JP2003154304A - Method for applying coating material, base material to be coated, method for manufacturing base material to be coated and device for applying coating material including base material to be coated - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for applying a coating material by which an adverse effect due to a monotonous increase in the thickness of a coating film to be generated by a spin- coating process in a base material with a curved surface part, can be reduced and the thickness of the coating film can be prevented from becoming nonuniform so that a difference in the nonuniformity of a coating film thickness between the parts does not become conspicuous, when a coating step is performed a plurality of times, and a base material to be coated, a method for manufacturing a base material to be coated and a device for applying a coating material including a base material to be coated. SOLUTION: The coating material is applied to the base material to be coated with a curved surface part by rotating the base material to be coated to which the coating material is applied. In the rotary coating step, the coating material is continuously made to flow to the top of the curved surface part. Further, this coating material made to flow to the top following the rotation of the base material to be coated at a specified first number of rotation, is applied, while running increasingly smoothly toward the circumferential face part of the periphery of the curved surface part from the top, in almost uniformly maintained thickness of the coating film. In the rotary step, the continuous supply of the coating material is suspended to rotate the base material with the applied coating material at a second larger number of rotations than the first number of rotations.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating material coating method,
TECHNICAL FIELD The present invention relates to a base material to be coated, a method for manufacturing the base material to be coated, and a coating material coating device including the base material to be coated, and in particular, a resist can be coated on a base material having a curved surface to obtain a uniform film thickness distribution. Regarding things.

[0002]

2. Description of the Related Art Conventionally, for example, optical lithography, EB
In (electron beam) lithography, so-called spin coating is known in which a coating material such as a resist is spin-coated on a flat surface of a base material such as a Si substrate.

In this spin coating, resist droplets are dripped near the central portion of a plate-shaped base material, and the base material is rotated so that the resist receives the centrifugal force due to the rotation and the surface of the base material. At the same time as spreading the top, the excess resist will be shaken off. In addition,
The film thickness distribution of the resist on the substrate is determined by the physical properties of the resist (viscosity, surface tension, etc.), the rotation speed of the rotating member (spin coater) when rotating the substrate, and the ambient environment conditions (temperature, etc.).

[0004]

By the way, in the above-mentioned spin coating, when one surface of the substrate to be coated is a flat surface, although a substantially uniform film thickness distribution can be obtained, a curved surface is formed on one surface. When the same spin coating was performed on the substrate having the above, it was not possible to obtain a uniform film thickness distribution. That is, for example, when resist coating is performed on the base material 200 having a curved surface shape as shown in FIG.
There was a region where the film thickness was not uniform.

In addition, when spin coating is performed, a resist solution is dropped to cover the surface of the base material, and then the press pin is performed by rotating the substrate at a predetermined number of revolutions, and then the main coating is performed at a predetermined number of revolutions. A spin will be performed.

However, when spin coating is applied to the curved base material by such a method, the film thickness becomes thin at the top portion, and the film thickness distribution becomes monotonous from the center of rotation of the base material toward the peripheral portion. The increasing tendency became remarkable and the film thickness could not be made uniform.

In particular, due to the special shape of the curved surface, it was not possible to eliminate the change in the film thickness due to the influence of gravity applied to the resist.

Further, in order to obtain a desired film thickness, it is conceivable that the resist coating process and the baking (heating) process are performed plural times. In addition to the nonuniform region of the film thickness caused by the first resist coating, , The non-uniformity of the film thickness caused by the n-th resist coating overlaps, so that the difference in the non-uniformity of the film thickness increases with each repetition.

Further, it is considered that a flat plate portion is formed around the curved surface portion of the base material to improve the flow of droplets by centrifugal force to promote uniform film thickness formation in spin coating. In addition to increasing the size of the base material (base material) and increasing the amount of materials used,
There is a problem that it takes a long time to process the base material and the construction period becomes long.

Further, when the shape of the base material 200 is obtained by cutting with a general-purpose lathe, as shown in FIG.
As shown in (C), a plurality of concentric lines TM called tool marks are formed on the surface of the base material. When the base material fixed to the lathe rotates, the cutting edge of the cutting tool is applied to the rotating base material, and the area where the blade hits occurs on the outer circumference in order to move continuously from the outer circumference for cutting. A concentric tool mark is formed on the surface of the material.

By forming this tool mark, the roughness due to the cutting of the cutting tool is reflected as it is as the "surface roughness of the base material", and for example, the surface roughness in the KD portion of the base material 200 in FIG. Since the surface shape of the base material is in the order of [nm], it is difficult to control the displacement of the film thickness distribution finally obtained by applying the resist to an allowable roughness or less. Here, "surface roughness" means
As shown in FIG. 22B, the roughness curve f (y) is applied to a certain surface.
The measurement length l is extracted from the roughness curve f (y) in the direction of the center line, and the center line of the extracted portion is the X axis, and the direction of the longitudinal magnification is the Y axis.
= F (y) means the value Ra obtained by the formula in the figure. Therefore, if the value Ra, which is the surface roughness, becomes the above-mentioned value, it also affects the film thickness distribution of the resist film.

In particular, since the tool mark is formed, when the film thickness is optically measured, light is diffusely reflected by the groove portion of the tool mark and the film thickness cannot be measured. Was having trouble.

The present invention has been made in view of the above circumstances. A first object of the present invention is to provide an effect due to a monotonous increase in film thickness and an effect due to gravity caused by ordinary spin coating on a substrate having a curved shape. A coating material coating method and a substrate to be coated, which can reduce the unevenness of the unevenness even when the coating process is performed a plurality of times and prevent the unevenness of the unevenness from widening. To provide a material, a method of manufacturing a base material to be coated, and a coating material coating device including the base material to be coated.

A second object of the present invention is to provide a coating material coating method and coating method which can prevent the size of the base material from increasing and can shorten the construction period while favorably performing spin coating. An object of the present invention is to provide a coating substrate, a method for manufacturing a coating substrate, and a coating material coating device including the coating substrate.

Further, a third object of the present invention is that even if a tool mark is formed, it is possible to control the final film thickness distribution to be equal to or less than the allowable roughness, and to perform film thickness measurement and evaluation. An object of the present invention is to provide a coating material coating method, a coating base material, a method for manufacturing a coating base material, and a coating material coating device including the coating base material.

[0016]

In order to achieve the above-mentioned object, the invention as set forth in claim 1 is to rotate the base material to be coated on which the coating material is applied, and to apply the coating material to the base material to be coated. In the coating material coating method for coating, the base material to be coated has a curved surface portion, and the coating material is continuously flowed down to the top of the curved surface portion of the base material to be coated, A spin coating step in which the coating material flowed down to the top by rotating the coating base material at a first rotation speed is coated from the top toward a peripheral surface portion around the curved surface portion, and the coating material. And a rotation step of rotating the substrate to be coated on which the coating material has been applied by the spin coating step at a second rotation speed higher than the first rotation speed. And

The invention described in claim 2 is the same as claim 1.
The coating material coating method as described in [4], wherein in the spin coating step, the base material to be coated is moved at a predetermined acceleration in a rotation axis direction opposite to the film thickness forming surface.

The invention described in claim 3 is the same as that of claim 2.
The coating material coating method described in [4] is characterized in that, in the rotation coating step, the movement at the acceleration is performed until the coating material covers the curved surface portion of the base material to be coated.

In order to achieve the above object, the invention according to claim 4 is to apply a coating material by rotating the substrate to be coated with the coating material to coat the coating material on the substrate to be coated. In the method, the base material to be coated has a curved surface portion, and the top of the curved surface portion of the base material to be coated is faced downward to impregnate a solution tank in which the coating material is immersed to perform coating. And a rotation step of pulling up the substrate to be coated, which is dipped in the coating material, and rotating the substrate at a third number of rotations with the top portion facing downward.

The invention according to claim 5 is the same as claim 4
The coating material coating method according to claim 1, wherein the coating substrate immersed in the coating material is heated at a predetermined temperature after a rotation step of rotating at a predetermined rotation speed while pulling up the coating substrate. A heating step of: and a step of directing the top portion of the base material to be coated on which the first layer of the coating material is formed,
The coating material is continuously flown down to the top of the curved surface portion from above the first layer, and is flowed down to the top as the base material to be coated is rotated at a predetermined first rotation speed. The coating material of the second layer while flowing down smoothly from the top portion to the peripheral surface portion around the curved surface portion while maintaining a substantially uniform film thickness on the first layer And a spin coating step of coating the material.

The invention according to claim 6 is the same as claim 5
The coating material coating method according to claim 1, wherein after the spin coating step, the continuous supply of the coating material is stopped, and the substrate to be coated on which the coating material of the second layer is coated is the first coating material. It further comprises a rotating step of rotating at a second rotation speed higher than the rotation speed of.

The invention according to claim 7 is the same as claim 6
The coating material coating method according to [4], further comprising a heating step of heating the coating target substrate at a predetermined temperature after the rotating step.

The invention according to claim 8 is the same as claim 5
8. The coating material coating method according to claim 7, wherein the coating material having a desired film thickness is formed by repeating the rotation coating step, the rotating step, and the heating step. It is characterized by further including a step of forming a base material.

In order to achieve the above object, an invention according to claim 9 is a coating material coating method for coating a coating material on a coating substrate, wherein the coating substrate has a curved surface portion. A coating process for coating a coating material on the coating substrate, a rotating process for rotating the coating substrate coated with the coating material by the coating process, and a coating process for coating the coating material by the rotating process. A curing step of curing the coated base material thus obtained at a predetermined temperature is repeated to form the coating base material on which the coating material having a desired film thickness is formed.

The invention according to claim 10 is the coating material coating method according to claim 9, wherein the top surface of the curved surface portion of the base material to be coated is faced downward, and the coating material is dipped. A step of applying the coating material onto the coating base material by impregnating a solution tank, and pulling up the coating base material immersed in the coating material in the impregnation step, with the top facing downward. A rotating step of rotating at a third rotation speed, and a heating step of heating the coating target substrate coated with the coating material at the third rotation speed at a predetermined temperature,
With the top of the curved surface portion of the coated substrate facing upward, the coating material is continuously flowed down to the top of the curved surface portion, and the coating substrate is rotated at a first rotation speed. The spin coating step of coating the coating material flowing down to the top from the top toward the peripheral surface around the curved surface portion, and stopping the flow of the coating material, and the spin coating step. In the rotating step of rotating the coated substrate coated with the coating material at a second rotation speed higher than the first rotation speed, the coating material is applied by the rotation of the second rotation speed. The coated substrate,
And a heating step of heating at a predetermined temperature.

The invention according to claim 11 is the coating material coating method according to claim 10, wherein the impregnating step is performed with the top of the substrate to be coated facing downward, and the third rotation speed. Rotating step of rotating at step 1 and performing the heating step 1st
Process, the spin coating process with the top of the substrate to be coated facing upward, the rotation process of rotating at the second rotation speed, and the second process of performing the heating process are alternately repeated. It is characterized by

The invention according to claim 12 is the coating material coating method according to claim 10, wherein the top of the substrate to be coated faces downward, the impregnating step, and the third rotation speed. Rotating step of rotating at step 1 and performing the heating step 1st
After performing the first treatment, the spin coating step with the top of the substrate to be coated facing upward, the rotation step of rotating at the second rotation speed, and the heating step are performed. The second process is performed prior to the second process.

The invention according to claim 13 is the method for applying a coating material according to claim 9, wherein the top of the curved surface portion of the substrate to be coated faces upward, and And the coating material is continuously flowed down, and the base material to be coated is rotated at a first rotation speed, so that the coating material flowed down to the top portion is surrounded by the peripheral surface portion around the curved surface portion from the top portion. A rotation coating step of applying the coating material toward the substrate and stopping the flow of the coating material, and the substrate to which the coating material is applied in the rotation coating step is larger than the first rotation speed. A rotating step of rotating at a second rotation speed, a heating step of heating the coating target material coated with the coating material at the second rotation speed at a predetermined temperature, and the coating target substrate. With the top of the curved surface of the material facing downward, An impregnating step of applying the coating material onto the coated substrate by impregnating a solution bath in which a cloth material is immersed, and pulling up the coated substrate immersed in the coating material in the impregnating step, Third with the top facing down
And a heating step of heating the substrate to be coated on which the coating material has been coated by the rotation of the third rotation number at a predetermined temperature. To do.

The invention according to claim 14 is the coating material coating method according to claim 13, wherein the spin coating step and the second spin coating are performed with the top of the substrate to be coated facing upward. A rotating step of rotating at a number, a second process of performing the heating step, the impregnating step with the top of the substrate to be coated facing downward, and a rotating step of rotating at the third rotational speed, It is characterized in that the first process of performing the heating step is alternately repeated.

The invention according to claim 15 is the coating material coating method according to claim 13, wherein the spin coating step and the second spin coating are performed with the top of the substrate to be coated facing upward. Prior to the second step including the rotating step of rotating by a number and the heating step, the second processing is performed, and the impregnating step and the third step are performed with the top of the coated substrate facing downward. It is characterized in that the first process is performed after the first process of performing the rotating process of rotating at the number of revolutions and the heating process.

According to a sixteenth aspect of the present invention, there is provided the coating material applying method according to any one of the first and fourth aspects, wherein the coating material is applied after the rotating step. A curing step of curing the substrate to be coated is included.

The invention according to claim 17 is the coating material coating method according to any one of claims 1 and 4, wherein the coating material is coated after the rotating step. It is characterized by including a heating step of heating the substrate to be coated at a predetermined temperature.

The invention as set forth in claim 18 is the coating material coating method as set forth in claim 17, wherein the predetermined temperature in the heating step is 100 ° C. to 200 ° C. And

The invention described in claim 19 is the coating material coating method according to any one of claims 1 to 15, wherein the shape of the substrate to be coated is preliminarily formed. It is characterized by including a shape processing step.

The invention as set forth in claim 20 is the coating material application method as set forth in claim 19, wherein in the shape processing step, the peripheral surface portion is formed over the periphery of the curved surface portion. It is characterized in that it is formed so as to include a peripheral flat surface portion and a peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the coating material flows down gently.

The invention according to claim 21 is the coating material coating method according to claim 20, wherein the coating material is applied at a boundary region position between the peripheral surface portion and the curved surface portion in the shape processing step. It is characterized in that a film-thickness correction uneven portion for correcting the film thickness after coating is formed.

Further, the invention according to claim 22 is the coating material coating method according to claim 20, wherein in the shape processing step, the curved surface portion has a center of a top portion to which the coating material flowing down adheres. Therefore, the first radius of the curved surface portion includes the effective curved surface portion up to a predetermined effective diameter required to make the film thickness distribution substantially uniform after coating the coating material, and the curved surface forming the peripheral curved surface portion. Is formed to be 1 to 10 times larger than the second radius, and the boundary area position between the peripheral flat surface portion and the peripheral surface portion where the inclination of the tangent line of the second radius is substantially zero is the effective curved surface portion. It is characterized in that it is formed at a position separated from at least twice the effective diameter of.

The invention according to claim 23 is the coating material applying method according to claim 22, wherein in the shape processing step, a portion from a rotation center of the curved surface portion to a peripheral end of the peripheral curved surface portion is formed. The distance is formed to be 4 times or less the radius of the curved surface portion.

The invention according to a twenty-fourth aspect is the coating material coating method according to the twenty-first aspect, wherein the shape processing step includes a cutting step of cutting the base material to be coated. To do.

The invention as set forth in claim 25 is the coating material coating method as set forth in claim 24, wherein the surface roughness of the curved surface portion is set to 50 nm or less by the cutting process. To do.

The invention as set forth in claim 26 is the coating material applying method as set forth in claim 24, wherein the shape processing step includes a polishing step of polishing the curved surface portion.

The invention as set forth in claim 27 is the coating material coating method as set forth in any one of claims 1 to 26, wherein the viscosity of the coating material is approximately 150 mPa · s or less. It is characterized by

The invention according to claim 28 is the coating material coating method according to any one of claims 1 to 27, wherein the temperature of the coating material is 22 ° C. to 24 ° C. It is characterized by being.

The invention described in Item 29 is the coating material applying method according to any one of Items 1 to 3 and 10 to 15, wherein the second The number of rotations of is about 700 rpm.

The invention described in claim 30 is the coating material coating method according to any one of claims 1 to 3 and 10 to 15, wherein the spin coating is applied. In the process, the first rotation speed is set to 200 rpm to 700.
It is characterized by setting to rpm.

The thirty-first aspect of the invention is the coating material coating method according to any one of the first to third aspects, wherein in the rotating step, the second number of revolutions is set to It is characterized in that the gravity is applied to the coating material on the curved surface portion and the centrifugal force is rotated at a rotational speed at which the centrifugal force is balanced.

The invention described in claim 32 is the coating material coating method according to any one of claims 1 to 3, wherein in the rotating step, the coating material is the curved surface portion. The first balances the gravity and centrifugal force applied to the coating material above.
It is characterized by spin coating as the viscosity of.

A thirty-third aspect of the present invention is the coating material coating method according to any one of the first to thirty-second aspects, in which the base material to be coated is provided on the peripheral surface portion on the peripheral surface portion. A peripheral flat surface portion formed around the curved surface portion, and a peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the coating material flows down smoothly. Is characterized by.

A thirty-fourth aspect of the present invention is the method of applying the coating material according to the thirty-third aspect, wherein the base material to be coated is applied at a boundary region position between the peripheral surface portion and the curved surface portion. The present invention is characterized in that it has a film thickness correcting uneven portion for correcting the film thickness after coating the material.

The invention described in Item 35 is the method for applying the coating material according to Item 33 or Item 34.
The curved surface portion includes an effective curved surface portion up to a predetermined effective diameter required to have a substantially uniform film thickness distribution after coating the coating material, from the center of the top portion to which the coating material flowing down adheres,
The first radius of the curved surface portion is formed to be 1 to 10 times the second radius of the curved surface that forms the peripheral curved surface portion, and the tangent line of the second radius has a substantially zero inclination. The boundary area position between the flat surface portion and the surrounding curved surface portion is formed at a position separated from at least twice the effective diameter of the effective curved surface portion.

A thirty-sixth aspect of the present invention is the coating material application method according to any one of the thirty-third to thirty-fifth aspects, wherein the peripheral edge of the peripheral surface portion is greater than the rotation center of the curved surface portion. Is less than or equal to 4 times the radius of the curved surface portion.

The invention described in Item 37 is the method for applying the coating material according to Item 4, wherein the rotating step comprises:
It is characterized in that the base material coated with the coating material in the coating step is rotated while being pulled up.

The invention described in Item 38 is the method for applying the coating material according to Item 4, wherein the rotating step comprises:
It is characterized in that the base material coated with the coating material in the coating step is pulled up and then rotated.

In order to achieve the above-mentioned object, the invention as set forth in claim 39, the substrate to be coated with the coating material is rotated to apply the coating to the substrate to be coated having at least one curved surface portion. A coating material coating method for coating a material, comprising: forming a curved surface portion having a surface roughness of a first roughness or less on at least one surface of the coating target substrate;
A coating step of flowing the coating material down to the top of the curved surface portion of the coating substrate while rotating the coating substrate.

The invention described in Item 40 is the method for applying the coating material according to Item 39, wherein the first roughness is 20 nm or less.

The invention described in Item 41 is the method for applying the coating material according to Item 39 or Item 40.
The step of forming the substrate to be coated is performed by cutting.

The invention according to claim 42 is the coating material applying method according to claim 41, characterized in that the cutting is performed while temperature control is performed.

The invention described in Item 43 is the method for applying the coating material according to Item 41 or Item 42.
The cutting is characterized by performing shape processing with diamond.

The invention described in Item 44 is the method for applying the coating material according to Item 39, which comprises polishing for polishing the curved surface portion between the step of forming the substrate to be coated and the coating step. In addition to the steps, in the polishing step, the tool mark is polished until the rainbow is no longer visible.

In order to achieve the above-mentioned object, the invention according to a forty-fifth aspect of the present invention is such that a curved surface portion which is formed on at least one surface and on which a coating material is spin-coated, and the coating material is substantially uniform with the spin-coating. A peripheral surface portion formed so as to smoothly flow down from the top of the curved surface portion toward the periphery while maintaining the film thickness, and the distance from the rotation center of the curved surface portion to the peripheral end of the peripheral surface portion, It is characterized in that it is formed to be 4 times or less the radius of the curved surface portion.

In order to achieve the above object, in the invention according to claim 46, the curved surface portion which is formed on at least one surface and on which the coating material is spin-coated, and the coating material is substantially uniform along with the spin coating. A peripheral surface portion formed so as to smoothly flow down from the top of the curved surface portion toward the periphery while maintaining the film thickness, at the boundary region position between the peripheral surface portion and the curved surface portion, after applying the coating material. It is characterized in that an uneven portion for correcting the film thickness is formed to correct the film thickness.

The invention described in Item 47 is the coated substrate according to Item 46, wherein the peripheral surface portion includes a peripheral flat surface portion formed around the curved surface portion, A peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion so that the coating material flows down smoothly, and the film thickness correcting uneven portion includes the peripheral curved surface portion and the curved surface portion. It is characterized in that it is formed at the boundary region position with the part.

Further, the invention according to claim 48 is the base material according to claim 46, wherein the unevenness portion for correcting the film thickness causes the boundary position of the first layer after coating the coating material. It is characterized in that the non-uniform portion formed in the is absorbed.

Further, the invention according to claim 49 is the base material to be coated according to claim 46, wherein when the coating material is applied a plurality of times by the unevenness portion for correcting the film thickness, the coating material is applied. It is characterized in that the non-uniform portion due to all the subsequent layers is absorbed.

According to a fiftieth aspect of the present invention, in the base material to be coated according to the forty-seventh aspect, the curved surface portion is located after the coating material is applied from the center of the top where the flowing coating material adheres. The first radius of the curved surface portion includes an effective curved surface portion up to a predetermined effective diameter that requires the film thickness distribution to be substantially uniform, and the first radius of the curved surface portion of the peripheral curved surface portion is The boundary area position between the peripheral flat surface portion and the peripheral curved surface portion, where the inclination of the tangent line of the second radius is substantially zero, is formed by approximately 1 to 10 times the effective diameter of the effective curved surface portion. It is characterized in that it is formed at a position separated by at least approximately twice.

According to a fifty-first aspect of the present invention, in the coated substrate according to the fifty-fifth aspect, the unevenness portion for correcting the film thickness corresponds to a film thickness distribution characteristic at the boundary region position. It is characterized by absorbing non-uniform portions.

The invention according to claim 52 is the coated substrate according to any one of claims 43 to 45 and 48, wherein the surface roughness of the curved surface portion is ,
The feature is that the thickness is 50 nm or less.

The invention described in Item 53 is the substrate to be coated according to any one of Items 43 to 45 and 48, wherein the surface roughness of the curved surface portion is ,
The feature is that the thickness is 20 nm or less.

The invention according to claim 54 is the base material to be coated according to any one of claims 43 to 53, wherein the base material to be coated is formed of resin. It is characterized by

In order to achieve the above object, the invention as set forth in claim 55, is a curved surface portion formed on at least one surface,
A peripheral flat surface portion formed over the periphery of the curved surface portion, and a coating material continuously flowed down to the top portion of the curved surface portion with rotation,
A peripheral curved surface portion formed at a boundary region position between the peripheral flat surface portion and the curved surface portion for smoothly flowing down from the apex toward the periphery of the curved surface portion while maintaining a substantially uniform film thickness, What is claimed is: 1. A method of manufacturing a coated base material, which comprises manufacturing a coated base material comprising: a film thickness correcting unevenness for correcting a film thickness after coating a coating material at a boundary position between the peripheral flat surface portion and the curved surface portion. A part is formed based on predetermined reference shape data of the unevenness portion for correcting the film thickness, thereby performing processing.

A fifty-sixth aspect of the present invention is the method for producing a base material to be coated according to the fifty-fifth aspect, wherein the reference shape data of the unevenness portion for correcting the film thickness is a plurality of pieces after the coating material is applied. Measuring the film thickness at each radial position of the coating material in the coating substrate, the step of calculating the displacement amount from the reference film thickness, and the average value of the displacement amount of the plurality of coating substrate. And a step of calculating.

The invention described in Item 57 is the method for producing a substrate to be coated according to Item 56, wherein the film thickness at each radial position of the coating material is the same as that after coating the coating material. It is characterized in that it is the film thickness of the first layer.

The invention described in Item 58 is the method for manufacturing a substrate to be coated according to Item 56, wherein the film thickness at each radial position of the coating material is obtained by coating the coating material a plurality of times. In this case, the film thickness of all layers after coating the coating material is characterized.

The invention described in Item 59 is the method for producing a base material to be coated according to any one of Items 56 to 58, wherein the reference film thickness is It is characterized in that the average film thickness of the coating material is within a range of approximately 1.8 mm from the center of the base material to be coated.

In order to achieve the above object, the invention as set forth in claim 60 is such that a holding member for holding and rotating the base material to be coated and a rotation center of the base material to be coated are substantially aligned with each other. A rotation driving means for rotating the holding member; a coating material coating means for coating the coating material; and a control means for controlling the coating amount from the coating material coating means based on the number of rotations by the rotation driving means, It is characterized by including.

The invention according to claim 61 is the coating material coating device according to claim 60, wherein the coating substrate is continuously flowed down onto the coating substrate. A rotation speed for rotating the material at a predetermined first rotation speed, and controlling the substrate to be coated to rotate at a second rotation speed that is higher than the first rotation speed after the coating material is applied. It has a control means, The said control means controls the said 1st, 2nd rotation speed by the said rotation speed control means according to the presence or absence of the supply of the coating material by the said coating material coating means. .

The invention described in Item 62 is the coating material applying apparatus according to Item 61, wherein the rotation speed control means sets the first rotation speed within a range of 200 to 700 rpm. It is characterized by controlling as follows.

The invention according to claim 63 is the coating material coating device according to claim 61, wherein the rotation speed control means applies the second rotation speed to the coating material on the curved surface portion. It is characterized in that it is controlled so as to rotate at a rotational speed at which the gravity applied to the material and the centrifugal force are balanced.

The invention described in Item 64 is the coating material applying device according to Item 63, wherein the rotation speed control means controls the second rotation speed to be near 700 rpm. It is characterized by

According to a sixty-fifth aspect of the present invention, in the coating material coating apparatus according to the sixty-fourth aspect, there is provided a viscosity control means for adjusting and controlling the viscosity of the coating material supplied to the coating material coating means. However, the control means controls the viscosity based on the number of revolutions by the rotation driving means and the coating amount of the coating material.

Further, the invention according to claim 66 is the coating material coating device according to claim 65, wherein the viscosity control means sets the viscosity of the coating material to the coating material on the curved surface portion. It is characterized in that it is controlled so as to have a first viscosity that balances the applied gravity and the centrifugal force.

The invention described in Item 67 is the coating material applying apparatus according to Item 66, wherein the viscosity control means sets the first viscosity to approximately 150 (mPa · S) or less. It is characterized by controlling as follows.

The invention according to claim 68 is the coating material coating device according to claim 60, wherein the coating material feeding time for adjusting and controlling the feeding time of the coating material fed by the coating material coating means. It has a control means, and when applying the coating material, the control means controls the supply time so as to continuously supply the coating material and performs the coating.

The invention described in Item 69 is the coating material applying apparatus according to Item 60, which comprises an elevating means for elevating and lowering the holding member, and an elevating means for rotating the holding member. Gravity control means for controlling lifting and lowering to control the gravity acting on the coating material.

The invention according to claim 70 is the coating material coating device according to claim 60, wherein the holding member is turned upside down and the substrate to be coated is held on the holding member. And a solution tank for immersing the base material to be coated held by the holding member in a coating material, wherein the control means holds the base material to be coated by the fixing means. While being fixed to the member, the solution tank is impregnated by the upside-down inverting means with the top portion of the substrate to be coated facing downward, and thereafter, the substrate is immersed in the coating material with the top portion facing downward. It is characterized in that the coated substrate is controlled so as to be raised while being rotated.

The invention described in Item 71 is the coating material applying apparatus according to Item 60, wherein the holding member is subjected to a centrifugal force generated by the rotation of the substrate to be coated. It is characterized by including a first direction restricting portion for restricting a direction.

A 72nd aspect of the present invention is the coating material coating apparatus according to the 71st aspect, wherein the holding member has a recess for mounting the substrate to be coated, The direction restricting portion is a side wall of the recess.

[0088]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of a preferred embodiment of the present invention will be specifically described with reference to the drawings.

[First Embodiment] (Regarding Overall Structure of Coating Material Coating Apparatus) First, prior to the description of the structure of a substrate to be coated, which is a characteristic structure of the present invention, the term "the present invention" is used. The overall schematic configuration of the resist coating apparatus in which the "coating material coating apparatus" is applied to the "resist coating apparatus" will be described with reference to FIG. FIG. 1 is a functional block diagram showing the overall schematic configuration of the resist coating apparatus of this example.

In the resist coating apparatus 1 (coating material coating apparatus) of the present embodiment, as shown in FIG. 1, a resist coating base material 10 which is a coating base material to which a coating material such as resist is coated is rotated. A spin coater chuck 20, which is a holding member that rotates while holding it around A, and a resist (L shown in FIG. 1), which is a coating material, are placed at a position of a rotation center axis A with respect to the resist coating base material 10. A coating material coating means 31 for coating a resist by continuously flowing down from above,
A viscosity control unit 32 for controlling the viscosity of the resist, a coating amount control unit 33 for adjusting and controlling the amount of the resist coated by the coating material coating unit 31, and a resist for continuously flowing down the resist. A coating material supply time control means 34 for controlling the supply time, a θ direction rotation drive means 35 which is a rotation drive means for rotationally driving the spin coater chuck 20 in the θ direction about the rotation center axis A,
A rotation speed control means 36 for controlling the rotation speed of the spin coater chuck 20 when rotating in the θ direction rotation driving means 35 and, for example, a predetermined resist amount and rotation speed so that the film thickness of the applied resist is substantially uniform. The storage means 37 stores various control condition information such as a correlation table showing a correlation with the above, and further environmental condition, for example, condition information in which a temperature control condition is also added.

Further, the resist coating apparatus 1 includes a Z-direction driving means 41 which is an elevating means for vertically elevating the spin coater chuck 20 in the Z direction which is a vertical direction, and the Z direction driving means 41.
Z direction control means 42 for controlling the drive of the direction drive means 41
Then, the gravity control means 4 controls the movement in the vertical direction so as to remove the influence of gravity when the resist flows down, and gives an instruction to that effect to the Z direction control means 42.
3, and a ψ-direction rotation driving means 44a included in the up-down reversing means 44 for rotationally driving (in other words, vertically inverting) the substrate 10 fixed to the spin coater chuck 20. The spin coater chuck 20 while holding the substrate 10 in each of the XYZ directions.
Of the XYZ-direction moving means 44b (which is included in the up-down reversing means 44), the ψ-direction rotation driving control means 45 for controlling the rotation driving of the ψ-direction rotation driving means 44a, and the XYZ-direction moving means. Even when the spin coater chuck 20 and the XYZ direction movement control means 46 for controlling the movements of the XYZ directions in the respective directions are reversed, the substrate 20.
Base material fixing means 47 for fixing the base material (for example, for fixing the base material 20 by vacuum suction or the like by providing a hole portion).
Based on the base material fixing control means 48 for controlling attachment / detachment of the spin coater chuck 20 to / from the base material 10 by the base material fixing means 47, and various control condition information in the storage means 37, the above-mentioned respective parts application amount control means 36 and a control means 49 for controlling the entire rotation speed control means 32,
The spin coater chuck 20 is turned upside down and lowered to include a dip tank 50 which is a solution bath for impregnating the base material 10 with the solution.

As a matter of course, in the resist coating apparatus 1, in order to control the ambient environment condition, which is one of the control conditions of the resist coating, such as the temperature condition, so that the film thickness becomes substantially uniform during the resist coating. The above-mentioned control means 40
The temperature control means (not shown) linked to the above will be provided. The temperature control condition is, for example, 22 to 2
The setting is preferably controlled at 4 ° C. and 100 to 200 ° C. during baking.

The base material 10 to be coated with resist is formed of a material preferable for forming a lens or the like, for example, a resin member such as polyolefin, and has a curved surface portion 12 having a semicircular cross section to form a curved surface. The peripheral flat surface portion 14 formed over the peripheral region of the curved surface portion 12 and the curved surface portion 12
And a surrounding curved surface portion 16 formed so as to form a smooth curved surface between the surrounding flat surface portion 14. The peripheral flat surface portion 14 and the peripheral curved surface portion 16 of the present example form the “peripheral surface portion” of the present invention.

The spin coater chuck 20 defines the peripheral portion of the resist-coated base material 10 in order to hold the resist-coated base material 10 in rotation, so that the spin coater chuck 20 rotates in the first direction F in which a centrifugal force is generated during rotation. Direction regulation portion for regulating the movement of the resist coating base material, or a recess side wall portion 22 which is a chuck portion for chucking the resist coating base material 10, and a recess bottom wall for holding the bottom surface of the resist coating base material 10 by its own weight. Part 2
4, and is formed to have a substantially concave cross section. That is, the spin coater chuck 20 forms a recess.

In addition to the θ-direction rotation driving means 35 and the Z-direction driving means 41, the spin coater chuck 20 is driven to move in the X-axis and Y-axis directions on the XY plane which constitutes the resist coating surface. After the X-axis direction driving means and the Y-axis direction driving means (not shown) and the spin coater chuck 20 on which the resist coating base material 10 is mounted are conveyed from the predetermined mounting position to the resist coating position, at the resist coating position. Directions for performing the alignment operation of the spin coater chuck 20 (θ direction, Z direction, X direction,
Each adjustment mechanism (not shown) in the Y direction) is included.

The control means 49 controls the viscosity on the basis of the number of rotations by the θ direction rotation driving means 35 and the coating amount of the resist. Further, based on the supply time controlled by the coating material supply time control means 34, the first and second rotations by the rotation speed control means 36 depending on whether the coating material is supplied by the coating material coating means 31. Control the number. further,
After the resist is continuously supplied by the coating material applying means 31, the θ direction rotation driving means 35 rotates the spin coater chuck 20 while controlling the elevation by the Z direction driving means 41, and the gravity control means 43 controls the resist. Control the gravity acting on. Further, while fixing the resist coating base material 10 to the spin coater chuck 20 by the base material fixing means 47, the resist coating base material 1 by the vertical reversing means 44 and the Z direction driving means 41.
0 with the top of the dip tank 50 facing downward
And then with the top facing downwards,
The substrate 10 to be coated with resist, which is dipped in the resist, is controlled to be raised by the Z-direction driving means 42 while rotating.

According to the resist coating apparatus 1 having the above-mentioned structure, the operation is roughly as follows. That is, in the resist coating apparatus 1 of the present embodiment, as will be described in detail in the item “Processing procedure” described later, “The resist is continuously supplied into the press pins, the main spin is performed, and the baking is further performed. "First treatment (second treatment of the present invention) procedure, and" immersing in a solution tank with the top of the curved surface portion facing downward, then pulling up to perform main spinning and further baking " (First processing of the present invention) procedure,
Have.

For this reason, when the resist coating is to be performed in the first processing procedure, first, in the first rotation called "press pin", the θ direction driving means 35 is used. While rotating the spin coater chuck 20 by
The coating material coating means 31 continuously flows down the resist L onto the resist coating base material 10. At this time, various control information is programmed in the storage means 37 so as to perform drive control at the timings shown in FIG. 16, and based on the control information, the control means 49 causes the coating material supply time control means 34 to perform control. Instructing to supply the resist from the coating material coating means 31 during a certain period during the press pin, and the rotation speed control means so that the θ direction rotation drive means 35 rotates at a predetermined first rotation speed (for example, 200 rpm). 36 (instruction is supplied with a control signal), and further, the coating amount control means 33 and the viscosity control means 32 are controlled so as to control the coating amount and viscosity of the resist.

However, the predetermined first rotation speed is smaller than the second rotation speed in the "main spin" described later, depending on the coating amount and the viscosity of the resist L, and the like.
It is preferable that an appropriate value is selected and used within the range of 700 rpm.

Explaining this point in detail, firstly, the reason why the upper limit of the predetermined first rotational speed is 700 rpm is that the purpose of performing press-pinning is that the resist coated substrate 10 will be described later. Spinning is performed at a rotational speed smaller than "spin", and the resist L is continuously flown down on the rotating speed to roughly spread the resist L on the resist-coated base material 10, and as will be described later. As described above, the rotation speed of the "main spin" is approximately 700 rpm (the reason for this will be described later). Further, the lower limit of the predetermined first rotation speed is 200r.
The reason for pm is that, as shown in FIG. 23, the rotational speed in the press pin, that is, the predetermined first rotational speed is 50
rpm, 100 rpm, 200 rpm, 300 rpm,
The final film thickness distribution of the resist L of the resist coating base material 10 when changed to 500 rpm and 700 rpm (the film thickness of the resist L obtained by repeating the step of spin-coating a resist solution described below and the baking step). distribution)
However, under the condition that the predetermined first rotation speed is 100 rpm or less, the result is that the uniformity is poor. Specifically, particularly in the range where the measurement position from the center of the resist-coated substrate 10 exceeds 3 mm, significant nonuniformity in the film thickness distribution is observed as compared with the case of other rotation speeds. At other measurement positions (range of 0 to 3 mm), the film thickness distribution showed non-uniformity as compared with the case of other rotation speeds. The reason for this is that in the former,
It is conceivable that the effect of the centrifugal force is weakened by the decrease in the number of revolutions, the speed at which the resist L spreads around the resist L decreases, and the resist L is dried before spreading over the peripheral portion. In the latter, the influence of the former is considered to be the main one. By the way, the range in which the measurement position from the center of the resist-coated substrate 10 exceeds 3 mm is the range that is actually used, that is, the product equivalent part (actually, the range of about 0 to 2.6 mm). ), And the non-uniformity of the film thickness distribution in this part is
It is likely to be irrelevant to the product, but its influence extends to the actual use range, that is, the product equivalent part (measurement position is 0 to 2.6 mm range). Need to deal with.

Therefore, in the present embodiment, by setting the predetermined first rotation speed to 200 rpm or more, the action of the centrifugal force is secured to a necessary minimum or more, and the resist L is spread to the peripheral portion. In order to prevent the film thickness distribution of the resist L of the substrate 10 to be coated with resist, the number of rotations other than the whole range including the product equivalent part (measurement position is in the range of 0 to 2.6 mm) is prevented. It should be the same (uniform) as (200 rpm or more). In addition, the non-uniformity of the film thickness distribution means that the predetermined first rotation speed is 200 rpm to 700 rpm.
Even within the rpm range, the first rotation speed of the press pin may be 200 rpm depending on the coating amount and viscosity of the resist.
It is preferable that an appropriate value is selected and used from the range of up to 700 rpm.

Next, in the second rotation called “main spin”, the resist solution continuously flown down by the coating material coating means 31 is stopped, and then the θ direction rotation driving means 35 is used. The spin coater chuck 20 is rotated. At this time, the control means 49 instructs the coating material supply time control means 34 to prevent the resist from being supplied for a certain period of time, and at the same time, the second rotation speed higher than the first rotation speed (for example, 700 rpm). The rotation speed control means 36 is instructed to rotate the θ direction rotation drive means 35. The reason why the second rotation speed is set to about 700 rpm will be described later.

In the present embodiment, in addition to the above,
When performing the “main spin”, the Z-direction driving means 41 rotates the spin coater chuck 20 downward while moving it at a predetermined acceleration (for example, 9.8 [m / (s ^ 2)]). At this time, the control means 49 controls the gravity control means 43.
Thus, the Z-direction control means 42 is controlled so as to have an acceleration according to the rotation speed, and the Z-direction driving means 41 is driven at a required acceleration accordingly, thereby moving the spin coater chuck 20. By doing so, it is possible to reduce the influence of gravity when the resist flows down.

On the other hand, when the resist coating is to be performed in the second processing procedure, the resist coating substrate 10 is tipped with the resist coating substrate 10 facing downward by the up-down reversing means 44. Immerse in the solution W in the tank 50. At this time, the base material fixing means 47 fixes the resist application base material 10 and the spin coater chuck 20 so that the resist application base material 10 does not separate from the spin coater chuck 20. Then, the spin coater chuck 20 is rotated by the ψ-direction rotation drive means 44a, and at the same time, XYZ
The spin coater chuck is moved downward toward the tip tank 50 by the direction moving means 44b.

Next, after the resist coating base material 10 is impregnated with the solution W, the spin coater chuck 20 is pulled up by the XYZ direction moving means 44b, and then downwardly oriented by the θ direction rotation driving means 35 to a predetermined position. The “main spin” is performed by rotationally driving at a rotation speed of 3 (for example, 700 rpm). Then, a baking (heating) process is performed at a predetermined temperature. By this treatment, a curing treatment for curing the coating material can be performed.
Other than the baking treatment, it is also possible to use a method such as an ultraviolet curing treatment depending on the coating material. The reason why the third rotation speed is approximately 700 rpm is the same as the reason why the second rotation speed is approximately 700 rpm, and will be described later.

Then, after the resist coating base material 10 is turned upward by the ψ-direction rotation driving means 44a, the coating material applying means 31 rotates the spin coater chuck 20 by the θ-direction driving means 35 while the coating material applying means 31 A “press pin” is carried out, in which the resist L is continuously flowed down to 10. At this time, the control unit 49 instructs the coating material supply time control unit 34 to supply the resist from the coating material coating unit 31 for a certain period during the press pin, and also has a predetermined fourth rotation speed (for example, 200 rpm). At θ
The coating amount control unit 3 instructs the rotation number control unit 36 to rotate (provides a control signal) to rotate the direction rotation driving unit 35, and further controls the resist coating amount and viscosity.
3. Control the viscosity control means 32. Incidentally, the predetermined first
The predetermined fourth rotation speed is an appropriate value within the range of 200 rpm to 700 rpm, which is smaller than the fifth rotation speed to be described later, depending on the coating amount of the resist and the viscosity. Selected and used.

Further, the "main spin" is performed by stopping the resist solution continuously flown down by the coating material coating means 31 and rotating the spin coater chuck 20 by the θ direction rotation driving means 35. At this time, the control means 49 instructs the coating material supply time control means 34 to control so that the resist is not supplied for a certain period of time, and at the same time, the fourth means.
5th rotation speed that is higher than the rotation speed of
At m), the rotation speed control means 36 is instructed to rotate the θ direction rotation drive means 35. The reason why the fifth rotation speed is approximately 700 rpm is the same as the reason why the second rotation speed is approximately 700 rpm, and will be described later.

(Structure of Resist Coated Substrate) Next, the specific structure of the resist coated substrate 10 to which the resist solution is coated will be described with reference to FIGS.

The resist-coated base material 10 of the present embodiment
In the above, the resist is spin-coated after the surface treatment for giving affinity to the resist, and forms the curved surface portion 12, the peripheral flat surface portion 14, and the peripheral curved surface portion 16 as described above.

Specifically, as shown in FIG. 3, a region extending from a top X1 (top of the resist-coated base material 10) of a curved surface to a surface X2 is defined as a curved surface portion 12, while the resist-coated base material 10 is formed. The peripheral area formed around the curved surface portion 12, which is a spherical surface extending from the peripheral edge X4 to X3, is defined as a peripheral flat surface portion 14, and a boundary area between the peripheral flat surface portion 14 and the curved surface portion 12 between X2 and X3 is defined. The surrounding curved surface portion 16 is used. As a result, the resist smoothly flows down from the curved surface portion 12 toward the peripheral flat surface portion 14 via the peripheral curved surface portion 16,
The resist is applied to the curved surface portion 16, the peripheral curved surface portion 16 and the peripheral flat surface portion 14.

The curved surface portion 12 is, as shown in FIG.
A predetermined effective diameter r1 required to make the film thickness distribution substantially uniform after the resist is applied from the center of the top where the flowing resist adheres (in FIG. Only the region is shown, and the "diameter" in this example means the radius, but in the case of a spherical surface,
Conceptually, it is the diameter when the radius is doubled, so there is no difference even if the term "diameter" is replaced to mean the diameter). The curved surface part 1
2 is not limited to the spherical surface as shown in FIG. 2B, but may be any other curved surface that is an aspherical surface.

By constructing the peripheral flat surface portion 14, the resist solution can be blown to the periphery by the centrifugal force, and the resist liquid can flow down while maintaining the film thickness uniformity.

Further, as shown in FIG. 2A, the peripheral flat surface portion 14 has a position recognizing portion 15 for recognizing the position of the resist coated base material 10 itself. This position recognition unit 1
A plurality of, for example, three 5 are formed, and in this example, as shown in FIG. 2B, a convex portion having a convex cross section is formed. Thus, even if the surface of the peripheral flat surface portion 14 is covered with the resist, the convex position recognition portion 15 can perform position recognition such as exposure in the next step.

More specifically, by preventing the resist from spreading on the position recognizing section 15 of the peripheral flat surface section 14, the recognition accuracy of the position recognizing section 15 is improved, and the exposure apparatus in the next step, EB ( It is possible to improve the positioning accuracy in the electron beam drawing apparatus. The position recognizing portion 15 is preferably arranged at a position r3 separated from the effective curved surface portion 12a by at least approximately three times the effective diameter r1. This is because it does not interfere with the surrounding curved surface portion 16. Furthermore, in the above-mentioned example, the position recognition unit 15 is formed by the convex portion having a convex shape, but the present invention is not limited to this.
It may be a concave portion having a concave cross section, or may be formed by a position recognition mark. Even with such a configuration, the same operational effect as described above can be obtained.

In the peripheral curved surface portion 16, as shown in FIG. 2 (B), the first radius R1 of the curved surface portion 12 is approximately 1 to almost the same as the second radius R2 of the curved surface constituting the peripheral curved surface portion 16. It is preferable to configure so as to be formed by 10 times. Further, the boundary area position X3 between the peripheral flat surface portion 14 and the peripheral curved surface portion 16 where the inclination of the tangent line of the second radius R2 becomes substantially zero.
Is at least approximately 2 of the effective diameter r1 of the effective curved surface portion 12a.
It is preferable to form it at a position r2 which is more than double the distance. This is because it is possible to promote the smooth flow-down of the resist by the peripheral curved surface portion 16 and obtain a uniform film thickness on the curved surface portion 12a within the effective diameter r1.

This point will be described in detail. For example, FIG.
As shown in, the effective diameter (r1 in FIG. 2B) and
Distance to the point where the tangent slope becomes almost 0 (Fig. 2 (B))
The relationship with r2 in is the curved surface of the first radius R1 = 4 mm, and in obtaining the effective diameter r1 = 2 mm, the point where the inclination of the tangent line of the second radius R2 becomes almost 0 is the rotation center of the base material 10. Therefore, it was found that when r2 = 4 mm, a substantially uniform film thickness could be obtained from the rotation center of the base material 10 to about 2 mm. This provides the reason why it is preferable to form the boundary region position X3 between the peripheral flat surface portion 14 and the peripheral curved surface portion 16 at the position r2 which is separated from the effective diameter r1 by at least approximately twice.

In this example, the surrounding curved surface portion 16
Although the example of forming a spherical surface is shown, the present invention is not limited to this, and may be formed of any curved surface which is an aspherical surface. Alternatively, the peripheral curved surface portion 16 may be formed of a combination of a curved surface and a flat surface (taper) or a flat surface as long as the uniform thickness of the resist film can be obtained.

At the boundary X2 between the peripheral flat surface portion 14 and the peripheral curved surface portion 16, the unevenness portion 13 for film thickness correction is formed, and it becomes possible to absorb the uneven film thickness portion in this region at a predetermined rotation speed. (Details will be described later).

Further, in this example, it is preferable that the resist as the coating material has a composition in which the amount of evaporation is small at a predetermined rotation speed. As this composition, for example, it is preferable to perform spin coating using a resist having a viscosity (at least) lower than 150 (mPa · S). As a result, as shown in FIG. 1, when the resist L starts to rotate while flowing down, the resist L spreads in the peripheral region along the direction of the arrow T so that the film thickness becomes uniform due to the centrifugal force and the gravity applied to the resist L. Because.

By storing a correlation table showing the relationship between the number of revolutions and the film thickness at each viscosity in the storage means 38 of FIG. 1 or the like, the viscosity control means 37 causes the rotation according to the desired viscosity of the resist. It is more preferable to have a configuration in which the number can be controlled.

Further, by forming the peripheral curved surface portion 16, the gentle curved surface between the curved surface portion 12 and the flat portion 14 spreads the resist L while flowing down smoothly. Can be made uniform. Further, by forming the peripheral flat surface portion 14 in the peripheral region of the curved surface portion 12, as shown in FIG. 2A, the outer periphery of the peripheral flat surface portion 14, that is, the top portion X1 of the curved surface portion.
Since the resist L is scattered from a position at a uniform height from
Uniform force on the resist film in the outer peripheral direction (resist viscosity,
A combination of centrifugal force and gravity when descending) is applied to control the film thickness.

Furthermore, by forming the material of the resist-coated base material 10 with, for example, a resin member, the resist-coated base material 10 can be easily processed by injection molding, cutting or the like, and can be easily supplied. it can. That is, as a result of intensive studies by the present inventors, the resist-coated base material 1 is applied to the resist used for the electron beam and the solvent used for the developing solution.
When 0 was formed from a resin such as polyolefin, it was found that there was little change due to the solvent. further,
It is preferable that the resist-coated base material 10 is formed of a first conductivity type impurity member such as n-type silicon. This is because it is easy to apply optical film thickness evaluation after resist application.

(Characteristics of this Embodiment) Here, the resist-coated base material 10 having the above-described structure generally operates as follows. In the present embodiment,
"Set r4 to be less than 4 times the radius of the curved surface portion", "Prepare the unevenness portion for film thickness correction in advance on the substrate side", "Set the number of rotations and the viscosity to a predetermined range", "Set the resist Since it is characterized by "continuous supply at press pin", "correction by gravity control", "correction by dipping in a dip tank and spin coating", "surface roughness", etc. Will be described in detail for each item.

(Less than 4 times the radius of the curved surface portion) First, the first feature of the present embodiment is that the distance r4 from the rotation center of the curved surface portion 12 to the peripheral edge of the peripheral flat surface portion 14 is The point is that the radius is less than or equal to four times R1.

For example, as shown in FIG. 11 (A), R1
= 4 mm and R2 = 4 mm, the bending point X2 which is the boundary region between the curved surface portion 12 and the surrounding curved surface portion 16 is 3 m from the center of rotation.
It was found that when the distance was m, the film thickness was uniform when the distance r4 to the peripheral edge was 11 mm. Therefore, it is preferable that r4 is slightly smaller than approximately four times R1, and conversely, r4 will only increase in size even if it has a length four times or more than R1, and the longer it will be. The effect of making the film thickness uniform is not so obtained.

Therefore, by setting the size of the resist-coated base material 10 to the minimum size required for uniform film thickness, the base material size in the manufacturing stage can be reduced. Therefore, the processing of the base material does not take time, the construction period can be shortened, and the throughput is improved. In addition, cost reduction can be achieved by reducing the amount of members used.

For example, as shown in FIG. 6, when obtaining an effective diameter r1 = 2 mm on a curved surface with a first radius R1 = 4 mm, a point X3 at which the inclination of the tangent line of the second radius R2 becomes almost 0 is set. It has been found that when r2 = 4 mm from the rotation center of the base material 10, a substantially uniform film thickness can be obtained from the rotation center of the base material 10 to about 2 mm. No, r
When 2 (X3) = 3, r2 (X
When 3) = 4, the film thickness becomes more uniform in (10A).

That is, when r2 (X3) = 4 (10
In A), a nonuniform film thickness occurs near the bending point X2, but the film thickness is almost uniform in other regions. However,
Regarding the non-uniform portion, a shape (dotted line portion) that eliminates (absorbs) the non-uniform portion is formed in advance in the resist-coated substrate 1
It is preferable to form the unevenness portion 13 (offset correction) for correcting the film thickness by making it in the region of the bending point X2 of 0 (boundary between the curved surface portion 12 and the peripheral curved surface portion 16). Thereby, even if the non-uniform portion is formed, the outer shape of the “resist-coated substrate + resist” can be accommodated in a predetermined shape.

(Regarding the Shape of X2) Next, the more detailed structure of the “film thickness correction uneven portion 13” will be described. First, FIG. 7 discloses the relationship between the rotation speed and the distance from the rotation center of the substrate in each layer and the thickness of the resist when the resist is continuously supplied.

For example, assuming that the desired film thickness of the final resist is approximately 1600 nm, in the example shown in the figure, resist coating and baking are each performed twice, and the resist is applied twice.
It is assumed that the final film thickness is obtained by using the layer structure. In this case, when the rotation speed is 700 rpm, the first layer has a resist thickness of about 700 nm, and the second layer has a resist thickness of about 900 nm, resulting in a final thickness. Is approximately 1600 nm
It is around.

By the way, in the first layer at 700 rpm,
Up to a distance of 2 mm from the center, the film has a substantially constant film thickness, but in the region near the bending point X2, a nonuniform portion M1 in which the film thickness is slightly nonuniform is formed. In addition, 7
Also in the second layer of 00 rpm, the bending point X2
In the vicinity region, a non-uniform portion M2 having a slightly non-uniform film thickness is formed. The non-uniform portion M2 is the non-uniform portion M
It is considered that the influence of the thickness of the nonuniform portion due to No. 1 is included.

Therefore, in the present embodiment, in order to absorb the thickness of the nonuniform portion M1, the unevenness portion 13 for film thickness correction is formed in advance in the region near the bending point X2 of the resist coating base material 10. There is. That is, the unevenness portion 13 for film thickness correction is formed so as to be recessed in a portion where the uneven portion M1 rises and has a large thickness, and the unevenness portion M1 is formed in a portion where the thickness is small. By making the correction concave-convex portion 13 convex, the thickness of the “resist-coated substrate 10 + resist” can be made uniform.

Here, a method of determining the shape of the unevenness portion 13 for correcting the film thickness will be described. As described above, the film thickness is almost constant within a range of about 2 mm from the center of the resist coating base material 10. Therefore, in this example, 1. 8m
The range up to the distance of m is defined as a flat film thickness portion, and the average value of the resist film thickness in this flat film thickness portion is referred to as a reference value. As shown in FIG. 24, first, the resist film thickness is measured at each radial position of a plurality of, for example, 32 resist-coated base materials 10 on which the resist is applied in all layers. Then, the amount of displacement of the resist film thickness at each radial position from the reference value is calculated. Furthermore, FIG.
As shown in, the average value of the displacement amounts (32 average values in this example) is obtained, and based on this, the reference shape data of the unevenness portion 13 for correcting the film thickness, that is, the baseline is created. Then, after that, when the unevenness portion 13 for correcting the film thickness is formed on the resist-coated base material 10, the shape processing is performed based on this baseline. More specifically, in the step of processing the substrate 10 to be coated with resist, which will be described later, when performing diamond cutting with an ultra-precision lathe to cut the substrate 10 to be coated with resist, the feed amount and the cutting amount Is determined on the basis of this baseline to form the film thickness correcting uneven portion 13.

Here, FIG. 26 shows the plurality (arbitrary 20) of resist-coated substrates 10 from the baseline.
The amount of displacement of the resist film thickness at each radial position is shown. In the same figure, a range in which the radial position corresponding to the product is from 0 to 2.6 mm is extracted and the film thickness displacement amount is shown. In this example, 3 out of 20 individuals were out of the control value ± 14 [nm] /0.2 [mm]. However, the remaining 17 pieces are within the control value, and as a result, the non-defective rate is 17 pieces / 2.
The result is 0 pieces = 85%.

By the way, the control value here is defined as follows. "Base material 10 to be coated with resist
If an error occurs between the actual shape composed of + resist and the designed shape (ideal shape), when the resist-coated base material 10 is manufactured as an optical lens, for example, a wavefront aberration such as a spherical aberration is generated. Deterioration occurs. This wavefront aberration ΔW is preferably ¼ or less of the wavelength λ of the incident light, as known as the Rayleigh limit, and is expressed in the following formula. ΔW = (n−1) d ≦ λ / 4 Here, for example, when the wavelength λ of the incident light is λ = 400 nm and the refractive index n is n = 1.5, the allowable shape error d
Is d ≦ λ / 4 (n−1) = 400 [nm] / 4 (1.5−1) = 200 [nm]. However, in reality, other error factors must also be considered, so the allowable shape error d must be determined in consideration of the safety factor. In particular, as in the case of the present embodiment, when the mold shape is manufactured through multiple steps including the transfer step (see later), all the margins are used up by only one step. Therefore, the error control value of the film thickness distribution shape is ± 35 [nm] /0.5 [mm] (= ± 14 [n
m] /0.2 [mm]).

Regarding the method of measuring the resist film thickness at each radial position of the substrate 10 to be coated with resist, Japanese Patent Application No. 2002-0081162, which is a prior application of the present inventor.
However, the basic principle thereof will be briefly described as follows. As shown in FIG. 27,
When the substrate L coated with the film M is irradiated with the light L1 (such as halogen light having a relatively wide visible band), the reflected light is reflected light L2 reflected on the surface of the film M.
And the reflected light L3 reflected by the surface of the substrate B. Here, if the film thickness of the film M is d and the refractive index thereof is n, the optical path difference of the reflected light L3 is longer than that of the reflected light L2 by about 2d, so that light interference occurs and the film thickness d is changed. Accordingly, a peak of light intensity occurs at a predetermined length. Therefore,
A reflected light spectrum can be obtained by converting the reflected light into an electric signal by a solid-state image sensor or the like and analyzing the electric signal. Here, when the light source wavelength is, for example, i-line or g-line,
Since it has a wide wavelength band to some extent, the peak of light intensity becomes unclear. Therefore, by irradiating the substrate B, which is not coated with the film M in advance, with light from a light source, the reflectance spectrum thereof is similarly obtained, and based on the difference between the reflectance spectra before and after the coating of the film M, A graph as shown in FIG. 28 can be obtained. FIG. 28 shows a spectrum (reflectance spectrum) analysis of reflected light in the state shown in FIG. 27, which has a peak of a peak at 582 nm.
There are valley peaks at 48 nm and 622 nm. Here, the peak wavelength of the peak is λ _{2 m,} and the peak wavelength of the valley is λ _{2.
2m + 1} , the film thickness d of the film M and the refractive index n are nd =
It can be represented by (λ _2m × λ _{2m + 1} ) / 4 (λ _2m −λ _{2m + 1} ). Therefore, if the refractive index n is known, the film thickness d can be calculated. However, it should be noted here that, in the present embodiment, since the resist-coated base material 10 that is an object to be measured has a curved surface shape, in order to accurately measure the film thickness d of the resist L, In each case, the incident angle of the light L1 is set to approximately 90 degrees with respect to the measurement target curved surface of the resist coating base material 10, that is, the traveling direction of the light L1 and the measurement target curved surface of the resist coating base material 10 are substantially orthogonal to each other. Measurement is required. The apparatus and method for realizing this are described in detail in Japanese Patent Application No. 2002-0081162.

As described above, the unevenness portion 13 for correcting the film thickness is formed in advance in the region near the bending point X2 of the substrate 10 to be coated with resist.
Since the film thickness can be made uniform in the second layer, the height difference of the non-uniform portion generated in the second and subsequent layers can be minimized (within the allowable range) and the film thickness can be made substantially uniform.

In the above example, the unevenness portion 1 for film thickness correction is used.
Although the shape that absorbs the nonuniform portion M1 due to the characteristic of the first layer at 700 rpm is illustrated as 3, the shape may absorb the nonuniform portion M2 due to the characteristic of the second layer at 700 rpm. Furthermore, the case where the resist film is formed in two layers has been illustrated, but the present invention is not limited to this, and the case where only one layer is formed or a case where two or more layers are formed may be used.

At this time, the nonuniform portion M due to the characteristics of the nth layer
Depending on the characteristic shape of n, if the unevenness portion 13 for correcting the film thickness is formed to be able to absorb the characteristic shape, all the influences of the non-uniform portions of each layer due to the multilayer formation are removed, and finally a substantially uniform shape is obtained. It is more preferable because the film thickness can be reliably obtained.

On the other hand, although the case of 700 rpm has been described, the shape of the unevenness portion 13 for correcting the film thickness may be formed in accordance with the characteristics of another specific rotation speed. At this time, for example, at 2000 rpm, a noticeable non-uniform portion is seen in the second layer, so it is preferable to make the shape corresponding to the non-uniform portion in the second layer. Also, 4
At 000 rpm, no non-uniform portion can be seen in the first layer.
Need not be formed, and these may be appropriately changed depending on the number of rotations.

Since the shape of the non-uniform portion has some reproducibility according to each rotation speed, the film is formed with reference to the shape of the average of the shapes of the non-uniform portions at the characteristics of each rotation speed. You may set the shape of the unevenness part 13 for thickness correction.

As described above, the surface of the final resist film can be made uniform by forming the unevenness portion 13 for correcting the film thickness on the resist-coated substrate 10 in advance.

(Regarding Viscosity and Rotational Speed) Next, the setting range of viscosity and rotational speed will be described. Here, before explaining the relationship between the rotational speed or the viscosity and the film thickness,
A general spin coating mechanism will be described.

First, when the substrate 10 to be coated with resist has a flat plate shape, a solution (resist solution) by centrifugal force is applied.
The relational expression expressing the spread of the in the outer peripheral direction is as shown in S11 of FIG. As a result, the resist coating amount (flow rate) q
Is as in S12 of FIG. 9, and the resist film thickness per unit time is as in S12 of FIG. Here, in each of these equations, as shown in FIG. 8A, the rotational angular velocity ω of spin coating (during spin coating), the resist thickness h, the resist portion radius r, the resist viscosity η, and the minute thickness. z, resist coating amount q, and evaporation rate e.

On the other hand, when the substrate 10 to be coated with resist has a curved shape, a solution (resist liquid) by centrifugal force is applied.
The relational expression expressing the spread of the
become that way. As a result, the resist coating amount (flow rate) q
Becomes like S22 in FIG. Here, FIG. 8 (B)
As shown in, the radial angle Θ is set on the curved surface.

Thus, for example, the relationship between the film thickness h at a predetermined position on the curved surface at a specific viscosity η and angular velocity ω can be theoretically set by S22 shown in FIG. However, this applies only to the curved surface portion of the present embodiment, and does not include the influence on the peripheral curved surface portion and the peripheral flat surface portion.

Under the above-mentioned premise, the resist coating base material having the curved surface portion, the peripheral curved surface portion, and the peripheral flat surface portion as in the present embodiment is rotated so that the film thickness becomes uniform. Consider the number and inflection point X2 position.

For example, as shown in FIG. 11 (A), R1
= 4 mm and R2 = 4 mm, the bending point X2 which is the boundary region between the curved surface portion 12 and the surrounding curved surface portion 16 is 3 m from the center of rotation.
When m is set, the relationship between the gravity applied to the resist solution on the curved surface portion 12 and the centrifugal force is as shown in FIG. 11B, when the rotation speed is 700 rpm, the centrifugal force A1 and the gravity A2 are Balanced on the bending point X2, but the rotation speed is 800r
In the case of pm (FIG. 11C), centrifugal force A1 and gravity A
The position where 2 is balanced is the radial position on the rotation center axis side with respect to the bending point X2, and conversely, when the rotation speed is 600 rpm (FIG. 11D), the position where the centrifugal force A1 and the gravity A2 are balanced. Is a radial position on the outer peripheral side of the bending point X2.

When the rotation speed is around 700 rpm, centrifugal force and gravity tend to be balanced near the bending point X2, but when the rotation speed increases to 1000 rpm and 2000 rpm, the term of rω ^ 2 becomes large and the centrifugal force increases. The power becomes bigger,
Since the centrifugal force becomes larger than the gravity at a position closer to the central axis of rotation, the centrifugal force, the gravity and the bending point X2 are not balanced.

Therefore, in the setting example shown in FIG. 11 (A), since the position is balanced at the bending point X2, it is preferable that the number of revolutions is about 700 rpm.

In this way, the film thickness can be controlled by changing the viscosity of the resist solution by selecting the position of the bending point X2 and the number of rotations.

Here, even if the above conditions are satisfied, a film thickness non-uniform portion occurs in the region near the bending point X2 as shown in FIG. 7 described above. It can be solved by the correction uneven portion.

In this case, what is important is that the film thickness non-uniformity is generated in such a bending point X2 region, but in the region other than the bending point X2, the film thickness is made uniform at the rotational speed of about 700 rpm. It was in the point that was able to achieve. Therefore, it is possible to make the film thickness uniform by combining such selection of the number of rotations and the film thickness correcting uneven portion.

Next, as a comparative example, it is assumed that a resist is applied in a manner similar to continuous downflow. For example, in FIG.
As shown in (A), the rotation speed is 700 rpm, and the viscosity is a viscosity at which the evaporation amount is not remarkable at the rotation speed, for example, 66 to 276.
When the cp is set, the change with time of the film thickness during the time of 0 to 135 seconds becomes H0 to H12 in the figure, but with the passage of time,
The film thickness becomes uniform. As a matter of course, since the resist solution flows, the film thickness becomes flat in a certain time.

On the other hand, as shown in FIG. 12 (B), the time is 0 when the rotation speed is 2000 rpm and the viscosity is a viscosity at which the evaporation amount is not remarkable at the rotation speed, for example, 100 to 400 cp.
The time-dependent change of the film thickness during ˜9 seconds is H0 to H12 in the figure, but in any case, a nonuniform film thickness portion is generated in the region near the bending point.

As a result, the rotation speed becomes particularly large 2000
It is apparent that the rpm is not preferable, and it is inevitable that the rotation number is about 700 rpm from the viewpoint of uniform film thickness.

The viscosity is 66 cp to 276 cp.
It is preferably about 150 mPa, but further 150 (mPa
-S) It is preferable that it is the following.

As described above, the viscosity is almost 1 so that the gravity applied to the curved resist and the centrifugal force can be balanced.
A resist solution of 50 [mPa · S] or less is almost 700
By repeating the process of spin coating at [rpm] and the baking process, a substantially uniform desired film thickness can be obtained.

(Regarding Advantages of Continuous Supply) For example,
As a comparative example, as shown in FIG. 20 (A), after a resist solution is dropped in a period T0 to cover the surface of the resist-coated substrate, a predetermined number of revolutions (eg, 200 rpm) in a period T2.
It is assumed that a spin coating method is performed in which the press spinning is performed by rotating at, and then the main spinning is performed at a predetermined rotation speed (for example, 1500 rpm to 400 rpm) in the period T4. In this case, the rotation speed is 7 as shown in FIGS.
Viscosity is 100 cp at 00 rpm, rotation speed is 2000 rp
The viscosity is 100 cp at m, the rotation speed is 4000 rpm, the viscosity is 100 cp, the rotation speed is 2000 rpm, the viscosity is 300 cp.
In any case of cp, rotation speed of 4000 rpm and viscosity of 300 cp, the tendency that the film thickness monotonously increases on the rotation center axis side from the bending point is remarkable.

On the other hand, in this embodiment, the resist liquid is continuously supplied into the press pins. Specifically, for example, as shown in FIG. 16, first, a period T1 (for example, 2s
ec), the rotation speed is increased and the period T2 (for example, 5se
During c), the resist liquid L is continuously supplied into the press pin that rotates the resist-coated substrate 10 at the first rotation speed (for example, 200 rpm) to constantly replenish it.

As a result, with respect to the film thickness which tends to become thinner in the top region of the curved surface portion 12 due to gravity and centrifugal force, the speed at which the film thickness is about to be reduced (the force cannot be retained at the top portion). By continuously supplying the resist solution as described above, the amount of the resist solution that is about to be thinned is replenished, and a uniform film thickness can be obtained on the curved surface portion 12.

After that, the supply of the resist solution is stopped,
The rotation speed is increased during the period T3 (for example, 2 sec), and the main spin is performed during the period T4 (for example, 600 sec).
The spin coating is completed at 5 (for example, 2 sec).

When the resist solution L is continuously supplied, a syringe or the like constituting the coating material coating means 31
It can be realized by starting using the pneumatic pressure at the same time as the trigger from the coating material supply time control means 34 and controlling the pneumatic pressure of the dispenser or the like according to the number of revolutions. In addition, it is preferable that the coating material coating unit 31 is configured with a pulsation preventing unit that reduces the influence of pulsation during continuous supply.

As described above, by continuously supplying the resist solution into the press pins with respect to the rotation center axis of the substrate to be coated with resist, it is possible to compensate for the decrease in the resist solution at the rotation center portion due to rotation. The film thickness distribution did not increase monotonically from the center of rotation to the periphery of the resist-coated substrate.

(Correction by Gravity Control) In the present embodiment, the resist coating base material 10 is mounted in the main spin or press pin by the gravity control means 43 as shown in FIG. By moving the spin coater chuck 20 downward in the vertical direction (Z1 direction) at a predetermined acceleration, the influence of gravity applied to the resist solution on the curved surface portion 12 is reduced.

At the time of rotation, a downward force is applied to the resist solution on the curved surface portion 12, so that only in the section to be rotated,
By moving downward by the gravity control means 43, an upward force that cancels the downward force is generated, and as a result, it is possible to eliminate the influence of gravity applied to the resist solution during rotation. In particular, the resist solution L is
The effect becomes remarkable when the downward operation is performed only during the period when it reaches the slope of No. 2.

As described above, by moving downward in the vertical direction during rotation, it is possible to reduce the influence of gravity applied to the resist solution on the curved surface portion, and it is possible to contribute to making the resist film thickness distribution uniform. .

(Correction by immersing in dip bath) Next, referring to FIG.
Another method for eliminating the nonuniform thickness portion shown in FIG.

More specifically, as shown in FIG. 19, the base material 10 to be coated with resist is dipped in the dip tank 50 with the top thereof facing downward. Next, the resist coated base material 10 is pulled up while being rotated to form a first layer, and baking is performed.

Here, in FIG. 7, 700 rpm in the upward direction.
When the resist was continuously supplied while rotating at, the degree of influence of gravity changed in the region near the bending point X2, and the nonuniform portion M1 was formed. On the other hand, when it is rotated downward at a predetermined number of revolutions (700 rpm), the film thickness has a shape opposite to the nonuniform portion in the region of the bending point X2 (that is, if the shape of FIG. 7 is a convex shape, In the case of downward rotation, a concave shape will be formed. Therefore, at least in the first layer, the concave non-uniform portion is formed.

Then, in the state where the reverse nonuniform portion is formed, as shown in FIG. 19, the direction of the top of the resist coating base material 10 is returned to the upward direction (the initial state), and the resist liquid L is added. A second pin is formed by performing a press pin for continuously supplying to the center of rotation and performing spin coating, and then performing main spinning and baking.

Here, when the second layer is formed, a non-uniform portion is formed in the region near the bending point X2 due to the formation of this layer, but the non-uniformity of the second layer is formed. Since the portion and the reverse non-uniform portion of the first layer have mutually opposite shapes, the non-uniformity is canceled as a whole. As a result, a uniform film thickness can be obtained regardless of the bending point.

In this way, the top of the resist-coated substrate is immersed downward in the dip tank to be rotated and pulled up to form the first layer, and after baking, the top of the resist-coated substrate is directed upward. By continuously supplying the resist solution to the center of rotation for spin coating and baking, it is possible to cancel the influence of gravity for each coating and obtain a uniform film thickness. In the above example, the resist coated substrate is pulled up while being rotated, but it is also possible to rotate the resist coated substrate after the substrate has been pulled up.

Although the case where the resist film is composed of two layers has been described in the present embodiment, it may be composed of n layers. However, when forming the n-layer, when n is an even number, it is preferable that the odd-numbered layer faces downward and the even-numbered layer faces upward.
In addition, when n is an even number, from the first layer to the (n /
Up to the 2) th layer, continuously downward, and the (n / 2 + 1) th layer
The structure after the second layer may be upward. The downward and upward directions may be reversed.

Furthermore, when n (n ≠ 1) is an odd number, the first layer to the kth (2 ≦ k ≦ n−1) th layer are directed downward, and the k + 1th and subsequent layers are directed upward. Good.
However, in this case, a method of adjusting and controlling each rotation speed and the like so that the total of the respective non-uniform portions up to the k-th layer and the total of the non-uniform portions after the (k + 1) -th layer are canceled Need to do. In such a case, a table or the like in which the shape of the film thickness of the non-uniform portion is defined in advance in accordance with each rotation speed and bending point position X2 is stored in the storage means 37,
It is preferable to control.

(Regarding Surface Roughness) Next, the surface roughness when processing the resist-coated base material used in the present embodiment will be described. First, an ultra-precision lathe for processing the substrate 10 to be coated with resist, for example, SPDT (S
single Point Diamond Turni
ng) will be described with reference to FIGS. 13 and 14.

As shown in FIG. 13, the ultra-precision lathe 100 has a fixing portion 111 for fixing a work 110 such as a resist-coated substrate and a diamond as a cutting edge for processing the work 110. A tool 112, a Z-axis slide table 120 that moves the fixed portion 111 in the Z-axis direction, and an X-axis slide table 122 that moves the fixed part 111 in the X-axis direction (or in addition to the Y-axis direction) while holding the diamond tool 112. , A surface plate 124 that movably holds the Z-axis slide table 120 and the X-axis slide table 122. In addition,
A rotary drive means (not shown) for rotationally driving either one or both of the fixed portion 111 and the diamond tool 112 is provided, and is electrically connected to a control means 138 described later.

Further, the ultra-precision lathe 100, as shown in FIG. 13, has a Z-direction drive means 131 for controlling the drive of the Z-axis slide table 120 and an X-axis slide table 122.
X-direction driving means 132 and Y-direction driving means 133 for controlling the driving in the X-axis direction (or additionally driving in the Y-axis direction), feed amount control means 134 for controlling the feed amount by these, and cutting Cutting amount control means 135 for controlling the amount
A temperature control means 136 for controlling the temperature, a storage means 137 for storing various control conditions, a control table or a processing program, and a control means 13 for controlling these respective parts.
8 is included.

As shown in FIG. 14, the diamond tool 112 comprises a diamond tip 113 which constitutes a main body portion.
And the rake face 1 consisting of the apex angle α formed at this tip
14 and a first flank 115 and a second flank 116 that form a side surface.

Ultra-precision lathe 10 having the above structure
At 0, it operates roughly as follows. That is, with respect to the set work 110, the diamond tool 1
The workpiece 110 is processed by the relative movement of the workpiece 12. At this time, the diamond tool 112
As shown in FIG. 14, since the cutting edge has an R-bite structure, the point where the cutting edge hits changes sequentially,
Strong against abrasion.

In the present embodiment, the above resist-coated base material 1 is formed by using the above-described ultra-precision lathe.
When machining 0, the feed amount and the depth of cut are controlled while controlling the temperature so that the surface roughness of the curved surface is, for example, 50 nm or less, and more preferably 20 nm or less. Becomes

After that, the tool mark which looks rainbow-colored (structural color due to diffraction) is polished and polished until the rainbow (structural color) is no longer visible.

The term "surface roughness" as used herein means that in FIG.
As shown in (B), a certain surface is defined as a roughness curve f (y), a portion having a measurement length l is extracted from the roughness curve f (y) in the direction of its center line, and the center of the extracted portion is extracted. The roughness curve is x = f with the line as the X axis and the vertical magnification direction as the Y axis.
When represented by (y), the value Ra obtained by the equation in the figure
Is meant.

When the resist-coated base material 10 is a lens, it is necessary that the optical surface has a surface roughness of, for example, about 20 nm or less. However, when it is assumed that the lens is not a lens, the thickness is not limited to this, and may be 75 nm or less where a difference in film thickness distribution is recognized. Therefore, it is set to about 75 nm or less, more preferably about 20 nm.
nm or less.

As described above, in this embodiment, the surface roughness of the tool mark or the like can be removed, so that the optical evaluation at the time of measuring the film thickness is not hindered. Moreover, all the measurement results can be fed back to the examination of the resist coating method.

(Regarding Processing Procedure) Next, when the resist is applied to the resist-coated base material having the above-described structure, the preconditioning process, and further, the first step in the above-mentioned resist application The processing procedure and the second processing procedure will be described in detail.

(Processing Step) First, when the resist-coated base material is cut, an ultra-precision lathe such as SPDT (S
single Point Diamond Turni
ng), diamond feeding is performed to control the feed amount and the cutting amount while controlling the temperature to obtain a curved surface roughness 50 [nm] or 20 nm (cutting step). After that, the tool mark which looks like a rainbow color is visually abraded until the rainbow disappears (polishing step). When the substrate 10 to be coated with resist is processed and completed in this way, resist coating is next performed.

(Resist Coating Step) (First Processing Procedure) Next, the coating step when resist is coated on the resist coating base material having the above-described structure will be described together with the action of the resist coating base material. 15 to 17
Will be described with reference to.

The substrate 10 to be coated with resist, which has been transported by a transporting means (not shown), is placed on the spin coater chuck 20 and set (step, hereinafter referred to as "S" 10).
1). At this time, since the spin coater chuck 20 has a recess, the resist-coated base material 10 is uniquely held and fixed by being inserted into the recess. Then, the alignment operation of the spin coater chuck 20 is performed by the driving unit 30 at the predetermined resist dropping position.

Next, the rotation speed control means 36 is used for the period T until the rotation speed reaches the predetermined first rotation speed (for example, 200 rpm).
1 to raise the spin coater chuck 20 to θ
The direction driving means 35 rotates in the θ direction to start the press pin in the period T2 (S102).

Then, while the resist coating base material 10 is rotated, a predetermined amount of the resist liquid L is continuously flowed down and supplied by the coating material coating means 31 (S103). At this time, various control conditions such as a resist coating amount and environmental conditions according to the number of rotations of the spin coater chuck 20 so that the film thickness becomes uniform are the coating amount control means 3.
3 and the rotation speed control means 36 and the control means 49. For example, in the present embodiment, when the inner diameter of the supply needle of the coating material applying unit 31 is 0.2 mm for the resist 100 cp, the supply pressure is, for example, 0.3.
It becomes about MPa.

With this press pin, the resist is continuously flowed down to the top of the curved surface portion 12 of the resist-coated base material 10, and the resist-coated base material 10 is rotated at a predetermined first rotational speed. The resist flown down to the apex due to the rotation maintains a substantially uniform film thickness, and the peripheral curved surface portion 16 and the peripheral flat surface portion 1 around the curved surface portion 12 from the apex.
The resist is applied while flowing smoothly toward 4 (rotational application step).

During this time, when the resist is continuously supplied and rotated at a predetermined number of rotations, the resist L changes from the curved surface portion 12 to the surrounding curved surface portion 16 as shown by an arrow T in FIG.
It will be spread to the surrounding plane portion 14 via.

At this time, as shown in FIG. 3, from X1 to X
The resist (L shown in FIG. 2) spreads along the curved surface of the curved surface portion 12 when spreading to the curved surface portion 12 up to 2, and then spreads on the curved surface portion 12 when reaching the surrounding curved surface portion 16. The speed will be about the same as or faster than the speed of. As a result, when the curved surface portion 12 and the peripheral flat surface portion 14 are discontinuous surfaces, deceleration caused by the impact generated when the resist hits the peripheral flat surface portion 14 causes a nonuniform film thickness as compared with the case where the film thickness becomes nonuniform. And surrounding curved surface portion 16
The continuous surface spreads the resist smoothly.

Further, in this case, the film thickness is uniform in the curved surface portion 12 and the peripheral flat surface portion 14, but in the peripheral curved surface portion 16, it is conceivable that a nonuniform region may occur in the boundary region. Uneven portion 13 for correcting film thickness
These non-uniform portions are eliminated by forming the.

Next, in the period T3, a determination process is performed as to whether or not 2 seconds have elapsed (S10).
4). In this determination process, when it is not determined that 2 sec has elapsed, the process returns to S103. On the other hand, when it is determined that 2 seconds have passed in the determination processing of S104, the coating material supply time control means 34
Applies the coating material 31 so as to stop the resist supply.
To stop the resist supply (S
105).

Next, in the period T3, after increasing the number of revolutions by using the number-of-revolutions control means 36 to the second number of revolutions (for example, 700 rpm) which is higher than the first number of revolutions,
The main spin will be started in the period T4 (S1
06). In this main spin, the rotation speed is 700 rp, for example.
It is preferable to set m and rotate for a period of 600 sec.

In this main spin, the continuous supply of resist is stopped, and the resist-coated base material 10 coated with the resist is rotated at a second rotation speed higher than the first rotation speed (rotation step). ).

At this time, the spin coater chuck 20 is moved downward by the Z direction drive means 41 (S
107). Here, in order to move, the gravity control means 43
Is controlled to move at an acceleration of, for example, 9.8 [m / (s ^ 2)]. Thereby, the influence of gravity applied to the resist can be removed.

Next, (2 * h [m] /9.8 [m / (s
^ 2)]) ^ (1/2) [sec] is determined (S108). In this determination process, when it is determined that the time has not elapsed, the process returns to S107. On the other hand, in the determination process of S108, when it is determined that the time has already passed, the downward movement of the spin coater chuck 20 is stopped by the Z-direction driving means 41 (S10).
9).

Then, a baking (heating) process is applied to the resist coated base material 10 (S110). At this time, the temperature is set to about 170 ° C. and heating is performed for about 20 minutes.

As described above, according to this processing procedure, a downward force is applied to the resist solution on the curved surface portion during the rotation, so that the gravity control means 43 moves the downward force only in the rotation section to cause the downward movement. An upward force that cancels the force is generated, and as a result, the influence of gravity applied to the resist solution during rotation can be eliminated. In particular, when the resist liquid L is operated downward only during the period when the resist liquid L reaches the inclined surface of the curved surface portion 12, the effect becomes remarkable.
Therefore, by moving downward in the vertical direction during rotation, it is possible to reduce the influence of gravity applied to the resist solution on the curved surface portion, and it is possible to contribute to making the resist film thickness distribution uniform.

After the resist is applied, only the curved surface portion 14 is cut by cutting the peripheral flat surface portion 14 as shown in FIG. 4 and the peripheral curved surface portion 16 as shown in FIG. The resist-coated base material 10 coated with the resist can be configured.

(Second Processing Procedure) Next, another processing procedure (second processing procedure) for resist coating will be described with reference to FIG.
This will be described with reference to FIGS.

First, the top of the substrate 10 to be coated with resist is turned downward by the ψ-direction rotation driving means 44a of the up-down inverting means 24 (S201). At this time, as a premise,
The base material fixing means 47 prevents the base material 10 to be coated with resist from being separated from the spin coater chuck 20.
The resist coated base material 10 and the spin coater chuck are fixed.

Next, using the XYZ direction moving means 44b and the like, the spin coater chuck 2 is turned downward.
The resist coated substrate 10 held at 0 is the dip tank 5
The solution in 0 is impregnated (S202). After the impregnation, the XYZ direction moving means 44b or the like is used to move in the arrow Z2 direction in FIG. 19 in a state where the resist coated substrate 10 is pulled up (S20).
3).

[0207] Further, in the state in which it is faced down, for example, 6
During 00 sec, the θ direction rotation driving means 35 or the like rotationally drives at a predetermined third rotation speed (for example, 700 rpm) to perform the “main spin” (S204). Then, a baking (heating) process is performed at a predetermined temperature, for example, 170 degrees for a period of 20 minutes (S205).

Here, when the film is rotated downward at a predetermined number of rotations, the film thickness has a shape opposite to that of the nonuniform portion in the region of the bending point X2 (that is, if the shape in FIG. 7 is a convex shape, the downward rotation is performed). In this case, a concave shape will be formed. Therefore,
At least in the first layer, the concave non-uniform portion is formed.

After the resist-coated substrate 10 is turned up by the ψ-direction rotation driving means 44a (S20).
6), the spin coater chuck 20 is rotated by the θ-direction driving unit 35 to perform press pin (S207), and the coating material coating unit 31 continuously flows down the resist L onto the resist coating base material 10 (S208). ).

At this time, the control means 49 instructs the coating material supply time control means 34 to supply the resist from the coating material coating means 31 for a certain period during the press pin, and at the same time the predetermined fourth rotation speed ( Θ at 200 rpm, for example
The coating amount control unit 3 instructs the rotation number control unit 36 to rotate (provides a control signal) to rotate the direction rotation driving unit 35, and further controls the resist coating amount and viscosity.
3. Control the viscosity control means 32. For example, in the present embodiment, when the inner diameter of the supply needle of the coating material applying unit 31 is 0.2 mm with respect to the resist 100 cp, the supply pressure is, for example, about 0.3 MPa.

Next, a determination process is performed as to whether or not 2 sec has elapsed (S209). If it is not determined that 2 sec has elapsed in this determination process, the process returns to S208. On the other hand, when it is determined in the determination process of S209 that 2 seconds have elapsed, the coating material supply time control unit 34 instructs the coating material coating unit 31 to stop the resist supply, and the resist supply is performed. Will be stopped (S210).

Next, the fifth rotation speed which is higher than the fourth rotation speed is set.
After the rotation speed is increased to the rotation speed (for example, 700 rpm) using the rotation speed control means 36, the main spin is started (S211). In this main spin, it is preferable that the number of rotations is set to 700 rpm and the spinning is performed for a period of 600 sec. At this time, S107 and S108 of the first processing procedure may be performed.

Then, a baking (heating) process is applied to the resist coated base material 10 (S212). At this time, the temperature is set to about 170 ° C. and heating is performed for about 20 minutes.

In this way, in the state where the reverse non-uniform portion is formed, the direction of the top of the resist-coated substrate 10 is returned to the upward direction (the initial state), and the resist liquid L is continuously rotated around the center of rotation. A second pin is formed by performing a press pin for supplying and spin-coating the product, then performing a main spin and baking.

Here, when the second layer is formed, a non-uniform portion is formed in the region near the bending point X2 due to the formation of this layer, but the non-uniformity of the second layer is formed. Since the portion and the reverse non-uniform portion of the first layer have mutually opposite shapes, the non-uniformity is canceled as a whole. As a result, a uniform film thickness can be obtained regardless of the bending point.

As described above, according to the second processing procedure, the base material to be coated with resist is faced downward, soaked in the dip bath and pulled up while being rotated to form the first layer. With the top of the material facing upward, the resist solution is continuously supplied to the center of rotation for spin coating, and baking is performed to cancel the effect of gravity for each coating and obtain a uniform film thickness. it can.

As described above, according to the present embodiment, the size of the base material to be coated with resist is set to the minimum size required for uniform film thickness, thereby reducing the size of the base material in the manufacturing stage. can do. Therefore, the processing of the base material does not take time, the construction period can be shortened, and the throughput is improved. In addition, cost reduction can be achieved by reducing the amount of members used.

Further, the unevenness portion for correcting the film thickness is formed so as to be recessed in a portion where the uneven portion rises and the thickness is large, and the film thickness is formed in a portion where the uneven portion has a small thickness. The thickness of the “base material to be coated with resist + resist” can be made uniform by making the correction uneven portion convex.
As a result, the film thickness can be made uniform in the first layer. Therefore, the height difference of the non-uniform portion generated in the second and subsequent layers should be minimized (within the allowable range) to make the film thickness almost uniform. You can

Further, if the unevenness portion for correcting the film thickness is formed in a shape capable of absorbing the characteristic shape according to the characteristic shape of the uneven portion due to the characteristics of the n-th layer, the uneven portion of each layer due to the multilayer formation is formed. It is still more preferable because it is possible to eliminate all the influences of (1) and (5) and finally obtain a substantially uniform film thickness. In this way, by forming the unevenness portion for film thickness correction on the resist-coated substrate in advance, the surface of the final resist film can be made uniform.

Further, the viscosity is approximately 150 [m so that gravity and centrifugal force applied to the resist on the curved surface can be balanced.
Pa · S] or less resist liquid, approximately 700 [rpm]
By repeating the step of spin coating and the baking step, a substantially uniform desired film thickness can be obtained.

Further, by continuously supplying the resist solution into the press pin with respect to the rotation center axis of the substrate to be coated with resist, it is possible to compensate for the decrease in the resist solution at the center of rotation due to rotation. The film thickness distribution does not monotonically increase from the center of rotation to the periphery of the resist-coated substrate.

Furthermore, since a downward force is applied to the resist solution on the curved surface during rotation, an upward force that cancels the downward force is generated by moving the downward direction by the gravity control means only in the rotating section. As a result, the effect of gravity applied to the resist solution during rotation can be eliminated. In particular, the resist solution L is
The effect becomes remarkable when the downward operation is performed only during the time when the wire reaches the slope of No. 2. Therefore, by moving downward in the vertical direction during rotation, it is possible to reduce the influence of gravity applied to the resist solution on the curved surface portion, and it is possible to contribute to making the resist film thickness distribution uniform.

Furthermore, the top of the substrate to be coated with resist is faced downward, immersed in a dip bath and pulled up while being rotated to form the first layer. After baking, the top of the substrate to be coated with resist is faced up to form a resist solution. Is continuously supplied to the center of rotation for spin coating and baking,
A uniform film thickness can be obtained by canceling the influence of gravity.

Since the surface roughness such as the tool mark can be removed, the optical evaluation at the time of measuring the film thickness is not hindered. Moreover, all the measurement results can be fed back to the examination of the resist coating method.

Further, the centrifugal force generated during spin coating is
It is evenly transmitted to the resist on the curved surface portion, and there is no obstacle when the resist is spread and spread to the periphery, and a uniform film thickness distribution is obtained on the curved surface portion. Further, the nonuniform film thickness portion due to the stress when the resist droplets are separated from the base material is generated only on the peripheral curved surface portion.

Further, by forming the concave portion or the convex portion as the position recognizing portion on the peripheral flat surface portion of the substrate to be coated with resist, the resist is not spread over the position recognizing portion. Recognition accuracy is improved.

Further, since the rotation center of the resist-coated substrate having a curved surface and the rotation center of the spin coater chuck coincide with each other, the centrifugal force generated during spin coating is uniformly transmitted to the resist on the curved surface portion, and An even film thickness distribution can be obtained.

[Second Embodiment] Next, a second embodiment according to the present invention will be described with reference to FIG. Note that, in the following, description of substantially the same configuration as that of the first embodiment will be omitted, and only different portions will be described.

Although the resist coating step is disclosed in the above-mentioned first embodiment, in this example, the steps of the entire process including the above steps, particularly the gold for manufacturing the optical lens such as the optical element by molding. A process of manufacturing a mold or the like will be described.

First, the above-mentioned ultra-precision lathe is machined to perform aspherical surface machining of a die (electroless nickel or the like) (machining step). Next, as shown in FIG. 21 (A), resin molding of the base material 200 having the hemispherical surface is performed by a mold (resin molding step). Further, the base material 200 is washed and then dried.

Next, the surface of the resin base material 200 is treated (resin surface treatment step). In this step, for example, A
Steps such as u vapor deposition will be performed. Specifically, FIG.
As shown in FIG. 1 (B), the base material 200 is positioned,
The spinner is rotated while continuously flowing down the resist L, and the same spin coating as in the first embodiment is performed. Also,
Also pre-paque.

After the spin coating, the thickness of the resist film is measured and the resist film is evaluated (resist film evaluation step). Further, as shown in FIG. 21C, the base material 200 is positioned, and exposure or drawing with an electron beam is performed while the base material 200 is controlled by the X, Y, and Z axes, respectively.

Next, the surface smoothing treatment of the resist film L on the base material 200 is performed (surface smoothing step). Further, FIG.
As shown in (D), development processing is performed while positioning the base material 200 and the like (developing step). Furthermore, surface hardening treatment is performed.

Next, a step of evaluating the resist shape is carried out by SEM observation, a film thickness measuring instrument, etc. (resist shape evaluation step).

After that, an etching process is performed by dry etching or the like.

After the resist is applied, the peripheral flat surface portion and the peripheral curved surface portion are cut in any of these steps.

Next, in order to prepare the mold 204 for the surface-treated base material 200, as shown in FIG. 21 (E), after the mold electroforming pretreatment is carried out, the electroforming process is performed. Then, as shown in FIG. 21F, the base material 200 and the mold 20 are
The process of peeling off 4 and 4 is performed.

Mold 2 separated from the surface-treated base material
Surface treatment is performed on 04 (mold surface treatment step).
Then, the mold 204 is evaluated. After evaluation, the mold 2
A molded product is prepared using 04. Then, the molded product is evaluated.

As described above, according to this embodiment, it is possible to easily manufacture the molding die for injection molding the above-mentioned optical element.

Although the apparatus and method according to the present invention have been described in accordance with some specific embodiments thereof,
Various modifications can be made to the embodiments described in the text of the present invention without departing from the spirit and scope of the present invention. For example, in each of the above-described embodiments, the peripheral flat surface portion is formed as a flat surface, but it may be formed in a taper that inclines downward toward the outside of the periphery, which may hinder the uniform thickness of the curved surface portion. It may be formed as a slightly curved curved surface to the extent that it does not occur, or may partially have curved surfaces or corners.

Further, the radii of curvature of the curved surfaces having radii R1 and R2 can be arbitrarily set as long as the above conditions are satisfied.

Further, although the case where gravity control is performed in the main spin has been described, the present invention is not limited to this, and gravity control may be performed by a press pin. In this case, in the spin coating step, the coating material is continuously flown down to the top of the curved surface portion of the base material to be coated, and is flowed down to the top portion as the base material to be coated is rotated at a predetermined rotation speed. The applied material is
While coating the coating material while flowing down smoothly from the top toward the peripheral surface around the curved surface while maintaining a substantially uniform film thickness, the substrate to be coated on the side opposite to the film thickness forming surface is coated. It moves at a predetermined acceleration in the direction of the rotation axis. At this time, it is preferable that the movement with the acceleration is performed until the coating material covers the curved surface portion of the base material to be coated.

Further, after forming the first layer in the second processing procedure, each layer may be formed by using any of the coating methods of the first and second processing procedures. At that time,
Adding gravity control or the like is also optional. For example, the top portion of the base material to be coated on which the first layer of the coating material is formed is directed upward, and then, in a spin coating step, the top portion of the curved surface portion is applied to the top portion of the first layer from above. The coating material is continuously flowed down, and the coating material flowed down to the top portion according to the rotation of the base material to be coated at a predetermined first rotation speed,
The second layer of the coating material is applied while maintaining a substantially uniform film thickness on the first layer and smoothly flowing down from the top toward the peripheral surface around the curved surface.

The continuous supply of the coating material is stopped, and the base material coated with the coating material of the second layer is rotated at a second rotation speed higher than the first rotation speed. However, the base material to be coated may be moved at a predetermined acceleration in the direction of the rotation axis on the side opposite to the film thickness forming surface.

On the other hand, after the top of the base material to be coated on which the first layer of the coating material is formed is faced upward, in the spin coating step, the first layer is applied to the top of the curved surface portion. The coating material is continuously flown down from above, and the coating material flowed down to the top in association with the rotation of the base material to be coated at a predetermined first rotation speed is on the first layer. Forming a film thickness on the substrate to be coated while applying a second layer of the coating material while smoothly flowing down from the top to the peripheral surface around the curved surface while maintaining a substantially uniform film thickness. You may move with a predetermined acceleration toward the rotating shaft direction on the opposite side to a surface.

Further, the above embodiment includes various steps, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. That is,
It goes without saying that the embodiments include the embodiments described above or a combination of any of them with any of the modifications. Further, it may be a configuration in which some of the constituent elements are deleted from all the constituent elements shown in the embodiment.

[0247]

As described above, according to the present invention, the coating material is continuously supplied to the rotation center of the substrate to be coated during the rotation of the spin coating process, so that the rotation center portion of the rotation can be reduced. The reduction of the coating material can be compensated, and the film thickness distribution does not monotonically increase from the rotation center portion on the curved surface portion of the coating base material to the boundary region with the peripheral surface portion.

In addition, since a downward force is applied to the coating material on the curved surface portion during the rotation of the rotating step, an upward force that cancels the downward force by moving the downward force by the gravity control means only in the rotating section. Is generated, and as a result, the influence of gravity applied to the coating material during rotation can be eliminated. In particular, when the coating material is moved downward only during the time when the coating material reaches the inclined surface of the curved surface portion, the effect becomes remarkable. Therefore, by moving it downward during rotation, it is possible to reduce the influence of gravity applied to the coating material on the curved surface portion, and it is possible to contribute to making the film thickness distribution of the coating material uniform.

[0249] Furthermore, the top of the base material to be coated is faced downward, immersed in a solution tank and pulled up while being rotated to form the first layer, and after heating, the top part of the base material to be coated is faced up and the coating material is rotated. By continuously supplying to the central portion, spin coating and heating, the influence of gravity can be canceled and a uniform film thickness can be obtained for each coating.

Further, the distance from the center of rotation of the curved surface portion to the peripheral edge of the peripheral surface portion is approximately 4 times the radius of the curved surface portion.
By forming less than double, the size of the substrate to be coated,
By setting the minimum size required for uniform film thickness, the base material size in the manufacturing stage can be reduced. Therefore, the processing of the base material does not take time, the construction period can be shortened, and the throughput is improved. In addition, cost reduction can be achieved by reducing the amount of members used.

Furthermore, the unevenness portion for correcting the film thickness is formed so as to be recessed in a portion where the uneven portion generated in the boundary region between the curved surface portion and the peripheral surface portion has a large bulge, and the uneven portion is formed. With respect to the portion where the thickness is small, the unevenness portion for correcting the film thickness is made to be convex, so that the thickness of the “coated substrate + coating material” can be made uniform. by this,
Since the film thickness can be made uniform in the first layer, 2
It is possible to make the film thickness substantially uniform by keeping the height difference of the non-uniform portion generated in the layers after and after the minimum level (within the allowable range).

Further, if the unevenness portion for film thickness correction is made to have a shape capable of absorbing the characteristic shape in accordance with the characteristic shape of the uneven portion due to the characteristics of the plurality of layers, the uneven portion of each layer due to the multilayer formation is formed. It is still more preferable because it is possible to remove all the influences and finally obtain a substantially uniform film thickness. In this way, by forming the unevenness portion for film thickness correction on the substrate to be coated in advance, the surface of the final layer can be made uniform.

In addition, the number of rotations in the spin coating step is 200 to 7
By setting it within the range of 00 [rpm], the viscosity is about 150.
The coating material of [mPa · S] or less can be appropriately spread on the curved surface portion of the base material to be coated before the coating material starts to dry.

In addition, the rotation speed of the rotation process is set to approximately 700 [r
pm] balances the gravity and centrifugal force applied to the coating material on the curved surface, and the viscosity is approximately 150 [mPa.
The coating material of S or less can be spread evenly, and a substantially uniform desired film thickness can be obtained by repeating the rotating step and the baking step.

Furthermore, when the element is processed, it is possible to remove the surface roughness such as the tool mark by processing it with an ultra-precision lathe so that it has a predetermined surface roughness and polishing it. , It does not hinder the optical evaluation when measuring the film thickness. In addition, all the measurement results can be fed back to the examination of application of the coating material.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a schematic configuration of an entire coating agent coating device of the present invention.

2 (A) is a plan view showing a resist-coated substrate to be processed by the resist coating apparatus of FIG. 1, and FIG. 2 (B) is a partial view of the resist-coated substrate. It is a schematic explanatory drawing which showed the different cross section.

FIG. 3 is an explanatory diagram showing an example of a process of processing a resist-coated base material processed by the resist coating apparatus of FIG.

FIG. 4 is an explanatory diagram showing an example of a processing step of a resist-coated substrate to be processed by the resist coating apparatus of FIG.

5 is an explanatory diagram showing an example of a process of processing a resist-coated base material processed by the resist coating apparatus of FIG.

FIG. 6 is an explanatory diagram showing a relationship between a distance from a rotation center of a base material and a film thickness according to a boundary region position between a peripheral curved surface portion and a peripheral flat surface portion.

FIG. 7 is an explanatory diagram showing the relationship between the number of revolutions, the distance from the center of rotation of the substrate in each layer, and the thickness of the resist when the resist is continuously supplied into the press pin.

8A and 8B are explanatory views for explaining the mechanism of spin coating, FIG. 8A shows a plane, and FIG. 8B shows a curved surface.

FIG. 9 is an explanatory diagram showing a relational expression for explaining a mechanism of spin coating on a plane.

FIG. 10 is an explanatory diagram showing a relational expression for explaining the mechanism of spin coating on a curved surface.

11A to 11D are explanatory diagrams for explaining the relationship between the distance from the rotation center and the gravity and centrifugal force applied to the resist according to the rotation speed. (A)
Shows the relationship between the distance from the center and the height.
Shows the case of 700 rotations, FIG. 7C shows the case of 800 rotations, and FIG. 7D shows the case of 600 rotations.

12 (A) and (B) are explanatory views for explaining a change over time in a film thickness on a curved surface due to a difference in viscosity and the number of revolutions. FIG. ) Is 200
Each case of 0 rotation is shown.

FIG. 13 is a functional block diagram showing an example of a configuration of an ultra-precision lathe used for processing a base material.

14 is a perspective view showing an example of a cutting edge of a diamond tool in the ultra-precision lathe shown in FIG.

FIG. 15 is a flowchart showing an example of a processing procedure of a coating material coating process performed by the coating material coating device of the present invention.

FIG. 16 is an explanatory diagram for explaining a change over time in the number of rotations when a resist is continuously supplied into a press pin.

FIG. 17 is an explanatory diagram showing a state in which the spin coater chuck is lowered.

FIG. 18 is a flowchart showing an example of a processing procedure of a coating material coating process performed in the coating material coating device of the present invention.

FIG. 19 is an explanatory diagram for explaining an outline of a process of immersing in a dip tank.

20 (A) to 20 (C) are explanatory views for explaining the relationship between the distance from the substrate center and the film thickness when spin is started from the state where the resist solution is stored on the substrate. Is.

21 (A) to 21 (F) are explanatory views for explaining an overall processing procedure when a molding die is formed using a base material.

22A is an explanatory diagram showing a process in a conventional resist coating apparatus, FIG. 22B is an explanatory diagram for explaining surface roughness, and FIG. FIG. 6 is an explanatory diagram for explaining a state in which a tool mark is formed.

FIG. 23 is an explanatory diagram showing the relationship between the rotation speed and the resist film thickness distribution when the rotation speed in the press pin is changed.

FIG. 24 is an explanatory diagram showing a resist film thickness distribution of a plurality of resist-coated base materials.

FIG. 25 is an explanatory diagram showing a baseline which is an average value of the resist film thickness distributions of the plurality of resist-coated base materials shown in FIG. 24 when displacement amounts from a predetermined reference value are calculated. Is.

26 is an explanatory diagram showing an error in the resist film thickness distribution shape of the plurality of resist-coated base materials shown in FIG. 24, which is calculated based on the baseline shown in FIG. 25.

FIG. 27 is an explanatory diagram for explaining a method of measuring the film thickness of the resist coated on the resist-coated substrate.

28 is an explanatory diagram showing a spectrum (reflectance spectrum) analysis of reflected light in the state shown in FIG. 27. FIG.

[Explanation of symbols]

1 Resist coating device (coating material coating device) 10 Resist-coated substrate (coated substrate) 12 curved surface 13 Unevenness for correcting film thickness 14 Peripheral plane 16 Surrounding curved surface 20 Spin coater chuck (holding member) 31 coating material coating means 32 Viscosity control means 34 Coating material supply time control means 35 θ-direction rotation drive means 36 Rotation speed control means 37 storage means 41 Z-direction drive means 43 Gravity control means 44 upside down means 47 Base material fixing means 49 control means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Osamu Masuda             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Association             In-house (72) Inventor Akiko Kuji             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Association             In-house F-term (reference) 4D075 AB03 AC64 AC88 AC94 CA48                       DA36 DC21                 4F042 AA02 AA06 EB04 EB08 EB17                       EB29

Claims (72)

[Claims] 1. A coating material coating method for rotating a coating target material to which a coating material is coated to coat the coating material on the coating target substrate, wherein the coating target substrate has a curved surface portion. Along with having the coating material continuously flowed down to the top of the curved surface portion of the coated substrate, the coating material flowed down to the top by rotating the coated substrate at a first rotation speed. The coating material is
The spin coating step of applying from the top toward the peripheral surface portion around the curved surface section, stopping the flow of the coating material, and applying the coating material to which the coating material is applied by the spin coating step, And a rotation step of rotating at a second rotation speed higher than the first rotation speed. 2. The coating material according to claim 1, wherein, in the spin coating step, the base material to be coated is moved at a predetermined acceleration in a direction of a rotation axis opposite to a film thickness forming surface. Application method. 3. The coating material according to claim 2, wherein in the spin coating step, the movement at the acceleration is performed until the coating material covers the curved surface portion of the base material to be coated. Application method. 4. A coating material coating method for rotating a coating substrate to which a coating material is applied to coat the coating material on the coating substrate, wherein the coating substrate has a curved surface portion. Along with having a coating step of impregnating the solution tank in which the coating material is immersed with the top of the curved surface portion of the substrate to be coated facing down, and applying the coating material in a state where the top is facing downward. A method of applying a coating material, comprising: pulling up the substrate to be coated soaked in the substrate and rotating the substrate at a third rotation speed. 5. A heating step of heating the base material to be coated at a predetermined temperature after a rotating step of rotating the base material to be coated immersed in the coating material at a predetermined rotation speed while pulling up the base material to be coated, A step of directing the top part of the base material to be coated on which the first layer of the coating material is formed upward, and continuously applying the coating material from above the first layer to the top part of the curved surface part. The coating material that has flowed down and flowed down to the top in accordance with the rotation of the substrate to be coated at a predetermined first rotation speed while maintaining a substantially uniform film thickness on the first layer. The spin coating step of applying the second layer of the coating material while smoothly flowing down from the top toward the peripheral surface around the curved surface, further comprising: Application method. 6. After the spin coating step, the continuous supply of the coating material is stopped, and the base material coated with the coating material of the second layer is applied to a substrate having a rotation speed higher than the first rotation speed. The coating material coating method according to claim 5, further comprising a rotation step of rotating at a rotation speed of 2. 7. The coating material coating method according to claim 6, further comprising a heating step of heating the substrate to be coated at a predetermined temperature after the rotating step. 8. The method further comprising the step of repeating the spin coating step, the rotating step, and the heating step to form the coated substrate on which a coating material having a desired film thickness is formed. Item 8. A method for applying a coating material according to any one of items 5 to 7. 9. A coating material coating method for coating a coating material on a coating substrate, wherein the coating substrate has a curved surface portion, and the coating material is coated on the coating substrate. A coating step, a rotating step of rotating the coated substrate coated with the coating material by the coating step, and a curing of the coated substrate coated with the coating material by the rotating step at a predetermined temperature A coating material coating method comprising repeating the curing step to form the coating base material on which the coating material having a desired film thickness is formed. 10. A step of applying the coating material onto the coating base material by impregnating a solution tank in which the coating material is immersed with the top of the curved surface portion of the coating base material facing downward, In the impregnating step, the substrate to be coated that has been dipped in the coating material is pulled up, and is rotated at a third rotation speed with the top portion facing downward, and the rotation speed is the third rotation speed. A heating step of heating the coated base material coated with the coating material at a predetermined temperature, with the top of the curved surface portion of the coating base material facing upward, and applying the coating material to the top of the curved surface portion. While continuously flowing down, by rotating the substrate to be coated at a first rotation speed, the coating material flowed down to the apex is applied from the apex toward the peripheral surface around the curved surface. Spin coating step of coating material, and the coating material A rotation step of stopping the flow-down, and rotating the substrate to be coated on which the coating material has been applied in the spin coating step at a second rotation speed higher than the first rotation speed; The heating method of heating the said to-be-coated base material with which the said coating material was apply | coated by several rotations is heated at a predetermined temperature, The coating material application method of Claim 9 characterized by the above-mentioned. 11. The impregnating step with the top of the substrate to be coated facing down, the rotating step of rotating at the third rotation speed, the first treatment for performing the heating step, and the substrate to be coated. 11. The rotating coating step with the top of the material facing upward, the rotating step of rotating at the second rotation speed, and the second treatment of performing the heating step are alternately repeated. The method for applying the coating material according to. 12. The first step after the first step of performing the impregnating step, the rotating step of rotating at the third rotational speed with the top of the base material to be coated facing downward, and the first step of performing the heating step.
In addition to performing the above process, the top of the substrate to be coated faces upward, the spin coating process, the rotating process of rotating at the second rotation speed, and the second process of performing the heating process. 11. The second process is performed.
The method for applying the coating material according to. 13. The coating material is continuously flowed down to the top of the curved surface portion with the top of the curved surface portion of the coating substrate facing upward, and the coating substrate is rotated at a first rotation speed. By rotating the coating material flowing down to the top portion toward the peripheral surface portion around the curved surface portion from the top portion, the rotation coating step of applying the coating material, and stopping the flowing down of the coating material. A rotating step of rotating the substrate to be coated on which the coating material has been applied in the spin coating step at a second rotation speed higher than the first rotation speed; A heating step of heating the base material coated with the coating material at a predetermined temperature, and impregnating the solution tank in which the coating material is immersed with the curved surface portion of the base material facing downward. By applying the coating material to the base material to be coated An impregnating step of applying the above, a rotating step of pulling up the substrate to be coated immersed in the coating material in the impregnating step, and rotating at a third number of revolutions with the top part facing downward, The coating material coating method according to claim 9, further comprising: a heating step of heating the coating target material coated with the coating material at a rotation speed of 3 at a predetermined temperature. 14. The spin coating step with the top of the substrate to be coated facing upward, the rotating step of rotating at the second rotational speed, the second treatment for performing the heating step, and the coating object. The impregnating step with the top of the substrate facing downward;
14. The method for applying a coating material according to claim 13, wherein the rotating step of rotating at the number of rotations and the first treatment of performing the heating step are alternately repeated. 15. Prior to the second treatment including the rotation coating step, the rotation step of rotating at the second number of revolutions with the top of the substrate to be coated facing upward, and the second step including the heating step. In addition to the second treatment, the impregnating step with the top of the coated substrate facing downward, the rotating step of rotating at the third rotation speed, and the first step of performing the heating step are followed by the first step. The coating material coating method according to claim 13, wherein the treatment 1 is performed. 16. The method according to claim 1, further comprising, after the rotating step, a curing step of curing the base material coated with the coating material. Application method. 17. The method according to claim 1, further comprising, after the rotating step, a heating step of heating the base material coated with the coating material at a predetermined temperature. The method for applying a coating material according to item. 18. The predetermined temperature in the heating step is 10
The coating material application method according to claim 17, wherein the application temperature is 0 ° C. to 200 ° C. 19. The coating material coating method according to claim 1, further comprising a shape processing step for preliminarily forming a shape of the base material to be coated. 20. In the shaping step, the peripheral surface portion includes a peripheral flat surface portion formed around the curved surface portion, and the peripheral flat surface portion and the curved surface portion so that the coating material flows down smoothly. 20. The coating material coating method according to claim 19, further comprising: a peripheral curved surface portion formed in a boundary region with 21. In the shape processing step, a film thickness correcting uneven portion for correcting a film thickness after coating a coating material is formed at a boundary region position between the peripheral surface portion and the curved surface portion. The coating material coating method according to claim 20. 22. In the shape processing step, the curved surface portion is closer to the center of the top portion to which the coating material flowing down adheres,
The first radius of the curved surface portion includes an effective curved surface portion up to a predetermined effective diameter required to have a substantially uniform film thickness distribution after coating the coating material, and the first radius of the curved surface portion constitutes the peripheral curved surface portion. The boundary area position between the peripheral flat surface portion and the peripheral curved surface portion, which is formed with a radius of 1 to 10 times and the inclination of the tangent line of the second radius is substantially zero, is effective in the effective curved surface portion. The coating material coating method according to claim 20, wherein the coating material is formed at a position spaced apart from at least twice the diameter. 23. In the shape processing step, the distance from the center of rotation of the curved surface portion to the peripheral edge of the peripheral curved surface portion is formed to be 4 times or less the radius of the curved surface portion. 23. The coating material coating method according to claim 22. 24. The shape processing step includes a cutting step of cutting the base material to be coated.
The method for applying the coating material according to. 25. The coating material coating method according to claim 24, wherein the surface roughness of the curved surface portion is set to 50 nm or less by the cutting process. 26. The coating material coating method according to claim 24, wherein the shape processing step includes a polishing step of polishing the curved surface portion. 27. The viscosity of the coating material is approximately 150 mPa.
・ Claim 1 or 2 wherein s or less
6. The coating material coating method according to any one of 6 above. 28. The temperature of the coating material is 22 ° C. to 24 ° C.
The coating material coating method according to any one of claims 1 to 27, wherein 29. The method according to any one of claims 1 to 3, wherein the second rotation speed is set to around 700 rpm.
The coating material coating method according to any one of claims 10 to 15. 30. In the spin coating step, the first number of rotations is set to 200 rpm to 700 rpm, and any one of claims 1 to 3 and claim 10 to claim 15. The method for applying the coating material according to. 31. In the rotating step, the second rotation speed is rotated as a rotation speed at which gravity and centrifugal force applied to the coating material on the curved surface portion are balanced. The coating material coating method according to claim 3. 32. In the rotating step, the coating material is spin-coated as a first viscosity in which gravity and centrifugal force applied to the coating material on the curved surface portion are balanced. Item 4. The method for applying the coating material according to any one of items 3. 33. The base material to be coated on the peripheral surface portion,
A peripheral flat surface portion formed around the curved surface portion, so that the coating material gently flows down, a peripheral curved surface portion formed in a boundary region between the peripheral flat surface portion and the curved surface portion,
The coating material coating method according to any one of claims 1 to 32, further comprising: 34. The base material to be coated has a film thickness correcting concave-convex portion for correcting a film thickness after coating of a coating material, at a boundary region position between the peripheral surface portion and the curved surface portion. Item 33. A method for applying a coating material according to Item 33. 35. The curved surface portion is an effective curved surface portion from a center of a top portion to which the coating material to be flowed down adheres to a predetermined effective diameter required to have a substantially uniform film thickness distribution after coating the coating material. And the first radius of the curved surface portion is formed to be 1 to 10 times the second radius of the curved surface forming the peripheral curved surface portion, and the inclination of the tangent line of the second radius is substantially zero. 35. The boundary area position between the peripheral flat surface portion and the peripheral curved surface portion is formed at a position separated from at least twice the effective diameter of the effective curved surface portion. How to apply the coating material. 36. The distance from the center of rotation of the curved surface portion to the peripheral edge of the peripheral surface portion is set to 4 times or less the radius of the curved surface portion, according to any one of claims 33 to 35. The method for applying a coating material according to item. 37. The coating material coating method according to claim 4, wherein the rotating step rotates while pulling up the substrate to be coated on which the coating material has been coated by the coating step. 38. The coating material coating method according to claim 4, wherein the rotating step is performed after pulling up the substrate to be coated on which the coating material is coated by the coating step. 39. A coating material coating method for rotating a coating substrate to which a coating material is applied to coat the coating material on the coating substrate having at least one curved surface, A step of forming a curved surface portion having a surface roughness equal to or less than a first roughness on at least one surface of the base material; and the curved surface of the coating base material while rotating the coating base material. And a coating step of flowing the coating material down to the top of each part. 40. The coating material coating method according to claim 39, wherein the first roughness is 20 nm or less. 41. The method according to claim 39 or 40, wherein the step of forming the substrate to be coated is performed by cutting.
The method for applying the coating material according to. 42. The coating material coating method according to claim 41, wherein the cutting is performed while controlling the temperature. 43. The coating material coating method according to claim 41 or 42, wherein the cutting is performed by processing a shape with diamond. 44. A polishing step of polishing the curved surface portion is included between the forming step of the substrate to be coated and the coating step, and in the polishing step, the tool mark is polished until the rainbow is no longer visible. The coating material coating method according to claim 39. 45. A curved surface portion which is formed on at least one surface and on which a coating material is spin-coated, and the coating material is directed toward the periphery from the top portion of the curved surface portion while maintaining a substantially uniform film thickness due to the spin coating. And a peripheral surface portion formed so as to smoothly flow down according to the above, wherein the distance from the rotation center of the curved surface portion to the peripheral end of the peripheral surface portion is formed to be 4 times or less the radius of the curved surface portion. The base material to be coated. 46. A curved surface portion which is formed on at least one surface and on which a coating material is spin-coated, and the coating material is directed toward the periphery from the top portion of the curved surface portion while maintaining a substantially uniform film thickness with the spin coating. And a peripheral surface portion formed so as to smoothly flow down according to the above, and a film thickness correction uneven portion for correcting the film thickness after coating the coating material at the boundary region position between the peripheral surface portion and the curved surface portion. A substrate to be coated, which is formed. 47. The peripheral surface portion is formed in a boundary area between the peripheral flat surface portion and the curved surface portion so that the coating material smoothly flows down and the peripheral flat surface portion formed around the curved surface portion. The formed peripheral curved surface portion is included, and the film thickness correcting concave-convex portion is formed at a boundary region position between the peripheral curved surface portion and the curved surface portion.
The coated substrate according to item 6. 48. The unevenness portion formed at the boundary position of the first layer after coating with the coating material is absorbed by the unevenness portion for correcting the film thickness, according to claim 46. Coating base material. 49. The unevenness for all layers after coating the coating material is absorbed by the unevenness portion for correcting the film thickness when the coating material is coated a plurality of times. Base material to be coated. 50. The curved surface portion is an effective curved surface portion from a top center to which the coating material to be flowed down adheres to a predetermined effective diameter required to have a substantially uniform film thickness distribution after coating the coating material. The first radius of the curved surface portion is formed to be approximately 1 to 10 times the second radius of the curved surface forming the peripheral curved surface portion, and the inclination of the tangent line of the second radius is approximately The boundary area position between the peripheral flat surface portion and the peripheral curved surface portion which becomes zero is formed at a position separated from at least approximately twice the effective diameter of the effective curved surface portion. Coating base material. 51. The base material to be coated according to claim 50, wherein the unevenness portion for correcting the film thickness absorbs a non-uniform portion according to a film thickness distribution characteristic at the boundary region position. 52. The surface roughness of the curved surface portion is 50 nm or less, 43 to 45,
The coated substrate according to claim 48. 53. The surface roughness of the curved surface portion is set to 20 nm or less, 43 to 45,
The coated substrate according to claim 48. 54. The base material to be coated according to claim 43, wherein the base material to be coated is formed of a resin. 55. A curved surface portion formed on at least one surface, a peripheral flat surface portion formed around the curved surface portion, and a coating material which is continuously flown down to the top of the curved surface portion with rotation are substantially uniform. In order to smoothly flow down from the top to the periphery of the curved surface while maintaining a uniform film thickness,
A method for manufacturing a coated base material, comprising: a peripheral curved surface portion formed at a boundary region position between the peripheral flat surface portion and the curved surface portion; Processing is performed by forming a film thickness correction uneven portion for correcting the film thickness after coating the coating material on the boundary position with the curved surface portion based on predetermined reference shape data of the film thickness correction uneven portion. A method for producing a base material to be coated, comprising: 56. The reference shape data of the unevenness portion for correcting the film thickness is obtained by measuring the film thickness at each radial position of the coating material on a plurality of base materials to be coated after coating the coating material, The step of calculating the amount of displacement of, and the step of calculating the average value of the amount of displacement of the plurality of substrates to be coated,
56. The method for producing a base material to be coated according to claim 55, wherein 57. The manufacturing of a base material to be coated according to claim 56, wherein the film thickness at each radial position of the coating material is the film thickness of the first layer after coating the coating material. Method. 58. The film thickness at each radial position of the coating material is a film thickness of all layers after coating the coating material when the coating material is applied a plurality of times. The method for producing a base material to be coated according to. 59. The film thickness as the reference is an average film thickness of the coating material in a range within a distance of approximately 1.8 mm from a central portion of the substrate to be coated.
59. The method for manufacturing a base material to be coated according to claim 58. 60. A holding member for holding and rotating the base material to be coated, a rotation driving means for rotationally driving the holding member in a state where the center of rotation of the base material to be coated is substantially aligned, and the coating material. A coating material coating device for coating the coating material, and a control means for controlling the coating amount from the coating material coating means based on the number of revolutions by the rotation driving means. 61. When the coating material is continuously flowed down onto the coating substrate, the coating substrate is rotated at a predetermined first rotation speed, and after the coating material is coated, the coating material is coated. It has a rotation speed control means for controlling to rotate the coating base material at a second rotation speed that is higher than the first rotation speed, and the control means supplies or does not supply the coating material by the coating material coating means. 7. The first and second rotational speeds are controlled by the rotational speed control means in accordance with the above.
The coating material coating device according to item 0. 62. The coating material coating device according to claim 61, wherein the rotation speed control means controls the first rotation speed to fall within a range of 200 to 700 rpm. 63. The rotation speed control means controls the second rotation speed so as to rotate as a rotation speed at which gravity applied to the coating material on the curved surface portion and centrifugal force are balanced. The coating material coating device according to claim 61. 64. The coating material coating device according to claim 63, wherein the rotation speed control means controls the second rotation speed to be near 700 rpm. 65. A viscosity control means for adjusting and controlling the viscosity of the coating material supplied to the coating material coating means is provided, wherein the control means controls the number of revolutions by the rotation driving means and the coating amount of the coating material. The coating material coating device according to claim 60, wherein the viscosity is controlled based on the above. 66. The viscosity control unit controls the viscosity of the coating material to be a first viscosity at which gravity and centrifugal force applied to the coating material on the curved surface portion are balanced. The coating material coating device according to claim 65. 67. The coating material coating device according to claim 66, wherein the viscosity control unit controls the first viscosity to be approximately 150 (mPa · S) or less. 68. A coating material supply time control means for adjusting and controlling a supply time of the coating material supplied by the coating material coating means, wherein the control means continuously applies the coating material. The coating material coating device according to claim 60, wherein coating is performed by controlling the supply time so that the coating material is supplied. 69. Further comprising: an elevating means for raising and lowering the holding member; and a gravity control means for controlling the elevating and lowering by the elevating means while rotating the holding member to control gravity acting on the coating material. The coating material coating device according to claim 60, wherein: 70. A vertically inverting means for vertically inverting the holding member, a fixing means for fixing the base material to be coated to the holding member, and a base material to be coated held by the holding member is dipped in a coating material. And a solution tank for controlling the top surface of the substrate to be coated downward by the upside-down device while fixing the substrate to be coated to the holding member by the fixing device. The solution tank is impregnated in this state, and then the substrate to be coated immersed in the coating material is controlled so as to be raised while being rotated with the top facing downward. Item 60. The coating material coating device according to Item 60. 71. The holding member according to claim 60, wherein the holding member includes a first direction restricting portion that restricts a first direction in which a centrifugal force generated by the rotation of the substrate to be coated acts. Coating material coating device. 72. The coating according to claim 71, wherein the holding member has a concave portion on which the substrate to be coated is placed, and the first direction restricting portion is the side wall of the concave portion. Material coating device.