SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

Abstract

This substrate processing device comprises: a batch processing section that has a plurality of batch processing units which perform a liquid treatment on a plurality of substrates in one batch in a treatment liquid stored in a treatment tank; a single-sheet processing section that performs processing on the substrates processed in the batch processing section, one substrate at a time; a holding section that holds substrates processed by the batch processing section in an immersion liquid in an immersion tank; and a conveyance system that includes a first substrate conveyance unit which removes the substrates one at a time from the immersion liquid, and that conveys each substrate from the holding section to the single-sheet processing section. The holding section performs, on the substrates, a first liquid treatment that hydrophilizes the substrate surface or that improves or maintains the hydrophilicity of the surface, and / or a second liquid treatment that makes the zeta potential of the substrate surface negative.

Description

[Technical Field]

[0001] The present disclosure relates to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] In the manufacture of semiconductor devices, substrates such as semiconductor wafers are subjected to liquid processing such as wet etching or cleaning by supplying a chemical solution to the substrate. Patent Document 1 describes a substrate processing system that performs such liquid processing on substrates. The substrate processing system includes a chemical tank, a water rinsing tank, a water rinsing buffer tank, a transfer unit, and a rotary dryer. The chemical tank performs batch-type chemical processing on multiple substrates, the water rinsing tank performs batch-type water rinsing on the multiple substrates after the chemical processing, and the rotary dryer performs single-substrate spin-off drying on each of the multiple substrates that have been subjected to water rinsing. The water rinsing buffer tank temporarily stores multiple substrates in water after water rinsing. The transfer unit transports the multiple substrates stored in the water rinsing buffer tank one by one to the rotary dryer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3192951 Summary of the Invention

[0004] The present disclosure provides a technique that can prevent deterioration of the surface condition of a substrate when the substrate is transported from a batch processing unit to a single-wafer processing unit.

[0005] A substrate processing apparatus according to an embodiment of the present disclosure is a batch processing apparatus having a plurality of batch processing units, each of which has a processing tank for storing a processing liquid and is configured to immerse a plurality of substrates in the processing liquid stored in the processing tank to collectively perform liquid processing on the plurality of substrates; a single wafer processing apparatus having a single wafer processing unit for processing the plurality of substrates processed by the batch processing apparatus one by one; and an immersion tank for storing an immersion liquid, which is configured to immerse the plurality of substrates processed by the batch processing apparatus in the single wafer processing unit. The system comprises: a waiting section that keeps the substrates immersed in immersion liquid while they wait; and a transport system that transports the plurality of substrates from the waiting section to the single wafer processing section, the transport system including a first substrate transport unit that removes the plurality of substrates immersed in the immersion liquid in the immersion tank one by one from the immersion liquid, wherein the waiting section is configured to perform at least one of a first liquid treatment and a second liquid treatment on the substrates, the first liquid treatment being a liquid treatment that makes the surface of the substrate hydrophilic or a liquid treatment that improves or maintains the hydrophilicity of the surface of the substrate, and the second liquid treatment being a liquid treatment that makes the zeta potential of the surface of the substrate negative.

[0006] According to the above-described embodiment of the present disclosure, it is possible to prevent deterioration of the surface condition of the substrate when the substrate is transported from the batch processing unit to the single wafer processing unit. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic cross-sectional view of a substrate processing system according to an embodiment of the substrate processing apparatus. [Figure 2] FIG. 2 is a schematic side view showing an example of the configuration of a standby unit and related devices. [Figure 3] FIG. 2 is a schematic plan view showing an example of the configuration of a standby unit and related devices. [Figure 4] FIG. 10 is a schematic front view for explaining the operation of the third substrate transport robot removing a substrate from a substrate holding part of the standby unit. [Figure 5]10 is a schematic front view for explaining an action when the substrate holder of the standby unit receives a substrate from the second substrate transport robot. FIG. [Figure 6] 1 is a schematic vertical cross-sectional view showing an example of the configuration of a single-wafer liquid processing unit. [Figure 7] FIG. 2 is a schematic vertical cross-sectional view showing an example of the configuration of a supercritical drying unit. [Figure 8] FIG. 2 is a schematic vertical cross-sectional view showing an example of the configuration of a substrate transfer unit. [Figure 9] 1 is a schematic cross-sectional view showing the structure of an object to be etched in a specific example 1 of a substrate processing method. [Figure 10] 10A to 10C are schematic cross-sectional views showing the structure of an object to be etched in specific examples 2 and 3 of the substrate processing method. [Figure 11] 10 is a schematic vertical cross-sectional view of an immersion tank showing a first configuration example of a standby section as another embodiment of the substrate processing apparatus. FIG. [Figure 12] FIG. 10 is a schematic vertical cross-sectional view of an immersion tank showing a second configuration example of a standby unit as another embodiment of the substrate processing apparatus. [Figure 13] FIG. 10 is a schematic vertical cross-sectional view of an immersion tank showing a third configuration example of a standby unit as another embodiment of the substrate processing apparatus. [Figure 14] FIG. 10 is a schematic vertical cross-sectional view of an immersion tank illustrating a fourth configuration example of a standby section as another embodiment of the substrate processing apparatus. [Figure 15] FIG. 1 is a Pourbaix diagram for explaining metal loss of tungsten. DETAILED DESCRIPTION OF THE INVENTION

[0008] A substrate processing system 1 according to an embodiment of the substrate processing apparatus of the present disclosure will be described below with reference to the accompanying drawings. To simplify the explanation of directions, an XYZ Cartesian coordinate system is set and displayed in the lower left corner of Fig. 1. The Z direction is the up-down direction, and the positive Z direction is the upward direction.

[0009] 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 loading / unloading section 2, a first interface section 3, a batch processing section 4, a second interface section 5, and a single wafer processing section 6.

[0010] The substrate processing system 1 includes a control device 100. The control device 100 is a computer and includes an arithmetic processing unit 101 and a storage unit 102. The storage unit 102 stores programs (including processing recipes) that control various processes executed in the substrate processing system 1. The arithmetic processing unit 101 reads and executes the programs stored in the storage unit 102 to control the operation of each component of the substrate processing system 1, which will be described later, and executes a series of processes, which will be described later. The control device 100 may include a user interface such as a keyboard, a touch panel, or a display. The program may be recorded on a computer-readable storage medium and installed from the storage medium into the storage unit 102 of the control device 100. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical disk (MO), and a memory card.

[0011] The container loading / unloading section 2 has a stage section 21 for placing a substrate transport container F such as a FOUP (hereinafter simply referred to as a "container F" for simplicity), and a container stock section 22 for storing the container F. The stage section 21 has a plurality of movable tables 211 (four in the illustrated example) arranged side by side in the Y direction. A partition wall 212 is provided between the stage section 21 and the container stock section 22. An opening with a shutter (not shown) is provided in the partition wall 212 at a position corresponding to each movable table 211. A container F placed on the movable table 211 can be moved into the container stock section 22 through the opening with the shutter open.

[0012] The container stock section 22 is provided with a plurality of container holding stages 221 and a container transport robot (container transport mechanism) 222. The container transport robot 222 can transport a container F between a movable table 211 located in the container stock section 22 and any of the container holding stages 221. Of the plurality of container holding stages 221, one (or two) on the first interface section 3 side is a substrate removal stage 221A, and the other is a substrate storage stage 221B.

[0013] A partition wall 223 is provided between the container stock section 22 and the first interface section 3. An opening with a shutter (not shown) and a mechanism for opening and closing the lid of the container F (not shown) are provided in the partition wall 223 at a position corresponding to the substrate removal stage 221A.

[0014] A first substrate transport robot (first transport mechanism) 31 is provided within the first interface section 3. The first substrate transport robot 31 has a plurality of (e.g., 5 to 25) substrate holders 32 as end effectors. The first substrate transport robot 31 collectively removes a plurality of (e.g., 5 to 25) substrates W from a container F placed on the substrate removal stage 221A and transfers them to a second substrate transport robot 41 (second transport mechanism) (shown by a dashed line) waiting in the transfer area 33. At this time, the first substrate transport robot 31 converts the substrates W stored in the container F in a horizontal position to a vertical position after removing them from the container F, and then transfers them to the second substrate transport robot 41.

[0015] It is also possible to process 50 substrates (two containers' worth) at a time in the batch processing unit 4. In this case, a pitch change mechanism for changing the distance between the substrate holders 32 may be provided on the end effector of the first substrate transport robot 31, or a pitch change mechanism may be provided in the transfer area 33. A pitch change mechanism is, for example, a mechanism for changing the arrangement distance (pitch) of the substrates W to half the arrangement distance when they are contained in the container F, and is well known in the technical field.

[0016] In the following description, it is assumed that one batch consists of 25 substrates W (25 substrates are simultaneously processed in each processing session in the batch processing section 4).

[0017] The batch processing section 4 is provided with a plurality of batch processing units 42. While four batch processing units 42 are depicted in FIG. 1, the number of batch processing units 42 is not limited to four, and the number of batch processing units 42 provided corresponds to the number of processes to be performed on the substrates W. The plurality of batch processing units 42 have roughly the same basic configuration, each including a processing tank that stores a processing liquid, a substrate holder (referred to as a wafer boat, for example) that holds the substrates in the processing tank, and a lifting mechanism that raises and lowers the substrate holder. The substrate holder can hold, for example, 25 substrates W in a vertical position at equal intervals in the horizontal direction. The plurality of batch processing units 42 are lined up in the X direction.

[0018] The multiple batch processing units 42 may include general-purpose batch processing units capable of handling a wide variety of processes, as well as batch processing units dedicated to specific processes. An example of the latter is a batch processing unit for phosphoric acid (H3PO4) processing. In phosphoric acid processing, the processing liquid in the processing tank is typically heated to a high temperature and brought to a nearly boiling state, and bubbling may also be performed. To accommodate such processing, a batch processing unit for phosphoric acid processing is additionally provided with, for example, a lid for closing the top opening of the processing tank, a mechanism for monitoring and maintaining the boiling state of the processing liquid, a bubbling nozzle, a mechanism for pressing the substrate against the substrate holder, and the like.

[0019] The plurality of batch processing units 42 include, for example, a first chemical liquid processing unit, a first rinse processing unit, a second chemical liquid processing unit, and a second rinse processing unit. The substrate W is sequentially loaded into the first chemical liquid processing unit, the first rinse processing unit, the second chemical liquid processing unit, and the second rinse processing unit, and is subjected to a process (chemical liquid processing or DIW rinse processing) according to the liquid stored in the processing tank in each batch processing unit 42. Specific examples of the processes performed in the batch processing units 42 will be described later.

[0020] A cleaning unit 43 is provided in the batch processing unit 4 at a position closest to the first interface unit 3, for cleaning the substrate holder 413 of the second substrate transport robot 41 and drying it as required.

[0021] A standby unit (standby section) 44 is provided at a position farthest from the first interface section 3 in the batch processing section 4. The standby unit 44 includes an immersion tank 441 that stores the immersion liquid in which the substrates W are immersed, a substrate holder 442 (also called a wafer boat) that holds the substrates in the immersion tank 441, and a movement mechanism 443 that raises and lowers the substrate holder 442 and moves it horizontally (see FIGS. 2 and 3). The substrate holder 442 can hold, for example, 25 substrates W in a vertical position and equidistantly spaced horizontally. The standby unit 44 performs a process to change the surface condition of the substrates W in preparation for subsequent single-substrate transfer. Specifically, this process is, for example, a hydrophilization process to prevent the surface of the substrate W from running out of liquid, or a process to negatively adjust the zeta potential of the surface of the substrate W to prevent particles from adhering to the surface of the substrate W. The detailed configuration of the standby unit 44 will be described later.

[0022] The processing liquid stored in the batch processing unit 42, into which the substrate W is loaded immediately before being loaded into the waiting unit 44, must not interfere with the processing performed in the waiting unit 44, and is usually a rinse liquid, specifically, for example, DIW.

[0023] The batch processing section 4 is provided with the above-mentioned second substrate transport robot 41. The second substrate transport robot 41 has guide rails 411 extending along the arrangement direction (X direction) of the plurality of batch processing units 42, a running body 412 that can run along the guide rails 411, and a substrate holder 413 attached to the running body 412.

[0024] The substrate holding unit 413 has, for example, three substrate holding rods 414 extending in the Y direction. Each substrate holding rod 414 has substrate holding grooves (not shown) arranged at equal intervals along the Y direction. The peripheral edges of the substrates W fit into each substrate holding groove, allowing the substrate holding unit 413 to hold 25 substrates W in a vertical position at equal intervals along the Y direction.

[0025] One end of the guide rail 411 extends to the front of the transfer area 33 in the first interface section 3. Therefore, as described above, substrates can be transferred between the first substrate transport robot 31 and the second substrate transport robot 41 at the transfer area 33. The other end of the guide rail 411 extends to the front of the standby unit 44. Therefore, the second substrate transport robot 41 can transfer substrates between the standby unit 44 and any batch processing unit 42. In addition, the substrate holder 413 of the second substrate transport robot 41 can access the cleaning unit 43 to clean the substrate holder 413.

[0026] A third substrate transport 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, they can be stacked one on top of the other, for example.

[0027] The third substrate transport robot 51 can take out the substrates W held by the substrate holders 442 one by one in the immersion tank 441 of the waiting unit 44, convert the substrates W from a vertical position to a horizontal position, and then place them on the substrate transfer unit 52.

[0028] 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 that perform supercritical drying on the substrates W processed in the single wafer liquid processing units 61, and a fourth substrate transport robot 63. When a plurality of single wafer liquid processing units 61 and supercritical drying units 62 are provided, they can be stacked, for example, one on top of the other. The single wafer liquid processing units 61 and supercritical drying units 62 are single wafer processing units that process one substrate W at a time.

[0029] The fourth substrate transfer robot 63 is equipped with an end effector that can move, for example, in the X and Y directions, move up and down in the Z direction, and rotate about a vertical axis using a multi-axis drive mechanism 631. The end effector is, for example, a fork-shaped substrate holder 632 that can hold a single substrate. The fourth substrate transfer robot 63 can transfer substrates between the substrate transfer unit 52 in the second interface section 5, the single-wafer liquid processing unit 61, the supercritical drying unit 62, and the substrate transfer unit 35 in the first interface section 3. While being transferred by the fourth substrate transfer robot 63, the substrate W is always maintained in a horizontal position.

[0030] Any single-wafer liquid processing unit 61 known in the technical field of semiconductor manufacturing equipment can be used. A configuration example of a single-wafer liquid processing unit 61 that can be used in this embodiment will be briefly described below with reference to FIG. 6 . The single-wafer liquid processing unit 61 includes a spin chuck 611 that can hold a substrate W in a horizontal position and rotate it about a vertical axis, and one or more nozzles 612 that discharge a processing liquid onto the substrate W held and rotating by the spin chuck 611. The nozzles 612 are supported by an arm 613 that moves the nozzles 612. The single-wafer liquid processing unit 61 includes a liquid receiving cup 614 that collects the processing liquid that has splashed from the rotating substrate W. The liquid receiving cup 614 includes a liquid drain port 615 for discharging the collected processing liquid to the outside of the single-wafer liquid processing unit 61 and an exhaust port 616 for discharging the atmosphere inside the liquid receiving cup 614. Clean gas (clean air) is blown downward from fan filter unit 618 provided on the ceiling of chamber 617 of single wafer liquid processing unit 61 , drawn into liquid receiving cup 614 , and discharged through exhaust port 616 .

[0031] In this embodiment, the fourth substrate transport robot 63 removes the substrate W from the substrate transfer unit 52 in the second interface section 5 and loads it into the single-wafer liquid processing unit 61. In the single-wafer liquid processing unit 61, a DIW rinse process, an IPA replacement process, and an IPA puddle formation process are sequentially performed. In the DIW rinse process, DIW is supplied from the nozzle 612 to the surface of the rotating substrate W, and the liquid previously adhering to the surface of the substrate W is washed away with the DIW. In the IPA replacement process, IPA is supplied from the nozzle 612 to the surface of the rotating substrate W, and the DIW on the surface of the substrate W is replaced with IPA. In the IPA puddle formation process, IPA continues to be supplied from the nozzle 612 while the rotation speed of the substrate is significantly reduced to form a relatively thick IPA liquid film on the surface of the substrate W, and then the rotation of the substrate is stopped.

[0032] Any supercritical drying unit known in the technical field of semiconductor manufacturing equipment can be used as the supercritical drying unit 62. An example of the configuration and operation of the supercritical drying unit 62 that can be used in this embodiment will be briefly described below with reference to FIG. 7. The supercritical drying unit 62 has a supercritical chamber 621 and a substrate support tray 622 that can be advanced into and retreated from the supercritical chamber 621. FIG. 1 shows the substrate support tray 622 having been withdrawn from the supercritical chamber 621, and in this state the fourth substrate transport robot 63 transfers the substrate W to and from the substrate support tray 622.

[0033] The substrate W on which the IPA puddle has been formed is removed from the single-wafer liquid processing unit 61 by the fourth substrate transfer robot 63 and placed on a substrate support tray 622 of the supercritical drying unit 62. Next, the substrate support tray 622 is housed in the supercritical chamber 621, and a lid 625 integral with the substrate support tray 622 seals the supercritical chamber 621. In this state, a supercritical fluid (e.g., supercritical carbon dioxide (CO2)) is supplied into the supercritical chamber 621 from a supercritical fluid supply source (not shown) through a supply port 623, flows along the arrows in the figure, and is discharged from a discharge port 624. Note that CO2 may be supplied through another supply port (not shown) opening toward the underside of the substrate support tray 622 until the pressure inside the supercritical chamber 621 is increased. The IPA on the substrate W is replaced with supercritical CO2 flowing nearby. After the IPA has been replaced with supercritical CO2, the pressure inside the supercritical chamber 621 is returned to normal. This vaporizes the supercritical CO2, drying the surface of the substrate W. In this way, the substrate W can be dried while preventing the pattern formed on the surface of the substrate W from collapsing.

[0034] The dried substrate is removed from the supercritical drying unit 62 by the fourth substrate transport robot 63 and carried into the substrate transfer unit 35 provided in the first interface section 3. The first substrate transport robot 31 in the first interface section 3 removes the substrate W from the substrate transfer unit 35 and stores the processed substrate W in a container F placed on the substrate storage stage 221B.

[0035] The container F containing the processed substrates W is placed on the movable table 211 by the container transport robot 222 of the container stock section 22, and is carried out to the stage section .

[0036] Next, an example of the configuration and operation of the batch processing unit 4 (particularly the standby unit 44) and the second interface unit 5 will be described in detail with reference to FIGS. 2 to 5 and 8. FIG.

[0037] 2 and 3, the second substrate transport robot 41 and the third substrate transport robot 51 are depicted together with the standby unit 44.

[0038] As described above, the standby unit 44 has an immersion tank 441. The immersion tank 441 has an inner tank 441A that stores immersion liquid and an outer tank 441B that receives immersion liquid that overflows from the inner tank 441A. The immersion liquid that flows out into the outer tank 441B flows into a circulation line 444 and is discharged toward the substrates W from a nozzle 445 provided in the inner tank 441A. The nozzle 445 may be a bar nozzle having discharge ports arranged at equal intervals along the arrangement direction of the substrates W in the inner tank 441A. A pump for forming a circulating flow, a filter for removing particles, and a temperature regulator, such as a heater, for regulating the temperature of the immersion liquid are installed in the circulation line 444.

[0039] As described above, the standby unit 44 has a substrate holder 442 that holds substrates in the immersion bath 441. The substrate holder 442 has a flat base 442A that extends vertically (Z direction) and two sets of support members 442B that extend horizontally (Y direction) from the base 442A. Each set of support members 442B has two support rods 442C whose base ends are fixed to the base 442A and a fixing member 442D that fixes the ends of the two support rods 442C to each other. Each support rod 442C has substrate holding grooves (not shown) that are formed at equal intervals in the Y direction and that receive the peripheral edge of the substrate W to position the substrate W in the Y direction. The substrate holder 442 can hold a plurality of substrates W, for example, 25 substrates W, in a vertical position at equal intervals in the Y direction.

[0040] The standby unit 44 has a movement mechanism 446 that can move the substrate holder 442 in the Y direction and the Z direction. The movement mechanism 446 can move the substrate holder 442 between a transfer position (shown by a two-dot chain line in FIG. 2) where the substrate can be transferred to and from the second substrate transport robot 41, and an immersion position (shown by a solid line in FIG. 3) where the held substrate W is immersed in the immersion liquid stored in the immersion tank 441.

[0041] 5, the two sets of support members 442B of the substrate holder 442 of the standby unit 44 can pass through the gaps between the three substrate holding rods 414 that make up the substrate holding section 413 of the second substrate transport robot 41. Therefore, by moving the substrate holder 442 (support members 442B) and the substrate holding section 413 (substrate holding rods 414) relatively in the Z direction, multiple substrates W can be transferred collectively between the support members 442B and the substrate holding rods 414.

[0042] The arrows in Fig. 5 indicate the relative movement in the vertical direction between the support member 442B and the holding rod 413A. When the substrate holding rod 414, indicated by a filled circle in Fig. 5, is positioned further above the support member 442B, the substrate W that was held by the support member 442B begins to be held by the substrate holding rod 414. By performing the relative movement in the opposite direction to the above, the substrate W that was held by the substrate holding rod 414 begins to be held by the support member 442B.

[0043] As is clear from the above description, the configuration of the standby unit 44 is the same as that of a batch-type liquid processing apparatus known in the art. In other words, the configuration of the batch processing unit 42 in this embodiment may be the same as that of the standby unit 44, and the transfer of substrates W between the batch processing unit 42 and the second substrate transport robot 41 can also be performed in the same way. For this reason, a description of the configuration of the batch processing unit 42 will be omitted. The main differences between the batch processing unit 42 and the standby unit 44 are that not only the second substrate transport robot 41 but also the third substrate transport robot 51 can access the standby unit 44, and the liquid stored in the tank.

[0044] The third substrate transfer robot 51 is configured as a single-wafer transfer robot. The end effector of the third substrate transfer robot 51 is configured as a single thin substrate holder 511. In the illustrated embodiment, the substrate holder 511 has a base portion 511A and a pair of elongated tip portions 511B connected to the base portion 511A. Each tip portion 511B has a dimension that allows it to be inserted between two support rods 442C that make up each support member 442B of the substrate holder 442 (see FIG. 4).

[0045] 2 and 4, the substrate holder 511 has a plurality of (three in the illustrated example) gripping claws 512A, 512B (schematically shown by dotted circles in FIG. 4). In the illustrated example, a movable gripping claw 512A is provided at the tip of a base portion 511A of the substrate holder 511, and fixed gripping claws 512B are provided at the tip of each tip portion 511B. The gripping claws 512A, 512B have a shape that allows them to engage with the peripheral edge of the substrate W (the region near the APEX).

[0046] 2 and 3, the substrate holder 511 is brought close to the substrate W in the Y direction, and the movable gripping claws 512A are moved away from the fixed gripping claws 512B, with the movable gripping claws 512A and the fixed gripping claws 512B positioned slightly away from the peripheral edge of the substrate W. From this state, the movable gripping claws 512A are moved closer to the fixed gripping claws 512B, thereby clamping the substrate W with the movable gripping claws 512A and the fixed gripping claws 512B. Next, by moving the substrate holder 511 straight up (in the positive Z direction), the peripheral edge of the substrate W is pulled out from the substrate holding groove (not shown) of the support rod 442C of the substrate holder 442, and the substrate W can be removed.

[0047] The third substrate transport robot 51 may be configured as a multi-axis robot (e.g., one having an X-axis, a Y-axis, a Z-axis, and a θ-axis) or as an articulated robot, as long as it is configured to satisfy the following functions (1) and (2). (1) Any substrate W held by the substrate holder 442 in the inner tank 441A can be removed from the inner tank 441A by moving it vertically (positive Z direction) while it is clamped by the substrate holder 511. (2) The substrate W, which has been in a vertical position in the inner tank 441A, can be converted to a horizontal position and placed on the substrate transfer unit 52. 1 to 3, the third substrate transport robot 51 configured as an articulated robot is shown schematically.

[0048] As shown in FIGS. 2 and 3, a spray nozzle 447 may be attached to the immersion tank 441. The spray nozzle 447 can be moved in the Y direction by a Y-direction movement mechanism 448 (shown only in FIG. 3) slightly above the surface of the immersion liquid stored in the inner tank 441A. The spray nozzle 447 can spray the spray liquid onto the surface of the substrate W while it is being pulled up from the immersion liquid by the third substrate transport robot 51 or immediately after it has been pulled up. The spray nozzle 447 is preferably configured to spray the spray liquid evenly onto the surface of the substrate W. The spray nozzle 447 can be configured, for example, as a bar nozzle having outlets arranged at equal intervals along the X direction. In this case, the spray nozzle 447 sprays the spray liquid onto the surface of the substrate W while being positioned by the Y-direction movement mechanism 448 in close proximity to and facing the surface of the substrate W being pulled up by the third substrate transport robot 51.

[0049] The third substrate transport robot 51 transfers the substrate W removed from the immersion bath 441 to a horizontal position, and then transfers the substrate W into the substrate transfer unit 52. The substrate transfer unit 52 is a unit that mediates the transfer of the substrate W between the third substrate transport robot 51 and the fourth substrate transport robot 63. An example of the configuration of the substrate transfer unit 52 is shown schematically in Figure 8. The third substrate transport robot 51, the substrate transfer unit 52, and the fourth substrate transport robot 63 form a transport system that transports the substrate W from the batch processing unit 4 (standby unit 44) to the single wafer processing unit 6.

[0050] The substrate transfer unit 52 has a plurality of (e.g., three) support pins 521 as substrate support members. The third substrate transport robot 51 loads the substrate W into the substrate transfer unit 52 through a loading entrance 522 and places the substrate W on the support pins 521 in a horizontal position. A coating liquid nozzle 523 that discharges a coating liquid onto the surface of the substrate W is provided on the ceiling of the substrate transfer unit 52. The coating liquid nozzle 523 supplies the coating liquid so that a puddle (liquid film) of the coating liquid is formed over the entire surface of the substrate W. The coating liquid is, for example, DIW, but is not limited to this and may be a processing liquid for zeta potential negative processing, which will be described later.

[0051] A liquid film thickness sensor (not shown) or a camera (not shown) may be provided on the ceiling of the substrate transfer unit 52, and the coating liquid may 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 about to run out 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 has been retained in the substrate transfer unit 52 for a long enough time that there is a risk that the surface of the substrate W will dry out (meaning that at least a part of the surface will be exposed to the atmosphere). In this case, the retention time of the substrate W in the substrate transfer unit 52 may be measured by a timer. In the above case, the control device 100 causes the coating liquid to be discharged from the coating liquid nozzle 523 onto the substrate W based on the detection result of the sensor or camera, or the time measurement result of the timer.

[0052] When the single-wafer liquid processing unit 61 into which the substrate W is to be loaded becomes available for substrate loading, the substrate W placed in the substrate transfer unit 52 is removed by the fourth substrate transport robot 63 through the unloading port 524 and loaded into the single-wafer liquid processing unit 61. The path that the substrate W follows thereafter is as described above.

[0053] Next, we will explain the liquid (immersion liquid, spray liquid) supplied to the substrate W in the standby unit 44 and the liquid (coating liquid) supplied to the substrate W in the substrate transfer unit 52. Problems that may arise during transport from the batch processing unit 4 to the single wafer processing unit 6 include the following.

[0054] If the surface of a substrate W has become hydrophobic after the final chemical treatment performed on the substrate W in the batch treatment unit 4, the liquid may run out while the substrate is being transported from the batch treatment unit 4 to the single wafer treatment unit 6, resulting in a portion of the substrate surface being exposed. Exposure of the substrate surface may result in the collapse of the pattern on the substrate surface or the occurrence of defects such as particles and water marks on the substrate surface (Problem 1).

[0055] If the surface of the substrate W is positively charged after the last chemical treatment performed on the substrate W in the batch processing unit 4, the possibility of particles floating in the liquid adhering to the substrate increases (because the zeta potential of the particles and the zeta potential of the substrate surface are opposite) (Problem 2).

[0056] In this embodiment, a liquid treatment for solving at least one of the above problems 1 and 2 is carried out in the standby unit 44.

[0057] The liquid treatment to solve the above problem 1 is a treatment to make the surface of the substrate hydrophilic (hereinafter referred to as "hydrophilization treatment" for simplicity). Because the hydrophilization treatment takes a relatively long time, it is performed by immersing the substrate in an immersion liquid (treatment liquid for hydrophilization treatment) stored in an immersion tank 441 of the standby unit 44. For example, any of the following can be used as the treatment liquid for hydrophilization treatment. - SC2 - Ozone water - Hydrogen peroxide (H2O2) - SPM (sulfuric acid peroxide) Which of these is to be used can be determined taking into consideration the processing liquid used in the final chemical processing (excluding the DIW rinse processing, which is the final step) executed in the batch processing unit 4, the surface condition of the substrate W after processing (the material of the exposed surface, the chemical state (whether or not it has a hydrophilic group at the end, etc.)), etc. See the specific examples of processing described later.

[0058] In this embodiment, at least 25 substrates are simultaneously immersed in the hydrophilic treatment solution in the immersion tank 441 and then removed one by one. In other words, the immersion time for the first substrate removed is significantly different from that for the last substrate removed. Therefore, the hydrophilic treatment solution must not etch the substrate surface to a problematic level. From the viewpoint of etching suppression, the temperature of the hydrophilic treatment solution is preferably room temperature (however, it is not limited to room temperature).

[0059] The liquid treatment to solve the above problem 2 is a treatment in which a liquid (liquid film) capable of making the zeta potential of the surface of the substrate negative is applied to the surface of the substrate W (hereinafter, for simplicity, referred to as "zeta potential negativity treatment"). The zeta potential negativity treatment is effective in a shorter time than the hydrophilic treatment, so it may be performed by immersing the substrate in an immersion liquid (treatment liquid for zeta potential negativity treatment) in an immersion tank 441, or by spraying a spray liquid (treatment liquid for zeta potential negativity treatment) onto the surface of the substrate using a spray nozzle 447.

[0060] As the treatment solution for the zeta potential negative treatment, for example, any of the following can be used. - Functional water (e.g. DIW containing trace amounts of ammonia water) - TMAH (Tetramethylammonium hydroxide) - Organic alkaline solution - Anionic surfactants The temperature of the treatment solution for the zeta potential negative treatment is preferably room temperature from the viewpoint of suppressing etching (however, it is not limited to room temperature).

[0061] For example, if the final chemical liquid treatment performed in the batch processing unit 4 is an SC1 treatment (followed by a DIW rinse treatment), the surface of the substrate W may be sufficiently hydrophilic when the substrate W is placed in the standby unit 44. In such a case, only the zeta potential negative treatment may be performed in the standby unit 44. In this case, the zeta potential negative treatment may be performed using the spray nozzle 447. Even in this case, since the substrate W must not be exposed to the air during standby, it is possible to use an appropriate non-reactive liquid, such as DIW, as the immersion liquid in the immersion tank 441 and have the substrate wait in the immersion liquid. Of course, the zeta potential negative treatment may also be performed using the immersion liquid in the immersion tank 441 (a treatment liquid for the zeta potential negative treatment).

[0062] However, even if the surface of the substrate W is hydrophilic at the time the substrate W is loaded into the waiting unit 44, a treatment liquid for hydrophilic treatment may be stored in the immersion tank 441 to further enhance the hydrophilicity or to perform a treatment that at least maintains the hydrophilicity.

[0063] As described above, the following advantageous effects are obtained by the surface of the substrate W being hydrophilized when it leaves the standby unit 44 and by the zeta potential of the surface of the substrate W being negative.

[0064] Since the surface of the substrate W is hydrophilized when it leaves the standby unit 44, it is possible to prevent liquid from running out on the surface of the substrate W (loss of the liquid film on the entire or part of the substrate surface) when the substrate W is pulled up from the immersion liquid in the immersion tank 441. It is also possible to prevent liquid from running out on the surface of the substrate W while the substrate W is being transported from the batch processing unit 4 to the single wafer processing unit 6. This makes it possible to prevent defects such as particles or water marks from occurring on the surface of the substrate, or pattern collapse, caused by the surface of the substrate W being exposed to the atmosphere.

[0065] Conversely, according to the above embodiment, problems are unlikely to arise even if the transport distance or transport time from the batch processing unit 4 to the single-wafer processing unit 6 is somewhat longer. This means that optimal layouts can be adopted for each of the batch processing unit 4 and the single-wafer processing unit 6. In other words, it is no longer necessary to adopt an unreasonable layout in order to shorten the transport distance or transport time. Furthermore, in many cases, it is difficult to perfectly synchronize the processing schedules for batch processing and single-wafer processing, and some waiting time must be set before the substrate W is loaded into the single-wafer processing unit. According to the above embodiment, liquid shortage on the surface of the substrate W is unlikely to occur, so some waiting time is unlikely to cause problems. This improves flexibility in setting the transport schedule and processing schedule. Furthermore, if a transfer unit 52 equipped with a coating liquid nozzle 523 is provided between the batch processing unit 4 and the single-wafer processing unit 6, the possibility of liquid shortage on the surface of the substrate W during transport from the batch processing unit 4 to the single-wafer processing unit 6 can be further reduced.

[0066] Furthermore, because the zeta potential of the surface of the substrate W is negative when the substrate W leaves the standby unit 44, it is possible to prevent or significantly suppress particles contained in the liquid film on the surface of the substrate W from adhering to the surface of the substrate W while the substrate W is being transported from the batch processing unit 4 to the single wafer processing unit 6. This also eliminates the need to adopt an unreasonable layout in order to shorten the transport distance or transport time, and improves flexibility in setting transport schedules and processing schedules (because particle adhesion due to zeta potential also tends to increase over time).

[0067] As described above, according to this embodiment, when the substrates W are transported from the batch processing section 4 to the single wafer processing section 6, the surface condition of the substrates W can be prevented from deteriorating.

[0068] Specific examples of combinations of the treatments performed in each treatment unit of the batch treatment section 4 and the hydrophilization treatment and / or zeta potential negative treatment performed in the standby unit 44 will be described below.

[0069] <Example 1> In Example 1, as shown in FIG. 9, selective etching of the SiN film of a substrate W having a SiO2 / SiN stacked structure of 3D-NAND is performed in the batch processing unit 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 using high-temperature phosphoric acid in the first batch processing unit 42, and then a DIW rinse process is performed in the second batch processing unit 42. Next, a process of removing etching residues using SC1 is performed in the third batch processing unit 42, and finally a DIW rinse process is performed in the fourth batch processing unit 42. The substrates are then transported to the waiting unit 44 and immersed in a waiting solution, and then removed one by one by the third substrate transport robot 51 and transported to the single-wafer processing unit 6, where they are dried according to the procedure described above.

[0070] In this specific example 1, the surface of the substrate after processing (including the surface inside the recesses) is almost entirely hydrophilic SiO2, and the hydrophilicity is further enhanced by the processing by SC1 in the third batch processing unit 42, so that hydrophilization processing in the standby unit 44 is not necessary. Therefore, only the zeta potential negative processing needs to be performed in the standby unit 44. For example, a processing liquid for zeta potential negative processing (e.g., weakly alkaline functional water) may be stored in the immersion tank 441, and the substrate may be immersed in this. In this case, the spray nozzle 447 does not need to be used. The processing liquid for zeta potential negative processing may also be supplied to the substrate W in the substrate transfer unit 52.

[0071] <Example 2> In Example 2, as shown in FIG. 10, the batch processing unit 4 performs partial selective etching of the SiN film of a substrate W having a Si / SiO2 / SiN stacked structure that constitutes a cell transistor module of a 3D-DRAM (the left side of FIG. 10 shows the state before etching, and the right side shows the state after etching). In this case, first, the first batch processing unit 42 performs selective etching of the SiN film using high-temperature phosphoric acid, and then the second batch processing unit 42 performs DIW rinsing. The substrates are then transported to the waiting unit 44 and immersed in a waiting solution. Then, the third substrate transport robot 51 removes the substrates one by one and transports them to the single-wafer processing unit 6, where they are dried according to the procedure described above. Note that after the processing in the second batch processing unit 42, the third batch processing unit 42 may perform etching residue removal processing using SC1, followed by DIW rinsing processing in the fourth batch processing unit 42. However, such processing is not performed here.

[0072] In this specific example 2, the surface of the substrate after processing (including the surface inside the recesses) will contain a mixture of hydrophobic Si, hydrophilic SiO2, and semi-hydrophobic SiN, but in reality, the entire surface of the substrate appears hydrophobic to semi-hydrophobic due to the hydrophobic Si. This makes the liquid prone to run out. For this reason, hydrophilization processing is performed in the standby unit 44. Specifically, for example, a processing liquid for hydrophilization processing (e.g., ozone water) may be stored in an immersion tank 441, and the substrate W may be immersed in this.

[0073] <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. Specifically, SiN is also exposed on the surface of the substrate W (including the surface of the recesses). The SiN surface is covered with DIW (pH 6 to 7) and has a surface potential close to neutral, making it susceptible to particle adsorption. Therefore, to make the potentials of the SiN surface and the particles repel each other, a zeta potential negative treatment is performed in the standby unit 44 to make the two have the same sign. The zeta potential negative treatment can be performed by spraying a treatment liquid for zeta potential negative treatment onto the substrate W from the spray nozzle 447. Both the hydrophilization treatment and the zeta potential negative treatment may be performed in the standby unit 44. In this case, it is preferable to perform the hydrophilization treatment in the immersion tank 441 and then the zeta potential negative treatment using the spray nozzle 447. If the hydrophilization treatment is not performed in the standby unit 44, the zeta potential negative treatment can also be performed in the immersion tank 441.

[0074] Next, we will explain another embodiment of the liquid processing that can be performed in the standby unit 44. This other embodiment solves the problem that can arise when the substrate W remains in the immersion tank 441 for a long period of time.

[0075] After a plurality of substrates W (e.g., 25 or 50 substrates) are loaded into the immersion tank 441 of the standby unit 44, the substrates W are removed one by one from the immersion tank 441 for transport to the single wafer processing unit 6. The residence time of the first substrate W removed from the immersion tank 441 and the last substrate W removed therefrom differs considerably (e.g., by several hours). When the immersion liquid is DIW, the dissolved oxygen in the DIW may oxidize or dissolve the surface of the substrate W (e.g., bare silicon constituting the substrate W, or a metal layer, such as tungsten wiring, exposed on the surface of the substrate W). The following two experiments confirmed that, when the immersion liquid is DIW, the dissolved oxygen in the DIW may oxidize or dissolve the surface of the substrate W (e.g., bare silicon constituting the substrate W, or a metal layer, such as tungsten wiring, exposed on the surface of the substrate W).

[0076] [Experiment 1] A bare silicon substrate was subjected to a DHF chemical cleaning to remove the native oxide film, followed by a DIW rinse. The bare silicon substrate was then immersed in DIW (dissolved oxygen concentration (DO) of approximately 5000 ppb) in an immersion tank with a configuration similar to that of the immersion tank 441 shown in FIG. 11. The thickness of the native oxide film on the bare silicon substrate surface was approximately 4 Å without DIW immersion (immediately after the DIW rinse), approximately 6.4 Å after 3 hours of DIW immersion, and approximately 7 Å after 5 hours of DIW immersion. It can be seen that the native oxide film gradually grows when bare silicon is immersed in DIW for a long period of time. DIW with a DO of approximately 5000 ppb can be obtained by continuously supplying low-DO DIW at a low flow rate (e.g., approximately 1 to 2 L / min) into the immersion tank 441, as described in Configuration Example 1 below.

[0077] The bare silicon substrate was cleaned with DHF chemical solution to remove the native oxide film, then rinsed with DIW, and finally dried before being placed in a FOUP (Foup Transport Container). The thickness of the native oxide film on the bare silicon substrate surface was approximately 4 Å immediately after placement in the FOUP, and approximately 4.8 Å 6.2 hours after placement in the FOUP.

[0078] From the above, it can be seen that immersion in DIW (DO of about 5000 ppb) promotes the growth of native oxide films compared to storage in a FOUP.

[0079] [Experiment 2] A test was conducted in which a substrate with a tungsten film formed on its surface was immersed in DIW (with a DO concentration of approximately 5000 ppb) using the same immersion tank as in Experiment 1. The thickness of the tungsten film was reduced by approximately 1.5 to 2.5 Å after 3 hours of DIW immersion, and approximately 2.5 to 4.2 Å after 5 hours of DIW immersion. This shows that prolonged immersion in DIW causes a non-negligible amount of dissolution of the tungsten film.

[0080] The inventors believe that the dissolution of the tungsten film occurs through the following reaction. <Oxidation> W + 2H2O ⇒ WO2 + 2H2 W + O2 ⇒ WO2 As oxidation progresses further, WO2 becomes WO3 <Dissolution> WO3 + H2O ⇒ H2WO4 H2WO4 + H2O ⇒ H3O + + HWO4 - HWO4 - + OH - ⇒ WO4 2-

[0081] DIW provided as a factory utility typically has a dissolved oxygen concentration (DO) of approximately 5 ppb. If such low-DO DIW is stored in the immersion tank 441 and left unattended, oxygen contained in the air surrounding the immersion tank 441 dissolves into the DIW, and the DO may increase to over 10,000 ppb. Furthermore, if DIW is allowed to overflow from the immersion tank 441 and circulated back to the immersion tank 441, the dissolution of oxygen into the DIW tends to be accelerated. DIW with a relatively high dissolved oxygen content can result in oxidation or dissolution (metal loss) due to the above-mentioned mechanisms. The configuration of the standby unit 44, which can solve this problem, is described below with reference to Figures 11 to 14.

[0082] [Configuration example 1] A first configuration example of the standby unit 44 and the immersion tank 441 will be described with reference to Fig. 11. For the configuration of the standby unit 44 and the immersion tank 441, please also refer to Fig. 2. The same components as those shown in Fig. 2 are designated by the same reference numerals.

[0083] A liquid supply nozzle 74 for supplying DIW is provided in the inner tank 411A of the immersion tank 441. DIW is supplied to the liquid supply nozzle 74 via a liquid supply line 72 whose upstream end is connected to a DIW supply source 71 serving as a factory utility. A flow adjustment unit 73 is provided in the liquid supply line 72. The flow adjustment unit 73 can be configured, for example, from a single on-off valve, or can be configured from a combination of an on-off valve, a flow control valve, a flow meter, etc.

[0084] Generally, a DIW supply source provided as a factory utility in a semiconductor device manufacturing factory supplies DIW with low DO (e.g., less than 5 ppb). Therefore, it is usually not necessary to provide a dedicated low-DO DIW supply device to realize Configuration Example 1. However, in some cases, a dedicated low-DO DIW supply device may be provided for the substrate processing system 1.

[0085] Inner tank 411A of immersion tank 441 is provided with a DO sensor 75 for detecting the DO value of the DIW stored in inner tank 411A.

[0086] A drain line 76 is connected to the bottom of the outer tank 411B of the immersion tank 441. The drain line 76 is connected to a factory wastewater system. A plurality of drain lines 76 may be provided at different locations in the outer tank 411B.

[0087] The operation of Configuration Example 1 will be described. A plurality of substrates W, for example, 25 substrates W, that have undergone the final batch processing (for example, rinsing after chemical processing) are transferred by the second substrate transport robot 41 from the batch processing unit 42 that performed the final processing on the substrates W to the standby unit 44, and are then introduced into the immersion tank 441 (inner tank 441A) all at once. Thereafter, the third substrate transport robot 51 transfers the substrates W one by one from the inner tank 441A. If the DIW is left stagnating in the inner tank 441A, oxygen in the air surrounding the inner tank 441A will dissolve into the DIW, causing the DO value of the DIW to increase over time.

[0088] To prevent the DO value from exceeding a predetermined threshold and to suppress the consumption of DIW, feedback control is performed, for example, under the control of the control device 100 (see FIG. 1). Here, the threshold DO value is a DO value, for example, 100 ppb, that prevents problematic oxidation from occurring in the substrate W that is last removed from the inner bath 441A among the substrates W collectively loaded into the immersion bath 441 (inner bath 441A). The threshold can be decreased (increased), for example, if the longest residence time of the substrates W in the inner bath 441A is increased (shortened).

[0089] 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 the deviation between the DO value (measured value) detected by the DO sensor 75 and a target DO value, e.g., 100 ppb. During normal operation, the inner tank 441A is filled with DIW, and an amount of DIW equal to the amount of low-DO DIW supplied from the liquid supply nozzle 74 overflows from the inner tank 441A to the outer tank 441B. This replaces some of the DIW with a relatively high DO with DIW with a relatively low DO (e.g., less than 5 ppb). This allows the DO of the DIW in the inner tank 441A to be reduced. The higher the supply flow rate of the low-DO DIW, the more rapidly the DO of the DIW in the inner tank 441A can be reduced.

[0090] The feedback control may be, for example, PID control. In this case, the supply flow rate of the low-DO DIW to the immersion tank 441 (inner tank 441A) may be controlled by duty control of an on-off valve provided in the flow adjustment unit 73. If the flow adjustment unit 73 includes a continuously variable flow control valve, the supply flow rate of the low-DO DIW may be controlled by controlling the aperture of the flow control valve using PID control.

[0091] 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 (e.g., 100 ppb), low-DO DIW is supplied to the immersion tank 441 (inner tank 441A) at a predetermined low flow rate (LOW) (e.g., approximately 1 to 2 L / min). Then, when oxygen dissolves in the DIW and the DO value (measured value) approaches the predetermined threshold, low-DO DIW is supplied to the immersion tank 441 at a high flow rate (HIGH) (e.g., 30 L / min or higher). DIW can be supplied at a high flow rate (HIGH) for a predetermined period determined by preliminary experiments. Alternatively, DIW can be supplied at a high flow rate (HIGH) until the DO value (measured value) detected by the DO sensor 75 falls to a predetermined value (e.g., approximately 50 ppb).

[0092] If the DIW is left stagnating in the inner tank 441A before the substrate W is placed in the immersion tank 441 (inner tank 441A), the DO level will increase over time. In order to reduce the DO level from an excessively high level (for example, about 10,000 ppb) to the above threshold level (for example, 100 ppb), it may take nearly 10 minutes (depending on the capacity of the inner tank 441A).

[0093] For this reason, it is preferable to suppress the DO to, for example, about 5000 ppb by supplying low-DO DIW at a low flow rate (for example, about 1 to 2 L / min) to the immersion tank 441 (inner tank 441A) even when the tank is in a standby state (when no substrates W are loaded). In this way, it takes only about 2 to 4 minutes (when the supply flow rate of low-DO DIW is about 40 to 80 L / min) to reduce the DO to the above threshold (for example, 100 ppb) (depending on the capacity of the inner tank 441A). This further suppresses oxidation damage to the substrates W.

[0094] When the above-mentioned HIGH / LOW control (binary control) is performed during feedback control, DIW with low DO may be supplied at a low flow rate (LOW) during all time periods when DIW with high flow rate (HIGH) and low DO is not being supplied (including time periods when the system is in standby mode).

[0095] The above feedback control may be started after the substrate W is placed in the immersion tank 441 (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, oxidation damage to the substrate W can be further suppressed. Note that even if the substrate W is immersed in DIW with a DO of, for example, about 5000 ppb for several minutes, in most cases, no problematic oxidation occurs. For this reason, it is considered that there is no problem even if the feedback control is started after the substrate W is placed in the immersion tank 441 (inner tank 441A).

[0096] 11, low-DO DIW is supplied to the inner tank 441A, and the DIW in the inner tank 441A is overflowed into the outer tank 441B. Because oxygen dissolves in the DIW at the liquid surface of the DIW stored in the inner tank 441A, the overflow method in which the DIW near the liquid surface flows out into the outer tank 441B is considered to be the most preferable from the viewpoint of reducing DO.

[0097] However, the method for discharging the DIW in the immersion tank 441 (inner tank 441A) is not limited to the overflow method. Any method can be used to replace the relatively high-DO DIW in the inner tank 441A with relatively low-DO DIW. For example, a drain line may be connected to the immersion tank 441 (inner tank 441A), and the DIW may be discharged from this drain line. Furthermore, if the circulation line 444 shown in FIG. 2 is connected to the immersion tank 441, a drain line may be connected midway through the circulation line, and the DIW may be discharged from this drain line.

[0098] 2, circulating the DIW that has overflowed from inner tank 441A to outer tank 441B of immersion tank 441 back to inner tank 441A via circulation line 444 promotes dissolution of oxygen into the DIW. For this reason, adopting such a configuration is not preferable if only consideration is given to reducing dissolved oxygen. However, circulating the DIW makes it possible to easily control the temperature of the DIW, filter the DIW (remove particles), and so on, so if this is important, circulating the DIW may be acceptable.

[0099] It is already known that when bare silicon is immersed in DIW with a DO of 40 ppb, no oxide film growth is observed for over 1,000 minutes, and it is expected that the application of Configuration Example 1 will achieve the suppression of silicon oxidation. In fact, even when the DO was suppressed to 100 ppb using the above feedback control, no problematic oxide film growth was observed. By controlling the DO using the above feedback control, it is possible to suppress silicon oxidation while suppressing the consumption of low-DO DIW.

[0100] [Configuration example 2] A first configuration example of the standby unit 44 and the immersion tank 441 will be described with reference to FIG. 12. In FIG. 12, the same components as those shown in FIG. 11 are denoted by the same reference numerals. The configuration of FIG. 12 includes, in addition to the configuration of FIG. 11, one or more (two in the illustrated example) bubbling nozzles 80 provided at the bottom of the immersion tank 441 (inner tank 441A). The bubbling nozzle 80 may be formed, for example, by a pipe having a number of gas outlets provided along the arrangement direction of the substrates W. N2 gas is supplied to the bubbling nozzle 80 via a gas supply line 82 from a nitrogen (N2) gas supply source 81 provided, for example, as factory utility power. A flow adjustment unit 83 is provided in the gas supply line 82. The flow adjustment unit 83 may be formed, for example, by a single on-off valve, or may be formed by a combination of an on-off valve, a flow control valve, a flow meter, etc.

[0101] Nitrogen (N2) gas is discharged from the bubbling nozzle 80 so that minute bubbles derived from the N2 gas rise while being distributed roughly evenly throughout the DIW in the inner tank 441A. Bubbling with N2 gas expels dissolved oxygen from the DIW, thereby lowering the DO value of the DIW.

[0102] It is preferable that the N2 gas bubbling be performed continuously at least while the substrate W is accommodated in the immersion tank 441 (inner tank 441A). The N2 gas bubbling may be started before the substrate W is placed in the immersion tank 441.

[0103] 12 shows a second configuration example in which a configuration for N2 gas bubbling is added to the first configuration example, thereby enabling more efficient reduction of dissolved oxygen in the DIW. In this case, feedback control of the DO value is performed only by controlling the supply amount (overflow amount) of low-DO DIW, and N2 gas bubbling may be performed continuously under constant conditions while the substrate W is accommodated in the immersion tank 441 (inner tank 441A). To adjust the DO value, the conditions for N2 gas bubbling (e.g., the amount of N2 gas discharged) may be changed based on the detection value of the DO sensor 75.

[0104] The DO value can also be controlled only by N2 gas bubbling. In this case, the conditions of N2 gas bubbling (e.g., the flow rate of N2 gas) may be controlled so as to obtain a desired DO value, for example, based on the detection value of DO sensor 75. In this case, DIW may be continuously supplied from liquid supply nozzle 74 at, for example, a small flow rate to prevent DIW from accumulating in immersion tank 441 (inner tank 441A).

[0105] An experiment was conducted to confirm the change in DO by bubbling N2 gas through DIW stored in the immersion tank 441. However, the immersion tank used was not the one shown in FIG. 12, but rather the one equipped with the circulation line (444) shown in FIG. 2. Specifically, N2 gas bubbling was performed while constantly overflowing DIW from the inner tank (441A) to the outer tank (441B) and circulating DIW through the circulation line. The DO of the DIW before the N2 gas bubbling was approximately 7000 ppb. After approximately 20 minutes of N2 gas bubbling, the DO decreased to approximately 1000 ppb. Thereafter, continued N2 gas bubbling showed almost no change in DO. In this experiment, the DO could only be reduced to approximately 1000 ppb. The inventors believe that this is due to the relatively large amount of oxygen dissolved in the DIW when it overflowed from the inner tank to the outer tank. Therefore, the inventors believe that if the overflowed DIW is not returned to the immersion tank, the DO value after N2 bubbling can be significantly reduced.

[0106] [Configuration example 3] A third configuration example of the standby unit 44 and the immersion tank 441 will be described with reference to Fig. 13. In Fig. 13, the same components as those shown in Figs. 11 and 12 are denoted by the same reference numerals. In this third configuration example, a bubbling nozzle 80 is connected to a CO2 supply source 84, and CO2 (carbon dioxide) gas is discharged from the bubbling nozzle 80. Bubbling with CO2 gas expels dissolved oxygen from the DIW, thereby lowering the DO.

[0107] Bubbling with CO2 gas not only reduces oxidation by lowering the DO, but also reduces the pH of the DIW, thereby suppressing corrosion of metal films (e.g., tungsten (W) films). In this case, in addition to the DO sensor 75, an electrical conductivity meter 85 may be provided to measure the electrical conductivity of the DIW in the immersion tank 441 (inner tank 441A). The CO2 gas bubbling conditions (e.g., the CO2 gas discharge rate) may be controlled based on the value detected by the electrical conductivity meter 85 to obtain a desired electrical conductivity (e.g., 1 μS / cm or higher). In the case of CO2 water, in which CO2 gas is dissolved in DIW, pH and electrical conductivity correspond one-to-one, so the pH (amount of dissolved CO2) can be controlled using the electrical conductivity meter 85.

[0108] It is preferable that the CO 2 gas bubbling be performed continuously at least while the substrate W is accommodated in the immersion tank 441 (inner tank 441A). The CO 2 gas bubbling may be started before the substrate W is placed in the immersion tank 441.

[0109] While CO2 gas bubbling is being performed, low DO DIW may be supplied from the liquid supply nozzle 74 in parallel. However, if the pH adjustment function of CO2 gas bubbling is emphasized, it is preferable to supply DIW at a small flow rate. If the purpose of CO2 gas bubbling is to remove dissolved oxygen from the DIW, the DIW supply flow rate is arbitrary. In this case, the DO of the DIW in the immersion tank 441 (inner tank 441A) may be controlled primarily by supplying low DO DIW from the liquid supply nozzle 74, with CO2 gas bubbling being used as an auxiliary.

[0110] The DO value or electrical conductivity can also be controlled solely by CO2 gas bubbling. In this case, the CO2 gas bubbling conditions (e.g., CO2 gas discharge rate) can be controlled based on the detection value of the DO sensor 75 or the detection value of the electrical conductivity meter 85 to achieve the desired DO value or electrical conductivity. Note that as the amount of CO2 gas dissolved in the DIW increases, both the DO value and electrical conductivity decrease. Because there is a positive correlation between the DO value and electrical conductivity, the CO2 gas bubbling conditions can be controlled based solely on either the DO value or electrical conductivity. However, in this case, it is preferable to monitor the other of the DO value and electrical conductivity. Even in this case, it is undesirable for the DIW to stagnate in the immersion tank 441 (inner tank 441A), so it is preferable to continue supplying DIW from the liquid supply nozzle 74, for example, at a small flow rate.

[0111] Instead of performing CO2 bubbling in the immersion tank 441 (inner tank 441A), CO2 water may be generated outside the inner tank 441A and supplied to the inner tank 441A via the liquid supply line 72 and the liquid supply nozzle 74. A known CO2 water production device may be used to produce CO2 water outside the inner tank 441A. Alternatively, a hollow fiber membrane module provided in the liquid supply line 72 may dissolve CO2 in DIW supplied from a DIW supply source, and the resulting solution may be supplied to the inner tank 441A.

[0112] If CO2 water is left stored in the immersion tank 441 (inner tank 441A), CO2 is released into the air surrounding the inner tank 441A, causing the CO2 concentration of the CO2 water to decrease. To maintain the CO2 concentration of the CO2 water stored in the immersion tank 441 within a desired range when CO2 water is supplied from outside the inner tank 441A, new CO2 water is supplied into the inner tank 441A from the liquid supply nozzle 74, and the CO2 water in the inner tank 441A is discharged to the outer tank 441B by overflow. The amount of new CO2 water supplied can be adjusted by feedback control based on the deviation between the value detected by the electrical conductivity meter 85 and the target value (e.g., 0.5 MΩ cm). Feedback control can be performed using PID control or HIGH / LOW control (binary control), as described in Configuration Example 1.

[0113] [Configuration example 4] A fourth configuration example of the standby unit 44 and the immersion tank 441 will be described with reference to FIG. 14. In FIG. 14, the same components as those shown in FIG. 11 are designated by the same reference numerals. In this fourth configuration example, hydrogen water (H2-DIW) is supplied to the liquid supply nozzle 74 from a hydrogen water supply source 90 via a liquid supply line 72. An ORP sensor 92 for measuring the oxidation-reduction potential (ORP) of the hydrogen water (H2 water) is provided inside the immersion tank 441 (inner tank 441A). A publicly known, commercially available hydrogen water supply device can be used as the hydrogen water supply source 90. If the hydrogen water supply source 90 is provided as a factory utility, it may be used.

[0114] The hydrogen water supplied from the hydrogen water source 90 can be DIW with hydrogen dissolved at a concentration of about 1 to 2 ppm. While the oxidation-reduction potential of pure water is approximately +700 mV, the oxidation-reduction potential of hydrogen water with a hydrogen concentration of about 1 to 2 ppm is approximately -200 mV to -300 mV. By lowering the oxidation-reduction potential in this way, oxidation can be suppressed, and corrosion of metal films (e.g., W (tungsten) films) can be suppressed. Note that the DO is also reduced during the hydrogen water production process, which also suppresses oxidation.

[0115] If hydrogen water is left stored in the immersion tank 441 (inner tank 441A), hydrogen will be released into the air surrounding the immersion tank 441, causing the hydrogen concentration in the hydrogen water to decrease. To maintain the hydrogen concentration of the hydrogen water stored in the immersion tank 441 within a desired range, new hydrogen water is supplied into the inner tank 441A from the liquid supply nozzle 74, and the hydrogen water in the inner tank 441A is discharged by overflow into the outer tank 441B. The amount of new hydrogen water supplied can be adjusted by feedback control based on the deviation between the detection value of the ORP sensor 92 and a target value (e.g., −200 mV). Feedback control can be performed by PID control or HIGH / LOW control (binary control), as described in Configuration Example 1.

[0116] The following describes an experiment conducted to confirm the effects of CO2 water and hydrogen water. A bare silicon wafer was rotated on a wafer spin chuck, and the following steps were carried out in sequence. (1) Cleaning with DHF (HF:DIW=1:100): 25°C, 60 seconds (2) CO2 water rinse: 30 seconds (3) Spin drying: 40 seconds (4) Supply of various test liquids (CO2 water, hydrogen water, DIW (27°C, DO approx. 5 ppb)): 60 seconds (5) Spin drying: 40 seconds After the steps (3) and (5), the thickness of the oxide film was measured using a spectroscopic ellipsometer. The thickness of the oxide film immediately after the end of step (3) was 2.669 Å. When CO2 water was used in step (4), the oxide film thickness after step (5) was 2.608 Å. When hydrogen water was used in step (4), the oxide film thickness after step (5) was 3.263 Å. When DIW was used in step (4), the oxide film thickness after step (5) was 4.201 Å. From the above, it can be seen that immersion in CO2 water and hydrogen water is more effective in suppressing the growth of native oxide films than immersion in DIW.

[0117] Even when the above configuration examples 1 to 4 are applied, a spray nozzle 447 (see Figures 2 and 3) may be used to supply a treatment liquid for hydrophilic treatment or a treatment liquid for zeta potential negative treatment to the substrate W removed from the immersion tank 441.

[0118] The above configuration examples 1 to 4 are useful for substrates W on which, after a series of processes in a batch processing unit is completed, materials that are susceptible to oxidation (e.g., silicon (Si) etc.) and / or materials that are susceptible to dissolution (metal loss) (e.g., tungsten (W), molybdenum (Mo), ruthenium (Ru) etc.) are exposed on the surface (including the surface within the recesses of the pattern).

[0119] The reason why CO2 water and hydrogen water make it difficult for metal loss to occur in tungsten will be briefly explained using the Pourbaix diagram in Figure 15. As can be seen from the tungsten dissolution mechanism explained earlier, WO4 2- In CO2 water, the combination of the oxidation-reduction potential (vertical axis of the Pourbaix diagram) and pH is H2WO4 2 is in the stable region. Therefore, both DIW and hydrogen water (H2-DIW) are in the stable region. 2- However, since the oxidation-reduction potential of hydrogen water is lower than that of DIW, tungsten is less likely to be eluted.

[0120] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0121] The substrate is not limited to a semiconductor wafer, but may be any other type of substrate used in the manufacture of semiconductor devices, such as a glass substrate or a ceramic substrate. [Explanation of symbols]

[0122] W substrate 4 Batch Processing Unit 42 batch processing units 44 Standby section (standby unit) 441 Soaking tank 51,63 Transport system 51 First substrate transfer unit (third substrate transfer robot) 6 Single wafer processing section 61,62 Single wafer processing unit

Claims

1. a batch processing section having a plurality of batch processing units, each of which has a processing tank for storing a processing liquid, and which is configured to immerse a plurality of substrates in the processing liquid stored in the processing tank and perform liquid processing on the plurality of substrates at once; a single wafer processing section including a single wafer processing unit that processes the plurality of substrates processed by the batch processing section one by one; a standby unit having an immersion tank for storing an immersion liquid, and for allowing the plurality of substrates processed by the batch processing unit to wait in a state immersed in the immersion liquid; a transfer system that transfers the plurality of substrates from the standby unit to the single wafer processing unit, the transfer system including a first substrate transfer unit that removes the plurality of substrates immersed in the immersion liquid in the immersion tank one by one from the immersion liquid; Equipped with the waiting section is configured to perform at least one of a first liquid treatment and a second liquid treatment on the substrate; the first liquid treatment is a liquid treatment that makes the surface of the substrate hydrophilic, or a liquid treatment that improves or maintains the hydrophilicity of the surface of the substrate, the second liquid treatment is a liquid treatment that makes the zeta potential of the surface of the substrate negative; Substrate processing equipment.

2. a batch processing section having a plurality of batch processing units, each of which has a processing tank for storing a processing liquid, and which is configured to immerse a plurality of substrates in the processing liquid stored in the processing tank and perform liquid processing on the plurality of substrates at once; a single wafer processing section including a single wafer processing unit that processes the plurality of substrates processed by the batch processing section one by one; a standby unit having an immersion tank for storing an immersion liquid, and for allowing the plurality of substrates processed by the batch processing unit to wait in a state immersed in the immersion liquid; a transfer system that transfers the plurality of substrates from the standby unit to the single wafer processing unit, the transfer system including a first substrate transfer unit that removes the plurality of substrates immersed in the immersion liquid in the immersion tank one by one from the immersion liquid; Equipped with the waiting section is configured to perform at least one of a first immersion treatment and a second immersion treatment on the substrate; the first immersion treatment is a liquid treatment in which the substrate is immersed in water as the immersion liquid stored in the immersion tank, the water being controlled so that the dissolved oxygen concentration is equal to or less than a predetermined value; The second immersion treatment is carried out by immersing the substrate in hydrogen water or CO 2 as the immersion liquid. ２ A liquid treatment in which the substrate is immersed in water. Substrate processing equipment.

3. the standby unit is configured to be able to perform 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 as the immersion liquid stored in the immersion tank, and the first treatment liquid is a liquid that can hydrophilize the surfaces of the substrates or improve or maintain the hydrophilicity of the surfaces of the substrates; 2. The substrate processing apparatus of claim 1, wherein the waiting section further has a processing liquid nozzle, and the second liquid processing is performed by supplying a second processing liquid capable of making the zeta potential of the surface of the substrate negative from the processing liquid nozzle to the substrate while the substrate is being removed from the immersion liquid by the first substrate transport unit or immediately after it is removed.

4. the standby section is configured to perform the first liquid treatment, 2. The substrate processing apparatus according to claim 1, wherein the first liquid processing is performed by immersing the plurality of substrates in a first processing liquid as the immersion liquid stored in the immersion tank, and the first processing liquid is a liquid that can hydrophilize the surfaces of the substrates or improve or maintain the hydrophilicity of the surfaces of the substrates.

5. the standby section is configured to perform the second liquid treatment, 2. The substrate processing apparatus according to claim 1, wherein the second liquid processing is performed by immersing the plurality of substrates in a second processing liquid as the immersion liquid stored in the immersion tank, and the second processing liquid is a liquid that can make the zeta potential of the surface of the substrates negative.

6. the standby section is configured to perform the second liquid treatment, The immersion tank stores pure water, 2. The substrate processing apparatus of claim 1, wherein the waiting section further has a processing liquid nozzle, and the second liquid processing is performed by supplying a second processing liquid capable of making the zeta potential of the surface of the substrate negative from the processing liquid nozzle to the substrate while the substrate is being removed from the immersion liquid by the first substrate transport unit or immediately after the substrate is removed.

7. 5. The substrate processing apparatus according to claim 3, wherein the first processing liquid is ozone water, SC2, SPM, or hydrogen peroxide water.

8. The substrate processing apparatus according to claim 3 , wherein the second processing liquid is an alkaline liquid.

9. 9. The substrate processing apparatus according to claim 8, wherein the alkaline liquid is functional water containing ammonia, TMAH (tetramethylammonium hydroxide), or an organic alkaline solution.

10. The substrate processing apparatus according to claim 3 , wherein the second processing liquid is an anionic surfactant.

11. the standby section is configured to perform the first immersion treatment, 3. The substrate processing apparatus according to claim 2, wherein the first immersion process is performed by immersing the plurality of substrates in pure water stored in the immersion tank and having a dissolved oxygen concentration of 100 ppb or less.

12. The substrate processing apparatus according to claim 11 , wherein the standby section includes a bubbling nozzle that ejects gas in the form of bubbles to remove dissolved oxygen from the pure water stored in the immersion tank.

13. a dissolved oxygen concentration sensor that measures the dissolved oxygen concentration in the pure water stored in the immersion tank; a control unit that controls the gas discharge operation from the bubbling nozzle so that the dissolved oxygen concentration of the pure water stored in the immersion tank is maintained at 100 ppb or less; The substrate processing apparatus of claim 12 further comprising:

14. 12. The substrate processing apparatus of claim 11, wherein the standby section includes 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 100 ppb, into the pure water stored in the immersion tank and replaces a portion of the pure water stored in the immersion tank with the supplied low-dissolved oxygen concentration pure water.

15. a dissolved oxygen concentration sensor that measures the dissolved oxygen concentration in the pure water stored in the immersion tank; a control unit that controls the supply of pure water with a low dissolved oxygen concentration to the immersion tank so that the dissolved oxygen concentration of the pure water stored in the immersion tank is maintained at 100 ppb or less; The substrate processing apparatus of claim 14 further comprising:

16. the standby section is configured to perform the second immersion treatment, The second immersion treatment is carried out by immersing CO 2 having an electrical conductivity of less than 1 MΩ cm stored in the immersion tank. ２ The substrate processing apparatus according to claim 2 , wherein the treatment is performed by immersing the plurality of substrates in water or hydrogen water having a dissolved hydrogen concentration of more than 1 ppm.

17. the transfer system further includes a substrate transfer unit that temporarily holds the substrate removed from the immersion liquid by the first substrate transfer unit, and a second substrate transfer unit that removes the substrate from the substrate transfer unit and transfers it to the single-wafer processing unit, 3. The substrate processing apparatus according to claim 1, wherein the substrate transfer unit comprises: a platform on which the substrate is placed in a horizontal position; and a coating liquid nozzle that supplies a coating liquid to the substrate placed on the platform to maintain at least a surface of the substrate covered with the liquid.

18. the first substrate transport unit takes the substrate, which is immersed in a vertical position in the immersion liquid in the immersion tank, out of the immersion liquid while the substrate remains in the vertical position, converts the substrate to a horizontal position, and carries the substrate into the substrate transfer unit in the horizontal position; 18. The substrate processing apparatus according to claim 17, wherein the second substrate transport unit transports the substrate, which is placed in a horizontal position on the placement portion of the substrate transfer unit, into the single-wafer processing unit of the single-wafer processing section while maintaining the horizontal position.

19. 7. The substrate processing apparatus according to claim 3, further comprising a circulation path connected to the immersion tank in the standby section, and a pump and a temperature regulator interposed in the circulation path, wherein the immersion liquid stored in the immersion tank is temperature-regulated while circulating through the circulation path.

20. a batch processing section having a plurality of batch processing units, each of which has a processing tank for storing a processing liquid, and which is configured to immerse a plurality of substrates in the processing liquid stored in the processing tank and perform liquid processing on the plurality of substrates at once; a single wafer processing section including a single wafer processing unit that processes the plurality of substrates processed by the batch processing section one by one; a standby unit having an immersion tank for storing an immersion liquid, and for allowing the plurality of substrates processed by the batch processing unit to wait in a state immersed in the immersion liquid; a transfer system that transfers the plurality of substrates from the standby unit to the single wafer processing unit, the transfer system including a first substrate transfer unit that removes the plurality of substrates immersed in the immersion liquid in the immersion tank one by one from the immersion liquid; A substrate processing method performed using a substrate processing apparatus comprising: In the waiting section, the substrate is a first liquid treatment which is a liquid treatment for making the surface of the substrate hydrophilic or for improving or maintaining the hydrophilicity of the surface of the substrate; a second liquid treatment for making the zeta potential of the surface of the substrate negative; A substrate processing method comprising:

21. a batch processing section having a plurality of batch processing units, each of which has a processing tank for storing a processing liquid, and which is configured to immerse a plurality of substrates in the processing liquid stored in the processing tank and perform liquid processing on the plurality of substrates at once; a single wafer processing section including a single wafer processing unit that processes the plurality of substrates processed by the batch processing section one by one; a standby unit having an immersion tank for storing an immersion liquid, and for allowing the plurality of substrates processed by the batch processing unit to wait in a state immersed in the immersion liquid; a transfer system that transfers the plurality of substrates from the standby unit to the single wafer processing unit, the transfer system including a first substrate transfer unit that removes the plurality of substrates immersed in the immersion liquid in the immersion tank one by one from the immersion liquid; A substrate processing method performed using a substrate processing apparatus comprising: In the waiting section, the substrate is a first immersion treatment in which the substrate is immersed in water as the immersion liquid, the dissolved oxygen concentration of which is controlled to be equal to or less than a predetermined value; or The substrate is immersed in hydrogen water or CO ２ a second immersion treatment in water; A substrate processing method comprising:

22. In the standby section, both the first liquid process and the second liquid process are performed, the first liquid treatment is performed by immersing the plurality of substrates in a first treatment liquid that is stored in the immersion tank and that can hydrophilize the surfaces of the substrates or improve or maintain the hydrophilicity of the surfaces of the substrates; 21. The substrate processing method of claim 20, wherein the second liquid processing is performed by ejecting a second processing liquid capable of making the zeta potential of the surface of the substrate negative from a processing liquid nozzle provided in the waiting section toward the substrate while the substrate is being removed from the immersion liquid by the first substrate transport unit or immediately after being removed.

23. The first liquid treatment is performed in the standby section, 21. The substrate processing method of claim 20, wherein the first liquid processing is performed by immersing the plurality of substrates in a first processing liquid stored in the immersion tank, the first processing liquid being capable of hydrophilizing the surfaces of the substrates or improving or maintaining the hydrophilicity of the surfaces of the substrates.

24. The second liquid treatment is performed in the standby section, 21. The substrate processing method according to claim 20, wherein the second liquid processing is performed by immersing the plurality of substrates in a second processing liquid stored in the immersion tank, the second processing liquid being capable of making the zeta potential of the surfaces of the substrates negative.

25. The second liquid treatment is performed in the standby section, the immersion tank stores pure water as the immersion liquid, 21. The substrate processing method of claim 20, wherein the second liquid processing is performed by supplying a second processing liquid capable of making the zeta potential of the surface of the substrate negative to the substrate from a processing liquid nozzle provided in the waiting section while the substrate is being removed from the immersion liquid by the first substrate transport unit or immediately after being removed.

26. The first immersion process is performed in the standby section, 22. The substrate processing method according to claim 21, wherein 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 100 ppb or less.

27. In order to reduce the dissolved oxygen concentration of the pure water stored in the immersion tank to 100 ppb or less, removing dissolved oxygen from the pure water by bubbling with nitrogen gas, hydrogen gas, or carbon dioxide gas; and A low-dissolved oxygen concentration pure water, which is pure water having a dissolved oxygen concentration of less than 100 ppb, is supplied to the pure water stored in the immersion tank, and a portion of the pure water stored in the immersion tank is replaced with the supplied low-dissolved oxygen concentration pure water. The method of claim 26 , further comprising the steps of:

28. The second immersion process is performed in the standby section, The second immersion treatment is carried out by immersing CO 2 having an electrical conductivity of less than 1 MΩ cm stored in the immersion tank. ２ 22. The substrate processing method according to claim 21, wherein the method is carried out by immersing the plurality of substrates in water or hydrogen water having a dissolved hydrogen concentration of more than 1 ppm.

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