Substrate processing method and substrate processing apparatus

Abstract

To provide a technique capable of improving the yield of substrates.SOLUTION: A substrate processing method according to one aspect of the present disclosure includes a liquid processing step, a conveyance step, and a supercritical step. In the liquid processing step, liquid processing of a substrate is performed in a liquid processing unit, and the top surface of the substrate is wetted. In the conveyance step, the substrate, the top surface of which has been wetted, is conveyed from the liquid processing unit to a supercritical processing unit. In the supercritical step, the substrate, the top surface of which has been wetted, is treated with a supercritical liquid in the supercritical processing unit. If it has been determined that conveyance of the substrate to the supercritical processing unit is not possible, the supply of a processing liquid to the substrate is continued in the liquid processing step.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The disclosed embodiments relate to a substrate processing method and a substrate processing apparatus. [Background technology]

[0002] Conventionally, there has been known a substrate processing apparatus that forms a liquid film to prevent drying on the upper surface of a substrate such as a semiconductor wafer (hereinafter referred to as a wafer), and then performs a drying process by contacting the substrate on which the liquid film has been formed with a processing fluid in a supercritical state (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-12538 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides techniques that can improve substrate yield. [Means for solving the problem]

[0005] A substrate processing method according to an aspect of the present disclosure includes a liquid processing step, a transport step, and a supercritical step. The liquid processing step performs liquid processing on a substrate in a liquid processing unit to wet an upper surface of the substrate. The transport step transports the substrate with the wet upper surface from the liquid processing unit to a supercritical processing unit. The supercritical step treats the substrate with the wet upper surface with a supercritical fluid in the supercritical processing unit. Furthermore, the liquid processing step continues supplying a processing liquid to the substrate when it is determined that the substrate cannot be transported to the supercritical processing unit. Effect of the Invention

[0006] According to the present disclosure, the yield of substrates can be improved. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view of a substrate processing system according to an embodiment, as viewed from above. [Diagram 2] FIG. 2 is a schematic cross-sectional view of the substrate processing system according to the embodiment as viewed from the side. [Diagram 3] FIG. 3 is a diagram illustrating an example of a configuration of the liquid processing unit. [Figure 4] FIG. 4 is a schematic perspective view showing an example of the configuration of the drying unit. [Diagram 5] FIG. 5 is a flow chart showing a sequence of substrate processing steps performed in the substrate processing system according to this embodiment. [Figure 6] FIG. 6 is a flow chart showing a procedure of liquid processing executed in the substrate processing system according to this embodiment. [Figure 7] FIG. 7 is a view for explaining another example of the substrate processing performed in the substrate processing system according to the embodiment. [Figure 8] FIG. 8 is a view for explaining another example of the substrate processing performed in the substrate processing system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, with reference to the attached drawings, an embodiment of the substrate processing method and substrate processing apparatus disclosed in the present application will be described in detail. Note that the present disclosure is not limited to the following embodiment. It should be noted that the drawings are schematic, and the dimensional relationship of each element, the ratio of each element, and the like may differ from reality. Furthermore, there may be parts in which the dimensional relationship and ratio differ between the drawings.

[0009] Conventionally, there has been known a substrate processing apparatus that forms a liquid film to prevent drying on the upper surface of a substrate such as a semiconductor wafer (hereinafter referred to as a wafer), and then performs a drying process by contacting the substrate on which the liquid film has been formed with a processing fluid in a supercritical state.

[0010] However, if a malfunction occurs in the transport unit when the substrate having the liquid film formed on the upper surface is transported to the drying unit, the substrate must wait until the malfunction is repaired.

[0011] Furthermore, if the state of the liquid film on the top surface of the substrate changes during waiting, for example because the liquid film dries out, problems such as the pattern formed on the substrate collapsing may occur during the subsequent drying process, which could result in a reduction in substrate yield.

[0012] Therefore, there is a need for a technology that can overcome the above-mentioned problems and improve the yield of substrates.

[0013] <Configuration of the substrate processing system> First, the configuration of a substrate processing system 1 (an example of a substrate processing apparatus) according to an embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a schematic cross-sectional view of the substrate processing system 1 according to an embodiment as viewed from above. Fig. 2 is a schematic cross-sectional view of the substrate processing system 1 according to an embodiment as viewed from the side. In the following, to clarify the positional relationship, an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other are defined, and the positive direction of the Z-axis is defined as the vertical upward direction.

[0014] 1, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other.

[0015] The carry-in / out station 2 includes a carrier placement section 11 and a transport section 12. A plurality of carriers C, each of which horizontally accommodates a plurality of semiconductor wafers W (hereinafter also referred to as "wafers W"), are placed on the carrier placement section 11. The wafers W are an example of a substrate.

[0016] The transport section 12 is provided adjacent to the carrier placement section 11. Inside the transport section 12, a transport device 13 and a delivery section 14 are arranged.

[0017] The transfer device 13 includes a wafer holding mechanism that holds the wafer W. The transfer device 13 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the carrier C and the transfer unit 14 using the wafer holding mechanism.

[0018] The processing station 3 is provided adjacent to the transport section 12. The processing station 3 includes a transport block 4 and a plurality of processing blocks 5.

[0019] The transport block 4 includes a transport area 15 and a transport device 16. The transport area 15 is, for example, a rectangular parallelepiped region extending along the arrangement direction (X-axis direction) of the loading / unloading stations 2 and the processing stations 3. The transport device 16 is disposed in the transport area 15.

[0020] The transfer device 16 is an example of a transfer section, and includes a wafer holding mechanism that holds the wafer W. The transfer device 16 is capable of moving in the horizontal and vertical directions and rotating about a vertical axis, and transfers the wafer W between the delivery section 14 and the multiple processing blocks 5 using the wafer holding mechanism.

[0021] The multiple processing blocks 5 are disposed adjacent to the transfer area 15 on one side of the transfer area 15. Specifically, the multiple processing blocks 5 are disposed on one side of the transfer area 15 (the negative Y-axis direction in the figure) in a direction (Y-axis direction) perpendicular to the arrangement direction (X-axis direction) of the load / unload stations 2 and the processing stations 3.

[0022] 2, the processing blocks 5 are arranged in multiple stages along the vertical direction. In the embodiment, the processing blocks 5 are arranged in three stages, but the number of stages is not limited to three.

[0023] As described above, in the substrate processing system 1 according to the embodiment, the multiple processing blocks 5 are arranged in multiple stages on one side of the transfer block 4. The transfer of the wafer W between the processing blocks 5 arranged in each stage and the interface 14 is performed by a common transfer device 16 arranged in the transfer block 4.

[0024] Each processing block 5 includes a liquid processing unit 17 and a drying unit 18. The liquid processing unit 17 is an example of a liquid processing section, and the drying unit 18 is an example of a supercritical processing section.

[0025] Liquid processing unit 17 performs a process for cleaning the upper surface, which is the pattern formation surface, of wafer W. Furthermore, liquid processing unit 17 performs a process for forming a liquid film on the upper surface of wafer W after the chemical liquid processing. The configuration of liquid processing unit 17 will be described later.

[0026] The drying unit 18 performs a supercritical drying process on the wafer W after the liquid film formation process. Specifically, the drying unit 18 dries the wafer W by bringing the wafer W after the liquid film formation process into contact with a processing fluid in a supercritical state (hereinafter also referred to as a "supercritical fluid").

[0027] In the embodiment described below, an example in which supercritical drying processing is performed in drying unit 18 will be shown, but the processing performed in drying unit 18 is not limited to supercritical drying processing, and may be processing for modifying wafer W with a supercritical fluid, etc. The configuration of drying unit 18 will be described later.

[0028] 1 and 2, the substrate processing system 1 has a supply unit that supplies a processing fluid to the drying unit 18. Specifically, the supply unit includes a group of supply devices including a flow meter, a flow regulator, a back pressure valve, a heater, etc., and a housing that houses the group of supply devices. In the embodiment, the supply unit supplies CO2 as the processing fluid to the drying unit 18.

[0029] Liquid processing unit 17 and drying unit 18 are arranged along transport area 15 (i.e., along the X-axis direction). Of liquid processing unit 17 and drying unit 18, liquid processing unit 17 is arranged at a position close to loading / unloading station 2, and drying unit 18 is arranged at a position far from loading / unloading station 2.

[0030] Thus, each processing block 5 includes one liquid processing unit 17 and one drying unit 18. That is, the substrate processing system 1 is provided with the same number of liquid processing units 17 and drying units 18.

[0031] 1, the substrate processing system 1 includes a control device 6. The control device 6 is, for example, a computer, and includes a control unit 61 and a storage unit 62.

[0032] The control unit 61 includes a microcomputer and various circuits having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), input / output ports, etc. The CPU of the microcomputer reads and executes programs stored in the ROM to realize control of the transport devices 13, 16, the liquid processing unit 17, the drying unit 18, etc.

[0033] Such a program may be stored in a computer-readable storage medium and installed from the storage medium into the storage unit 62 of the control device 6. Examples of computer-readable storage media include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

[0034] The storage unit 62 is realized by, for example, a semiconductor memory element such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk.

[0035] <Configuration of liquid processing unit> Next, the configuration of liquid processing unit 17 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of liquid processing unit 17. Liquid processing unit 17 is configured as, for example, a single-wafer cleaning device that cleans wafers W one by one by spin cleaning.

[0036] As shown in FIG. 3, in liquid processing unit 17, wafer W is held approximately horizontally by wafer holding mechanism 25 arranged in outer chamber 23 which forms the processing space, and wafer W is rotated by rotating wafer holding mechanism 25 around a vertical axis.

[0037] Then, the liquid processing unit 17 performs a cleaning process on the upper surface of the wafer W by inserting the nozzle arm 26 into the area above the rotating wafer W and supplying chemical liquid and rinsing liquid in a predetermined order from the chemical liquid nozzle 26a provided at the tip of the nozzle arm 26.

[0038] In liquid processing unit 17, a chemical liquid supply path 25a is also formed inside wafer holding mechanism 25. The lower surface of wafer W is also cleaned by the chemical liquid and rinsing liquid supplied from chemical liquid supply path 25a.

[0039] The cleaning process, for example, first removes particles and organic contaminants using an alkaline chemical solution called SC1 liquid (a mixture of ammonia and hydrogen peroxide), then performs a rinse cleaning using deionized water (hereinafter also referred to as "DIW"), which is a rinse solution.

[0040] Next, the native oxide film is removed using an acidic chemical solution, such as diluted hydrofluoric acid (hereinafter, also referred to as "DHF"), and then rinsing is performed using DIW.

[0041] The various chemical solutions described above are received in the outer chamber 23 or the inner cup 24 disposed within the outer chamber 23, and are discharged from a drainage outlet 23a provided in the bottom of the outer chamber 23 or a drainage outlet 24a provided in the bottom of the inner cup 24. Furthermore, the atmosphere within the outer chamber 23 is exhausted from an exhaust outlet 23b provided in the bottom of the outer chamber 23.

[0042] The liquid film forming process is performed after the rinsing process in the cleaning process. Specifically, liquid processing unit 17 supplies IPA in a liquid state (hereinafter also referred to as "IPA liquid") to the upper and lower surfaces of wafer W while rotating wafer holding mechanism 25. As a result, DIW remaining on both sides of wafer W is replaced with IPA. Then, liquid processing unit 17 gently stops the rotation of wafer holding mechanism 25.

[0043] After the liquid film formation process, the wafer W, with the IPA liquid film formed on its upper surface, is transferred to the transport device 16 by a transfer mechanism (not shown) provided in the wafer holding mechanism 25, and is transported out of the liquid processing unit 17.

[0044] The liquid film formed on the wafer W prevents pattern collapse caused by evaporation (vaporization) of the liquid on the top surface of the wafer W during transportation of the wafer W from the liquid processing unit 17 to the drying unit 18 or during loading into the drying unit 18.

[0045] <Overview of the drying unit> Next, the configuration of the drying unit 18 will be described with reference to Fig. 4. Fig. 4 is a schematic perspective view showing an example of the configuration of the drying unit 18.

[0046] The drying unit 18 has a main body 31, a holding plate 32, and a lid member 33. The housing-like main body 31 has an opening 34 formed therein for loading and unloading the wafer W. The holding plate 32 holds the wafer W to be processed in a horizontal direction. The lid member 33 supports the holding plate 32 and seals the opening 34 when the wafer W is loaded into the main body 31.

[0047] The main body 31 is a container having a processing space formed therein capable of accommodating a wafer W having a diameter of, for example, 300 (mm), and has a wall provided with supply ports 35, 36 and a discharge port 37. The supply ports 35, 36 and the discharge port 37 are connected to a supply flow path and a discharge flow path, respectively, for circulating a supercritical fluid to the drying unit 18.

[0048] The supply port 35 is connected to the side surface of the housing-like main body 31 opposite to the opening 34. The supply port 36 is connected to the bottom surface of the main body 31. The discharge port 37 is connected to the lower side of the opening 34. Although two supply ports 35, 36 and one discharge port 37 are illustrated in FIG. 4, the numbers of the supply ports 35, 36 and the discharge ports 37 are not particularly limited.

[0049] Further, fluid supply headers 38, 39 and a fluid discharge header 40 are provided inside the main body 31. A plurality of supply ports are formed in the fluid supply headers 38, 39, aligned in the longitudinal direction of the fluid supply headers 38, 39, and a plurality of discharge ports are formed in the fluid discharge header 40, aligned in the longitudinal direction of the fluid discharge header 40.

[0050] The fluid supply header 38 is connected to the supply port 35, and is provided adjacent to the side surface opposite the opening 34 inside the housing-like main body 31. In addition, a plurality of supply ports formed in line on the fluid supply header 38 face the opening 34 side.

[0051] The fluid supply header 39 is connected to the supply port 36, and is provided at the center of the bottom surface inside the housing-like main body 31. Furthermore, a plurality of supply ports formed side by side on the fluid supply header 39 face upward.

[0052] The fluid discharge header 40 is connected to the discharge port 37 and is provided inside the housing-like main body 31 adjacent to the side surface on the opening 34 side and below the opening 34. In addition, a plurality of discharge ports formed next to the fluid discharge header 40 face upward.

[0053] The fluid supply headers 38, 39 supply the supercritical fluid into the main body 31. The fluid discharge header 40 guides the supercritical fluid in the main body 31 to the outside of the main body 31 and discharges it. The supercritical fluid discharged to the outside of the main body 31 via the fluid discharge header 40 contains IPA liquid that has been dissolved in the supercritical fluid in a supercritical state from the upper surface of the wafer W.

[0054] In the drying unit 18, the IPA liquid between the patterns formed on the wafer W is gradually dissolved in the supercritical fluid by contacting the supercritical fluid in a high pressure state (for example, 16 (MPa)), and the spaces between the patterns are gradually replaced by the supercritical fluid. Finally, the spaces between the patterns are filled only with the supercritical fluid.

[0055] Then, after the IPA liquid is removed from between the patterns, the pressure inside the main body 31 is reduced from a high pressure state to atmospheric pressure, whereby the CO2 changes from a supercritical state to a gaseous state, and the spaces between the patterns are occupied only by gas. In this way, the IPA liquid between the patterns is removed, and the drying process of the wafer W is completed.

[0056] Here, the supercritical fluid has a smaller viscosity than a liquid (e.g., IPA liquid), has a higher ability to dissolve liquid, and has no interface between the supercritical fluid and a liquid or gas in equilibrium. As a result, in a drying process using a supercritical fluid, the liquid can be dried without being affected by surface tension. Therefore, according to the embodiment, it is possible to suppress the pattern from collapsing during the drying process.

[0057] In the embodiment, an example is shown in which IPA liquid is used as the liquid for preventing drying, and CO2 in a supercritical state is used as the processing fluid, but a liquid other than IPA may be used as the liquid for preventing drying, and a fluid other than CO2 in a supercritical state may be used as the processing fluid.

[0058] <Substrate processing flow> Next, a processing flow of the wafer W in the above-mentioned substrate processing system 1 will be described with reference to Fig. 5 to Fig. 8. Fig. 5 is a flow chart showing a series of substrate processing procedures executed in the substrate processing system 1 according to the embodiment. The series of substrate processing shown in Fig. 5 to Fig. 8 is executed under the control of the control unit 61.

[0059] 5 to 7. In addition, the procedure shown here is an example of a series of substrate processing steps performed on one wafer W. In the substrate processing system 1, the series of substrate processing steps shown in FIGS.

[0060] In the substrate processing system 1, first, the transfer device 13 takes out the wafer W from the carrier C and places it on the delivery section 14 (step S101). Specifically, the transfer device 13 takes out the wafer W from the carrier C using the wafer holding mechanism, and places the taken-out wafer W on the delivery section 14.

[0061] Next, a first transfer process is performed in the substrate processing system 1 (step S102). In the first transfer process, the transfer device 16 takes out the wafer W from the delivery section 14 and transfers it to the liquid processing unit 17.

[0062] Specifically, transfer device 16 uses the wafer holding mechanism to take out wafer W from delivery section 14, and transfers the taken-out wafer W to liquid processing unit 17 in processing block 5.

[0063] Next, in the substrate processing system 1, liquid processing is performed in the liquid processing unit 17 (step S103). Specifically, the liquid processing unit 17 removes particles, a natural oxide film, and the like from the upper surface of the wafer W by, for example, supplying various chemical liquids and rinsing liquids to the upper surface, which is the pattern formation surface, of the wafer W.

[0064] Next, the liquid processing unit 17 supplies IPA liquid to the upper surface of the wafer W after the cleaning processing, for example, to form a liquid film of the IPA liquid on the upper surface of the wafer W (i.e., wets the upper surface of the wafer W with the IPA liquid). Details of such liquid processing will be described later.

[0065] Next, a second transfer process is performed (step S104) in the substrate processing system 1. The second transfer process is a process in which the transfer device 16 takes out the wafer W having the liquid film formed on the upper surface thereof from the liquid processing unit 17 and transfers it to the drying unit 18.

[0066] Specifically, transfer device 16 uses the wafer holding mechanism to remove wafer W from liquid processing unit 17, and transfers the removed wafer W to corresponding drying unit 18 in processing block 5.

[0067] Next, in the substrate processing system 1, a drying process is performed in the drying unit 18 (step S105). In the drying process, the drying unit 18 dries the wafer W by bringing the wafer W, on which a liquid film has been formed on the upper surface, into contact with a supercritical fluid.

[0068] Next, a third transfer process is performed in the substrate processing system 1 (step S106). The third transfer process is a process in which the transfer device 16 takes out the wafer W after the drying process from the drying unit 18 and transfers it to the delivery section 14.

[0069] Specifically, the transfer device 16 uses the wafer holding mechanism to take out the wafer W from the drying unit 18, and places the taken-out wafer W on the delivery section 14.

[0070] Next, in the substrate processing system 1, the transfer device 13 removes the wafer W from the transfer section 14 and transfers it to the carrier C (step S107). Specifically, the transfer device 13 removes the wafer W from the transfer section 14 using the wafer holding mechanism, and places the removed wafer W on the carrier C. Upon completion of this transfer process, a series of substrate processing steps for one wafer W is completed.

[0071] 6 is a flowchart showing the procedure of the liquid processing (step S103) performed in the substrate processing system 1 according to the embodiment. As shown in FIG. 6, in the liquid processing according to the embodiment, first, the control unit 61 performs the chemical processing in the liquid processing unit 17, supplying the chemical liquid from the chemical liquid nozzle 26a and the chemical liquid supply path 25a to the wafer W (step S201).

[0072] In the process of step S201, for example, the SC1 liquid is supplied to the upper and lower surfaces of the wafer W, thereby removing particles and organic contaminants from the wafer W.

[0073] Next, the control unit 61 performs a rinsing process in which a rinsing liquid is supplied to the wafer W from the chemical liquid nozzle 26a and the chemical liquid supply path 25a in the liquid processing unit 17 (step S202). In the process of step S202, for example, DIW is supplied to the upper and lower surfaces of the wafer W, thereby washing away the SC1 liquid and the like adhering to the wafer W.

[0074] Next, the control unit 61 performs a chemical treatment in the liquid treatment unit 17 by supplying a chemical liquid from the chemical liquid nozzle 26a and the chemical liquid supply path 25a to the wafer W (step S203). In the treatment of step S203, for example, DHF is supplied to the upper and lower surfaces of the wafer W, thereby removing a native oxide film on the wafer W.

[0075] Next, control unit 61 performs a rinsing process in liquid processing unit 17 by supplying a rinsing liquid to wafer W from chemical nozzle 26a and chemical supply path 25a (step S204). In the process of step S204, for example, DIW is supplied to the upper and lower surfaces of wafer W, thereby washing away DHF and the like adhering to wafer W.

[0076] Next, the control unit 61 determines whether the wafer W to be liquid-processed in the liquid processing unit 17 can be transported to a corresponding drying unit 18 (e.g., a drying unit 18 located in the same processing block 5 as the liquid processing unit 17 in which the wafer W is processed) (step S205).

[0077] Then, when the wafer W can be transported to the corresponding drying unit 18 (Yes in step S205), the control unit 61 performs a puddle process in which the IPA liquid is supplied to the wafer W from the chemical nozzle 26a to form a liquid film of the IPA liquid on the upper surface of the wafer W (step S206). As a result, the upper surface of the wafer W becomes wet with the IPA liquid.

[0078] Next, control unit 61 determines whether wafer W to be liquid-processed in liquid processing unit 17 can be transferred to corresponding drying unit 18 (step S207).

[0079] Then, when the wafer W can be transferred to the corresponding drying unit 18 (Yes at step S207), the control unit 61 ends the series of liquid processes, and proceeds to the second transfer process (step S104) shown in FIG.

[0080] On the other hand, in the processing of the above-mentioned step S205, if the wafer W cannot be transported to the corresponding drying unit 18 (step S205, No), for example, if the corresponding drying unit 18 cannot operate due to a malfunction or the like, the control unit 61 performs a liquid supply process (step S208).

[0081] Similarly, in the process of step S207 described above, if the wafer W cannot be transported to the corresponding drying unit 18 (step S207, No), the control unit 61 performs a liquid supply process (step S208).

[0082] The liquid supply process is a process of continuously supplying the processing liquid to the wafer W in the liquid processing unit 17. This makes it possible to prevent the upper surface of the wafer W, which cannot be transported to the corresponding drying unit 18 and is in a waiting state in the liquid processing unit 17, from drying.

[0083] Therefore, according to the embodiment, defects such as collapse of the pattern formed on the wafer W can be suppressed, and the yield of the wafer W can be improved.

[0084] The processing liquid supplied to the wafer W in this liquid supply process may be, for example, any one of DIW, IPA, and diluted IPA (i.e., a mixture of DIW and IPA). This makes it possible to suppress drying of the upper surface of the wafer W without changing the state of the upper surface of the wafer W. Therefore, according to the embodiment, the yield of the wafer W can be further improved.

[0085] In addition, by using DIW, which is inexpensive and does not dry out easily, as the processing liquid supplied to the wafer W in this liquid supply process, the amount of processing liquid used can be reduced, thereby reducing the cost of the liquid supply process.

[0086] In the present disclosure, the processing liquid supplied to the wafer W in the liquid supply process is not limited to DIW, IPA, and diluted IPA, and may be any processing liquid that does not change the state of the top surface of the wafer W.

[0087] In addition, in this liquid supply process, the processing liquid may be continuously or intermittently supplied to the upper surface of the wafer W. For example, by continuously supplying the processing liquid in the liquid supply process, it is possible to more reliably prevent the upper surface of the wafer W from drying.

[0088] Furthermore, by intermittently supplying the processing liquid in the liquid supplying process, the amount of processing liquid used can be reduced, and therefore the cost of the liquid supplying process can be reduced.

[0089] Furthermore, when the supply of the processing liquid to the upper surface of the wafer W is continued intermittently, the time during which the supply of the processing liquid to the wafer W is interrupted is preferably the time during which the amount of the processing liquid volatilizing from the upper surface of the wafer W becomes smaller than the amount of the liquid film on the upper surface of the wafer W. This makes it possible to more reliably prevent the upper surface of the wafer W from drying out.

[0090] Returning to the description of Fig. 6, following the process of step S208, control unit 61 determines whether wafer W to which the supply of the processing liquid in liquid processing unit 17 continues can be transported to corresponding drying unit 18 (step S209).

[0091] Then, if the wafer W can be transferred to the corresponding drying unit 18 (Yes in step S209), the process proceeds to step S206.

[0092] On the other hand, if the wafer W cannot be transported to the corresponding drying unit 18 (No at step S209), the control unit 61 determines whether the supply of the processing liquid to the wafer W has continued for a given period of time (step S210).

[0093] If the supply of the processing liquid to the wafer W has not continued for the given time (No in step S210), the process returns to step S208.

[0094] On the other hand, if the supply of the processing liquid to the wafer W has continued for a given time (Yes in step S210), the control unit 61 determines that the drying unit 18 is not expected to be restored, and forcibly removes the waiting wafer W from the substrate processing system 1 (step S211). This makes it possible to prevent unnecessary use of the processing liquid.

[0095] Then, the waiting wafer W is forcibly unloaded from the substrate processing system 1, and a series of liquid processing is completed. In this case, the drying process (step S105) for the wafer W may not be performed.

[0096] In addition, in an embodiment, if in the processing of the above-mentioned step S209, it is determined whether the wafer W can be transported to the corresponding drying unit 18, it may be determined whether the wafer W can be transported to a drying unit 18 that does not correspond to the liquid processing unit 17 in which the wafer W is waiting.

[0097] For example, a plurality of wafers W (for example, 25 wafers) accommodated in one carrier C are associated with each of the plurality of processing blocks 5, and are processed in each processing block 5 in turn.

[0098] In an embodiment, after processing of all wafers W has been completed in a processing block 5 where no malfunctions or the like have occurred, the wafers W waiting in the liquid processing unit 17 of the processing block 5 where a malfunction or the like has occurred may be transported to a drying unit 18 of another processing block 5.

[0099] As a result, even if there is no prospect of recovery for drying unit 18 in a certain processing block 5, wafers W waiting in liquid processing units 17 can be dried without any problems. Therefore, according to the embodiment, the yield of wafers W can be further improved.

[0100] The procedure of this substrate processing will be described in detail with reference to Figures 7 and 8. Figure 7 is a diagram for explaining another example of the substrate processing performed in the substrate processing system 1 according to the embodiment.

[0101] As shown in FIG. 7, in another example of liquid processing, first, control unit 61 performs chemical processing in liquid processing unit 17, supplying a chemical liquid from chemical nozzle 26a and chemical supply path 25a to wafer W (step S301).

[0102] Next, control unit 61 performs a rinsing process in liquid processing unit 17 by supplying a rinsing liquid to wafer W from chemical liquid nozzle 26a and chemical liquid supply path 25a (step S302).

[0103] Next, control unit 61 performs chemical processing in liquid processing unit 17 by supplying a chemical liquid from chemical nozzle 26a and chemical supply path 25a onto wafer W (step S303).

[0104] Next, control unit 61 performs a rinsing process in liquid processing unit 17 by supplying a rinsing liquid to wafer W from chemical liquid nozzle 26a and chemical liquid supply path 25a (step S304).

[0105] Next, the control unit 61 determines whether the wafer W to be liquid-processed in the liquid processing unit 17 can be transported to a corresponding drying unit 18 (e.g., a drying unit 18 located in the same processing block 5 as the liquid processing unit 17 in which the wafer W is processed) (step S305).

[0106] Then, if the wafer W can be transported to the corresponding drying unit 18 (step S305, Yes), the control unit 61 supplies IPA liquid from the chemical nozzle 26a to the wafer W to perform a puddle process to form a liquid film of IPA liquid on the upper surface of the wafer W (step S306).

[0107] Next, control unit 61 determines whether wafer W to be liquid-processed in liquid processing unit 17 can be transferred to corresponding drying unit 18 (step S307).

[0108] Then, when the wafer W can be transferred to the corresponding drying unit 18 (Yes in step S307), the control unit 61 ends the series of liquid processes, and proceeds to the second transfer process (step S104) shown in FIG.

[0109] On the other hand, if the wafer W cannot be transported to the corresponding drying unit 18 in the processing of step S305 described above (step S305, No), for example, if the corresponding drying unit 18 cannot operate due to a malfunction or the like, the control unit 61 performs a liquid supply process (step S308).

[0110] Similarly, in the process of step S307 described above, if the wafer W cannot be transported to the corresponding drying unit 18 (step S307, No), the control unit 61 performs a liquid supply process (step S308).

[0111] The processing in steps S301 to S308 explained so far is similar to the processing in steps S201 to S208 mentioned above, and therefore detailed explanation will be omitted.

[0112] Following the process of step S308, control unit 61 determines whether or not wafer W, to which the supply of the processing liquid in liquid processing unit 17 continues, can be transported to the corresponding drying unit 18 (step S309).

[0113] Then, if the wafer W can be transferred to the corresponding drying unit 18 (Yes in step S309), the process proceeds to step S306.

[0114] On the other hand, if the wafer W cannot be transported to the corresponding drying unit 18 (No at step S309), the control unit 61 determines whether the project to which the wafer W belongs has been completed (step S310).

[0115] Here, an example of a flow of processing a plurality of wafers W in the substrate processing system 1, including a concept of a project to which the wafers W belong, will be described with reference to Fig. 8. Fig. 8 is a diagram for explaining another example of substrate processing executed in the substrate processing system 1 of the embodiment.

[0116] In the example of FIG. 8, one substrate processing system 1 is provided with three liquid processing units 17 and three drying units 18, which are referred to as liquid processing units A to C and drying units A to C, respectively.

[0117] 8, "liquid processing unit A" and "drying unit A" correspond to each other, "liquid processing unit B" and "drying unit B" correspond to each other, and "liquid processing unit C" and "drying unit C" correspond to each other. Mutually corresponding liquid processing units 17 and drying units 18 are located in, for example, the same processing block 5 (see FIG. 2).

[0118] 8, for ease of understanding, the number of wafers W accommodated in one carrier C is set to nine (denoted as wafers A1 to A9 in the figure). Then, the control unit 61 (see FIG. 1) sets, for example, one project for each carrier C, and collectively processes the nine wafers W accommodated in the corresponding carrier C in the project.

[0119] 8, when one project is started, control unit 61 (see FIG. 1) controls transfer device 16 (see FIG. 1) to transfer wafer A1 to liquid processing unit A (step S102). Then, control unit 61 performs liquid processing on wafer A1 in liquid processing unit A (step S103).

[0120] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A2 to the liquid processing unit B (step S102). Then, the control unit 61 performs liquid processing on the wafer A2 in the liquid processing unit B (step S103).

[0121] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A3 to the liquid processing unit C (step S102). Then, the control unit 61 performs liquid processing on the wafer A3 in the liquid processing unit C (step S103).

[0122] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A1, which has been subjected to the given liquid treatment, from the liquid treatment unit A to the drying unit A (step S104). Then, the control unit 61 performs a drying process on the wafer A1 in the drying unit A (step S105).

[0123] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A2, which has been subjected to the given liquid treatment, from the liquid treatment unit B to the drying unit B (step S104). Then, the control unit 61 performs a drying process on the wafer A2 in the drying unit B (step S105).

[0124] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A3, which has been subjected to the given liquid treatment, from the liquid treatment unit C to the drying unit C (step S104). Then, the control unit 61 performs a drying process on the wafer A3 in the drying unit C (step S105).

[0125] As described above, in the embodiment, controller 61 transfers wafer W that has been subjected to liquid processing in liquid processing unit 17 to corresponding drying unit 18, where it is subjected to drying processing.

[0126] This reduces variation in the transport time from liquid processing unit 17 to drying unit 18 among multiple wafers W. Therefore, according to the embodiment, the liquid film state at the start of the drying process can be made uniform among multiple wafers W, thereby improving the yield of substrate processing in substrate processing system 1.

[0127] Returning to the description of Fig. 8, next, control unit 61 controls transfer device 16 to transfer wafer A4 to liquid processing unit A (step S102). Then, control unit 61 performs liquid processing on wafer A4 in liquid processing unit A (step S103).

[0128] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A5 to the liquid processing unit B (step S102). Then, the control unit 61 performs liquid processing on the wafer A5 in the liquid processing unit B (step S103).

[0129] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A6 to the liquid processing unit C (step S102). Then, the control unit 61 performs liquid processing on the wafer A6 in the liquid processing unit C (step S103).

[0130] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A4, which has been subjected to the given liquid treatment, from the liquid treatment unit A to the drying unit A (step S104). Then, the control unit 61 performs a drying process on the wafer A4 in the drying unit A (step S105).

[0131] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A7 to the liquid processing unit A (step S102). Then, the control unit 61 performs liquid processing on the wafer A7 in the liquid processing unit A (step S103).

[0132] 8, it is assumed that a problem occurs in drying unit A during drying processing of wafer A4. In this case, control unit 61 determines that wafer A7 undergoing liquid processing in liquid processing unit A corresponding to this drying unit A cannot be transported to drying unit A (step S305, No).

[0133] Therefore, control unit 61 performs a predetermined liquid supplying process on wafer A7 in liquid processing unit A (step S308). For example, in the example of Fig. 8, DIW is supplied as a liquid supplying process to wafer A7 after the predetermined liquid processing (steps S301 to S304).

[0134] In parallel with the various processes for wafer A7, control unit 61 controls transfer device 16 to transfer wafer A5, which has been subjected to a given liquid process, from liquid processing unit B to drying unit B (step S104). Then, control unit 61 performs a drying process on wafer A5 in drying unit B (step S105).

[0135] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A6, which has been subjected to the given liquid treatment, from the liquid treatment unit C to the drying unit C (step S104). Then, the control unit 61 performs a drying process on the wafer A6 in the drying unit C (step S105).

[0136] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A8 to the liquid processing unit B (step S102). Then, the control unit 61 performs liquid processing on the wafer A8 in the liquid processing unit B (step S103).

[0137] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A9 to the liquid processing unit C (step S102). Then, the control unit 61 performs liquid processing on the wafer A9 in the liquid processing unit C (step S103).

[0138] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A8, which has been subjected to the given liquid treatment, from the liquid treatment unit B to the drying unit B (step S104). Then, the control unit 61 performs a drying process on the wafer A8 in the drying unit B (step S105).

[0139] Next, the control unit 61 controls the transfer device 16 to transfer the wafer A9, which has been subjected to the given liquid treatment, from the liquid treatment unit C to the drying unit C (step S104). Then, the control unit 61 performs a drying process on the wafer A9 in the drying unit C (step S105).

[0140] Then, when the wafer A9, for which the drying process has been completed, is carried out of the drying unit C by the transfer device 16, one project for the wafers A1 to A9 is completed.

[0141] 8, even when this project is completed, the trouble in drying unit A continues. Therefore, as shown in FIG 7, control unit 61 determines that wafer A7 located in liquid processing unit A cannot be transported to the corresponding drying unit A (step S309, No) and determines that the project to which wafer A7 belongs has been completed (step S310, Yes).

[0142] Next, controller 61 determines whether wafer A7 located in liquid processing unit A can be transferred to drying unit B or drying unit C other than the corresponding drying unit A (step S311).

[0143] If it is determined that the wafer A7 can be transported to another drying unit B or drying unit C (Yes in step S311), the control unit 61 performs a puddle process to form a film of IPA liquid on the upper surface of the wafer A7 (step S312). Then, the control unit 61 ends the series of liquid processes and proceeds to the second transport process (step S104) shown in FIG.

[0144] In the example of FIG. 8, since it is determined in the process of step S311 that the wafer can be transported to another drying unit B, the control unit 61 performs the puddle process on the wafer A7 from the point when the project is completed.

[0145] Then, the control unit 61 controls the transfer device 16 to transfer the wafer A7 that has been subjected to the puddle process to the drying unit B (step S104), and the wafer A7 is subjected to a drying process in the drying unit B (step S105).

[0146] As a result, even if one of the multiple drying units 18 cannot operate due to a problem or the like, it is possible to salvage the wafers W to be processed in that drying unit 18. Therefore, according to the embodiment, it is possible to further improve the yield of the wafers W.

[0147] In addition, in the embodiment, by processing wafers A8 and A9, which are different from wafer A7 waiting in liquid processing unit A1, before wafer A7, it is possible to prevent processing times of wafers A8 and A9 from being disrupted due to wafer A7 being processed first in another drying unit B. Therefore, according to the embodiment, the yield of wafers W can be further improved.

[0148] In the embodiment, the wafer A7 that has been dried in the drying units B and C other than the corresponding drying unit A as described above may be treated as a warning substrate. This allows the warning substrate to be subjected to a process different from that for the other wafers W, thereby further improving the yield of the wafers W.

[0149] Returning to the description of FIG. 7, if it is determined in the process of step S311 that the wafer cannot be transported to the other drying units B and C (No in step S311), the control unit 61 determines that recovery of all the drying units A to C is not in sight. Then, the control unit 61 forcibly transports the wafer A7 waiting in the liquid processing unit A out of the substrate processing system 1 (step S313). This makes it possible to prevent unnecessary use of the processing liquid.

[0150] In the embodiment, a user may visually perform the processes of steps S209 and S311 and manually perform the processes of steps S211 and S313. On the other hand, by having the control unit 61 automatically perform the processes of steps S209, S211, and S313, it is possible to prevent unnecessary use of the processing liquid even when the user is away from the substrate processing system 1.

[0151] In an embodiment, if it is determined during the second transport process shown in FIG. 5 that the wafer W cannot be transported to the drying unit 18 to which it is to be transported, the wafer W being transported may be returned to the liquid processing unit 17, and a liquid supply process (steps S208, S308) may be performed on the wafer W.

[0152] This makes it possible to prevent the upper surface of the wafer W from drying, thereby improving the yield of the wafer W.

[0153] The substrate processing method according to the embodiment includes a liquid processing step (step S103), a transport step (step S104), and a supercritical step (step S105). In the liquid processing step (step S103), liquid processing is performed on the substrate (wafer W) in the liquid processing section (liquid processing unit 17) to wet the upper surface of the substrate (wafer W). In the transport step (step S104), the substrate (wafer W) whose upper surface is wet is transported from the liquid processing section (liquid processing unit 17) to the supercritical processing section (drying unit 18). In the supercritical step (step S105), the substrate (wafer W) whose upper surface is wet is treated with a supercritical fluid in the supercritical processing section (drying unit 18). In addition, in the liquid processing step (step S103), if it is determined that the substrate (wafer W) cannot be transported to the supercritical processing section (drying unit 18), the supply of the processing liquid to the substrate (wafer W) is continued. This can improve the yield of the wafer W.

[0154] Moreover, in the substrate processing method according to the embodiment, the liquid processing step (step S103) is performed in a plurality of liquid processing sections (liquid processing units 17), and the supercritical step (step S105) is performed in a plurality of supercritical processing sections (drying units 18). Moreover, in the liquid processing step (step S103), if it is determined that the substrate (wafer W) cannot be transported to the supercritical processing section (drying unit 18), the supply of processing liquid to the substrate (wafer W) continues until the project to which the substrate (wafer W) belongs is completed. This makes it possible to improve the yield of wafers W.

[0155] In the substrate processing method according to the embodiment, when a project is completed and it is determined that the substrate can be transported to a supercritical processing unit different from the supercritical processing unit to which the substrate cannot be transported, the transport step (step S104) transports the substrate to the different supercritical processing unit, thereby improving the yield of the wafers W.

[0156] In the substrate processing method according to the embodiment, the substrate (wafer W) transferred to a different supercritical processing section (drying unit 18) is treated as a warning substrate in the subsequent processing, thereby improving the yield of the wafer W.

[0157] In the substrate processing method according to the embodiment, the liquid processing step (step S103) continues to supply the processing liquid to the substrate if it is determined that the substrate cannot be transported to the supercritical processing unit (drying unit 18) during the period from when the supply of the processing liquid is started to when the supply is stopped. This can improve the yield of the wafers W.

[0158] In the substrate processing method according to the embodiment, the liquid processing step (step S103) restarts the supply of the processing liquid to the substrate (wafer W) if it is determined that the substrate (wafer W) cannot be transported to the supercritical processing unit (drying unit 18) after the supply of the processing liquid is stopped. This makes it possible to improve the yield of the wafer W.

[0159] In the substrate processing method according to the embodiment, when it is determined that the substrate can be transported to the supercritical processing unit, a step (step S206) of wetting the top surface of the substrate in the liquid processing step (step S103) is performed, and then a transport step (step S105) is performed. This makes it possible to prevent unnecessary use of the processing liquid.

[0160] Furthermore, in the substrate processing method according to the embodiment, if it is determined that the substrate (wafer W) cannot be transported to the supercritical processing unit (drying unit 18), the liquid processing step (step S103) continues to supply the processing liquid to the substrate (wafer W) for a given time. Then, if a time equal to or longer than the given time has elapsed, the supply of the processing liquid to the substrate (wafer W) is stopped. This makes it possible to prevent unnecessary use of the processing liquid.

[0161] In the substrate processing method according to the embodiment, when it is determined that the substrate (wafer W) cannot be transported to the supercritical processing section (drying unit 18), the liquid processing step (step S103) continues to intermittently supply the processing liquid to the substrate (wafer W). This makes it possible to reduce costs in the liquid supply process.

[0162] In addition, in the substrate processing method according to the embodiment, when the supply of the processing liquid to the substrate (wafer W) is continued intermittently, the time during which the supply of the processing liquid to the substrate (wafer W) is interrupted is the time during which the amount of the processing liquid volatilized from the upper surface of the substrate becomes smaller than the amount of the liquid film on the upper surface of the substrate. This makes it possible to more reliably prevent the upper surface of the wafer W from drying.

[0163] In the substrate processing method according to the embodiment, the transfer step (step S105) is performed by selecting a supercritical processing unit (drying unit 18) that is determined to be capable of being transferred from among the plurality of supercritical processing units (drying units 18). This can further improve the yield of wafers W.

[0164] Moreover, the substrate processing apparatus (substrate processing system 1) according to the embodiment includes a liquid processing section (liquid processing unit 17), a supercritical processing section (drying unit 18), a transfer section (transport device 16), and a control section 61. The liquid processing section (liquid processing unit 17) performs liquid processing on the substrate (wafer W). The supercritical processing section (drying unit 18) processes the substrate (wafer W) with a supercritical fluid. The transfer section (transport device 16) transfers the substrate (wafer W) from the liquid processing section (liquid processing unit 17) to the supercritical processing section (drying unit 18). The control section 61 controls each section. Moreover, the control section 61 wets the upper surface of the substrate (wafer W) in the liquid processing section (liquid processing unit 17), and transfers the substrate (wafer W) with the wet upper surface from the liquid processing section (liquid processing unit 17) to the supercritical processing section (drying unit 18) by the transfer section (transport device 16). Furthermore, the control unit 61 processes the substrate (wafer W) whose upper surface is wet with the supercritical fluid in the supercritical processing unit (drying unit 18). Furthermore, when it is determined that the substrate (wafer W) cannot be transported to the supercritical processing unit (drying unit 18), the control unit 61 continues to supply the processing liquid to the substrate (wafer W) in the liquid processing unit (liquid processing unit 17). This makes it possible to improve the yield of the wafer W.

[0165] Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present disclosure. For example, in the above embodiment, the substrate processing system 1 is provided with one transfer device 16, but the number of transfer devices 16 is not limited to one. For example, the transfer device 16 may be provided in multiple pairs of liquid processing units 17 and drying units 18, as long as the transfer device 16 is provided in common to each of the multiple pairs of liquid processing units 17 and drying units 18.

[0166] In the above embodiment, an example has been described in which one project is set for each carrier C and multiple wafers W are processed on a project-by-project basis, but the present disclosure is not limited to such an example. For example, one project may be set for multiple carriers C, or multiple projects may be set for one carrier C.

[0167] The disclosed embodiments should be considered to be illustrative and not restrictive in all respects. Indeed, the above-described embodiments may be embodied in various forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0168] W wafer (example of substrate) 1. Substrate processing system (an example of a substrate processing apparatus) 16 Conveying device (an example of a conveying section) 17 Liquid processing unit (an example of a liquid processing section) 18 Drying unit (an example of a supercritical processing unit) 61 Control section

Claims

1. In the liquid treatment section, a liquid treatment step is performed on the substrate to wet the upper surface of the substrate, A transport step of transporting the substrate, whose upper surface is wet, from the liquid processing unit to the supercritical processing unit, The supercritical processing unit includes a supercritical step in which the substrate, whose upper surface is wet, is treated with a supercritical fluid, Includes, The liquid treatment process is carried out in a plurality of liquid treatment units. The supercritical process is carried out in a plurality of supercritical processing units. If it is determined that the substrate cannot be transported to the supercritical processing unit, the transport process transports the substrate to a different supercritical processing unit than the one to which it was determined that transport is not possible. Substrate processing method.

2. The liquid treatment step and the supercritical step are performed between the corresponding liquid treatment section and the supercritical treatment section, If it is determined that the substrate cannot be transported to the corresponding supercritical processing unit, the transport process transports the substrate to a supercritical processing unit different from the corresponding supercritical processing unit. The substrate processing method according to claim 1.

3. The transport process involves transporting the substrate to a different supercritical processing unit after the project to which the substrate belongs has been completed. The substrate processing method according to claim 1 or 2.

4. The substrates transported to different supercritical processing units are treated as warning substrates in subsequent processing. The substrate processing method according to claim 3.

5. The liquid treatment step and the supercritical step are performed between the corresponding liquid treatment unit and the supercritical treatment unit, The transport distance of the substrate between multiple corresponding liquid processing units and supercritical processing units is all equal. The substrate processing method according to claim 1 or 2.

6. The liquid treatment step and the supercritical step are performed between the corresponding liquid treatment unit and the supercritical treatment unit, Multiple corresponding liquid processing units and supercritical processing units are arranged stacked in the vertical direction. The substrate processing method according to claim 1 or 2.

7. The liquid treatment step and the supercritical step are performed between the corresponding liquid treatment unit and the supercritical treatment unit, Multiple corresponding liquid processing units and supercritical processing units are arranged on the side of one or more transport units. The substrate processing method according to claim 1 or 2.

8. A plurality of corresponding liquid processing units and supercritical processing units are arranged on the side of one of the transport units. The substrate processing method according to claim 7.

9. Multiple liquid processing units that perform liquid processing on a substrate, Multiple supercritical processing units for processing the substrate with a supercritical fluid, One or more transport units for transporting the substrate from the liquid processing unit to the supercritical processing unit, A control unit that controls each part, Equipped with, The control unit, In the liquid treatment section, the upper surface of the substrate is wetted. The transport unit transports the substrate, whose upper surface has been wetted, from the liquid processing unit to the supercritical processing unit. In the supercritical processing unit, the substrate whose upper surface is wet is treated with a supercritical fluid. If it is determined that the substrate cannot be transported to the supercritical processing unit, the substrate is transported to a different supercritical processing unit than the one to which it was determined that transport is not possible. Circuit board processing equipment.

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