JP4041301B2 - Liquid film formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a liquid film enhancing reliability for uniformly coating a liquid on a base plate to be treated by a simultaneous control of three parameters. SOLUTION: In the method for forming a liquid film, a helical coating is employed in which a movement pitch of a liquid feed part is varied and the liquid applied on the base plate to be treated is not moved by a centrifugal force, a higher-order function for controlling a movement position of the liquid feed part, a feeding speed of the liquid delivered from the liquid feed part and a revolution number of the base plate to be treated corresponding to a treating time respectively is previously set. A control is carried out while the movement position of the liquid feed part, the feeding speed of the liquid delivered from the liquid feed part and the revolution number of the base plate to be treated at the treating time t are subsequently determined based on the higher-order function.

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a liquid film forming method for forming a film by applying a liquid to a substrate to be processed so as to draw a spiral trajectory, and in particular, the position of a liquid supply nozzle that discharges liquid and the liquid discharged from the nozzle. The present invention relates to a liquid film forming method which is performed by simultaneously controlling three parameters of the liquid supply speed of the liquid and the rotation speed of the substrate to be processed.
[0002]
[Prior art]
  In a lithography process in semiconductor device manufacturing, a spin coating method has been employed as a liquid film forming method for applying a chemical solution to the surface of a substrate to be processed. However, this method is wasteful because a large amount of chemical solution is scattered from the wafer surface, and the chemical solution thus discharged has an environmental impact. Further, in the case of a square substrate or a large circular substrate of 12 inches or more, there is a problem that turbulence is generated at the outer peripheral portion of the substrate and the film thickness becomes non-uniform.
  Therefore, conventionally, as a method for reducing the amount of the chemical solution to be used as much as possible, in Japanese Patent Laid-Open No. 2000-288450 and Japanese Patent Laid-Open No. 2000-350955, the chemical solution supply nozzle is set in the radial direction with respect to the rotating substrate. A liquid film forming method is employed in which a chemical solution is ejected while moving to a substrate and applied to the substrate to be processed so as to draw a spiral trajectory.
[0003]
  In the publication, when the liquid film is formed, when moving on the substrate to be processed, the resist liquid is discharged from the chemical liquid supply nozzle, the chemical liquid supply speed at the time of the discharge, the movement of the chemical liquid supply nozzle, the movement It describes that the speed, the rotation of the substrate, and the rotation speed thereof are appropriately controlled.
  That is, in the method of Japanese Patent Laid-Open No. 2000-288450, for example, regarding the discharge of the chemical solution from the chemical solution supply nozzle, when the chemical solution supply nozzle is moved on the substrate, the discharge of the chemical solution is continued or on the substrate of the chemical solution supply nozzle Depending on the position, the discharge of the chemical solution is interrupted to make the film thickness uniform and reduce the amount of resist used. In the method disclosed in Japanese Patent Laid-Open No. 2000-350955, the amount of the chemical solution supplied is gradually increased while the chemical solution supply nozzle is moved so that the amount of the chemical solution applied per unit area is equal between the central portion and the peripheral portion of the substrate. Thus, a uniform film is formed.
[0004]
[Problems to be solved by the invention]
  However, in such a conventional film forming method, all three parameters of the moving speed of the chemical liquid supply nozzle, the chemical liquid supply speed, and the substrate rotation speed necessary for forming a uniform liquid film by so-called spiral coating are variable with respect to time. Since it was not handled, it was unreliable in terms of obtaining a uniform liquid film even if the problem caused by the scattering of the chemical solution was solved.
[0005]
  Accordingly, an object of the present invention is to provide a liquid film forming method with improved reliability for uniformly applying a liquid on a substrate to be processed by simultaneous control of three parameters in order to solve such a conventional problem. Do.
[0006]
[Means for Solving the Problems]
[0007]
[0008]
[0009]
[0010]
[0011]
  ContractClaim1The liquid film forming method according to the method includes the step of setting, as the first position, one end of a moving section of a liquid supply unit that discharges liquid while moving in a radial direction with respect to a rotating substrate to be processed; And determining the number of rotations of the substrate to be processed when positioned at the outermost diameter of the liquid supply region of the substrate to be processed and the liquid supply amount qout per unit length of the assumed trajectory of the liquid dropped onto the substrate. And a step of setting the movement pitch so that the movement pitch in the radial direction of the liquid supply unit that occurs each time the substrate to be processed makes one round when the liquid supply unit exists at an arbitrary position; From the first position, the movement pitch of the liquid supply section at the first position, and the liquid supply amount qout, the liquid supply speed from the liquid supply section at the first position and the substrate rotation speed are determined. A step of supplying a liquid to the liquid supply unit; A second position where the liquid supply unit is positioned after a unit time from a rotation angle when the substrate to be processed is rotated for a unit time after being positioned at a position and a movement pitch of the liquid supply unit at the first position. Determining the position, and resetting the second position as a new first position until the second position reaches the other end of the moving section, and the liquid from the liquid supply unit at the first position. Determination of supply speed and substrate rotation speed,The relationship between the liquid supply speed and the radial position of the liquid supply unit with respect to time, and the relationship between the rotational speed of the substrate to be processed and the radial position of the liquid supply unit with respect to time as functionsThe process of determining and determinedTaekiBased on the number, it is checked whether the radial position of the liquid supply unit, the liquid supply speed and the calculated control value of the processing substrate rotation number match the current value, and the error correction of the control value is performed. Repeatedly, a liquid film is formed on the substrate to be processed.
[0012]
  And for such invention, the claim2And claims3Embodiments according to are preferred.
  For the substrate to be processedDiameterThe movement value of the liquid supply unit moving in the direction is from the center side to the peripheral side, or from the peripheral side to the center side, and the control value obtained for the liquid film formation process associated with the movement per unit time By repeatedly controlling the radial position of the liquid supply unit, the liquid supply speed, and the rotation speed of the substrate to be processed, a liquid film is formed on the substrate to be processed.
  Also,In order to apply feedback not only in the immediately preceding control value but also in the radial direction of the substrate to be processed, the control value before one rotation of the substrate to be processed is also used when correcting the control value calculated based on the function.thing.
[0013]
  Therefore, according to the present invention, the movement position of the liquid supply unit, the supply speed of the liquid discharged from the liquid supply unit, and the rotation speed of the substrate to be processed so that the liquid placed on the substrate to be processed does not move due to centrifugal force. Is obtained every unit time, and these three parameters are controlled at the same time, improving the reliability of coating control to make the liquid film uniform in spiral coating that applies a liquid by drawing a spiral trajectory on the substrate to be processed. Can be made. As a result, the liquid film on the substrate to be processed is applied more uniformly than the conventional one, which greatly contributes to improving the quality of the final product. In particular, the simultaneous control of these three parameters is preset.TaekiSince control is performed based on the number, control can be easily performed.
  Also, SekiIn the control based on the number, the liquid film can be uniformly distributed at a high level in the radial movement of the liquid supply unit with respect to the substrate to be processed from the central side to the peripheral side or vice versa. it can. Furthermore, since the control value is corrected based on the value before one rotation, the liquid application that draws a spiral locus can be appropriately controlled in units of one rotation.
[0014]
  Claim4The liquid film forming method according to the present invention draws a spiral trajectory of the liquid on the substrate to be processed by discharging the liquid from a liquid supply unit that moves in a radial direction on the substrate to be rotated. A method of forming a film, wherein a liquid discharged from the liquid supply unit and placed on the substrate to be processed is not moved by a centrifugal force at a radial position r from the center of the substrate to be processed. While maintaining the relationship in which the product of the liquid supply speed V and the rotation speed W of the substrate to be processed is constant, the rotation speed W of the substrate to be processed is decreased and the supply speed V of the liquid is increased. In this case, in order to control the moving position of the liquid supply unit, the supply speed of the liquid discharged from the liquid supply unit, and the rotation speed of the substrate to be processed according to the processing time t.No sekiSet the number in advance.No sekiThe control is performed while determining the moving position of the liquid supply unit at the processing time t, the supply speed of the liquid discharged from the liquid supply unit, and the rotation speed of the substrate to be processed based on the number of times. To do.
[0015]
  For the invention, the claim5To claims11Embodiments according to are preferred.
  That is, the process of forming a liquid film on the substrate to be processed by the liquid discharged from the liquid supply unit is divided into a plurality of regions.SecretaryNumbers are provided for each area.
  Before the boundary of the region approximates the theoretical valueSecretaryWhen trying to find a number,No sekiIt is provided in the part where the error in the number becomes large.
  The boundary of the region is provided when the rotation speed control of the substrate to be processed reaches a control limit value or when the liquid supply speed of the liquid discharged from the liquid supply unit reaches the control limit value. .
  The boundary of the region is an inflection point of any of the following values: movement position control of the liquid supply unit with respect to the processing time t, supply speed control of the liquid discharged from the liquid supply unit, and rotation speed control of the substrate to be processed Stipulated in
[0016]
  Processing time t at the boundary of the regionNo sekiSo that the number is continuousRelatedThe order and coefficient of the number are determined.
  The rotational speed control of the substrate to be processed is performed so that the sign of the rotational tangential acceleration is not reversed, and the liquid supply speed is controlled to reflect this control.
  The liquid supply unit is positioned at a distance r from the substrate center with respect to the substrate rotation speed Wout determined by the outermost diameter rout of the substrate to be processed and the liquid supply speed Vout from the liquid supply unit. The substrate rotation speed W is determined by the product of the square root of (rout / r) and the coefficient b and Wout, and the supply speed V is determined by the value obtained by dividing Vout by the square root of (rout / r) and the coefficient b. Be done.
[0017]
  Therefore, according to the present invention, the movement position of the liquid supply unit, the supply speed of the liquid discharged from the liquid supply unit, and the rotation speed of the substrate to be processed so that the liquid placed on the substrate to be processed does not move due to centrifugal force. Since the three parameters are simultaneously controlled and the three parameters are controlled simultaneously, the reliability of coating control for uniformizing the liquid film in the spiral coating in which a spiral trajectory is drawn on the substrate to be processed can be improved. . As a result, the liquid film on the substrate to be processed is applied more uniformly than the conventional one, which greatly contributes to improving the quality of the final product. In particular, the simultaneous control of these three parameters is preset.TaekiSince control is performed based on the number, control can be easily performed.
[0018]
  Moreover, the following effects are also produced according to the embodiment. That is, SekiBy setting the number divided into a plurality of regions, it is possible to perform appropriate control according to changing conditions such as centrifugal force. Appropriate for control by setting the boundary of the area in the part where the error from the theoretical value becomes largeNasekiYou can get a number. By providing the boundary of the region at the control limit value of the device, appropriate control according to the performance of each device constituting the liquid film forming apparatus can be performed. In the present invention in which the three parameters are controlled simultaneously, the three parameters can be controlled in the most preferable state by defining the boundary of the region by an inflection point of any value. Further, at such a boundary, the processing time tNo sekiSo that the number is continuousRelatedBy determining the order of the number and the coefficient, it is possible to prevent a sudden change in the coating state and form a uniform liquid film. In addition, since the rotation speed is controlled so that the rotation of the substrate to be processed does not change abruptly, movement due to the acceleration change of the liquid applied on the substrate to be processed can be prevented.
[0019]
  Claim12The liquid film forming method according to the method includes the step of setting, as the first position, one end of a moving section of a liquid supply unit that discharges liquid while moving in a radial direction with respect to a rotating substrate to be processed; And determining the number of rotations of the substrate to be processed when positioned at the outermost diameter of the liquid supply region of the substrate to be processed and the liquid supply amount qout per unit length of the assumed trajectory of the liquid dropped onto the substrate. From the process, the first position, the movement pitch of the liquid supply unit at the first position, and the liquid supply amount qout, the liquid supply speed from the liquid supply unit at the first position and the substrate rotation speed A rotation angle when the substrate to be processed is rotated for a unit time after the liquid supply unit is positioned at the first position, and a movement pitch of the liquid supply unit at the first position. The liquid supply unit is Determining the second position to be performed, and resetting the second position as a new first position until the second position reaches the other end of the moving section, and supplying the liquid at the first position. The liquid supply speed and the substrate rotation speedThe relationship between the liquid supply speed and the radial position of the liquid supply unit with respect to time, and the relationship between the rotational speed of the substrate to be processed and the radial position of the liquid supply unit with respect to time as functionsThe process of determining and determinedTaekiBased on the number, it is checked whether the radial position of the liquid supply unit, the liquid supply speed and the calculated control value of the processing substrate rotation number match the current value, and the error correction of the control value is performed. Repeatedly, a liquid film is formed on the substrate to be processed.
[0020]
  And for such invention, the claim13And claims14Embodiments according to are preferred.
  The moving direction of the liquid supply section that moves in the radial direction with respect to the substrate to be processed is from the central portion side to the peripheral portion side, or from the peripheral portion side to the central portion side. The liquid film is formed on the substrate to be processed by repeatedly controlling the radial position of the liquid supply unit, the liquid supply speed, and the substrate rotation speed according to the control value obtained every time.
  Also,In order to apply feedback not only in the immediately preceding control value but also in the radial direction of the substrate to be processed, the control value before one rotation of the substrate to be processed is also used when correcting the control value calculated based on the function.thing.
[0021]
  Therefore, according to the present invention, the movement position of the liquid supply unit, the supply speed of the liquid discharged from the liquid supply unit, and the rotation speed of the substrate to be processed so that the liquid placed on the substrate to be processed does not move due to centrifugal force. Is obtained every unit time, and these three parameters are controlled at the same time, so that the reliability of coating control for uniformizing the liquid film is improved in spiral coating in which a spiral trajectory is drawn on the substrate to be processed. be able to. As a result, the liquid film on the substrate to be processed is applied more uniformly than the conventional one, which greatly contributes to improving the quality of the final product. In particular, the simultaneous control of these three parameters is preset.TaekiSince control is performed based on the number, control can be easily performed.
  Also, SekiIn the control based on the number, the liquid film can be uniformly distributed at a high level in the radial movement of the liquid supply unit with respect to the substrate to be processed from the central side to the peripheral side or vice versa. it can. Furthermore, since the control value is corrected based on the value before one rotation, the liquid application that draws a spiral locus can be appropriately controlled in units of one rotation.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
  Next, an embodiment of a liquid film forming method according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a spiral coating apparatus for executing a liquid film forming method according to the present invention.
  In the spiral coating device 1, a drive system is configured in a box-shaped device main body 2. First, a rotary drive motor 3 is disposed on the bottom surface of the device main body 2, and a rotary table 4 is attached to a rotary shaft protruding upward. . The rotary table 4 is provided with a suction plate 5 on its upper surface, and is configured to horizontally vacuum-suck the substrate 10 to be processed placed thereon and rotate it by the rotational output of the rotary drive motor 3.
[0023]
  A processing container 6 is formed on the rotation drive motor 3 and encloses the rotary table 4 and the substrate 10 to be processed thereon. And the slit 6s for dropping a chemical | medical solution with respect to the to-be-processed substrate 10 from the top is formed in the lid | cover 6a of the processing container 6 in the radial direction. The slit 6s is cut out linearly from the center of the turntable 4, that is, from the center of the substrate to be processed to a position where the outermost diameter of the liquid film is reached. On the lid 6a having such a slit 6s, trays 7a and 7b for receiving a chemical discharged from the outside of the processing container 6 are provided at both ends of the slit 6s. This is because it is necessary to receive the chemical liquid discharged from the chemical liquid supply nozzle 8 other than when applying to the substrate 10 to be processed.
[0024]
  In the apparatus main body 2, a chemical solution supply nozzle 8 for applying a chemical solution to the substrate 10 to be processed is movably provided. The chemical solution supply nozzle 8 has a nozzle moving mechanism on the processing container 6 so as to move on the slit 6 s along the radial direction of the substrate 10 to be processed. Specifically, the slide rail 11 and the rotary shaft 13 connected to the nozzle moving motor 12 are arranged side by side, and slide between the slide rail 11 and linearly reciprocate between the chemical solution supply nozzle 8 and the rotary shaft 13. A ball screw or a magnetic screw that changes the rotational force of the nozzle moving motor 12 into a linear motion of the chemical solution supply nozzle 8 is configured.
[0025]
  The chemical solution supply nozzle 8 is connected to the chemical solution tank 15 containing the chemical solution by tubes 17 and 17 via a chemical solution supply pump 16. The chemical solution supply pump 16 operates the diaphragm 21 provided on the pump chamber 25 by the air pressure from the air pressure supply valve 18 to supply the chemical solution from the chemical solution tank 15 to the chemical solution supply nozzle 8 at a predetermined pressure. The pressure sensor 22 for detecting the discharge pressure of the chemical solution is built in, and the supply of the chemical solution is shut off in order to store the chemical solution in the pump chamber 25 and supply it at a predetermined pressure on the input side and the output side of the pump chamber 25. A valve 23 and a chemical liquid discharge cutoff valve 24 are provided.
[0026]
  Next, the spiral coating apparatus 1 is configured with a control system for controlling the drive system configured as described above. In this embodiment, the rotational speed of the substrate 10 to be processed, the driving speed of the chemical liquid supply nozzle 8 (position of the chemical liquid supply nozzle 8), and the chemical liquid supply speed (chemical liquid discharge pressure) from the chemical liquid supply nozzle 8 are used as parameters. Are simultaneously controlled. Therefore, a rotation controller 31 is connected to the rotation drive motor 3, a nozzle movement controller 32 is connected to the nozzle movement motor 12, and a pump controller 33 is connected to the air pressure supply valve 18 and the pressure sensor 22. Yes. While the chemical solution is supplied onto the substrate to be processed, the rotation speed of the substrate to be processed 10, the driving speed of the chemical solution supply nozzle 8 (position of the chemical solution supply nozzle 8), and the chemical solution supply speed from the chemical solution supply nozzle 8 (chemical solution) The discharge pressure is controlled by the controllers 31, 32, 33, and a main controller 30 is connected to these controllers so that they can be managed in an integrated manner.
[0027]
  Then, the liquid film formation method using the spiral coating device 1 is demonstrated below. In the liquid film forming method of this embodiment, instead of the spin coating method, so-called spiral coating is performed in which a fine jet of chemical liquid discharged from the chemical liquid supply nozzle 8 is spirally applied to the rotating substrate 10 to be processed. To do. Therefore, first, the rotation table 4 is rotated by the rotation drive motor 3, and the substrate 10 to be processed held by the suction plate 5 rotates at a predetermined number of rotations according to the output of the rotation drive motor 3. On the other hand, the chemical liquid in the chemical liquid tank 15 is pumped to the chemical liquid supply nozzle 8 by the chemical liquid supply pump 16, and the chemical liquid that has become a fine jet is discharged directly from the chemical liquid supply nozzle 8. The chemical liquid is discharged as a thin streamline without interruption, and is supplied onto the substrate to be processed 10 through the slit 6s while the chemical liquid supply nozzle 8 moves.
[0028]
  The chemical liquid is supplied to the substrate 10 to be processed when the chemical liquid supply nozzle 8 moves from the central portion toward the peripheral side or from the peripheral portion toward the central side. The chemical solution supply nozzle 8 is moved by driving the nozzle moving motor 12. When rotation is applied to the rotary shaft 13, the rotation is converted into a linear motion of the chemical solution supply nozzle 8 by a ball screw or magnetic screw (not shown). Therefore, the chemical solution supply nozzle 8 slides on the slide rail 11 and moves above the lit 6s without breaking the posture with the discharge port directly below.
[0029]
  Here, FIG. 2 is an image diagram of spiral coating, but when a liquid film is formed, if the chemical liquid is discharged from the chemical liquid supply nozzle 8 that moves in the radial direction with respect to the rotating substrate 10 to be processed, As shown in the figure, the fine jet chemicals are sequentially supplied in a spiral shape in a streamline. Then, the chemical solution supplied in a spiral shape spreads and the adjacent chemical solutions are combined with each other, and one liquid film is formed on the substrate 10 to be processed.
  The liquid film on the substrate 10 thus formed is then dried and removed of the solvent in the liquid film. The drying method includes heating, drying under reduced pressure below the saturated vapor pressure of the solvent, surface The method of making it contact with the air current is used.
[0030]
  By the way, the spiral application of the present embodiment, which is performed by driving the rotary drive motor 3 and the like as described above, stores the control program of each device, and according to this, under the control of the main controller 30, each controller 31, This is executed according to control commands from 32 and 33. That is, the rotation drive motor 3, the nozzle movement motor 12, and the chemical solution supply pump 16 are each configured such that the rotational speed of the substrate 10 to be processed, the moving speed of the chemical solution supply nozzle 8 (the position of the chemical solution supply nozzle 8), and A high-order function with respect to the processing time t using the chemical supply speed (chemical solution discharge pressure) from the chemical supply nozzle 8 as a parameter.(Hereinafter, it is assumed that the order of 1/2 is also included in the “high-order function”.)It is controlled by. FIG. 3 shows the nozzle position (a), discharge pressure (b), and substrate rotation speed (c) corresponding to the processing time t when each device is controlled based on such a high-order function. is there.
[0031]
  On the other hand, FIG. 5 is a diagram showing an application control flow for applying a chemical solution onto the substrate 10 to be processed while controlling three parameters based on a high-order function. The main controller 30 of the spiral coating device 1 stores a processing program for executing this coating control flow. Therefore, the coating process according to this flow will be described.
  First, when a chemical solution start signal is input to the substrate 10 to be processed, initialization processing is performed so that each drive system is in a predetermined state, such as the arrangement of the chemical solution supply nozzle 8 and the valve opening / closing of the chemical solution supply pump 16. (S1). As a specific operation of the initialization process, first, the chemical solution supply nozzle 8 is disposed on the central tray 7a. In the chemical liquid supply pump 16, the chemical liquid supply cutoff valve 23 is opened, the chemical liquid discharge cutoff valve 24 is closed, and the chemical liquid supply cutoff valve 23 is closed when the chemical liquid is drawn into the pump chamber 25 from the chemical liquid tank 15.
[0032]
  Then, after the initialization process is performed, a chemical solution discharge stabilization process is subsequently performed (S2). The chemical solution discharge stabilization process is a preparatory process for executing each parameter control by the higher-order function shown in FIG. 3, and FIG. 6 shows a sub-flow showing this chemical solution discharge stabilization process. FIG. 4 shows the nozzle position (a) in the radial direction of the substrate, the discharge pressure (b), and the rotation speed (c) of the substrate to be processed with reference to the center of the substrate corresponding to the processing time in the chemical liquid discharge stabilization processing. Each is shown.
[0033]
  First, in the chemical solution supply pump 16, both the shut-off valves 23 and 24 are closed, and the chemical solution in the pump chamber 25 is pressurized by a diaphragm 21 driven by the air pressure from the air pressure supply valve 18. This applied pressure is detected by the pressure sensor 22, and the discharge pressure of the chemical solution is adjusted to 0.3 MPa as shown in FIG. 4B by the control of the pump controller 33 based on the detected value of the air pressure supply valve 18. (S101). Further, rotation is given to the rotation drive motor 3 by the rotation controller 31, and the number of rotations of the substrate 10 to be processed is gradually increased (S102). Then, the passage of 2 seconds after the start of the process is confirmed (S103), and the chemical supply shutoff valve 23 of the chemical supply pump 16 is opened by the passage of time (S103: YES) (S104). Therefore, the chemical liquid is discharged from the chemical liquid supply nozzle 8 at 0.3 MPa. At this time, since the chemical liquid supply nozzle 8 is on the tray 7a, all the chemical liquid is received by the tray 7a.
[0034]
  Thereafter, the rotational speed of the substrate 10 to be processed continues to be further accelerated linearly as shown in FIG. 4C (S105). This state is continued until the processing time reaches 6 seconds. When the processing time reaches 6 seconds (S106: YES), the discharge pressure of the chemical solution is increased to 0.2 MPa over 2 seconds as shown in FIG. 4B. The pressure is reduced (S107). The decrease in the discharge pressure is controlled by the air pressure supply valve 18 based on the detection value from the pressure sensor 22, and the applied pressure of the diaphragm 21 that pumps the chemical liquid in the pump chamber 25 is suppressed by the air pressure. The reason why the discharge pressure is reduced to 0.2 MPa in this way is that the control limit value of the chemical liquid supply pump 16 that can discharge the chemical liquid as a fine jet from the chemical liquid supply nozzle 8 is 0.2 MPa.
[0035]
  After that, the rotational speed of the substrate 10 to be processed continues to be linearly accelerated as shown in FIG. 4C (S108), and the initial rotational speed (180 rpm) at which the application of the chemical solution to the substrate 10 to be processed is started. It is confirmed whether or not it has become (S109). The reason why the initial rotational speed is 180 rpm is that the rotational speed is a control limit value based on the performance of the rotary drive motor 3. Therefore, when the rotation of the substrate to be processed 10 reaches the initial rotation speed, the rotation speed is controlled to be constant as shown in FIG. Next, when the discharge pressure of the chemical liquid is stable at 0.2 MPa, and the rotation of the substrate to be processed 10 is also stabilized at the initial rotation speed (S109: YES), the chemical liquid supply nozzle that has been on the tray 7a until now is obtained. The movement of 8 is started (S110).
[0036]
  The chemical supply nozzle 8 has a positive range in one direction with respect to the center of the substrate 10 to be processed, and a negative range in the opposite direction. Therefore, the chemical supply nozzle 8 is positioned on the tray 7a arranged in the minus range until the movement is started in S110 (see FIG. 4A), and in the plus direction toward the center of the substrate about 10 seconds after the processing is started. You can start moving. The position of the chemical solution supply nozzle 8 is detected by a signal from a detector such as an encoder, and it is confirmed whether or not the center of the substrate (nozzle origin) has been reached (S111). As shown in FIG. 4A, the chemical solution supply nozzle 8 reaches the nozzle origin at 12 seconds after the start of processing (S111: YES), and the chemical solution discharge stabilization processing (S2) is thereby completed. Accordingly, when the chemical solution discharge stabilization process is completed, the chemical solution supply nozzle 8 is positioned at the center of the substrate 8 as shown in FIG. 4, the discharge pressure of the chemical solution is 0.2 MPa, and the substrate 10 is processed. The rotation speed is stable at 180 rpm.
[0037]
  Therefore, the coating process for actually discharging the chemical solution onto the substrate 10 is started immediately after the chemical solution supply nozzle 8 reaches the center of the substrate. In FIG. 3, the time when the chemical solution supply nozzle 8 is located at the center of the substrate to be processed 10 is shown as 0 o'clock.
  The spiral application control returns to the control flow shown in FIG. 5 and the current value of each device is confirmed (S3). That is, the number of rotations of the rotation drive motor 3, the position of the chemical solution supply nozzle 8, and the discharge pressure of the chemical solution supply pump 16 are taken in as current values of each device based on information sent to the controllers 31, 32, and 33. The current value of each device is confirmed every unit time while the chemical solution supply nozzle 8 moves.
[0038]
  Next, when a chemical solution is applied to the substrate 10 to be processed, it is checked what state the peripheral portion of the liquid film is in (S4). That is, when the chemical solution supply nozzle 8 is located at the outermost diameter of the chemical solution supply region of the substrate 10 to be processed, the number of rotations of the substrate 10 to be processed so that the chemical solution applied on the substrate 10 is not scattered, Each value of the chemical solution supply amount qout per unit length of the assumed trajectory of the dropped chemical solution applied to the substrate to be processed 10 is obtained.
[0039]
  Then, based on the current value of each device at the arbitrary position thus obtained and the peripheral value, the movement speed of the chemical supply nozzle 8 (movement position of the chemical supply nozzle 8), the chemical supply speed ( For the three parameters of the chemical solution discharge pressure and the rotation speed of the substrate 10 to be processed, control values are calculated based on a preset higher-order function (S5). At this time, it should be noted that the chemical applied on the substrate to be processed 10 does not flow due to centrifugal force, but the higher order function is set in consideration of such points. Therefore, the setting of higher order functions will be described below.
[0040]
  First, when the coating amount per unit area is constant, the diameter is particularly small in the center, but the discharge pressure of the chemical solution cannot be reduced to 0.2 MPa or less, so that the chemical solutions adjacent in the radial direction do not overlap. It is necessary to increase the radial movement pitch dr generated each time the substrate 10 makes one round. On the other hand, since the diameter increases with the movement of the chemical solution supply nozzle 8, it is necessary to reduce the radial movement pitch dr. Therefore, the movement pitch dr in the radial direction of the chemical solution supply nozzle 8 for applying the chemical solution spirally on the substrate 10 to be processed is determined by a value obtained by multiplying the immediately preceding movement pitch dr0 by a change rate a smaller than 1. The interval is set so as to be gradually narrowed while moving toward the periphery of the liquid film.
[0041]
  Specifically, every time the substrate 10 to be processed rotates once, the moving pitch change rate a of the chemical solution supply nozzle 8 is reduced to 0.99 (decrease by 1%). If the number of spirals based on the center of the substrate to be processed 10 is defined as a circumferential value n (n> 0 real number), this circumferential value n is used, and the movement pitch d1 of the chemical solution supply nozzle 8 at n = 1 is used. The movement pitch dn in the radial direction at the circumferential value n is
    dn = d1 × a^n-1                                       (1)
        = D1 x 0.99^n-1
It can be expressed as. The radial position Rn of the chemical solution supply nozzle 8 at this time is
    Rn = d1 × (1-a^n-1) / (1-a) (2)
        = D1 x (1-0.99^n-1) / (1-0.99)
It can be expressed as.
[0042]
  When dn is constant (a = 1), the area change rate at the distance r from the center of the substrate to be processed 10 is 2πr. Since the area change rate at the distance r from the center of the substrate 10 to be processed is proportional to the distance r from the center of the substrate 10 to be processed, the chemical solution supply outermost diameter rout and the expected trajectory of the dropped chemical solution at that time It is necessary to make the ratio of the chemical supply amount qout per unit length equal to the ratio of the distance r from the center of the substrate 10 to be processed and the chemical supply amount q.
  Therefore, the chemical supply amount q at the distance r from the center of the substrate to be processed 10 is
    q = qout × r / rout (3)
It is necessary to.
[0043]
  Further, between the chemical solution supply speed Vr, the rotation speed Wr, and the chemical solution supply amount q at the distance r from the center of the substrate 10 to be processed,
    q = Vr / Wr (4)
The relationship is established.
  Therefore, from equations (3) and (4)
    Vr / Wr = (Vrout / Wrout) × (r / rout) (5)
The chemical solution supply speed Vr and the rotation speed Wr at a distance r from the center of the substrate 10 to be processed that satisfy the above conditions may be determined. Here, Vrout and Wrout are respectively the chemical solution supply speed and the rotational speed at the radial position Rn of the chemical solution supply nozzle 8 at the outermost diameter rout.
[0044]
  Accordingly, the same rate of change is given to the chemical solution supply speed Vr and the rotation speed Wr, and the load distribution of the control is distributed at the distance r from the center of the substrate to be processed 10 in consideration of the limits of the chemical supply pump control and the rotation speed control. Coefficient b'(B' = 1 / b)Can be expressed as the following equation.
    Vr = Vrout × b'/ (Rout / r)^1/2                   (6)
    Wr = Wrout × (rout / r)^1/2/ B'                   (7)
[0045]
  In the present embodiment, since dn is not constant but varies in a geometric series, equations (6) and (7) are
    Vr = Vrout / (rout / r)^1/2× (b'× ((Rn + 0.5-Rn-0.5) / (Rnout + 0.5-Rnout-0.5))^1/2(8)
    Wr = Wrout × (r / rout)^1/2/ (B'× ((Rn + 0.5-Rn-0.5) / (Rnout + 0.5-Rnout-0.5))^1/2(9)
Each can be replaced.
[0046]
  In addition, the centrifugal force F applied to the liquid film in the minute unit area at the distance r from the center of the substrate to be processed 10 uses the specific gravity c of the liquid,
    F = mrWr²
      = C × (qout / 2π) × (r / rout) Wr²           (10)
It can be expressed.
  When the relationship in which the centrifugal force F becomes constant is determined, if C = c (qout / 2πrout),
    Wr = (F / C)^1/2 ×(1 / R)^1/2                  (11)
It becomes.
[0047]
  From equations (7) and (11), the rotational speed Wrout at the outermost diameter rout is determined from the lower limit centrifugal force F, constant C, and coefficient b that cause fluidity in the spread liquid film.'(Usually 1)
    Wrout ≤ (F / C)^1/2 Xb'/ R out ^1/2                              (12)
By defining as described above, it is possible to form a liquid film without uneven distribution of the liquid film within the surface of the substrate to be processed 10 without discharging the chemical solution outside the substrate 10 to be processed. Therefore,
    Wr ≦ (F / C)^1/2 × (1 / r) ^1/2                      (13)
  The rotation speed Wr and the chemical solution supply speed Vr may be any value as long as the combination satisfies the expressions (4) and (13).
  Considering the above, each higher order function with respect to the processing time t with respect to the moving speed for determining the moving position of the chemical solution supply nozzle 8, the chemical solution discharge pressure from the chemical solution supply nozzle 8, and the rotation speed of the substrate 10 to be processed. You can ask for.
[0048]
  That is, the high-order function for controlling the three parameters is determined by the theoretical value obtained according to the following procedure.
  When the chemical solution supply nozzle 8 is moved in the radial direction with respect to the rotating substrate 10 to be processed, one end of the moving region divided every unit time is set as the first position. First, the chemical solution supply nozzle 8 is set in the application region. The rotation speed Wout of the substrate 10 to be processed when it is positioned at the outermost diameter and the chemical solution supply amount qout per unit length of the assumed trajectory of the dropped chemical solution to the substrate 10 to be processed are obtained. Then, based on the set first position, the movement pitch of the chemical liquid supply nozzle 8 at the first position, and the chemical liquid supply amount qout at the outermost diameter, the chemical supply speed at the first position and the processing target The number of rotations of the substrate 10 is determined.
[0049]
  Further, from the rotation angle when the substrate to be processed 10 rotates for a unit time after the chemical solution supply nozzle 8 is positioned at the first position, and the movement pitch of the chemical solution supply nozzle 8 at the first position, the chemical solution supply nozzle A position when 8 moves for a unit time is obtained as the second position. The second position is reset as a new first position in the next unit time until the end of the application region, and the chemical supply speed from the chemical supply nozzle 8 in the first position and the substrate 10 to be processed are set. The determination of the number of rotations and the determination of the second position where the chemical solution supply nozzle 8 is positioned after a unit time are repeated. Therefore, a high-order function for the processing time is determined from the theoretical values thus obtained in order to appropriately control the radial position of the chemical solution supply nozzle 8, the chemical solution supply speed, and the rotational speed of the substrate 10 to be processed.
[0050]
  By the way, in the present embodiment, the higher-order function determined in this way controls each device with respect to three parameters of the nozzle position (a), discharge pressure (b), and substrate rotation speed (c) as shown in FIG. However, in determining this high-order function, the spiral coating process on the substrate 10 to be processed is divided into four stages from the region 1 to the region 4 and is obtained for each region. The boundary of each region here is a change in the value of any one of radial position control (movement speed control), chemical discharge pressure control, and rotational speed control of the substrate 10 to be processed with respect to time t. It is determined on the basis of the music point, and is specifically as follows.
[0051]
  First, the boundary between the region 1 and the region 2 is at the processing time t1, which is an inflection point based on the rotational speed control of the substrate 10 to be processed, and the control limit value of the rotary drive motor 3 that rotates the substrate 10 to be processed. Is set by. At the start of processing in the region 1, when applying spirally from the origin of nozzle movement (the center of the substrate 10 to be processed) to a predetermined distance, the radius is small, so the distance for one round is short, and the discharge pressure of the chemical solution Therefore, 180 rpm, which is the control limit value of the rotary drive motor 3 that rotates the substrate 10 to be processed and moves the chemical solution supply nozzle 8 at a high speed in order to prevent the applied chemical solutions from overlapping each other. Is set. However, as the distance from the center increases, the centrifugal force applied to the applied chemical solution increases. Therefore, in order to prevent the chemical solution from flowing due to the centrifugal force, the rotational speed of the rotary drive motor 3 is increased as the process proceeds. Need to lower. Therefore, the inflection point 1 is the point of time t1 during which the rotational speed of the rotary drive motor 3 is reduced from the control limit value.
[0052]
  Next, the boundary between the region 2 and the region 3 is at a processing time t2 immediately after t1, and is an inflection point based on control of a chemical solution supply speed (discharge pressure) discharged from the chemical solution supply nozzle 8. Since the control limit value of the discharge pressure for discharging the chemical liquid from the chemical liquid supply pump 16 as a fine jet is 0.2 MPa, it cannot be lowered below this, and as described above, the chemical liquid has a control limit value of 0.2 MPa. Was being discharged. However, as the radius of the spiral to be applied increases, the application area also increases. Therefore, in order to make the application amount per unit area constant, the chemical supply pressure is increased by increasing the chemical discharge pressure following the rotation speed of the substrate 10 to be processed. The amount needs to be increased. Therefore, the inflection point 2 is the time point of the processing time t2 when the discharge pressure of the chemical liquid is increased from the control limit value. The reason why the processing times t1 and t2 at the inflection points 1 and 2 are shifted is that the chemical solution on the substrate to be processed 10 flows due to a sudden change in the application state of the chemical solution, and the liquid film does not become uneven. It is for doing so.
[0053]
  Further, the boundary between the region 3 and the region 4 is at the processing time t3, which is also an inflection point based on the control of the chemical solution supply speed (discharge pressure) discharged from the chemical solution supply nozzle 8. This is because the control limit value of the discharge pressure that can be applied to the chemical liquid by the chemical liquid supply pump 16 is 0.35 MPa, and thus cannot be increased any more, and the discharge pressure that has been increased in the region 3 reaches the limit. . Therefore, the inflection point 3 is the time point of the processing time t3 when the discharge pressure of the chemical solution reaches the upper control limit value.
[0054]
  By the way, the boundary of each region that divides the high-order function is determined based on the inflection point in the radial position control of the chemical solution supply nozzle 8, and this is made to approximate the high-order function to the theoretical value. In this case, it is difficult to approximate a high-order function at this inflection point, and the error becomes large. Therefore, the boundary of the region is not limited to the inflection point of the value such as the radial position control of the chemical solution supply nozzle 8 with respect to time t, but is defined by the portion where the error of the higher-order function obtained so as to approximate the theoretical value increases. It can be said that.
  In addition, in order to prevent a sudden change in the application state, it is necessary to make the high-order functions obtained in this way continue at the boundary of each region. Therefore, the order and coefficient of the high-order function are determined in consideration of the continuity between these regions.
[0055]
  Returning to the control flow shown in FIG. 5 again, the calculated values of the rotation speed of the substrate 10 to be processed, the moving speed of the chemical solution supply nozzle 8 and the discharge pressure of the chemical solution calculated based on the higher order function are obtained in S3. The current value is compared (S6). If the two values match as a result of the comparison, the calculated value is determined as an output value (S7). On the other hand, if the two values do not match, a control value error correction process is performed (S8). Is determined as an output value (S7). In the error correction process at this time, in addition to the calculated value and the current value, a value before the substrate to be processed 10 makes one revolution is also used. This is because in the spiral application in which the chemical solution is applied spirally, it is necessary to control the application state of the chemical solution in units of one rotation when the chemical solution supply nozzle 8 is viewed in the moving direction in addition to the tangential control in the unit time. .
  The output value thus determined is output as a control signal from each of the controllers 31, 32 and 33 to the rotation drive motor 3, the nozzle moving motor 12 and the air pressure adjusting valve 18 according to a command from the main controller 30 (S9).
[0056]
  Accordingly, the substrate to be processed 10 is rotated at a predetermined number of revolutions by the rotation drive motor 3, the nozzle moving motor 12 and the air pressure adjusting valve 18 which have received the control signal, and the chemical solution supply nozzle is rotated on the substrate 10 to be processed at a predetermined speed. 8 moves, and the chemical solution is applied to the substrate 10 to be processed at a predetermined discharge pressure from the chemical solution supply nozzle 8. And control of each apparatus is updated by the control signal transmitted for every unit time, and the process of S3-S9 is repeated until it reaches the peripheral part of a liquid film.
  At the position corresponding to the peripheral portion of the liquid film, there is a receiving tray 7b disposed on the lid 6a of the processing container 6. When it is detected that the position of the chemical solution supply nozzle 8 has reached the receiving tray 7b, the completion of the substrate coating is confirmed. (S10).
[0057]
  And when the chemical | medical solution supply nozzle 8 reaches even the outer side receiving tray 7b and the completion | finish of board | substrate application | coating is confirmed (S10: YES), it transfers to a chemical | medical solution discharge completion process (S11). FIG. 7 is a diagram showing a sub-flow showing this chemical liquid discharge end process.
[0058]
  The chemical liquid discharged from the chemical liquid supply nozzle 8 is received by the receiving tray 7b. Therefore, the chemical liquid discharge shutoff valve 24 of the chemical liquid supply pump 16 is closed by the start of the chemical liquid discharge end process (S201), and the pressure in the closed pump chamber 25 is reduced to 0 MPa by adjusting the pressure of the air pressure supply valve 18. (S202). Such pressure reduction to 0 MPa is detected by the pressure sensor 22, and confirmation of completion of pressure reduction is performed (S203). When the pressure is reduced to 0 MPa (S203: YES), the chemical solution supply shutoff valve 23 of the chemical solution supply pump 16 is opened (S204), the diaphragm 21 is pulled up, and the chemical solution is sucked from the chemical solution tank 15 into the chemical solution supply pump 16. (S205). If the suction of the chemical liquid is completed (S206: YES), the chemical liquid supply cutoff valve 23 is closed and the chemical liquid discharge end process is completed (S207).
[0059]
  After the chemical solution discharge end process (S11), the substrate 10 on which the liquid film is formed is subjected to a leveling process so that the inclination of the substrate 10 is parallel to the image plane of the projection lens ( Next, a drying process for drying and removing the solvent in the liquid film is performed (S13). For the drying process, heating, drying under reduced pressure below the saturated vapor pressure of the solvent, or a method of contacting the surface with an air current is used.
[0060]
  Therefore, according to the liquid film forming method of the present embodiment described above, the movement position (movement speed) of the chemical liquid supply nozzle 8, the supply speed (discharge pressure) of the liquid discharged from the chemical liquid supply nozzle 8, and the processing target Since the number of rotations of the substrate 10 is controlled at the same time, it is possible to perform appropriate control in consideration of making the amount of the chemical solution applied per unit area constant and preventing the flow of the chemical solution due to centrifugal force. As a result, the reliability of coating control for uniformizing the liquid film in the spiral coating on the substrate to be processed 10 could be improved.
  In particular, since the simultaneous control of these three parameters is performed based on a preset higher-order function, the control can be easily performed.
[0061]
  In addition, by setting the higher-order function divided into a plurality of regions 1 to 4, it is possible to perform appropriate control according to changing states such as centrifugal force. And by providing the boundary of the area | regions 1-4 in the control limit value of the rotational drive motor 3 or the chemical | medical solution supply pump 16, appropriate control according to the performance of the said apparatus which comprises a liquid film forming apparatus can be performed. It became so. Furthermore, since the boundaries of the regions 1 to 4 are defined by the inflection points of any of the three parameters, the control can be performed in the most preferable state.
[0062]
  As mentioned above, although one Embodiment of the liquid film formation method was described, this invention is not limited to this, A various change is possible.
  For example, the control limit value of the discharge pressure is determined by the chemical solution supply pump 16 and the like described in the present embodiment, and it is natural that the value is different if devices having different performances are used. In such a case, the position of the inflection point is also different, and the higher order function for controlling the three parameters of the nozzle position, the discharge pressure, and the substrate rotation speed corresponding to the processing time t is also changed, and the control is different from that in FIG.
  For example, in the above-described embodiment, the chemical solution supply nozzle 8 is applied when moving from the center of the substrate to be processed 10 to the peripheral portion. However, the chemical solution supply nozzle 8 may be moved in the opposite direction.
  Moreover, in the said embodiment, although the moving pitch of the chemical | medical solution supply nozzle 8 decreased at a fixed rate, it is made to become small when seeing a moving pitch from the center part side to the peripheral part side, It is not always necessary to decrease the entire moving region of the chemical solution supply nozzle 8. This is because it may be necessary to make the movement pitch constant for some sections depending on the performance of each device.
[0063]
【The invention's effect】
  Therefore, according to the liquid film forming method of the present invention, the moving position of the liquid supply unit, the supply speed of the liquid discharged from the liquid supply unit, and the number of rotations of the substrate to be processed are based on a preset higher order function. Since these three parameters are obtained at any time and controlled at the same time, it is possible to improve the reliability of coating control for uniformizing the liquid film in spiral coating in which a liquid is applied by drawing a spiral trajectory on the substrate to be processed. It became so.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a spiral coating apparatus for executing a liquid film forming method according to the present invention.
FIG. 2 is an image view of spiral coating.
FIG. 3 is a characteristic diagram of nozzle position (a), discharge pressure (b), and substrate rotation speed (c) corresponding to a processing time t controlled based on a high-order function.
FIG. 4 is a characteristic diagram of a nozzle position (a), a discharge pressure (b), and a rotation speed (c) of a substrate to be processed corresponding to a processing time in a chemical liquid discharge stabilization process.
FIG. 5 is a diagram illustrating a coating control flow.
FIG. 6 is a diagram showing a sub-flow showing a chemical liquid discharge stabilization process.
FIG. 7 is a diagram showing a sub-flow showing a chemical solution discharge end process.
[Explanation of symbols]
1 Spiral coating device
3 Rotation drive motor
4 Rotary table
8 Chemical supply nozzle
10 Substrate
12 Nozzle movement motor
16 Chemical supply pump
18 Pneumatic supply valve
22 Pressure sensor
30 Main controller
31 Controller for rotation
32 Nozzle movement controller
33 Controller for pump

Claims (14)

A step of setting one end of a moving section of a liquid supply unit that discharges liquid while moving in a radial direction with respect to a rotating substrate to be processed as a first position;
The number of rotations of the substrate to be processed when the liquid supply unit is positioned at the outermost diameter of the liquid supply region of the substrate to be processed and the liquid supply per unit length of the assumed trajectory of the liquid dropped onto the substrate Determining the quantity q out ;
Setting the movement pitch so that the movement pitch in the radial direction of the liquid supply part that occurs each time the substrate to be processed makes one round when the liquid supply part exists at an arbitrary position;
From the first position, the movement pitch of the liquid supply unit at the first position, and the liquid supply amount qout , the liquid supply speed from the liquid supply unit at the first position and the substrate rotation speed are determined. And a process of
The liquid after a unit time from the rotation angle when the substrate to be processed is rotated for a unit time after the liquid supply unit is positioned at the first position and the moving pitch of the liquid supply unit at the first position. Determining a second position at which the supply is located;
Until the second position reaches the other end of the moving section, the second position is reset as a new first position, and the liquid supply speed from the liquid supply unit and the substrate to be processed at the first position are rotated. Determining the number, the relationship between the liquid supply speed and the radial position of the liquid supply unit with respect to time, and the relationship between the rotational speed of the substrate to be processed and the radial position of the liquid supply unit with respect to time as functions When,
Based on the determined function, it is checked whether the radial position of the liquid supply unit, the liquid supply speed and the calculated control value of the substrate rotation speed to be processed match the current value, and the control value A method of forming a liquid film on the substrate to be processed by repeatedly performing error correction . In the liquid film formation method of Claim 1,
The moving direction of the liquid supply section that moves in the radial direction with respect to the substrate to be processed is from the central portion side to the peripheral portion side, or from the peripheral portion side to the central portion side, and the liquid film forming process accompanying the movement is performed in unit time. A liquid film is formed on the substrate to be processed by repeatedly controlling the radial position of the liquid supply unit, the liquid supply speed, and the rotation speed of the substrate to be processed according to the control value obtained every time. Film forming method. In the liquid film formation method of Claim 1 or Claim 2,
In order to apply feedback not only in the immediately preceding control value but also in the radial direction of the substrate to be processed, the control value before one rotation of the substrate to be processed is also used when correcting the control value calculated based on the function. The liquid film formation method characterized by the above-mentioned. In a liquid film forming method for forming a liquid film on a substrate to be processed by drawing a spiral trajectory of the liquid on the substrate to be processed by discharging the liquid from a liquid supply unit that moves in a radial direction on the substrate to be rotated . ,
The liquid supply speed V at the radial position r from the center of the substrate to be processed of the liquid supply unit so that the liquid discharged from the liquid supply unit and placed on the substrate to be processed does not move by centrifugal force; In the case where the rotation speed W of the substrate to be processed is decreased and the supply speed V of the liquid is increased while maintaining a relationship in which the product of the rotation speed W of the substrate to be processed is constant.
Functions for controlling the moving position of the liquid supply unit, the supply speed of the liquid discharged from the liquid supply unit, and the rotation speed of the substrate to be processed are set in advance according to the processing time t. ,
Control is performed while determining the moving position of the liquid supply unit at the processing time t, the supply speed of the liquid ejected from the liquid supply unit, and the rotation speed of the substrate to be processed based on the function. A liquid film forming method. In the liquid film formation method of Claim 4 ,
A process of forming a liquid film on the substrate to be processed by the liquid discharged from the liquid supply unit is divided into a plurality of regions, and the function is provided for each region. Forming method. In liquid film forming method described 請 Motomeko 5,
A liquid film forming method , wherein the boundary of the region is provided in a portion where an error in the function becomes large when the function is obtained so as to approximate a theoretical value . In liquid film forming method described 請 Motomeko 5,
The boundary of the region is provided when the rotation speed control of the substrate to be processed reaches a control limit value or when the liquid supply speed of the liquid discharged from the liquid supply unit reaches the control limit value. A method for forming a liquid film. In liquid film forming method described 請 Motomeko 5,
The boundary of the region is an inflection point of any of the following values: movement position control of the liquid supply unit with respect to processing time t, supply speed control of the liquid discharged from the liquid supply unit, and rotation speed control of the substrate to be processed A method for forming a liquid film, characterized in that In the liquid film formation method in any one of Claim 5 thru | or 8,
A liquid film forming method, wherein a function order and a coefficient are determined so that a function of a processing time t is continuous at a boundary of the region . In the liquid film formation method in any one of Claim 4 thru | or 9 ,
The liquid film forming method characterized in that the rotational speed control of the substrate to be processed is performed so that the sign of the rotational tangential acceleration is not reversed, and the liquid supply speed is controlled reflecting the control. . In the liquid film formation method in any one of Claims 4 thru | or 10,
With respect to the number of rotations W out of the substrate determined by the outermost diameter r out of the substrate to be processed and the liquid supply speed V out from the liquid supply unit ,
The substrate rotation speed W when the liquid supply unit is located at a distance r from the substrate center is determined by the product of the square root of (r out / r) and the coefficient b and W out , and the supply speed V is V out ( A liquid film forming method characterized by being determined by a value obtained by dividing a square root of r out / r) by a coefficient b . A step of setting one end of a moving section of a liquid supply unit that discharges liquid while moving in a radial direction with respect to a rotating substrate to be processed as a first position;
The number of rotations of the substrate to be processed when the liquid supply unit is positioned at the outermost diameter of the liquid supply region of the substrate to be processed and the liquid supply per unit length of the assumed trajectory of the liquid dropped onto the substrate Determining the quantity q out ;
From the first position, the movement pitch of the liquid supply unit at the first position, and the liquid supply amount qout , the liquid supply speed from the liquid supply unit at the first position and the substrate rotation speed are determined. And a process of
The liquid after a unit time from the rotation angle when the substrate to be processed is rotated for a unit time after the liquid supply unit is positioned at the first position and the moving pitch of the liquid supply unit at the first position. Determining a second position at which the supply is located;
Until the second position reaches the other end of the moving section, the second position is reset as a new first position, and the liquid supply speed from the liquid supply unit and the substrate to be processed at the first position are rotated. Determining the number, the relationship between the liquid supply speed and the radial position of the liquid supply unit with respect to time, and the relationship between the rotational speed of the substrate to be processed and the radial position of the liquid supply unit with respect to time as functions When,
Based on the determined function, it is checked whether the radial position of the liquid supply unit, the liquid supply speed and the calculated control value of the substrate rotation speed to be processed match the current value, and the control value A method of forming a liquid film on the substrate to be processed by repeatedly performing error correction . In the liquid film formation method of Claim 12 ,
The moving direction of the liquid supply section that moves in the radial direction with respect to the substrate to be processed is from the central portion side to the peripheral portion side, or from the peripheral portion side to the central portion side, and the liquid film forming process accompanying the movement is performed in unit time. A liquid film is formed on the substrate to be processed by repeatedly controlling the radial position of the liquid supply unit, the liquid supply speed, and the rotation speed of the substrate to be processed according to the control value obtained every time. Film forming method. In the liquid film formation method of Claim 12 or Claim 13,
In order to apply feedback not only in the immediately preceding control value but also in the radial direction of the substrate to be processed, the control value before one rotation of the substrate to be processed is also used when correcting the control value calculated based on the function. The liquid film formation method characterized by the above-mentioned.

Images