JP2003031476A - Resist film, its formation method and apparatus thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist film formation method for applying resist with uniform film thickness, a resist film formation apparatus, and a resist film. SOLUTION: A resist film formation apparatus 1 drops resist onto a still or rotating substrate by a spin coater 10, rotates the substrate for diffusing the resist onto the surface of the substrate by centrifugal force to form a resist layer of nearly uniform film thickness, vertically leaves resist 50 applied onto a substrate 40 as it is in an enclosure 20 for a fixed time, and gradually substitutes gas in the enclosure 20 for outdoor air. Therefore, vapor of a solvent evaporating from the resist is saturated in the enclosure 20, the drying of the resist in the enclosure 20 is suppressed, the resist is fluidized for making the surface flat, and at the same time, the vapor pressure of the solvent in the enclosure 20 is dropped gradually for drying the entire resist film uniformly after the surface becomes flat, thus preventing roughness on the surface of the resist, and hence forming a flat resist film without roughness on the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist film forming method, a resist film forming apparatus, and a resist film, and more specifically, a resist for applying a resist having a uniform film thickness used for producing micromachines, microlenses, and the like. The present invention relates to a film forming method, a resist film forming apparatus, and a resist film.

[0002]

2. Description of the Related Art Photolithography technology has been developed mainly in the field of semiconductors, but recently, it is also used in micromachining and the like, and the film thickness of the resist used and the underlying substrate are used. Various materials and shapes are being used.

In photolithography, in order to accurately transfer a pattern, it is necessary that the resist film is evenly and evenly applied. However, when the resist film has a thickness of several tens of um, When the substrate has a large step, it is difficult to apply the resist film uniformly.

Specifically, when a resist film is applied thickly, even if the film thickness is uniform immediately after spin coating, it takes a long time to dry, so that the film thickness may fluctuate greatly due to unevenness of drying or the resist surface There is a case where a tortoiseshell pattern is generated on the surface due to the difference in the drying speed inside and the shrinkage due to drying. Further, when spin coating is performed on a substrate having a high step, the center side and the peripheral side of the step have an asymmetric film thickness, or radial unevenness occurs from a pattern break.

Therefore, the step of applying the solvent of the coating solution onto one surface of the substrate which has been conventionally rotated or stopped, and the substrate coated with the solvent are rotated at a first rotation speed to remove the solvent from the substrate. A step of diffusing over the entire surface, and a predetermined amount of the coating liquid on the substantially central portion of the substrate by rotating the substrate at a second rotation speed and diffusing over the entire surface of the substrate to form a coating film. A coating film forming method having a step of forming a resist is proposed, and in this proposal, when the resist is spread on the surface of the substrate while rotating the substrate, a saturated atmosphere of the solvent is applied to the periphery of the substrate to form the resist. A method of preventing drying and avoiding coating unevenness has also been proposed (JP-A-7-32099).
No. 9).

Further, conventionally, means for holding the semiconductor wafer horizontally, means for dropping the resist on the central portion of the surface of the semiconductor wafer, means for rotating the means for holding the semiconductor wafer together with the semiconductor wafer, A resist coating apparatus is proposed, which comprises means for surrounding the semiconductor wafer, and the means for surrounding the semiconductor wafer rotates with the semiconductor wafer (Japanese Patent Laid-Open No. 6-260404).
(See the official gazette).

In other words, this conventional resist coating apparatus hermetically seals the substrate using a cup and a lid that surrounds the periphery of the wafer in order to suppress the scattering of the resist, and rotates them together with the substrate to rotate the periphery of the wafer. Airflow control and resist surface drying are prevented, and a flat surface is obtained.

Further, conventionally, a method of applying a photoresist, which includes a step of applying a liquid photoresist to a substrate to obtain a photoresist film, and a step of drying the obtained photoresist film for a predetermined time in a reduced pressure atmosphere. Has been proposed (see Japanese Patent Laid-Open No. 8-194316).

That is, in this conventional photoresist coating method, after the resist is spread and spread on the substrate by a spin coater, the substrate is put in a vacuum chamber and dried under reduced pressure. Prevents uneven drying that occurs between.

[0010]

In the technique described in the above publication, spin coating is performed in a solvent atmosphere of a resist to prevent unevenness due to drying of the surface, and after spin coating, the substrate is put in a decompression chamber, The resist is dried under reduced pressure.

However, in the method of rotating in a solvent atmosphere, surface drying during rotation can be avoided, but film thickness fluctuation cannot be avoided when the resist is dried at a high temperature, and in the drying method using a decompression chamber, Although it is possible to prevent the resist from flowing before the high temperature drying, there is a possibility that the surface is roughened or the resist is deteriorated. further,
The method of spin coating has a problem that the resist film thickness becomes asymmetric due to the step.

Therefore, the present invention provides a resist film forming method and a resist film forming method capable of forming a flat resist film without surface roughening even when the resist film is very thick or the base has a large step. An object is to provide a film forming apparatus and a resist film.

Specifically, in the invention according to claim 1, the resist is dropped on the substrate which is stopped or rotated, the substrate is rotated, and the resist is diffused to the surface of the substrate by a centrifugal force, so that the resist is deposited on the substrate. When a resist layer having a substantially uniform film thickness is formed and the resist layer on the substrate is heated and dried to form a resist film, the substrate coated with the resist is left in a sealed container for a certain period of time, By gradually replacing the gas inside with the outside air, the substrate is placed in a closed container immediately after the resist is applied, and the solvent vapor that evaporates from the resist is saturated in the closed container. The drying is suppressed, the resist flows, the surface is flattened, and after the surface is flattened, the vapor pressure of the solvent in the container is gradually reduced to uniformly dry the entire resist film,
An object of the present invention is to provide a resist film forming method capable of preventing a surface roughness of a resist and accurately forming a flat resist film without surface roughness even on a resist having a large film thickness or a substrate having a step. .

According to a second aspect of the present invention, after the substrate is taken out of the container, the resist on the outer peripheral portion of the substrate is removed, so that even if a thick film resist is used, the resist on the outer peripheral portion is removed and the surface is roughened. It is an object of the present invention to provide a resist film forming method capable of accurately forming a flat resist film without defects.

According to a third aspect of the present invention, the resist is dropped onto the stopped or rotating substrate, the substrate is rotated, and the resist is diffused onto the surface of the substrate by centrifugal force, so that a substantially uniform film thickness is formed on the substrate. Forming a resist layer of, when forming a resist film by heating and drying the resist layer on the substrate, the substrate coated with the resist is allowed to stand in the closed container means for a certain time, and the gas in the closed container means By gradually replacing the outside air, the substrate is put in the closed container means immediately after the resist is applied, and the vapor of the solvent evaporated from the resist is saturated in the closed container means, so that the resist in the closed container means While suppressing the drying, the resist flows and flattens the surface, and after flattening, the vapor pressure of the solvent in the closed container means is gradually reduced to uniformly dry the entire resist film. An object of the present invention is to provide a resist film forming apparatus capable of preventing the surface of a resist from becoming rough and accurately forming a flat resist film without surface roughening even on a thick resist or a substrate having a step. .

According to a fourth aspect of the present invention, in the closed container means,
By providing an opening for replacing the inside gas with the outside air, the atmosphere inside the substrate sealing means can be easily controlled, and the entire resist film can be dried more easily and uniformly, so that there is a thick resist film or a step. Also for the board
An object of the present invention is to provide a resist film forming apparatus capable of forming a flat resist film with further less surface roughness with higher accuracy.

According to a fifth aspect of the present invention, in the closed container means,
By providing a substrate holding part that holds the substrate in a state where the surface of the substrate is horizontal, it is possible to prevent the resist film thickness from being deviated due to the inclination of the substrate, and for a thick resist film or a substrate with a step Even so, it is an object of the present invention to provide a resist film forming apparatus capable of forming a flat resist film with less surface roughness more accurately.

According to a sixth aspect of the present invention, the substrate holding portion has a warp correction function for correcting the warp of the substrate, so that a flat resist film is formed even on a substrate having a warp. An object of the present invention is to provide a resist film forming apparatus capable of forming a flat resist film with further less surface roughness with higher accuracy.

According to a seventh aspect of the present invention, the substrate holding portion is provided with a flat holder and a vacuum suction mechanism that suctions the substrate onto the holder by vacuum suction to bring the substrate into close contact, and the flat holder holds the substrate. By adjusting the warp of the substrate by closely contacting it, a flat resist film can be appropriately and easily formed even on a substrate having a warp, and a flat resist film with further less surface roughness can be formed. It is an object of the present invention to provide a resist film forming apparatus that can be formed with higher accuracy.

According to an eighth aspect of the present invention, the substrate holding portion is provided with a flat holder and an electrostatic attraction mechanism for electrostatically attracting the substrate to the holder and bringing the substrate into close contact with the holder. By making the substrate adhere to correct the warp of the substrate, a flat resist film can be appropriately and easily formed even on a substrate having a warp, and a flat resist film with further less surface roughness. It is an object of the present invention to provide a resist film forming apparatus capable of forming a film with even higher accuracy.

According to a ninth aspect of the present invention, there is provided a resist film formed by dropping a resist on a substrate, the resist film forming method according to the first or second aspect, or any one of the third to eighth aspects. By forming with the resist film forming apparatus described in 1), a flat resist film can be formed appropriately and easily even on a substrate having a warp, and a flat resist film without surface roughness can be accurately formed, It is an object of the present invention to provide a resist film that can improve the yield when forming a three-dimensional resist pattern or patterning on a substrate with steps.

[0022]

According to a first aspect of the present invention, there is provided a resist film forming method, wherein a resist is dropped onto a stopped or rotating substrate, the substrate is rotated, and the resist is diffused on the surface of the substrate by centrifugal force. In the resist film forming method, a resist coating step of forming a resist layer having a substantially uniform film thickness on the substrate and a drying step of heating and drying the resist layer on the substrate are performed. The above object is achieved by including a standing step of leaving the formed substrate in a sealed container for a certain period of time and a gas replacement step of gradually replacing the gas in the container with the outside air.

According to the above construction, the resist is dropped onto the stopped or rotating substrate, the substrate is rotated, and the resist is diffused on the surface of the substrate by centrifugal force, so that the resist having a substantially uniform film thickness is formed on the substrate. When forming a layer and heating and drying the resist layer on the substrate to form a resist film, the substrate coated with the resist is left in a sealed container for a certain period of time, and the gas and the outside air in the container are gradually increased. Therefore, the substrate is placed in a closed container immediately after applying the resist, and the vapor of the solvent evaporated from the resist is saturated in the closed container, whereby the drying of the resist in the container can be suppressed. The resist flows and the surface can be flattened, and after flattening, the vapor pressure of the solvent in the container is gradually reduced to evenly dry the entire resist film and Le can be prevented, even for a substrate with a thick resist and the step of film thickness, no rough surface a flat resist film can be accurately formed.

In this case, for example, as described in claim 2, the resist film forming method includes a removing step of removing the resist on the outer peripheral portion of the substrate after taking out the substrate from the container. Good.

According to the above construction, after removing the substrate from the container, the resist on the outer peripheral portion of the substrate is removed.
Even when a thick film resist is used, the resist on the outer peripheral portion can be removed, and a flat resist film without surface roughness can be formed accurately.

According to a third aspect of the present invention, there is provided a resist film forming apparatus in which a resist dropping means for dropping a resist on a stopped or rotating substrate and a substrate for rotating the substrate to centrifuge the dropped resist. Substrate rotating means for diffusing on the surface to form a resist layer having a substantially uniform film thickness on the substrate, closed container means for leaving the substrate on which the resist layer is formed in a closed state, and inside the closed container means By providing a gas replacement means for gradually replacing the gas with the outside air, and a drying means for heating and drying the resist layer on the substrate after the gas replacement by the gas replacement means, the above object is achieved. There is.

According to the above construction, the resist is dropped onto the stopped or rotating substrate, the substrate is rotated, and the resist is diffused onto the surface of the substrate by centrifugal force, so that the resist having a substantially uniform film thickness is formed on the substrate. When forming a layer and forming a resist film by heating and drying the resist layer on the substrate, the substrate coated with the resist is left in the closed container means for a certain period of time, and the gas in the closed container means and the outside air are removed. Since it is gradually replaced, the substrate is put in the closed container means immediately after the resist is applied, and the vapor of the solvent evaporated from the resist is saturated in the closed container means, thereby suppressing the drying of the resist in the closed container means. And the resist can flow to flatten the surface, and after flattening,
By gradually reducing the vapor pressure of the solvent in the closed container means,
By uniformly drying the entire resist film, it is possible to prevent the surface of the resist from becoming rough, and it is possible to accurately form a flat resist film without surface roughness even on a resist having a large film thickness or a substrate with steps. it can.

In this case, for example, as described in claim 4, the closed container means may be provided with an opening for replacing the internal gas with the external air.

According to the above construction, since the closed container means is provided with the opening for replacing the internal gas with the outside air, the atmosphere inside the substrate sealing means can be easily controlled, and the resist film is simple and simple. By drying the whole more uniformly, even for thick resists and substrates with steps,
It is possible to more accurately form a flat resist film with less surface roughness.

Further, for example, as described in claim 5, the closed container means may be provided with a substrate holding portion for holding the substrate in a state where the surface of the substrate is horizontal.

According to the above construction, the closed container means is provided with the substrate holding portion for holding the substrate in a state where the surface of the substrate is horizontal, so that the resist film thickness is biased due to the inclination of the substrate. Even if a resist having a large film thickness or a substrate having a step is prevented, a flat resist film having less surface roughness can be formed more accurately.

Further, for example, as described in claim 6, the substrate holding portion may have a warp correction function for correcting the warp of the substrate.

According to the above structure, since the substrate holding portion has a warp correction function for correcting the warp of the substrate, a flat resist film can be formed even on a substrate having a warp. Therefore, it is possible to form a flat resist film with less surface roughness more accurately.

Further, for example, as described in claim 7, the substrate holding portion includes a flat holder, and a vacuum suction mechanism for vacuum-sucking and closely adhering the substrate onto the holder.
May be provided, and the warp of the substrate may be corrected by bringing the substrate into close contact with the flat holder.

According to the above structure, the substrate holding section is provided with the flat holder and the vacuum suction mechanism for vacuum-sucking and adhering the substrate onto the holder, and the substrate is adhered to the flat holder. Since the warp of the substrate is corrected by using the method described above, a flat resist film can be appropriately and easily formed even on a substrate having a warp, and a flat resist film with further less surface roughness can be formed. It can be formed more accurately.

Further, for example, as described in claim 8, the substrate holding part includes a flat holder, and an electrostatic adsorption mechanism for electrostatically adhering the substrate onto the holder to bring the substrate into close contact.
May be provided, and the warp of the substrate may be corrected by bringing the substrate into close contact with the flat holder.

According to the above structure, the substrate holding portion is provided with the flat holder and the electrostatic adsorption mechanism for electrostatically adhering the substrate onto the holder to bring the substrate into close contact, and the substrate is placed on the flat holder. Since the warp of the substrate is corrected by closely contacting it, a flat resist film can be appropriately and easily formed even on a substrate having a warp, and a flat resist film with further less surface roughness. Can be formed more accurately.

The resist film of the invention according to claim 9 is a resist film formed by dropping a resist on a substrate, and the resist film forming method according to claim 1 or 2 or claim 3 The above object is achieved by forming with the resist film forming apparatus according to any one of items 8.

According to the above configuration, the resist film formed by dropping the resist on the substrate is the resist film forming method according to claim 1 or 2, or any one of claims 3 to 8. Since it is formed by the resist film forming apparatus of, it is possible to appropriately and easily form a flat resist film even on a substrate having a warp, and to form a flat resist film without surface roughness with high precision. As a result, it is possible to improve the yield when forming a three-dimensional resist pattern or patterning on a stepped substrate.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The embodiments described below are preferred embodiments of the present invention, and therefore have various technically preferable limitations. However, the scope of the present invention refers to the present invention particularly in the following description. Unless otherwise stated, the present invention is not limited to these embodiments.

1 to 8 are views showing an embodiment of a resist film forming method, a resist film forming apparatus and a resist film of the present invention, and FIG. 1 is a resist film forming method and a resist film of the present invention. It is a schematic structure figure of a resist film forming device to which an embodiment of a forming device and a resist film is applied.

In FIG. 1, the resist film forming apparatus 1 is
A spin coater 10, a closed container 20, a hot plate container 30 and the like are provided.

The spin coater (resist dropping means, substrate rotating means) 10 includes a motor 11, a substrate holder 12 connected to the shaft of the motor 11, and two dispensers 13.
14 and the like, and an air controller (not shown) for controlling the atmosphere in the spin coater 10, and the like. The substrate 40 mounted on the motor 11 (see FIG.
Resist).

The closed container (closed container means) 20 is a container for closing the substrate 40 coated with the resist,
The substrate holding stage 21 and an outside air intake port (gas replacing means, opening) 2 for introducing outside air into the closed container 20.
2 and an exhaust port (gas replacement means, opening) 23 for discharging the gas in the closed container 20. In addition,
The closed container 20 may include a carrier device for carrying the substrate 40, a device for forming a resist adhesion layer on the substrate 40 before resist coating, and the like.

The hot plate container (drying means) 30 is
The substrate 40 containing the hot plate 31 and having the resist film formed thereon is baked to dry the resist film in a state suitable for exposure.

Next, a resist film forming process using the resist film forming apparatus 1 will be described with reference to FIGS. 2 to 7.

First, as shown in FIG. 2, the substrate 40, which has been surface-treated to improve the adhesiveness of the resist by HMDS (hexamethyldisilazane) treatment, is held by the substrate holder 12 of the spin coater 10. The resist 50 is dropped on the substrate 40 while the motor 11 is stationary or rotated at a low speed (about 1000 rpm or less). And the substrate 4
After the resist 50 is sufficiently dropped over the entire surface of the substrate 0, the resist 50 is spread over the entire surface of the substrate 40 by the centrifugal force of the rotation of the substrate 40 as shown in FIG. A resist coating step of rotating 11 is performed.

At this time, the unnecessary resist 50 is the substrate 4
It is shaken off of the substrate 40 by the centrifugal force of 0 rotation,
However, since the resist 50 remains thick on the outer peripheral portion of the substrate 40, the resist 50 around the peripheral part may be removed by spinning at high speed for several seconds. At this stage, the surface of the substrate 40 does not need to be completely flat as long as the resist 50 in an amount necessary to form the target film thickness remains on the substrate 40. Further, at this point, it is necessary to prevent the surface of the resist 50 from drying, and therefore, when the unnecessary resist 50 is removed, the rotation of the motor 11 is immediately stopped to shorten the processing time, It is desirable that the atmosphere around the substrate 40 be a saturated atmosphere of the resist solvent.

The resist 50 is applied to the substrate 40 as described above.
After the application, as shown in FIG. 4, the substrate 40 is quickly moved into the closed container 20, and a standing step is performed in which it is left for a certain period of time. At this time, the inside of the closed container 20 becomes a saturated atmosphere of the solvent due to the solvent of the resist 50 evaporated from the surface of the substrate 40, so that the resist 50 flows on the substrate 40 without being dried. Further, the substrate 40 is horizontally held on the substrate holding stage 21 in the closed container 20,
The surface of the substrate 40 is in a state without significant warpage or undulation. If the substrate 40 has a swell or a warp,
As the substrate holding stage (holder) 21 in the hermetic container 20, a substrate forcibly flattening the substrate 4 by vacuum suction or electrostatic suction is used to provide a warp correction function. In such a state, the surface of the substrate 40 becomes flat in about several minutes, although it depends on the viscosity and the film thickness of the resist 50.

Next, as shown in FIG. 5, the outside air intake 22 of the closed container 20 is opened to reduce the concentration of the resist solvent atmosphere inside, and the resist 50 is dried to form the resist 5
A gas replacement step is performed so that 0 does not flow. In this case, by naturally diffusing the resist solvent vapor in the closed container 20 from the outside air intake port 22, the concentration of the resist solvent vapor in the closed container 20 is gradually reduced and the resist 50 is slowly dried. At this time, the outside air may be forcibly taken into the closed container 20 and the atmosphere inside the closed container 20 may be exhausted, but if the outside air is taken in too rapidly, unevenness in drying of the resist 50 may occur. Since the surface of the resist 50 may be uneven, the outside air is forcibly taken in so that the surface is not roughened.

When the outside air is taken into the closed container 20,
Since the air flow generated inside the closed container 20 also causes the surface roughness, the outside air intake port 22 is formed in a shape that does not easily generate the air flow inside the closed container 20.

In the above embodiment, the case where the outside air intake 22 is attached to the closed container 20 has been described, but the outside air intake port 22 may be adjusted depending on how the lid of the closed container 20 is opened.

Next, the substrate 40 is taken out from the closed container 20 and returned to the spin coater 10 as shown in FIG.
A removal process is performed to remove the resist 50 on the peripheral portion of the substrate 40 from the dispenser 14 using the resist solvent or the solvent 15 for cleaning the peripheral portion. That is, the resist 5
As shown in FIG. 5, 0 is a peripheral portion of the substrate 40, particularly,
In some cases, the edge of the resist 50 may rise near the edge, and when etching or other processing is performed after lithography, the edge is clamped to fix the substrate 40, so the resist 50 is removed. It is desirable to set it. Note that the peripheral portion of the resist 50 is not removed at the stage of making the resist 50 uniform by rotating the motor 11 in FIG. 3, because even if the peripheral portion of the resist 50 is removed at this stage, the resist 50 still flows. This is because the edges flow to the edges. Further, when the resist 50 of about 1 μm is applied to the flat substrate 40, the peripheral portion of the resist 50 is also removed at the same time in the stage of FIG. 3, but in this case, the resist 50 is rotated while rotating the motor 11. This is because the drying of the resist 50 is also performed at the same time, and when forming the thick resist 50, it is difficult to dry while rotating. Therefore, the peripheral portion of the resist 50 is removed at the stage of FIG.

Finally, as shown in FIG. 7, the substrate 40 from which the resist 50 in the peripheral portion has been removed is placed on the hot plate 31 in the hot plate container 30 and baked on the hot plate 31. Then, a drying step of drying the resist 50 to a state suitable for exposure is performed.

The resist film 50 thus formed
Is capable of flattening the surface even with the thick film resist 50, and is also manufactured in a manufacturing process sensitive to variations in the resist film thickness within the wafer, for example, a process of forming a three-dimensional resist pattern. The process yield can be improved. Further, even when the substrate 40 having a large unevenness of the base is exposed by using a stepper, it is possible to reduce the film thickness variation between the center side and the outer peripheral side of the substrate 40 in the base step portion. It is possible to reduce the dimensional variation between them.

As described above, the resist film forming method and the resist film forming apparatus 1 of the present embodiment are the same as the spin coater 1
The resist 50 coated on the substrate 40 at 0 is stored in the closed container 2
Within 0, it remains horizontal for a certain period of time.

Therefore, the flat resist film 50 can be formed even on the thick resist 50 which is likely to cause unevenness due to the fluidity of the resist 50 and the substrate 40 having a step on the base.

Further, in the resist film forming method and the resist film forming apparatus 1 of the present embodiment, the solvent evaporated from the resist 50 applied to the substrate 40 is used in order to make the inside of the closed container 20 a resist solvent atmosphere. There is.

Therefore, it is not necessary to add a device for making the solvent atmosphere, and by drying the flattened resist film 50 in a resist solvent atmosphere which is slightly thinner than the saturated state while still, the resist surface can be obtained. Roughness can be prevented.

As the airtight container 20 in which the air flow is not easily generated, the airtight container (airtight container means) 60 as shown in FIG. 8 can be used. The closed container 60 is divided by a partition wall 63 into a front chamber 61 whose inside is formed on the upper side and a main chamber 62 formed on the lower side, and the partition wall 63 divides the front chamber 61 and the main chamber 62. Opening 64
Are formed. The substrate holding stage 2 is provided in the main chamber 62.
1 is provided, and the substrate 40 coated with the resist 50 is introduced and placed on the substrate holding stage 21 from the wafer introduction port formed on the side surface of the main chamber 62. This wafer introduction port is closed by a lid 65, and the lid 65 is
It is opened when the substrate 40 is inserted and when it is taken out. In the closed container 60, an intake port (gas replacement means, opening) 66 is opened at the center of the upper portion of the front chamber 61, and at the lower portion of the main chamber 62, exhaust gas for discharging the gas in the main chamber 62 to the outside. A mouth (gas replacement means, opening) 67 is formed.

In this closed container 60, the air introduced from the intake port 66 is first introduced into the front chamber 61, and the air introduced into the front chamber 61 is evenly distributed through the openings 64 provided in the partition wall 63. Substrate 40 in main room 62 in which 40 is placed
The gas containing the vapor of the resist solvent supplied to the above,
It is discharged from the exhaust port 67. If you do not want to exhaust the exhaust containing the vapor of the resist solvent to the outside, use such a closed container 6
Exhaust can be managed more easily by making the shape 0 and exhausting.

Although the invention made by the present inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

[0063]

According to the resist film forming method of the first aspect of the present invention, the resist is dropped onto the stopped or rotating substrate, the substrate is rotated, and the resist is diffused onto the substrate surface by centrifugal force. To form a resist layer with a substantially uniform thickness on the substrate and heat-dry the resist layer on the substrate to form a resist film, leave the substrate coated with the resist in a sealed container for a certain period of time. Then, since the gas in the container is gradually replaced with the outside air, the substrate is put into the closed container immediately after the resist is applied, and the vapor of the solvent evaporated from the resist is saturated in the closed container. The drying of the resist can be suppressed, the resist can flow, and the surface can be flattened, and after becoming flat, by gradually lowering the vapor pressure of the solvent in the container,
By uniformly drying the entire resist film, it is possible to prevent the surface of the resist from becoming rough, and it is possible to accurately form a flat resist film without surface roughness even on a resist having a large film thickness or a substrate with steps. it can.

According to the resist film forming method of the second aspect of the present invention, after removing the substrate from the container, the resist on the outer peripheral portion of the substrate is removed. Therefore, even when a thick film resist is used, the resist on the outer peripheral portion is removed. Can be removed, and a flat resist film without surface roughness can be accurately formed.

According to the third aspect of the resist film forming apparatus of the present invention, the resist is dropped onto the stopped or rotating substrate, the substrate is rotated, and the resist is diffused to the surface of the substrate by centrifugal force. When a resist layer having a substantially uniform film thickness is formed on the resist layer and the resist layer on the substrate is heated and dried to form a resist film, the substrate coated with the resist is left to stand in a closed container means for a certain period of time. Since the gas in the closed container means is gradually replaced with the outside air, the substrate is put into the closed container means immediately after coating the resist, and the vapor of the solvent evaporated from the resist is saturated in the closed container means,
The drying of the resist in the closed container means can be suppressed, the resist can flow and the surface can be flattened, and after flattening, the vapor pressure of the solvent in the closed container means is gradually increased. By lowering it, it is possible to uniformly dry the entire resist film and prevent the surface of the resist from becoming rough. Even for a thick resist or a substrate with steps, a flat resist film with no surface roughness can be accurately formed. Can be formed.

According to the resist film forming apparatus of the fourth aspect of the present invention, since the closed container means is provided with the opening for replacing the internal gas with the outside air, the atmosphere inside the substrate sealing means can be easily controlled. It can be performed easily and more easily by drying the entire resist film more uniformly, and even with a thick resist or a stepped substrate, a resist film with less surface roughness and flatness can be formed more accurately. be able to.

According to the resist film forming apparatus of the fifth aspect of the present invention, since the hermetic container means is provided with the substrate holding portion for holding the substrate in a state where the surface of the substrate is horizontal,
It is possible to prevent the resist film thickness from becoming uneven due to the inclination of the substrate, and even with a thick resist film or a substrate with steps, a flat resist film with less surface roughness can be formed more accurately. can do.

According to the resist film forming apparatus of the sixth aspect of the present invention, since the substrate holding portion has a warp correction function for correcting the warp of the substrate, it is flat against a substrate having a warp. It is possible to form a uniform resist film, and it is possible to form a flat resist film with less surface roughness with higher accuracy.

According to the resist film forming apparatus of the seventh aspect of the present invention, the substrate holding part is provided with a flat holder and a vacuum suction mechanism for vacuum-sucking the substrate onto the holder to bring the substrate into close contact. Since the substrate is brought into close contact with a flat holder to correct the warp of the substrate, a flat resist film can be appropriately and easily formed even on a substrate having a warp, and the surface can be further improved. It is possible to more accurately form a flat resist film without roughness.

According to the resist film forming apparatus of the eighth aspect of the present invention, the substrate holding portion is provided with a flat holder and an electrostatic attraction mechanism for electrostatically attracting and closely adhering the substrate onto the holder. Since the substrate is brought into close contact with the flat holder to correct the warp of the substrate, a flat resist film can be appropriately and easily formed even on a substrate having a warp. It is possible to form a flat resist film with further less surface roughness more accurately.

According to the resist film of the invention described in claim 9, a resist film formed by dropping a resist on a substrate is used as the resist film forming method according to claim 1 or claim 3 or claim 3. Since the resist film is formed by the resist film forming apparatus according to any one of items 8, a flat resist film can be appropriately and easily formed even on a substrate having a warp, and a flat surface without surface roughness can be obtained. The yield can be improved when the resist film is formed with high accuracy to form a three-dimensional resist pattern or when patterning is performed on the stepped substrate.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a resist film forming apparatus to which an embodiment of a resist film forming method, a resist film forming apparatus, and a resist film of the present invention is applied.

FIG. 2 is a partially enlarged front view showing a state in which a resist is dropped and applied on a substrate by the spin coater of FIG.

FIG. 3 is a partially enlarged front view of a state in which the motor of the spin coater shown in FIG. 2 is rotated to spread the resist on the substrate over the entire substrate.

4 is an enlarged front view of the resist-coated substrate of FIG. 3 moved into the closed container of FIG.

FIG. 5 is an enlarged front view of a state in which outside air is introduced into the closed container of FIG. 4 and dried.

6 is an enlarged front view showing a state in which the dried resist of FIG. 5 is introduced into the spin coater of FIG. 1 to remove the peripheral portion of the resist.

7 is an enlarged front view of the state where the resist and the substrate of which the peripheral portion is removed in FIG. 6 is stored in the hot plate container of FIG. 1 and dried.

FIG. 8 is a front view of an example of a hermetically sealed container in which airflow is unlikely to occur.

[Explanation of symbols]

1 Resist film forming equipment 10 spin coater 11 motor 12 Board holder 13, 14 dispenser 20 airtight container 21 Substrate holding stage 22 Outside air intake 23 Exhaust port 30 hot plate containers 31 hot plate 40 substrates 50 resist 60 airtight container 61 front room 62 main room 63 partitions 64 openings 65 lid 66 Inlet 67 Exhaust port

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B05D 7/00 B05D 7/24 301Z 7/24 301 G03F 7/16 G03F 7/16 502 502 H01L 21/30 564D

Claims (9)

[Claims] 1. A resist for dropping a resist onto a stopped or rotating substrate, rotating the substrate, and diffusing the resist onto the surface of the substrate by centrifugal force to form a resist layer having a substantially uniform thickness on the substrate. A coating step, a drying step of heating and drying the resist layer on the substrate, in a method of forming a resist film, a step of leaving the substrate coated with the resist in the resist coating step in a sealed container for a certain time, ,
A method of forming a resist film, comprising: a gas replacement step of gradually replacing the gas in the container with the outside air. 2. The resist film forming method according to claim 1, further comprising a removing step of removing the resist on the outer peripheral portion of the substrate after taking out the substrate from the container. . 3. A resist dropping means for dropping a resist onto a stopped or rotating substrate, and rotating the substrate to diffuse the dropped resist onto the surface of the substrate by centrifugal force so that the resist is substantially uniform on the substrate. Substrate rotating means for forming a resist layer having a uniform thickness, closed container means for leaving the substrate on which the resist layer is formed in a closed state, and gas replacement means for gradually replacing the gas in the closed container means with the outside air. And a drying means for heating and drying the resist layer on the substrate after the gas is replaced by the gas replacement means. 4. The closed container means is provided with an opening for replacing the internal gas with the external air.
The described resist film forming apparatus. 5. The resist film formation according to claim 3 or 4, wherein the closed container means is provided with a substrate holding portion which holds the substrate in a state where the surface of the substrate is horizontal. apparatus. 6. The resist film forming apparatus according to claim 5, wherein the substrate holder has a warp correction function for correcting the warp of the substrate. 7. The substrate holding unit includes a flat holder and a vacuum suction mechanism for vacuum-sucking and adhering the substrate onto the holder, and the substrate is adhered to the flat holder to attach the substrate. 7. The resist film forming apparatus according to claim 6, wherein the warp of the resist film is corrected. 8. The substrate holding part includes a flat holder and an electrostatic attraction mechanism for electrostatically attracting and adhering the substrate onto the holder, and adhering the substrate to the flat holder. The resist film forming apparatus according to claim 6, wherein the warp of the substrate is corrected. 9. A resist film formed by dropping a resist on a substrate, wherein the resist film forming method according to claim 1 or 2 or the resist according to any one of claims 3 to 8. A resist film formed by a film forming apparatus.