JP2003093958A - Method and apparatus for coating substrate with coating liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating method by which the use efficiency of a coating liquid is enhanced. SOLUTION: A liquid reservoir is formed on a substrate W by feeding a coating liquid to the surface of the substrate W held in a horizontal position at the upper surface side of a substrate stage 10. The substrate is held in a fixed direction in plane view. The substrate is moved in the horizontal surface in all directions at a speed such that inertial force acts on the liquid reservoir and within a moving range equivalent to the diameter of the substrate. The coating liquid is successively discharged from the liquid reservoir while following the motion of the substrate, and spread on the entire substrate surface.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor wafer,
Glass substrate for liquid crystal display or photomask,
A substrate such as a substrate for an optical disk is held in a horizontal position, various resists, SOG, SOD, polyimide, and other coating liquids are supplied to the surface of the substrate, and the coating liquid is applied to the entire surface of the substrate. The present invention relates to a coating method for a coating liquid and a coating device.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, for example, when a coating liquid, for example, a resist in the form of a viscous liquid is coated on the surface of a substrate, a spin coating method is often used. In this spin coating method, the resist is supplied to the center of the substrate held horizontally on the substrate stage, the substrate is rotated around the vertical axis in the horizontal plane, and the resist is rotated from the center on the substrate surface by centrifugal force. The resist is spread over the entire surface of the substrate by flowing to the peripheral portion. Then, a resist film having a uniform thickness is formed on the entire surface of the substrate.

[0003]

The above-mentioned spin coating method is an extremely reasonable method from the viewpoint of spreading the viscous liquid supplied to the surface of the substrate so as to have a uniform film thickness on the entire surface of the substrate. Is. However, the spin coating method is by no means an efficient method from the viewpoint of effective use of the coating liquid. That is, according to the spin coating method, it is necessary to continue supplying the coating liquid onto the substrate until the coating liquid supplied to the central portion of the substrate spreads in the peripheral direction by the centrifugal force and covers the entire surface of the substrate with a uniform film thickness. There is. Then, the coating liquid excessively supplied onto the substrate is
Scatters from the periphery of the board to the surroundings. Therefore, there is a problem that the amount of the coating liquid used increases and the utilization efficiency of the coating liquid is extremely low. This problem will become an important consideration in the future when an expensive coating liquid is used, production cost is reduced, waste liquid treatment, etc. are taken into consideration.

The present invention has been made in view of the above circumstances, and provides a method of applying a coating liquid to a substrate, which can dramatically improve the utilization efficiency of the coating liquid, and It is an object of the present invention to provide a coating apparatus that can suitably carry out the method.

[0005]

The invention according to claim 1 is
In a method of applying a coating liquid to a substrate, the coating liquid is supplied to the surface of the substrate held in a horizontal position to apply the coating liquid to the entire surface of the substrate. After forming the puddle, while holding the substrate in a fixed direction in plan view, the substrate is kept in a horizontal plane at a speed at which the inertial force acts on the puddle and within a moving range corresponding to the diameter of the substrate. It is characterized in that it is azimuthally moved, and the coating liquid is sequentially discharged from the liquid pool following the movement of the substrate to spread the coating liquid over the entire surface of the substrate.

According to a second aspect of the present invention, in the coating method according to the first aspect, the coating liquid is applied in an atmosphere of solvent vapor of the coating liquid so that the viscosity of the coating liquid supplied to the surface of the substrate does not change abruptly. Is applied.

According to a third aspect of the present invention, there is provided an apparatus for applying a coating liquid to a substrate, wherein the coating liquid is supplied to the surface of the substrate held in a horizontal position to coat the entire surface of the substrate with the coating liquid.
The substrate is held horizontally on the upper surface side, and the coating liquid is supplied to the substrate stage having the circular hole formed on the lower surface side and the surface of the substrate held on the substrate stage to form a liquid pool on the substrate. Coating liquid supply means, stage support means for supporting the substrate stage in a horizontal posture and in a fixed direction in plan view, and movably supporting it in a horizontal plane, and slidably fitted in the circular hole of the substrate stage. A circular drive plate that fits together, a rotary support shaft that is fixed to the lower surface side of the circular drive plate at a position that is eccentric from the center, and that supports the circular drive plate in a horizontal posture, and that rotates about a vertical axis. The circular drive plate is provided with a rotary motor that makes a circular motion about a rotary spindle.

According to a fourth aspect of the present invention, there is provided an apparatus for applying a coating liquid to a substrate, wherein the coating liquid is supplied to the surface of the substrate held in a horizontal position to coat the entire surface of the substrate with the coating liquid.
A substrate stage that holds the substrate in a horizontal position on the upper surface side, a coating liquid supply unit that supplies the coating liquid to the surface of the substrate held on the substrate stage to form a liquid pool on the substrate,
A stage support means for movably supporting the substrate stage in a horizontal plane while holding the substrate stage in a horizontal posture and in a fixed direction in a plan view; and a linear motor for engaging the substrate stage and moving the substrate stage in the horizontal plane. And a controller for controlling the movement locus and speed of the linear motor.

According to the coating method of the invention of claim 1,
Since the substrate having the surface coated with the coating liquid moves while being held in a fixed direction in a plan view, centrifugal force does not act on the coating liquid on the substrate. Therefore, the coating liquid supplied onto the substrate does not scatter from the peripheral portion of the substrate to the periphery due to the centrifugal force. Further, when the substrate is moved at a certain high speed in a horizontal plane, an inertial force acts on the liquid pool formed on the substrate by supplying the coating liquid to the surface of the substrate so as to stay at that position. On the other hand, as shown in the schematic view seen from the front side in FIG. 5, a part of the coating liquid forming the liquid pool 1 on the substrate W overcomes the inertial force and follows the movement of the substrate W, and Liquid pool on the surface 1
And the thin film-shaped coating liquid 2 gradually spreads around the liquid pool 1. Then, by moving the substrate W omnidirectionally in the horizontal plane, as shown in the plan view of FIG. 6, for example, the coating liquid is supplied to the central portion of the substrate W indicated by the solid line to form the liquid pool 1. In this case, the coating liquid is spread over the entire surface of the substrate W by repeatedly moving the substrate W back and forth, right and left, and further in an oblique direction (not shown) as indicated by the two-dot chain line, respectively. On the other hand, since the substrate only moves within the movement range corresponding to the diameter thereof, for example, referring to FIG. 6, the substrate W is moved forward, backward, leftward and rightward from the reference position shown by the solid line. About the radius of W, and also about the radius of the substrate W from the reference position even in the diagonal direction,
Since only the distance of about the diameter of the substrate W is moved in the front-rear direction, the left-right direction, and the oblique direction, the coating liquid spreading around the liquid pool 1 does not flow down from the peripheral portion of the substrate W.

As described above, in this coating method, the coating area of the coating liquid on the substrate surface is determined by the initial position of the liquid pool formed on the substrate and the moving range of the substrate, and the moving range and moving speed of the substrate By appropriately setting, it becomes possible to limit the coating region to within the substrate surface, and in principle the utilization efficiency of the coating liquid can be made to be almost 100%.

In the coating method according to the second aspect of the present invention, the coating liquid is coated in the atmosphere of the solvent vapor of the coating liquid, so that the viscosity of the coating liquid supplied to the surface of the substrate suddenly increases. Things will not happen. Therefore, it is prevented that the fluidity of the coating liquid supplied to the surface of the substrate is lost and the coating liquid does not spread on the substrate.

In the coating apparatus according to the third aspect of the present invention, the coating liquid is supplied to the surface of the substrate held on the upper surface side of the substrate stage by the coating liquid supply means to form a liquid pool on the substrate. . Then, the rotation motor rotates the rotation support shaft about the vertical axis, and the circular drive plate is moved circularly about the rotation support shaft. The circular drive plate moves circularly in a horizontal plane about a point eccentric from the center, so that the substrate stage in which the circular hole on the lower surface side is slidably fitted to the circular drive plate is horizontally supported by the stage support means. And held in a fixed orientation in plan view,
It is moved in the horizontal plane, and the substrate on the substrate stage also moves in the horizontal plane. With the operation as described above, the coating method of the invention according to claim 1 can be carried out, and the above-described operation is achieved.

In the coating apparatus of the fourth aspect of the present invention, the coating liquid is supplied to the surface of the substrate held on the upper surface side of the substrate stage by the coating liquid supply means to form a liquid pool on the substrate. . Then, the linear motor is driven, and the movement trajectory and speed of the linear motor are controlled by the controller. Then, the substrate stage engaged with the linear motor is moved in the horizontal plane while being held in a horizontal posture by the stage support means in a fixed direction in a plan view, and the substrate on the substrate stage is also moved in the horizontal plane. To do. With the operation as described above, the coating method of the invention according to claim 1 can be carried out, and the above-described operation is achieved.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an example of a schematic structure of a coating apparatus used for carrying out a method of coating a coating liquid on a substrate according to the present invention, and FIG. 1 is a plan view of a main portion. 2 is a vertical cross-sectional view of the main part.

In this coating apparatus, the substrate stage 10 has a rectangular planar shape and holds the substrate W in a horizontal posture on the upper surface side.
Is equipped with. A circular hole 12 having a diameter slightly smaller than the length dimension of one side is formed on the lower surface side of the substrate stage 10. A rectangular support frame housing 14 is arranged outside the substrate stage 10 so as to surround it. One end of a stretchable member 16 such as a tension coil spring is fixed to each of the four ridges of the substrate stage 10, and the other end of each stretchable member 16 is fixed to each corner of the support frame housing 14. The substrate stage 10 and the support frame housing 14 are connected to each other via the four elastic members 16. Then, the substrate stage 10 includes the support frame housing 14
Further, it is supported in a horizontal posture by the elastic member 16 and is supported so as to be movable in a horizontal plane while being held in a fixed direction in a plan view.

A bearing 18 having an outer diameter corresponding to the diameter of the circular hole 12 is attached to the inner peripheral surface of the circular hole 12 of the substrate stage 10. A circular drive plate 20 having a diameter corresponding to the inner diameter of the bearing 18 is fitted on the inner peripheral surface of the bearing 18. Then, the circular drive plate 20
Is the bearing 1 for the circular hole 12 of the substrate stage 10.
It is configured to be slidable via 8.

On the lower surface side of the circular drive plate 20, the upper end of the rotary shaft 24 of the rotary motor 22 is fixed at a position eccentric from the center thereof. The rotary motor 22 includes the support frame housing 14
It is fixed to the housing support member 26 fixed to the inside of the. The circular drive plate 20 is supported in a horizontal posture by the rotary shaft 24, and the rotary shaft 24 of the rotary motor 22 rotates about the vertical axis so that the circular drive plate 20 moves circularly about the rotary shaft 24. It has become a structure.
The rotary shaft 24 of the rotary motor 22 is extended below the rotary motor 22, and a balancer 28 is provided at the lower end of the rotary shaft 24.
Is stuck. The balancer 28 has the same shape as the circular drive plate 20, and is fixed to the rotary shaft 24 so as to be point-symmetrical to the circular drive plate 20 with respect to the center point of the rotary motor 22. When the circular drive plate 20 circularly moves, the balancer 28 symmetrically circularly moves, and vibration of the entire apparatus is suppressed.

In the apparatus having the above structure, the rotary motor 22
By rotating the rotary shaft 24 of the circular drive plate 20.
When (and the balancer 28) circularly moves in the horizontal plane about the rotary shaft 24, the center of the circular motion (axis center of the rotary shaft 24) is eccentric from the center of the circular drive plate 20. The substrate stage 10 engaged with the bearing 18 moves in the horizontal plane. At this time, the substrate stage 10 includes the support frame housing 14 and the elastic member 16.
Since it is supported so as to be held in a fixed direction in a plan view, it moves as shown by a chain double-dashed line in FIG. 3 (the movement locus of the center point O of the substrate stage 10 is shown by a chain line A in FIG. ). Then, the substrate W held on the substrate stage 10 also moves in the horizontal plane as shown by the chain double-dashed line in FIG. The movement range of the substrate W at this time is shown by the one-dot chain line B in FIG. 3, but the movement range of the substrate W is set to a degree corresponding to the diameter of the substrate W, and is not made larger than the diameter of the substrate W. Absent.

Although not shown, the substrate stage 1
Above the substrate W held at 0, for example, a nozzle for supplying a coating liquid, such as a resist, is arranged at a position on an extension line of the center point of the substrate W held in the initial state shown in FIG. The resist supply nozzle has one or a plurality of discharge ports formed on the lower surface side, and the resist supply nozzle is connected to the resist supply unit through a resist supply pipe.

Next, the substrate W is formed by using the above coating apparatus.
An example of the operation of applying the resist to the surface of the will be described.

First, resist is supplied from the resist supply nozzle to the center of the surface of the substrate W held on the upper surface side of the substrate stage 10 to form a resist reservoir on the substrate W. Then, the rotation motor 22 is driven to move the substrate W on the substrate stage 10 in the horizontal plane by the above-described operation. At this time, since the substrate W moves while being held in a fixed direction in a plan view, centrifugal force does not act on the resist on the substrate W, and the resist supplied onto the substrate W is caused by the centrifugal force. It does not scatter from the periphery of W to the surroundings. Further, when the substrate W is moved at an appropriate speed in the horizontal plane, the liquid pool on the substrate W is subjected to an inertial force that tries to stay at that position, but a part of the resist forming the liquid pool is It overcomes the force and moves together with the substrate W in a state of being deposited on the surface of the substrate W in a thin film form, from the position of the liquid pool. As a result, the resist is sequentially drawn from the liquid pool, and the substrate W is covered with the resist in a thin film shape.
Area gradually expands. Finally, the liquid pool is flattened and the resist spreads over the entire surface of the substrate W,
A resist film having a uniform film thickness is formed on the entire surface of the substrate W. During this time, the substrate W only moves within the movement range shown by the alternate long and short dash line B in FIG.

The coating operation described above is preferably performed in an atmosphere of solvent vapor of the resist. In this case, the viscosity of the resist supplied to the surface of the substrate W does not suddenly increase, so that the fluidity of the resist supplied to the surface of the substrate W is lost and the resist on the substrate W is not removed. It is prevented that it does not spread.

Next, FIG. 4 is a schematic vertical cross-sectional view of the essential parts showing another example of the construction of a coating apparatus used for carrying out the coating method according to the present invention. In this coating apparatus, two linear motors 30 are connected back to back to form a drive unit. Reference numeral 32 in the drawing is a drive coil, and the drive coil 32 is fixed to a housing support member 36 fixed to a support frame housing 34. Reference numerals 38 and 40 denote moving elements of the linear motor 30, respectively. The upper moving element 38 has a substrate stage 42 that holds the substrate W on the upper surface side.
And a balancer 44 is attached to the lower moving element 40. The mover 38 on the upper side and the mover 40 on the lower side move in an interlocking manner so as to have a positional relationship of point symmetry with respect to the center point of the drive coil 32. Substrate stage 42
The balancer 44 includes a plurality of elastic members 46,
It is connected to the support frame housing 34 via 48. The substrate stage 42 is supported in a horizontal posture by the support frame housing 34 and the expansion / contraction member 46, and is supported so as to be movable in a horizontal plane while being held in a fixed direction in plan view. The linear motor 30 is designed such that its movement locus and speed are computer-controlled. Although not shown, the substrate W held by the substrate stage 42
A resist supply nozzle is disposed above the.

In the coating apparatus having the structure shown in FIG. 4,
By controlling the movement locus and speed of the linear motor 30 by computer, the substrate W held by the substrate stage 42 can be moved as desired in the horizontal plane, and the same coating device as shown in FIGS. 1 and 2 can be used. The coating operation can be easily performed.

The coating apparatus for carrying out the coating method according to the present invention may have a structure other than that shown in FIGS. For example, according to an apparatus configuration using an XY stage in which a stage that reciprocates in the X direction and a stage that reciprocates in the Y direction are combined,
The same coating operation as above can be performed. Also,
According to the coating method of the present invention, since the coating liquid can be coated only on the effective region of the substrate, it is possible to hold the substrate on the substrate stage using a mechanical chuck that holds the peripheral edge of the substrate. it can. By using such a mechanical chuck, it is possible to avoid that the back surface of the substrate comes into contact with the substrate stage and particles adhere to the back surface of the substrate.

[0027]

According to the method of coating a resist on a substrate of the invention of claim 1, the utilization efficiency of the resist can be dramatically improved.

In the coating method of the second aspect of the invention, it is possible to prevent the fluidity of the coating liquid supplied to the surface of the substrate from disappearing and the coating liquid from spreading on the substrate.

By using the coating apparatus according to the third and fourth aspects of the invention, the coating method according to the first aspect of the invention can be preferably carried out and the above-mentioned effects can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view of essential parts showing an example of a schematic configuration of a coating apparatus used for carrying out a method of coating a coating liquid on a substrate according to the present invention.

FIG. 2 is a longitudinal sectional view of an essential part of the device shown in FIG.

FIG. 3 is a plan view of relevant parts for explaining the operation of the coating apparatus shown in FIGS. 1 and 2.

FIG. 4 is a schematic vertical cross-sectional view of a main part showing another configuration example of a coating apparatus used for carrying out the coating method according to the present invention.

FIG. 5 is a view for explaining the operation of the coating method according to the present invention, which is a schematic view of the substrate as seen from the front side.

FIG. 6 is a schematic view of the substrate as seen from above.

[Explanation of symbols]

W board 10 substrate stage 12 Circular hole on the bottom side of the substrate stage 14, 34 Support frame housing 16,46,48 Elastic member 18 bearings 20 circular drive plate 22 rotary motor 24 Rotational axis of rotary motor 26, 36 Case support member 28,44 Balancer 30 linear motor 32 Linear motor drive coil 38, 40 Linear motor mover

Continued front page    (72) Inventor Mitsunobu Matsunaga             4-chome Tenjin, which runs up to Teranouchi, Horikawa-dori, Kamigyo-ku, Kyoto             1 Kitamachi No. 1 Dai Nippon Screen Manufacturing Co., Ltd.             Inside the company F term (reference) 2H025 AA00 AB16 AB17 EA05                 4D075 AC64 AC66 AC79 AC93 AC94                       BB14Y CA47 DA08 DB13                       DB14 DC22 DC24 DC27 EA07                       EA45 EB39                 4F042 AA07 BA04 BA08 DD02 DD17                 5F046 JA02 JA05 JA09 JA11

Claims (4)

[Claims] 1. A method for applying a coating liquid to a substrate, which comprises supplying the coating liquid to the surface of a substrate held in a horizontal position to apply the coating liquid to the entire surface of the substrate. After forming the liquid pool on the substrate, the substrate is moved in the horizontal plane at a speed at which the inertial force acts on the liquid pool and corresponding to the diameter of the substrate while holding the substrate in a fixed direction in plan view. Within a range, the coating solution is moved in all directions, and the coating solution is sequentially discharged from the liquid pool following the movement of the substrate to spread the coating solution on the entire surface of the substrate. How to apply. 2. The coating on the substrate according to claim 1, wherein the coating is applied in an atmosphere of solvent vapor of the coating so that the viscosity of the coating supplied to the surface of the substrate does not change rapidly. Liquid application method. 3. An apparatus for applying a coating liquid to a substrate, wherein the coating liquid is supplied to the surface of the substrate held in a horizontal posture to apply the coating liquid to the entire surface of the substrate. A substrate stage that holds and has a circular hole formed on the lower surface side, a coating liquid supply unit that supplies a coating liquid to the surface of the substrate held on the substrate stage to form a liquid pool on the substrate, and this substrate Stage supporting means for movably supporting in a horizontal plane while holding the stage in a horizontal posture and in a fixed direction in plan view; and a circular drive plate slidably fitted in the circular hole of the substrate stage, A rotary support shaft that is fixed to the lower surface of the circular drive plate at a position eccentric from the center of the circular drive plate and supports the circular drive plate in a horizontal posture, and the rotary drive shaft is rotated about a vertical axis to rotate the circular drive plate. , Circular movement centering on the rotation spindle A rotation motor for rotating the substrate, and a device for coating a substrate with a coating liquid. 4. An apparatus for applying a coating liquid to a substrate, wherein the coating liquid is supplied to the surface of the substrate held in a horizontal posture to apply the coating liquid to the entire surface of the substrate. A substrate stage for holding, a coating liquid supply means for supplying a coating liquid to the surface of the substrate held on the substrate stage to form a liquid pool on the substrate, and the substrate stage in a horizontal position and constant in plan view. Stage supporting means for movably supporting it in a horizontal plane while holding it in a horizontal direction, a linear motor that engages with the substrate stage and moves the substrate stage in the horizontal plane, and controls the movement locus and speed of this linear motor. An apparatus for applying a coating liquid onto a substrate, comprising: a controller.