JP2010042325A - Coating method and coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating method capable of coating the surface of a base with a solution of a high viscosity at uniform film thickness, and a coating apparatus. <P>SOLUTION: A chemical solution nozzle 14 is provided so that the distance L between the nozzle 14 and the base 2 is 10 mm and the nozzle starts the discharge of a polyimide solution in a stationary state in which the rotation of the base 2 is stopped. In a time elapse of 5 sec, a motor 13 for rotating the base 2 starts the rotation of the base 2 to be raised in its number of rotations and a nozzle-raising and-lowering cylinder 15 starts the falling of the chemical solution nozzle 14 in the direction D shown by an arrow, that is, in a vertical direction. In a time elapse of 1 sec after the start of the rotation of the base 2, the nozzle-raising and-lowering cylinder 15 stops the falling of the chemical solution nozzle 14. In this case, the distance L between the nozzle 14 and the base 2 becomes 2 mm. At the same time, the motor 13 for rotating the base 2 stops the rising of the number of rotations of the base 2 to set the number of rotations of the base 2 to 1,500 rpm. In a time elapse of 5 sec after the distance L between the nozzle 14 and the base 2 becomes 2 mm, the chemical solution nozzle 14 stops the discharge of the polyimide solution. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coating method and a coating apparatus for coating a solution on a substrate surface, and more specifically, a high-viscosity solution such as polyimide is coated on a substrate surface of a semiconductor element or the like to improve film thickness unevenness after coating. The present invention relates to a coating method and a coating apparatus.

  There are two coating methods for applying the solution to the substrate surface: a method in which the solution is discharged and applied in a stationary state without rotating the substrate (hereinafter referred to as “substrate stationary application method”), and a solution in which the substrate is rotated. There is a coating method (hereinafter referred to as “substrate rotation coating method”).

  The base static coating method is a method used when the surface of the base has a large unevenness, but the film thickness in the vicinity of the center of the base becomes thinner than the film thickness in the peripheral part, and the uniformity tends to be inferior. The substrate spin coating method can improve the uniformity as compared with the substrate static coating method, but there are portions where the solution is not applied when the surface irregularities of the substrate are large.

  FIG. 4 is a diagram illustrating a state in which a low-viscosity solution and a high-viscosity solution are discharged from the nozzle to the substrate. When a low-viscosity solution of less than 250 cp (0.25 Pascal seconds) is discharged at a position where the nozzle is low with respect to the substrate, the substrate static coating method has a low rise of the solution and the nozzle and the solution do not contact each other. In the substrate spin coating method, a candy-like state, that is, a state in which the candy is long in the form of a thread does not occur.

  When a high-viscosity solution of 250 cp or more is discharged at a position where the nozzle is low with respect to the substrate, in the substrate static coating method, the raised height of the discharged solution is high, and the height of the nozzle from the substrate surface is 2 to 2. If it is 3 mm, the tip of the nozzle may come into contact with the solution, and the solution may adhere to the nozzle. The solution adhering to the tip of the nozzle becomes a foreign substance and generates a pattern defect, which causes a decrease in yield. In the substrate spin coating method, since the position of the nozzle is low, the solution does not become a candy-like state.

  When a high-viscosity solution of 250 cp or more is discharged at a high position with respect to the base, the base static coating method has a high nozzle position from the base surface even if the height of the discharged solution rises. Therefore, the solution does not contact the nozzle tip. In the substrate spin coating method, since the position of the nozzle is high, the solution is in a candy-like state, and the solution in the candy-like state falls on the surface of the substrate at the end of discharge, and the film thickness of that portion becomes thick. A solution having a large film thickness causes pattern defects and causes a decrease in yield.

  As a first conventional technique based on the substrate spin coating method, there is a semiconductor manufacturing apparatus described in Patent Document 1. In this semiconductor manufacturing apparatus, a resist nozzle for discharging a photoresist onto a wafer can be moved from the center of the wafer to the periphery of the wafer by a motor. The distance between the wafer and the resist nozzle can also be changed by the nozzle up / down cam. The wafer is rotated by being vacuum-sucked by the wafer chuck, and the distance between the wafer and the resist nozzle is larger when the nozzle is at the periphery than when the nozzle is at the center.

  As a second conventional technique based on the base static coating method, there is a coating film forming apparatus described in Patent Document 2. The coating film forming apparatus includes a spraying device that sprays a coating liquid onto a coating target, and the coating target is placed on a work stage and moved in a horizontal direction, and the coating liquid is applied to the entire surface by the spraying device. Applied. After the coating liquid is applied, the thickness of the formed coating film is measured by a film thickness measuring device. When a portion where the measured film thickness is smaller than the required film thickness is detected, the coating process is again performed by the spraying device, whereby a uniform coating film can be formed on the coating object having an uneven portion on the surface. The application object is not rotated.

  As a third conventional technique based on the base static coating method, there is a processing system described in Patent Document 3. This processing system discharges the processing liquid from the discharge port to the target substrate while keeping the gap between the target substrate on the stage and the discharge port of the coating nozzle constant with respect to the variation in the thickness of the target substrate. . This processing system applies a resist solution with a desired film thickness to a substrate to be processed without rotating the substrate to be processed.

Japanese Patent Laid-Open No. 5-190438 JP 2005-334754 A JP 2005-251864 A

  The polyimide solution is used for forming a protective film or an insulating film of a semiconductor element. In recent years, a semiconductor element using a protective film formed by applying a polyimide solution is resistant to impact, so that the demand for semiconductor elements for mobile phones and automobiles is increasing. Products such as mobile phones and automobiles tend to be miniaturized, and semiconductor elements used in these products are required to be reduced, and the uniformity of the film thickness of the polyimide film formed on the semiconductor elements is also required. Has been.

  However, the polyimide solution has a high viscosity of 250 cp or more, and as shown in FIG. 4, the film thickness varies even if any of the base static coating method and the base spin coating method is used. There is a problem that it cannot be made uniform.

  The first conventional technique is a method of discharging a solution while moving the nozzle from the center of the substrate to the periphery, and is an effective method in the case of a low-viscosity solution. However, a high-viscosity solution such as a polyimide solution is used. In this case, there is a problem that a repellency phenomenon occurs around the base. The repelling phenomenon is a phenomenon in which when a highly viscous solution is discharged to a position shifted from the center of rotation on a rotating substrate, the solution discharged on the substrate flows so as to roll on the substrate surface.

  The second conventional technique is a method of spraying a solution, but a polyimide solution has a high viscosity and cannot be sprayed. The third conventional technique is to keep the gap between the substrate and the discharge port of the coating nozzle constant with respect to the variation in the thickness of the substrate. It does not solve the problem caused by the condition.

  The objective of this invention is providing the coating method and coating device which can apply | coat a highly viscous solution with the uniform film thickness on a base surface.

The present invention is an application method for applying a solution by discharging a solution downward in the vertical direction from a nozzle disposed on the central axis on the upper surface of a base that is rotatable about the central axis extending in the vertical direction,
When the base is stationary between the first distance that is predetermined from the tip of the nozzle to the upper surface of the base and the second distance that is smaller than the predetermined first distance. From the time when the base is rotating, the nozzle is moved in the vertical direction in conjunction with the rotation of the base while the solution is discharged from the nozzle onto the top surface of the base and applied. Is the method.

The present invention also includes a mounting means for mounting the base;
Rotating means for rotating the base placed on the base placing means around a central axis extending in the vertical direction;
Discharging means that is disposed on the central axis and that discharges and applies a solution to the base provided below in the vertical direction;
Moving means for moving the discharge means downward in the vertical direction;
The rotating means and the discharging means are controlled so that the solution is discharged from the discharging means to the upper surface of the base and applied from when the base is stationary to when the base is rotating. Meanwhile, in conjunction with the rotation of the base by the rotating means, the moving means causes the discharge means to be set to a first distance that is predetermined as a distance from the tip of the discharge means to the top surface of the base. And a control means for moving between a predetermined second distance smaller than the distance.

  According to the present invention, when a solution is discharged and applied vertically downward from a nozzle disposed on the central axis on the upper surface of the base that is rotatable about a central axis extending in the vertical direction, the base from the tip of the nozzle is applied. The base is rotating from a state where the base is stationary between a predetermined first distance and a predetermined second distance that is smaller than the predetermined first distance. The nozzle is moved downward in the vertical direction in conjunction with the rotation of the substrate while discharging the solution from the nozzle to the upper surface of the substrate and applying it.

  Therefore, if the coating method according to the present invention is applied, the height of the nozzle can be controlled in conjunction with the rotation of the base, so that even when a highly viscous solution is applied, the solution rises near the center of the base. And the nozzle is in contact with the solution, and the solution is in a candy-like state, that is, the candy candy can be prevented from becoming a long string-like tail, and the solution is applied to the substrate surface with a uniform film thickness. Can do.

  According to the invention, the base is placed by the placing means, and the base placed on the base placing means is rotated around the central axis extending in the vertical direction by the rotating means. The solution is discharged and applied to the base provided below in the vertical direction by the discharge means disposed above, and the discharge means is moved downward in the vertical direction by the moving means. Then, the control means controls the rotating means and the discharging means so that the solution is discharged from the discharging means to the upper surface of the base from when the base is stationary to when the base is rotating. The distance between the tip of the discharge means and the top surface of the base is determined in advance by the moving means in conjunction with the rotation of the base by the rotating means. And a predetermined second distance smaller than the predetermined first distance.

  Therefore, since the height of the nozzle can be controlled in conjunction with the rotation of the base, even if a highly viscous solution is applied, the rise of the solution near the center of the base and the nozzle are in contact with each other, and the solution is water-filled. In other words, it is possible to avoid a state where the candy is in a state of having a long tail like a thread, and the solution can be applied to the substrate surface with a uniform film thickness.

  FIG. 1 is a diagram schematically showing a configuration of a base processing apparatus 1 according to an embodiment of the present invention. The substrate processing apparatus 1 that is a coating device includes a substrate suction chuck 11, a cup 12, a substrate rotation motor 13, a chemical solution nozzle 14, a nozzle upper / lower cylinder 15, a nozzle column 16, an upper sensor 17, a lower sensor 18, and a control unit 19. Consists of. The coating method according to the present invention is processed by the substrate processing apparatus 1.

  A substrate suction chuck 11 serving as a mounting means sucks and mounts the substrate 2 such as a semiconductor element. The cup 12 is a container for collecting the scattered coating liquid when a solution (hereinafter referred to as “coating liquid”) applied to the base 2 is scattered from the base 2 by the rotation of the base 2. The substrate rotation motor 13 serving as a rotating means has a rotation drive shaft coupled to the substrate suction chuck 11, and rotates the substrate 2 placed on the substrate suction chuck 11 by rotating the rotation drive shaft. . The base rotation motor 13 rotates the base 2 or stops the rotation in accordance with an instruction from the control unit 19. The number of rotations for rotating the base 2 is instructed from the control unit 19.

  The chemical liquid nozzle 14 that is a nozzle is a discharge means that discharges the coating liquid in the vertical direction from the tip and applies it to the substrate 2, and is held by the nozzle column 16. The chemical nozzle 14 starts discharging the coating liquid or stops discharging the coating liquid according to an instruction from the control unit 19. The nozzle upper / lower cylinder 15 changes the distance L between nozzle bases between the tip of the chemical solution nozzle 14 and the upper surface of the base 2 by moving the nozzle column 16 in the vertical direction according to an instruction from the control unit 19. The nozzle column 16 holds the chemical solution nozzle 14 and is moved in the vertical direction by the nozzle vertical cylinder 15. The nozzle upper / lower cylinder 15 and the nozzle column 16 are moving means.

  The upper sensor 17 is a sensor that detects that the nozzle column 16 is positioned at a position where the distance L between the nozzle substrates is a first predetermined distance, for example, 10 mm, and the nozzle column 16 is positioned at that position. If it is detected, the control unit 19 is notified of this. The lower sensor 18 is a sensor that detects that the nozzle column 16 is positioned at a position where the distance L between the nozzle substrates is a predetermined second distance, for example, 2 mm, and the nozzle column 16 is positioned at that position. If it is detected, the control unit 19 is notified of this. When the inter-nozzle base distance L is 2 mm, the chemical nozzle 14 is positioned at the position of the chemical nozzle 14a shown in FIG.

  The control unit 19 which is a control means is constituted by, for example, a central processing unit (hereinafter referred to as “CPU”) and a semiconductor memory. The CPU executes a control program stored in the semiconductor memory, whereby the base rotation motor 13 is executed. The chemical nozzle 14 and the nozzle upper / lower cylinder 15 are controlled. The coating solution is a high-viscosity solution having a viscosity of 250 cp (0.25 Pascal second) to 4500 cp, such as a polyimide solution.

  FIG. 2 is a graph showing an application sequence in which the substrate processing apparatus 1 applies a polyimide solution. FIG. 2A is a diagram showing the relationship between the passage of time and the number of rotations of the base 2, wherein the horizontal axis is time (seconds) and the vertical axis is the base rotation number (rpm: rotation / second). FIG. 2B is a diagram showing the relationship between the passage of time and the distance L between nozzle bases, the horizontal axis is time (seconds), and the vertical axis is the nozzle between the tip of the chemical nozzle 14 and the upper surface of the base 2. Distance between substrates L (mm).

  At the time “0”, the distance L between the nozzle bases is 10 mm, the rotational speed of the base 2 is 0 rpm, that is, the stationary state where the rotation of the substrate 2 is stopped. The chemical nozzle 14 starts discharging the polyimide solution in response to an instruction from the control unit 19 at time “0”. When 5 seconds have elapsed from time “0”, the base rotation motor 13 starts rotating the base 2 according to an instruction from the control unit 19, and at the same time, the nozzle upper and lower cylinders 15 are controlled by the control unit. In response to an instruction from 19, the chemical liquid nozzle 14 starts to descend in the direction of arrow D, that is, the vertical direction. During this time, the chemical nozzle 14 continues to discharge the polyimide solution. The discharge amount of the solution per unit time is determined in advance and does not vary during discharge.

  When 6 seconds have elapsed from time “0”, that is, when acceleration time of 1 second has elapsed since the rotation of the base 2 has started, the nozzle upper and lower cylinders 15 are moved down by the instruction from the control unit 19. To stop. When the acceleration time of 1 second elapses after the rotation of the base 2 starts, the distance L between the nozzle bases is 2 mm. At the same time, the substrate rotation motor 13 stops the increase in the number of rotations of the substrate 2 according to an instruction from the control unit 19. When the acceleration time of 1 second elapses after the rotation of the base plate 2 starts, the rotation speed of the base plate 2 becomes a first predetermined rotation number, for example, 1500 rpm.

  When 11 seconds have elapsed from the time “0”, that is, when 5 seconds have elapsed since the distance L between the nozzle bases became 2 mm, the chemical solution nozzle 14 is continued by the instruction from the control unit 19. Stop discharging. Therefore, the chemical nozzle 14 discharged the polyimide solution for 11 seconds from time “0”. After 11 seconds have elapsed from time “0”, the substrate rotation motor 13 restarts the increase in the rotation number of the substrate 2 in accordance with an instruction from the control unit 19, and the rotation number of the substrate 2 until the rotation number reaches 3000 rpm. To raise.

  Thus, even when the polyimide solution was applied to the upper surface of the substrate 2 in a state where the substrate 2 was stationary and the polyimide solution swelled on the upper surface of the substrate 2, the distance L between the nozzle substrates was 10 mm. The chemical nozzle 14 does not come into contact with the polyimide solution. Further, when the rotation of the substrate 2 is started in order to spread the raised polyimide solution applied to the upper surface of the substrate 2, the height of the raised polyimide solution is reduced. When the height of the polyimide solution starts to decrease, the chemical nozzle 14 starts to descend. When the rotation speed of the base 2 increases and reaches 1500 rpm, the distance L between the nozzle bases is controlled to be 2 mm. The chemical nozzle 14 discharges the polyimide solution while the base 2 is rotating at 1500 rpm. However, since the distance L between the nozzle bases is 2 mm, the polyimide solution is in a candy-like state, that is, the candy is long in the form of a thread. It will not be in a state of pulling.

  FIG. 3 is a diagram showing the film thickness distribution of the polyimide solution formed on the substrate 2. The horizontal axis is the base measurement point, the distance (cm) in the radial direction from the center of the base 2, and the vertical axis is the polyimide film thickness (nm). FIG. 3A shows a film thickness distribution when a polyimide solution is applied to the substrate 2 using a conventional substrate static application method. The polyimide film thickness at the central position is 1035 (nm), while the polyimide film thickness at 1 to 3 cm from the center is 1060 to 1123 (nm), and the polyimide film thickness at the central position is the periphery. The value is smaller than the polyimide film thickness at the position.

  FIG. 3B shows the film thickness distribution when the polyimide solution is applied to the substrate 2 using the substrate spin coating method according to the prior art. The polyimide film thickness at the central position is 1023 (nm), whereas the polyimide film thickness at 1 to 3 cm from the center is 996 to 1004 (nm), and the polyimide film thickness at the central position is the periphery. The value is larger than the polyimide film thickness at the position. FIG. 3C shows a film thickness distribution when the polyimide solution is applied to the substrate 2 by the substrate processing apparatus 1 according to the present invention. The polyimide film thickness is 1000 to 1005 (nm) at both the central position and the peripheral position, and the polyimide solution is applied with a uniform film thickness.

  That is, the substrate processing apparatus 1 can make the film thickness of the polyimide solution applied to the substrate 2 uniform even when a highly viscous solution, for example, a polyimide solution is applied to the substrate 2.

  In the embodiment described above, the predetermined first distance is 10 mm, but it may be any distance between 7 and 10 mm. The predetermined second distance is 2 mm, but may be any distance between 2 and 3 mm. Although the predetermined first rotation speed is 1500 rotations / second, it may be any rotation speed between 500 and 2000 rotations / second. Although the acceleration time is 1 second, it may be any time between 0.5 and 2 seconds. The acceleration time is a time during which the solution spreads in a circular shape when accelerating, that is, when the state of the substrate 2 changes from stationary to rotating, and since the solution is also discharged during acceleration, the discharged solution does not become a candy-like shape. .

  Furthermore, although the time for applying the polyimide solution in a stationary state where the substrate 2 is stopped is 5 seconds, it may be any time between 1 and 5 seconds. The time during which the solution is discharged while the substrate 2 is stationary is that the high-viscosity solution does not rise and the height does not become too high, and if the discharge time is short, application failure occurs, so that application failure does not occur It is. The time for applying the polyimide solution while the base is rotating at a predetermined first rotation speed is set to 5 seconds, but may be any time between 2 and 5 seconds. The time for discharging the solution while rotating at the first rotation speed is the time for the highly viscous solution to spread over the entire surface of the substrate 2. In order to suppress variations in film thickness, the solution is discharged until the spread is completed.

  Furthermore, in the above-described embodiment, the polyimide solution is used as the high-viscosity solution. However, the polyimide solution is not limited to the polyimide solution. For example, the high-viscosity solution for forming a resist film of a photosensitive resin is used. May be.

  Thus, when the base 2 is stationary, the high-viscosity solution is discharged, and the rise of the high-viscosity solution near the center of the base 2 is higher than the height of the rise of the low-viscosity solution. Even if it becomes, since the position of the chemical | medical solution nozzle 14 is made high, it can prevent that the chemical | medical solution nozzle 14 touches the rising part of a solution. Further, when the base 2 is rotating at the first rotation speed, the position of the chemical nozzle 14 is lowered to discharge the high-viscosity solution, so that the high-viscosity solution is in a candy-like state, that is, the candy candy. Can be prevented from having a long tail in the form of a thread. Therefore, when the substrate processing apparatus 1 according to the present invention and the coating method according to the present invention processed by the substrate processing apparatus 1 are applied, a high-viscosity solution such as a polyimide solution is uniformly formed on the upper surface of the substrate 2. Can be applied. Since it can apply | coat with a uniform film thickness, the pattern defect which generate | occur | produces by film thickness dispersion | variation can be reduced and the yield of a semiconductor element can be improved. Furthermore, the substrate processing apparatus 1 can be realized by modifying existing equipment at a low cost.

  Thus, when the solution is discharged and applied downward from the chemical nozzle 14 disposed on the central axis on the upper surface of the base 2 that can rotate about the central axis extending in the vertical direction, A state in which the base 2 is stationary between a first distance in which the distance L between the nozzle bases from the tip to the upper surface of the base 2 is predetermined and a second distance that is smaller than the predetermined first distance. From time to time, while the base 2 is rotating, the chemical nozzle 14 is moved downward in the vertical direction in conjunction with the rotation of the base 2 while discharging and applying the solution from the chemical nozzle 14 to the upper surface of the base 2. Moving.

  Therefore, if the coating method according to the present invention is applied, the height of the chemical nozzle 14 can be controlled in conjunction with the rotation of the base 2, so that even if a highly viscous solution is applied, the vicinity of the center of the base 2 It is possible to prevent the swell of the solution from coming into contact with the chemical solution nozzle 14 and that the solution is in a candy-like state, that is, a state in which the candy is long and thread-like. The solution can be applied with a film thickness.

  Furthermore, the chemical solution nozzle 14 starts discharging the solution at the first predetermined distance when the base 2 is stationary, and starts discharging the solution. The rotation starts at the same time as the rotation starts, and when the rotation speed of the base plate 2 reaches the predetermined first rotation speed, the base plate 2 drops to the predetermined second distance, and the nozzle base distance L is set to the predetermined second speed. After reaching the distance, the solution discharge is stopped.

  Therefore, since the solution nozzle 14 is raised at the position of the stationary state to discharge the solution, it is possible to prevent the solution nozzle 14 from coming into contact with the swell of the solution near the center, and the base 2 has the first rotational speed. Since the position of the chemical solution nozzle 14 is lowered during the rotation, it is possible to avoid a candy-like state, that is, a state where the candy is long in the form of a thread, and a high-viscosity solution is used as the base 2 Can be applied to the surface of the film with a uniform film thickness.

  Furthermore, since the predetermined first distance is 7 mm to 10 mm, even if the high-viscosity solution is ejected while the base 2 is stationary, the lower distance near the center of the base 2 is higher than that of the low-viscosity solution. However, the chemical nozzle 14 does not come into contact with the highly raised solution.

  Furthermore, since the predetermined second distance is 2 mm to 3 mm, even if the solution is a highly viscous solution, the solution will not be in a candy-like state, that is, the candy will not be in a state in which the tail is long in a string shape. .

  Further, the acceleration time from the stationary state to the predetermined first rotation speed from the stationary state is 0.5 second to 2 seconds, and the predetermined first rotation speed is 500 rotations / second to 2000 rotations. Since rotation / second, the high-viscosity solution starts to spread in a circular shape and does not become a candy-like shape.

  Further, the chemical nozzle 14 discharges the solution for 1 to 5 seconds while the base 2 is stationary, and 2 to 5 when the base 2 is rotating at the predetermined first rotational speed. Since the solution is discharged for 2 seconds, the rising of the highly viscous solution can be controlled, and the solution can be uniformly applied to the substrate when the substrate 2 is rotated.

  Furthermore, since the viscosity of the solution is 250 cp (0.25 Pascal second) or more and 4500 cp or less, the film thickness can be made uniform even when a solution having a high viscosity of 250 cp or more and 4500 cp or less is applied.

  Furthermore, since the solution is a polyimide solution, a polyimide film having a uniform film thickness can be formed.

  Further, since the solution is a solution for forming a photosensitive resin resist film, it is possible to form a photosensitive resin resist film having a uniform thickness.

  Further, the substrate 2 is placed by the substrate suction chuck 11, and the substrate 2 placed on the substrate suction chuck 11 is rotated around the central axis extending in the vertical direction by the substrate rotation motor 13. The chemical solution nozzle 14 disposed on the base plate 2 discharges and applies the solution to the base 2 provided below in the vertical direction, and the nozzle vertical cylinder 15 and the nozzle column 16 move the chemical solution nozzle 14 downward in the vertical direction. The control unit 19 controls the base rotation motor 13 and the chemical solution nozzle 14 so that the solution is supplied to the chemical solution nozzle 14 from when the base 2 is stationary to when the base 2 is rotating. The chemical nozzle 14 is moved from the tip of the chemical nozzle 14 to the base 2 by the nozzle upper and lower cylinders 15 and the nozzle columns 16 in conjunction with the rotation of the base 2 by the base rotating motor 13. Is moved between a predetermined first distance and a predetermined second distance that is smaller than the predetermined first distance.

  Accordingly, the height of the chemical nozzle 14 can be controlled in conjunction with the rotation of the base 2, so that even if a highly viscous solution is applied, the rise of the solution near the center of the base 2 is in contact with the chemical nozzle 14. In addition, it is possible to avoid the state where the solution is in a candy-like state, that is, the state in which the candy is long in the form of a thread, and the solution can be applied to the surface of the substrate 2 with a uniform film thickness.

It is a figure which shows typically the structure of the board | substrate processing apparatus 1 which is one Embodiment of this invention. It is a graph which shows the application | coating sequence in which the board | substrate processing apparatus 1 apply | coats a polyimide solution. It is a figure which shows the film thickness distribution of the polyimide solution formed in the base | substrate 2. FIG. It is a figure which shows the state which discharged the low-viscosity solution and the high-viscosity solution from the nozzle to the base | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base processing apparatus 2 Base 11 Base adsorption chuck 12 Cup 13 Base rotation motor 14, 14a Chemical solution nozzle 15 Nozzle upper and lower cylinders 16 Nozzle support 17 Upper sensor 18 Lower sensor 19 Control part

Claims (10)

An application method for applying a solution by discharging a solution downward in the vertical direction from a nozzle disposed on the central axis on the upper surface of a base that is rotatable about the central axis extending in the vertical direction,
When the base is stationary between the first distance that is predetermined from the tip of the nozzle to the upper surface of the base and the second distance that is smaller than the predetermined first distance. From the time when the base is rotating, the nozzle is moved in the vertical direction in conjunction with the rotation of the base while the solution is discharged from the nozzle onto the top surface of the base and applied. Method. The nozzle is
In a state where the base is stationary and the distance between the nozzle bases starts discharging the solution at the predetermined first distance,
After starting the discharge of the solution, start to descend simultaneously with the start of rotation of the base
When the rotation speed of the base reaches a predetermined first rotation speed, it is lowered to the predetermined second distance,
The coating method according to claim 1, wherein the discharge of the solution is stopped after the distance between the nozzle bases reaches the predetermined second distance.   The coating method according to claim 1 or 2, wherein the predetermined first distance is 7 mm to 10 mm.   The coating method according to claim 1, wherein the predetermined second distance is 2 mm to 3 mm. The acceleration time from the stationary state to the predetermined first rotation speed is 0.5 second to 2 seconds,
5. The coating method according to claim 1, wherein the first rotation speed is 500 rotations / second to 2000 rotations / second.   The nozzle discharges the solution for 1 to 5 seconds while the base is stationary, and discharges the solution for 2 to 5 seconds while the base is rotating at the predetermined first rotation speed. The coating method according to any one of claims 1 to 5, wherein:   The coating method according to any one of claims 1 to 6, wherein the viscosity of the solution is 250 cp (0.25 Pascal second) or more and 4500 cp or less.   The coating method according to claim 1, wherein the solution is a polyimide solution.   The coating method according to claim 1, wherein the solution is a solution for forming a photosensitive resin resist film. Mounting means for mounting the base;
Rotating means for rotating the base placed on the base placing means around a central axis extending in the vertical direction;
Discharging means that is disposed on the central axis and that discharges and applies a solution to the base provided below in the vertical direction;
Moving means for moving the discharge means downward in the vertical direction;
The rotating means and the discharging means are controlled so that the solution is discharged from the discharging means to the upper surface of the base and applied from when the base is stationary to when the base is rotating. Meanwhile, in conjunction with the rotation of the base by the rotating means, the moving means causes the discharge means to be set to a first distance that is predetermined as a distance from the tip of the discharge means to the top surface of the base. And a control means for moving between a predetermined second distance smaller than the distance.

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