be rapidly and continuously supplied to the recess.

JP 2016-200821 A JP 2003-40649 A JP 2009-98270 A

Patent Document 1 does not describe the detailed structure of the bubble supply pipe, but in substrate processing equipment, a porous material finished into a pipe shape (Patent Document 2) or a cylindrical member with a row of multiple through holes at regular intervals (Patent Document 3) is often used as a bubble supply pipe. When a gas such as nitrogen gas is supplied from a gas supply source to these bubble supply pipes, the gas is discharged from multiple openings (porous holes or through holes) provided on the surface of the bubble supply pipe, thereby supplying bubbles into the processing liquid. The size of the bubbles supplied in this way is larger than the opening size. This is because the bubbles are supplied as follows. That is, immediately after the bubbles are generated, the bubbles adhere to the periphery of the opening on the surface of the bubble supply pipe. Then, after the adhesion area spreads radially from the opening as time passes, the bubbles leave the opening and adhesion area of the bubble supply pipe and are supplied into the processing liquid.

Thus, in conventional technology, the bubble size becomes larger than the dimensions of the opening that functions as the bubble outlet, making it difficult to effectively supply fresh processing liquid to the substrate surface by supplying bubbles. In addition, in the substrate processing apparatuses described in Patent Documents 1 and 3, multiple substrates are processed simultaneously while being spaced apart by a fixed distance, making it difficult for bubbles to get between the substrates. Therefore, conventional substrate processing apparatuses have certain limitations in terms of improving the quality of substrate processing.

This invention has been made in consideration of the above problems, and aims to reduce the bubble size and improve processing quality in a substrate processing apparatus that immerses a substrate in a processing liquid stored in a processing tank and supplies air bubbles to the substrate in the processing liquid for processing.

A first aspect of the present invention is a substrate processing apparatus comprising: a processing tank having a storage space for storing a processing liquid, for processing a substrate by immersing the substrate in the processing liquid stored in the storage space; a substrate holding section for holding the substrate in an upright position within the storage space; a processing liquid discharge section provided below the substrate held in the substrate holding section and for discharging the processing liquid into the storage space to form a flow of the processing liquid within the storage space; and a piping provided below the substrate held in the substrate holding section within the storage space, and a bubble supply section having a hollow protruding portion having a columnar shape protruding from the piping in the direction of the flow of the processing liquid, and discharging gas sent through the protruding portion via the piping from a bubble discharge port provided in the center of a tip of the protruding portion to supply bubbles into the processing liquid stored in the storage space.
A second aspect of the present invention is a substrate processing apparatus comprising: a processing tank having a storage space for storing a processing liquid, for processing a substrate by immersing the substrate in the processing liquid stored in the storage space; a substrate holding section for holding the substrate in an upright position within the storage space; a processing liquid discharge section provided below the substrate held in the substrate holding section and for discharging the processing liquid into the storage space to form a flow of the processing liquid within the storage space; and a pipe provided below the substrate held in the substrate holding section within the storage space, and a bubble supply section having a hollow protruding portion protruding from the pipe in the direction of the flow of the processing liquid and having a tapered shape with an outer diameter dimension decreasing toward its tip, and discharging gas sent through the protruding portion via the pipe from a bubble discharge port provided at the tip of the protruding portion to supply bubbles into the processing liquid stored in the storage space.

As described above, according to the present invention, the bubble outlet of the bubble supply section is provided not in the pipe, but at the tip of the protruding section that protrudes from the pipe. Therefore, the contact area of the bubble supply section where the bubbles are in contact until just before they leave the bubble outlet and are supplied to the processing liquid is limited to the tip surface of the protruding section, and can be made narrower than when the bubble outlet is provided on the side wall of the pipe. As a result, the bubble size can be reduced, improving processing quality.

1 is a plan view showing a schematic configuration of a substrate processing system equipped with a substrate processing apparatus according to a first embodiment of the present invention; 1 is a schematic diagram showing a schematic configuration of a first embodiment of a substrate processing apparatus according to the present invention; 3 is an exploded perspective view showing a schematic diagram of a main configuration of the substrate processing apparatus shown in FIG. 2; FIG. 3 is a partial cross-sectional view of FIG. 2 . 11 is a schematic diagram showing the positional relationship between a plurality of substrates held by a lifter and a bubble discharge port. FIG. FIG. 11 is a schematic diagram showing a comparative example of the substrate processing apparatus according to the first embodiment; 13 is a diagram showing a configuration of a bubble supplying unit used in a second embodiment of a substrate processing apparatus according to the present invention; FIG. 13A and 13B are diagrams showing other configurations of the air bubble supplying unit.

Figure 1 is a plan view showing the schematic configuration of a substrate processing system equipped with a first embodiment of a substrate processing apparatus according to the present invention. The substrate processing system 1 includes a container placement unit 2, a shutter drive mechanism 3, a substrate transfer robot 4, a posture conversion mechanism 5, a pusher 6, a substrate transport mechanism 7, a processing unit 8, and a control unit 9. In order to unify the directions in the following figures, XYZ orthogonal coordinate axes are set as shown in Figure 1. Here, the XY plane represents the horizontal plane. The Z axis represents the vertical axis, and more specifically, the Z direction is the vertical direction.

A storage container that stores substrates W is placed on the storage container placement section 2. In this embodiment, a FOUP F that is configured to store multiple (e.g., 25) horizontally oriented substrates W stacked in the Z direction is used as an example of a storage container. The FOUP F is placed on the storage container placement section 2 with unprocessed substrates W stored therein, or it is placed on the storage container placement section 2 empty to store processed substrates W. In this embodiment, the substrates W stored in the FOUP F are semiconductor wafers that form 3D-NAND memories, and have high aspect ratio recesses.

In the process space adjacent to the container placement unit 2 on the (+Y) side, a shutter drive mechanism 3, a substrate transfer robot 4, a posture conversion mechanism 5, a pusher 6, a substrate transport mechanism 7, and a processing unit 8 are arranged. The container placement unit 2 and the process space are partitioned by a partition wall (not shown) equipped with a shutter 31 that can be opened and closed. The shutter 31 is connected to the shutter drive mechanism 3. The shutter drive mechanism 3 closes the shutter 31 in response to a close command from the control unit 9 to spatially separate the container placement unit 2 and the process space. Conversely, the shutter drive mechanism 3 opens the shutter 31 in response to an open command from the control unit 9 to connect the container placement unit 2 and the process space. This makes it possible to carry an unprocessed substrate W from the FOUP F into the process space and to carry a processed substrate W out to the FOUP F.

The above-mentioned loading and unloading process of the substrates W is performed by the substrate transfer robot 4. The substrate transfer robot 4 is configured to be freely rotatable in a horizontal plane. The substrate transfer robot 4 transfers multiple substrates W between the posture conversion mechanism 5 and FOUP F with the shutter 31 open. In addition, the posture conversion mechanism 5 converts the posture of the multiple substrates W between an upright posture and a horizontal posture after receiving the substrates W from FOUP F via the substrate transfer robot 4 or before transferring the substrates W to FOUP F.

The pusher 6 is disposed on the substrate transport mechanism 7 side of the attitude change mechanism 5 (the +X direction side in the figure), and transfers multiple substrates W in an upright position between the attitude change mechanism 5 and the substrate transport mechanism 7. The substrate transport mechanism 7 also moves horizontally from a position facing the pusher 6 as shown in the figure (hereinafter referred to as the "standby position") along the arrangement direction (Y direction in the figure) in which the processing sections 81 to 85 that make up the processing unit 8 are arranged.

The substrate transport mechanism 7 includes a pair of suspension arms 71. The pair of suspension arms 71 can be swung to hold or release a plurality of substrates W collectively. More specifically, the lower edges of the arms 71 swing about a horizontal axis in a direction away from each other to release the substrates W, and the lower edges of the arms 71 swing about a horizontal axis in a direction approaching each other to clamp and hold the substrates W. Although not shown in FIG. 1, the substrate transport mechanism 7 includes an arm moving unit and an arm swinging unit. Of these, the arm moving unit has the function of moving the pair of suspension arms 71 horizontally along the arrangement direction Y in which the processing units 81 to 85 are arranged. This horizontal movement positions the pair of suspension arms 71 at positions facing each of the processing units 81 to 85 (hereinafter referred to as "processing positions") and at a standby position.

On the other hand, the arm swinging section has a function of executing the arm swinging operation, and switches between a holding state in which the substrate W is clamped and held, and a release state in which the substrate W is released from the clamped state. Therefore, by this switching operation and the up and down movement of the lifter 810a functioning as the substrate holding section of the processing sections 81 and 82 and the lifter 810b functioning as the substrate holding section of the processing sections 83 and 84, the substrate W can be transferred between the lifter 810 and the suspended arm 71. Also, at the processing position facing the processing section 85, the substrate W can be transferred between the processing section 85 and the suspended arm 71. Furthermore, at the standby position, the substrate W can be transferred between the posture conversion mechanism 5 and the suspended arm 71 via the pusher 6.

As described above, the processing unit 8 is provided with five processing sections 81 to 85, which function as the first chemical processing section 81, the first rinsing processing section 82, the second chemical processing section 83, the second rinsing processing section 84, and the drying processing section 85. Of these, the first chemical processing section 81 and the second chemical processing section 83 each store the same or different chemical liquid in the processing tank 821, and immerse multiple substrates W in the chemical liquid at once to perform chemical processing. The first rinsing processing section 82 and the second rinsing processing section 84 each store a rinsing liquid (e.g., pure water) in the processing tank 821, and immerse multiple substrates W in the rinsing liquid at once to perform rinsing processing on the surfaces. These first chemical processing section 81, the first rinsing processing section 82, the second chemical processing section 83, and the second rinsing processing section 84 correspond to the first embodiment of the substrate processing apparatus according to the present invention, and although the types of processing liquids are different, the basic configuration of the apparatus is the same. The device configuration and operation will be described in detail later with reference to Figures 2 to 5.

As shown in FIG. 1, the first chemical processing unit 81 and the adjacent first rinse processing unit 82 are paired, and the second chemical processing unit 83 and the adjacent second rinse processing unit 84 are paired. The lifter 810a not only functions as the "substrate holder" of the present invention in the first chemical processing unit 81 and the first rinse processing unit 82, but also functions as a dedicated transport mechanism for transferring the substrate W that has been chemically processed in the first chemical processing unit 81 to the first rinse processing unit 82. The lifter 810b not only functions as the "substrate holder" of the present invention in the second chemical processing unit 83 and the second rinse processing unit 84, but also functions as a dedicated transport mechanism for transferring the substrate W that has been chemically processed in the second chemical processing unit 83 to the second rinse processing unit 84.

In the processing unit 8 configured in this manner, the three support members (reference numeral 812 in FIG. 2) of the lifter 810a receive multiple substrates W from a pair of suspension arms 71 of the substrate transport mechanism 7 all at once, and while performing an overflow process in which the processing liquid overflows from the processing tank and an air bubble supply process in which air bubbles are supplied into the processing liquid stored in the processing tank, as described in detail later, the lifter 810a lowers the support members holding the multiple substrates W from the chemical liquid, moves them laterally to the first rinse processing unit 82, and further lowers the support members holding the chemically processed substrates W into the processing tank (reference numeral 821 in FIG. 2) of the first rinse processing unit 82 and immerses them in the rinse liquid. After waiting for a predetermined rinsing time, the lifter 810a raises the support member while holding the rinsed substrate W, lifting the substrate W out of the rinsing liquid. After this, multiple substrates W are collectively transferred from the support member of the lifter 810a to a pair of suspension arms 71 of the substrate transport mechanism 7.

Similarly, the lifter 810b also receives multiple substrates W from a pair of suspension arms 71 of the substrate transport mechanism 7 in a lump, and lowers the multiple substrates W into the treatment tank 821 of the second chemical processing unit 83 to immerse them in the chemical solution. After waiting for a predetermined chemical processing time, the lifter 810b raises the support member to lift the multiple substrates W that have been treated with the chemical solution from the chemical solution, moves the support member laterally to the treatment tank of the second rinse processing unit 84, and further lowers the support member into the treatment tank 821 of the second rinse processing unit 84 to immerse them in the rinse solution. After waiting for a predetermined rinse processing time, the second lifter 810b raises the support member to lift the substrates W from the rinse solution. After this, the multiple substrates W are handed over from the second lifter 810b to the substrate transport mechanism 7 in a lump. Each of the first chemical processing unit 81, the first rinsing processing unit 82, the second chemical processing unit 83, and the second rinsing processing unit 84 may be provided with a lifter that functions as the "substrate holder" of the present invention, while the substrate W may be loaded and unloaded from the processing units 81 to 84 by the substrate transport mechanism 7 or a dedicated transport mechanism.

The drying processing section 85 has a substrate holding member (not shown) capable of holding multiple (e.g., 52) substrates W arranged in an upright position, and dries the substrates W by supplying an organic solvent (such as isopropyl alcohol) to the substrates W in a reduced pressure atmosphere and by shaking off liquid components on the surface of the substrate W using centrifugal force. The drying processing section 85 is configured to be able to transfer substrates W between a pair of suspended arms 71 of the substrate transport mechanism 7. The drying processing section 85 then receives multiple substrates W after rinsing all at once from the substrate transport mechanism 7, and performs a drying process on the multiple substrates W. After the drying process, the multiple substrates W are transferred all at once from the substrate holding member to the substrate transport mechanism 7.

Next, the substrate processing apparatus according to the present invention will be described. The first chemical processing unit 81, the first rinsing processing unit 82, the second chemical processing unit 83, and the second rinsing processing unit 84 provided in the substrate processing system shown in FIG. 1 use different processing liquids, but the configuration and operation of the apparatus are basically the same. Therefore, in the following, the configuration and operation of the first chemical processing unit 81, which corresponds to the first embodiment of the substrate processing apparatus according to the present invention, will be described, and descriptions of the first rinsing processing unit 82, the second chemical processing unit 83, and the second rinsing processing unit 84 will be omitted.

Figure 2 is a schematic diagram showing the outline of the first embodiment of the substrate processing apparatus according to the present invention. Figure 3 is an exploded perspective view showing the main configuration of the substrate processing apparatus shown in Figure 2. Figure 4 is a partial cross-sectional view of Figure 2. Figure 5 is a schematic diagram showing the arrangement relationship between multiple substrates held by a lifter and a bubble discharge port. The first chemical processing unit 81 is an apparatus that uses a chemical solution containing, for example, phosphoric acid as a processing solution to etch away a silicon nitride film through a recess formed on the surface of the substrate W. As shown in Figures 2 and 3, the first chemical processing unit 81 is provided with a processing tank 821 for performing a first chemical processing on the substrate W. The processing tank 821 has an upwardly opening box structure composed of a bottom wall 821a that is rectangular in plan view and four side walls 821b to 821e that rise from the periphery of the bottom wall 821a. Therefore, the processing tank 821 can immerse multiple substrates W held by the lifter 810a at once while storing the processing liquid in a storage space 821f surrounded by the bottom wall 821a and the side walls 821b to 821e. In addition, the processing tank 821 has an upper opening 821g that opens in the (+Z) direction, allowing the processing liquid to overflow from the storage space 821f.

An overflow tank 822 is provided around the treatment tank 821, and a recovery space 822a for recovering overflowed treatment liquid is formed between the overflow tank 822 and side walls 821b to 821e of the treatment tank 821. An outer container 823 is provided to surround the lower and sides of the treatment tank 821 and the overflow tank 822.

A flow piping system 839 is disposed in a part of the recovery space 822a of the overflow tank 822, more specifically, in the space on the (-X) direction side of the side wall 821d. The inlet of the flow piping system 839 is connected to the treatment liquid supply unit 832, and the outlet is connected to the flow pipe 831 of the treatment liquid discharge unit 830. Therefore, when the treatment liquid supply unit 832 operates in response to a treatment liquid supply command from the control unit 9, the treatment liquid is simultaneously supplied to the multiple flow pipes 831 via the flow piping system 839. As a result, the treatment liquid is discharged from the flow pipe 831 and stored in the storage space 821f. The detailed configuration of the flow pipe 831 will be described later.

In addition, the processing liquid that overflows from the processing tank 821 is collected in the overflow tank 822. A processing liquid collection unit 833 is connected to this overflow tank 822. When the processing liquid collection unit 833 operates in response to a processing liquid collection command from the control unit 9, the processing liquid collected in the overflow tank 822 is sent via the processing liquid collection unit 833 to the processing liquid supply unit 832 for reuse. In this way, in this embodiment, the processing liquid can be stored in the storage space 821f while being circulated and supplied to the processing tank 821.

2, a lifter 810a is provided to immerse multiple substrates W in a storage space 821f in which the processing liquid is stored while holding them together. The lifter 810a is configured to be able to move up and down between a "delivery position" where multiple substrates W are delivered to and from the substrate transport mechanism 7 (FIG. 1) and the storage space 821f. The lifter 810a includes a back plate 811, three support members 812, and an extension member 813. The back plate 811 extends toward the bottom wall 821a along the side wall 821b of the processing tank 821. The support member 812 extends in the (-X) direction from the lower end side surface of the back plate 811. In this embodiment, three support members 812 are provided. In each support member 812, multiple V-shaped grooves 812a are arranged at a constant pitch in the X direction. Each groove 812a is a V-shaped groove 812a that is slightly wider than the thickness of the substrate W and opens in the (+Z) direction, making it possible to lock the substrate W. Therefore, the three support members 812 can collectively hold multiple substrates W transported by the substrate transport mechanism 7 at a constant substrate pitch PT (FIG. 5). The extension member 813 extends in the (+X) direction from the rear surface of the upper end of the back plate 811. The lifter 810a is L-shaped overall, as shown in FIG. 2. The uppermost position of the lifter 810a is set to a height that allows the substrate transport mechanism 7 to pass above the support members 812 even when the substrate transport mechanism 7 is holding multiple substrates W.

A lifter drive mechanism 814 is provided on the (+X) direction side of the processing tank 821. The lifter drive mechanism 814 includes a lift motor 815, a ball screw 816, a lift base 817, a lift column 818, and a motor drive unit 819. The lift motor 815 is attached to the frame (not shown) of the substrate processing system 1 with the rotation shaft vertically placed. The ball screw 816 is connected to the rotation shaft of the lift motor 815. One side of the lift base 817 is screwed to the ball screw 816. The base end side of the lift column 818 is attached to the center of the lift base 817, and the other end side is attached to the underside of the extension member 813. When the motor drive unit 819 drives the lift motor 815 in response to a lift command from the control unit 9, the ball screw 816 rotates, and the lift column 818 rises together with the lift base 817. This positions the support member 812 at the transfer position. Furthermore, when the motor drive unit 819 drives the lift motor 815 in the reverse direction in response to a lowering command from the control unit 9, the ball screw 816 rotates in the reverse direction, and the lift column 818 lowers together with the lift base 817. As a result, the multiple substrates W held by the support member 812 are immersed collectively in the processing liquid stored in the storage space 821f.

In the storage space 821f, a processing liquid discharge unit 830 and a bubble supply unit 840 are disposed below the multiple substrates W held by the support member 812, i.e., on the (-Z) direction side. The processing liquid discharge unit 830 discharges the processing liquid supplied from the processing liquid supply unit 832 via a flow piping system 839 into the storage space 821f, and the bubble supply unit 840 supplies nitrogen gas bubbles V (Figure 5) into the processing liquid stored in the storage space 821f, and each is configured as follows.

As shown in Figures 3 and 4, the treatment liquid discharge section 830 has a flow pipe 831 extending in the X direction. In this embodiment, four flow pipes 831 are arranged at a distance from each other in the Y direction. The (-X) end of each flow pipe 831 is connected to the outlet of the flow piping system 839, and the (+X) end is sealed. In addition, a plurality of treatment liquid discharge ports 834 are drilled in the side wall of each flow pipe 831 so as to be arranged in the X direction at regular intervals. In this embodiment, as shown in Figure 4, each treatment liquid discharge port 834 is provided in the (-Z) direction. Therefore, the treatment liquid supplied to the flow pipe 831 flows inside the pipe in the (+X) direction and is discharged from each treatment liquid discharge port 834 toward the bottom wall 821a, that is, the inner bottom surface 821h of the storage space 821f. The processing liquid then flows upward through the inner bottom surface 821h of the storage space 821f as shown by the solid arrow in Figure 4, forming a flow F of processing liquid from the bottom wall 821a of the processing tank 821 toward the upper opening 821g, i.e., the overflow surface. In this way, an upward flow of processing liquid is formed below the substrate W. To facilitate understanding of the invention, the one of the four flow tubes 831 located furthest from the (-Y) direction will be referred to as "flow tube 831a," and the ones successively located on the (+Y) direction side will be referred to as "flow tube 831b," "flow tube 831c," and "flow tube 831d," respectively. When no distinction is made between these, they will simply be referred to as "flow tube 831," as described above.

As shown in Figures 3 to 5, the bubble supply unit 840 has multiple (four in this embodiment) bubblers 841. Each bubbler 841 has a bubble pipe 842 extending in the X direction and multiple protruding parts 843 protruding upward from the bubble pipe 842, that is, in the (+Z) direction. One end of each bubble pipe 842 is connected to a gas supply unit 844 that supplies nitrogen gas, and the other end is sealed. The multiple protruding parts 843 are provided on the upper side wall of the bubble pipe 842 at the same pitch PT as the constant substrate pitch PT. Each protruding part 843 has a hollow cylindrical shape as shown in Figure 3, and a bubble outlet 845 is provided in the center of the upper end surface. In this embodiment, the bubble pipe 842 and the multiple protruding portions 843 are integrally formed by cutting and drilling the surface of a long resin pipe made of a resin material, particularly at least one selected from the group consisting of polyetheretherketone (PEEK), perfluoroalkoxyalkane (PFA), and polytetrafluoroethylene (PTFE). It goes without saying that the bubble pipe 842 and the multiple protruding portions 843 may be prepared separately, and the multiple protruding portions 843 may be attached to the bubble pipe 842 to be integrated.

In the bubble supply unit 840 configured in this manner, when the gas supply unit 844 supplies nitrogen gas to the bubble supply unit 840 in response to a bubble supply command from the control unit 9, the nitrogen gas flowing through the bubble piping 842 is discharged upward from the bubble outlet 845. As a result, nitrogen gas bubbles V are supplied to the processing liquid stored in the storage space 821f, and the bubbles V are supplied in a direction toward the overflow surface from a position higher than the processing liquid outlet 834 in the vertical direction Z, that is, in the (+Z) direction. These bubbles V rise in the processing liquid and promote the replacement of the processing liquid on the surface of the substrate W with fresh processing liquid. Note that the gas supply unit 844 may be configured to supply nitrogen gas from a cylinder filled with nitrogen gas, for example, or a utility provided in the factory in which the substrate processing system 1 is installed may be used.

4, the four bubblers 841 are supported from below by three bubbler boards 851, and are fixedly disposed below the substrate W held by the lifter 810a and above the processing liquid outlet 834. Again, to facilitate understanding of the invention, the one of the four bubblers 841 disposed furthest in the (-Y) direction will be referred to as "bubbler 841a," and those disposed successively in the (+Y) direction will be referred to as "bubbler 841b," "bubbler 841c," and "bubbler 841d," respectively. When no distinction is made between these, they will simply be referred to as "bubbler 841," as described above. Similarly, for the bubbler boards 851, the one arranged closest to the (-Y) direction is referred to as the "bubbler board 851a," and the ones arranged next to each other in the (+Y) direction are referred to as the "bubbler board 851b" and the "bubbler board 851c." Also, when there is no need to distinguish between these, they are simply referred to as the "bubbler board 851" as described above.

The bubbler boards 851a to 851c each have a plate shape extending in the X direction. As shown in FIG. 4, the bubbler board 851a is disposed between the flow pipes 831a and 831b at a position higher than the processing liquid outlet 834 in the vertical direction Z, and is fixed to the processing tank 821 by a fixing member (not shown). The bubbler 841a is fixed to the upper surface of the bubbler board 851a so as to satisfy the following arrangement relationship. As shown in FIG. 5, the arrangement relationship is that the protruding portion 843 attached to the bubbler 841a faces upward, and the substrate W and the bubble outlet 845 are alternately positioned in the X direction. By arranging them in this way, the bubbles V supplied from the bubble outlet 845 are discharged toward the gap between the adjacent substrates W in the X direction, and efficient chemical processing is performed. The same arrangement relationship applies to the other bubblers 841b to 841d.

The bubbler board 851b is disposed between the flow tubes 831b and 831c at a position higher than the treatment liquid outlet 834 in the vertical direction Z, and is fixed to the treatment tank 821 by a fixing member (not shown). Bubblers 841b and 841c are fixed to the upper surface of the bubbler board 851b at a fixed interval in the Y direction. The bubbler board 851c is disposed between the flow tubes 831c and 831d at a position higher than the treatment liquid outlet 834 in the vertical direction Z, and is fixed to the treatment tank 821 by a fixing member (not shown). The bubbler board 851c has a bubbler 841d fixed to the upper surface of the bubbler board 851c. In this way, the bubbler boards 851a to 851c have the function of supporting the bubble supply unit 840 from below.

In addition, the bubbler boards 851a to 851c are arranged between the flow pipes 831a to 831d at a position higher than the treatment liquid discharge port 834 in the vertical direction Z, so in addition to the above-mentioned support function, they have the function of regulating the flow F of the treatment liquid flowing upward via the inner bottom surface 821h of the storage space 821f. The bubbler boards 851a to 851c are spaced apart from each other to form through-holes 852a and 852b that serve as a flow path for the treatment liquid. The flow pipes 831b and 831c are arranged so that their lower ends enter the through-holes 852a and 852b. In addition, the flow pipe 831a is arranged on the (-Y) side of the bubbler board 851a at the same height as the flow pipes 831b and 831c, and the flow pipe 831d is arranged on the (+Y) side of the bubbler board 851a. Moreover, gaps 86 are formed between adjacent ones of the bubbler boards 851a to 851c and the flow tubes 831a to 831d. Therefore, the flow F of the treatment liquid (hereinafter referred to as the "liquid to be diverted") that flows toward the lower surface of the bubbler board 851 among the upward flow of the treatment liquid is restricted by the lower surface and is distributed within the horizontal plane. For example, in the partial enlarged view of FIG. 4, the flow F of the treatment liquid to be diverted toward the lower surface of the bubbler board 851c is diverted into a flow F5 of the treatment liquid that flows through the gap 86 between the bubbler board 851c and the flow tube 831c and a flow F6 of the treatment liquid that flows through the gap 86 between the bubbler board 851c and the flow tube 831d. Also, in the other bubbler boards 851a and 851b, as in the bubbler board 851c, the flow F of the treatment liquid to be diverted is restricted and diverted into a plurality of flows F1 to F4 of the treatment liquid.

In this embodiment, a flow F of a portion of the processing liquid (liquid to be diverted) flowing upward via the inner bottom surface 821h of the storage space 821f is diverted into multiple flows F1 to F6 and rises toward the overflow surface. In this embodiment, the bubbler boards 851a to 851c diverte at least a portion of the processing liquid flowing upward via the inner bottom surface 821h of the storage space 821f as the liquid to be diverted, and diverte the flow F of the liquid to be diverted into multiple ascending flows to guide them to the substrate W held by the lifter 810a, thereby functioning as a diverting section 850 (Figure 3).

The configuration of the first chemical processing unit 81, which corresponds to the first embodiment of the substrate processing apparatus according to the present invention, has been described with reference to Figures 2 to 5. The second chemical processing unit 83 also has the same configuration as the first chemical processing unit 81, except that the processing liquid is the same or a different type, and corresponds to the first embodiment of the substrate processing apparatus according to the present invention. The first rinse processing unit 82 and the second rinse processing unit 84 also have the same configuration as the first chemical processing unit 81, except that the processing liquid is a rinse liquid such as pure water or DIW (deionized water), and correspond to the first embodiment of the substrate processing apparatus according to the present invention.

As described above, in this embodiment, multiple protruding portions 843 are protruding upward from the bubble piping 842, and nitrogen gas is discharged from the bubble discharge ports 845 provided at the tip of each protruding portion 843 to supply bubbles V into the treatment liquid. This makes it possible to reduce the size of the bubbles V. The detailed reasons for this will be explained by comparing the comparative example shown in Figure 6 with this embodiment (Figure 5).

Figure 6 is a schematic diagram showing a comparative example of the substrate processing apparatus according to the first embodiment. In this comparative example, a bubble outlet 845 is provided on the side wall of the bubble pipe 842, and nitrogen gas is discharged from the bubble outlet 845 to supply bubbles V into the processing liquid. In this case, immediately after the generation of the bubbles V, the bubbles V adhere to the periphery of the bubble outlet 845 on the side wall surface of the bubble pipe 842. In this way, the region where the bubbles V adhere to the bubbler 841 (hereinafter referred to as the "adhesion region") spreads along the surface of the bubbler 841 over time, and the bubbles V grow into a relatively large, roughly dome-shaped shape, as shown in the partially enlarged view of Figure 6, for example. After that, the bubbles V leave the bubble outlet 845 and the adhesion region and are supplied into the processing liquid.

In contrast, in this embodiment, the bubble V adheres to the tip surface of the protruding portion 843 immediately after it is generated. Therefore, the adhesion area spreads radially from the bubble outlet 845 as time passes, but when it reaches the periphery of the tip surface (the tip step of the protruding portion 843), the spread of the adhesion area is restricted, for example, as shown in the enlarged partial view of FIG. 5. This stops the growth of the bubble V, and at this point the bubble V leaves the bubble outlet 845 and the adhesion area and is supplied into the processing liquid. Thus, in the first embodiment, the adhesion area to which the bubble V adheres until just before it is supplied into the processing liquid is limited to the tip surface of the protruding portion 843. As a result, in the first embodiment, the size of the bubble V is smaller than that of the comparative example (FIG. 6), and the processing quality can be improved.

In particular, since the first chemical processing unit 81 wet etches the SiN film through a recess with a high aspect ratio, applying the present invention to the first chemical processing unit 81 is important for the manufacture of 3D-NAND memories. That is, in order to improve wet etching performance, it is necessary to perform good replacement of the processing liquid between the inside and outside of the recess. In addition, silicon precipitation occurs near the bottom of the recess due to the etching reaction, but the silicon can be discharged from the recess by replacing the processing liquid. In order to stably and continuously realize this liquid replacement, it is necessary to increase the concentration difference between the inside and outside of the recess, that is, the concentration gradient. Furthermore, in order to satisfy these, it is an important technical matter to efficiently supply fresh processing liquid to the surface of the substrate W by reducing the bubble size. In this regard, according to the first chemical processing unit 81 that can effectively reduce the size of the bubble V, the bubble V promotes the supply of fresh processing liquid, and the SiN film can be wet etched well.

As shown in the partially enlarged view of FIG. 5, the bubbler 841d is arranged so that the substrates W and the bubble outlets 845 are alternately positioned in the X direction, so that small bubbles V can be efficiently supplied between adjacent substrates W. As a result, substrate processing (chemical processing and rinsing processing) can be performed with high quality.

In this way, in the first embodiment, the (+Z) direction corresponds to an example of the "flow direction of the treatment liquid" of the present invention. The bubble pipe 842 corresponds to an example of the "piping" of the present invention. The X direction corresponds to the "horizontal direction" of the present invention.

The present invention is not limited to the above-mentioned embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-mentioned embodiment, the bubbler 841 having the hollow cylindrical protruding portion 843 from the bubble pipe 842 is used to supply the bubbles V, but the configuration of the bubbler 841 is not limited to this. For example, as shown in FIG. 7, a hollow truncated cone-shaped protruding portion 846 protruding from the bubble pipe 842 may be used (second embodiment). According to this second embodiment, the surface area of the tip surface of the protruding portion 846 is narrower than that of the hollow cylindrical protruding portion 843 used in the first embodiment, and smaller bubbles V can be supplied. As a result, the substrate processing can be performed with even higher quality.

In the first and second embodiments, the tip surfaces of the protruding portions 843 and 846 are circular, but the shape is not limited to this and can be any shape. For example, as shown in FIG. 8, protruding portions 847 and 848 having elliptical tip surfaces may be used. In short, it is preferable to use protruding portions having a columnar shape or a tapered shape in which the outer diameter dimension decreases toward the tip.

In addition, plasma treatment may be performed on the tips of the protruding portions 843, 846 to 848. This plasma treatment makes the tips, i.e., the area around the bubble outlet 845, hydrophilic, facilitating the release of the bubbles V. As a result, the size of the bubbles V can be further reduced.

In the above embodiment, the processing liquid discharge unit 830 includes four flow pipes 831, but the number of flow pipes 831 is not limited to this number, and is preferably set according to the size of the storage space 821f and the substrate W, etc. The bubble supply unit 840 includes four bubblers 841, but the number of bubblers 841 is not limited to this number, and is preferably set according to the size of the storage space 821f and the substrate W, etc. The flow division unit 850 includes three bubbler boards 851, but the number of bubblers 841 is not limited to this number, and is preferably set according to the size of the storage space 821f and the substrate W, etc.

In the above embodiment, the bubbler 841 is supported by the bubbler board 851 of the flow dividing section 850 and fixedly disposed within the processing liquid stored in the storage space 821f, and the flow F of the processing liquid flowing upward via the inner bottom surface 821h is divided into multiple flows by the bubbler board 851. Here, for example, the present invention may be applied to a substrate processing apparatus in which the bubbler board 851 is directly fixed to the processing tank 821, that is, a flow dividing section 850 is not provided.

In addition, in the above embodiment, nitrogen gas is sent to the bubbler 841 to supply nitrogen gas bubbles V into the treatment liquid, but a gas other than nitrogen gas may be used as the "gas" of the present invention.

In the above embodiment, the present invention is applied to a substrate processing apparatus that discharges the processing liquid from the flow pipe 831 toward the inner bottom surface 821h of the storage space 821f, but the supply mode of the processing liquid of the present invention is not limited to this. For example, the present invention may be applied to a substrate processing apparatus that discharges the processing liquid from below the substrate toward the upper side or diagonally upward, or discharges the processing liquid along the inner bottom surface of the storage space as in Patent Document 1.

In addition, in the above embodiment, the present invention is applied to a substrate processing apparatus that performs chemical processing using a chemical solution containing phosphoric acid and a substrate processing apparatus that performs rinsing processing, but the scope of application of the present invention is not limited to this, and the present invention can be applied to substrate processing techniques in general in which a substrate is immersed in a processing solution other than the above chemical solution or rinsing solution and air bubbles are supplied to the substrate in the processing solution to perform substrate processing.

This invention can be applied to any substrate processing apparatus that immerses a substrate in a processing liquid, such as a chemical solution or pure water, stored in a processing tank and supplies air bubbles to the substrate in the processing liquid.

81...First chemical processing unit (substrate processing apparatus)
82: First rinse processing unit (substrate processing apparatus)
83: Second chemical processing unit (substrate processing apparatus)
84: Second rinse processing unit (substrate processing apparatus)
810, 810a, 810b... Lifter (substrate holder)
821: Processing tank 821f: Storage space 821g: Upper opening 830: Processing liquid discharge section 840: Air bubble supply section 841, 841a to 841d: Bubbler 842: Bubble piping 843, 846 to 848: Protruding section 845: Air bubble discharge port V: Air bubble W: Substrate

Claims (7)

a processing tank having a storage space for storing a processing liquid, the processing tank processing a substrate by immersing the substrate in the processing liquid stored in the storage space;
a substrate holder that holds the substrate in an upright position within the storage space;
a processing liquid discharge unit provided below the substrate held by the substrate holder and configured to discharge the processing liquid into the storage space to form a flow of the processing liquid within the storage space;
a pipe disposed below the substrate held by the substrate holding unit within the storage space, and a bubble supply unit that protrudes from the pipe in the direction of flow of the processing liquid , has a hollow protruding portion having a columnar shape , and supplies bubbles into the processing liquid stored in the storage space by discharging gas that has been sent to the protruding portion via the pipe from a bubble discharge port provided at the center of the tip of the protruding portion;
A substrate processing apparatus comprising: a processing tank having a storage space for storing a processing liquid, the processing tank processing a substrate by immersing the substrate in the processing liquid stored in the storage space;
a substrate holder that holds the substrate in an upright position within the storage space;
a processing liquid discharge unit provided below the substrate held by the substrate holder and configured to discharge the processing liquid into the storage space to form a flow of the processing liquid within the storage space;
a pipe disposed below the substrate held by the substrate holding unit within the storage space, and a hollow protruding portion protruding from the pipe in the flow direction of the processing liquid , the hollow protruding portion having a tapered shape with an outer diameter dimension decreasing toward the tip , the bubble supply portion discharging gas sent through the protruding portion via the pipe from a bubble discharge port provided at the tip of the protruding portion to supply bubbles into the processing liquid stored in the storage space;
A substrate processing apparatus comprising: 3. The substrate processing apparatus according to claim 1,
The protruding portion is made of a resin material. The substrate processing apparatus according to claim 3,
The substrate processing apparatus, wherein the protruding portion is made of at least one material selected from the group consisting of polyether ether ketone (PEEK), perfluoroalkoxyalkane (PFA), and polytetrafluoroethylene (PTFE). 5. The substrate processing apparatus according to claim 3,
The tip of the protruding portion is a substrate processing apparatus undergoing plasma processing. 6. The substrate processing apparatus according to claim 1,
the substrate holder holds the plurality of substrates while spaced apart from one another in a horizontal direction;
the bubble supply unit is provided on a side wall of the pipe extending in the horizontal direction, and the protruding portions are arranged in a horizontal direction;
the substrate and the protruding portions are alternately positioned in the horizontal direction,
The substrate processing apparatus, wherein each of the protruding portions supplies the bubbles from the bubble discharge port toward between the substrates adjacent to each other in the horizontal direction. 7. The substrate processing apparatus according to claim 1,
The processing tank is a substrate processing apparatus in which the processing liquid supplied from the processing liquid discharge unit overflows from an upper opening of the storage space while the substrate is being processed.

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