CN108735630B - Substrate processing apparatus and substrate processing method - Google Patents

Abstract

The invention provides a substrate processing apparatus capable of adjusting the gap between a discharge nozzle and a substrate with high accuracy. The liquid treatment unit (U1) comprises: a holding unit (23) for holding a wafer (W); a nozzle (40) for discharging the coating liquid from the front end (41) to the wafer (W) held by the holding part (23); a drive unit (30) for moving the nozzle (40) to above the wafer (W); and a nozzle sensor (60) that detects the state of the tip (41) of the nozzle (40) that is moved by the drive unit (30).

Description

Substrate processing apparatus and substrate processing method

Technical Field

The present invention relates to a substrate processing apparatus and a substrate processing method.

Background

Patent document 1 discloses a substrate processing apparatus for applying a coating liquid in a spiral shape (spiral coating) on a surface of a substrate. In spiral coating, a discharge nozzle is moved in a predetermined direction along the surface of a substrate between a rotation shaft and the peripheral edge of the substrate during rotation of the substrate, and a coating liquid is discharged from the discharge nozzle.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication 2016-010796

Disclosure of Invention

Technical problem to be solved by the invention

Here, in the spiral coating, the thickness of the gap formed between the discharge nozzle and the substrate is substantially uniform. In this way, in spiral coating, the gap between the discharge nozzle and the substrate directly affects the film thickness, and therefore, the gap needs to be adjusted with high accuracy.

The present invention has been made in view of the above-described problems, and an object thereof is to adjust a gap between a discharge nozzle and a substrate with high accuracy.

Means for solving the problems

A substrate processing apparatus according to an embodiment of the present invention includes: a holding section for holding the substrate; at least one liquid contact type discharge nozzle for discharging the coating liquid from the front end portion of the substrate held by the holding portion; a driving part for moving the discharge nozzle above the substrate; and a first sensor for detecting the state of the front end of the discharge nozzle moved by the driving part.

In the substrate processing apparatus according to one embodiment of the present invention, the state of the tip portion of the discharge nozzle moved by the driving unit is detected by the first sensor. Thus, for example, information such as the distance between the nozzle and the nozzle, the levelness of the tip portion of the nozzle, or the state of the coating liquid fixed to the tip portion can be obtained, and the gap between the nozzle and the substrate at the time of discharging the coating liquid can be appropriately set by using such information. As described above, according to the substrate processing apparatus of one embodiment of the present invention, the gap between the discharge nozzle and the substrate can be adjusted with high accuracy.

The first sensor may be disposed below a movement path of the discharge nozzle moved by the driving part. The coating liquid is discharged from above the substrate (i.e., from the lower part of the discharge nozzle, i.e., the tip end) by the discharge nozzle moved by the driving unit, and the state of the tip end of the discharge nozzle can be detected well by the first sensor disposed below the movement path of the discharge nozzle. That is, the gap between the discharge nozzle and the substrate can be adjusted with higher accuracy.

The driving unit may move the discharge nozzle so that the state of the plurality of portions of the front end portion can be detected by the first sensor. It is difficult to completely flatten the tip end portion of the discharge nozzle, and irregularities of the order of several tens of μm may be generated between regions of the tip end portion. By detecting the states of the plurality of portions of the tip portion by the first sensor by the scanning operation, the gap between the discharge nozzle and the substrate can be set in consideration of the irregularities.

The substrate processing apparatus may further include a plurality of discharge nozzles, and the driving unit may select at least 1 discharge nozzle from the plurality of discharge nozzles, and move the selected discharge nozzle upward of the substrate through a detection range of the first sensor. Thus, for example, the discharge nozzle can be prepared for each application liquid, and the gap between the discharge nozzle and the substrate can be set for each discharge nozzle.

The substrate processing apparatus may further include a second sensor for detecting a distance from the substrate, and the driving unit may include an arm for holding the discharge nozzle and the second sensor, and the arm may move the discharge nozzle and the second sensor. Thereby, the distance from the substrate can be detected by the second sensor held by the arm together with the discharge nozzle. That is, the distance between the discharge nozzle and the substrate can be appropriately determined, and the gap between the discharge nozzle and the substrate can be adjusted with higher accuracy.

The substrate processing apparatus may further include a control unit that moves the second sensor upward of the substrate through a detection range of the first sensor, and the control unit may perform: obtaining a sensor separation distance, which is a separation distance between the first sensor and the second sensor, from at least either one of the first sensor and the second sensor; obtaining a nozzle interval distance, which is an interval distance between the first sensor and the discharge nozzle, from the first sensor; and deriving a difference in mounting position of the second sensor and the discharge nozzle based on the sensor spacing distance and the nozzle spacing distance. By deriving the mounting difference, which is the difference between the mounting positions of the second sensor and the discharge nozzle, the distance between the discharge nozzle and the substrate can be determined with high accuracy based on the detection result of the second sensor. This enables the gap between the discharge nozzle and the substrate to be adjusted with higher accuracy.

The control section may further perform the following processing: obtaining a separation distance from the substrate from the second sensor; the driving part is controlled so that the distance between the substrate and the discharge nozzle is a predetermined height of the discharge nozzle, and the distance between the substrate and the discharge nozzle is derived based on the difference between the distance from the substrate and the mounting position obtained from the second sensor. Accordingly, the gap between the discharge nozzle and the substrate can be appropriately adjusted in consideration of the mounting difference, and the discharge nozzle can be set to a predetermined discharge nozzle height.

The substrate processing apparatus further includes a cleaning section for cleaning the discharge nozzle with a cleaning liquid, and the control section may further perform the following processing: the cleaning unit is controlled to clean the discharge nozzle based on the state of the tip portion detected by the first sensor. Thus, for example, when the gap between the discharge nozzle and the substrate is affected by the coating liquid fixed to the tip portion, the cleaning portion can be cleaned. This makes it possible to adjust the gap between the discharge nozzle and the substrate with higher accuracy, and to appropriately suppress the change in the formed film thickness or the like caused by contamination of the tip portion.

The cleaning part may further include: a cleaning liquid supply unit for supplying a cleaning liquid; and a cleaning liquid removing part for removing the cleaning liquid attached to the front end of the discharge nozzle after the cleaning liquid is supplied. In the case where the cleaning liquid and the coating liquid are mixed, the tip end portion of the nozzle is contaminated when the mixed liquid is solidified, and the film thickness may be affected. Thus, by removing the cleaning liquid from the front end portion after cleaning, mixing of the cleaning liquid and the coating liquid can be suppressed, and the front end portion can be kept clean, and the change in the formed film thickness can be appropriately suppressed.

The substrate processing method according to one embodiment of the present invention includes: a step of moving a liquid contact type discharge nozzle for discharging a coating liquid from a front end portion to a substrate upward of the substrate; detecting, by a first sensor, a state of a front end portion of a discharge nozzle moving toward a substrate; and setting a discharge height of the discharge nozzle with respect to the substrate, that is, a discharge nozzle height, based on the detection result.

The above substrate processing method may further include: a step of acquiring a sensor distance from at least either one of the first sensor and the second sensor, the sensor distance being a distance between the second sensor and the first sensor for detecting a distance from the substrate; a step of acquiring a nozzle interval distance, which is a distance between the first sensor and the discharge nozzle, from the first sensor; and deriving a difference between the mounting positions of the second sensor and the discharge nozzle based on the sensor spacing distance and the nozzle spacing distance.

The above substrate processing method may further include: a step of acquiring a separation distance from the substrate from the second sensor; and a step of deriving the height of the discharge nozzle based on the difference between the distance from the substrate and the mounting position obtained from the second sensor.

The above substrate processing method may further include: and a step of controlling the cleaning part to clean the discharge nozzle according to the state of the front end part detected by the first sensor.

A storage medium according to an embodiment of the present invention is a computer-readable storage medium storing a program for causing an apparatus to execute the substrate processing method described above.

Effects of the invention

According to the present invention, the gap between the discharge nozzle and the substrate can be adjusted with high accuracy.

Drawings

Fig. 1 is a perspective view showing a schematic configuration of a substrate processing system according to a first embodiment.

Fig. 2 is a sectional view taken along line II-II in fig. 1.

Fig. 3 is a sectional view taken along line III-III in fig. 2.

Fig. 4 is a schematic view of a liquid treatment unit of the first embodiment.

Fig. 5 is a hardware configuration diagram of the controller.

Fig. 6 is a diagram illustrating derivation of the mounting difference between the wafer sensor and the nozzle.

Fig. 7 is a diagram illustrating derivation of the mounting difference between the wafer sensor and the nozzle.

Fig. 8 is a diagram illustrating derivation of the mounting difference between the wafer sensor and the nozzle.

Fig. 9 is a diagram illustrating derivation of the mounting difference between the wafer sensor and the nozzle.

Fig. 10 is a diagram illustrating height adjustment of the nozzle.

Fig. 11 is a diagram illustrating height adjustment of the nozzle.

Fig. 12 is a diagram illustrating height adjustment of the nozzle.

Fig. 13 is a flow chart of a liquid treatment sequence.

Fig. 14 is a diagram illustrating a series of processes of the advance operation and the spiral coating operation.

Fig. 15 is a flowchart of the installation difference derivation processing procedure.

Fig. 16 is a flowchart of the nozzle height adjustment processing sequence.

Fig. 17 is a diagram illustrating a problem to be solved by the substrate processing system according to the second embodiment.

Fig. 18 is a diagram illustrating a problem to be solved by the substrate processing system according to the second embodiment.

Fig. 19 is a diagram illustrating a problem to be solved by the substrate processing system according to the second embodiment.

Fig. 20 is a diagram illustrating a problem to be solved by the substrate processing system according to the second embodiment.

Fig. 21 is a diagram illustrating a problem to be solved by the substrate processing system according to the second embodiment.

Fig. 22 is a diagram illustrating a problem to be solved by the substrate processing system according to the second embodiment.

Fig. 23 is a diagram showing drying of the nozzle by air blowing.

Fig. 24 is a schematic view of the cleaning section.

Fig. 25 is a schematic view of a blower.

Fig. 26 is a flowchart of the cleaning process sequence.

Fig. 27 is a schematic view of a cleaning section according to a modification.

Fig. 28 is a schematic view of a cleaning section according to a modification.

Description of the reference numerals

2 … … coating and developing apparatus (substrate processing apparatus)

23 … … holder

30 … … drive part

40 … … nozzle (discharge nozzle)

41 … … front end

50 … … wafer sensor (second sensor)

60 … … nozzle sensor (first sensor)

70. 70A, 70B, 70C … … cleaning part

72A … … cleaning liquid supply part

73A … … air blower (cleaning liquid removing part)

73B … … absorber (cleaning solution remover)

73C … … Water supply portion (cleaning liquid removal portion)

100. 100A … … controller (control)

190 … … cleaning liquid

W … … wafer.

Detailed Description

First embodiment

Hereinafter, the first embodiment will be described in detail with reference to the drawings. In the description, the same elements or elements having the same functions are denoted by the same reference numerals, and repetitive description thereof will be omitted.

(substrate processing System)

The substrate processing system 1 is a system that performs formation of a photosensitive film on a substrate, exposure of the photosensitive film, and development of the photosensitive film. The substrate to be processed is, for example, a semiconductor wafer W. The photosensitive coating film is, for example, a resist film.

The substrate processing system 1 has a coating and developing apparatus 2 and an exposure apparatus 3. The exposure device 3 performs exposure processing of a resist film formed on the wafer W. Specifically, the exposure target portion of the resist film is irradiated with an energy beam by a method such as liquid immersion exposure. Before the exposure process by the exposure device 3, the coating and developing device 2 performs a process of forming a resist film on the surface of the wafer W, and after the exposure process, performs a development process of the resist film.

(coating and developing apparatus)

The configuration of the coating and developing apparatus 2 will be described below as an example of a substrate processing apparatus. As shown in fig. 1 to 3, the coating and developing apparatus 2 includes a carrier block 4, a process block 5, an interface block 6, and a controller 100.

The carrier block 4 carries out the introduction into and the removal from the wafer W in the coating and developing apparatus 2. For example, the carrier block 4 can support a plurality of carriers 11 for wafers W, and incorporates the transfer arm A1. The carrier 11 accommodates a plurality of wafers W in a circular shape, for example. The transfer arm A1 takes out the wafer W from the carrier 11, transfers the wafer W to the processing block 5, and receives the wafer W from the processing block 5 to return the wafer W to the carrier 11.

The processing block 5 has a plurality of processing modules 14, 15, 16, 17. As shown in fig. 2 and 3, the process modules 14, 15, 16, 17 have a plurality of liquid processing units U1, a plurality of heat processing units U2, and a transfer arm A3 for transferring the wafer W to these units built therein. The process module 17 further incorporates a direct transfer arm A6 for transferring the wafer W without passing through the liquid processing unit U1 and the heat processing unit U2. The liquid treatment unit U1 applies a treatment liquid to the surface of the wafer W. The heat treatment unit U2 includes, for example, a hot plate and a cooling plate, heats the wafer W by the hot plate, and cools the heated wafer W by the cooling plate, thereby performing heat treatment.

The process module 14 forms a lower layer film on the surface of the wafer W using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 of the processing module 14 applies a processing liquid for forming a lower layer film on the wafer W. The heat treatment unit U2 of the treatment module 14 performs various heat treatments accompanied with formation of the underlying film.

The processing module 15 forms a resist film on the underlying film using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 of the processing module 15 applies a processing liquid (coating liquid) for forming a resist film onto the underlying film. The heat treatment unit U2 of the treatment module 15 performs various heat treatments accompanied with formation of a resist film. Details of the liquid processing unit U1 of the processing module 15 will be described later.

The processing module 16 forms an upper layer film on the resist film using the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 of the processing module 16 applies a processing liquid for forming an upper layer film onto the resist film. The heat treatment unit U2 of the treatment module 16 performs various heat treatments accompanied with formation of an upper layer film.

The processing module 17 performs development processing of the resist film after exposure by the liquid processing unit U1 and the heat processing unit U2. The liquid processing unit U1 of the processing module 17 applies a processing liquid (developing liquid) for development to the surface of the exposed wafer W, and then washes the surface with a processing liquid (rinsing liquid) for cleaning, thereby performing a development process of the resist film. The heat treatment unit U2 of the process module 17 performs various heat treatments accompanied with the development treatment. Specific examples of the heat treatment include a heat treatment before development (PEB: post Exposure Bake) and a heat treatment after development (PB: post Bake).

A shelving unit U10 is provided on the carrier block 4 side in the processing block 5. The shelving unit U10 is divided into a plurality of cells arranged in the up-down direction. A lift arm A7 is provided near the shelving unit U10. The lift arm A7 lifts and lowers the wafer W between the cells of the shelf unit U10. A shelving unit U11 is provided on the interface block 6 side in the processing block 5. The shelving unit U11 is divided into a plurality of cells arranged in the up-down direction.

The interface block 6 transfers the wafer W to and from the exposure apparatus 3. For example, the interface block 6 has a transfer arm A8 built therein and is connected to the exposure apparatus 3. The transfer arm A8 transfers the wafer W placed in the shelf unit U11 to the exposure apparatus 3, receives the wafer W from the exposure apparatus 3, and returns the wafer W to the shelf unit U11.

The controller 100 controls the coating and developing apparatus 2 to perform, for example, coating and developing processes in the following order.

First, the controller 100 controls the transfer arm A1 to transfer the wafers W in the carrier 11 to the shelf unit U10, and controls the lift arm A7 to dispose the wafers W in the chambers for the process modules 14.

Next, the controller 100 controls the transfer arm A3 to transfer the wafer W of the shelf unit U10 to the liquid processing unit U1 and the heat processing unit U2 in the process module 14, and controls the liquid processing unit U1 and the heat processing unit U2 to form a lower film on the surface of the wafer W. Thereafter, the controller 100 controls the transfer arm A3 to return the wafer W on which the lower film is formed to the shelf unit U10, and controls the lift arm A7 to dispose the wafer W in the chamber for the process module 15.

Next, the controller 100 controls the transfer arm A3 to transfer the wafer W of the shelf unit U10 to the liquid processing unit U1 and the heat processing unit U2 in the process module 15, and controls the liquid processing unit U1 and the heat processing unit U2 to form a resist film on the lower film of the wafer W. Thereafter, the controller 100 controls the transfer arm A3 to return the wafer W to the shelf unit U10, and controls the lift arm A7 to dispose the wafer W in the chamber for the process module 16.

Next, the controller 100 controls the transfer arm A3 to transfer the wafer W of the shelf unit U10 to each unit in the process module 16, and controls the liquid processing unit U1 and the heat processing unit U2 to form an upper layer film on the resist film of the wafer W. Thereafter, the controller 100 controls the transfer arm A3 to return the wafer W to the shelf unit U10, and controls the lift arm A7 to dispose the wafer W in the chamber for the process module 17.

Next, the controller 100 controls the direct transfer arm A6 to transfer the wafer W of the shelf unit U10 to the shelf unit U11, and controls the transfer arm A8 to send the wafer W to the exposure apparatus 3. Thereafter, the controller 100 controls the transfer arm A8 to receive the wafer W subjected to the exposure process from the exposure apparatus 3 and return the wafer W to the shelf unit U11.

Next, the controller 100 controls the transfer arm A3 to transfer the wafer W of the shelf unit U11 to each unit in the process module 17, and controls the liquid processing unit U1 and the heat processing unit U2 to perform development processing on the resist film of the wafer W. Thereafter, the controller 100 controls the transfer arm A3 to return the wafer W to the shelf unit U10, and controls the lift arm A7 and the transfer arm A1 to return the wafer W to the carrier 11. The coating and developing process is completed through the above process.

The specific configuration of the substrate processing apparatus is not limited to the configuration of the coating and developing apparatus 2 illustrated above. The substrate processing apparatus may be any apparatus as long as it has a liquid processing unit U1 for forming a coating film (the liquid processing unit U1 of the processing modules 14, 15, 16) and a controller 100 capable of controlling the same.

(liquid treatment Unit)

Next, the liquid processing unit U1 of the processing module 15 will be described in detail. As shown in fig. 4, the liquid processing unit U1 of the processing module 15 includes a rotation holding portion 20, a driving portion 30, a nozzle 40 (discharge nozzle), a wafer sensor 50 (second sensor), a nozzle sensor 60 (first sensor), a cleaning portion 70, and a controller 100 (control portion).

The rotation holding portion 20 has a rotation portion 21 and a holding portion 23. The rotating portion 21 has a main shaft 22 protruding upward. The rotation unit 21 rotates the spindle 22 using, for example, a motor or the like as a power source. The holding portion 23 is provided at the front end portion of the spindle 22. The wafer W is horizontally arranged on the holding portion 23. The holding portion 23 holds the wafer W substantially horizontally by suction, for example. That is, the rotation holding portion 20 rotates the wafer W around an axis (rotation axis) perpendicular to the surface of the wafer W in a state where the posture of the wafer W is substantially horizontal. The rotation holding unit 20 rotates the wafer W clockwise when viewed from above, for example.

The driving unit 30 is configured to drive the nozzle 40. The driving unit 30 moves the nozzle 40 and the wafer sensor 50 over the wafer W through the detection range of the nozzle sensor 60 (see fig. 12). The driving section 30 has an arm 31 configured to be able to hold the nozzle 40 and the wafer sensor 50. The arm portion 31 has a holding member 32 extending in the horizontal direction. The holding member 32 is configured to be able to hold the nozzle 40 (see fig. 7) at one end side in the horizontal direction and hold the wafer sensor 50 at the other end side. The arm 31 is movable in the horizontal direction and the up-down direction using, for example, a motor or the like as a power source. Along with the movement of the arm 31, the nozzle 40 and the wafer sensor 50 held by the arm 31 move in the horizontal direction and the up-down direction. That is, the driving unit 30 is configured to be capable of moving the nozzle 40 together with the wafer sensor 50 by the arm 31.

The driving unit 30 moves the nozzle 40 so that the nozzle sensor 60 detects the state of the plurality of portions of the distal end portion 41 of the nozzle 40 by scanning the nozzle 40 with respect to the nozzle sensor 60 (details will be described later). The driving unit 30 selects 1 nozzle 40 from the plurality of nozzles 40 prepared from the coating liquid, and moves the selected nozzle 40 upward of the wafer W through a detection range of the nozzle sensor 60 (described in detail later). When the coating liquid is discharged from the nozzle 40 toward the wafer W, the driving unit 30 moves in the radial direction of the wafer W along a line perpendicular to the rotation axis of the wafer W.

The nozzle 40 discharges the coating liquid from the front end 41 of the wafer W held by the holding portion 23. The nozzle 40 is a liquid contact type discharge nozzle, and a liquid contact surface facing the surface of the wafer W and a discharge port opening in the liquid contact surface to discharge the coating liquid are formed at the tip portion 41. The nozzle 40, which is a liquid contact type nozzle, discharges the coating liquid to the wafer W so that the liquid contact surface contacts the liquid reservoir of the coating liquid. In the liquid processing unit U1, the nozzles 40 are prepared for each type of coating liquid. That is, the liquid processing unit U1 has a plurality of nozzles 40. The nozzle 40 is disposed above the wafer W held by the holding portion 23 by the driving portion 30. The nozzle 40 discharges the coating liquid from a discharge port facing vertically downward at its front end 41. By drying the coating liquid, a coating film R is formed on the surface of the wafer W (see fig. 4). Examples of the coating liquid include a resist liquid for forming a resist pattern, a polyimide liquid for forming a polyimide film for holding a circuit, a liquid for forming an antireflection film (for example, an underlying antireflection coating film), a liquid for forming a SOG (Spin on Glass) film, a liquid for forming an underlying film, and the like. The nozzle 40 is connected to a liquid reservoir (not shown) for storing the coating liquid, for example, via a pipe (not shown), and discharges the coating liquid supplied from the liquid reservoir downward to supply the coating liquid to the wafer W.

The wafer sensor 50 is a displacement sensor that detects a distance (see fig. 10) from the wafer W. As the wafer sensor 50, for example, a sensor that obtains wavelength information of reflected light from an object (object) of a detection distance as color information and derives a distance from the object is used. By deriving the separation distance based on such color information, for example, an installation error (such as the inability to accurately derive the separation distance when reflected light is incident from an oblique direction) which is a problem when a laser displacement meter is used does not become a problem. The wafer sensor 50 is held by the arm 31 (specifically, the end of the holding member 32) of the driving unit 30 as described above, and is movable in the horizontal direction and the up-down direction together with the arm 31. The wafer sensor 50 is disposed at a position where the distance from the nozzle sensor 60 can be detected. That is, the wafer sensor 50 is configured to be able to detect a separation distance from the nozzle sensor 60 at least in a part of a movement path that is moved by the arm 31. The wafer sensor 50 outputs the measured distance information to the controller 100 at, for example, a predetermined time interval.

The nozzle sensor 60 detects the state of the tip portion 41 of the nozzle 40 moved by the driving portion 30. The state of the front end 41 refers to, for example, the levelness of each region of the front end 41 or the state of the coating liquid fixed to the front end 41. The nozzle sensor 60 is a displacement sensor that detects the state of the tip 41 by detecting, for example, the distance from the tip 41 of the nozzle 40. As the nozzle sensor 60, for example, a sensor that obtains wavelength information of reflected light from an object of a detection distance as color information to derive a distance from the object is used. The nozzle sensor 60 is disposed below the movement path of the nozzle 40 and the wafer sensor 50 moved by the driving section 30. The nozzle sensor 60 is configured to be able to detect a distance from the tip 41 of the nozzle 40 and a distance from the wafer sensor 50. The nozzle sensor 60 detects the state of a plurality of portions (i.e., detects the distance between the plurality of portions) of the nozzle 40 that performs a scanning operation with respect to the nozzle sensor 60. The nozzle sensor 60 outputs the measured distance information to the controller 100 at, for example, a predetermined time interval.

The cleaning section 70 is configured to clean the nozzle 40 with a cleaning liquid. The cleaning section 70 includes a cleaning chamber 71 that houses the nozzle 40. For example, in a state where the nozzle 40 from which the coating liquid is discharged is stored in the cleaning chamber 71, the cleaning section 70 supplies the cleaning liquid from the cleaning liquid supply section (not shown) into the cleaning chamber 71, and the tip 41 of the nozzle 40 is cleaned by forming a vortex of the cleaning liquid. As the cleaning liquid, for example, a diluent is used.

The controller 100 is made up of one or more control computers. For example, the controller 100 has the circuit 120 shown in fig. 5. The circuit 120 has one or more processors 121, memory 122, storage 123, input output 124, and timer 125.

The input/output port 124 inputs/outputs electrical signals to/from the rotating section 21, the driving section 30, the wafer sensor 50, the nozzle sensor 60, and the cleaning section 70. The timer 125 counts the reference pulse of a predetermined period to measure the elapsed time. The storage device 123 has a recording medium such as a hard disk that can be read by a computer. The recording medium records a program for executing a substrate processing sequence described later. The recording medium may be a removable medium such as a nonvolatile semiconductor memory, a magnetic disk, or an optical disk. The memory 122 temporarily records the program downloaded from the recording medium of the storage device 123 and the operation result of the processor 121. The processor 121 cooperates with the memory 122 to execute the programs and thereby constitute the respective functional modules described above.

The hardware configuration of the controller 100 is not limited to the configuration of each functional module by a program. For example, each functional block of the controller 100 may be constituted by a dedicated logic circuit or an ASIC (Application Specific Integrated Circuit ) formed by integrating the dedicated logic circuit.

The controller 100 performs predetermined control to derive a mounting difference (difference in mounting position in the up-down direction) between the wafer sensor 50 and the nozzle 40. That is, the controller 100 is configured to execute the following processing: obtaining a sensor separation distance, which is a separation distance between the nozzle sensor 60 and the wafer sensor 50, from at least either one of the nozzle sensor 60 and the wafer sensor 50; a nozzle interval distance, which is a distance between the nozzle sensor 60 and the nozzle 40, is obtained from the nozzle sensor 60; the difference in the mounting of the wafer sensor 50 to the nozzle 40 is derived based on the sensor spacing distance and the nozzle spacing distance.

The controller 100 performs predetermined control such that the height of the nozzle 40 for discharging the coating liquid is set (adjusted) in consideration of the mounting difference. That is, the controller 100 is configured to further execute the following processing: obtaining a separation distance from the wafer W from the wafer sensor 50; the driving unit 30 is controlled so that the distance between the wafer W and the nozzle 40 derived based on the distance from the wafer W obtained from the wafer sensor 50 and the mounting difference is a predetermined discharge nozzle height.

Further, the controller 100 is configured to control the cleaning section 70 so as to clean the nozzle 40 based on the state of the coating liquid of the tip 41 detected by the nozzle sensor 60.

As shown in fig. 4, the controller 100 includes, as functional blocks, an installation difference deriving unit 101, a nozzle setting unit 102, a coating control unit 103, and a cleaning control unit 104.

The mounting difference deriving unit 101 derives a mounting difference between the wafer sensor 50 and the nozzle 40. Specifically, the mounting difference deriving unit 101 determines a first movement amount a (see fig. 6) which is a movement amount of the driving unit 30 when the wafer sensor 50 is positioned directly above the nozzle sensor 60 and a predetermined distance (for example, 40mm. Hereinafter, a case where the predetermined distance is 40 mm) and a second movement amount B (see fig. 7) which is a movement amount of the driving unit 30 when the nozzle 40 is positioned directly above the nozzle sensor 60 by 40mm, and determines a mounting difference C (see fig. 9) between the wafer sensor 50 and the nozzle 40 by subtracting the second movement amount B from the first movement amount a. Each of the first movement amount a and the second movement amount B is a movement amount of the arm portion 31 downward from a Z-axis HOME (HOME) position which is a mark position of the arm portion 31 in the up-down direction (refer to fig. 6 and 7). The derivation of the mounting difference by the mounting difference derivation unit 101 will be described in detail with reference to fig. 6 to 9.

As shown in fig. 6, the mounting difference deriving unit 101 first controls the driving unit 30 so that the wafer sensor 50 moves to a position 40mm (design value) right above the nozzle sensor 60. The driving unit 30 moves the arm 31 downward by a predetermined amount (design value) from the Z-axis home position under the control of the mounting difference deriving unit 101. In this state, the mounting difference deriving unit 101 controls the driving unit 30 so that the distance from the nozzle sensor 60 at least at both end portions of the wafer sensor 50 is measured by the nozzle sensor 60. The driving unit 30 moves the wafer sensor 50 in the left-right direction while maintaining the height in the up-down direction under the control of the mounting-difference deriving unit 101. The mounting difference deriving unit 101 obtains the distance from the nozzle sensor 60 between the two end portions of the wafer sensor 50 from the nozzle sensor 60. The mounting difference deriving unit 101 determines the shorter one of the obtained separation distances of the both end portions as the sensor separation distance. The sensor interval distance is a measurement value actually measured by the nozzle sensor 60.

The installation difference deriving unit 101 derives a value corresponding to the sensor separation distance. The value corresponding to the sensor separation distance is a value derived from the difference between the sensor separation distance and the design value. For example, when the sensor separation distance is 39mm smaller than the design value, that is, 40mm, the value corresponding to the sensor separation distance is +1mm obtained by subtracting 39mm from 40 mm. When the sensor separation distance is 41mm larger than the design value, that is, 40mm, the value corresponding to the sensor separation distance is-1 mm obtained by subtracting 41mm from 40 mm. The mounting difference deriving unit 101 subtracts the value corresponding to the sensor pitch distance from the downward movement amount from the Z-axis home position at the time of the design value, and thereby determines a first movement amount a (see fig. 6) which is the movement amount of the driving unit 30 when the wafer sensor 50 is positioned 40mm directly above the nozzle sensor 60 (the downward movement amount from the Z-axis home position). The first movement amount a is a value corresponding to the sensor interval distance which is a measurement value actually measured by the nozzle sensor 60.

Next, as shown in fig. 7, the mounting difference deriving unit 101 controls the driving unit 30 so that the nozzle 40 moves to a position 40mm (design value) right above the nozzle sensor 60. The driving unit 30 moves the arm 31 downward by a predetermined amount (design value) from the Z-axis home position under the control of the mounting difference deriving unit 101. In this state, the mounting difference deriving unit 101 controls the driving unit 30 so that the nozzle 40 performs a scanning operation with respect to the nozzle sensor 60. The driving unit 30 scans the nozzle 40 in the left-right direction with respect to the nozzle sensor 60 while maintaining the height in the up-down direction under the control of the mounting difference deriving unit 101. In this state, the mounting difference deriving unit 101 obtains the distance between the wafer sensor 50 and the nozzle sensor 60 from the nozzle sensor 60 at predetermined time intervals (for example, every 100 ms), for example. As shown in fig. 8, for example, the obtained plurality of separation distances can be set to values of the order of 22 μm to 41 μm in each region (horizontal position) of the tip portion 41 of the nozzle 40. The installation difference deriving unit 101 determines the shortest distance among the acquired plurality of separation distances as the nozzle separation distance. The nozzle interval distance is a measurement value actually measured by the nozzle sensor 60.

The installation difference deriving unit 101 derives a value corresponding to the nozzle interval distance. The value corresponding to the nozzle interval distance is a value derived from the difference between the sensor interval distance and the design value. For example, when the nozzle spacing distance is 39mm smaller than the design value, that is, 40mm, the +1mm obtained by subtracting 39mm from 40mm becomes a value corresponding to the nozzle spacing distance. When the nozzle spacing distance is 41mm larger than the design value, that is, 40mm, the value corresponding to the nozzle spacing distance is-1 mm obtained by subtracting 41mm from 40 mm. The mounting difference deriving unit 101 subtracts the above-described value corresponding to the nozzle spacing distance from the movement amount of the Z-axis home position downward when the design value is set, and thereby determines a second movement amount B (see fig. 7) which is the movement amount of the driving unit 30 when the nozzle 40 is positioned 40mm directly above the nozzle sensor 60 (movement amount of the Z-axis home position downward). The second movement amount B is a value corresponding to the nozzle interval distance, which is a measurement value actually measured by the nozzle sensor 60.

The mounting difference deriving unit 101 subtracts the second movement amount B from the first movement amount a to determine a mounting difference C (see fig. 9) between the wafer sensor 50 and the nozzle 40. The mounting difference C is used for processing by the nozzle setting unit 102 described later.

The nozzle setting unit 102 controls the nozzle 40 to have a predetermined nozzle height based on the mounting difference. As shown in fig. 10, the nozzle setting unit 102 controls the driving unit 30 so that the wafer sensor 50 moves 40mm (design value) directly above the center of the wafer W (wafer center). The driving unit 30 moves the arm 31 downward by a predetermined amount (design value) from the Z-axis home position according to the control of the nozzle setting unit 102. In this state, the nozzle setting unit 102 controls the driving unit 30 so that the wafer sensor 50 performs a scanning operation with respect to the wafer W. The driving unit 30 scans the wafer sensor 50 in the left-right direction with respect to the wafer W while maintaining the height in the up-down direction under the control of the nozzle setting unit 102. The nozzle setting unit 102 obtains a distance from the wafer W at predetermined time intervals (for example, every 100 ms) from the wafer sensor 50. As shown in fig. 11, for example, the obtained plurality of pitch distances are obtained in various values corresponding to the projections and depressions of the pattern of the wafer W. The nozzle setting unit 102 determines the shortest distance among the acquired plurality of separation distances as the wafer separation distance. The wafer spacing distance is a measurement value actually measured by the wafer sensor 50.

The nozzle setting unit 102 derives a value corresponding to the wafer pitch distance. The value corresponding to the wafer spacing distance is a value derived from the difference between the wafer spacing distance and the design value. For example, when the wafer spacing distance is 39mm smaller than the design value, that is, 40mm, the +1mm obtained by subtracting 39mm from 40mm becomes a value corresponding to the wafer spacing distance. When the wafer spacing distance is 41mm larger than the design value, that is, 40mm, the value corresponding to the wafer spacing distance is-1 mm obtained by subtracting 41mm from 40 mm. The nozzle setting unit 102 subtracts the above-described value corresponding to the wafer pitch distance from the downward movement amount from the Z-axis home position at the time of the design value, and thereby determines a third movement amount D (see fig. 10) which is the movement amount of the driving unit 30 when the wafer sensor 50 is located at the position 40mm directly above the wafer W (the downward movement amount from the Z-axis home position). The third movement amount D is a value corresponding to the wafer spacing distance, which is a measurement value actually measured by the wafer sensor 50.

The nozzle setting unit 102 determines a fourth movement amount E, which is a movement amount of the driving unit 30 for setting the nozzle 40 to a predetermined nozzle height, based on the mounting difference C and the third movement amount D which are derived by the mounting difference deriving unit 101, and controls the driving unit 30 such that the movement amount of the driving unit 30 is the fourth movement amount E (see fig. 12). The predetermined nozzle height (GAP) is a suitable height for spiral coating (described in detail later) of the nozzle 40, and is, for example, 50 μm or the like. The fourth movement amount E of the driving unit 30 is derived from the following equation, for example.

Fourth movement amount e= (40 mm (design value) +third movement amount D) - (installation difference C) -50 μm (GAP)

The coating control unit 103 controls the discharge of the coating liquid onto the wafer W by the nozzle 40 adjusted to the nozzle height (height of 50 μm from the wafer W) defined by the nozzle setting unit 102. The coating control unit 103 controls the rotation unit 21 to rotate the wafer W at a predetermined rotation speed. The coating control unit 103 controls the driving unit 30 so that the nozzle 40 is moved in a predetermined direction (horizontal direction) along the surface of the wafer W between the rotation axis and the peripheral edge of the wafer W in a state where the wafer W has been rotated. The coating control unit 103 controls a pump and a valve (both not shown) for feeding the coating liquid to the nozzle 40 so that the coating liquid is discharged from a discharge port of the front end 41 of the nozzle 40 that moves along the surface of the wafer W. That is, the coating control unit 103 controls the on/off of the coating liquid from the nozzle 40. In this way, when the nozzle 40 moves in the horizontal direction on the surface of the wafer W in a state where the wafer W has been rotated and the coating liquid is discharged from the nozzle 40 to the surface of the wafer W, the coating liquid is spirally applied to the surface of the wafer W as shown in fig. 14 (e).

The cleaning control unit 104 controls the cleaning unit 70 to clean the nozzle 40 based on the state of the coating liquid at the tip end 41 of the nozzle 40 detected by the nozzle sensor 60. For example, when the distance between the nozzle sensor 60 and the nozzle 40 detected by the nozzle sensor 60 after the application of the nozzle 40 is smaller than that in the normal state (smaller than the allowable range), the cleaning control unit 104 determines that the tip 41 is contaminated with the application liquid, and determines to clean the nozzle 40 by the cleaning unit 70. At this time, the cleaning control unit 104 controls the driving unit 30 so that the coated nozzle 40 is accommodated in the cleaning chamber 71 of the cleaning unit 70. Then, the cleaning control unit 104 controls a cleaning liquid supply unit (not shown) to supply the cleaning liquid into the cleaning chamber 71. The cleaning control unit 104 controls the driving unit 30 so that the nozzle 40 is disposed at the original storage position when the cleaning is completed.

(liquid treatment sequence)

Next, as an example of the substrate processing method, a liquid processing sequence executed by the controller 100 will be described. As shown in fig. 13, the controller 100 first performs step S1. Step S1 includes a mounting difference derivation process of measuring (deriving) a mounting difference between the wafer sensor 50 and the nozzle 40. The more detailed processing sequence is described later. Next, the controller 100 performs step S3. Step S3 includes a nozzle height adjustment process of adjusting the nozzle 40 to a predetermined nozzle height. The more detailed processing sequence is described later. Next, the controller 100 performs step S5. Step S5 includes a coating process of discharging a coating liquid from the nozzle 40 adjusted to the height of the discharge nozzle to the wafer W. The controller 100 may perform the cleaning control of the cleaning control unit 104 after step S5.

A series of flow paths of the liquid treatment sequence of the steps S1 to S5 are shown in fig. 14. As shown in fig. 14 (a), in the mounting difference derivation process of step S1, a sensor distance, which is a distance between the nozzle sensor 60 and the wafer sensor 50, is measured, and a nozzle distance, which is a distance between the nozzle sensor 60 and the tip 41 of the nozzle 40, is measured, and a mounting difference between the wafer sensor 50 and the nozzle 40 is derived based on the sensor distance and the nozzle distance. As shown in fig. 14 b and 14 c, in the discharge nozzle height adjustment process of step S3, the distance between the wafer sensor 50 and the wafer W is measured (see fig. 14 b), and the distance between the wafer W and the tip portion 41 of the nozzle 40 is adjusted to a predetermined discharge nozzle height based on the distance from the wafer W and the mounting difference (see fig. 14 c). The processing shown in fig. 14 (a) to 14 (c) is processing concerning the advance operation.

Then, as shown in fig. 14 (d) to (f), in the coating process of step S5, the discharge of the coating liquid from the nozzle 40 is started in a state in which the wafer W has rotated (see fig. 14 (d)), and the nozzle 40 is moved in the horizontal direction between the rotation axis and the peripheral edge of the wafer W, whereby the coating liquid is spirally applied to the surface of the wafer W (see fig. 14 (e)), and the coating film R is formed on the entire surface of the wafer W (see fig. 14 (f)). The processing shown in fig. 14 (d) to (f) is processing concerning a spiral coating operation.

(installation Difference derivation processing order)

Next, a detailed processing procedure of the installation difference derivation processing in step S1 will be described. As shown in fig. 15, the controller 100 first performs step S11. In step S11, the mounting-difference deriving unit 101 controls the driving unit 30 so that the wafer sensor 50 moves to a position 40mm (design value) directly above the nozzle sensor 60. The driving unit 30 moves the arm 31 downward by a predetermined amount (design value) from the Z-axis home position under the control of the mounting difference deriving unit 101.

Next, the controller 100 performs step S12. In step S12, the mounting difference deriving unit 101 controls the driving unit 30, and the nozzle sensor 60 measures the distance between the wafer sensor 50 and the horizontal direction both ends. The driving unit 30 moves the wafer sensor 50 in the left-right direction while maintaining the height in the up-down direction under the control of the mounting-difference deriving unit 101. The mounting difference deriving unit 101 obtains the distance from the nozzle sensor 60 between the two end portions of the wafer sensor 50 from the nozzle sensor 60.

Next, the controller 100 performs step S13. In step S13, the mounting difference deriving unit 101 determines the shorter one of the obtained distance between the two end portions as the sensor distance (measured value).

Next, the controller 100 performs step S14. In step S14, the mounting difference deriving unit 101 subtracts a value corresponding to the sensor distance as a measured value from the amount of movement of step S11 (the amount of movement of the driving unit 30 from the Z-axis home position corresponding to the design value). The value corresponding to the sensor separation distance is a value derived from the difference between the sensor separation distance and the design value (40 mm).

Next, the controller 100 performs step S15. In step S15, the mounting difference deriving unit 101 determines the value derived by the subtraction in step S14 as a first movement amount a (movement amount from the Z-axis home position to the lower side) which is the movement amount of the driving unit 30 when the wafer sensor 50 is positioned 40mm directly above the nozzle sensor 60 (see fig. 6).

Next, the controller 100 performs step S16. In step S16, the mounting difference deriving unit 101 controls the driving unit 30 so that the tip portion 41 of the nozzle 40 moves to a position 40mm (design value) directly above the nozzle sensor 60. The driving unit 30 moves the arm 31 downward by a predetermined amount (design value) from the Z-axis home position under the control of the mounting difference deriving unit 101.

Next, the controller 100 performs step S17. In step S17, the mounting difference deriving unit 101 controls the driving unit 30, and the distance to the tip end 41 of the nozzle 40 is measured at a plurality of positions by the nozzle sensor 60. The driving unit 30 scans the nozzle 40 in the left-right direction with respect to the nozzle sensor 60 while maintaining the height in the up-down direction under the control of the mounting difference deriving unit 101. In this state, the mounting difference deriving unit 101 obtains the distance between the wafer sensor 50 and the nozzle sensor 60 from the nozzle sensor 60 at predetermined time intervals (for example, every 100 ms), for example.

Next, the controller 100 performs step S18. In step S18, the mounting difference deriving unit 101 determines the shortest one of the acquired plurality of separation distances as the nozzle separation distance (measurement value).

Next, the controller 100 performs step S19. In step S19, the mounting difference deriving unit 101 subtracts a value corresponding to the nozzle interval distance as the measured value from the amount of movement of step S16 (the amount of movement of the driving unit 30 from the Z-axis home position corresponding to the design value). The value corresponding to the nozzle spacing distance is a value derived from the difference between the nozzle spacing distance and the design value (40 mm).

Next, the controller 100 performs step S20. In step S20, the mounting difference deriving unit 101 determines the value derived by the subtraction in step S19 as a second movement amount B (see fig. 7) which is a movement amount of the driving unit 30 (a movement amount from the Z-axis home position to the lower side) when the tip portion 41 of the nozzle 40 is located at a position 40mm directly above the nozzle sensor 60.

Next, the controller 100 performs step S21. In step S21, the mounting difference deriving unit 101 subtracts the second movement amount B from the first movement amount a to determine a mounting difference C between the wafer sensor 50 and the nozzle 40 (see fig. 9). Through the above processing, the installation difference derivation processing is completed.

(discharge nozzle height adjustment processing sequence)

Next, a detailed process sequence of the nozzle height adjustment process in step S3 will be described. As shown in fig. 16, the controller 100 first performs step S31. In step S31, the nozzle setting unit 102 controls the driving unit 30 so that the wafer sensor 50 moves to a position 40mm (design value) right above the wafer W. The driving unit 30 moves the arm 31 downward from the Z-axis home position by a predetermined movement amount (design value) under the control of the nozzle setting unit 102.

Next, the controller 100 performs step S32. In step S32, the nozzle setting unit 102 controls the driving unit 30 to measure the distance between the wafer sensor 50 and the wafer W at a plurality of positions by the wafer sensor 50. The driving unit 30 scans the wafer sensor 50 in the left-right direction with respect to the wafer W while maintaining the height in the up-down direction under the control of the nozzle setting unit 102. In this state, the nozzle setting unit 102 obtains the distance from the wafer W from the wafer sensor 50 at predetermined time intervals (for example, every 100 ms), for example.

Next, the controller 100 performs step S33. In step S33, the nozzle setting unit 102 determines the shortest one of the acquired plurality of separation distances as the wafer separation distance (measurement value).

Next, the controller 100 performs step S34. In step S34, the nozzle setting unit 102 subtracts a value corresponding to the wafer pitch distance, which is a measured value, from the movement amount of step S31 (the movement amount of the driving unit 30 from the Z-axis home position, which corresponds to the design value). The value corresponding to the wafer spacing distance is a value derived from the difference between the wafer spacing distance and the design value (40 mm).

Next, the controller 100 performs step S35. In step S35, the nozzle setting unit 102 determines the value derived from the subtraction in step S34 as a third movement amount D (see fig. 10) which is a movement amount of the driving unit 30 when the wafer sensor 50 is located at a position 40mm directly above the wafer W (a movement amount from the Z-axis home position to the lower side).

Next, the controller 100 performs step S36. In step S36, the nozzle setting unit 102 determines a fourth movement amount E, which is a movement amount of the driving unit 30 that sets the nozzle 40 to a predetermined nozzle height (for example, 50 μm), based on the mounting difference C and the third movement amount D that are derived by the mounting difference deriving unit 101.

Next, the controller 100 performs step S37. In step S37, the nozzle setting unit 102 controls the driving unit 30 so that the movement amount of the driving unit 30 becomes the fourth movement amount E (see fig. 12). Through the above processing, the discharge nozzle height adjustment processing is completed.

In addition, although a series of processes of the liquid treatment sequence is described above, each treatment is not necessarily performed in groups each time. For example, the processes of steps S11 to S15 for determining the first movement amount a may be performed at the time of starting the apparatus, the processes of steps S16 to S21 for determining the second movement amount B and the mounting difference C may be performed at the time of starting the apparatus and switching the nozzles, and the processes of steps S31 to S36 for determining the third movement amount D and the fourth movement amount E may be performed for each wafer W.

(effects of the first embodiment)

As described above, the liquid processing unit U1 of the first embodiment includes: a holding section 23 for holding the wafer W; a nozzle 40 for discharging the coating liquid from the front end 41 toward the wafer W held by the holding portion 23; a driving unit 30 for moving the nozzle 40 above the wafer W; and a nozzle sensor 60 that detects the state of the front end 41 of the nozzle 40 moved by the driving section 30.

In such a liquid processing unit U1, the state of the front end portion 41 of the nozzle 40 moved by the driving portion 30 is detected by the nozzle sensor 60. This makes it possible to obtain information such as the distance between the nozzle 40 and the nozzle 40, the levelness of the tip 41 of the nozzle 40, or the state of the coating liquid fixed to the tip 41, and to appropriately set the gap between the nozzle 40 and the wafer W at the time of discharging the coating liquid by using the information. As described above, according to the liquid processing unit U1, the gap between the nozzle 40 and the wafer W can be adjusted with high accuracy.

The nozzle sensor 60 is disposed below the movement path of the nozzle 40 moved by the driving unit 30. The nozzle 40 moved by the driving unit 30 discharges the coating liquid from above the wafer W (i.e., from the lower portion of the nozzle 40, i.e., the front end 41), and the nozzle sensor 60 is disposed below the movement path of the nozzle 40, so that the state of the front end 41 of the nozzle 40 can be detected well by the nozzle sensor 60. That is, the gap between the nozzle 40 and the wafer W can be adjusted with higher accuracy.

The driving unit 30 moves the nozzle 40 to scan the nozzle 40 with respect to the nozzle sensor 60, and the nozzle sensor 60 detects the states of the plurality of portions of the distal end portion 41. It is difficult to completely flatten the front end 41 of the nozzle 40, and irregularities of the order of several tens of μm may occur between the regions of the front end 41. By detecting the states of the plurality of portions of the front end portion 41 by the nozzle sensor 60 by the scanning operation, the gap between the nozzle 40 and the wafer W can be set in consideration of the irregularities.

The liquid processing unit U1 has a plurality of nozzles 40, and the driving unit 30 selects at least 1 nozzle 40 from the plurality of nozzles 40, and moves the selected nozzle 40 upward of the wafer W through the detection range of the nozzle sensor 60. Thus, for example, the nozzles 40 can be prepared for each coating liquid, and the gap between the nozzle 40 and the wafer W can be set for each nozzle 40. Further, since the gap between the nozzle 40 and the wafer W can be set every time the nozzle 40 is replaced, the gap can be adjusted with higher accuracy. In addition, when a plurality of nozzles 40 are used, it is not necessary to prepare a sensor for each nozzle, and therefore the structure can be simplified.

The liquid processing unit U1 further includes a wafer sensor 50 for detecting a distance from the wafer W, and the driving unit 30 includes an arm 31 for holding the nozzle 40 and the wafer sensor 50, and moves the nozzle 40 and the wafer sensor 50 by the arm 31. This allows the wafer sensor 50 held by the arm 31 together with the nozzle 40 to detect the distance from the wafer W. That is, the distance between the nozzle 40 and the wafer W can be appropriately determined, and the gap between the nozzle 40 and the wafer W can be adjusted with higher accuracy.

The nozzle sensor 60 is configured to be able to detect the distance from the nozzle 40 and the distance from the wafer sensor 50, the wafer sensor 50 is configured to be able to detect the distance from the nozzle sensor 60, and the controller 100 is configured to perform the following processing: obtaining a sensor separation distance, which is a separation distance between the nozzle sensor 60 and the wafer sensor 50, from at least either one of the nozzle sensor 60 and the wafer sensor 50; a nozzle interval distance, which is a distance between the nozzle sensor 60 and the nozzle 40, is obtained from the nozzle sensor 60; and deriving a mounting difference of the wafer sensor 50 and the nozzle 40 based on the sensor spacing distance and the nozzle spacing distance. By deriving the mounting difference, which is the difference between the mounting positions of the wafer sensor 50 and the nozzle 40, the distance between the nozzle 40 and the wafer W can be determined with high accuracy based on the detection result of the wafer sensor 50. This enables the gap between the nozzle 40 and the wafer W to be adjusted with higher accuracy.

The controller 100 is configured to also perform the following processing: obtaining a separation distance from the wafer W from the wafer sensor 50; and controlling the driving unit 30 so that the distance between the wafer W and the nozzle 40 derived based on the distance from the wafer W and the mounting difference obtained from the wafer sensor 50 becomes a predetermined discharge nozzle height. Accordingly, the gap between the nozzle 40 and the wafer W can be appropriately adjusted in consideration of the mounting difference, and the nozzle 40 can be set to a predetermined nozzle height.

The liquid processing unit U1 has a cleaning portion 70 for cleaning the nozzle 40 with a cleaning liquid, the nozzle sensor 60 detects the state of the coating liquid of the front end portion 41, and the controller 100 is configured to further execute the following processing: the cleaning section 70 is controlled to clean the nozzle 40 based on the state of the coating liquid at the tip 41 detected by the nozzle sensor 60. Thus, for example, when the gap between the nozzle 40 and the wafer W is affected by the coating liquid fixed to the front end 41, the cleaning of the cleaning section 70 can be performed. This enables the gap between the nozzle 40 and the wafer W to be adjusted with higher accuracy, and can appropriately suppress the change in the film thickness due to contamination of the front end 41.

Second embodiment

Next, a liquid treatment unit according to a second embodiment will be described with reference to fig. 17 to 26. In the description of the present embodiment, differences from the first embodiment will be mainly described.

The liquid treatment unit of the second embodiment has a structure for eliminating contamination of the tip end portion of the nozzle caused by the spiral coating. First, a problem of contamination of the nozzle tip portion at the time of spiral coating will be described with reference to fig. 17 to 22.

As shown in fig. 17 (a), when spiral coating is performed, the distance between the tip 141 of the nozzle 140 and the wafer W must be made short (for example, 50 μm). When the coating liquid 180 is applied from such a liquid contact type nozzle 140, as shown in fig. 17 (b), not only the discharge port 142 but also the entire front end portion 141 (liquid contact portion) is contaminated with the coating liquid 180. Since the coating liquid 180 applied by the liquid contact type nozzle has a high viscosity (500 to 7000 cp), it is difficult to keep the tip 141 of the nozzle 140 in a clean state after the application.

Here, after the front end portion 141 shown in fig. 18 (b) is contaminated from the state of the coating completion shown in fig. 18 (a), as shown in fig. 18 (c) and 18 (d), a bubble portion 181 may be generated in the coating liquid 180. In this state, if the back suction is performed, the coating liquid 180 is a high viscosity liquid, and as shown in fig. 18 (e), the bubble portion 181 is embedded in the nozzle 140, and the liquid surface of the coating liquid 180 cannot be kept high. Thus, even if the suction is performed, the tip 141 of the nozzle 140 is contaminated with the coating liquid 180.

When the cleaning liquid 190 such as a diluent (water for containment) is used to clean the tip 141 of the nozzle 140 in a contaminated state as shown in fig. 19 (a), the tip 141 is visually observed to be cleaned as shown in fig. 19 (b). However, since the coating liquid 180 is in contact with the cleaning liquid 190 at the tip 141, as shown in fig. 19 (c) to 19 (e), the mixed liquid 191 in which the coating liquid 180 and the cleaning liquid 190 are mixed intrudes into the nozzle 140.

Further, as time passes, the mixed liquid 191 that has entered the nozzle 140 dissolves out into the cleaning liquid 190 as shown in fig. 20 (a), and as a result, the tip 141 of the nozzle 140 is covered with the contaminated liquid 195 as shown in fig. 20 (b). The contaminated liquid 195 is dried and cured, whereby a cured film 196 is formed at the tip portion 141 (see fig. 20 c). Since such a cured film 196 is formed, the gap between the front end portion 141 and the wafer W may be changed, which may affect the thickness of the spiral coating film.

Further, since the mixed liquid 191 (the liquid obtained by mixing the coating liquid 180 and the cleaning liquid 190) which has entered the inside of the nozzle 140 shown in fig. 21 (a) is discharged to the wafer W at the time of coating as shown in fig. 21 (b), a liquid having a low concentration (a liquid having a lower concentration than the coating liquid 180) is discharged to the wafer W. This affects the film thickness. As shown by the broken line in fig. 22, when the cleaning liquid such as the diluent enters the nozzle 140 and the mixed liquid 191 is discharged, a large variation in the formed film thickness occurs depending on the position of the wafer W (the variation in the formed film thickness becomes larger than in the normal case shown by the solid line in fig. 22).

In order to solve the above problems, the liquid treatment unit according to the second embodiment employs a structure in which the cleaning liquid is dried by air blowing and removed, thereby suppressing mixing of the coating liquid and the cleaning liquid. That is, as shown in fig. 23 (a), after the tip portion 41 is washed with the washing liquid 190, the washing liquid 190 is dried by bringing air into contact with the washing liquid 190 attached to the tip portion 41 before the washing liquid 190 and the coating liquid are mixed. As a result, as shown in fig. 23 (b), the cleaning liquid 190 can be removed, and the cleaning liquid 190 and the coating liquid can be prevented from being mixed. This can keep the front end 41 clean, and effectively suppress the variation in the film thickness.

The liquid treatment unit of the second embodiment specifically includes a cleaning section 70A and a controller 100A shown in fig. 24. The cleaning unit 70A is configured to clean the nozzle 40 with a cleaning liquid. The cleaning portion 70A has a cleaning chamber 71A that houses the nozzle 40. Further, the cleaning section 70A includes a cleaning liquid supply section 72A and a blower section 73A (cleaning liquid removal section).

The cleaning liquid supply unit 72A is configured to supply the cleaning liquid 190 to the cleaning chamber 71A under the control of the cleaning control unit 104A of the controller 100A. The cleaning liquid supply portion 72A supplies the cleaning liquid 190 into the cleaning chamber 71A in a state where the nozzle 40 from which the coating liquid is discharged is stored in the cleaning chamber 71A, for example, to form a vortex of the cleaning liquid 190, thereby cleaning the tip end 41 of the nozzle 40.

The blower 73A has the following structure: by blowing air to the cleaning liquid 190 attached to the distal end portion 41 under the control of the cleaning control unit 104A of the controller 100A, the cleaning liquid 190 is dried, and the cleaning liquid 190 is removed from the distal end portion 41. The blower 73A feeds air into the cleaning chamber 71A, thereby blowing air into the cleaning liquid 190 at the front end 41 of the nozzle 40.

The cleaning unit 70A has a blowing mechanism 75a (see fig. 25 (a)) as a structure for properly contacting the air fed from the blowing unit 73A into the cleaning chamber 71A with the cleaning liquid 190 at the front end portion 41. The blower mechanism 75a is provided in the cleaning chamber 71A, and is configured to effectively blow air toward the front end 41 of the nozzle 40 disposed at the nozzle installation position 79A.

As shown in fig. 25 (a), the blower mechanism 75a includes an air pipe 76A and an air guide 77a. The air pipe 76A is a pipe for sending the air sent from the blower 73A to the air guide 77a. The air guide 77a is an annular member. The nozzle installation position 79A is formed inside the air guide 77a. The air sent from the air pipe 76A rotates along the outer edge of the air guide 77a. The air guide portion 77a has notch portions 78a formed at 2 positions (2 positions opposed to each other in the radial direction). By forming the notch 78a, air flowing on the outer edge of the air guide 77a flows from the notch 78a toward the nozzle mounting position 79A. The air flowing in from the notch 78a rotates along the inner edge of the air guide 77a. This allows air to be blown in a rotating manner to the cleaning liquid 190 at the front end 41 of the nozzle 40 disposed at the nozzle installation position 79A, and the cleaning liquid 190 at the front end 41 can be dried without omission.

The cleaning unit 70A may have a blower mechanism 75b shown in fig. 25 (b) instead of the blower mechanism 75 a. The blowing mechanism 75b has an air guide 77b in place of the air guide 77 a. The air guide 77b is an annular member. An opening 78b is formed in the air guide 77b at the inflow portion of the air sent from the air pipe 76A. By forming the opening 78b, the air fed from the air pipe 76A flows linearly from the opening 78b into the nozzle installation position 79A. As a result, air can be blown linearly (in a band shape) onto the cleaning liquid 190 at the front end 41 of the nozzle 40 disposed at the nozzle installation position 79A, and the cleaning liquid 190 at the front end 41 can be dried by powerful air.

The cleaning unit 70A may have a blower mechanism 75c shown in fig. 25 (c) instead of the blower mechanisms 75a and 75b. The blower mechanism 75c has an air guide 77c in place of the air guides 77a and 77b. The air guide 77c is an annular member. The 6 notched portions 78c are formed at regular intervals in the circumferential direction in the air guide portion 77c. By forming the notch 78c, air flowing on the outer edge of the air guide 77c flows from the notch 78c toward the nozzle installation position 79A. By blowing air from the notch portions 78c formed at regular intervals in the circumferential direction, the cleaning liquid 190 can be blown from a plurality of directions, and the cleaning liquid 190 at the tip portion 41 can be dried without omission.

(cleaning treatment sequence)

Next, as an example of the substrate processing method, a liquid processing sequence executed by the controller 100A will be described. As shown in fig. 26, the controller 100A first performs step S7. In step S7, the cleaning control unit 104A controls the driving unit 30 to store the nozzle 40 in the cleaning chamber 71A.

Next, the controller 100A performs step S8. In step S8, the cleaning control unit 104A controls the cleaning liquid supply unit 72A to supply the cleaning liquid 190 (diluent) to the front end portion 41 of the nozzle 40 in the cleaning chamber 71A.

Next, the controller 100A performs step S9. In step S9, the cleaning control unit 104A controls the blower 73A to blow air to the tip 41 of the nozzle 40. The air blown by the blower 73A is blown to the cleaning liquid 190 at the front end 41 of the nozzle 40 via the blower 75a (or the blower 75b or the blower 75 c). Thereby, the cleaning liquid 190 is dried, and the cleaning liquid 190 can be removed from the distal end portion 41.

(modification)

The present embodiment has been described above, but the present invention is not limited to the above embodiment. For example, the blower 73A is illustrated as the cleaning liquid removing portion, but the cleaning liquid removing portion is not limited to this, and may be the structure illustrated in fig. 27 and 28.

As an example of the cleaning section 70B shown in fig. 27, an absorbing section 73B is provided as a cleaning liquid removing section that removes the cleaning liquid 190 adhering to the tip end 41 of the nozzle 40. The absorbing portion 73B is a member that absorbs the cleaning liquid 190 remaining in the front end portion 41 by being pressed by the front end portion 41. The absorbing portion 73B is a plate made of a sponge-like synthetic resin such as PVA (polyvinyl alcohol ). As shown in fig. 27 (a), first, the nozzle 40 cleaned by the cleaning liquid 190 is disposed immediately above the absorbing portion 73B, and as shown in fig. 27 (B), the tip 41 of the nozzle 40 is pressed against the absorbing portion 73B. As a result, as shown in fig. 27 (c), the cleaning liquid 190 remaining at the distal end portion 41 is absorbed by the absorbing portion 73B. The absorbing portion 73B that absorbs the cleaning liquid 190 can be reused after being washed with a diluent and naturally dried, for example.

The cleaning section 70C shown in fig. 28 includes a water supply section 73C as an example of the cleaning liquid removal section (see fig. 28 (b)). The water supply portion 73C forms a water film at the front end 41 by supplying water to the front end 41. As shown in fig. 28 (b), water is supplied from the water supply portion 73C to the tip portion 41 of the nozzle 40 to which the cleaning liquid 190 is attached as shown in fig. 28 (a). Thereby, the cleaning liquid is replaced with water, and a water film 250 is formed at the tip 41. In this state, the liquid surface is raised by suction back as shown in fig. 28 (c), and the distal end portion 41 is pressed against the absorbing portion 73B as shown in fig. 28 (d). As a result, as shown in fig. 28 (e), excess water at the distal end 41 can be removed. In addition, in the case where water cannot be sufficiently absorbed even by the absorbing portion 73B, air blowing or the like can be performed. Since the water film 250 covers the discharge port, elution of liquid, drying, and contamination of the nozzle can be suppressed. Further, water and oil are separated, so that penetration of water into the nozzle 40 can be suppressed.

Claims (4)

1. A substrate processing apparatus, comprising:

a holding section for holding the substrate;

at least 1 liquid contact type discharge nozzle for discharging coating liquid from front end to the substrate held by the holding part;

A driving part for moving the discharge nozzle to the upper part of the substrate;

a first sensor for detecting a state of the tip portion of the discharge nozzle moved by the driving unit, the tip portion including a liquid contact surface facing a surface of the substrate, the first sensor being a displacement sensor for deriving a distance from an object by acquiring wavelength information of reflected light from the object;

a second sensor for detecting a separation distance from the substrate; and

the control part is used for controlling the control part to control the control part,

the driving part moves the discharge nozzle so that the state of a plurality of parts of the front end part can be detected by the first sensor,

the driving part has an arm part for holding the discharge nozzle and the second sensor, the arm part moves the discharge nozzle and the second sensor,

the driving part moves the second sensor to the upper side of the substrate through the detection range of the first sensor,

the first sensor is disposed below a moving path of the discharge nozzle moved by the driving unit, detects a distance between the plurality of portions of the tip portion of the discharge nozzle,

the control section performs the following processing:

Obtaining a sensor separation distance, which is a separation distance between the first sensor and the second sensor, from at least either one of the first sensor and the second sensor;

obtaining a nozzle interval distance, which is a distance between the first sensor and the discharge nozzle, from the first sensor;

deriving a difference in mounting position of the second sensor and the discharge nozzle based on the sensor spacing distance and the nozzle spacing distance;

acquiring a separation distance from the substrate from the second sensor; and

the driving unit is controlled so that a distance between the substrate and the discharge nozzle becomes a predetermined discharge nozzle height, and the distance between the substrate and the discharge nozzle is derived based on a difference between the distance from the substrate obtained from the second sensor and the mounting position.

2. The substrate processing apparatus of claim 1, wherein:

there is a plurality of said discharge nozzles,

the driving unit selects at least 1 of the discharge nozzles from the plurality of discharge nozzles, and moves the selected discharge nozzle upward of the substrate through a detection range of the first sensor.

3. The substrate processing apparatus according to claim 1 or 2, wherein:

And a cleaning part for cleaning the discharge nozzle by using cleaning liquid,

the control section also performs the following processing:

the cleaning unit is controlled so as to clean the discharge nozzle in accordance with the state of the front end portion detected by the first sensor.

4. A substrate processing apparatus according to claim 3, wherein:

the cleaning part further includes:

a cleaning liquid supply unit for supplying the cleaning liquid; and

and a cleaning liquid removing section for removing the cleaning liquid adhering to the tip portion of the discharge nozzle after the cleaning liquid is supplied.

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