SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

Abstract

To provide a substrate processing apparatus and a substrate processing method capable of preventing troubles associated with drying while processing a plurality of substrates in a short time.SOLUTION: A substrate processing apparatus 10 includes a batch type cleaning unit 13 that cleans a plurality of substrates WF at the same time, a holding unit 500 that holds the plurality of substrates WF cleaned by the batch type cleaning unit 13, and a single wafer transport unit 15 and a drying unit 16 that take out the substrates WF one by one from the holding unit 500 and dry them. The holding unit 500 includes a vapor pressure adjusting device 522 that keeps the surface S1 of each held substrate WF wet with a rinsing liquid 221.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a substrate processing apparatus and a substrate processing method. [Background technology]

[0002] In the manufacturing process of a semiconductor device such as a NAND flash memory, a substrate is cleaned and dried by a substrate processing apparatus. The substrate to be cleaned is, for example, a silicon wafer having a surface that has been subjected to a process such as film formation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-259222 [Patent Document 2] JP 2010-182817 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to the embodiments of the present invention, a substrate processing apparatus and a substrate processing method are provided that are capable of processing a plurality of substrates in a short time while preventing problems associated with drying. [Means for solving the problem]

[0005] The substrate processing apparatus according to the embodiment includes a batch cleaning unit that simultaneously cleans a plurality of substrates, a holder that holds the plurality of substrates cleaned in the batch cleaning unit, and a single-wafer drying unit that removes the substrates one by one from the holder and dries them. The holder has a maintenance mechanism that maintains a first surface of each of the substrates held in a state wetted with a liquid. [Brief description of the drawings]

[0006] [Figure 1]FIG. 1 is a schematic top view of the overall configuration of a substrate processing apparatus according to this embodiment. [Diagram 2] FIG. 2 is a diagram for explaining an example of a problem caused by dryness. [Diagram 3] FIG. 3 is a diagram for explaining an example of a problem caused by dryness. [Figure 4] FIG. 4 is a diagram showing the configuration of a batch cleaning unit. [Diagram 5] FIG. 5 is a diagram showing the configuration of a lifter which is a part of the batch cleaning unit. [Figure 6] FIG. 6 is a diagram showing the configuration of a transport mechanism that transports a substrate. [Figure 7] FIG. 7 is a diagram showing the configuration of a transport mechanism that transports a substrate. [Figure 8] FIG. 8 is a diagram showing the configuration of a transport mechanism that transports a substrate. [Figure 9] FIG. 9 is a diagram showing the configuration of a transport mechanism that transports a substrate. [Figure 10] FIG. 10 is a diagram showing the configuration of a transport mechanism that transports a substrate. [Figure 11] FIG. 11 is a diagram showing the configuration of a transport mechanism that transports a substrate. [Figure 12] FIG. 12 is a diagram showing the configuration of a holding section which is a part of the delivery unit. [Figure 13] FIG. 13 is a diagram showing the configuration of a holding section which is a part of the delivery unit. [Figure 14] FIG. 14 is a diagram showing the configuration of a single wafer transfer unit. [Figure 15] FIG. 15 is a diagram showing the configuration of a supercritical device which is a part of the drying unit. [Figure 16] FIG. 16 is a flowchart showing a flow of processing executed by the control device of the holding unit. [Figure 17] FIG. 17 is a diagram showing the configuration of a steam pressure regulating device. [Figure 18] FIG. 18 is a diagram showing another example of the configuration of the steam pressure regulating device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0008] The configuration of a substrate processing apparatus 10 according to this embodiment will be described. The substrate processing apparatus 10 is used in the manufacturing process of a semiconductor memory device, for example, a NAND flash memory, and is configured as an apparatus for cleaning and drying a substrate WF. The substrate WF is, for example, a disk-shaped silicon wafer, one of whose surfaces is previously formed with a pattern as shown in FIG. 2. The substrate to be processed by the substrate processing apparatus 10 may be a substrate other than a silicon wafer. The substrate processing apparatus 10 may also be used in the manufacturing process of a device other than a semiconductor memory device.

[0009] As shown in FIG. 1, the substrate processing apparatus 10 includes a load port 11, a batch-type transfer unit 12, a batch-type cleaning unit 13, a transfer unit 14, a single-wafer transfer unit 15, a drying unit 16, and a load port 17.

[0010] The load port 11 is a portion that receives from the outside the substrate WF to be processed by the substrate processing apparatus 10. The substrate WF is placed on the load port 11, for example, in a state in which a plurality of substrates WF are accommodated in an airtight container called a FOUP.

[0011] The batch-type transfer unit 12 is a device for taking out a plurality of substrates WF from a FOUP installed on the load port 11 and transferring them to a batch-type cleaning unit 13, which will be described next. The substrates WF are lined up in a direction perpendicular to their main surfaces and transferred to the batch-type cleaning unit 13 while being held by the batch-type transfer unit 12 and spaced apart from each other.

[0012] The batch cleaning unit 13 is an apparatus for cleaning the substrates WF. In the batch cleaning unit 13, a plurality of substrates WF are simultaneously immersed in a chemical solution containing, for example, phosphoric acid, thereby performing a cleaning process. Also, in the batch cleaning unit 13, a plurality of substrates WF are simultaneously immersed in a rinse liquid such as pure water, thereby performing a rinse process. The batch cleaning unit 13 corresponds to the "batch cleaning section" in this embodiment. A specific configuration of the batch cleaning unit 13 will be described later.

[0013] The transfer unit 14 is a device for transferring the substrates WF that have been cleaned in the batch cleaning unit 13 to the subsequent single-wafer transfer unit 15. In the transfer unit 14, the multiple substrates WF that have been cleaned are temporarily held by a holder 500 (see FIG. 12) described below. This enables the single-wafer transfer unit 15 to take out the substrates WF one by one from the holder 500. The specific configuration of the transfer unit 14 will be described later.

[0014] The single-wafer transfer unit 15 is a device for taking out the substrates WF one by one from the holder 500 of the transfer unit 14 and transporting them to the drying unit 16. The drying unit 16 is a device for receiving the substrates WF transported by the single-wafer transfer unit 15 and drying the substrates WF. The drying unit 16 dries the substrates WF one by one by a method called "supercritical drying". A plurality of drying units 16 are provided around the single-wafer transfer unit 15. In the example of FIG. 1, four drying units 16 are provided, but the number of drying units 16 may be different. The single-wafer transfer unit 15 and the plurality of drying units 16 as a whole take out the substrates WF one by one from the holder 500 and dry them, and correspond to the "single-wafer drying section" in this embodiment. The specific configurations of the single-wafer transfer unit 15 and the drying unit 16 will be described later.

[0015] After being dried by the drying unit 16, the substrate WF is removed from the drying unit 16 by the single-wafer transfer unit 15 and transferred to the load port 17. The load port 17 is a portion for transferring a plurality of substrates WF after being processed in the substrate processing apparatus 10 to the outside. An empty FOUP is installed in the load port 17 in advance. The dried substrate WF is transferred into the FOUP and accommodated therein by the single-wafer transfer unit 15. The substrate WF is removed from the load port 17 while still accommodated in the FOUP, and transferred to an apparatus for a subsequent process.

[0016] As described above, the substrate processing apparatus 10 according to this embodiment is configured to clean the substrate WF in a batch manner, while drying the substrate WF in a single-wafer manner. From the viewpoint of processing a plurality of substrates WF in a short period of time, it may seem better to perform both cleaning and drying of the substrate WF in a batch manner. However, if the substrate WF is dried in a batch manner, problems associated with drying may occur.

[0017] The reason for this will be explained. Fig. 2 shows a schematic diagram of an example of a cross section of a substrate WF to be processed. The substrate WF in Fig. 2 is in a state in the middle of being manufactured into a semiconductor memory device. A plurality of insulating layers 810 and memory pillars 700 penetrating these insulating layers 810 are formed on the surface of the substrate WF.

[0018] The memory pillar 700 is a columnar body having a substantially cylindrical shape and extends in the vertical direction. The memory pillar 700 has a semiconductor pillar 710 and a laminated film 720. The semiconductor pillar 710 is formed of, for example, polysilicon, and is provided in the central portion of the memory pillar 700. An insulator may be provided inside the semiconductor pillar 710.

[0019] The laminated film 720 covers the entire side surface of the semiconductor pillar 710 and is formed by laminating a plurality of films. These multiple films include a block insulating film, a charge trap film, a tunnel film, and the like (not shown).

[0020] The insulating layer 810 is a film made of an insulator such as silicon oxide, and a plurality of insulating layers 810 are provided so as to be aligned vertically at intervals. Gaps 811 formed between adjacent insulating layers 810 are portions into which a conductor such as tungsten will be embedded in a later process. This conductor is used as a word line for applying a voltage to the gate of the memory cell. Each of the portions of the memory pillar 700 that intersect with the conductor functions as a memory cell.

[0021] The gap 811 is formed by laminating insulating layers 810 and sacrificial layers alternately in advance, forming slits ST in the resulting laminate as shown in Fig. 2, and removing the sacrificial layers by wet etching through the slits ST. Silicon nitride, for example, is used as the sacrificial layer.

[0022] In this embodiment, the substrate WF in the state shown in FIG. 2 after the sacrificial layer has been removed by wet etching as described above and before the conductor is embedded in the formed gap 811 is treated by the substrate processing apparatus 10. The substrate WR in a state different from that shown in FIG. 2 may be treated by the substrate processing apparatus 10. Of the entire surface of the substrate WF including the insulating layer 810, etc., the surface on which the insulating layer 810, etc. is formed is hereinafter also referred to as "surface S1." Surface S1 corresponds to the "first surface" in this embodiment.

[0023] Fig. 3(A) shows an enlarged view of a part of Fig. 2. As described above, when processing is performed by the substrate processing apparatus 10, the substrate WF has a plurality of insulating layers 810 arranged side by side with gaps 811 therebetween. Therefore, immediately after the substrate WF is cleaned by the batch cleaning unit 13, the liquid used for cleaning (e.g., pure water as a rinsing liquid) has entered the gaps 811.

[0024] If the liquid in the gaps 811 gradually decreases from this state, for example by evaporation, a force that reduces some of the gaps 811 may be applied to the insulating layer 810 due to the surface tension of the liquid. As a result, as shown in FIG. 3B, a part of the insulating layer 810 forming the pattern may deform and collapse, possibly coming into contact with another adjacent insulating layer 810. Such collapse of the pattern is undesirable because it interferes with the normal operation of the semiconductor memory device. If multiple substrates WF are dried at once, i.e., if a batch drying method is used, the rate at which the liquid decreases on each substrate WF is slower than when a single substrate drying method is used, and therefore the above-mentioned collapse of the pattern is more likely to occur.

[0025] 2, the width of the slit ST tends to become gradually smaller as it approaches the lower substrate WF. Therefore, the length of the gap 811 in the left-right direction becomes longer as it approaches the lower substrate WF, and the collapse of the pattern as shown in FIG. 3(B) becomes more likely to occur compared to the upper side.

[0026] If the number of layers of the insulating layer 810 increases, the length of the gap 811 in the left-right direction at a position close to the substrate WF becomes longer, making the pattern collapse more likely to occur. For this reason, if the patterns formed on the substrate RF become finer and more highly laminated, it is expected that it will become more difficult to dry the substrate RF in a batch manner.

[0027] Therefore, in the substrate processing apparatus 10 of this embodiment, cleaning of the substrates WF is performed in a batch manner, making it possible to process multiple substrates WF in a short period of time, while drying of the substrates WF is performed in a single-wafer manner, thereby preventing the above-mentioned problems associated with drying.

[0028] The specific configuration of each part of the substrate processing apparatus 10 will be described. First, the configuration of the batch cleaning unit 13 will be described. The batch cleaning unit 13 has a cleaning tank 210 and a rinsing tank 220 shown in Fig. 4. The cleaning tank 210 stores a chemical liquid 211 containing, for example, phosphoric acid as a main component. The rinsing tank 220 stores a rinsing liquid 221 such as ultrapure water.

[0029] The plurality of substrates WF transported to the batch cleaning unit 13 by the batch-type transport unit 12 are first transported, while being held by the lifter 230, into the cleaning tank 210 and immersed in the chemical liquid 211.

[0030] 5, the lifter 230 has a plate-like body 231 and a rod-like body 240. The plate-like body 231 is a generally flat member, and is provided with its normal direction facing horizontally. The plate-like body 231 moves vertically and horizontally by the force of a driving device (not shown).

[0031] The rod-like bodies 240 are rod-like members provided so as to extend along the normal direction of the plate-like body 231. A total of three rod-like bodies 240 are provided, and one end of each of the rod-like bodies 240 is joined to the plate-like body 231. The other end of each of the rod-like bodies 240 is joined to the reinforcing plate 233. The rod-like bodies 240 are members for supporting each of the substrates WF from below. Each of the rod-like bodies 240 has a plurality of grooves 241 formed in the longitudinal direction thereof. Each of the substrates WF is held in a state where it is inserted into the grooves 241.

[0032] 4, the substrate WF is supported from below by three rod-shaped bodies 240 in a state in which it stands parallel to the plate-shaped body 231. The substrates WF are supported in a state in which a plurality of substrates WF are lined up in the depth direction of the paper surface in FIG.

[0033] The substrates WF are immersed in the chemical solution 211 while being supported by the lifter 230, and are simultaneously cleaned. Specifically, the silicon nitride film remaining on the substrates WF is removed by phosphoric acid. Note that cleaning of the substrates WF in the cleaning tank 210 may be performed using other chemical solutions for other purposes.

[0034] When cleaning of the substrates WF in the cleaning tank 210 is completed, the lifter 230 moves upward and pulls out the multiple substrates WF from the chemical liquid 211. Thereafter, the lifter 230 moves to the right side in Fig. 4 and descends after reaching directly above the rinsing tank 220. As a result, the multiple substrates WF are immersed in the rinsing liquid 221 in the rinsing tank 220 while still being supported by the lifter 230.

[0035] By immersing the substrate WF in the rinsing liquid 221, the chemical liquid 211 adhering to the surface S1 and the like of the substrate WF is replaced with the rinsing liquid 221. Note that a liquid other than ultrapure water may be used as the rinsing liquid 221. Furthermore, the substrate WF after being pulled out of the chemical liquid 211 may be immersed in an alkaline cleaning tank and cleaned before being immersed in the rinsing liquid 221.

[0036] When the rinsing process of the substrates WF in the rinsing tank 220 is completed, the lifter 230 moves upward and pulls out the substrates WF from the rinsing liquid 221. This completes the cleaning of the substrates WF by the batch cleaning unit 13. At this time, the entire surface of each substrate WF, including the surface S1, is wet with the rinsing liquid 221.

[0037] Next, the configuration of the delivery unit 14 will be described. The delivery unit 14 is provided with a plurality of transport mechanisms for transporting the substrate WF after cleaning. A transport member 250 shown in Fig. 6 is one of the transport mechanisms provided in the delivery unit 14, and is a member for removing the substrate WF from the lifter 230 and moving it. Note that, although the transport mechanism is a part of the delivery unit 14 as described above, a part of it can also enter inside the batch cleaning unit 13 and operate.

[0038] The transport members 250 are substantially flat plate-shaped members, and two transport members 250 are provided in total. As shown in FIG. 6, the pair of transport members 250 sandwich the multiple substrates WF supported by the lifter 230 from both the left and right sides. As shown in FIG. 7, a multiple number of grooves 251 extending in the vertical direction are formed on the surface of each transport member 250 facing the substrate WF. The direction in which the multiple grooves 251 are lined up is the same as the direction in which the substrates WF are lined up on the lifter 230. In addition, the distance between adjacent grooves 251 is the same as the distance between adjacent substrates WF on the lifter 230.

[0039] As shown in Fig. 6, the pair of transport members 250 are inclined so that their lower ends approach each other, and sandwich the multiple substrates WF from both the left and right sides. A portion of each substrate WF enters a groove 251 of the transport member 250, and is supported from below by the transport member 250. Thereafter, the pair of transport members 250 move in the state shown in Fig. 6, and the substrates WF are removed from the lifter 230. Thereafter, the multiple substrates WF are transferred from the transport members 250 to the rotation mechanism 300 of Fig. 8. The rotation mechanism 300, together with the transport members 250, is part of the transport mechanism provided in the delivery unit 14.

[0040] As shown in FIG. 8, the rotation mechanism 300 has one first holding member 310 and two second holding members 320. These are all plate-shaped members and support each of the multiple substrates WF from three locations. The first holding member 310 has multiple grooves 311 into which the substrate WF fits. The second holding member 320 also has multiple grooves 321 into which the substrate WF fits. In the state of FIG. 8, that is, immediately after the substrate WF is transferred from the transport member 250 to the rotation mechanism 300, the first holding member 310 supports the substrate WF from below, and each of the pair of second holding members 320 supports the substrate WF by sandwiching it from the side. Note that the transport member 250 shown in FIG. 6 may operate as the second holding member 320 as it is.

[0041] The rotation mechanism 300 is configured so that the first holding member 310 and the second holding member 320 can be rotated 90 degrees in the direction of the arrow AR1 around the rotation axis AX1 shown in Fig. 8. Fig. 9 shows the state after such rotation. In the state of Fig. 9, the multiple substrates WF are lined up at equal intervals in the vertical direction with the normal direction of their main surfaces aligned along the vertical direction. At this time, the surface S1 of each substrate WF is the upper surface side.

[0042] Since the substrate WF was immersed in the rinse liquid 221 before reaching the state shown in FIG. 9, the entire surface including the surface S1 is wet with the rinse liquid 221. In the state shown in FIG. 9, the upper surface S1 is horizontal, so that the rinse liquid 221 on the surface S1 remains on the surface S1 without falling due to gravity. In this manner, in this embodiment, each of the substrates WF lifted out of the rinse liquid 221 is rotated in a short time to make the surface S1 horizontal, thereby maintaining the entire surface S1 wet with the rinse liquid 221. This prevents the rinse liquid 221 from drying on a part of the surface S1, causing the pattern to collapse as shown in FIG. 3(B).

[0043] Next, the multiple substrates WF are taken out from the rotation mechanism 300 by the transport member 400 shown in Figures 10 and 11. The transport member 400, together with the transport member 250 and the rotation mechanism 300, is a part of the transport mechanism included in the delivery unit 14. Figure 10 shows the transport member 400 holding the multiple substrates WF as viewed in the horizontal direction. Figure 11 shows the transport member 400 holding the multiple substrates WF as viewed from above in the vertical direction.

[0044] The transport member 400 has a vertical shaft 410 and a horizontal arm 420. The vertical shaft 410 is a rod-shaped member. The vertical shaft 410 can be moved by a drive mechanism (not shown) while keeping its longitudinal direction aligned along the vertical direction. The horizontal arms 420 are plate-shaped members connected to the vertical shaft 410, and a plurality of horizontal arms 420 are provided so as to be aligned along the longitudinal direction of the vertical shaft 410. The distance between adjacent horizontal arms 420 is the same as the distance between adjacent substrates WF when held by the rotation mechanism 300.

[0045] 10, the multiple substrates WF removed from the rotation mechanism 300 by the transport member 400 are in a state in which the surfaces S1 of the substrates WF face upward, similar to when they are held by the rotation mechanism 300. In addition, the entire surfaces S1 of the substrates WF are wet with the rinsing liquid 221. Each substrate WF is transported by the transport member 400 to the inside of the holder 500 while maintaining the entire surfaces S1 wet with the rinsing liquid 221.

[0046] The holding unit 500 is a substantially rectangular parallelepiped container provided as a part of the delivery unit 14. The configuration of the holding unit 500 is shown in Fig. 12. The holding unit 500 includes a top plate 511, a bottom plate 512, a side plate 513, an entrance shutter 514, and an exit shutter 515.

[0047] The top plate 511 is a substantially rectangular plate-like member arranged along a horizontal plane, and is disposed in an upper portion of the holding part 500. The bottom plate 512 is a substantially rectangular plate-like member arranged along a horizontal plane, and is disposed in a lower portion of the holding part 500. The side plates 513 are substantially rectangular plate-like members arranged so as to connect between the top plate 511 and the bottom plate 512, and are disposed on both the back side and the front side of the paper in FIG.

[0048] The top plate 511, the bottom plate 512, and the pair of side plates 513 are arranged as described above to form a cylindrical shape as a whole, and openings are formed on both the left and right sides of FIG. 12. Of these, the opening formed on the left side of FIG. 12 is an entrance 501 for carrying the substrate WF into the inside of the holding part 500. The opening formed on the right side of FIG. 12 is an exit 502 for carrying the substrate WF out from the inside of the holding part 500. Normally, the entrance 501 is blocked by an entrance shutter 514, and the exit 502 is blocked by an exit shutter 515. The entrance shutter 514 and the exit shutter 515 are both substantially rectangular plate-like members, and can slide up and down by a drive mechanism (not shown). The operations of the entrance shutter 514 and the exit shutter 515 are individually controlled by a control device 523 described later.

[0049] A plurality of support protrusions 516 are provided on the inner surface of each of the opposing side plates 513 so as to be aligned in the vertical direction. As shown in Fig. 13, the support protrusions 516 are formed so as to protrude inward from each of the side plates 513. The support protrusions 516 support the substrate WF from below. The distance between adjacent support protrusions 516 in the vertical direction is the same as the distance between adjacent horizontal arms 420 in the same direction.

[0050] A plurality of substrates WF are simultaneously carried into the space SP1 formed inside the holding part 500 by the transport member 400. At this time, the entrance shutter 514 slides upward in advance to open the entrance 501. Next, the transport member 400 holding the plurality of substrates WF is inserted into the space SP from the entrance 501, as shown in FIG. 10, and each substrate WF is placed on the support protrusion 516. Thereafter, the transport member 400 moves to the outside, and the entrance 501 is closed by the entrance shutter 514. The transport member 400 may carry in the substrates WF all at once, or may carry out multiple times.

[0051] When the substrate WF is removed from the holder 500 by the single-wafer transfer unit 15, the exit shutter 515 slides upward in advance to open the exit 502. When removal of the substrate WF is completed, the exit shutter 515 slides downward to close the exit 502. The substrates WF are removed one by one, and each time a substrate WF is removed, the above-described opening and closing operation of the exit shutter 515 is performed.

[0052] The configuration of the single-wafer transfer unit 15 will be described. The single-wafer transfer unit 15 is provided with a transfer member 401 shown in FIG. 14. The transfer member 401 has a vertical shaft 411 and a horizontal arm 421. The vertical shaft 411 is a rod-shaped member. The vertical shaft 411 can be moved by a drive mechanism (not shown) while keeping its longitudinal direction aligned vertically. The horizontal arm 421 is a plate-shaped member connected to the vertical shaft 410, and only one horizontal arm 421 is provided in the transfer member 401. The shape of the horizontal arm 421 is the same as the shape of the horizontal arm 420 shown in FIG. 11.

[0053] When the substrate WF is removed from the holder 500 by the transport member 401 of the single-wafer transport unit 15, as described above, the exit shutter 515 of the holder 500 slides upward to open the exit 502. Next, the transport member 401 is inserted into the space SP from the exit 502, and one substrate WF is lifted up from the support protrusion 516 by the horizontal arm 421. After the transport member 401 moves out of the holder 500 while holding the substrate WF as shown in FIG. 14, the exit 502 is closed by the exit shutter 515.

[0054] The configuration of the drying unit 16 will be described. As described above, the drying unit 16 dries the substrates WF one by one by a method called "supercritical drying." In supercritical drying, the rinsing liquid 221 covering the surface S1 of the substrate WF is replaced in advance with a water-soluble organic solvent such as IPA, and the water-soluble organic solvent is then heated to a supercritical state. The rinsing liquid 221 is replaced with IPA by immersing the substrate WF in IPA stored in a tank (not shown), but another known method may be used.

[0055] Thereafter, the substrate WF, with the entire surface S1 still wet with IPA, is carried into the chamber 610 of the supercritical apparatus 600 by the carrying member 401. The supercritical apparatus 600 is an apparatus for subjecting the substrate WF to a supercritical drying process by bringing the IPA on the surface S1 of the substrate WF into a supercritical state.

[0056] The supercritical apparatus 600 includes a chamber 610 , a stage 620 , a heater HT, and a pipe 630 .

[0057] The chamber 610 is a container for accommodating the substrate WF to be dried. A space SP2 is formed inside the chamber 610. When supercritical drying is performed, the inside of the space SP2 becomes high pressure, so the chamber 610 is a high-pressure container made of, for example, SUS or the like.

[0058] The stage 620 is a platform on which the substrate WF is placed. A recess 621 is formed on the upper surface of the stage 620. The substrate WF is placed from above on a ring-shaped portion of the stage 620 that is formed around the recess 621. As shown in Fig. 15, the substrate WF is placed on the stage 620 with the surface S1 facing upward. Note that the reference symbol "LQ" in Fig. 15 denotes the liquid IPA that covers the entire surface S1.

[0059] The heater HT is an electric heater for heating the chamber 610. When electricity is applied to the heater HT, the heater HT generates heat, and the temperature of the chamber 610 and its interior increases. The heater HT may be disposed outside the chamber 610 or may be embedded in the wall of the chamber 610.

[0060] The pipe 630 is a pipe for discharging gas from the inside of the chamber 610 to the outside. A control valve 631 is provided midway along the pipe 630. When supercritical drying is performed, the opening of the control valve 631 is adjusted by a control device (not shown), thereby adjusting the pressure in the space SP2.

[0061] When the substrate WF to be dried is placed on the upper surface of the stage 620, a shutter (not shown) is closed to seal the space SP2. The chamber 610 is then heated by the heater HT. The IPA is heated and partially vaporized, causing the pressure in the space SP2 to increase. When the pressure reaches the critical pressure of the IPA and the temperature of the IPA rises to or above the critical temperature, the space SP2 becomes filled with IPA in a supercritical state. At this time, the surface S1 of the substrate WF becomes covered with IPA in a supercritical state.

[0062] Thereafter, the control valve 631 is opened, and the IPA in the supercritical state is discharged from the space SP2. Since the IPA is removed from the surface S1 of the substrate WF while remaining in the supercritical state without returning to a liquid state, no surface tension acts on the insulating layer 810, and the pattern does not collapse as shown in FIG.

[0063] The supercritical apparatus 600 may be configured to supply the supercritical fluid from the pipe 630 to fill the space SP2, and the specific configuration is not limited to that described above. The supercritical fluid is not limited to IPA. For example, carbon dioxide, water, hydrocarbon, perfluorocarbon, or the like that has been heated to a high temperature and high pressure and brought to a supercritical state may be used as the supercritical fluid.

[0064] When the supercritical drying is completed, the substrate WF is taken out of the supercritical apparatus 600 by the transfer member 401 of the single-wafer transfer unit 15 and transferred to the load port 17.

[0065] Incidentally, as described above, the substrates WF are taken out one by one from the holder 500 of the delivery unit 14 and transported to the drying unit 16. In this configuration, after cleaning of the substrates WF by the batch cleaning unit 13 is completed, some of the multiple substrates WF are made to wait for a long time in the holder 500 before being dried. For this reason, in some of the substrates WF, the rinsing liquid 221 dries over time, which may cause the pattern to collapse due to surface tension.

[0066] Therefore, in the substrate processing apparatus 10 according to this embodiment, the holding part 500 is provided with a vapor pressure adjusting device 522 or the like, thereby preventing the substrate WF from drying out in the holding part 500.

[0067] The configuration for this purpose will be described below. As shown in Fig. 12, the holding unit 500 is provided with a vapor pressure sensor 521, a vapor pressure adjusting device 522, and a control device 523.

[0068] The vapor pressure sensor 521 is a sensor for measuring the vapor pressure in the space SP1. The "vapor pressure" measured by the vapor pressure sensor 521 refers to the partial pressure of the vapor of the liquid (the rinsing liquid 221 in this embodiment) covering the surface S1 of the substrate WF. When the rinsing liquid 221 is pure water as in this embodiment, for example, a humidity sensor can be used as the vapor pressure sensor 521. The value of the vapor pressure measured by the vapor pressure sensor 521 is transmitted to a control device 523 described later.

[0069] The vapor pressure adjusting device 522 is a device for adjusting the vapor pressure in the space SP1. The "vapor pressure" adjusted by the vapor pressure adjusting device 522 is the same as the "vapor pressure" measured by the vapor pressure sensor 521. The vapor pressure adjusting device 522 can increase the vapor pressure in the space SP1 by spraying the same liquid (the rinsing liquid 221 in this embodiment) as the liquid covering the surface S1 of the substrate WF, for example in the form of mist. The operation of the vapor pressure adjusting device 522 is controlled by the control device 523.

[0070] The control device 523 is a device, such as a microcomputer, for controlling the overall operation of the holding unit 500. As described above, the control device 523 controls the operation of each of the entrance shutter 514 and the exit shutter 515. In addition, the control device 523 controls the operation of the vapor pressure adjusting device 522 based on the value of the vapor pressure measured by the vapor pressure sensor 521.

[0071] The flow of processing executed by the control device 523 will be described with reference to Fig. 16. A series of processing shown in the flowchart of Fig. 16 is repeatedly executed every time a predetermined control period elapses during the period in which the substrate WF is accommodated inside the holder 500.

[0072] In the first step S01 of this process, a process of acquiring the value of the vapor pressure measured by the vapor pressure sensor 521 is performed. In step S02 following step S01, it is determined whether the value of the vapor pressure acquired in step S01 is equal to or lower than a set value. This "set value" is set to a value slightly higher than a target pressure that is preset as a target value for the vapor pressure in space SP1. If the acquired vapor pressure exceeds the set value, the series of processes shown in FIG. 16 is terminated. If the acquired vapor pressure is equal to or lower than the set value, the process proceeds to step S03.

[0073] In step S03, the steam pressure adjusting device 522 is operated to perform a process of increasing the steam pressure in the space SP1. As a result, the steam pressure in the space SP1 increases to the above-mentioned set value or higher.

[0074] By repeatedly performing the above-mentioned process, the vapor pressure of the rinsing liquid 221 around the substrate WF is always kept at or above the target pressure. In this embodiment, the above-mentioned target pressure is set in advance as the minimum vapor pressure for keeping the entire surface S1 wet with the rinsing liquid 221 during the period in which the substrate WF is held inside the holding part 500. Therefore, when the vapor pressure of the rinsing liquid 221 around the substrate WF is kept at or above the target pressure as described above, the rinsing liquid 221 does not dry out on a part of the surface S1 during the period until the substrate WF is removed from the holding part 500.

[0075] The vapor pressure sensor 521, the vapor pressure adjusting device 522, and the control device 523 maintain the vapor pressure of the rinsing liquid 221 around the substrate WF at a target pressure or higher, thereby maintaining a state in which the surface S1 of the substrate WF is wet with the rinsing liquid 221. The vapor pressure sensor 521, the vapor pressure adjusting device 522, and the control device 523 correspond to the "maintenance mechanism" in this embodiment. The maintenance mechanism can be said to be a mechanism that supplies a liquid or gas having the same composition as the liquid covering the surface S1 to the surface S1 of each substrate WF held by the holding part 500.

[0076] Various types of devices can be used as the steam pressure adjusting device 522, which is a maintenance mechanism. As one example, the configuration of the steam pressure adjusting device 522 in this embodiment is shown in Fig. 17. As shown in the figure, the steam pressure adjusting device 522 includes a tank 531, a heater 532, a pressurizing pipe 533, and a supply pipe 534.

[0077] The tank 531 is a sealed container. The rinsing liquid 221 is stored in a liquid state in a space SP11 inside the tank 531.

[0078] The heater 532 is an electric heater for generating steam of the rinsing liquid 221 in the space SP11 by heating the rinsing liquid 221 in the tank 531. The operation of the heater 532 is controlled by the control device 523.

[0079] The pressurizing pipe 533 is a pipe for introducing a gas for pressure delivery (e.g., air) into the space SP11 by a pump (not shown) to send the air generated in the space SP11 to a supply pipe 534 described below. An end of the pressurizing pipe 533 opens above the liquid level LS of the rinsing liquid 221. Any gas can be used as the gas for pressure delivery sent from the pressurizing pipe 533 as long as the gas does not react with the rinsing liquid 221 or the film on the substrate WF. The operation of the vapor pump for sending the air for pressure delivery is controlled by the control device 523.

[0080] The supply pipe 534 is a pipe for guiding the vapor of the rinsing liquid 221 generated in the space SP11 to the space SP2. A valve 535 is provided in the middle of the supply pipe 534, and the operation of the valve 535 is controlled by the control device 523. An upstream end of the supply pipe 534 opens above the liquid level LS of the rinsing liquid 221.

[0081] With heater 532 in an on state, control device 523 sends gas for pressure delivery from pressurizing pipe 533 and simultaneously opens valve 535. This causes rinsing liquid 221 in a mist or gaseous state to be supplied to space SP2, and prevents the rinsing liquid 221 from drying on surface S1 as described above.

[0082] An ultrasonic generator may be used instead of the heater 532. In this case, the control device 523 can generate a mist of the rinsing liquid 221 in the space SP11 by operating the ultrasonic generator. Thereafter, by feeding gas for pressure delivery from the pressurizing tube 533 and opening the valve 535, the mist-like rinsing liquid 221 can be supplied to the space SP2.

[0083] Note that a mechanism different from the above may be used as the vapor pressure adjusting device 522, which is the maintaining mechanism. For example, a mechanism that periodically supplies the rinsing liquid 221 in liquid form to the surface S1 of the substrate WF may be provided as the vapor pressure adjusting device 522. Even when such a vapor pressure adjusting device 522 is employed, the surface S1 of each substrate WF held by the holding unit 500 can be maintained in a state where it is wet with the rinsing liquid 221.

[0084] As a configuration of such a vapor pressure adjusting device 522, the configuration shown in Fig. 18 can be adopted. In the example shown in Fig. 18, an upstream end of a supply pipe 534 opens below the liquid level LS of the rinsing liquid 221. In addition, a spray nozzle 536 is provided at a downstream end of the supply pipe 534. In this example, a heater 532 is not provided.

[0085] Even in such a configuration, the control device 523 opens the valve 535 at the same time as sending the gas for pressure delivery from the pressurizing pipe 533. In this example, the rinsing liquid 221 is sent as a liquid to the supply pipe 534, and is sprayed as a liquid from the spray nozzle 536 into the space SP2, and reaches the surface S1 of each substrate WF. Note that a plurality of spray nozzles 536 may be provided so that the rinsing liquid 221 can be sprayed toward a plurality of substrates WF. Also, a shower head may be provided instead of the spray nozzle 536.

[0086] The steam pressure regulator 522 shown in FIG. 17 or FIG. 18 may be entirely disposed inside the holding unit 500, or part or all of it may be disposed outside the holding unit 500.

[0087] The method of processing the substrates WF executed by the substrate processing apparatus 10 is to simultaneously clean a plurality of substrates WF in the batch cleaning unit 13, hold each of the substrates WF inside the holder 500 while maintaining the respective surfaces S1 of the plurality of cleaned substrates WF wet with the rinsing liquid 221, and remove the held substrates WF one by one from the holder 500 and dry them by the drying unit 16. In order to maintain the surface S1 wet with the rinsing liquid 221, the above-mentioned maintenance mechanism maintains the vapor pressure of the rinsing liquid 221 around the substrate WF held by the holder 500 at a target pressure or higher. By performing the cleaning and drying processes of the substrates WF in this manner, it is possible to clean a plurality of substrates WF in a short time while preventing the collapse of the pattern due to drying.

[0088] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0089] 10: substrate processing apparatus, 13: batch type cleaning unit, 15: single wafer transfer unit, 16: drying unit, 221: rinsing liquid, 500: holder, 521: vapor pressure sensor, 522: vapor pressure regulator, 523: controller, WF: substrate, S1: surface.

Claims

1. A batch cleaning unit that cleans multiple substrates simultaneously; a holder for holding the plurality of substrates cleaned in the batch cleaning unit; a single-wafer drying section that removes the substrates one by one from the holder and dries them, the holding unit has a maintaining mechanism for maintaining the first surface of each of the substrates held by the holding unit in a state wetted with a liquid; the maintaining mechanism maintains the vapor pressure of the liquid around the substrate at or above a target pressure; The target pressure is a minimum vapor pressure required to keep the first surface wet with the liquid.

2. A batch-type cleaning unit for simultaneously cleaning multiple substrates; a holder for holding the plurality of substrates cleaned in the batch cleaning unit; a single-wafer drying section that removes the substrates one by one from the holder and dries them, the holding unit has a maintaining mechanism for maintaining the first surface of each of the substrates held by the holding unit in a state wetted with a liquid; The maintaining mechanism includes a steam pressure adjusting device that adjusts the steam pressure in the space inside the holding part.

3. Multiple substrates can be cleaned at the same time. holding each of the plurality of cleaned substrates while maintaining a first surface of each of the substrates wetted with a liquid; maintaining a vapor pressure of the liquid around the held substrate at or above a target pressure, thereby maintaining the first surface in a state where it is wetted with the liquid; the target pressure is a minimum vapor pressure required to keep the first surface wetted with the liquid; The substrate processing method further comprises removing the held substrates one by one and drying them.

4. A method for simultaneously cleaning multiple substrates, holding each of the plurality of cleaned substrates while maintaining a first surface of each of the substrates wetted with a liquid; adjusting a vapor pressure of the liquid around the held substrate; The substrate processing method further comprises removing the held substrates one by one and drying them.

5. A batch cleaning unit that cleans multiple substrates simultaneously; a holder for holding the plurality of substrates cleaned in the batch cleaning unit; a single-wafer drying section that removes the substrates one by one from the holder and dries them, the holding unit has a mechanism for supplying a liquid to a first surface of each of the substrates held by the holding unit, the mechanism maintains a vapor pressure of the liquid around the substrate at or above a target pressure; The target pressure is a minimum vapor pressure required to keep the first surface wet with the liquid.

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