Substrate processing apparatus and substrate drying method

Abstract

The invention provides a substrate processing apparatus and a substrate drying method. A substrate processing apparatus according to the present invention is capable of performing a drying process for drying a substrate on which a liquid film is formed on a pattern formation surface using a processing fluid in a supercritical state. The substrate processing apparatus includes a processing container, a holding unit, and a supply unit. The processing container accommodates a substrate. The holding unit holds the substrate in the processing container. The supply unit supplies a processing fluid into the processing container. 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 can support the substrate from below. The lifting mechanism lifts the plurality of support members. The present invention can suppress the collapse of a pattern formed on the upper surface of a substrate in a technique for drying the substrate using a treatment fluid in a supercritical state.

Description

Technical Field

[0001] This invention relates to a substrate processing apparatus and a substrate drying method. Background Technology

[0002] A known technique involves drying a substrate, such as a semiconductor wafer, by bringing the substrate with its surface wetted by the liquid into contact with a supercritical processing fluid during the drying process following the application of a liquid to the upper surface of the substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-251550 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The purpose of this invention is to provide a technique for suppressing pattern collapse formed on the upper surface of a substrate in a process of drying a substrate using a supercritical fluid.

[0008] Technical solutions for solving technical problems

[0009] One aspect of the substrate processing apparatus of the present invention enables a drying process in which a substrate on which a liquid film is formed on a patterning surface is dried using a supercritical processing fluid. The substrate processing apparatus includes a processing container, a holding section, and a supply section. The processing container houses the substrate. The holding section holds the substrate within the processing container. The supply section supplies processing fluid into the processing container. Furthermore, the holding section includes a base section, multiple support members, and a lifting mechanism. The base section is disposed below the substrate. The multiple support members are provided on the base section and are capable of supporting the substrate from below. The lifting mechanism raises and lowers the multiple support members.

[0010] Invention Effects

[0011] According to the present invention, in the technique of drying a substrate using a supercritical processing fluid, it is possible to suppress the collapse of patterns formed on the upper surface of the substrate. Attached Figure Description

[0012] Figure 1 This is a diagram showing the configuration of the substrate processing system in the implementation method.

[0013] Figure 2 This is a diagram showing the configuration of the liquid processing unit in the embodiment.

[0014] Figure 3 This is a perspective view of the drying unit in the embodiment.

[0015] Figure 4 This is a top view of the retaining part in the embodiment.

[0016] Figure 5 This is a side cross-sectional view of the retaining part in the embodiment.

[0017] Figure 6 This is a diagram showing the configuration of the displacement sensor and film thickness sensor in the implementation method.

[0018] Figure 7 This is a block diagram illustrating the configuration of the control device in the implementation method.

[0019] Figure 8 This is a diagram illustrating an example of supercritical fluid flow within a processing space.

[0020] Figure 9 This diagram illustrates an example of lifting control processing that uses scheme information or liquid volume information.

[0021] Figure 10 This diagram illustrates an example of a support component rising due to changes in the liquid volume of the liquid film during the drying process.

[0022] Figure 11 This diagram illustrates an example of how the support component descends due to changes in the liquid volume of the liquid film during the drying process.

[0023] Figure 12 This is a diagram showing an example of the height position of a wafer during the drying process.

[0024] Figure 13 This diagram illustrates an example of how the height position of a wafer can be changed based on wafer temperature information.

[0025] Figure 14 This diagram illustrates an example of a wafer supported by multiple support components tilting.

[0026] Figure 15 This diagram illustrates an example of a situation where tilted wafers are eliminated through lift control processing.

[0027] Figure 16 This is a diagram showing the configuration of the film thickness sensor in a modified example.

[0028] Explanation of reference numerals in the attached figures

[0029] W chip

[0030] 1. Substrate Processing System

[0031] 2. Sending in and sending out of stations

[0032] 3 processing stations

[0033] 5 processing blocks

[0034] 17 Liquid Treatment Unit

[0035] 18 drying processing units

[0036] 19 supply units

[0037] 31 Processing Container

[0038] 32 Maintenance Section

[0039] 32a base section

[0040] 32b Support component

[0041] 32c lifting mechanism

[0042] 32d through hole

[0043] 33 Cover

[0044] 39 lifting components

[0045] 40 weight sensors

[0046] 61 Control Department

[0047] 61a Information Acquisition Department

[0048] 61b Lifting Control Unit

[0049] 62 Storage Unit

[0050] 62a scheme information

[0051] 62b Liquid Film Change Information

[0052] 62c chip temperature information

[0053] 62d liquid volume information

[0054] 62e tilt information

[0055] 62f film thickness distribution information. Detailed Implementation

[0056] Hereinafter, with reference to the accompanying drawings, embodiments (hereinafter referred to as "Embodiments") for carrying out the substrate processing apparatus and substrate drying method of the present invention will be described in detail. However, the substrate processing apparatus and substrate drying method of the present invention are not limited to these embodiments. Furthermore, the embodiments can be appropriately combined without contradicting the processing content. In the following embodiments, the same reference numerals are used to label the same parts, and repeated descriptions are omitted.

[0057] In addition, in the figures referred to below, to facilitate understanding, the X-axis, Y-axis, and Z-axis directions are sometimes shown as mutually orthogonal, with the positive Z-axis direction as the vertically upward orthogonal coordinate system. Furthermore, the direction of rotation with the vertical axis as the center of rotation is sometimes referred to as the θ direction.

[0058] Furthermore, in the embodiments shown below, descriptions such as "certain," "orthogonal," "perpendicular," or "parallel" are sometimes used, but these descriptions do not need to be strictly "certain," "orthogonal," "perpendicular," or "parallel." That is, the above descriptions allow for errors in manufacturing precision, setting precision, etc.

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

[0060] First, refer to Figure 1 The configuration of the substrate processing system in the implementation method will be described. Figure 1 This is a diagram showing the configuration of the substrate processing system in the implementation method.

[0061] like Figure 1 As shown, the substrate processing system 1 includes an infeed / outfeed station 2 and a processing station 3. The infeed / outfeed station 2 and the processing station 3 are arranged adjacent to each other.

[0062] The infeed / outfeed station 2 includes a carrier placement section 11 and a transport section 12. The carrier placement section 11 holds multiple carriers C that hold multiple semiconductor wafers (hereinafter referred to as "wafers W") in a horizontal position.

[0063] The conveying section 12 is disposed adjacent to the carrier placement section 11. The conveying device 13 and the transfer section 14 are disposed inside the conveying section 12.

[0064] The transport device 13 includes a wafer holding mechanism for holding the wafer W. Furthermore, the transport device 13 is movable in both the horizontal and vertical directions and can rotate about a vertical axis, and can use the wafer holding mechanism to transport the wafer W between the carrier C and the junction 14.

[0065] The processing station 3 is located adjacent to the conveying unit 12. The processing station 3 includes the conveying unit 15 and multiple processing blocks 16.

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

[0067] The transport device 16 includes a wafer holding mechanism for holding the wafer W. Furthermore, the transport device 16 is movable in both the horizontal and vertical directions and can rotate about a vertical axis, and can use the wafer holding mechanism to transport the wafer W between the junction 14 and multiple processing blocks 5.

[0068] Multiple processing blocks 5 are arranged adjacent to the conveying area 15 on both sides of the conveying area 15. Specifically, the multiple processing blocks 5 are arranged on one side (positive Y-axis side) and the other side (negative Y-axis side) of the conveying area 15 in a direction orthogonal to the direction (X-axis direction) of the parallel arrangement of the inlet / outlet station 2 and the processing station 3.

[0069] Each processing block 5 includes a liquid processing unit 17, a drying processing unit 18, and a supply unit 19.

[0070] The liquid processing unit 17 performs a cleaning process on the patterned surface, i.e., the upper surface, of the wafer W. Furthermore, the liquid processing unit 17 performs a liquid film formation process to form a liquid film on the upper surface of the cleaned wafer W. The configuration of the liquid processing unit 17 will be described later.

[0071] The drying unit 18 performs supercritical drying on the wafer W after the liquid film formation process. Specifically, the drying unit 18 dries the wafer W by contacting it with a supercritical processing fluid.

[0072] The drying unit 18 includes a processing region 181 for supercritical drying and a transfer region 182 for transferring the wafer W between the transport block 4 and the processing region 181. The processing region 181 and the transfer region 182 are arranged along the transport region 15. The specific configuration of the drying unit 18 will be described later.

[0073] The supply unit 19 supplies processing fluid to the drying unit 18. Specifically, the supply unit 19 includes a supply device assembly including a flow meter, a flow regulator, a back pressure valve, a heater, etc., and a housing for housing the supply device assembly. In this embodiment, the supply unit 19 supplies CO2, which is the processing fluid, to the drying unit 18.

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

[0075] (2. Composition of the liquid treatment unit)

[0076] Next, refer to Figure 2 The configuration of the liquid treatment unit 17 will be explained. Figure 2This diagram illustrates the configuration of the liquid processing unit 17 in the embodiment. The liquid processing unit 17 is configured, for example, as a monolithic cleaning apparatus that cleans wafer W one by one by rotating the cleaning process.

[0077] like Figure 2 As shown, the liquid treatment unit 17 holds the wafer W approximately horizontally via a wafer holding mechanism 25 disposed within the outer chamber 23 forming the processing space, and rotates the wafer W by rotating the wafer holding mechanism 25 about a vertical axis. Then, the liquid treatment unit 17 moves the nozzle arm 26 above the rotating wafer W and supplies liquid medicine and rinsing liquid from the liquid medicine nozzle 26a disposed at the front end of the nozzle arm 26 in a predetermined sequence, thereby performing cleaning treatment on the upper surface of the wafer W.

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

[0079] The cleaning process begins with the use of SC1 solution (a mixture of ammonia and hydrogen peroxide aqueous solution) as an alkaline solution to remove particulate and organic contaminants. This is followed by rinsing with deionized water (DIW). Next, a dilute hydrofluoric acid aqueous solution (DHF) as an acidic solution is used to remove the natural oxide film, followed by rinsing with DIW.

[0080] The aforementioned liquid medicines are received by the outer chamber 23 and the inner cup 24 disposed within the outer chamber 23, and discharged from the drain port 23a at the bottom of the outer chamber 23 and the drain port 24a at the bottom of the inner cup 24. Furthermore, the atmosphere within the outer chamber 23 is vented from the vent port 23b 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 treatment unit 17 supplies IPA liquid to the upper and lower surfaces of the wafer W while rotating the wafer holding mechanism 25. As a result, the DIW remaining on both sides of the wafer W is replaced with IPA. Afterward, the liquid treatment unit 17 slowly stops the rotation of the wafer holding mechanism 25.

[0082] After the liquid film formation process is completed, the wafer W, with an IPA liquid film formed on its upper surface, is transferred to the transport device 16 via a transfer mechanism (not shown) provided in the wafer holding mechanism 25, and is then 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 process of transporting the wafer W from the liquid processing unit 17 to the drying processing unit 18 and during the feeding operation into the drying processing unit 18.

[0083] (3. Composition of the drying unit)

[0084] Next, refer to Figures 3-6 The configuration of the drying unit 18 will be explained. Figure 3 This is a perspective view of the drying unit 18 of the embodiment. Figure 4 This is a top view of the retaining part in the embodiment. Figure 5 This is a side cross-sectional view of the retaining part in the embodiment. Figure 6 This is a diagram showing the configuration of the displacement sensor and film thickness sensor in the implementation method.

[0085] like Figure 3 As shown, the drying unit 18 includes a processing container 31, a holding part 32, a cover 33, a lifting part 39, and a weight sensor 40.

[0086] The processing vessel 31 is a pressure vessel capable of creating a high-pressure environment, for example, 16 to 20 MPa. The processing vessel 31 is disposed in the processing area 181 (see reference). Figure 1 Supercritical drying is performed in the internal space of the processing container 31, i.e., processing space 31a (see reference). Figure 8 It will be carried out in ).

[0087] The holding part 32 holds the wafer W in the horizontal direction. The cover 33 supports the holding part 32. The cover 33 is connected to a moving mechanism (not shown), which allows it to move horizontally between the processing area 181 and the junction area 182. By moving the cover 33 toward the processing area 181, the holding part 32 is positioned inside the processing container 31, and the cover 33 blocks the opening 34 of the processing container 31.

[0088] Here, refer to Figure 4 and Figure 5 The specific structure of the retaining part 32 will be explained. For example... Figure 4 and Figure 5 As shown, the holding part 32 includes a base part 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 component disposed below the wafer W. A circular recess with a diameter larger than that of 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 described later.

[0090] Multiple support members 32b protrude upward from the bottom surface 32a1 of the recess formed in the base portion 32a, supporting the outer periphery of the wafer W from below. The wafer W is supported by the multiple support members 32b, thus becoming suspended in the base portion 32a (see reference). Figure 5 ).

[0091] Multiple lifting mechanisms 32c correspond one-to-one with multiple support components 32b, causing the corresponding support components 32b to rise or fall, i.e., move in the vertical direction. The lifting mechanisms 32c can, for example, use the driving force of an electric motor such as a motor to raise or lower the support components 32b. Alternatively, the lifting mechanisms 32c can also utilize the inverse piezoelectric effect of a piezoelectric element to raise or lower the support components 32b. Furthermore, the lifting mechanisms 32c can also utilize air pressure to raise or lower the support components 32b.

[0092] This example illustrates a configuration including four support members 32b and four lifting mechanisms 32c; however, the number of sets of support members 32b and lifting mechanisms 32c is not limited to four. Furthermore, this example illustrates a configuration where lifting mechanisms 32c are provided for multiple support members 32b; however, the holding part 32 may also have a structure having, for example, a single lifting mechanism 32c that raises or lowers one of the multiple support members 32b. That is, the holding part 32 may have at least one lifting mechanism 32c that raises or lowers at least one of the multiple support members 32b.

[0093] In addition, this example illustrates the case where multiple support members 32b are raised and lowered individually by multiple lifting mechanisms 32c. However, the holding part 32 may also include a single lifting mechanism 32c that raises and lowers multiple support members 32b as a whole.

[0094] Multiple through holes 32d are formed on the bottom surface 32a1 of the recess formed in the base portion 32a, and penetrate the base portion 32a in the vertical direction. For example, the multiple through holes 32d are formed on the radially inner side of the circular recess formed in the base portion 32a compared to the multiple support members 32b. The multiple through holes 32d serve as a connection from the bottom surface 31c of the processing space 31a (see reference). Figure 8 The flow path for the supplied processing fluid also functions as a channel. Furthermore, the three through holes 32d formed in the central portion of the circular recess also function as insertion holes for the lifting pin 39a, which will be described later. The number and arrangement of the through holes 32d are not limited to the example shown.

[0095] like Figure 3As shown, supply ports 35A and 35B and a discharge port 36 are provided on the wall of the processing container 31. Supply port 35A is connected to supply line 35C for supplying processing fluid to the processing space. Supply port 35B is connected to supply line 35D for supplying processing fluid to the processing space. Discharge port 36 is connected to discharge line 36A for discharging processing fluid from the processing space.

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

[0097] The processing container 31 is provided with fluid supply heads 37A and 37B and fluid discharge head 38. All fluid supply heads 37A and 37B and fluid discharge head 38 are formed with a large number of openings.

[0098] The fluid supply head 37A is connected to the supply port 35A and is disposed inside the processing container 31, adjacent to the side opposite to the opening 34. Furthermore, a large number of openings are formed in the fluid supply head 37A facing the opening 34.

[0099] The fluid supply head 37B is connected to the supply port 35B and is located in the center of the bottom surface inside the processing container 31. Numerous openings formed in the fluid supply head 37B face upwards.

[0100] The fluid discharge head 38 is connected to the discharge port 36 and is located inside the processing container 31, adjacent to the side of the opening 34, and positioned below the opening 34. Numerous openings are formed in the fluid discharge head 38 facing the fluid supply head 37A.

[0101] The drying unit 18 supplies heated processing fluid into the processing container 31 from fluid supply heads 37A and 37B, and discharges the processing fluid from the processing container 31 through the fluid discharge head 38. Furthermore, a damper is provided in the discharge passage of the processing fluid to adjust the discharge rate from the processing container 31, thereby regulating the pressure inside the processing container 31 to the desired pressure. This allows the processing fluid to maintain a supercritical state within the processing container 31. Hereinafter, the supercritical processing fluid will be referred to as "supercritical fluid".

[0102] The IPA liquid present on the patterning surface (upper surface) of wafer W is gradually dissolved in the supercritical fluid by contacting it under high pressure (e.g., 16 MPa), and is eventually replaced by the supercritical fluid. As a result, the gaps between the patterns are 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 taken on the wafer W before it is sent into the processing container 31.

[0111] Multiple displacement sensors 43 are arranged below the wafer W held by the holding part 32 to measure the distance up to the lower surface of the wafer W.

[0112] The plurality of displacement sensors 43 includes four displacement sensors 43 corresponding to 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 through through holes 32d formed at the position closest to the corresponding support member 32b.

[0113] Multiple film thickness sensors 45 are disposed above the wafer W held by the holding part 32 to measure the film thickness of the liquid film L formed on the wafer W.

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

[0115] (4. Composition of the control device)

[0116] Next, refer to Figure 7 The configuration of control device 6 will be explained. Figure 7 This is a block diagram illustrating the configuration of the control device 6 in the implementation method.

[0117] like Figure 7 As shown, the control device 6 in this embodiment includes a control unit 61 and a storage unit 62. The control unit 61 includes an information acquisition unit 61a and a lifting control unit 61b. Furthermore, the storage unit 62 stores scheme information 62a, liquid film change information 62b, wafer temperature information 62c, liquid volume information 62d, tilt information 62e, and film thickness distribution information 62f.

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

[0119] The computer's CPU, for example, reads and executes a program stored in ROM, while the information acquisition unit 61a and the lifting control unit 61b of the control unit 61 function. Furthermore, at least one or both of the information acquisition unit 61a and the lifting control unit 61b can be constructed from hardware such as ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0120] In addition, the storage unit 62 corresponds to, for example, RAM or HDD. RAM or HDD can store scheme information 62a, liquid film change information 62b, wafer temperature information 62c, liquid volume information 62d, tilt information 62e, and film thickness distribution information 62f.

[0121] Furthermore, the aforementioned program is stored in a computer-readable storage medium, and can also be installed from this storage medium into the storage unit 62 of the control device 6. Examples of computer-readable storage media include hard disks (HD), floppy disks (FD), optical disks (CD), magneto-optical disks (MO), and memory cards. In addition, the control device 6 can also access the aforementioned program and various information using other computers or portable storage media connected via wired or wireless networks.

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

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

[0124] The scheme information 62a includes information such as the volume and type of liquid in the liquid film L formed on the wafer W during the liquid film formation process. Furthermore, the scheme information 62a includes processing conditions such as the flow rate of the processing fluid during the drying process, the pressure within the processing container 31, and the temperature. The control unit 61 controls the liquid processing unit 17, the drying processing unit 18, etc., based on this scheme information 62a, thereby enabling the liquid processing unit 17, the drying processing unit 18, etc., to perform substrate processing such as liquid film formation and drying processes.

[0125] Furthermore, the scheme information 62a does not necessarily have to be obtained from the external device 47; for example, it can be generated in the control device 6.

[0126] Additionally, the information acquisition unit 61a can acquire liquid film change information 62b from the external device 47 and store it in the storage unit 62. The liquid film change information 62b represents the change of the liquid film L over time during the drying process. The liquid film change information 62b may include information representing the change of the liquid volume of the liquid film L over time during the drying process. Furthermore, the liquid film change information 62b may include information representing the change of the film thickness of the liquid film L over time during the drying process. If the liquid film L condenses during the drying process, there is a possibility that the thickness of the condensed liquid film L is greater than the initial film thickness. The liquid film change information 62b may include information on the change of the film thickness of the liquid film L over time due to condensation.

[0127] Additionally, the information acquisition unit 61a can acquire wafer temperature information 62c from the external device 47 and store it in the storage unit 62. The wafer temperature information 62c indicates the temperature of the wafer W during the drying process. Furthermore, the liquid film change information 62b and the wafer temperature information 62c can be obtained through prior experiments and simulations.

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

[0129] Additionally, the information acquisition unit 61a acquires information about the distance from the plurality of displacement sensors 43 to the lower surface of the wafer W, and calculates the tilt state of the wafer W based on the acquired information. Then, the information acquisition unit 61a stores the calculated tilt state of the wafer W as tilt information 62e in the storage unit 62.

[0130] Additionally, the information acquisition unit 61a acquires information about the thickness of the liquid film L from multiple film thickness sensors 45, and generates a film thickness distribution of the liquid film L on the wafer W based on the acquired information. Then, the information acquisition unit 61a stores the generated film thickness distribution of the liquid film L as film thickness distribution information 62f in the storage unit 62.

[0131] The lifting control unit 61b controls the multiple lifting mechanisms 32c of the holding unit 32 based on various information stored in the storage unit 62, thereby causing the multiple support components 32b to be raised or lowered as a whole or individually.

[0132] (5. Flow of supercritical fluids)

[0133] Next, refer to Figure 8 The flow of supercritical fluid within the treatment container 31 is described. Figure 8 This is a diagram illustrating an example of supercritical fluid flow within a processing space.

[0134] like Figure 8 As shown, the holding part 32 is disposed within the processing space 31a of the processing container 31 at a height position that does not contact the top surface 31b and bottom surface 31c of the processing space 31a. Furthermore, the wafer W, supported by a plurality of support members 32b, is disposed at a height position that does not contact the top surface 31b of the processing space 31a or the bottom surface 32a1 of the base part 32a.

[0135] A laminar flow of supercritical fluid is formed inside the processing container 31. This laminar flow of supercritical fluid is, for example, from the fluid supply head 37B (see reference). Figure 3 After being supplied into the processing space 31a, the supercritical fluid flows in the negative X-axis direction between the lower surface 32a2 of the base portion 32a and the bottom surface 31c of the processing space 31a. Then, the laminar flow of the supercritical fluid reaches the lower surface of the wafer W through the through-hole 32d, and flows in the negative X-axis direction between the lower surface of the wafer W and the bottom surface 32a1 of the base portion 32a, reaching the periphery of the wafer W. Afterwards, the laminar flow of the supercritical fluid enters the upper surface side of the wafer W, flowing in the positive X-axis direction 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 supercritical fluid flows laminarly between the lower surface of the wafer W and the bottom surface 32a1 of the holding portion 32, 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 32a1 of the base portion 32a, i.e., the protrusion of the support member 32b, is set to "HL". Furthermore, the initial value of the distance between the top surface 31b of the processing container 31 and the upper surface of the wafer W is set to "HU".

[0137] (6. Lifting control processing)

[0138] Next, refer to Figures 9-15 This section explains an example of the lifting control processing performed by the lifting control unit 61b. First, refer to... Figure 9 This illustrates an example of lifting control processing that uses scheme information 62a or liquid volume information 62d. Figure 9 This diagram illustrates an example of lifting control processing that uses scheme information 62a or liquid volume information 62d.

[0139] like Figure 9As shown, the lifting control unit 61b can obtain the liquid volume of the liquid film L before drying from the scheme information 62a or the liquid volume information 62d stored in the storage unit 62. The lifting control unit 61b controls multiple lifting mechanisms 32c to lift multiple support members 32b together, so that the height position of the wafer W in the processing space 31a is a height position corresponding to the liquid volume of the liquid film L before drying.

[0140] Here, "the height position corresponding to the liquid volume of the liquid film L before drying" means that the distance G between the upper surface of the liquid film L and the top surface 31b of the processing space 31a before the drying process begins is always a certain height position of the wafer W, which does not depend on the liquid volume of the liquid film L.

[0141] For example, when the liquid volume before drying is Xa, the lifting control unit 61b lowers the height of the multiple support members 32b compared to when the liquid volume before drying is Xb, which is less than Xa. This allows the size of the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L to be constant, regardless of the liquid volume of the liquid film L before drying. In other words, the flow rate and 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 constant, regardless of the liquid volume of the liquid film L before drying.

[0142] As described above, the lifting control unit 61b can also raise or lower the multiple support members 32b according to the liquid volume of the liquid film. Therefore, 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 can be set with high precision, so that the flow rate and velocity of the supercritical fluid flowing on the upper surface of the liquid film L are suitable for the drying process.

[0143] Furthermore, the control device 6 can also pre-store relevant information indicating the correlation between the liquid volume of the liquid film L and the height of the multiple support members 32b in the storage unit 62. In this case, the lifting control unit 61b can control the multiple lifting mechanisms 32c to raise or lower the multiple support members 32b according to the aforementioned relevant information stored in the storage unit 62.

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

[0145] Next, refer to Figure 10 and Figure 11 An example of lifting control processing using liquid film change information 62b will be explained. Figure 10 This diagram illustrates an example of how the support member 32b rises due to the varying liquid volume of the liquid film L during the drying process. Figure 11 The figure shows an example of how the support member 32b descends due to the varying liquid volume of the liquid film L during the drying process.

[0146] During the drying process, the volume of liquid in the liquid film L decreases over time. Therefore, the gap between the top surface 31b of the treatment space 31a and the upper surface of the liquid film L gradually increases as the volume of liquid in the liquid film L decreases. As a result, the flow rate and velocity of the supercritical fluid flowing along the upper surface of the liquid film L change over time.

[0147] Therefore, the lifting control unit 61b can also raise multiple support components 32b during the drying process based on the liquid film change information 62b and the changing liquid volume during the drying process. Specifically, as... Figure 10 As shown, the lifting control unit 61b raises multiple 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] Therefore, the size of the gap between the top surface 31b of the treatment space 31a and the upper surface of the liquid film L can be kept constant, regardless of the change in the liquid volume of the liquid film L during the drying process. In other words, the flow rate and velocity of the supercritical fluid flowing through the gap between the top surface 31b of the treatment space 31a and the upper surface of the liquid film L can be kept constant, regardless of the change in the liquid volume of the liquid film L during the drying process.

[0149] As described above, the lifting control unit 61b can also raise multiple support members 32b during the drying process based on the amount of liquid in the liquid film L. This allows, for example, the gap between the top surface 31b of the processing space 31a and the upper surface of the liquid film L to be maintained continuously during the drying process, such that the flow rate and velocity of the supercritical fluid flowing on the upper surface of the liquid film L are suitable for the drying process.

[0150] Alternatively, the lifting control unit 61b can raise multiple support components 32b during the drying process based on the liquid film change information 62b and the film thickness of the liquid film L that changes during the drying process.

[0151] In addition, such as 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 shown, multiple support members 32b are raised, thereby increasing the gap between the lower surface of the wafer W and the bottom surface 32a1 of the base portion 32a. This suppresses the radiant heat received by the wafer W from the base portion 32a. As a result, the temperature of the wafer W during the drying process can be reduced to X1°C, which is lower than X0°C and close to the desired temperature.

[0158] As described above, the lifting control unit 61b can also raise or lower the multiple support members 32b based on wafer temperature information indicating the temperature of the wafer W during the drying process. This allows the temperature of the wafer W during the drying process to approach the desired temperature, thus suppressing the collapse of the pattern formed on the upper surface of the wafer W.

[0159] Next, refer to Figure 14 and Figure 15 An example of lifting control processing using tilt information 62e will be explained. Figure 14 This is a diagram illustrating an example of a wafer W supported by multiple support members 32b tilting. Figure 15 This diagram illustrates an example of a case where the tilted wafer W is eliminated through lift control processing.

[0160] When the wafer W, supported by multiple support components 32b, warps or tilts, the in-plane uniformity of the liquid film L's thickness deteriorates, potentially reducing the performance of the drying process. For example, Figure 14 This indicates the case where the thickness of the liquid film L around the support member 32b4 becomes larger than that of other parts among the multiple support members 32b1~32b4.

[0161] In such a case, the lifting control unit 61b can also raise or lower multiple support components 32b1~32b4 individually based on tilt information 62e to eliminate warping or tilting of the wafer W. For example, in Figure 14 In the case shown, by raising the support member 32b4, the tilt of the wafer W can be eliminated. Thus, as... Figure 15 As shown, since the uniformity of the liquid film L can be improved, the collapse of the pattern formed on the upper surface of the wafer W can be suppressed.

[0162] (7. Variations)

[0163] In the above embodiment, it is described that a plurality of film thickness sensors 45 are arranged in the junction area 182 (refer to...). Figure 1 This is an example of a situation where multiple film thickness sensors 45 can also be configured in the processing area 181. Figure 16 This is a diagram showing the configuration of the film thickness sensor 45 in a modified example.

[0164] For example, such as Figure 16As shown, multiple film thickness sensors 45 can also be arranged above the processing container 31, and measure the film thickness of the liquid film L formed on the upper surface of the wafer W disposed in the processing space 31a via multiple transparent portions 31d provided in the processing container 31. With the configuration described above, multiple support members 32b can be raised or lowered during the drying process based on the film thickness of the liquid film L actually measured during the drying process.

[0165] In addition, Figure 16 Alternatively, multiple image sensors can be configured above the processing container 31 instead of multiple film thickness sensors 45. In this case, the information acquisition unit 61a can acquire information such as the liquid volume and film thickness of the liquid film L from images of the liquid film L during the drying process captured by the multiple image sensors.

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

[0167] As described above, the substrate processing apparatus of the embodiment (for example, the drying processing unit 18) is a substrate processing apparatus that performs a drying process. This drying process uses a supercritical processing fluid to dry a substrate (for example, a wafer W) on which a liquid film (for example, liquid film L) is formed on the patterning surface. The substrate processing apparatus includes a processing container (for example, a processing container 31), a holding part (for example, a holding part 32), and a supply part (for example, fluid supply heads 37A and 37B). The processing container can hold the substrate. The holding part can hold the substrate within the processing container. The supply part can supply processing fluid into the processing container. Furthermore, the holding part includes a base part (for example, a base part 32a), multiple support members (for example, multiple support members 32b), and a lifting mechanism (for example, multiple lifting mechanisms 32c). The base part is disposed below the substrate. The multiple support members are provided on the base part and can support the substrate from below. The lifting mechanism can raise and lower the multiple support members.

[0168] As described above, by configuring multiple support members capable of raising and lowering the substrate, processing conditions such as the flow rate and velocity of the supercritical fluid, which depend on the length of the support members, can be controlled with high precision and ease. Therefore, the collapse of the pattern formed on the upper surface of the substrate can be suppressed. Furthermore, compared to changing the length of the support members by replacing them with support members of different lengths, no replacement work is required.

[0169] Additionally, the substrate processing apparatus of the embodiment may also include a lifting control unit (as an example, lifting control unit 61b) that controls the lifting mechanism. In this case, the lifting control unit raises or lowers multiple support members according to the liquid volume or film thickness of the liquid film.

[0170] Additionally, the substrate processing apparatus of the embodiment may also include an acquisition unit (for example, information acquisition unit 61a) for acquiring the amount or thickness of the liquid film formed on the substrate before the substrate is placed into the processing container. In this case, a lifting control unit may be used to raise or lower multiple support members based on the amount or thickness of the liquid film obtained by the acquisition unit.

[0171] Thus, for example, it is possible to set the size of the gap between the top surface of the processing container and the upper surface of the liquid film with high precision, so that the flow rate and velocity of the supercritical fluid flowing on the upper surface of the liquid film are suitable for the drying process.

[0172] Furthermore, the substrate processing apparatus of the embodiment may also include an acquisition unit (for example, an information acquisition unit 61a) that acquires liquid film change information indicating the change in liquid volume or film thickness of the liquid film during the drying process over time. In this case, a lifting control unit may be used to raise or lower multiple support members based on the liquid film change information obtained by the acquisition unit, according to the change in liquid volume or film thickness during the drying process.

[0173] Thus, for example, it is possible to continuously maintain the size of the gap between the top surface of the processing vessel and the upper surface of the liquid film during the drying process, such that the flow rate and velocity of the supercritical fluid flowing on the upper surface of the liquid film are suitable for the drying process.

[0174] Additionally, the substrate processing apparatus of this embodiment may also include a lifting control unit (for example, lifting control unit 61b) and an acquisition unit (for example, information acquisition unit 61a). The lifting control unit can control the lifting mechanism. The acquisition unit can acquire the tilt status of the substrate supported by multiple support members. Furthermore, the lifting mechanism may be capable of individually lifting and lowering the multiple support members. In this case, the lifting control unit may also individually raise or lower the multiple support members based on the tilt status of the substrate obtained by the acquisition unit.

[0175] By individually raising or lowering multiple support components to eliminate substrate tilt, the uniformity of liquid film thickness can be improved, and the collapse of patterns formed on the upper surface of the substrate can be suppressed.

[0176] Alternatively, the lifting control unit can raise or lower multiple support components based on the liquid volume or thickness of the liquid film, so that the distance between the upper surface of the liquid film and the top surface (top surface 31b) inside the processing container (for example, processing space 31a). By making the gap between the upper surface of the supercritical fluid flow path, i.e., the liquid film, and the top surface inside the processing container, constant, the flow rate and velocity of the supercritical fluid can be made constant regardless of the liquid volume of the liquid film.

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

[0178] Furthermore, the embodiments disclosed in this invention are illustrative in all respects and should not be considered limiting. In fact, the above-described embodiments can be implemented in various ways. Moreover, the above-described embodiments can be omitted, substituted, or modified in various ways as long as they do not depart from the scope and spirit of the appended claims.

Claims

1. A substrate processing apparatus, characterized in that: The substrate processing apparatus is capable of performing a drying process using a supercritical processing fluid to dry a substrate on which a liquid film has been formed on the patterning surface, including: A processing container for housing the substrate; and A film thickness sensor that measures the thickness of the liquid film housed in the substrate of the processing container. The processing container includes a transparent portion through which the substrate housed inside the processing container can be seen. The film thickness sensor measures the film thickness via the transparent portion.

2. The substrate processing apparatus according to claim 1, characterized in that: The transparent portion is located at the top of the processing container. The film thickness sensor is positioned above the processing container.

3. The substrate processing apparatus according to claim 1, characterized in that: The film thickness sensor measures the film thickness during the drying process.

4. The substrate processing apparatus according to claim 3, characterized in that, Also includes: The substrate is held within the processing container. The holding portion includes a plurality of support members that support the substrate from below and a lifting mechanism for the plurality of support members. A lifting control unit that controls the lifting mechanism; and The acquisition unit obtains information about the film thickness from the film thickness sensor. The lifting control unit raises or lowers the plurality of support components based on the film thickness obtained by the acquisition unit.

5. The substrate processing apparatus according to claim 4, characterized in that: The lifting control unit raises or lowers the plurality of support components according to the film thickness that changes during the drying process.

6. The substrate processing apparatus according to any one of claims 1 to 5, characterized in that: Includes multiple film thickness sensors, At least one of the plurality of film thickness sensors measures the film thickness at the outer periphery of the substrate.

7. The substrate processing apparatus according to claim 6, characterized in that: At least one of the plurality of film thickness sensors measures the film thickness at the central portion of the substrate.

8. The substrate processing apparatus according to claim 6, characterized in that: The processing container includes a plurality of the transparent portions. Each of the plurality of film thickness sensors measures the film thickness via a corresponding transparent portion among the plurality of transparent portions.

9. A method for drying a substrate, characterized in that: The substrate drying method uses a supercritical processing fluid to dry a substrate on which a liquid film has been formed on the patterning surface, including: In the step of storing the substrate in a processing container with a transparent portion, the substrate stored inside the processing container is visible through the transparent portion; and The step of using a film thickness sensor to measure the thickness of the liquid film on the substrate housed in the processing container via the transparent portion.

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