Substrate processing apparatus and substrate drying method

Abstract

The present invention provides a substrate processing apparatus and a substrate drying method. The substrate processing apparatus of the present invention is capable of performing a drying process of drying a substrate having a liquid film formed on a pattern formation surface using a processing fluid in a supercritical state, and includes a processing container, a holding portion, and a supply portion. The processing container accommodates the substrate. The holding portion holds the substrate inside the processing container. The supply portion supplies the processing fluid inside the processing container. Further, the holding portion includes a base portion, a plurality of support members, and a lifting mechanism. The base portion is disposed below the substrate. The plurality of support members are provided on the base portion and are capable of supporting the substrate from below. The lifting mechanism lifts and lowers the plurality of support members. The present invention is capable of suppressing collapse of a pattern formed on the upper surface of the substrate in a technique of drying the substrate using the processing fluid in the supercritical state.

Description

TECHNICAL FIELD

[0001] The present application relates to a substrate processing apparatus and a substrate drying method. BACKGROUND

[0002] Conventionally, there is known a technique in which, in a drying process after a liquid is applied to an upper surface of a substrate such as a semiconductor wafer, the substrate in a state in which the upper surface is wetted with the liquid is brought into contact with a processing fluid in a supercritical state to dry the substrate.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-251550 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] An object of the present application is to provide a technique capable of suppressing pattern collapse of a pattern formed on an upper surface of a substrate in a technique of drying the substrate using a processing fluid in a supercritical state.

[0008] MEANS OF SOLVING THE PROBLEMS

[0009] A substrate processing apparatus of one embodiment of the present application is capable of performing a drying process of drying a substrate on which a liquid film is formed on a pattern formation surface using a processing fluid in a supercritical state, and includes a processing container, a holding portion, and a supply portion. The processing container accommodates the substrate. The holding portion holds the substrate inside the processing container. The supply portion supplies the processing fluid inside the processing container. Furthermore, the holding portion includes a base portion, a plurality of support members, and a lifting mechanism. The base portion is disposed below the substrate. The plurality of support members are provided on the base portion and are capable of supporting the substrate from below. The lifting mechanism lifts the plurality of support members.

[0010] EFFECTS OF THE INVENTION

[0011] According to the present application, in a technique of drying a substrate using a processing fluid in a supercritical state, pattern collapse of a pattern formed on an upper surface of the substrate can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is a diagram showing the configuration of a substrate processing system according to an embodiment.

[0013] Figure 2 FIG. 2 is a diagram showing the configuration of a liquid processing unit according to an embodiment.

[0014] Figure 3 FIG. 3 is an external perspective view of a drying processing unit according to an embodiment.

[0015] Figure 4 is a plan view of the holding section of the embodiment.

[0016] Figure 5 is a side cross-sectional view of the holding section of the embodiment.

[0017] Figure 6 is a diagram showing the arrangement of the displacement sensor and the film thickness sensor of the embodiment.

[0018] Figure 7 is a block diagram showing the configuration of the control device of the embodiment.

[0019] Figure 8 is a diagram showing an example of the flow of the supercritical fluid in the processing space.

[0020] Figure 9 is a diagram showing an example of the lift control processing using the usage plan information or the liquid amount information.

[0021] Figure 10 is a diagram showing an example of the case where the support member is raised in accordance with the liquid amount of the liquid film changing in the drying processing.

[0022] Figure 11 is a diagram showing an example of the case where the support member is lowered in accordance with the liquid amount of the liquid film changing in the drying processing.

[0023] Figure 12 is a diagram showing an example of the height position of the wafer in the drying processing.

[0024] Figure 13 is a diagram showing an example of the case where the height position of the wafer is changed in accordance with the wafer temperature information.

[0025] Figure 14 is a diagram showing an example of the case where the wafer supported by the plurality of support members is tilted.

[0026] Figure 15 is a diagram showing an example of the case where the tilted wafer is eliminated by the lift control processing.

[0027] Figure 16 is a diagram showing the arrangement of the film thickness sensor of the modification.

[0028] Explanation of Reference Numerals

[0029] W wafer

[0030] 1 substrate processing system

[0031] 2 in-out station

[0032] 3 processing station

[0033] 5 processing block

[0034] 17 liquid processing unit

[0035] 18 drying processing unit

[0036] 19 supply unit

[0037] 31 processing container

[0038] 32 holding section

[0039] 32a base section

[0040] 32b support member

[0041] 32c lifting mechanism

[0042] 32d through-hole

[0043] 33 lid

[0044] 39 lifter

[0045] 40 weight sensor

[0046] 61 control section

[0047] 61a information acquisition section

[0048] 61b lifting control section

[0049] 62 storage section

[0050] 62a scheme information

[0051] 62b liquid film change information

[0052] 62c wafer temperature information

[0053] 62d liquid amount information

[0054] 62e inclination information

[0055] 62f film thickness distribution information DETAILED DESCRIPTION

[0056] Hereinafter, modes of a substrate processing apparatus and a substrate drying method for carrying out the present application (hereinafter referred to as "embodiments") will be explained in detail with reference to the drawings. Further, the substrate processing apparatus and the substrate drying method of the present application are not limited by the embodiments. In addition, each of the embodiments can be appropriately combined within a range not to contradict the processing contents. In addition, the same reference numerals are attached to the same parts in each of the following embodiments, and the repeated explanation will be omitted.

[0057] In addition, in each of the drawings referred to below, in order to make the explanation easy to understand, sometimes a Z-axis direction orthogonal to an X-axis direction and a Y-axis direction is shown, and an orthogonal coordinate system with the positive direction of the Z-axis as the vertical upward direction is shown. Further, sometimes a rotation direction with the vertical axis as the center of rotation is referred to as a θ direction.

[0058] In addition, in the embodiments shown below, sometimes descriptions such as "certain", "orthogonal", "perpendicular", or "parallel" are used, and these descriptions do not need to be "certain", "orthogonal", "perpendicular", or "parallel" strictly. That is, each of the above-described descriptions allows for errors in manufacturing precision, setting precision, and the like.

[0059] (1. Configuration of the substrate processing system)

[0060] First, the configuration of the substrate processing system of the embodiment will be described with reference to Figure 1 to FIG. 1. Figure 1 is a view showing the configuration of the substrate processing system of the embodiment.

[0061] As shown in Figure 1 , the substrate processing system 1 includes an in-out station 2 and a processing station 3. The in-out station 2 and the processing station 3 are arranged adjacent to each other.

[0062] The in-out station 2 includes a carrier placement portion 11 and a conveying portion 12. The carrier placement portion 11 places a plurality of carriers C that house a plurality of semiconductor wafers (hereinafter referred to as "wafers W") in a horizontal state.

[0063] The conveying portion 12 is arranged adjacent to the carrier placement portion 11. Inside the conveying portion 12, a conveying device 13 and a handover portion 14 are arranged.

[0064] The conveying device 13 includes a wafer holding mechanism that holds the wafers W. Further, the conveying device 13 is movable in a horizontal direction and a vertical direction and is rotatable about the vertical axis, and is capable of conveying the wafers W between the carriers C and the handover portion 14 using the wafer holding mechanism.

[0065] The processing station 3 is arranged adjacent to the conveying portion 12. The processing station 3 includes a conveying portion 15 and a plurality of processing blocks 16.

[0066] The conveying block 4 includes a conveying region 15 and a conveying device 16. The conveying region 15 is, for example, a cuboid-shaped region extending in a direction (X-axis direction) in which the in-out station 2 and the processing station 3 are arranged side by side. The conveying device 16 is arranged in the conveying region 15.

[0067] The transport device 16 includes a wafer holding mechanism that holds the wafer W. In addition, the transport device 16 is movable in the horizontal direction and the vertical direction and is rotatable about a vertical axis, and is capable of transporting the wafer W between the handoff section 14 and the plurality of processing blocks 5 using the wafer holding mechanism.

[0068] The plurality of processing blocks 5 are arranged adjacent to the transport region 15 on both sides of the transport region 15. Specifically, the plurality of processing blocks 5 are arranged on one side (Y-axis positive direction side) and the other side (Y-axis negative direction side) of the transport region 15 in a direction (Y-axis direction) orthogonal to a direction (X-axis direction) in which the in-out station 2 and the processing station 3 are arranged side by side.

[0069] Each of the processing blocks 5 includes a liquid processing unit 17, a dry processing unit 18, and a supply unit 19.

[0070] The liquid processing unit 17 performs a cleaning process that cleans a pattern formation surface, i.e., an upper surface, of the wafer W. In addition, the liquid processing unit 17 performs a liquid film formation process that forms a liquid film on the upper surface of the wafer W after the cleaning process. The configuration of the liquid processing unit 17 will be described later.

[0071] The dry processing unit 18 performs a supercritical drying process on the wafer W after the liquid film formation process. Specifically, the dry processing unit 18 dries the wafer W after the liquid film formation process by bringing the wafer W into contact with a processing fluid in a supercritical state.

[0072] The dry processing unit 18 includes a processing region 181 that performs the supercritical drying process, and a handoff region 182 that performs handoff of the wafer W between the transport block 4 and the processing region 181. The processing region 181 and the handoff region 182 are arranged along the transport region 15. The specific configuration of the dry processing unit 18 will be described later.

[0073] The supply unit 19 supplies the processing fluid to the dry processing unit 18. Specifically, the supply unit 19 includes a supply device group having a flow meter, a flow regulator, a back pressure valve, a heater, and the like, and a housing that houses the supply device group. In the embodiment, the supply unit 19 supplies CO2 as the processing fluid to the dry processing unit 18.

[0074] The substrate processing system 1 includes a control device 6. The control device 6 is, for example, a computer, and includes a control section 61 and a storage section 62. The configuration of the control device 6 will be described later.

[0075] (2. Configuration of the liquid processing unit)

[0076] Next, the configuration of the liquid processing unit 17 will be described with reference to FIG. 2. Figure 2 The configuration of the liquid processing unit 17 will be described. Figure 2is a view showing the configuration of the liquid processing unit 17 according to the embodiment. The liquid processing unit 17 is configured as a single-wafer cleaning apparatus that cleans the wafer W one by one by spin cleaning, for example.

[0077] As shown in Figure 2 , the liquid processing unit 17 holds the wafer W substantially horizontally by a wafer holding mechanism 25 disposed in an outer chamber 23 that forms a processing space, and rotates the wafer W by rotating the wafer holding mechanism 25 about a vertical axis. Then, the liquid processing unit 17 makes a nozzle arm 26 enter above the rotating wafer W, and supplies a chemical liquid, a rinsing liquid from a chemical liquid nozzle 26a provided at a front end portion of the nozzle arm 26 in a predetermined order, thereby performing a cleaning process of the upper surface of the wafer W.

[0078] In addition, in the liquid processing unit 17, a chemical liquid supply passage 25a is also formed inside the wafer holding mechanism 25. Then, the lower surface of the wafer W is also cleaned with the chemical liquid and the rinsing liquid supplied from the chemical liquid supply passage 25a.

[0079] The cleaning process, for example, first removes particulate and organic contaminants with an SC1 liquid (a mixture of ammonia and hydrogen peroxide aqueous solution) as an alkaline chemical liquid, and then performs rinsing cleaning with deionized water (hereinafter referred to as "DIW") as a rinsing liquid. Then, a natural oxide film is removed with a diluted hydrofluoric acid aqueous solution (hereinafter referred to as "DHF") as an acidic chemical liquid, and then rinsing cleaning is performed with DIW.

[0080] The above-described various chemical liquids are received by the outer chamber 23 and an inner cup 24 disposed in the outer chamber 23, and are discharged from a liquid discharge port 23a provided at the bottom of the outer chamber 23 and a liquid discharge port 24a provided at the bottom of the inner cup 24. Also, the atmosphere in the outer chamber 23 is exhausted from an exhaust port 23b provided at the bottom of the outer chamber 23.

[0081] The liquid film formation process is performed after the rinsing process in the cleaning process. Specifically, the liquid processing unit 17 supplies IPA liquid to the upper surface and the lower surface of the wafer W while rotating the wafer holding mechanism 25. Thus, the DIW remaining on both surfaces of the wafer W is replaced with IPA. Thereafter, the liquid processing unit 17 slowly stops the rotation of the wafer holding mechanism 25.

[0082] The wafer W, on which the liquid film of IPA liquid is formed on the upper surface, is delivered to the transport device 16 by a not-shown handoff mechanism provided to the wafer holding mechanism 25, and is sent out from the liquid processing unit 17. The liquid film formed on the wafer W can prevent pattern collapse due to evaporation (vaporization) of the liquid on the upper surface of the wafer W during the course of transporting the wafer W from the liquid processing unit 17 to the drying processing unit 18 and the operation of sending the wafer W to the drying processing unit 18.

[0083] (3. Configuration of Drying Unit)

[0084] Next, the configuration of the drying processing unit 18 will be described with reference to Figures 3-6 Figure 3 is a perspective view of the drying processing unit 18 according to the embodiment. Figure 4 is a plan view of the holding section according to the embodiment. Figure 5 is a side sectional view of the holding section according to the embodiment. Figure 6 is a view showing the arrangement of the displacement sensor and the film thickness sensor according to the embodiment.

[0085] As shown in Figure 3 , the drying processing unit 18 includes a processing vessel 31, a holding section 32, a lid 33, a lifting member 39, and a weight sensor 40.

[0086] The processing vessel 31 is a pressure vessel capable of forming a high-pressure environment of, for example, 16 to 20 MPa. The processing vessel 31 is arranged in a processing area 181 (see Figure 1 ) in which supercritical drying processing is performed. Figure 8

[0087] The holding section 32 holds the wafer W in the horizontal direction. The lid 33 supports the holding section 32. The lid 33 is connected to a not-shown moving mechanism by which the lid 33 is horizontally movable between the processing area 181 and a handoff area 182. By moving the lid 33 to the processing area 181, the holding section 32 is arranged inside the processing vessel 31, and the lid 33 blocks the opening portion 34 of the processing vessel 31.

[0088] Here, the detailed configuration of the holding section 32 will be described with reference to Figure 4 and Figure 5 . As shown in Figure 4 and Figure 5 , the holding section 32 includes a base section 32a, a plurality of support members 32b, a plurality of lifting mechanisms 32c, and a plurality of through holes 32d.

[0089] ​​The base portion 32a is a plate-shaped member disposed below the wafer W. A circular-shaped recess having a larger diameter than the wafer W is formed in the base portion 32a, and the wafer W is placed in the recess by a plurality of support members 32b to be described later.

[0090] The plurality of support members 32b are members protruding upward from the bottom surface 32a1 of the recess formed in the base portion 32a, and support the outer peripheral portion of the wafer W from below. The wafer W is supported by the plurality of support members 32b, and thereby becomes a state of being suspended from the base portion 32a (see FIG. 1). Figure 5

[0091] The plurality of lift mechanisms 32c correspond to the plurality of support members 32b one-to-one, and lift, that is, move in the vertical direction, the corresponding support members 32b. The lift mechanisms 32c can lift the support members 32b by, for example, driving force of a motor such as a motor. In addition, the lift mechanisms 32c can also lift the support members 32b using the inverse piezoelectric effect of a piezoelectric element. Further, the lift mechanisms 32c can also lift the support members 32b using air pressure.

[0092] Here, a case including four support members 32b and four lift mechanisms 32c is exemplified, but the number of sets of the support members 32b and the lift mechanisms 32c is not limited to four. In addition, here, a case where the lift mechanisms 32c are provided to all of the plurality of support members 32b is exemplified, but the holding portion 32 can also be, for example, a structure having one lift mechanism 32c that lifts one of the plurality of support members 32b. That is, the holding portion 32 can have at least one lift mechanism 32c that lifts at least one of the plurality of support members 32b.

[0093] Further, here, a case where the plurality of support members 32b are individually lifted by the plurality of lift mechanisms 32c is exemplified, but the holding portion 32 can include one lift mechanism 32c that integrally lifts the plurality of support members 32b.

[0094] The plurality of through holes 32d are formed in the bottom surface 32a1 of the recess formed in the base portion 32a, and pass through the base portion 32a in the vertical direction. The plurality of through holes 32d are formed, for example, at a radially inner side of the circular-shaped recess formed in the base portion 32a compared to the plurality of support members 32b. The plurality of through holes 32d function as flow paths of the processing fluid supplied from the bottom surface 31c (see FIG. 1) of the processing space 31a. In addition, three of the plurality of through holes 32d formed in the central portion of the above-described circular-shaped recess also function as insertion holes of lift pins 39a to be described later. The number and arrangement of the plurality of through holes 32d are not limited to the illustrated example. Figure 8 As described above, the holding portion 32 is configured to lift the wafer W in the vertical direction, and thereby the wafer W is held in a state of being suspended from the base portion 32a.

[0095] Figure 3 ​​As shown, a supply port 35A and a supply port 35B and a discharge port 36 are provided in a wall portion of the processing container 31. The supply port 35A is connected to a supply line 35C that supplies a processing fluid into the processing space. The supply port 35B is connected to a supply line 35D that supplies a processing fluid into the processing space. The discharge port 36 is connected to a discharge line 36A that discharges a processing fluid from the processing space.

[0096] The supply port 35A is connected to a side surface of the processing container 31 on a side opposite to the opening portion 34, and the supply port 35B is connected to a bottom surface of the processing container 31. Further, the discharge port 36 is connected to a lower side of the opening portion 34. Further, the number of the supply ports 35A, 35B and the discharge port 36 is not particularly limited.

[0097] A fluid supply head 37A and a fluid supply head 37B and a fluid discharge head 38 are provided in the inside of the processing container 31. The fluid supply heads 37A, 37B and the fluid discharge head 38 are each formed with a large number of openings.

[0098] The fluid supply head 37A is connected to the supply port 35A and is provided in the inside of the processing container 31 adjacent to a side surface on a side opposite to the opening portion 34. Further, the large number of openings formed in the fluid supply head 37A are directed toward the opening portion 34 side.

[0099] The fluid supply head 37B is connected to the supply port 35B and is provided in the inside of the processing container 31 at a central portion of the bottom surface. The large number of openings formed in the fluid supply head 37B are directed upward.

[0100] The fluid discharge head 38 is connected to the discharge port 36 and is provided in the inside of the processing container 31 adjacent to a side surface on the opening portion 34 side and below the opening portion 34. The large number of openings formed in the fluid discharge head 38 are directed toward the fluid supply head 37A side.

[0101] The drying processing unit 18 supplies the heated processing fluid from the fluid supply heads 37A, 37B into the inside of the processing container 31 and discharges the processing fluid in the processing container 31 through the fluid discharge head 38. Further, a damper for adjusting the discharge amount of the processing fluid from the processing container 31 is provided in a discharge passage of the processing fluid, and the discharge amount of the processing fluid is adjusted by the damper to adjust the pressure in the processing container 31 to a desired pressure. Thereby, the supercritical state of the processing fluid can be maintained in the processing container 31. Hereinafter, the processing fluid in the supercritical state is referred to as "supercritical fluid".

[0102] The IPA liquid present on the pattern formation surface (upper surface) of the wafer W is gradually dissolved in the supercritical fluid by being brought into contact with the supercritical fluid in a high pressure state (for example, 16 MPa) and is eventually replaced with the supercritical fluid. Thereby, the gaps between the patterns become a state of being filled with the supercritical fluid.

[0103] Subsequently, the drying unit 18 reduces the pressure inside the processing container 31 from a high-pressure state to atmospheric pressure. As a result, the supercritical fluid filling the gaps between the patterns changes to a normal (i.e., gaseous) processing fluid.

[0104] As described above, after replacing the IPA liquid present on the pattern forming surface with a supercritical fluid, the drying processing unit 18 removes the IPA liquid from the pattern forming surface by restoring the supercritical fluid to a gaseous processing fluid, thereby drying the pattern forming surface.

[0105] Supercritical fluids have lower viscosity than liquids (such as IPA liquid) and a higher ability to dissolve liquids. Furthermore, there is no interface between supercritical fluids and liquids or gases in equilibrium. Therefore, by performing supercritical drying, liquids can be dried without being affected by surface tension. That is, it is possible to suppress pattern collapse during the drying process.

[0106] Furthermore, in the embodiments, IPA liquid is used as the anti-drying liquid and CO2 is used as the processing fluid. However, liquids other than IPA may also be used as anti-drying liquids, and fluids other than CO2 may also be used as processing fluids.

[0107] The lifting component 39 includes a plurality of lifting pins 39a and a support body 39b that is connected to the lower end of the plurality of lifting pins 39a and supports the plurality of lifting pins 39a.

[0108] The lifting member 39 is raised and lowered by a lifting drive unit (not shown). Specifically, the lifting member 39 rises and falls between the junction position where it exchanges wafer W with the transport device 16 and the standby position. The standby position is a position below the cover 33 and the holding part 32 where it does not interfere with the cover 33 and the holding part 32.

[0109] The weight sensor 40 is, for example, a load cell. The weight sensor 40 is disposed, for example, at the lower part of the lifting member 39, and measures the weight of the wafer W supported by the lifting member 39. Specifically, the weight sensor 40 measures the weight of the wafer W after a liquid film L has been formed by the liquid processing unit 17 and before it is housed in the processing container 31.

[0110] like Figure 6 As shown, the drying unit 18 also includes a plurality of displacement sensors 43 and a plurality of film thickness sensors 45. The plurality of displacement sensors 43 and the plurality of film thickness sensors 45 are, for example, disposed in the junction region 182 (see reference). Figure 1 ), and measures are performed on the wafer W before it is sent into the processing container 31.

[0111] The plurality of displacement sensors 43 are arranged below the wafer W held by the holding section 32, and measure the distance to the lower surface of the wafer W.

[0112] The plurality of displacement sensors 43 include four displacement sensors 43 corresponding to the four support members 32b. The four displacement sensors 43 measure the distance to the lower surface of the wafer W at the periphery of the corresponding support member 32b via the through-hole 32d formed at a position closest to the corresponding support member 32b.

[0113] The plurality of film thickness sensors 45 are arranged above the wafer W held by the holding section 32, and measure the film thickness of the liquid film L formed on the wafer W.

[0114] The plurality of film thickness sensors 45 include four film thickness sensors 45 corresponding to the four support members 32b. The four film thickness sensors 45 are arranged above the corresponding support member 32b, and measure the film thickness of the liquid film L at the periphery of the corresponding support member 32b.

[0115] (4. Configuration of control device)

[0116] Next, the configuration of the control device 6 will be described with reference to Figure 7 to Fig. 6. Figure 7 is a block diagram showing the configuration of the control device 6 according to the embodiment.

[0117] As shown in Figure 7 , the control device 6 according to the embodiment includes a control section 61 and a storage section 62. The control section 61 includes an information acquisition section 61a and a lift control section 61b. Further, the storage section 62 stores scheme information 62a, liquid film change information 62b, wafer temperature information 62c, liquid amount information 62d, inclination information 62e, and film thickness distribution information 62f.

[0118] Further, the control device 6 includes, for example, a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), an input / output port, and the like, and various circuits.

[0119] The CPU of the computer functions as the information acquisition section 61a and the lift control section 61b, for example, by reading and executing a program stored in the ROM. Alternatively, at least either one of the information acquisition section 61a and the lift control section 61b or both of them can be configured by hardware such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or the like.

[0120] Further, the storage section 62 corresponds to, for example, a RAM or a HDD. The RAM or the HDD can store the recipe information 62a, the liquid film change information 62b, the wafer temperature information 62c, the liquid amount information 62d, the inclination information 62e, and the film thickness distribution information 62f.

[0121] Further, the above program can be stored in a storage medium that is readable by a computer, and can be installed from the storage medium to the storage section 62 of the control device 6. As the storage medium that is readable by a computer, there are, for example, a hard disk (HD), a flexible disk (FD), a compact disc (CD), a magneto-optical disk (MO), a memory card, and the like. Further, the control device 6 can acquire the above program and various information by using another computer connected through a wired or wireless network, a mobile storage medium, or the like.

[0122] The information acquisition section 61a is connected to the external device 47, the weight sensor 40, the plurality of displacement sensors 43, and the plurality of film thickness sensors 45, acquires various information from them, and stores the information to the storage section 62.

[0123] For example, the information acquisition section 61a can acquire the recipe information 62a from the external device 47 and store it to the storage section 62. The recipe information 62a is information indicating contents of processing to be performed by the substrate processing system 1, that is, information specifying processing conditions of the wafer W.

[0124] In the recipe information 62a, information of a liquid amount of the liquid film L formed on the wafer W in the liquid film formation processing, a kind of liquid of the liquid film L, and the like is included. Further, in the recipe information 62a, processing conditions of a flow rate of a processing fluid in the drying processing, a pressure and a temperature in the processing container 31, and the like are included. The control section 61 controls the liquid processing unit 17, the drying processing unit 18, and the like in accordance with these recipe information 62a, thereby causing the liquid processing unit 17, the drying processing unit 18, and the like to perform substrate processing such as the liquid film formation processing and the drying processing.

[0125] Further, the recipe information 62a does not always have to be acquired from the external device 47, and can be generated in the control device 6, for example.

[0126] Further, the information acquisition unit 61a can acquire liquid film change information 62b from the external device 47 and store it to the storage unit 62. The liquid film change information 62b is information indicating a change in the liquid film L over time during the drying process. The liquid film change information 62b can include information indicating a change in the liquid amount of the liquid film L over time during the drying process. Further, the liquid film change information 62b can include information indicating a change in the film thickness of the liquid film L over time during the drying process. In a case where the liquid film L has undergone coalescence during the drying process, there is a possibility that the film thickness of the liquid film L on which coalescence has occurred is greater than the initial film thickness. The liquid film change information 62b can include information of a change in the film thickness of the liquid film L over time due to coalescence.

[0127] Further, the information acquisition unit 61a can acquire wafer temperature information 62c from the external device 47 and store it to the storage unit 62. The wafer temperature information 62c is information indicating the temperature of the wafer W during the drying process. Further, the liquid film change information 62b and the wafer temperature information 62c can be obtained through a prior experiment, simulation.

[0128] Further, the information acquisition unit 61a acquires the weight of the wafer W after the liquid film formation process from the weight sensor 40. Further, the information acquisition unit 61a calculates a difference between the obtained weight of the wafer W after the liquid film formation process and the weight of the wafer W before the liquid film formation process obtained in advance, and based on the calculated difference, calculates the liquid amount of the liquid film L formed on the wafer W. The information acquisition unit 61a stores the calculated liquid amount of the liquid film L as liquid amount information 62d to the storage unit 62.

[0129] Further, the information acquisition unit 61a acquires information of distances from the plurality of displacement sensors 43 to the lower surface of the wafer W, and based on the obtained information, calculates the tilt condition of the wafer W. Then, the information acquisition unit 61a stores the calculated tilt condition of the wafer W as tilt information 62e to the storage unit 62.

[0130] Further, the information acquisition unit 61a acquires information of the film thickness of the liquid film L from the plurality of film thickness sensors 45, and based on the obtained information, generates a film thickness distribution of the liquid film L on the wafer W. Then, the information acquisition unit 61a stores the generated film thickness distribution of the liquid film L as film thickness distribution information 62f to the storage unit 62.

[0131] The lift control unit 61b controls the plurality of lift mechanisms 32c possessed by the holding unit 32 based on various information stored in the storage unit 62, thereby causing the plurality of support members 32b to be lifted as a whole or individually.

[0132] (5. Flow of supercritical fluid)

[0133] Next, the flow of the supercritical fluid in the processing container 31 will be described with reference to Figure 8 Figure 8 ​is a view showing an example of the flow of the supercritical fluid in the processing space.

[0134] As shown in Figure 8 , the holding portion 32 is disposed in the processing space 31a of the processing container 31 at a height position not in contact with the top surface 31b and the bottom surface 31c of the processing space 31a. In addition, the wafer W supported by the plurality of support members 32b is disposed at a height position not in contact with the top surface 31b of the processing space 31a and the bottom surface 32al of the base portion 32a.

[0135] A laminar flow of the supercritical fluid is formed inside the processing container 31. The laminar flow of the supercritical fluid, for example, is supplied into the processing space 31a from the fluid supply head 37B (refer to Figure 3 ), and flows in the negative direction of the X axis between the lower surface 32a2 of the base portion 32a and the bottom surface 31c of the processing space 31a. Thereafter, the laminar flow of the supercritical fluid reaches the peripheral portion of the wafer W by passing through the through hole 32d to the lower surface of the wafer W, and flows in the negative direction of the X axis between the lower surface of the wafer W and the bottom surface 32al of the base portion 32a. Thereafter, the laminar flow of the supercritical fluid enters the upper surface side of the wafer W, and flows in the positive direction of the X axis between the top surface 31b of the processing container 31 and the upper surface of the liquid film L formed on the wafer W.

[0136] As described above, the laminar flow of the supercritical fluid flows between the lower surface of the wafer W and the bottom surface 32al of the base portion 32a, and between the top surface 31b of the processing container 31 and the upper surface of the liquid film L. Here, the initial value of the distance between the lower surface of the wafer W and the bottom surface 32al of the base portion 32a, that is, the protruding amount of the support member 32b will be "HL". In addition, the initial value of the distance between the top surface 31b of the processing container 31 and the upper surface of the wafer W will be "HU".

[0137] (6. Lift control processing)

[0138] Next, an example of the lift control processing performed by the lift control portion 61b will be described with reference to Figures 9-15 . First, an example of the lift control processing using the recipe information 62a or the liquid amount information 62d will be described with reference to Figure 9 . Figure 9 is a view showing an example of the lift control processing using the recipe information 62a or the liquid amount information 62d.

[0139] As shown in Figure 9As shown, the lift control section 61b can acquire the liquid amount of the liquid film L before the drying process from the scheme information 62a or the liquid amount information 62d stored in the storage section 62. The lift control section 61b controls the plurality of lift mechanisms 32c to lift the plurality of support members 32b integrally so that the height position of the wafer W in the processing space 31a becomes a height position corresponding to the liquid amount of the liquid film L before the drying process.

[0140] Here, the "height position corresponding to the liquid amount of the liquid film L before the drying process" means that the distance G between the upper surface of the liquid film L before the drying process and the top surface 31b of the processing space 31a is always a certain height position of the wafer W regardless of the liquid amount of the liquid film L.

[0141] For example, in a case where the liquid amount before the drying process is Xa, the lift control section 61b lowers the height of the plurality of support members 32b compared to a case where the liquid amount before the drying process is Xb which is less than Xa. Thereby, it is possible to make the size of the gap between the top surface 31b of the processing space 31a which is the flow path of the supercritical fluid and the upper surface of the liquid film L constant regardless of the liquid amount of the liquid film L before the drying process. That is, it is possible to make the flow rate and the flow velocity of the supercritical fluid flowing in the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L constant regardless of the liquid amount of the liquid film L before the drying process.

[0142] As described above, the lift control section 61b can also raise or lower the plurality of support members 32b depending on the liquid amount of the liquid film. Thereby, for example, it is possible to set the size of the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L with high precision so that the flow rate and the flow velocity of the supercritical fluid flowing on the upper surface of the liquid film L become a flow rate and a flow velocity suitable for the drying process.

[0143] Further, the control device 6 can also store, in advance, correlation information indicating the correlation between the liquid amount of the liquid film L and the height of the plurality of support members 32b to the storage section 62. In this case, the lift control section 61b can control the plurality of lift mechanisms 32c to raise or lower the plurality of support members 32b in accordance with the above-mentioned correlation information stored in the storage section 62.

[0144] In addition, the lift control section 61b can perform the same lift control process as described above using the film thickness distribution information 62f stored in the storage section 62. That is, the lift control section 61b can control the plurality of lift mechanisms 32c to lift the plurality of support members 32b integrally so that the height position of the wafer W in the processing space 31a becomes a height position corresponding to the film thickness of the liquid film L before the drying process. As described above, the lift control section 61b can also raise or lower the plurality of support members 32b depending on the film thickness of the liquid film L.

[0145] Next, referring to Figure 10 andFigure 11 An example of the lift control process using the liquid film change information 62b will be described. Figure 10 is a graph showing an example in which the support member 32b is lifted in accordance with the change in the liquid amount of the liquid film L during the drying process. Figure 11 is a graph showing an example in which the support member 32b is lowered in accordance with the change in the liquid amount of the liquid film L during the drying process.

[0146] During the drying process, the liquid amount of the liquid film L decreases with the passage of time. Therefore, the gap between the top surface 31b of the flow path of the supercritical fluid, i.e., the processing space 31a, and the upper surface of the liquid film L gradually becomes larger as the liquid amount of the liquid film L decreases. As a result, the flow rate and the flow velocity of the supercritical fluid flowing along the upper surface of the liquid film L change with the passage of time.

[0147] Therefore, the lift control section 61b can also lift the plurality of support members 32b during the drying process in accordance with the change in the liquid amount of the liquid film L during the drying process, based on the liquid film change information 62b. Specifically, as shown in Figure 10 the lift control section 61b lifts the plurality of support members 32b during the drying process so that the size (distance G) of the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L during the drying process becomes constant.

[0148] Thus, the size of the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L can be made constant regardless of the change in the liquid amount of the liquid film L during the drying process. That is, the flow rate and the flow velocity of the supercritical fluid flowing in the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L can be made constant regardless of the change in the liquid amount of the liquid film L during the drying process.

[0149] As described above, the lift control section 61b can also lift the plurality of support members 32b during the drying process in accordance with the liquid amount of the liquid film L during the drying process. Thus, for example, the size of the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L during the drying process can be continuously maintained so that the flow rate and the flow velocity of the supercritical fluid flowing along the upper surface of the liquid film L become the flow rate and the flow velocity suitable for the drying process.

[0150] Further, the lift control section 61b can also lift the plurality of support members 32b during the drying process in accordance with the change in the film thickness of the liquid film L during the drying process, based on the liquid film change information 62b.

[0151] In addition, as shown in Figure 11As shown, during the drying process, due to the aggregation of the IPA liquid constituting the liquid film L, there is a possibility that the thickness of the liquid film L may become greater than the thickness before the drying process begins. In such a case, since the aggregated liquid film L comes into contact with the top surface 31b of the processing space 31a, there is a possibility that the particle count of the wafer W after the drying process may increase.

[0152] Therefore, the lifting control unit 61b can also lower multiple support members 32b during the drying process based on the liquid film change information 62b and the changing thickness of the liquid film L during the drying process. Specifically, the lifting control unit 61b lowers multiple support members 32b so that the distance HU between the top surface 31b of the processing space 31a and the upper surface of the wafer W becomes greater than the thickness of the condensed liquid film L.

[0153] Therefore, it is possible to prevent the condensed liquid film L from contacting the top surface 31b of the processing space 31a. Thus, it is possible to suppress the increase in particle count of the wafer W after the drying process.

[0154] Next, refer to Figure 12 and Figure 13 An example of lifting control processing using chip temperature information 62c is explained. Figure 12 This is a diagram showing an example of the height position of wafer W during the drying process. Figure 13 This diagram illustrates an example of changing the height position of wafer W based on wafer temperature information 62c.

[0155] like Figure 12 As shown, during the drying process, there is a possibility that the wafer W may be heated to a temperature higher than desired due to radiant heat from the metal-based base portion 32a.

[0156] Therefore, the lifting control unit 61b can control multiple lifting mechanisms 32c to raise or lower multiple support components 32b based on the wafer temperature information 62c, so that the temperature of the wafer W in the drying process is not too high compared to the desired temperature.

[0157] For example, the lifting control unit 61b determines whether the difference between the temperature of the wafer W (e.g., X0°C) indicated by the wafer temperature information 62c and the desired temperature (e.g., the processing temperature indicated by the scheme information 62a) exceeds the normal range. Then, if the difference exceeds the normal range, the lifting control unit 61b raises or lowers multiple support members 32b to change the height position of the wafer W before the drying process begins. For example, if the difference between X0°C and the processing temperature is higher than the normal range, the lifting control unit 61b... Figure 13As illustrated, the plurality of support members 32b are raised, thereby increasing the gap between the lower surface of the wafer W and the bottom surface 32al of the base portion 32a. Thereby, it is possible to suppress the influence of the radiant heat received by the wafer W from the base portion 32a. As a result, it is possible to lower the temperature of the wafer W during the drying process to X1°C, which is lower than X0°C, i.e., close to the desired temperature.

[0158] As described above, the plurality of support members 32b can also be raised or lowered by the lift control portion 61b based on the wafer temperature information indicating the temperature of the wafer W during the drying process. Thereby, it is possible to make the temperature of the wafer W during the drying process close to the desired temperature, so it is possible to suppress the collapse of the pattern formed on the upper surface of the wafer W.

[0159] Next, an example of the lift control process using the inclination information 62e will be described with reference to Figure 14 and Figure 15 . Figure 14 is a diagram indicating an example of a case where the wafer W supported by the plurality of support members 32b is inclined. Figure 15 is a diagram indicating an example of a case where the wafer W is eliminated of the inclination by the lift control process.

[0160] When the wafer W supported by the plurality of support members 32b is warped or inclined, the in-plane uniformity of the film thickness of the liquid film L deteriorates, and the performance of the drying process can be lowered. For example, Figure 14 indicates a case where the film thickness of the liquid film L around the support member 32b4 among the plurality of support members 32b1 to 32b4 becomes larger than other portions.

[0161] In such a case, the lift control portion 61b can raise or lower the plurality of support members 32b1 to 32b4 individually based on the inclination information 62e to eliminate the warping or inclination of the wafer W. For example, in the case illustrated in Figure 14 , the inclination of the wafer W can be eliminated by raising the support member 32b4. Thereby, as illustrated in Figure 15 , since the film thickness uniformity of the liquid film L can be improved, it is possible to suppress the collapse of the pattern formed on the upper surface of the wafer W.

[0162] (7. Modified Example)

[0163] In the above-described embodiment, an example of a case where the plurality of film thickness sensors 45 are arranged in the handover region 182 (refer to Figure 1 ) is described, but the plurality of film thickness sensors 45 can also be arranged in the processing region 181. Figure 16 is a diagram indicating the arrangement of the film thickness sensor 45 of the modified example.

[0164] For example, as illustrated in Figure 16As shown, a plurality of film thickness sensors 45 can also be arranged above the processing container 31, and the film thickness of the liquid film L formed on the upper surface of the wafer W arranged in the processing space 31a is measured through the plurality of transparent portions 31d provided in the processing container 31. By being configured as described above, the plurality of support members 32b can be raised or lowered during the drying process in accordance with the film thickness of the liquid film L actually measured during the drying process.

[0165] Further, in the embodiment described above, the example in which the weight sensor 40, the displacement sensor 43, and the film thickness sensor 45 are provided in the drying processing unit 18 is described, but these sensors do not necessarily need to be provided in the drying processing unit 18. For example, the substrate processing system 1 can include an inspection unit having at least one of the weight sensor 40, the displacement sensor 43, and the film thickness sensor 45. Figure 16

[0166] Further, in the embodiment described above, the example in which the weight sensor 40, the displacement sensor 43, and the film thickness sensor 45 are provided in the drying processing unit 18 is described, but these sensors do not necessarily need to be provided in the drying processing unit 18. For example, the substrate processing system 1 can include an inspection unit having at least one of the weight sensor 40, the displacement sensor 43, and the film thickness sensor 45.

[0167] As described above, the substrate processing apparatus (as an example, the drying processing unit 18) of the embodiment is a substrate processing apparatus that performs a drying process of drying a substrate (as an example, the wafer W) on which a liquid film (as an example, the liquid film L) is formed on a pattern formation surface using a processing fluid in a supercritical state, and includes a processing container (as an example, the processing container 31), a holding portion (as an example, the holding portion 32), and a supply portion (as an example, the fluid supply heads 37A, 37B). The processing container can accommodate the substrate. The holding portion can hold the substrate in the processing container. The supply portion can supply the processing fluid to the processing container. Further, the holding portion includes a base portion (as an example, the base portion 32a), a plurality of support members (as an example, the plurality of support members 32b), and a lifting mechanism (as an example, the plurality of lifting mechanisms 32c). The base portion is arranged below the substrate. The plurality of support members are provided on the base portion and can support the substrate from below. The lifting mechanism can raise and lower the plurality of support members.

[0168] As described above, by being configured to be able to raise and lower the plurality of support members that support the substrate, for example, the processing conditions such as the flow rate and the flow velocity of the supercritical fluid, which depend on the length of the support member, can be controlled with high precision and easily. Therefore, the collapse of the pattern formed on the upper surface of the substrate can be suppressed. Further, for example, compared to a case in which the length of the support member is changed by replacing the support member with one having a different length, the replacement work is not required.

[0169] ​Further, the substrate processing apparatus of the embodiment can further include a lift control section (as an example, the lift control section 61b) that controls the lift mechanism. In this case, the lift control section causes the plurality of support members to be lifted or lowered in accordance with the liquid amount or film thickness of the liquid film.

[0170] Further, the substrate processing apparatus of the embodiment can further include an acquisition section (as an example, the information acquisition section 61a) that acquires the liquid amount or film thickness of the liquid film formed on the substrate before the substrate is housed in the processing container. In this case, the lift control section can cause the plurality of support members to be lifted or lowered in accordance with the liquid amount or film thickness acquired by the acquisition section.

[0171] Thereby, for example, the size of the gap between the top surface of the processing container and the upper surface of the liquid film can be set with high precision so that the flow rate and flow velocity of the supercritical fluid flowing on the upper surface of the liquid film become a flow rate and flow velocity suitable for the drying process.

[0172] Further, the substrate processing apparatus of the embodiment can further include an acquisition section (as an example, the information acquisition section 61a) that acquires liquid film change information indicating a change in the liquid amount or film thickness of the liquid film over time in the drying process. In this case, the lift control section can cause the plurality of support members to be lifted or lowered in accordance with the liquid amount or film thickness that changes in the drying process, based on the liquid film change information acquired by the acquisition section.

[0173] Thereby, for example, the size of the gap between the top surface of the processing container and the upper surface of the liquid film can be continuously maintained in the drying process, the size of the gap being such that the flow rate and flow velocity of the supercritical fluid flowing on the upper surface of the liquid film become a flow rate and flow velocity suitable for the drying process.

[0174] Further, the substrate processing apparatus of the embodiment can further include a lift control section (as an example, the lift control section 61b) and an acquisition section (as an example, the information acquisition section 61a). The lift control section can control the lift mechanism. The acquisition section can acquire the inclination of the substrate supported by the plurality of support members. Further, the lift mechanism can individually lift and lower the plurality of support members. In this case, the lift control section can individually lift or lower the plurality of support members in accordance with the inclination of the substrate acquired by the acquisition section.

[0175] By individually lifting or lowering the plurality of support members to eliminate the inclination of the substrate, the film thickness uniformity of the liquid film can be improved, and collapse of a pattern formed on the upper surface of the substrate can be suppressed.

[0176] The lift control section can also raise or lower the plurality of support members in accordance with the liquid amount or film thickness of the liquid film, so that the distance between the upper surface of the liquid film and the top surface (as an example, the top surface 31b) in the processing container (as an example, the processing space 31a) becomes constant. By making the size of the gap between the flow path of the supercritical fluid, that is, the upper surface of the liquid film, and the top surface in the processing container constant, the flow rate and flow velocity of the supercritical fluid can be made constant regardless of the liquid amount of the liquid film.

[0177] The acquisition section can be at least one of a film thickness sensor (as an example, the film thickness sensor 45), an image sensor, a weight sensor (as an example, the weight sensor 40), and a displacement sensor (as an example, the displacement sensor 43). Thereby, the liquid amount or film thickness of the liquid film can be acquired.

[0178] Furthermore, the embodiments disclosed in the present application are illustrative in all aspects and should not be considered as limiting. In fact, the above-described embodiments can be embodied in various ways. Furthermore, the above-described embodiments can be omitted, replaced, changed in various ways as long as they do not depart from the scope of the appended claims and the idea thereof.

Claims

1. A substrate processing apparatus capable of performing a drying process of drying a substrate having a liquid film formed on a pattern formation surface using a processing fluid in a supercritical state, the substrate processing apparatus characterized by comprising: a processing container that accommodates the substrate; a holding section that holds the substrate in the processing container; and a supply section that supplies the processing fluid into the processing container, the holding section including: a base section disposed below the substrate; a plurality of support members provided on the base section and capable of supporting the substrate from below; a lifting mechanism that lifts the plurality of support members; and a lifting control section that controls the lifting mechanism, the lifting control section lifting or lowering the plurality of support members in accordance with a liquid amount or a film thickness of the liquid film.

2. The substrate processing apparatus according to claim 1, further comprising: an acquisition section that acquires the liquid amount or the film thickness of the liquid film formed on the substrate before the substrate is accommodated into the processing container, the lifting control section lifting or lowering the plurality of support members in accordance with the liquid amount or the film thickness acquired by the acquisition section.

3. The substrate processing apparatus according to claim 1, further comprising: an acquisition section that acquires liquid film change information indicating a change in the liquid amount or the film thickness of the liquid film over time in the drying process, the lifting control section lifting or lowering the plurality of support members in accordance with the liquid amount or the film thickness that changes in the drying process, based on the liquid film change information acquired by the acquisition section.

4. The substrate processing apparatus according to claim 1, further comprising: a lifting control section that controls the lifting mechanism; and an acquisition section that acquires a tilt condition of the substrate supported by the plurality of support members, the lifting mechanism being capable of individually lifting the plurality of support members, the lifting control section individually lifting or lowering the plurality of support members in accordance with the tilt condition of the substrate acquired by the acquisition section.

5. The substrate processing apparatus according to any one of claims 1 to 3, wherein the lifting control section lifts or lowers the plurality of support members in accordance with the liquid amount or the film thickness of the liquid film so that a distance from an upper surface of the liquid film to a top surface in the processing container becomes a certain distance.

6. The substrate processing apparatus according to any one of claims 2 to 4, wherein the acquisition section is at least one of a film thickness sensor, an image sensor, a weight sensor, and a displacement sensor.

7. A substrate drying method of drying a substrate having a liquid film formed on a pattern formation surface using a processing fluid in a supercritical state, the substrate drying method characterized by comprising: a step of holding the substrate in a processing container using a holding section that holds the substrate, the holding section having: a base section disposed below the substrate; and a plurality of support members provided on the base section and capable of supporting the substrate from below; a step of supplying the processing fluid into the processing container; and a step of lifting or lowering at least one of the plurality of support members included in the holding section in accordance with a state of the liquid film. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. The substrate processing apparatus of claim 1, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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