JP6993273B2 - Board processing equipment and board processing method - Google Patents

Description

The present invention relates to a substrate processing apparatus and a substrate processing method for forming a film with a coating liquid on a main surface of a substrate, and particularly to a technique for measuring the film thickness thereof. The above-mentioned substrates include a semiconductor substrate, a photomask substrate, a liquid crystal display substrate, an organic EL display substrate, a plasma display substrate, a FED (Field Emission Display) substrate, an optical disk substrate, a magnetic disk substrate, and an optical disk. Includes boards for magnetic disks.

In the manufacturing process of electronic components such as semiconductor devices and liquid crystal displays, it is widely practiced to apply a liquid containing a film forming material to the main surface of a substrate to form a film. For example, such a film formation is carried out for the purpose of forming a resist film, an insulating film, a protective film and the like on the main surface of the substrate. Some coating devices of this type are provided with a mechanism for measuring the film thickness immediately after formation, for example, in order to confirm the state of the film and optimize the film forming conditions.

For example, in the technique described in Patent Document 1, the film thickness is obtained by measuring the surface height of the base material before forming the coating film and subtracting the surface height of the base material from the surface height after the film formation. .. Further, in the technique described in Patent Document 2, optical sensors are provided in front of and behind the nozzle that scans and moves with respect to the base material, and the height of the base material surface detected by the optical sensor on the front side of the nozzle and the optical sensor on the rear side of the nozzle are determined. The film thickness is obtained as the difference from the height of the film surface to be detected.

Japanese Unexamined Patent Publication No. 2011-255260 Japanese Unexamined Patent Publication No. 2006-181566

The surface height of the substrate and the thickness of the film are not always constant and vary from position to position. Therefore, the method of simply taking the difference between the height of the film surface and the height of the substrate as in the above-mentioned conventional technique can obtain the average film thickness, but cannot accurately detect the film thickness at each position. There is a problem.

In addition, 100% inspection may be required to ensure the quality of the film after coating, and in this case, it is necessary to measure the film thickness without affecting the productivity of film formation. However, in the technique described in Patent Document 1, the surface height of the base material is first measured by the relative movement between the base material and the height detector, and then the relative movement is executed again from the original position to execute the relative movement to the surface height of the film. It is necessary to measure the height. Since this reduces the productivity of film formation, it cannot be incorporated into a continuous film formation process.

The present invention has been made in view of the above problems, and in a substrate processing apparatus and a substrate processing method for forming a film with a coating liquid on the main surface of a substrate, the film thickness at each position can be accurately measured. It is an object of the present invention to provide a film thickness measurement technology that can be incorporated into a membrane process.

One aspect of the present invention is a substrate processing apparatus that discharges a fluid to the main surface of the substrate, and is a slit-shaped substrate processing apparatus that forms a film of a coating liquid on the main surface of the substrate in order to achieve the above object. A nozzle that moves relative to the substrate while discharging the coating liquid from the discharge port to apply the coating liquid to the main surface to form the film, and a nozzle that faces the main surface and reaches the main surface. The distance measuring unit that measures the first distance and the second distance to the surface of the film coated on the main surface, and the distance measuring unit integrated with the nozzle in the moving direction along the main surface. At the moving unit that moves relative to the substrate , the position detecting unit that detects the position of the distance measuring unit with respect to the substrate in the moving direction, and the position and the position of the distance measuring unit detected by the position detecting unit. The first information associated with the first distance measured by the distance measuring unit, and the position of the distance measuring unit detected by the position detecting unit and the second distance measured by the distance measuring unit at the position. The information acquisition unit that acquires the second information associated with the above, and the first distance and the said when the positions of the distance measuring unit with respect to the substrate are the same based on the first information and the second information. It is provided with a film thickness calculation unit that calculates the thickness of the film corresponding to the position from the difference from the second distance, and the nozzle moves relative to the substrate from a predetermined movement start position in one direction. After applying the coating liquid to the main surface, the coating liquid moves relative to the substrate in a direction opposite to the one direction and at a relative speed faster than the relative movement in the one direction to the movement start position. The distance measuring unit is arranged in front of the nozzle in the one direction, and is different from each other along the relative movement direction when relatively moving in the one direction with respect to the main surface before application of the coating liquid. The first distance is measured at a plurality of positions, and the second distance is measured at a plurality of different positions along the relative movement direction when the main surface after coating moves relative to the main surface in the opposite direction. The thickness calculation unit includes position detection by the position detection unit and distance measurement by the distance measurement unit according to the relative movement speed in the relative movement of the distance measurement unit in the one direction and the opposite direction with respect to the substrate. Correct the misalignment caused by the response time between .

Further, in another aspect of the present invention, the nozzle for discharging the coating liquid from the slit-shaped discharge port is relatively moved with respect to the substrate, and the coating liquid is applied to the main surface of the substrate to apply the coating liquid. It is a substrate processing method for forming a film, and in order to achieve the above object, a distance measuring portion arranged facing the main surface is integrated with the nozzle in a moving direction along the main surface with respect to the substrate. By moving relative to each other, the position of the distance measuring unit with respect to the substrate in the moving direction is detected by the position detecting unit, and the distance measuring unit is the first distance to the main surface and the film coated on the main surface. The first information obtained by measuring the second distance to the surface and associating the position of the distance measuring unit detected by the position detecting unit with the first distance measured by the distance measuring unit at the position, and the above. The second information corresponding to the position of the distance measuring unit detected by the position detecting unit and the second distance measured by the distance measuring unit at the position is acquired, and the film thickness detecting unit obtains the first information and the first information. Based on the second information, the thickness of the film corresponding to the position is calculated from the difference between the first distance and the second distance when the positions of the distance measuring portions with respect to the substrate are the same as each other. The nozzle moves relative to the substrate in one direction from a predetermined movement start position, applies the coating liquid to the main surface, and then moves in the direction opposite to the one direction with respect to the substrate and said. It moves relative to the movement start position at a relative speed faster than the relative movement in one direction, and the distance measuring unit is arranged in front of the nozzle in the one direction, and the main body before the application of the coating liquid is applied. When the first distance is measured at a plurality of different positions along the relative movement direction when moving relative to the surface in the one direction, and when the first distance is moved relative to the main surface after coating in the opposite direction. The second distance is measured at a plurality of positions different from each other along the relative movement direction, and the film thickness calculation unit moves relative to the substrate in the relative movement of the distance measuring unit in one direction and in the opposite direction. Depending on the speed, the position shift due to the response time between the position detection by the position detection unit and the distance measurement by the distance measuring unit is corrected .

In the invention configured as described above, the position of the distance measuring unit with respect to the substrate is detected in the relative movement between the substrate and the distance measuring unit. Based on the result, the first distance to the main surface measured by the distance measuring unit and the position of the distance measuring unit at that time are associated as the first information. Further, the second distance to the film surface measured by the distance measuring unit and the position of the distance measuring unit at that time are associated as the second information. Therefore, the first distance and the second distance measured at the same position can be associated with each other via the first information and the second information. Therefore, by obtaining these differences, it is possible to accurately obtain the thickness of the film at the position.

Since the measurement results of the first distance and the second distance are associated with the position of the distance measuring unit in this way, each measurement can be executed at individual timings. Therefore, it is possible to incorporate the film thickness measurement into the film formation process without affecting the film thickness tact time.

As described above, according to the present invention, since the position detection result of the distance measuring unit with respect to the substrate is associated with the distance to the main surface of the substrate and the surface of the film measured by the distance measuring unit, the same position is used. It is possible to accurately measure the film thickness for each position from the difference in distance, and it is possible to measure the film thickness during the film formation process without affecting the tact time of film formation. be.

It is a perspective view which shows the coating apparatus which is 1st Embodiment of the substrate processing apparatus of this invention. It is a side view which shows the main structure of this coating apparatus, and the outline of the operation. It is a figure which shows the structure of a height sensor. It is a block diagram which shows the electric structure of the control part of this image pickup apparatus. It is a figure which shows the coating operation by this coating apparatus. It is a flowchart which shows the operation of this coating apparatus. It is a figure which shows the principle of the film thickness calculation. It is a figure explaining the principle of correspondence to a response time. It is a side view which shows the main part of the 2nd Embodiment of the substrate processing apparatus which concerns on this invention.

FIG. 1 is a perspective view showing a coating device as a first embodiment of the substrate processing device according to the present invention. In addition, in order to clarify the directional relationship between FIGS. 1 and the following, an XYZ Cartesian coordinate system with the Z direction as the vertical direction and the XY plane as the horizontal plane is appropriately attached. Also, for the purpose of easy understanding, the dimensions and numbers of each part are exaggerated or simplified as necessary.

The coating device 1 is a coating device called a slit coater that applies a coating liquid to the surface of the substrate S using a slit nozzle 2. The coating device 1 can use various coating liquids such as a resist liquid, a color filter liquid, a polyimide, a polyimide precursor, silicon, nanometal ink, and a slurry containing a conductive material as the coating liquid. Further, the substrate S to be coated is also applied to various substrates such as a rectangular glass substrate, a semiconductor substrate, a flexible substrate for a film liquid crystal display, a substrate for a photomask, a substrate for a color filter, a substrate for a solar cell, and a substrate for an organic EL. It is possible. In particular, the coating device 1 is suitable for using a highly viscous liquid as the coating liquid. In the present specification, the “surface Sa of the substrate S” means the main surface of both main surfaces of the substrate S on the side to which the coating liquid is applied. As will be described later, in this coating device 1, the coating operation is performed with the substrate S placed on the horizontal stage 4, and the upper surface of the substrate S at that time corresponds to the surface Sa.

The coating device 1 includes a stage 4 capable of sucking and holding the substrate S in a horizontal position, a coating processing unit 5 for applying a coating process to the substrate S held by the stage 4 using a slit nozzle 2, and a slit prior to the coating process. A nozzle cleaning device that performs cleaning processing on the nozzle 2 (not shown), a pre-dispensing device that performs pre-dispensing treatment on the slit nozzle 2 prior to the coating process (not shown), and a control unit that controls each of these parts. It is equipped with 8.

The slit nozzle 2 has a discharge port which is a long opening extending in the X direction. Then, the slit nozzle 2 can discharge the coating liquid from the discharge port toward the surface Sa of the substrate S held by the stage 4.

The stage 4 is made of a stone material such as granite having a substantially rectangular parallelepiped shape, and the (−Y) side of the upper surface (+ Z side) is processed into a substantially horizontal flat surface to hold the substrate S. The surface 41 is provided. A large number of vacuum suction ports (not shown) are dispersedly formed on the holding surface 41. By sucking the substrate S by these vacuum suction ports, the substrate S is held in a substantially horizontal state at a predetermined position during the coating process. The holding mode of the substrate S is not limited to this, and may be configured to mechanically hold the substrate 3, for example.

In the coating device 1 of the present embodiment, a moving mechanism for moving the slit nozzle 2 in the Y direction is provided in the coating processing unit 5. The main configuration of the moving mechanism is a nozzle support 51 having a bridge structure that crosses the upper part of the stage 4 in the X direction and supports the slit nozzle 2, and the nozzle support 51 and the nozzle support 51 along a pair of guide rails 52 extending in the Y direction. It has a nozzle moving portion 53 that horizontally moves the slit nozzle 2 supported by the slit nozzle 2. The nozzle support 51 has a beam member 51a that supports the slit nozzle 2 with the X direction as the longitudinal direction, and a pair of pillar members 51b that each support the X-direction end of the beam member 51a.

A height sensor 6 is provided on the (−X) side side surface of the beam member 51a. As will be described in detail later, the height sensor 6 emits a light beam downward and receives the reflected light to measure the distance to the facing surface below the height sensor 6. For example, a known laser displacement meter can be applied as the height sensor 6.

As shown in FIG. 1, the nozzle support 51 configured in this way has a bridge structure in which the left and right ends of the stage 4 are hung along the X-axis direction and straddle the holding surface 41. The nozzle moving portion 53 relatively moves the nozzle support 51 as the crosslinked structure and the slit nozzle 2 fixedly held therein along the Y-axis direction with respect to the substrate S held on the stage 4. Functions as a means of transportation.

The nozzle moving unit 53 detects the positions of the guide rail 52 that guides the movement of the slit nozzle 2 in the Y-axis direction, the linear motor 54 that is the drive source, and the discharge port of the slit nozzle 2 on each of the ± X sides. It is equipped with a position sensor 55 for the purpose.

The two guide rails 52 are located at both ends of the stage 4 in the X-axis direction from the nozzle cleaning position (arrangement position of the nozzle cleaning device) to the coating end position (-Y side end portion of the holding surface 41) along the Y-axis direction. It is extended to include the section up to (position). Therefore, the lower ends of the two pillar members 51b are guided along the two guide rails 52 by the nozzle moving portion 53, so that the slit nozzle 2 is placed on the nozzle cleaning position and the substrate S held on the stage 4. Move between opposite positions.

In the present embodiment, each linear motor 54 is configured as an AC coreless linear motor having a stator 54a and a mover 54b. The stator 54a is provided on both side surfaces of the stage 4 in the X-axis direction along the Y-axis direction. On the other hand, the mover 54b is fixed to the outside of the elevating mechanism 51b. The linear motor 54 functions as a drive source for the nozzle moving portion 53 by the magnetic force generated between the stator 54a and the mover 54b.

Further, each position sensor 55 has a so-called linear encoder configuration, and has a scale unit 55a and a detection unit 55b, respectively. The scale portion 55a is provided in the lower portion of the stator 54a of the linear motor 54 fixed to the stage 4 along the Y-axis direction. On the other hand, the detection unit 55b is fixedly installed outside the mover 54b of the linear motor 54 fixed to the elevating mechanism 51b, and is arranged to face the scale unit 55a. The scale unit 55a is provided with grid scales at regular intervals, and each time the detection unit 55b that moves relative to the scale unit 55a reads the scale, a pulse signal is output from the detection unit 55. The output signal of the detection unit 55 is input to the control unit 8. As will be described later, the position of the discharge port of the slit nozzle 2 in the Y-axis direction is detected based on the relative positional relationship between the scale unit 55a and the detection unit 55b.

FIG. 2 is a side view showing an outline of the main configuration of this coating device and its operation. The beam member 51a of the nozzle support 51 is a channel-type structure having a substantially U-shaped cross section and having an opening facing downward. For example, the beam member 51a can be made of a metal such as stainless steel or a carbon fiber reinforced resin. The slit nozzle 2 is housed in the opening portion of the beam member 51a. More specifically, the slit nozzle 2 is attached to the beam member 51a via the nozzle elevating mechanism 22. The nozzle raising / lowering mechanism 22 raises / lowers the slit nozzle 2 in the vertical direction (Z direction). As a result, the slit nozzle 2 can move in the proximity direction and the separation direction with respect to the substrate S on the stage 4.

The lower end of the slit nozzle 2 faces the surface Sa of the substrate S on the stage 4, and a slit-shaped discharge port 21 having the X direction as the longitudinal direction is provided at the lower end. The distance between the discharge port 21 and the substrate S can be changed by raising and lowering the slit nozzle 2. The coating liquid is applied to the surface Sa of the substrate S by discharging the coating liquid from the discharge port 21 in a state where the discharge port 21 is arranged to face the surface Sa of the substrate S with a predetermined gap.

Further, the nozzle moving portion 53 moves the nozzle support 51 in the Y direction, so that the ejection port 21 of the slit nozzle 2 scans and moves along the surface Sa with respect to the substrate S, thereby moving to the surface Sa of the substrate S. A film F is formed by the coating liquid.

The detection unit 55b of the position sensor 55 moves integrally with the nozzle movement unit 53 when the nozzle movement unit 53 moves the slit nozzle 2 in the horizontal direction (Y direction), and each time the grid scale provided on the scale unit 55a is read. That is, a pulse signal is output every time the slit nozzle 2 advances a certain distance. The control unit 8 detects the amount of displacement of the detection unit 55b from a predetermined reference position by counting the number of pulses output from the detection unit 55b, thereby detecting the position of the slit nozzle 2. The slit nozzle 2 and the height sensor 6 move integrally via the nozzle support 51 in the horizontal direction. Therefore, the output signal of the position sensor 55 indicates the horizontal position of the slit nozzle 2 and at the same time, indicates the horizontal position of the height sensor 6.

FIG. 3 is a diagram showing the configuration of the height sensor. The height sensor 6 detects the light projecting unit 61 that emits the laser beam L downward toward the measurement object T, the driver 62 that drives the light projecting unit 61, and the reflected light from the measurement object T. It includes a light receiving unit 63 and a signal processing unit 64 that processes a signal output from the light receiving unit 63. In this embodiment, the object T to be measured is the surface Sa of the substrate S or the surface of the film F formed on the surface Sa. The height sensor 6 is the height of the measurement object T in the vertical direction based on the distance from the height sensor 6 to the measurement object T, that is, the arrangement position of the height sensor 6 according to the following principle. Has a function to measure.

The light L emitted from the light projecting unit 61 is reflected on the surface of the measurement object T, and the reflected light is received by the light receiving unit 63. The light receiving unit 63 is a one-dimensional image sensor, and as shown by the dotted arrow in the figure, the incident position of the reflected light on the light receiving unit 63 changes according to the distance between the height sensor 6 and the object T to be measured. Utilizing this fact, the signal processing unit 64 can detect the distance between the height sensor 6 and the measurement object T at the position directly below. The height sensor 6 is fixed to the beam member 51a. Therefore, it follows the movement of the slit nozzle 2 in the horizontal direction, but the vertical position is fixed and does not follow the ascending / descending of the slit nozzle 2. Therefore, the height sensor 6 can detect the vertical height of the surface Sa of the substrate S located directly below, or the vertical height of the surface of the film F formed on the substrate S. The height sensor 6 may be any as long as it can detect the distance to the facing surface, and is not limited to the one based on the above principle.

FIG. 4 is a block diagram showing an electrical configuration of a control unit of this image pickup apparatus. The control unit 8 has a CPU (Central Processing Unit) 81 that executes a predetermined control program to cause each unit to execute a predetermined operation, a memory 82 that stores data generated by the operation of the CPU 81 in a short period of time, and a CPU 81. It is provided with a storage 83 for storing a control program to be executed and various data, and an interface 84 for exchanging information with an external device and an operator.

The control unit 8 supplies negative pressure for sucking the substrate S to each part of the above-mentioned device, specifically, the nozzle elevating mechanism 22, the nozzle moving part 53, and the suction port provided on the stage 4, as needed. It controls the adsorption control unit 42, the coating liquid supply unit 25 that supplies the coating liquid to the slit nozzle 2, and the like.

Further, the CPU 81 executes a control program stored in the storage 83 to realize functional blocks such as the information acquisition unit 811 and the film thickness calculation unit 812 in software. The information acquisition unit 811 counts the pulse signal output from the position sensor 55, and creates position information indicating the relative position of the height sensor 6 with respect to the substrate S in the Y direction from the count value. Further, as will be described in detail later, the information acquisition unit 811 and the height information of the surface of the substrate S or the film F detected by the height sensor 6 based on the signals output from the height sensor 6 and the position sensor 55. , Acquire the correspondence information associated with the position information based on the output of the position sensor 55 when the height is detected. The film thickness calculation unit 812 calculates the thickness of the film F formed on the surface Sa of the substrate S for each position in the Y direction based on the acquired correspondence information. As a result, a film thickness profile representing the thickness distribution for each position of the film F is obtained. Which position on the substrate S the obtained film thickness is can be grasped from the position information created from the output of the position sensor 55.

FIG. 5 is a diagram showing a coating operation by this coating device. FIG. 5A shows the initial position of the coating processing unit 5. The initial position of the coating processing unit 5 is a position closer to (+ Y) side than the substrate S on the stage 4 in the horizontal direction, and at this time, the slit nozzle 2 is retracted upward. When starting the coating operation, the nozzle moving unit 53 moves the slit nozzle 2 from the initial position to the coating starting position.

FIG. 5B shows the coating start position. The coating start position is a position in which the slit nozzle 2 is slightly closer to the inside of the substrate S than the (+ Y) side end portion of the substrate S in the horizontal direction. After the nozzle moving portion 53 moves horizontally from the initial position of the slit nozzle 2, the slit nozzle 2 is lowered as shown in FIG. 5 (b), and the discharge port 21 creates a predetermined gap with respect to the surface Sa of the substrate S. Position them at opposite positions. The position of the slit nozzle 2 at this time is the coating start position.

From this state, the discharge of the coating liquid from the discharge port 21 is started, and as shown in FIG. 5C, the scanning movement of the slit nozzle 2 in the (−Y) direction is started. The slit nozzle S scans and moves along the surface Sa of the substrate S at a constant speed while maintaining a constant gap with respect to the surface Sa of the substrate S, so that a film F due to the coating liquid is formed on the surface Sa of the substrate S. To.

As shown in FIG. 5D, when the slit nozzle 2 reaches the coating end position near the (−Y) side end portion of the substrate S, the discharge of the coating liquid from the discharge port 21 is stopped, and the dotted line in the figure shows. As shown, the slit nozzle 2 retracts upward. This is the coating operation. Then, as shown in FIG. 5 (e), the slit nozzle 2 moves in the (+ Y) direction and finally returns to the initial position shown in FIG. 5 (a). This operation will be referred to as "return operation" below.

Further, in the above operation, the slit nozzle 2 reciprocates from the initial position to the coating end position, and the path during the coating operation in which the slit nozzle 2 moves from the initial position to the coating end position is referred to as “outward route”. The return motion path that moves from the coating end position to the initial position is called the "return path".

In the continuous film forming process in which the film F is sequentially formed on the plurality of substrates S, the above-mentioned processing is repeatedly executed for each substrate S. In the return operation described above, in order to start the application operation to the next substrate S, the slit nozzle 2 is initially set in a state where the coating liquid is not discharged from the discharge port 21 and in a state where the slit nozzle 2 is retracted upward. This is an operation to return to the position. Since this operation does not contribute to film formation, the moving speed of the slit nozzle 2 at this time can be made faster than the moving speed in the coating operation.

In the above-mentioned series of operations, in this embodiment, the thickness of the film F formed on the surface Sa of all the substrates S to be processed is measured. If the measured film thickness is out of the specified range, the operation is stopped. By doing so, it is possible to maintain a constant film formation quality for the treated substrate S, and by optimizing the film formation conditions at any time according to the detection result, stable film formation with good quality can be achieved. It will be possible to execute. The processing contents will be described below.

FIG. 6 is a flowchart showing the operation of this coating device. This operation is executed by the CPU 81 of the control unit 8 executing a control program stored in the storage 83 and causing each unit of the device to perform a predetermined operation. Since the outline of the coating operation of applying the coating liquid to the substrate S using the slit nozzle 2 and the return operation of the slit nozzle 2 after the application is completed has been described above, the film thickness is mainly measured here. The operation related to is explained.

Prior to the coating operation, height measurement by the height sensor 6 and position measurement by the position sensor 55 are started (step S101). After that, the execution of the above-mentioned coating operation is started (step S102). At the start of the coating operation, the height sensor 6 irradiates the upper surface 41 of the stage 4 with the light beam L, and detects the height of the upper surface 41 with respect to the position of the height sensor 6. When the nozzle moving portion 53 moves the nozzle support 51 to move the slit nozzle 2 horizontally, the height detected when the (+ Y) side end portion of the substrate S reaches the position directly below the height sensor 6 is It changes abruptly, so that the position of the end portion of the substrate S is detected. By constantly monitoring the output of the height sensor 6 by the information acquisition unit 811, it is possible to detect the end portion of the substrate S that moves relative to the slit nozzle 2.

When the end portion of the substrate S is detected (step S103), the position of the height sensor 6 detected based on the output pulse from the position sensor 55 reaches a predetermined measurement position with the end portion as a reference. Every time (step S104), the output signal of the height sensor 6 is acquired (step S105). For example, the height measurement can be performed every 1 mm from the end of the substrate S. The information acquisition unit 811 mounted on the CPU 81 is a position sensor 55 that indicates the height information of the upper surface Sa of the substrate S measured by the height sensor 6 and the horizontal position of the height sensor 6 when it is detected. The position information is acquired at each position for each position, and the "first information" in which these are associated with each other on a one-to-one basis is stored and stored in the memory 82 (step S106).

When the slit nozzle 2 reaches the (−Y) side end of the substrate S and the coating operation is completed (step S107), the return operation for returning the slit nozzle 2 to the initial position is executed (step S108). As shown in FIG. 5D, at the end of the coating operation, the height sensor 6 reaches the (−Y) side of the (−Y) side end of the substrate S. Therefore, it is possible to detect the position of the (−Y) side end portion of the substrate S from the output of the height sensor 6.

Even in the return operation, the height measurement by the height sensor 6 is continuously performed. That is, every time the horizontal position of the height sensor 6 obtained from the output of the position sensor 55 reaches a predetermined measurement position after the (−Y) side end portion of the substrate S is detected (step S109) (step S110). ), The output signal of the height sensor 6 is acquired (step S111), and the position information and the height information of the position sensor 55 at that time are associated with each other as "second information" and stored and stored in the memory 82 (step). S112). At this time, what is measured by the height sensor 6 is the height of the surface of the film F formed on the surface Sa of the substrate S.

The height measurement is continuously executed until the return operation is completed and the slit nozzle 2 returns to the initial position (step S113). At the end of the return operation, the slit nozzle 2 has returned to the initial position shown in FIG. 5A, and at this time, the height sensor 6 has moved to the (+ Y) side of the (+ Y) side end of the substrate S. There is. Therefore, even in the return operation, it is possible to grasp the position of the (+ Y) side end portion of the substrate S of the substrate S from the output signal of the height sensor 6.

In this way, the first information in which the height information and the position information of the surface Sa of the substrate S before coating are associated with each other on the outward route, and the height information and the position information on the surface of the film F after coating are associated with each other on the return route. 2 When the information is acquired, the film thickness calculation unit 812 aligns between them (step S114) and obtains a film thickness profile indicating the thickness at each position of the film F (step S115). .. This completes the processing for one substrate S. When processing is continuously performed on the new substrate S, the above operation is repeated after the substrate S is replaced.

FIG. 7 is a diagram showing the principle of film thickness calculation. FIG. 7A shows an example of "first information" in which the height information and the position information obtained in the coating operation are associated with each other. Further, FIG. 7B shows an example of "second information" in which the height information and the position information obtained in the return operation are associated with each other. Here, the size of the substrate S in the Y direction is 1000 mm, and the (+ Y) side end thereof is referred to as the "tip" or "tip" of the substrate S because it is the front end side of the substrate S in relative movement with respect to the slit nozzle 2. Refer to. Similarly, the end on the opposite side, that is, the (−Y) side, may be referred to as a “rear end”.

As shown in FIG. 7A, in the first information created during the coating operation, the height measurement value A of the surface Sa of the substrate S is acquired every 1 mm in the Y direction in order from the tip of the substrate. .. On the other hand, in the return operation, as shown in FIG. 7B, the height measurement value B on the surface of the film F is acquired in order from the position farthest from the tip of the substrate. The measured values A and B may vary due to variations in the thickness of the substrate S and the film F.

From these measurement results, as shown in FIG. 7C, by taking the difference between the substrate height measurement value A and the film height measurement value B at the positions where the distance from the substrate tip is the same, the position is taken. The film thickness in can be obtained. By performing the same calculation at each position, a film thickness profile representing the film thickness at each position can be obtained.

As described above, in this embodiment, in the reciprocating operation of the slit nozzle 2 with respect to the substrate S, the height of the substrate surface Sa before coating is measured on the outward path, and the height of the film F surface after coating is measured on the return path. To. Since the height measurement value is stored in the memory 82 in association with the position of the height sensor 6 at that time, the height measurement values of the positions corresponding to each other between the outward route and the return route are subtracted. Therefore, even if the thickness of the substrate S or the film F varies, it is possible to correctly obtain the film thickness at each position.

The reciprocating operation of the slit nozzle 2 in the processing for one substrate S is an indispensable step for continuously coating a plurality of substrates S regardless of the necessity of film thickness measurement. The film thickness measurement in the present embodiment does not affect the tact time of such a continuous film forming process and does not cause a decrease in productivity. Therefore, the film thickness measurement method of the present embodiment is suitable as an in-line film thickness measurement method in the continuous film formation process.

As described above, the moving speed of the slit nozzle 2 may differ between the outward route and the returning route, but it is related to the moving speed by acquiring the height measurement value in association with the measurement position information. It is possible to properly align the measurement position between the outward route and the return route. Therefore, the film thickness can be accurately measured even when the nozzle movement speed changes during the scanning movement on either the outward route or the return route. Such an effect cannot be obtained simply by recording the measurement data in chronological order.

By the way, in the description of the above embodiment, the position information obtained based on the output of the position sensor 55 and associated with the height information by the height sensor 6 is at the time when the height sensor 6 measures the height. It is assumed that the height sensor 6 represents the horizontal position with respect to the substrate S. However, in an actual device, the recorded position information may not represent the correct position of the height sensor 6. This is because there is a time delay between the position detection based on the output of the position sensor 55 and the height detection by the height sensor 6 before the change in the physical phenomenon is detected as a signal, and the height sensor 6 This is because there is a time lag between the time when it is determined that the height sensor has reached the measurement position and the time when the information is transmitted to each part and the output signal of the height sensor 6 is actually taken in.

When the height measurement of the substrate S and the height measurement of the film F are executed when the slit nozzle 2 is moved in the same direction and at the same speed, the same amount of time delay occurs in both measurements, so that the difference is obtained. There is no particular problem in seeking. However, when at least one of the moving direction and the moving speed of the slit nozzle 2 is different, an error due to this time delay (response time) may not be negligible. Next, the response to this problem will be described.

FIG. 8 is a diagram illustrating the principle of correspondence to the response time. FIG. 8A is a timing chart showing the response time on the outward route. It is assumed that the output signal of the height sensor 6 is constantly output at a constant sampling cycle. Further, the kth measurement position (k = 1, 2, ...) The height sensor 6 should perform the measurement is represented by the reference numeral Y (k). For example, assuming that the interval between the measurement positions corresponds to the output pulse number 10 of the position sensor 55 which is a linear encoder, as shown in the figure, once every 10 pulses are output from the position sensor 55. , The output of the height sensor 6 is captured. At this time, a time delay ΔT occurs until the pulse count value reaches a predetermined value and the output of the height sensor 6 is read accordingly.

In the figure, the circles indicate the acquisition timing of the sample in which the signal of the height sensor 6 is taken as valid. In this way, it is detected from the output of the position sensor 55 that the measurement position has been reached, and there is a time difference ΔT until the height measurement value is acquired accordingly, and the height sensor 6 is also moving during this time. .. Therefore, the position of the height sensor 6 when the height measurement value is determined is not the original position Y (k), but the displacement amount ΔYa represented by the product of the time difference ΔT and the moving speed is after the substrate S. The position is shifted to the end side.

Considering the return route, as shown in FIG. 8B, the sampling cycle of the height sensor 6 is the same as the above, but the pulse output cycle of the position sensor 55 becomes shorter because the moving speed of the slit nozzle 2 is high. Further, the moving direction of the slit nozzle 2 (and the optical sensor 6) is from the rear end side to the front end side of the substrate S opposite to the above.

Similar to the outward route, the height is measured when the count value of the output pulse of the position sensor 55 reaches a predetermined value. Since it is considered that the time delay amount ΔT due to the response time of the device does not change, the height measurement value corresponding to the measurement position Y (k) is obtained at a position shifted from the measurement position Y (k) by ΔYb toward the tip of the substrate. It will be the one that was done. This deviation amount ΔYb is a value obtained by multiplying the time difference ΔT by the moving speed of the slit nozzle 2, and if the moving speed is different from the outward route, the deviation amount is also different.

As described above, the actual height acquisition position corresponding to the measurement position Y (k) is deviated by ΔYa on the outward path and ΔYb on the return path, and the deviating directions are opposite. Therefore, the amount of misalignment between the outward route and the return route is (ΔYa + ΔYb). Therefore, the comparison of the height measurement values A and B corresponding to the same measurement position Y (a) may include an error.

One method of solving this problem is to shift the time or the measurement position in consideration of the above at the time of acquiring the height measurement value. That is, the deviation amounts ΔT, ΔYa, ΔYb and the like can be experimentally obtained in advance. Therefore, by shifting the setting of the measurement position or the acquisition timing of the height measurement value by the amount that allows for this deviation on at least one of the outward route and the return route, the effective measurement position between the outward route and the return route is matched. It is possible to make it.

FIG. 8C shows another method for solving the above problem. In this example, the height measurement itself is the same as that of the above embodiment, and no shift is performed. Instead of this, a method of interpolating the height measurement value that would have been acquired at the measurement position Y (k) from the measurement values before and after that is adopted. As shown in the figure, the height measurement value A (k) of the substrate surface Sa acquired corresponding to the measurement position Y (k) is actually located at the rear end side by ΔYa from the original position Y (k). It was acquired at a misaligned position.

Regarding the height of the substrate S at the original position Y (k), the values A (k-1) and A (k) obtained at the positions Y (k-1) and Y (k) before and after this position are sandwiched, respectively. ) Can be estimated. For example, the height of the substrate at the measurement position Y (k) can be estimated by linear interpolation between both measurement values. Similarly, for the height measurement value B obtained by measuring the height of the film F, the values B (k) acquired at the positions Y (k) and Y (k + 1) before and after the original measurement position Y (k), respectively. And B (k + 1) can be estimated by interpolation. Although linear interpolation has been described here as the simplest example, the interpolation method is not limited to this, and other known methods such as curve approximation may be used.

By calculating the difference between the estimated height measurement values A and B at the measurement position Y (k) thus obtained, the film thickness T (k) at the position can be obtained. As described above, the deviation of the measurement position due to the response time of the apparatus occurs in the opposite direction between the outward route and the return route, so that the relative deviation becomes large and may cause a measurement error. In particular, when the moving speed of the slit nozzle 2 is increased, the amount of displacement also increases. Therefore, it is desirable to take measures to eliminate the deviation by the above-mentioned method.

In the above embodiment, using a single height sensor 6, the height of the substrate surface Sa is measured on the outward path in the reciprocating operation of the slit nozzle 2, and the height of the film F is measured on the return path, and the measurement is performed at the same position. The film thickness is obtained by calculating the difference between the results. On the other hand, as will be described next, it is also possible to provide height sensors in front of and behind the nozzles to detect the height of the substrate and the height of the film individually.

FIG. 9 is a side view showing a main part of the second embodiment of the substrate processing apparatus according to the present invention. As shown in FIG. 9, in this embodiment, the height sensor 6a is provided on the (−Y) side side surface of the beam member 51a of the nozzle support 51, and the height sensor 6b is provided on the (+ Y) side side surface. .. The configuration and operation of these height sensors 6a and 6b are the same as those of the height sensor 6 of the first embodiment. Further, since the other configurations can be the same as those of the first embodiment, the same reference numerals are given to the same configurations as those of the first embodiment, and the illustration and detailed description thereof will be omitted.

In this embodiment, the height sensor 6a facing the surface Sa of the substrate S to which the coating liquid is not applied sets the height of the substrate S and the height facing the surface of the film F formed on the substrate S after coating. The sensor 6b measures the height of the film F, respectively. Then, the film thickness is obtained from the difference between the measured value of the substrate height and the measured value of the film height at the same measurement position.

Also in this embodiment, the height measurement values measured by the height sensors 6a and 6b are acquired in association with the position information of the height sensors 6a and 6b at the time of measurement with respect to the substrate S. , It is possible to correctly obtain the film thickness at the position by calculating the height measurement values acquired at the same position. Further, it is possible to grasp which position of the substrate S the obtained film thickness corresponds to by associating the obtained film thickness with the position information. Further, in this case, since the film thickness can be measured by scanning the slit nozzle 2 with respect to the substrate S in one direction, for example, a plurality of substrates are sequentially conveyed in one direction to a position facing the nozzle to perform coating. It can also be applied to a film forming process that does not assume the reciprocating movement of the nozzle, such as an apparatus or an apparatus that continuously applies a long sheet.

As described above, in the above-described embodiment, the coating device 1 functions as the "board processing device" of the present invention, and the slit nozzle 2, the nozzle support 51, and the nozzle moving portion 53 are the "base processing devices" of the present invention, respectively. It functions as a "nozzle", "support part" and "moving part". Further, the position sensor 55 functions as the "position detection unit" of the present invention. Further, in the first and second embodiments, the height sensors 6, 6a and 6b function as the "distance measuring unit" of the present invention.

Further, in the above embodiment, the height measurement value A corresponds to the "first distance" of the present invention, while the height measurement value B corresponds to the "second distance" of the present invention. Further, the information in which the height measurement value A and the position information are associated (FIG. 7A) corresponds to the "first information" of the present invention, and the information in which the height measurement value B and the position information are associated with each other. (FIG. 7 (b)) corresponds to the "second information" of the present invention.

The present invention is not limited to the above-described embodiment, and various modifications can be made other than those described above as long as the present invention is not deviated from the gist thereof. For example, in the coating device 1 of the above embodiment, the relative movement of the slit nozzle 2 is realized by moving the slit nozzle 2 with respect to the substrate S fixed to the stage 4, but the substrate moves with respect to the fixed nozzle. It is possible to apply the present invention to a device in which relative movement is realized.

Further, in the above embodiment, the height sensor 6 is arranged so as to face the central portion of the substrate S in the X direction, and the film thickness is measured at this position. However, the arrangement position of the height sensor in the X direction is It is not limited to this, and may be arbitrary, and a plurality of height sensors may be arranged in the X direction. In this case, by executing the above-mentioned processing for each height sensor, it is possible to measure the film thickness at each position in the film.

Further, as an optical sensor that can be used as the "distance measuring unit" of the present invention, the reflected light from the surface of the film F and the reflected light transmitted through the film F and reflected by the substrate surface Sa are individually detected. What can be done is commercialized. When the film F has sufficient light transmittance, by using such an optical sensor, it is possible to perform alignment between the measured height of the substrate upper surface Sa and the measured height of the film F as described above. It is possible to measure the film thickness immediately. However, since the film F formed on the substrate S is not limited to a transparent one, it is preferable that the above processing can be executed even in an apparatus equipped with such an optical sensor. By doing so, it is possible to accurately measure the film thickness not only for the transparent film but also for the opaque film. Further, in order to clarify which position of the substrate S the measured film thickness is, it is effective to associate the position information based on the output of the position sensor 55 with the film thickness measurement result. ..

Further, in the above embodiment, both the slit nozzle 2 and the height sensor 6 are attached to the nozzle support 51, and when the slit nozzle 2 moves in the Y direction, the height sensor 6 also moves integrally. However, the slit nozzle and the height sensor may be configured to be moved by individual moving mechanisms. When the configuration is configured to move integrally in the Y direction as in the above embodiment, it is advantageous in terms of the size and cost of the device because it does not require an individual moving mechanism, and the slit nozzle and the height sensor are separate. It is possible to avoid the problem of interference that may occur when moving to.

Further, in the above embodiment, the height sensor 6 is attached to the nozzle support 51 and does not follow the ascending / descending of the slit nozzle 53. Instead of this, for example, the height sensor may be configured to move up and down integrally with the slit nozzle. In order to realize this in the first embodiment, a separate process for correcting the difference in the vertical position of the height sensor between the outward path and the return path is required. On the other hand, in the configuration shown as the second embodiment, since the two height sensors 6a and 6b move up and down integrally with the slit nozzle 2 and the positional relationship between the two height sensors does not change, the position in the vertical direction is appropriate in advance. As long as it is calibrated, there is no particular need for correction.

As described above, as described by exemplifying a specific embodiment, in the substrate processing apparatus according to the present invention, the nozzle moves relative to the substrate in parallel with the moving direction, and the ranging unit moves in conjunction with the nozzle on the substrate. It may be configured to move relative to the relative. In this case, a support portion that supports the nozzle and the ranging unit and moves relative to the substrate in the moving direction may be further provided. According to such a configuration, it is sufficient for the moving unit to be able to move the distance measuring unit and the nozzle integrally, and it is possible to avoid complicated configuration of the moving unit. Further, there is no problem of interference when the distance measuring unit and the nozzle move individually.

Further, the distance measuring unit moves relative to the main surface before application of the coating liquid to measure the first distance at a plurality of different positions, and further moves relative to the main surface after application to measure the first distance at a plurality of different positions. It may be configured to measure the second distance. According to such a configuration, the film thickness can be measured at a plurality of positions along the moving direction of the ranging unit, and the film thickness profile in the direction can be obtained.

In this case, for example, the nozzle moves relative to the substrate in one direction from a predetermined movement start position, applies the coating liquid to the main surface, and then moves relative to the movement start position in the opposite direction to the substrate to measure the distance. The unit is arranged in front of the nozzle in one direction and moves integrally with the nozzle with respect to the substrate, measures the first distance when moving in one direction, and measures the second distance when moving in the opposite direction. It may be configured to measure.

According to such a configuration, the first distance and the second distance can be measured by a single distance measuring unit, so that the device configuration can be simplified. When such reciprocating movement of the nozzle is incorporated as an indispensable part of a series of film forming processes, the distance measuring unit performs measurement in conjunction with this reciprocating movement, thereby reducing the productivity of the film forming process. It is possible to measure the film thickness without any problem.

Alternatively, for example, the nozzle moves relative to the substrate in one direction to apply the coating liquid to the main surface, a pair of distance measuring portions are arranged across the nozzle in one direction, and the front of the nozzle in one direction. The ranging unit arranged in may measure the first distance, and the ranging unit arranged behind the nozzle may measure the second distance. According to such a configuration, since the first distance and the second distance are measured before and after the nozzle, reciprocating motion for film thickness measurement is unnecessary. In a device in which the relative movement of the nozzle with respect to the substrate is limited to one direction, the film thickness measurement by this configuration is effective.

Further, for example, the film thickness calculation unit may be configured to correct the positional deviation due to the response time between the position detection by the position detection unit and the distance measurement by the distance measuring unit. According to such a configuration, it is possible to accurately obtain the film thickness in response to the problem that the measurement positions of the first distance and the second distance deviate from each other due to the response time of the apparatus.

Further, for example, the ranging unit may have a configuration including a light projecting unit that irradiates light toward the surface to be measured and a light receiving unit that detects the reflected light from the surface to be measured. As a sensor product that optically detects the distance to the surface to be measured, those corresponding to various measurement distances and resolutions are available. By selecting one of these having appropriate characteristics according to the purpose of measurement, it becomes possible to easily realize film thickness measurement with the required accuracy.

The present invention is effective when the coating liquid is applied to a substrate and the film thickness formed is measured, and particularly functions as an in-line type film thickness measurement incorporated in a film forming process.

1 Coating equipment (board processing equipment)
2 Slit nozzle (nozzle)
6,6a, 6b Height sensor (distance measuring unit)
51 Nozzle support (support part)
53 Nozzle moving part (moving part)
55 Position sensor (position detection unit)
81 CPU (information acquisition unit, film thickness calculation unit)
811 Information acquisition unit 812 Film thickness calculation unit S Substrate Sa Substrate W top surface (main surface)

Claims (7)

In a substrate processing device that forms a film of coating liquid on the main surface of a substrate,
A nozzle that moves relative to the substrate while discharging the coating liquid from a slit-shaped discharge port to apply the coating liquid to the main surface to form the film.
A ranging unit that is arranged facing the main surface and measures a first distance to the main surface and a second distance to the surface of the film coated on the main surface.
A moving portion that moves the ranging unit integrally with the nozzle and relative to the substrate in a moving direction along the main surface.
A position detection unit that detects the position of the distance measuring unit with respect to the substrate in the moving direction, and a position detecting unit.
The first information in which the position of the distance measuring unit detected by the position detection unit and the first distance measured by the distance measuring unit at the position are associated with each other, and the distance measuring unit detected by the position detection unit. The information acquisition unit that acquires the second information in which the position of the above is associated with the second distance measured by the distance measuring unit at the position.
Based on the first information and the second information, the thickness of the film corresponding to the position from the difference between the first distance and the second distance when the positions of the distance measuring portions with respect to the substrate are the same as each other. It is equipped with a film thickness calculation unit that calculates the distance .
The nozzle moves relative to the substrate in one direction from a predetermined movement start position, and after applying the coating liquid to the main surface, the nozzle is directed to the substrate in a direction opposite to the one direction and said. Relative movement to the movement start position at a relative speed faster than relative movement in one direction,
The distance measuring unit is arranged in front of the nozzle in the one direction, and is different from each other along the relative movement direction when relatively moving in the one direction with respect to the main surface before application of the coating liquid. The first distance is measured at a plurality of positions, and the second distance is measured at a plurality of different positions along the relative movement direction when the main surface after coating is relatively moved in the opposite direction.
The film thickness calculation unit detects the position by the position detection unit and measures the distance by the distance measurement unit according to the relative movement speed in the relative movement of the distance measurement unit in the one direction and the opposite direction with respect to the substrate. A board processing device that corrects the positional deviation caused by the response time between and . The substrate processing apparatus according to claim 1 , further comprising a support portion that supports the nozzle and the ranging unit and moves relative to the substrate in the moving direction. The substrate processing apparatus according to claim 1 or 2 , wherein the distance measuring unit includes a light projecting unit that irradiates light toward the surface to be measured and a light receiving unit that detects light reflected from the surface to be measured. Claims 1 to 3 correct the misalignment based on the time difference from the position detection to the distance measurement and the moving speed of the distance measuring unit in the movement in one direction and the movement in the opposite direction. The substrate processing apparatus according to any one of. The thickness of the film is determined based on the measurement results obtained by the distance measuring unit with different measurement timings between the movement of the distance measuring unit in one direction and the movement in the opposite direction. The substrate processing apparatus according to claim 4. The distance measuring unit intermittently acquires the result of the distance measurement.
The film thickness calculation unit specifies measurement positions corresponding to each other between the movement in one direction and the movement in the opposite direction by the distance measuring unit, and determines the thickness of the film at the measurement position. The result of the distance measurement acquired at the position sandwiching the measurement position is obtained based on the interpolated value.
The substrate processing apparatus according to claim 4. In a substrate processing method in which a nozzle for discharging a coating liquid from a slit-shaped discharge port is relatively moved with respect to a substrate and the coating liquid is applied to the main surface of the substrate to form a film of the coating liquid.
The distance measuring unit arranged facing the main surface is moved relative to the substrate in a moving direction along the main surface integrally with the nozzle, and the position of the distance measuring unit with respect to the substrate in the moving direction is determined. In addition to being detected by the position detection unit, the distance measuring unit measures the first distance to the main surface and the second distance to the surface of the film coated on the main surface.
The first information in which the position of the distance measuring unit detected by the position detection unit and the first distance measured by the distance measuring unit at the position are associated with each other, and the distance measuring unit detected by the position detection unit. The second information in which the position of the above is associated with the second distance measured by the distance measuring unit at the position is acquired.
Based on the first information and the second information, the film thickness detection unit moves to the position from the difference between the first distance and the second distance when the positions of the distance measuring units with respect to the substrate are the same as each other. Calculate the thickness of the corresponding film and
The nozzle moves relative to the substrate in one direction from a predetermined movement start position, and after applying the coating liquid to the main surface, the nozzle is directed to the substrate in a direction opposite to the one direction and said. Relative movement to the movement start position at a relative speed faster than relative movement in one direction,
The distance measuring unit is arranged in front of the nozzle in the one direction, and is different from each other along the relative movement direction when relatively moving in the one direction with respect to the main surface before application of the coating liquid. The first distance is measured at a plurality of positions, and the second distance is measured at a plurality of different positions along the relative movement direction when the main surface after coating is relatively moved in the opposite direction.
The film thickness calculation unit detects the position by the position detection unit and measures the distance by the distance measurement unit according to the relative movement speed in the relative movement of the distance measurement unit in the one direction and the opposite direction with respect to the substrate. A board processing method that corrects the positional deviation caused by the response time between and .

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