CN118402046A

CN118402046A - Substrate processing apparatus and substrate processing method

Info

Publication number: CN118402046A
Application number: CN202280082834.4A
Authority: CN
Inventors: 永松辰也; 稻田尊士; 滨岛悠太; 本田拓巳; 河野央; 菅野至
Original assignee: Tokyo Electron Ltd
Current assignee: Tokyo Electron Ltd
Priority date: 2021-12-21
Filing date: 2022-12-09
Publication date: 2024-07-26

Abstract

The substrate processing apparatus includes: a batch processing section having a plurality of batch processing units, each of which is configured to perform liquid processing on a plurality of substrates at a time in a processing liquid stored in a processing tank; a single-wafer processing unit that performs processing on the substrates processed by the batch processing unit one by one; a standby unit for waiting the substrate processed by the batch processing unit in the immersion liquid in the immersion tank; and a conveyance system that conveys the substrates from the standby section to the single-wafer processing section, the conveyance system including a first substrate conveyance unit for taking out the substrates one by one from the immersion liquid. The standby unit performs at least one of a first liquid treatment for hydrophilizing the surface of the substrate, or a second liquid treatment for increasing or maintaining the hydrophilicity of the surface, and the second liquid treatment for making the electromotive potential of the surface of the substrate negative.

Description

Substrate processing apparatus and substrate processing method

Technical Field

The present disclosure relates to a substrate processing apparatus and a substrate processing method.

Background

In the manufacture of semiconductor devices, a chemical solution is supplied to a substrate such as a semiconductor wafer, and the substrate is subjected to a liquid treatment such as a wet etching treatment or a cleaning treatment. Patent document 1 describes a substrate processing system that performs such liquid processing on a substrate. The substrate processing system includes a liquid medicine tank, a rinsing buffer tank, a transfer unit, and a spin dryer unit. The chemical solution tank is configured to perform batch-type chemical solution treatment on the plurality of substrates, the rinse tank is configured to perform batch-type water rinse treatment on the plurality of substrates after the chemical solution treatment, and the spin-drying section is configured to perform single-wafer spin-drying treatment on each of the plurality of substrates subjected to the water rinse treatment. The water washing buffer tank is used for temporarily storing the plurality of substrates after the water washing treatment in water. The transfer unit transfers the plurality of substrates stored in the water-washing buffer tank to the spin dryer unit one by one.

Prior art literature

Patent literature

Patent document 1: japanese patent No. 3192951

Disclosure of Invention

Problems to be solved by the invention

The present disclosure provides a technique capable of preventing deterioration of a surface state of a substrate when the substrate is transferred from a batch processing section to a single-wafer processing section.

A substrate processing apparatus according to an embodiment of the present disclosure includes: a batch processing section having a plurality of batch processing units, each of the batch processing units including a processing tank for storing a processing liquid, and performing liquid processing on a plurality of substrates at once by immersing the substrates in the processing liquid stored in the processing tank; a single-wafer processing unit that includes a single-wafer processing unit that performs processing on the plurality of substrates processed by the batch processing unit one by one; a standby unit having an immersion tank for storing an immersion liquid, the standby unit waiting the plurality of substrates processed by the batch processing unit while immersed in the immersion liquid; and a conveyance system that conveys the plurality of substrates from the standby unit to the single-wafer processing unit, wherein the conveyance system includes a first substrate conveyance unit that removes the plurality of substrates immersed in the immersion liquid in the immersion tank from the immersion liquid one by one, and the standby unit is configured to be capable of performing at least one of a first liquid treatment that hydrophilizes a surface of the substrate or a liquid treatment that increases or maintains hydrophilicity of the surface of the substrate, and a second liquid treatment that increases or maintains zeta potential, that is, electromotive potential, of the surface of the substrate.

According to one embodiment of the present disclosure described above, it is possible to prevent deterioration of the surface state of the substrate when the substrate is transferred from the batch processing section to the single-wafer processing section.

Drawings

Fig. 1 is a schematic cross-sectional view of a substrate processing system according to an embodiment of a substrate processing apparatus.

Fig. 2 is a schematic side view showing one configuration example of the standby unit and the device related to the standby unit.

Fig. 3 is a schematic plan view showing one configuration example of the standby unit and the device related to the standby unit.

Fig. 4 is a schematic front view for explaining the action of the third substrate transfer robot in taking out a substrate from the substrate holding section of the standby unit.

Fig. 5 is a schematic front view for explaining an operation of the substrate holder of the standby unit when receiving a substrate from the second substrate transfer robot.

Fig. 6 is a schematic vertical cross-sectional view showing one configuration example of the single-sheet type liquid processing unit.

Fig. 7 is a schematic vertical sectional view showing one configuration example of the supercritical drying unit.

Fig. 8 is a schematic vertical cross-sectional view showing one configuration example of the substrate transfer unit.

Fig. 9 is a schematic cross-sectional view showing a structure of an etching target in specific example 1 of a substrate processing method.

Fig. 10 is a schematic cross-sectional view showing the structure of an etching object in specific examples 2 and 3 of the substrate processing method.

Fig. 11 is a schematic vertical cross-sectional view showing an immersion tank as a first configuration example of a standby section of another embodiment of the substrate processing apparatus.

Fig. 12 is a schematic vertical cross-sectional view showing an immersion tank as a second configuration example of a standby section of another embodiment of the substrate processing apparatus.

Fig. 13 is a schematic vertical cross-sectional view showing an immersion tank as a third configuration example of a standby section of another embodiment of the substrate processing apparatus.

Fig. 14 is a schematic vertical cross-sectional view showing an immersion tank as a fourth configuration example of a standby section of another embodiment of the substrate processing apparatus.

Fig. 15 is a brabender graph (Pourbaix diagram) for illustrating the metal loss of tungsten.

Detailed Description

Next, a substrate processing system 1 according to an embodiment of the substrate processing apparatus of the present disclosure will be described with reference to the drawings. In order to simplify the explanation about the direction, an XYZ orthogonal coordinate system is set and is shown in the lower left part of fig. 1. The Z direction is the up-down direction, and the Z positive direction is the up direction.

As shown in fig. 1, a substrate processing system 1 according to one embodiment of the substrate processing apparatus of the present disclosure includes a container carry-in/out section 2, a first interface section 3, a batch processing section 4, a second interface section 5, and a single-wafer processing section 6.

The substrate processing system 1 includes a control device 100. The control device 100 is configured by a computer, and includes a calculation processing unit 101 and a storage unit 102. The memory unit 102 stores programs (including a process recipe) for controlling various processes performed in the substrate processing system 1. The arithmetic processing unit 101 reads and executes the program stored in the storage unit 102 to control the operations of the respective constituent elements of the substrate processing system 1 described later, thereby executing a series of processes described later. The control device 100 may be provided with a user interface such as a keyboard, a touch panel, or a display. The above-described program may be recorded in a computer-readable storage medium, and installed from the storage medium to the storage section 102 of the control device 100. Examples of the computer readable storage medium include a Hard Disk (HD), a Flexible Disk (FD), an optical disk (CD), a magneto-optical disk (MO), and a memory card.

The container loading and unloading unit 2 includes a stage 21 for placing a substrate transport container F (hereinafter, simply referred to as "container F" for simplicity) such as a FOUP, and a container holder 22 for storing the container F. A plurality of (four in the example of the figure) movable tables 211 are provided in the table portion 21 so as to be aligned in the Y direction. A partition wall 212 is provided between the table portion 21 and the container holder 22. An opening (not shown) with a shutter is provided in the partition wall 212 at a position corresponding to each movable stage 211. The container F placed on the movable table 211 can be moved into the container holder 22 through the opening in which the shutter is opened.

The container holder 22 is provided with a plurality of container holders 221 and a container transfer robot (container transfer mechanism) 222. The container transfer robot 222 can transfer the container F between the movable table 211 and an arbitrary container holding table 221 located in the container holder 22. One (or two) of the plurality of container holding stages 221 on the first interface 3 side is a substrate taking-out stage 221A, and the other container holding stage 221 is a substrate holding stage 221B.

A partition wall 223 is provided between the container holder 22 and the first interface section 3. An opening (not shown) with a shutter and an opening/closing mechanism (not shown) for a lid of the container F are provided at a position of the partition wall 223 corresponding to the substrate taking-out stage 221A.

A first substrate transfer robot (first transfer mechanism) 31 is provided in the first interface section 3. The first substrate transfer robot 31 has a plurality of (e.g., 5 to 25) substrate holders 32 as end effectors. The first substrate transfer robot 31 collectively takes out a plurality of (for example, 5 to 25) substrates W from the containers F placed on the substrate take-out stage 221A, and transfers the substrates W to the second substrate transfer robot 41 (second transfer mechanism) (indicated by a broken line) waiting in the transfer area 33. At this time, the first substrate transfer robot 31 takes out the substrate W stored in the container F in a horizontal posture, converts the substrate W into a vertical posture, and transfers the substrate W to the second substrate transfer robot 41.

Further, 50 substrates (the amount of two containers) can be processed at a time by the batch processing section 4. In this case, a pitch change mechanism for changing the interval between the substrate holders 32 may be provided to the end effector of the first substrate transfer robot 31, or a pitch change mechanism may be provided to the delivery area 33. The pitch changing mechanism is a mechanism that sets the arrangement interval (pitch) of the substrates W to 1/2 of the arrangement interval when the substrates W are accommodated in the container F, for example, and is well known in the art.

In the following description, a description will be given on the premise that one substrate group is constituted by 25 substrates W (25 substrates are simultaneously processed at a time by the batch processing section 4).

The batch processing section 4 is provided with a plurality of batch processing units 42. In fig. 1, four batch units 42 are depicted, but the number of batch units 42 is not limited to this, and a number of batch units 42 corresponding to the process to be performed on the substrate W is provided. The plurality of batch processing units 42 have substantially the same basic configuration as each other, and include a processing tank for storing a processing liquid, a substrate holder (called a wafer boat or the like) for holding a substrate in the processing tank, and a lifting mechanism for lifting and lowering the substrate holder. The substrate holders can hold, for example, 25 substrates W in a vertical posture at equal intervals in the horizontal direction. The plurality of batch units 42 are arranged in the X direction.

The plurality of batch units 42 may include a general-purpose batch unit capable of coping with various processes, and a batch unit dedicated to a specific process. As the latter, a batch processing unit for phosphoric acid (H ₃PO₄) treatment is exemplified. In the phosphoric acid treatment, the treatment liquid in the treatment tank is usually brought to a substantially boiling state at a high temperature, and bubbling may be performed. In order to cope with such a process, for example, a lid for closing an upper opening of a processing tank, a means for monitoring and maintaining a boiling state of a processing liquid, a bubbling nozzle, a means for pressing a substrate against a substrate holder, and the like are additionally provided in a batch processing unit for phosphoric acid processing.

The plurality of batch processing units 42 include, for example, a first chemical processing unit, a first rinse processing unit, a second chemical processing unit, and a second rinse processing unit. The substrate W is sequentially placed in the first chemical solution processing unit, the first rinse processing unit, the second chemical solution processing unit, and the second rinse processing unit, and a process (chemical solution process or DIW rinse process) corresponding to the liquid stored in the processing tank is performed in each batch processing unit 42. Specific examples of the processing performed by the batch processing unit 42 will be described later.

A cleaning unit 43 for cleaning the substrate holding portion 413 of the second substrate transfer robot 41 and drying the substrate as necessary is provided at a position closest to the first interface portion 3 of the batch processing portion 4.

A standby unit (standby unit) 44 is provided at a position of the batch processing section 4 farthest from the first interface section 3. The standby unit 44 includes an immersion tank 441 for storing an immersion liquid for immersing the substrate W, a substrate holder 442 (referred to as a wafer boat or the like) for holding the substrate in the immersion tank 441, and a moving mechanism 443 (see fig. 2 and 3) for moving the substrate holder 442 in the horizontal direction while lifting and lowering the substrate holder. The substrate holders 442 can hold, for example, 25 substrates W in a vertical posture at equal intervals in the horizontal direction. In the standby unit 44, a process of changing the surface state change of the substrate W is performed in preparation for the subsequent single-sheet conveyance. Specifically, the treatment is, for example, a hydrophilization treatment for preventing interruption of liquid on the surface of the substrate W or a treatment for making the zeta potential of the surface of the substrate W negative in order to prevent adhesion of particles to the surface of the substrate W. The detailed configuration of the standby unit 44 will be described later.

The processing liquid stored in the batch processing unit 42 of the substrate W immediately before being placed in the standby unit 44 cannot be a processing liquid that hinders the processing performed by the standby unit 44, and is usually a rinse liquid, specifically, for example, DIW.

The batch processing section 4 is provided with the second substrate transfer robot 41. The second substrate transfer robot 41 includes a guide rail 411 extending in the direction (X direction) in which the plurality of batch processing units 42 are arranged, a traveling body 412 capable of traveling along the guide rail 411, and a substrate holding portion 413 attached to the traveling body 412.

The substrate holding portion 413 has, for example, three substrate holding bars 414 extending in the Y direction. Each substrate holding bar 414 has substrate holding grooves (not shown) arranged at equal intervals along the Y direction. By fitting the peripheral edge portions of the substrates W into the substrate holding grooves, 25 substrates W are held at equal intervals in the Y direction in a vertical posture by the substrate holding portions 413.

One end of the guide rail 411 extends to the front of the interface region 33 within the first interface portion 3. Therefore, as described above, the substrates can be transferred between the first substrate transfer robot 31 and the second substrate transfer robot 41 at the transfer area 33. The other end of the guide rail 411 extends to the front face of the standby unit 44. Therefore, the second substrate transfer robot 41 can transfer substrates to and from the standby unit 44 and the optional batch processing unit 42. The substrate holding portion 413 of the second substrate transfer robot 41 can also access the cleaning unit 43 to clean the substrate holding portion 413.

A third substrate transfer robot 51 and one or more (for example, two) substrate transfer units 52 are provided in the second interface section 5. When a plurality of substrate transfer units 52 are provided, these substrate transfer units 52 are provided in a stacked manner, for example, in the up-down direction.

The third substrate transfer robot 51 can take out the substrates W held by the substrate holders 442 in the immersion tank 441 of the standby unit 44 one by one, and place the substrates W on the substrate transfer unit 52 after changing the vertical posture to the horizontal posture.

The single-wafer processing section 6 is provided with one or more single-wafer liquid processing units (single-wafer processing units) 61, one or more supercritical drying units 62 for performing supercritical drying of the substrates W processed by the single-wafer liquid processing units 61, and a fourth substrate transfer robot 63. In the case where a plurality of single-sheet liquid processing units 61 and a plurality of supercritical drying units 62 are provided, these units can be provided in a stacked manner in the up-down direction, for example. The single-wafer liquid processing unit 61 and the supercritical drying unit 62 are single-wafer processing units that process one substrate W at a time.

The fourth substrate transfer robot 63 includes, for example, an end effector movable by a multi-axis drive mechanism 631 movable in the X direction and the Y direction, movable in the Z direction, and rotatable about a vertical axis. The end effector is a substrate holder 632, for example, in the shape of a fork, capable of holding a single substrate. The fourth substrate transfer robot 63 can carry in and out substrates among the substrate transfer unit 52, the single-wafer liquid processing unit 61, the supercritical drying unit 62, and the substrate transfer unit 35 in the first interface section 3 in the second interface section 5. The substrate W is always maintained in a horizontal posture while being transferred by the fourth substrate transfer robot 63.

As the single-wafer liquid processing unit 61, any single-wafer liquid processing unit known in the technical field of semiconductor manufacturing apparatuses can be used. Next, a configuration example of a single-chip liquid processing unit 61 that can be used in the present embodiment will be briefly described with reference to fig. 6. The single-wafer liquid processing unit 61 includes a rotation holding plate (holding plate) 611 capable of holding the substrate W in a horizontal posture and rotating the substrate W about a vertical axis, and one or more nozzles 612 for ejecting a processing liquid to the substrate W held and rotated by the rotation holding plate 611. The nozzle 612 is carried by an arm 613 for moving the nozzle 612. The single-wafer liquid processing unit 61 includes a liquid receiving cup 614 for collecting the processing liquid scattered from the rotating substrate W. The liquid receiving cup 614 has a liquid outlet 615 for discharging the recovered processing liquid to the outside of the single-piece liquid processing unit 61, and an air outlet 616 for discharging the atmosphere in the liquid receiving cup 614. Clean gas (clean air) is blown downward from a blower filter unit 618 provided at the top of the chamber 617 of the unit 61, is sucked into the liquid receiving cup 614, and is discharged to the exhaust port 616.

In the present embodiment, the fourth substrate transfer robot 63 takes out the substrate W from the substrate transfer unit 52 in the second interface section 5 and carries it into the single-wafer liquid processing unit 61. In the single-wafer liquid processing unit 61, DIW rinsing processing, IPA substitution processing, and IPA sump forming processing are sequentially performed. In the DIW rinsing process, DIW is supplied from the nozzle 612 to the surface of the rotating substrate W, and the liquid adhering to the surface of the substrate W is rinsed off by the DIW. In the IPA substitution process, the supply of IPA from the nozzle 612 to the surface of the rotating substrate W is continued to substitute DIW on the surface of the substrate W with IPA. In the IPA puddle formation process, the rotation speed of the substrate is greatly reduced while the supply of IPA from the nozzle 612 is continued, so that a relatively thick IPA liquid film is formed on the surface of the substrate W, and then the rotation of the substrate is stopped.

As the supercritical drying unit 62, any supercritical drying unit known in the technical field of semiconductor manufacturing apparatuses can be used. Next, a structural example and an operation of the supercritical drying unit 62 usable in the present embodiment will be briefly described with reference to fig. 7. The supercritical drying unit 62 includes a supercritical chamber 621 and a substrate support tray 622 that can be advanced and retracted relative to the supercritical chamber 621. Fig. 1 depicts a substrate support tray 622 withdrawn from the supercritical chamber 621, and in this state, the fourth substrate transfer robot 63 transfers the substrate W to and from the substrate support tray 622.

The substrate W with the IPA puddle formed therein is taken out from the single-wafer liquid processing unit 61 by the fourth substrate transfer robot 63 and placed on the substrate support tray 622 of the supercritical drying unit 62. Next, the substrate support tray 622 is housed in the supercritical chamber 621, and the supercritical chamber 621 is sealed by a lid 625 integrated with the substrate support tray 622. In this state, a supercritical fluid (for example, supercritical carbon dioxide (CO ₂)) is supplied from a supercritical fluid supply source (not shown) into the supercritical chamber 621 via the supply port 623, and the supercritical fluid flows along an arrow in the figure and is discharged from the discharge port 624. Further, CO ₂ may be supplied through another supply port (not shown) opened to the lower surface of the substrate support tray 622 until the pressure in the supercritical chamber 621 increases. IPA on the substrate W is replaced by supercritical CO ₂ flowing in the vicinity thereof. After the IPA is replaced with supercritical CO ₂, the inside of the supercritical chamber 621 is returned to normal pressure. Thereby, the supercritical CO ₂ is vaporized, and the surface of the substrate W is dried. In this way, the collapse of the pattern formed on the surface of the substrate W can be prevented, and the substrate W can be dried.

The dried substrate is taken out of the supercritical drying unit 62 by the fourth substrate transfer robot 63 and is transferred to the substrate transfer unit 35 provided in the first interface 3. The first substrate transfer robot 31 of the first interface 3 takes out the substrate W from the substrate transfer unit 35, and accommodates the processed substrate W in the container F placed on the substrate holding stage 221B.

The container F containing the processed substrates W is placed on the movable table 211 by the container transfer robot 222 of the container stocker 22, and is carried out to the table section 21.

Next, one configuration example and an operation of the batch processing section 4 (particularly, the standby unit 44 thereof) and the second interface section 5 will be described in detail with reference to fig. 2 to 5 and fig. 8.

In fig. 2 and 3, the second substrate transfer robot 41 and the third substrate transfer robot 51 are depicted together with the standby unit 44.

As described above, the standby unit 44 has the dipping tank 441. The immersing tank 441 includes an inner tank 441A for storing an immersing liquid, and an outer tank 441B for receiving the immersing liquid overflowed from the inner tank 441A. The immersion liquid flowing out of the outer tank 441B flows into the circulation line 444 and is discharged toward the substrate W from the nozzle 445 provided in the inner tank 441A. The nozzle 445 may be a rod-type nozzle having ejection ports arranged at equal intervals along the arrangement direction of the substrates W in the inner groove 441A. The circulation line 444 is provided with a pump for forming a circulation flow, a filter for removing particulates, and a temperature regulator such as a heater for adjusting the temperature of the immersion liquid.

As described above, the standby unit 44 has the substrate holder 442 that holds the substrate in the immersion tank 441. The substrate holder 442 has a flat plate-like base portion 442A extending in the vertical direction (Z direction), and two sets of support members 442B extending in the horizontal direction (Y direction) from the base portion 442A. Each group of support members 442B has two support rods 442C having their base ends fixed to the base portion 442A, and a fixing member 442D for fixing between the front ends of the two support rods 442C. Each support bar 442C is formed with substrate holding grooves (not shown) at equal intervals in the Y direction, which receive the peripheral edge portion of the substrate W and position the substrate W in the Y direction. The substrate holders 442 can hold a plurality of, for example, 25 substrates W in a vertical posture at equal intervals in the Y direction.

The standby unit 44 has a moving mechanism 446 capable of moving the substrate holder 442 in the Y direction and the Z direction. The moving mechanism 446 can move the substrate holder 442 between a delivery position (indicated by a two-dot chain line in fig. 2) where the substrate can be delivered to and from the second substrate transfer robot 41 and an immersion position (indicated by a solid line in fig. 3) where the held substrate W is immersed in the immersion liquid stored in the immersion tank 441.

As shown in fig. 5, the two sets of support members 442B of the substrate holders 442 of the standby unit 44 can pass through gaps between the three substrate holding bars 414 constituting the substrate holding portion 413 of the second substrate transfer robot 41. Therefore, by relatively moving the substrate holders 442 (support members 442B) and the substrate holding portions 413 (substrate holding bars 414) in the Z direction, a plurality of substrates W can be collectively transferred between the support members 442B and the substrate holding bars 414.

The arrow in fig. 5 indicates the relative movement between the support member 442B and the holding rod 413A in the up-down direction. In fig. 5, when the substrate holding bar 414 indicated by a filled solid circle is located more upward than the support member 442B, the substrate W held by the support member 442B becomes held by the substrate holding bar 414. By performing the relative movement opposite to the above, the substrate W held by the substrate holding bar 414 becomes held by the support member 442B.

As is clear from the above description, the configuration of the standby unit 44 is the same as that of a batch liquid processing apparatus known in the art. That is, the configuration of the batch processing unit 42 in the present embodiment may be the same as that of the standby unit 44, and the transfer of the substrate W between the batch processing unit 42 and the second substrate transfer robot 41 may be performed in the same manner. Therefore, a description about the structure of the batch processing unit 42 is omitted. In addition, the main difference between the batch processing unit 42 and the standby unit 44 is that: not only the second substrate transfer robot 41 but also the third substrate transfer robot 51 can access the standby unit 44 and the liquid stored in the tank.

The third substrate transfer robot 51 is configured as a single-piece transfer robot. The end effector of the third substrate transfer robot 51 is configured as a single substrate holder 511 in the form of a thin plate. In one embodiment as illustrated, the substrate holder 511 has a base portion 511A, and a pair of elongated front end portions 511B connected to the base portion 511A. Each front end portion 511B has a size that can be inserted between two support bars 442C of each support member 442B constituting the substrate holder 442 (see fig. 4).

As shown in fig. 2 and 4, the substrate holder 511 has a plurality (three in the example of the drawing) of holding claws 512A, 512B (schematically indicated by circles filled with dots in fig. 4). In the illustrated example, a movable grip claw 512A is provided at the tip of the base portion 511A of the substrate holder 511, and a fixed grip claw 512B is provided at the tip of each tip portion 511B. The holding claws 512A and 512B have a shape capable of engaging with the peripheral edge portion (the area near APEX) of the substrate W.

As shown in fig. 2 and 3, in a state where the substrate holder 511 is brought close to the substrate W in the Y direction and the movable grip claw 512A is separated from the fixed grip claw 512B, the movable grip claw 512A and the fixed grip claw 512B are positioned slightly apart from the peripheral edge of the substrate W. In this state, the movable grip claw 512A is moved so as to approach the fixed grip claw 512B, whereby the substrate W can be gripped by the movable grip claw 512A and the fixed grip claw 512B. Next, by moving the substrate holder 511 directly above (in the positive Z direction), the substrate W can be taken out while the peripheral edge portion of the substrate W is pulled out from the substrate holding groove, not shown, of the support rod 442C of the substrate holder 442.

The third substrate transfer robot 51 may be configured to satisfy the following functions (1) and (2), and may be configured as a multi-axis robot (for example, a multi-axis robot having an X axis, a Y axis, a Z axis, and a θ axis), or may be configured as an articulated robot.

(1) The substrate W can be taken out from the inner groove 441A by moving the substrate W in the vertical direction (Z-positive direction) in a state where any of the substrates W held by the substrate holders 442 in the inner groove 441A is sandwiched by the substrate holders 511.

(2) The substrate W in the vertical posture in the inner groove 441A can be placed in the substrate transfer unit 52 while being converted into the horizontal posture.

Fig. 1 to 3 schematically show a third substrate transfer robot 51 configured as an articulated robot.

As shown in fig. 2 and 3, an injection nozzle 447 may be attached to the immersion tank 441. The injection nozzle 447 can be moved in the Y direction by a Y direction moving mechanism 448 (only shown in fig. 3) slightly above the liquid surface of the immersion liquid stored in the inner tank 441A. The spray nozzle 447 can blow the spray liquid to the surface of the substrate W in the middle of or immediately after the third substrate transfer robot 51 lifts up from the immersion liquid. The spray nozzle 447 is preferably configured to uniformly blow the spray liquid onto the surface of the substrate W. The injection nozzle 447 can be configured as a rod-type nozzle having injection ports arranged at equal intervals in the X direction, for example. In this case, the nozzle 447 is positioned by the Y-direction moving mechanism 448 at a position close to and opposite the surface of the substrate W lifted by the third substrate transfer robot 51, and blows the ejection liquid onto the surface of the substrate W.

The third substrate transfer robot 51 converts the substrate W taken out of the immersion tank 441 into a horizontal posture and then carries the substrate W into the substrate transfer unit 52. The substrate transfer unit 52 is a unit that relays transfer of the substrate W between the third substrate transfer robot 51 and the fourth substrate transfer robot 63. Fig. 8 schematically shows an example of the structure of the substrate transfer unit 52. The third substrate transfer robot 51, the substrate transfer unit 52, and the fourth substrate transfer robot 63 constitute a transfer system for transferring the substrates W from the batch processing section 4 (standby unit 44) to the single-wafer processing section 6.

The substrate transfer unit 52 has a plurality of (e.g., three) support pins 521 as substrate support members. The third substrate transfer robot 51 transfers the substrate W from the transfer port 522 into the substrate transfer unit 52, and horizontally places the substrate W on the support pins 521. A cover liquid nozzle 523 for ejecting a cover liquid onto the surface of the substrate W is provided on the top of the substrate transfer unit 52. The coating liquid nozzle 523 supplies the coating liquid so as to form a puddle (liquid film) of the coating liquid on the entire surface of the substrate W. The coating liquid is DIW, for example, but not limited thereto, and may be a treatment liquid for zeta potential negative treatment described later.

A liquid film thickness sensor (not shown) or a camera (not shown) is provided on the top of the substrate transfer unit 52, and the coating liquid can be supplied from the coating liquid nozzle 523 to the surface of the substrate W only when the liquid film on the surface of the substrate W is to be interrupted due to drying or the like. Alternatively, the coating liquid may be supplied from the coating liquid nozzle 523 to the surface of the substrate W only when the substrate W remains in the substrate transfer unit 52 for a time period at which the surface of the substrate W is at risk of drying (that is, at least a part of the surface is exposed to the atmosphere). In this case, the retention time of the substrate W in the substrate transfer unit 52 may be counted by a timer. In the above case, the control device 100 causes the coating liquid nozzle 523 to discharge the coating liquid onto the substrate W based on the detection result of the sensor or the camera or based on the measurement result of the timer.

After the substrate W placed in the substrate transfer unit 52 is expected to be carried into the single-wafer liquid processing unit 61, the substrate W is taken out through the carrying-out port 524 by the fourth substrate carrying robot 63 and carried into the single-wafer liquid processing unit 61. Thereafter, the path through which the substrate W passes is as previously described.

Next, the liquid (impregnating liquid, spraying liquid) supplied to the substrate W in the standby unit 44 and the liquid (covering liquid) supplied to the substrate W in the substrate delivery unit 52 will be described. The following problems may be given as problems that may occur during the conveyance from the batch processing section 4 to the single-chip processing section 6.

After the final chemical treatment is performed on the substrate W in the batch processing section 4, if the surface of the substrate becomes hydrophobic, liquid interruption may occur during the conveyance from the batch processing section 4 to the single-wafer processing section 6, and a part of the surface of the substrate may be exposed. The exposure of the substrate surface may cause collapse of the pattern on the substrate surface, or defects such as particles and water marks on the substrate surface (problem 1).

After the final chemical treatment is performed on the substrate W in the batch processing section 4, if the surface of the substrate is charged, the probability that particles floating in the liquid adhere to the substrate increases (because the zeta potential of the particles is opposite to that of the surface of the substrate) (problem 2).

In the present embodiment, the standby unit 44 performs liquid processing for eliminating at least one of the problems 1 and 2.

The liquid treatment for eliminating the above-mentioned problem 1 is a treatment for hydrophilizing the surface of the substrate (hereinafter, simply referred to as "hydrophilization treatment"). Since the hydrophilization treatment takes a relatively long time, the substrate is immersed in the immersion liquid (treatment liquid for hydrophilization treatment) stored in the immersion tank 441 of the standby unit 44. As the treatment liquid for hydrophilization treatment, any of the following can be used, for example.

-SC2

Ozone water

Hydrogen peroxide water (H ₂O₂)

SPM (Hydrogen peroxide sulfate aqueous solution)

The type of the processing liquid used in the final chemical liquid processing (excluding the DIW rinsing process as the final step) performed by the batch processing section 4, the surface state of the processed substrate W (the material of the exposed surface, the chemical state (whether or not the terminal has a hydrophilic group, etc.), and the like can be considered to determine which of these processing liquids is used. Please refer to a specific example of the processing described later.

In the present embodiment, at least 25 substrates are immersed in the treatment liquid for hydrophilization treatment in the immersion tank 441 at the same time, and then taken out one by one. That is, the dipping time of the first and last taken out substrates is completely different. Therefore, the treatment liquid for hydrophilization treatment cannot be a treatment liquid for etching the surface of the substrate at a level that would be a problem. The temperature of the treatment liquid for hydrophilization treatment is preferably, but not limited to, normal temperature from the viewpoint of etching inhibition.

The liquid treatment for eliminating the above-described problem 2 is a treatment for allowing a liquid (liquid film) having a negative zeta potential on the surface of the substrate to adhere to the surface of the substrate W (hereinafter, referred to as "zeta potential negative treatment" for simplicity). Since zeta potential negative treatment can be performed in a shorter time than hydrophilization treatment, it can be performed by immersing in the immersion liquid (the treatment liquid for zeta potential negative treatment) in the immersion tank 441, or by blowing the ejection liquid (the treatment liquid for zeta potential negative treatment) from the ejection nozzle 447 onto the surface of the substrate.

As the treatment liquid for zeta potential negative treatment, any of the following can be used, for example.

Functional water (for example DIW with trace amounts of ammonia)

TMAH (tetramethyl ammonium hydroxide)

-Organic alkaline solution

-Anionic surfactants

From the viewpoint of suppressing etching, the temperature of the treatment liquid for zeta potential negative treatment is preferably (but not limited to) normal temperature.

In addition, for example, in the case where the last chemical solution process performed by the batch processing section 4 is SC1 process (after which DIW rinse process is performed), the surface of the substrate W may be sufficiently hydrophilized at the time point when the substrate W is put into the standby unit 44. In this case, only zeta potential negative processing can be performed by the standby unit 44. In this case, zeta potential negative treatment can also be performed using the injection nozzle 447. In this case, too, since the substrate W is not brought into contact with the atmosphere during waiting, it is considered to wait the substrate in the immersion liquid by setting the immersion liquid in the immersion tank 441 to a suitable non-reactive liquid such as DIW. Needless to say, the zeta potential negative treatment may be performed using the immersion liquid (the treatment liquid for zeta potential negative treatment) in the immersion tank 441.

However, even when the surface of the substrate W is hydrophilic at the time point when the substrate W is placed in the standby unit 44, the treatment liquid for hydrophilization treatment may be stored in the immersing tank 441 to further increase the hydrophilicity or at least maintain the hydrophilicity.

As described above, by hydrophilizing the surface of the substrate W and making the zeta potential of the surface of the substrate W negative when the substrate W is separated from the standby unit 44, the following advantageous effects can be obtained.

By hydrophilizing the surface of the substrate W when the substrate W is separated from the standby unit 44, it is possible to prevent interruption of the liquid on the surface of the substrate W (disappearance of a part of the liquid film on the entire substrate surface) when the substrate W is lifted from the immersion liquid in the immersion tank 441. In addition, it is possible to prevent liquid interruption on the surface of the substrate W during the process of transferring the substrate W from the batch processing section 4 to the single-wafer processing section 6. Therefore, defects such as particles and water marks are prevented from being generated on the surface of the substrate W or collapse of the pattern is prevented from being generated due to exposure of the surface of the substrate W to the atmosphere.

In contrast, according to the above embodiment, even if the conveyance distance from the batch processing section 4 to the single-chip processing section 6 or the time required for conveyance becomes long, problems are less likely to occur. This means that an optimal layout can be adopted for each of the batch processing section 4 and the single-chip processing section 6. That is, there is no need to adopt an unreasonable layout in order to shorten the conveying distance or the time required for conveyance. In addition, in many cases, it is difficult to fully match the processing schedule of batch processing and single-wafer processing, and it is necessary to set a certain standby time for carrying-in of the substrates W to the single-wafer processing unit. According to the above embodiment, since the interruption of the liquid on the surface of the substrate W is difficult to occur, a problem is difficult to occur even if some standby time is set. Thus, flexibility in setting the conveyance schedule and the processing schedule is improved. In addition, in the case where the transfer unit 52 with the covering liquid nozzle 523 is provided between the batch processing section 4 and the single-wafer processing section 6, the possibility of liquid interruption at the surface of the substrate W during the conveyance of the substrate W from the batch processing section 4 to the single-wafer processing section 6 can be further reduced.

Further, by making the zeta potential of the surface of the substrate W negative when the substrate W is separated from the standby unit 44, it is possible to prevent or greatly suppress particles contained in the liquid film on the surface of the substrate W from adhering to the surface of the substrate W during the period in which the substrate W is transferred from the batch processing section 4 to the single-wafer processing section 6. Accordingly, there is no need to use an unreasonable layout for shortening the conveyance distance or the time required for conveyance, and flexibility in setting the conveyance arrangement and the processing arrangement is improved (because adhesion of particles due to zeta potential also tends to increase with time).

As described above, according to the present embodiment, it is possible to prevent the surface state of the substrate W from deteriorating when the substrate W is transferred from the batch processing section 4 to the single-wafer processing section 6.

Next, a specific example of a combination of the processing performed by each processing means of the batch processing section 4 and the hydrophilization processing and/or zeta potential negation processing performed by the standby means 44 will be described.

< Specific example 1>

In specific example 1, as shown in fig. 9, a SiN film of a substrate W having a laminated structure of SiO ₂/SiN of 3D-NAND was selectively etched in the batch processing section 4 (the left side of fig. 9 is before etching, and the right side is after etching). In this case, first, a selective etching process of the SiN film is performed by high-temperature phosphoric acid in the first batch processing unit 42, and then, a DIW rinsing process is performed in the second batch processing unit 42. Next, the third batch processing unit 42 performs the etching residue removal process using SC1, and finally, the fourth batch processing unit 42 performs the DIW rinsing process. Thereafter, the substrates are carried to the standby unit 44 and immersed in the standby liquid, and the substrates are taken out one by the third substrate carrying robot 51 and carried to the single-sheet processing section 6, where the drying process is performed in accordance with the procedure described herein.

In this specific example 1, most of the surface of the substrate after the treatment (including the surface inside the recess) is hydrophilic SiO ₂, and the hydrophilization treatment in the standby unit 44 is not required because the hydrophilization treatment is further improved by the treatment with SC1 in the third batch unit 42. Therefore, the standby unit 44 may perform only zeta potential negative processing. For example, a treatment liquid for zeta potential negative treatment (e.g., weakly alkaline functional water) may be stored in the immersing tank 441, and the substrate may be immersed therein. In this case, the injection nozzle 447 may not be used. The substrate transfer unit 52 may supply the processing liquid for zeta potential negative processing to the substrate W.

< Specific example 2>

In specific example 2, as shown in fig. 10, a part of the SiN film of the substrate W having the stacked structure of Si/SiO ₂/SiN constituting the cell transistor module of the 3D-DRAM was selectively etched in the batch processing section 4 (the left side in fig. 10 is before etching, the right side is after etching). In this case, first, a selective etching process of the SiN film is performed by high-temperature phosphoric acid in the first batch processing unit 42, and then, a DIW rinsing process is performed in the second batch processing unit 42. Thereafter, the substrates are carried to the standby unit 44 and immersed in the standby liquid, and the substrates are taken out one by the third substrate carrying robot 51 and carried to the single-sheet processing section 6, where the drying process is performed in accordance with the procedure described. After the second batch processing unit 42 is performed, the third batch processing unit 42 may perform the etching residue removal processing by SC1, and the fourth batch processing unit 42 may perform the DIW rinsing processing.

In this specific example 2, hydrophobic Si, hydrophilic SiO ₂, and semi-hydrophobic SiN were mixed on the surface of the substrate after the treatment (including the surface inside the recess), but the entire surface of the substrate was actually rendered hydrophobic to semi-hydrophobic by the hydrophobic Si. Therefore, the liquid is likely to be interrupted. Therefore, the hydrophilization treatment is performed in the standby unit 44. Specifically, for example, a treatment liquid (for example, ozone water) for hydrophilization treatment may be stored in the immersing tank 441, and the substrate W may be immersed therein.

< Concrete example 3>

Specific example 3 is a modification of specific example 2, and the structure of the substrate to be processed is the same as that of specific example 2. That is, siN is also exposed on the surface of the substrate W (including the surface of the recess). The SiN surface is DIW (pH 6 to 7), and the surface potential is close to neutral, so that particles are easily adsorbed. Therefore, the zeta potential negative processing is performed by the standby unit 44 so that the electric potential of the SiN surface and the electric potential of the microparticles are the same sign and repel each other. The zeta potential negative treatment can be performed by spraying the treatment liquid for the zeta potential negative treatment onto the substrate W by the spray nozzle 447. Both the hydrophilization treatment and the zeta potential negative treatment can be performed by the standby unit 44. In this case, it is preferable to perform hydrophilization treatment in the dipping tank 441 and zeta potential negative treatment by the jet nozzle 447. The zeta potential negative treatment can be performed in the dipping tank 441 without performing the hydrophilization treatment by the standby unit 44.

Next, another embodiment of the liquid treatment that can be performed by the standby unit 44 will be described. This other embodiment is to solve a problem that may occur due to the substrate W staying in the dipping tank 441 for a long time.

After being placed in the dipping tank 441 of the standby unit 44, a plurality of (e.g., 25 or 50) substrates W are carried to the single-wafer processing unit 6, and thus the substrates W are taken out one by one from the dipping tank 441. The residence time of the first substrate W taken out of the dipping tank 441 and the last substrate W taken out of the dipping tank 441 is completely different (for example, there is a difference of several hours). Confirmed by the following two experiments: in the case where the immersion liquid is DIW, there is a possibility that the surface of the substrate W (for example, bare silicon constituting the substrate W or a metal layer exposed to the surface of the substrate W, for example, tungsten wiring) is oxidized or dissolved by dissolved oxygen in the DIW.

[ Experiment 1]

The following tests were performed on bare silicon substrates: the natural oxide film was removed by DHF chemical cleaning, followed by DIW rinsing, and then the bare silicon substrate was immersed in DIW (dissolved oxygen concentration (DO) of about 5000 ppb) in an immersion tank having substantially the same structure as the immersion tank 441 shown in fig. 11. The film thickness of the natural oxide film on the surface of the bare silicon substrate was about without DIW immersion (immediately after the DIW rinse was completed)About 3hr for DIW immersionAbout 5hr for DIW immersionLeft and right. It is known that the natural oxide film gradually grows when bare silicon is immersed in DIW for a long period of time. As described in configuration example 1 described later, low DO DIW is continuously supplied into the immersion tank 441 at a small flow rate (for example, about 1 to 2L/min) to obtain DIW with DO of about 5000 ppb.

The bare silicon substrate is subjected to DHF chemical cleaning to remove a natural oxide film, followed by DIW rinsing, and finally drying, and the bare silicon substrate is stored in a FOUP (substrate transfer container) and placed in the FOUP. The film thickness of the natural oxide film on the surface of the bare silicon substrate is about after the bare silicon substrate is accommodated in the FOUPAbout after 6.2hr from being accommodated in the FOUP

As is clear from the above description, the natural oxide film growth is promoted by immersing in DIW (DO is about 5000 ppb) as compared with the case of storing in FOUP.

[ Experiment 2]

The following tests were performed: the substrate having the tungsten film formed on the surface was immersed in DIW (DO: about 5000 ppb) using the same immersion tank as in experiment 1. The film thickness of the tungsten film was reduced to about 1.5 to about 3hr for the DIW immersion timeAbout 2.5% in the case of a DIW impregnation time of 5hrLeft and right. It was found that dissolution of tungsten film was not negligible when immersed in DIW for a long period of time.

The inventors believe that dissolution of the tungsten film occurs by the following reaction.

< Oxidation >

As oxidation proceeds further, WO ₂ becomes WO ₃

< Dissolution >

Typically, the DIW provided as floor manager facilities has a dissolved oxygen concentration (DO) of about 5 ppb. When such low DO DIW is left in a state stored in the immersion tank 441, oxygen contained in the air around the immersion tank 441 is dissolved in the DIW, and DO may increase to more than 10000ppb. Further, when DIW was circulated so as to overflow from the dipping tank 441 and return again to the dipping tank 441, it was confirmed that dissolution of oxygen in DIW was promoted. DIW having relatively large amounts of oxygen dissolved in this manner may cause oxidation or dissolution (metal loss) by the above mechanism. Next, the configuration of the standby unit 44 capable of solving this problem will be described with reference to fig. 11 to 14.

Structural example 1

A configuration example 1 of the standby unit 44 and the dipping tank 441 will be described with reference to fig. 11. With respect to the configuration of the standby unit 44 and the dipping tank 441, fig. 2 is also referred to. The same components as those shown in fig. 2 are denoted by the same reference numerals.

A liquid supply nozzle 74 for supplying DIW is provided in the inner tank 411A of the immersing tank 441. DIW is supplied to a liquid supply nozzle 74 via a liquid supply line 72 connected at an upstream end to a DIW supply source 71 as floor manager facilities. The liquid supply line 72 is provided with a liquid flow adjusting portion 73. The flow adjuster 73 may be constituted by a single on-off valve, or may be constituted by a combination of an on-off valve, a flow rate control valve, a flow meter, and the like.

In general, low DO (e.g., less than 5 ppb) DIW is supplied from a DIW supply source as floor manager facilities provided in a semiconductor device manufacturing factory. Therefore, it is not necessary to provide a dedicated low DO-DIW supply device for realizing configuration example 1. However, a low DO-DIW supply device dedicated to the substrate processing system 1 may be provided as the case may be.

A DO sensor 75 for detecting the DO value of DIW stored in the inner tank 411A is provided in the inner tank 411A of the immersing tank 441.

A drain line 76 is connected to the bottom of the outer tank 411B of the dipping tank 441. The drain line 76 is connected to the plant waste system. The plurality of drain lines 76 may be provided at different positions of the outer tub 411B.

The operation of structural example 1 will be described. A plurality of, for example, 25 substrates W subjected to the final batch process (for example, a rinse process after chemical treatment) are carried in from the batch processing unit 42 subjected to the final process on the substrates W to the standby unit 44 by the second substrate carrying robot 41, and are collectively placed in the immersion tank 441 (inner tank 441A). Thereafter, the substrates W are carried out from the inner tank 441A one by the third substrate carrying robot 51. When the tank 441A is left in a state where DIW is retained therein, oxygen in the air around the tank 441A dissolves in the DIW, and the DO value of the DIW increases with the passage of time.

In order to prevent the DO value from exceeding the predetermined threshold value and to suppress the consumption amount of DIW, feedback control is performed under the control of the control device 100 (see fig. 1), for example. Here, the threshold value of the DO value is, for example, 100ppb, which does not cause oxidation, which is problematic, of the substrates W that are finally taken out of the inner tank 441A among the substrates W that are collectively placed in the immersion tank 441 (the inner tank 441A). For example, the threshold value may be set smaller (larger) as the longest residence time in the inner bath 441A of the substrate W is longer (shorter).

Feedback control can be performed by controlling the supply of low DO DIW from the DIW supply source 71 to the immersion tank 441 (inner tank 441A) via the liquid supply nozzle 74 based on a deviation between the DO value (measured value) detected by the DO sensor 75 and the target DO value, for example, 100ppb here. In the normal operation, since the inner tank 441A is filled with DIW, the same amount of DIW as the low DO DIW supplied from the liquid supply nozzle 74 overflows from the inner tank 441A to the outer tank 441B. Thus, a portion of the DIW in which DO is higher is replaced with DIW in which DO is lower (e.g., less than 5 ppb). As a result, DO of DIW in the inner tank 441A can be lowered. The higher the supply flow rate of DIW with low DO, the faster DO of DIW in the inner tank 441A can be lowered.

The feedback control may be, for example, PID control. In this case, the control of the supply flow rate of low DO DIW to be supplied to the immersing tank 441 (the inner tank 441A) can be performed by the duty control of the on-off valve provided in the flow adjustment portion 73. When the flow adjuster 73 includes a flow control valve having a variable stepless opening, the low DO DIW supply flow rate can be controlled by opening control of the flow control valve based on PID control.

The feedback control may be, for example, HIGH/LOW control (binary control). In this case, when the DO value (measured value) detected by the DO sensor 75 is lower than a predetermined threshold (for example, 100 ppb), the LOW DO DIW is supplied to the immersion tank 441 (the inner tank 441A) at a predetermined LOW flow rate (LOW) (for example, about 1 to 2L/min). When the DO value (measured value) is about to exceed a predetermined threshold value due to oxygen dissolving in DIW, low DO DIW is supplied to the immersing tank 441 at a HIGH flow rate (HIGH) (for example, 30L/min or more). The supply of DIW at a HIGH flow rate (HIGH) can be performed for a predetermined time determined by preliminary experiments. Alternatively, the DIW may be supplied at a HIGH flow rate (HIGH) until the DO value (measurement value) detected by the DO sensor 75 falls to a predetermined value (for example, about 50 ppb).

Before the substrate W is placed in the immersing tank 441 (the inner tank 441A), DO rises with time when the substrate W is placed in a state where DIW is retained in the inner tank 441A. In order to lower the DO from the excessively high state (for example, about 10000 ppb) to the above-described threshold value (for example, 100 ppb), a time of approximately 10 minutes (also depending on the capacity of the inner tank 441A) is sometimes required.

Therefore, when the immersing tank 441 (the inner tank 441A) is in a standby state (a state in which the substrate W is not placed), it is preferable to supply low DO DIW at a small flow rate (for example, about 1 to 2L/min) to suppress DO to about 5000ppb, for example. In this case, the time required for the DO to drop to the threshold (for example, 100 ppb) may be about 2 to 4 minutes (but also depends on the capacity of the inner tank 441A) (when the supply flow rate of the low DO DIW is about 40 to 80L/min). This can further suppress oxidation damage of the substrate W.

In the case of performing the above-described HIGH/LOW control (binary control) at the time of feedback control, the supply of LOW DO DIW may be performed at a LOW flow rate (LOW) for all the periods (including the period in the standby state) in which the supply of LOW DO DIW is not performed at a HIGH flow rate (HIGH).

The feedback control may be started from the time of placing the substrate W in the immersion tank 441 (the inner tank 441A) or may be started before the substrate W is placed in the inner tank 441A. In the former case, the consumption of low DO DIW can be reduced. In the latter case, the oxidation damage of the substrate W can be further suppressed. In addition, even when the substrate W is immersed in DIW having DO of about 5000ppb for about several minutes, oxidation, which is a problem, is not generated in many cases. Therefore, it is considered that there is no problem even if feedback control is started after the substrate W is placed in the immersion tank 441 (the inner tank 441A).

In the configuration example of fig. 11, low DO DIW is supplied to inner tank 441A, and the DIW in inner tank 441A overflows to outer tank 441B. Since oxygen is dissolved in DIW at the liquid surface of DIW stored in the inner tank 441A, it is considered that the overflow system in which DIW near the liquid surface flows out to the outer tank 441B is most preferable from the viewpoint of lowering DO.

However, the method of discharging DIW in the immersion tank 441 (inner tank 441A) is not limited to the overflow method. If the DIW whose DO in the inner tank 441A is relatively high is replaced with the DIW whose DO is relatively low, a method for realizing the discharge of the DIW is arbitrary. For example, a drain line may be connected to the immersion tank 441 (the inner tank 441A) to drain DIW from the drain line. Further, if the circulation line 444 as shown in fig. 2 is connected to the immersion tank 441, a drain line may be connected to the middle of the circulation line to drain DIW from the drain line.

Further, as shown in fig. 2, when DIW overflowed from inner tank 441A of immersion tank 441 to outer tank 441B is circulated so as to return to inner tank 441A via circulation line 444, dissolution of oxygen in the DIW can be promoted. Therefore, such a structure is not preferable in the case where only the reduction of dissolved oxygen is considered. However, when the DIW is circulated, the DIW can be easily warmed and filtered (particulate matter is removed), and therefore, if the warming and filtering are emphasized, the DIW can be circulated.

Furthermore, it is known that: when bare silicon was immersed in DIW with a DO of 40ppb, no growth of oxide film was observed for 1000 minutes or longer, and by applying the structure example 1, it was expected that oxidation inhibition of silicon could be achieved. In fact, even when DO was suppressed to 100ppb by the above-mentioned feedback control, the growth of an oxide film which was a problem was not confirmed. By controlling DO using the feedback control described above, consumption of DIW of low DO can be suppressed and oxidation of silicon can be suppressed.

Structural example 2

A configuration example of the standby unit 44 and the dipping tank 441 will be described with reference to fig. 12. In fig. 12, the same components as those shown in fig. 11 are given the same reference numerals. In the structure of fig. 12, one or more (two in the example of the figure) bubbling nozzles 80 are provided in addition to the structure of fig. 11 at the bottom of the immersing tank 441 (inner tank 441A). The bubbling nozzle 80 is formed of, for example, a tube in which a large number of gas ejection ports are provided along the arrangement direction of the substrates W. For example, N ₂ gas is supplied from a nitrogen (N ₂) gas supply source 81 provided as floor manager facilities to the bubbling nozzle 80 through a gas supply line 82. The gas supply line 82 is provided with a gas flow adjuster 83. The airflow adjuster 83 may be constituted by a single on-off valve, or may be constituted by a combination of an on-off valve, a flow rate control valve, a flow meter, and the like.

The nitrogen (N ₂) gas is discharged from the bubbling nozzle 80 so that fine bubbles derived from the N ₂ gas are substantially uniformly distributed in the DIW in the inner tank 441A and rise. By bubbling with N ₂ gas, dissolved oxygen can be discharged from DIW, and as a result, the DO value of DIW can be lowered.

Preferably, N ₂ gas bubbling is continuously performed at least while the substrate W is accommodated in the immersion tank 441 (the inner tank 441A). The bubbling of N ₂ gas may be started before the substrate W is placed in the dipping tank 441.

In the configuration example 2 shown in fig. 12, a structure for bubbling N ₂ gas is added to the configuration example 1, whereby the dissolved oxygen in DIW can be reduced more efficiently. In this case, the feedback control of the DO value may be performed by controlling only the supply amount (overflow amount) of the low DO DIW, and the N ₂ gas bubbling may be continued under a certain condition while the substrate W is accommodated in the immersion tank 441 (the inner tank 441A). To make the adjustment of the DO value, the condition of N ₂ gas bubbling (e.g., N ₂ gas ejection amount) may be changed based on the detection value of the DO sensor 75.

The DO value can also be controlled by bubbling N ₂ gas alone. In this case, the conditions under which the N ₂ gas is bubbled (e.g., the flow rate of the N ₂ gas) may be controlled based on the detection value of the DO sensor 75, for example, to obtain a desired DO value. In this case, in order to prevent the DIW in the immersing tank 441 (the inner tank 441A) from stagnating, the DIW may be continuously supplied from the liquid supply nozzle 74 at a small flow rate, for example.

The following experiment was performed to perform bubbling of N ₂ gas on DIW stored in the dipping tank 441 and confirm the change in DO. However, the immersion tank was not the immersion tank shown in fig. 12, but the experiment was performed using the immersion tank provided with the circulation line (444) shown in fig. 2. That is, overflow of DIW from the inner tank (441A) to the outer tank (441B) is always performed, and N ₂ bubbles are performed while circulating the DIW in the circulation line. In contrast to the DO of DIW before the start of N ₂ gas bubbling of about 7000ppb, DO was reduced to about 1000ppb after N ₂ bubbling for about 20 minutes. After that, DO hardly changed even if N ₂ bubbling was continued. In this experiment, DO can only be reduced to about 1000ppb. The inventors considered that this is because a large amount of oxygen is dissolved in DIW when overflowing from the inner tank to the outer tank. Therefore, the inventors considered that the DO value after bubbling N ₂ can be drastically lowered if the overflowed DIW can be prevented from being returned to the dipping tank.

Structural example 3

A configuration example 3 of the standby unit 44 and the dipping tank 441 will be described with reference to fig. 13. In fig. 13, the same reference numerals are given to the same components as those shown in fig. 11 and 12. In this configuration example 3, the bubbling nozzle 80 was connected to the CO ₂ supply source 84 to eject CO ₂ (carbon dioxide) gas from the bubbling nozzle 80. By bubbling with CO ₂ gas, dissolved oxygen can be vented from DIW, thereby lowering DO.

In the case of bubbling with CO ₂ gas, not only oxidation is made difficult by the decrease in DO, but also corrosion of a metal film (e.g., W (tungsten) film) can be suppressed by the decrease in pH of DIW. In this case, in addition to the DO sensor 75, a conductivity meter 85 for measuring the conductivity of DIW in the immersion tank 441 (the inner tank 441A) is provided, and the conditions under which CO ₂ gas bubbles (for example, the CO ₂ gas discharge amount) are controlled based on the detection value of the conductivity meter 85 so as to obtain a desired conductivity (for example, 1 μs/cm or more). In the case of CO ₂ water in which CO ₂ gas is dissolved in DIW, pH and conductivity are in one-to-one correspondence, and thus pH (amount of CO ₂ dissolved) can be controlled by the conductivity meter 85.

Preferably, CO ₂ gas bubbling is continuously performed at least while the substrate W is accommodated in the immersion tank 441 (the inner tank 441A). The CO ₂ gas bubbling may be started before the substrate W is placed in the dipping tank 441.

In the CO ₂ gas bubbling, low DO DIW supply from the liquid supply nozzle 74 may be performed in parallel. However, if the pH adjusting function by bubbling CO ₂ gas is emphasized, DIW is preferably supplied at a small flow rate. If bubbling of CO ₂ gas is performed for the purpose of removing dissolved oxygen in DIW, the supply flow rate of DIW is arbitrary. In this case, the control of DO of the DIW in the immersion tank 441 (the inner tank 441A) may be performed mainly by supplying the low DO DIW from the liquid supply nozzle 74, so as to assist in bubbling of the CO ₂ gas.

Control of DO or conductivity can also be performed by CO ₂ gas bubbling alone. In this case, for example, the condition of CO ₂ gas bubbling (for example, CO ₂ gas ejection amount) may be controlled based on the detection value of the DO sensor 75 or the detection value of the conductivity meter 85 so as to be a desired DO value or a desired conductivity. Further, if the amount of CO ₂ gas dissolved in DIW increases, both DO value and conductivity decrease, and since DO value and conductivity have a positive correlation, the conditions for bubbling CO ₂ gas can be controlled based on only one of DO value and conductivity. In this case, however, the other of the DO value and the conductivity is preferably monitored. In this case, too, it is not preferable that DIW stays in the immersing tank 441 (the inner tank 441A), and therefore, it is preferable to continuously supply DIW from the liquid supply nozzle 74 at a small flow rate, for example.

Instead of bubbling CO ₂ in the immersing tank 441 (inner tank 441A), CO ₂ water may be generated outside the inner tank 441A and supplied into the inner tank 441A through the liquid supply line 72 and the liquid supply nozzle 74. In order to produce CO ₂ water outside the inner tank 441A, a well-known CO ₂ water production apparatus may be used. Alternatively, CO ₂ may be dissolved in DIW supplied from a DIW supply source and supplied into the inner tank 441A by a hollow fiber membrane module provided in the liquid supply line 72.

When CO ₂ water is left in a state of being stored in the immersing tank 441 (inner tank 441A), CO ₂ escapes into the air around the tank 441A, and thus the CO ₂ concentration of CO ₂ water becomes low. When CO ₂ water is supplied from the outside of the inner tank 441A, in order to maintain the CO ₂ concentration of the CO ₂ water stored in the immersing tank 441 within a desired range, new CO ₂ water is supplied from the liquid supply nozzle 74 into the inner tank 441A, and the CO ₂ water in the inner tank 441A is discharged to the outer tank 441B by overflowing. The new supply amount of CO ₂ water may be adjusted by feedback control based on a deviation between the detection value of the conductivity meter 85 and the target value (for example, 0.5mΩ·cm). The feedback control can be performed by PID control or HIGH/LOW control (binary control) as described in the configuration example 1.

Structural example 4

A configuration example 4 of the standby unit 44 and the dipping tank 441 will be described with reference to fig. 14. In fig. 14, the same reference numerals are given to the same components as those shown in fig. 11. In this configuration example 4, hydrogen water (H ₂ -DIW) was supplied from the hydrogen water supply source 90 to the liquid supply nozzle 74 via the liquid supply line 72. Inside the immersion tank 441 (inner tank 441A), an oxidation-reduction potential (ORP) sensor 92 for measuring the oxidation-reduction potential (ORP) of hydrogen water (H ₂ water) is provided. As the hydrogen water supply source 90, a known commercially available hydrogen water supply device can be used. If the hydrogen water supply source 90 is provided as floor manager facilities, the hydrogen water supply source 90 may be utilized.

The hydrogen water supplied from the hydrogen water supply source 90 can be hydrogen water obtained by dissolving hydrogen in DIW at a concentration of about 1 to 2 ppm. Whereas pure water has an oxidation-reduction potential of approximately +700mV, hydrogen water having a hydrogen concentration of approximately 1 to 2ppm has an oxidation-reduction potential of approximately-200 mV to-300 mV. By reducing the oxidation-reduction potential in this manner, oxidation can be suppressed, and corrosion of a metal film (for example, a W (tungsten) film) can be suppressed. In addition, DO is also lowered by the hydrogen water production process, and thus oxidation can also be suppressed.

When the hydrogen water is left in a state of being stored in the immersing tank 441 (the inner tank 441A), the hydrogen escapes into the air around the immersing tank 441, and thus the hydrogen concentration in the hydrogen water becomes low. In order to maintain the hydrogen concentration of the hydrogen water stored in the immersing tank 441 within a desired range, new hydrogen water may be supplied from the liquid supply nozzle 74 into the inner tank 441A, and the hydrogen water in the inner tank 441A may be discharged to the outer tank 441B by flooding. Regarding the new hydrogen water supply amount, it is sufficient to adjust by feedback control based on the deviation of the detection value of the ORP sensor 92 from the target value (for example, -200 mV). The feedback control can be performed by PID control or HIGH/LOW control (binary control) as described in the configuration example 1.

Next, experiments performed to confirm the effects of CO ₂ water and hydrogen water will be described. The following steps are sequentially performed on a bare silicon wafer while the wafer is held on a rotary holding disk and rotated.

(1) Washing treatment with DHF (HF: diw=1:100): 25 ℃,60 seconds

(2) CO ₂ water rinse: 30 seconds

(3) And (5) rotary drying: 40 seconds

(4) Various test liquids (CO ₂ water, hydrogen water, DIW (27 ℃, DO about 5 ppb)) were supplied: 60 seconds

(5) And (5) rotary drying: 40 seconds

After the completion of the steps (3) and (5), the film thickness of the oxide film was measured using a spectroscopic ellipsometer.

The oxide film thickness immediately after the end of the step (3) is

When CO ₂ water is used in the step (4), the oxide film thickness after the completion of the step (5) is

When hydrogen water is used in the step (4), the oxide film thickness after the completion of the step (5) is the following

When DIW is used in the step (4), the oxide film thickness after the completion of the step (5) is set to be

From the above, it can be seen that: by immersing in CO ₂ water and hydrogen water, the effect of suppressing the growth of the natural oxide film is higher than that in the case of immersing in DIW.

In the case of applying the above-described configuration examples 1 to 4, the treatment liquid for hydrophilization treatment or the treatment liquid for zeta potential negative treatment may be supplied to the substrate W taken out of the dipping tank 441 using the spray nozzle 447 (see fig. 2 and 3).

The above-described configuration examples 1 to 4 are advantageous for the substrate W in which the materials (for example, silicon (Si) and the like) that become problems for oxidation and/or the materials (for example, tungsten (W), molybdenum (Mo), ruthenium (Ru) and the like) that become problems for dissolution (metal loss) are exposed to the surface (including the surface inside the concave portion of the pattern) after the series of processes in the batch processing section are completed.

The reason why the metal loss of tungsten is hardly generated by CO ₂ water and hydrogen water will be briefly described using the brabender diagram of fig. 15. The dissolution mechanism of tungsten described above is also known to be an environment in which WO ₄ ^2- (ionic state) is not easily formed. In CO ₂ water, the combination of redox potential (vertical axis of the brabender graph) and pH is in the region where H ₂WO₄ ² is stable. Thus, both DIW and hydrogen water (H ₂ -DIW) are in the region where WO ₄ ^2- is stable. However, since the oxidation-reduction potential of hydrogen water is lower than DIW, tungsten deposition is difficult to occur.

The presently disclosed embodiments are considered in all respects to be illustrative and not restrictive. The above-described embodiments may be omitted, substituted or altered in various ways without departing from the scope of the appended claims and their gist.

The substrate is not limited to the semiconductor wafer, and may be another type of substrate used in manufacturing a semiconductor device, such as a glass substrate and a ceramic substrate.

Description of the reference numerals

W: a substrate; 4: a batch processing section; 42: a batch processing unit; 44: a standby unit (standby unit); 441: an immersion tank; 51. 63: a transport system; 51: a first substrate transfer unit (third substrate transfer robot); 6: a single chip processing unit; 61. 62: and a single chip processing unit.

Claims

1. A substrate processing apparatus is provided with:

a batch processing section having a plurality of batch processing units, each of the batch processing units including a processing tank for storing a processing liquid, and performing liquid processing on a plurality of substrates at once by immersing the substrates in the processing liquid stored in the processing tank;

a single-wafer processing unit that includes a single-wafer processing unit that performs processing on the plurality of substrates processed by the batch processing unit one by one;

a standby unit having an immersion tank for storing an immersion liquid, the standby unit waiting the plurality of substrates processed by the batch processing unit while immersed in the immersion liquid; and

A transport system for transporting the plurality of substrates from the standby unit to the single-wafer processing unit, the transport system including a first substrate transport unit for taking out the plurality of substrates immersed in the immersion liquid in the immersion tank one by one from the immersion liquid,

Wherein the standby section is configured to be capable of performing at least one of a first liquid process and a second liquid process on the substrate,

The first liquid treatment is a liquid treatment for hydrophilizing the surface of the substrate or a liquid treatment for improving or maintaining the hydrophilicity of the surface of the substrate,

The second liquid treatment is a liquid treatment for making the electromotive potential of the surface of the substrate negative.

2. A substrate processing apparatus is provided with:

Wherein the standby section is configured to be capable of performing at least one of a first dipping treatment and a second dipping treatment on the substrate,

The first immersion treatment is a liquid treatment in which the substrate is immersed in water as the immersion liquid, the water being stored in the immersion tank and having a dissolved oxygen concentration controlled to be a predetermined value or less,

The second immersion treatment is a liquid treatment in which the substrate is immersed in hydrogen water or CO ₂ water stored in the immersion liquid as the immersion liquid.

3. The substrate processing apparatus according to claim 1, wherein,

The standby section is configured to be capable of performing both the first liquid treatment and the second liquid treatment,

The first liquid treatment is performed by immersing the plurality of substrates in a first treatment liquid stored in the immersion tank as the immersion liquid, the first treatment liquid being a liquid capable of hydrophilizing the surfaces of the substrates or capable of improving or maintaining the hydrophilicity of the surfaces of the substrates,

The standby unit further includes a treatment liquid nozzle, and the second liquid treatment is performed by supplying a second treatment liquid capable of making the electromotive potential of the surface of the substrate negative from the treatment liquid nozzle to the substrate during or immediately after the substrate is taken out from the immersion liquid by the first substrate carrying means.

4. The substrate processing apparatus according to claim 1, wherein,

The standby section is configured to be capable of performing the first liquid process,

The first liquid treatment is performed by immersing the plurality of substrates in a first treatment liquid stored in the immersion tank as the immersion liquid, wherein the first treatment liquid is a liquid capable of hydrophilizing the surfaces of the substrates or capable of improving or maintaining the hydrophilicity of the surfaces of the substrates.

5. The substrate processing apparatus according to claim 1, wherein,

The standby section is configured to be capable of performing the second liquid process,

The second liquid treatment is performed by immersing the plurality of substrates in a second treatment liquid stored in the immersion tank as the immersion liquid, wherein the second treatment liquid is a liquid capable of making the electromotive potential of the surfaces of the substrates negative.

6. The substrate processing apparatus according to claim 1, wherein,

The dipping tank is stored with pure water,

The standby unit further includes a treatment liquid nozzle, and the second liquid treatment is performed by supplying a second treatment liquid capable of making the electromotive potential of the surface of the substrate negative from the treatment liquid nozzle to the substrate during or immediately after the first substrate transfer unit is taken out from the immersion liquid.

7. The substrate processing apparatus according to claim 3 or 4, wherein,

The first treatment liquid is ozone water, SC2, sulfuric acid hydrogen peroxide water solution or hydrogen peroxide water.

8. The substrate processing apparatus according to any one of claims 3, 5 and 6, wherein,

The second treatment liquid is an alkaline liquid.

9. The substrate processing apparatus according to claim 8, wherein,

The alkaline solution is functional water containing ammonia, TMAH, namely tetramethyl ammonium hydroxide, or organic alkaline solution.

10. The substrate processing apparatus according to any one of claims 3, 5 and 6, wherein,

The second treatment fluid is an anionic surfactant.

11. The substrate processing apparatus according to claim 2, wherein,

The standby section is configured to be capable of performing the first dipping treatment,

The first immersion treatment is performed by immersing the plurality of substrates in pure water stored in the immersion tank and having a dissolved oxygen concentration of 100ppb or less.

12. The substrate processing apparatus according to claim 11, wherein,

The standby section includes a bubbling nozzle that ejects a gas for removing dissolved oxygen from the pure water stored in the immersion tank as bubbles.

13. The substrate processing apparatus according to claim 12, further comprising:

a dissolved oxygen concentration sensor that measures a concentration of dissolved oxygen in the pure water stored in the immersion tank; and

And a control unit for controlling a gas discharge operation of discharging gas from the bubbling nozzle so as to maintain a dissolved oxygen concentration of the pure water stored in the immersing tank at 100ppb or less.

14. The substrate processing apparatus according to claim 11, wherein,

The standby unit is provided with a low-dissolved-oxygen-concentration pure water supply device that supplies low-dissolved-oxygen-concentration pure water, which is pure water having a dissolved oxygen concentration of less than 100ppb, to the pure water stored in the immersion tank, so as to replace a part of the pure water stored in the immersion tank with the supplied low-dissolved-oxygen-concentration pure water.

15. The substrate processing apparatus according to claim 14, further comprising:

And a control unit for controlling the supply of pure water having a low dissolved oxygen concentration to the immersion tank so as to maintain the dissolved oxygen concentration of the pure water stored in the immersion tank at 100ppb or less.

16. The substrate processing apparatus according to claim 2, wherein,

The standby section is configured to be capable of performing the second dipping treatment,

The second immersion treatment is performed by immersing the plurality of substrates in CO ₂ water having a conductivity of less than 1mΩ·cm or hydrogen water having a dissolved hydrogen concentration of more than 1ppm stored in the immersion tank.

17. The substrate processing apparatus according to claim 1 or 2, wherein,

The transport system further includes: a substrate transfer unit that temporarily holds the substrate taken out of the immersion liquid by the first substrate conveyance unit; and a second substrate transfer unit that takes out the substrate from the substrate transfer unit and transfers the substrate to the single-wafer processing unit,

The substrate transfer unit includes: a mounting unit for mounting the substrate in a horizontal posture; and a liquid-covering nozzle that supplies a liquid-covering liquid to the substrate placed on the placement unit, and maintains a state in which at least a surface of the substrate is covered with the liquid.

18. The substrate processing apparatus according to claim 17, wherein,

The first substrate transfer unit is configured to take out the substrate immersed in the immersion liquid in the immersion tank in a vertical posture from the immersion liquid, change the substrate to a horizontal posture, and transfer the substrate to the substrate transfer unit in the horizontal posture,

The second substrate transfer unit transfers the substrate placed on the placement unit of the substrate transfer unit in a horizontal posture to the single-wafer processing unit of the single-wafer processing unit while maintaining the horizontal posture.

19. The substrate processing apparatus according to any one of claims 3 to 6, wherein,

The apparatus further comprises a circulation path connected to the immersion tank of the standby unit, and a pump and a thermostat provided in the circulation path, wherein the immersion liquid stored in the immersion tank is temperature-adjusted while being circulated in the circulation path.

20. A substrate processing method is performed by using a substrate processing apparatus,

The substrate processing apparatus includes:

In the substrate processing method, at least one of a first liquid process and a second liquid process is performed on the substrate in the standby section,

In the second liquid treatment, the electromotive potential of the surface of the substrate is set to be negative.

21. A substrate processing method is performed by using a substrate processing apparatus,

The substrate processing apparatus includes:

A batch processing section having a plurality of batch processing units, each of the batch processing units including a processing tank for storing a processing liquid, and performing liquid processing on a plurality of substrates at once by immersing the plurality of substrates in the processing liquid stored in the processing tank;

In the substrate processing method, a first dipping process or a second dipping process is performed on the substrate in the standby section,

The first immersion treatment is a treatment of immersing the substrate in the immersion liquid using water having a dissolved oxygen concentration controlled to be not more than a predetermined value as the immersion liquid,

In the second immersion treatment, the substrate is immersed in hydrogen water or CO ₂ water as the immersion liquid.

22. The substrate processing method according to claim 20, wherein,

Both the first liquid process and the second liquid process are performed in the standby section,

The first liquid treatment is performed by immersing the plurality of substrates in a first treatment liquid stored in the immersing tank, the first treatment liquid being capable of hydrophilizing the surfaces of the substrates or improving or maintaining the hydrophilicity of the surfaces of the substrates,

The second liquid treatment is performed by discharging a second treatment liquid capable of making the electromotive potential of the surface of the substrate negative from a treatment liquid nozzle provided in the standby section toward the substrate during or immediately after the first substrate transfer unit is taken out from the immersion liquid.

23. The substrate processing method according to claim 20, wherein,

The first liquid process is performed in the standby section,

The first liquid treatment is performed by immersing the plurality of substrates in a first treatment liquid stored in the immersion tank, the first treatment liquid being capable of hydrophilizing the surfaces of the substrates or improving or maintaining the hydrophilicity of the surfaces of the substrates.

24. The substrate processing method according to claim 20, wherein,

The second liquid process is performed in the standby section,

The second liquid treatment is performed by immersing the plurality of substrates in a second treatment liquid stored in the immersion tank and capable of making the electromotive potential of the surfaces of the substrates negative.

25. The substrate processing method according to claim 20, wherein,

The second liquid process is performed in the standby section,

The dipping tank stores pure water as the dipping liquid,

The second liquid treatment is performed by supplying a second treatment liquid capable of making the electromotive potential of the surface of the substrate negative to the substrate from a treatment liquid nozzle provided in the standby section during or immediately after the first substrate transfer unit is taken out from the immersion liquid.

26. The substrate processing method according to claim 21, wherein,

The first dipping process is performed in the standby section,

The first immersing treatment is performed by immersing the plurality of substrates in pure water stored in the immersing tank and having a dissolved oxygen concentration of 100ppb or less.

27. The substrate processing method according to claim 26, wherein,

In order to make the concentration of dissolved oxygen in the pure water stored in the immersion tank 100ppb or less, at least one of the following treatments is performed:

Bubbling with nitrogen, hydrogen or carbon dioxide gas to remove dissolved oxygen in the pure water; and

Supplying low-dissolved oxygen concentration pure water, which is pure water having a dissolved oxygen concentration of less than 100ppb, to the pure water stored in the immersing tank, and replacing a part of the pure water stored in the immersing tank with the supplied low-dissolved oxygen concentration pure water.

28. The substrate processing method according to claim 21, wherein,

The second dipping process is performed in the standby section,