JP2002280284A - Photomask housing device, photomask frame, photomask unit, projection aligner, method for projection alignment, and method of manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the service life of a pellicle film, and in addition, to more accurately and surely realize a fine resist pattern, without lowering treatment efficiency at the time of performing scanning projection alignment. SOLUTION: In a method, in which the image of a photomask pattern provided on a photomask is projected and exposed upon and on a surface to be exposed by irradiating the photomask with light from an exposure light source by means of a projection optical system, the image is projected and exposed upon the surface to be exposed by scanning the photomask, while the photomask is housed in a hermetically sealable enclosure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improved photomask structure, and also relates to a projection exposure apparatus, a projection exposure method and a semiconductor manufacturing method using the same. Further, as a specific application, in the production of a semiconductor integrated circuit or the like, when a circuit pattern is transferred, a scanning projection exposure apparatus and a photomask used in the apparatus that can suppress deformation of the pattern shape can be suppressed. It is about structure and use.

[0002]

2. Description of the Related Art FIG. 7 is a sectional view showing the structure of a photomask unit used as a photomask in a projection exposure apparatus. As shown in FIG. 7, the photomask substrate 1
Has a pellicle film 2, and a photomask pattern 3 is formed on the side covered by the pellicle film 2.
The pellicle film 2 is stretched on the frame 4 almost in parallel with the photomask pattern 3 in order to prevent foreign matter such as fine particles in the air from adhering to the photomask pattern 3. 8
Denotes a photomask substrate 1, a pellicle film 2, and a frame 4.
Indicates a space surrounded by. The photomask unit 100 includes the photomask substrate 1, the pellicle film 2, the photomask pattern 3, the frame 4, and the space 8.

FIG. 8 is a perspective view showing the structure of a conventional scanning projection exposure apparatus, FIG. 9 is a sectional view showing the structure of a projection exposure apparatus according to the prior application, and FIG. FIG. 4 is a diagram for explaining a state of the photomask storage device according to the present invention during scanning. As shown in FIG. 8, light from an exposure light source 18 (specifically, an oscillated F2 laser) transmits through a photomask unit 100 and a projection optical system 15 and is processed by a substrate 17 (specifically, a semiconductor wafer). An image of the photomask is formed on the image.

At this time, the exposure light source 18 irradiates the illumination area 14 of the photomask unit 100 from the rectangular opening 11A of the masking blade 11. On the other hand, as shown by the arrow in FIG. 8, the photomask unit 100 moves with the scanning of the support (scan stage) 12 in a direction perpendicular to the illumination area 14. Thereby, the entire photomask pattern 3 in the photomask unit 100 is irradiated, and the transfer of the photomask pattern is completed.

[0005] This scanning type projection exposure is more effective than the batch type projection exposure in which one chip is exposed in one shot.
The exposure field can be enlarged, and at the same time, the portion of the lens with less aberration can be effectively used. Therefore,
This is an important method for forming a finer resist pattern.

On the other hand, with the recent miniaturization of design rules in semiconductor integrated circuit patterns, the exposure wavelength has been shortened. At present, the light source of the exposure apparatus for circuit pattern transfer, which is currently mainstream, is a KrF excimer laser having a wavelength of 248 nm, followed by an ArF excimer laser having a wavelength of 193 nm. Next to the excimer laser is a vacuum ultraviolet F2 laser (wavelength: 157 nm).

By the way, since a laser having a short wavelength of 193 nm or shorter is absorbed by oxygen or moisture in the atmosphere, it is necessary to purge with an inert gas such as nitrogen at the time of projection exposure. In addition, since it is necessary to avoid adhesion of foreign matter on the photomask substrate, a pellicle is indispensable.

[Problems to be solved by the invention]

However, because of the high energy of the F2 laser, the pellicle film, especially the pellicle film made of an organic polymer, is easily destroyed by laser irradiation, and its life is longer than that of the current pellicle film. Very short. That is, the thickness of the pellicle film is as thin as 600 to 1000 nm, and the light resistance against irradiation with a short wavelength high energy laser such as F2 laser light is extremely low.

Further, in order to accurately and reliably realize a fine resist pattern, it is necessary to suppress a change in light transmittance due to generation of outgas or the like from a scanning component or the like.

SUMMARY OF THE INVENTION An object of the present invention is to provide a projection exposure method which solves the above problems, extends the life of a pellicle film, and accurately and reliably realizes a fine resist pattern. .

[0011]

According to a photomask storage device of the present invention, two opposing plates are made of a light transmissive material, and a photomask is stored and supported so as to oppose the two plates. And a scanning means for scanning the photomask inside the housing.

Further, in the photomask storage device of the present invention, the housing has an opening / closing part in a part thereof so that the photomask can be exchanged.

Further, in the photomask storage device of the present invention, the two opposite plates are arranged at an interval of 3 cm or less.

Further, in the photomask storage device according to the present invention, the scanning means can scan the photomask inside the housing in a non-contact state.

Further, in the photomask storage device of the present invention, the scanning means can apply a driving force for scanning the support table from outside the housing without contacting the inside of the housing. Including the source.

Also, in the photomask storage device of the present invention, the two opposite plates are made of calcium fluoride, barium fluoride, or fluorine-added synthetic quartz,
It has a coating to suppress reflection.

Further, the photomask storage device of the present invention is the photomask storage device according to any one of claims 1 to 6, further comprising an interferometer for detecting a position of the photomask scanned inside the housing. It is a thing.

Next, the pellicle frame of the present invention holds an organic material pellicle film stretched at a predetermined interval so as to face the surface of the photomask, and to maintain a space between the photomask and the pellicle film. A frame to be sealed, having an opening for flowing a gas filled in a space closed by the photomask, the pellicle film, and the frame.

Further, in the pellicle frame according to the present invention, the opening is opened and closed in accordance with a scanning direction of the photomask.

Further, in the pellicle frame according to the present invention, the opening has a filter for adjusting a flow rate of a gas flowing through the space.

Further, in the pellicle frame according to the present invention, the opening is provided with a filter for preventing foreign matter from entering the space.

Further, in the pellicle frame of the present invention, the opening includes a pressure adjusting mechanism for adjusting a pressure in the space.

Further, in the pellicle frame according to the present invention, the pressure adjusting mechanism can adjust the pressure to be different depending on the scanning direction of the photomask.

Next, the photomask unit of the present invention comprises a photomask substrate, a pellicle film of an organic material opposed to the surface of the photomask substrate and stretched at a predetermined distance from the surface, In a photomask unit including a frame that holds a pellicle film and seals the space between the pellicle film and the photomask substrate, the pellicle frame according to any one of claims 8 to 13 is used as the frame.

Next, a projection exposure apparatus according to the present invention is a projection exposure apparatus having an exposure light source and an optical system for irradiating light to be emitted from the exposure light source and transmitted through a photomask to a surface to be exposed of a substrate to be processed. A photomask storage device according to any one of claims 1 to 7 is loaded.

According to a projection exposure apparatus of the present invention, in the projection exposure apparatus of claim 15, the photomask unit of claim 14 is housed in the photomask storage device.

Next, a projection exposure method according to the present invention includes an exposure light source, a photomask protected by a pellicle film, and a projection optical system, wherein a photomask pattern on the photomask is exposed to light from the exposure light source. In the method of projecting and exposing the image of the photomask pattern on the surface to be exposed by the projection optical system, the photomask is housed in a sealable housing, and scanned inside the housing, Projection exposure is performed.

In the projection exposure method according to the present invention, the photomask is scanned in a non-contact state with the inside of the housing together with the support for supporting the photomask.

Further, in the projection exposure method according to the present invention, a driving force for scanning the support table is applied from the outside of the housing without contacting the inside of the housing.

Further, in the projection exposure method according to the present invention, the photomask is scanned while a gas in a space surrounded by the photomask, the pellicle film, and the pellicle frame is allowed to flow.

Also, in the projection exposure method according to the present invention, the pellicle frame has an opening that opens in the scanning direction, thereby scanning the photomask while automatically flowing the gas in the space. It is.

In the projection exposure method according to the present invention, when the gas in the space flows, the photomask is scanned while adjusting the pressure in the space according to the scanning direction of the photomask. is there.

In the projection exposure method according to the present invention, the space is filled with an inert gas containing a predetermined amount of an active gas, and the projection exposure is performed.

Further, in the projection exposure method according to the present invention, the active gas is any one of oxygen, ozone, carbon dioxide, carbon monoxide, nitrogen oxides, or oxygen sulfur, or an organic gas containing oxygen. is there.

In the projection exposure method according to the present invention, the inert gas is any one of nitrogen, helium, and argon.

In the projection exposure method of the present invention, the scanning of the photomask is performed while detecting the position of the photomask inside the housing.

Next, a method of manufacturing a semiconductor device according to the present invention uses the projection exposure method according to any one of claims 17 to 26.

[0038]

Embodiments of the present invention will be described below with reference to the drawings. In each of the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will be simplified or omitted.

Embodiment 1 FIG. 1 is a cross-sectional view for explaining the structure of a photomask storage device that stores a photomask unit used in Embodiment 1 of the present invention.
FIG. 2 is a sectional view showing the structure of the projection exposure apparatus used in the first embodiment of the present invention. FIG. 3 is a diagram for explaining the concept of the operation of the scanning unit 9 for scanning the photomask storage device according to the first embodiment inside the housing, but the electromagnet 9B is located outside the housing. It is provided in.

In FIG. 1, 1 is a photomask substrate,
2 is a pellicle film, 3 is a photomask pattern, 4
Indicates a frame (or a beam), and 8 indicates a space and gas filled in the space.

A mask pattern 3 is formed on one surface of the photomask substrate 1. A pellicle film 2 is stretched on the frame 4 substantially in parallel with the mask pattern 3 at a predetermined interval (generally about 6 mm). Thus, the photomask pattern 3 is protected. Photomask substrate 1 and pellicle film 2
The frame 4 forms a closed space 8, and the space 8 is filled with a purge gas composed of an inert gas mixed with a predetermined amount of an active gas. The photomask unit 100 includes the photomask substrate 1, the pellicle film 2, the photomask pattern 3, the frame 4, and the space 8. In general, a fluorinated polymer or the like is used as the material of the pellicle film 2, and aluminum or the like is used as a material of the frame 4. However, it is not limited to this within the scope of the present invention.

5 is a photomask unit 100
5A and 5B are two opposing plates of the housing 5, which are an upper surface plate and a lower surface plate, respectively. The upper plate 5A and the lower plate 5B are made of a light transmissive material, and the distance between the two surfaces is preferably 3 cm.

The distance between the two surfaces is set to 3c in order to avoid a decrease in the exposure rate due to the active gas absorbing the exposure light.
m or less. However, it is not limited to this within the scope of the present invention. Further, as the light-transmitting material used for the two-sided plate, calcium fluoride, barium fluoride, synthetic quartz doped with fluorine, or the like is preferable, and a coating for suppressing reflection is preferably applied. It is not limited to this.

Reference numeral 6 denotes a support for fixing the photomask unit 100 accommodated in the inside 5C. In the first embodiment, the support 6 also has a function as an adjusting means. The photomask unit 100 includes an upper surface plate 5A and a lower surface plate 5
It is adjusted to be substantially parallel to B and fixed. As the adjusting means 6, for example, a piezo element may be used. The housing 5 has, for example, an opening / closing mechanism (not shown) such as a window that can be opened and closed on a side surface.
In addition, it can be freely attached and detached.

Reference numeral 9 denotes scanning means for scanning the photomask inside the housing, 9A denotes a permanent magnet, 9B denotes an electromagnet as a drive source, and the permanent magnet 9A denotes a support (adjustment means).
6, and the electromagnet 9 </ b> B is provided outside the housing 5. The permanent magnet 9A and the electromagnet 9B are linear motors. A scanning unit (electromagnet) 9 including a normal magnet 9A and an electromagnet 9B and using these as a driving motor is configured.

In FIG. 3, 10A is a reflector provided on two sides of the support, 10B is a light source, 10B
C indicates a light receiver, 10D indicates a half mirror, and 10E indicates a reference mirror. The light emitted from the light emitting source 10B is branched via the half mirror 10D, and one of the branched lights is reflected by the reflector 10A and enters the light receiver 10C.
The other is configured to reflect off the reference mirror 10E and enter the light receiver 10C.

Reflector 10A, light emitting source 10B, light receiver 10
C, including the half mirror 10D and the reference mirror 10E,
The interferometer 10 is configured so that the position of the photomask 100 during operation can be detected by the interferometer. Although the interferometer 10 is shown only on one side in the figure,
It is provided on two sides to detect the position in both the vertical and horizontal directions. However, it is not limited to the case of two aspects.

The photomask storage device 200 includes the housing 5, the support (adjustment means) 6, and the scanning means 9.

Further, in this specification, a photomask provided with a pellicle film is provided with a photomask unit, a support (adjustment means), a scanning means, etc., and a housing capable of accommodating the photomask unit therein is used as a photomask. It will be referred to as a mask storage device.

In FIG. 2, reference numeral 18 denotes an exposure light source, 11 denotes a masking blade, 15 denotes a projection optical system, and 16 denotes a table (wafer scan stage) on which a substrate 17 to be processed is placed. The projection exposure apparatus is loaded with a photomask storage device 200 containing a photomask unit 100 as a photomask. Substrate 17 to be processed
Is, for example, a semiconductor wafer, and the exposure light source 18 is, for example, an F2 laser.

Next, the operation of the projection exposure apparatus and the photomask storage apparatus when performing projection exposure using this projection exposure apparatus will be described.

As shown in FIG. 2, the photomask storage device 200 is mounted in an exposure device. Further, the photomask unit 100 confirms that there is no large foreign matter transferred to the substrate 17 on the glass surface of the photomask substrate 1 and the pellicle film 2, and then opens and closes the housing 5 (not shown). From the photomask storage device 200. After the photomask unit 100 is adjusted by the adjusting means (supporting table) 6 so that the position and inclination in the inside 5C are adjusted so as to be substantially parallel to the upper surface plate 5A and the lower surface plate 5B of the housing 5, the supporting table ( Adjusting means 6).

Exposure light (specifically, F2 laser light) emitted from the exposure light source 18 enters the projection optical system 15 via the photomask storage device 200, is converged by the projection optical system 15, and The exposed surface of the surface is exposed.

In FIG. 3, reference numeral 14 denotes an irradiation area for the photomask storage device. The arrow indicates the scanning direction, which is a direction perpendicular to the long side of the rectangular irradiation region 14.

During one exposure, the photomask device 200 irradiates only the irradiation area 14 of the exposure light emitted from the exposure light source, which is irradiated by the exposure light passing through the strip-shaped opening 11A of the masking blade 11. Can be When a current flows through the electromagnet 9B, the driving force in the direction of the arrow is given to the normal magnet 9A when the current flows through the electromagnet 9B. by this,
A support (adjustment means) with the inside 5C of the housing and the permanent magnet 9A
6 and photomask unit 10 provided therein
0 scans in the direction of the arrow. As a result, the entire surface of the mask pattern 3 of the photomask unit 100 fixed to the inside 5C of the housing is irradiated, and the transfer of the mask pattern to the substrate 17 to be processed is completed.

According to this, the permanent magnet 9A, the support 6 provided with the magnet 9A, and the photomask unit 100 are scanned in the inside 5C of the housing by the change in the magnetic field by the electromagnet 9B. Without the parts of
A driving force can be applied to the inside of the housing in a non-contact state. Furthermore, even inside the housing, scanning can be performed in a floating state, that is, in a state of not contacting the housing 5. Therefore, projection exposure can be performed without being affected by outgas generated due to contact of a scanning component or the like, and projection exposure can be performed efficiently by scanning a photomask at high speed.

In this embodiment, the principle of a linear motor is used as a drive source for the drive means 9 to scan the support base 6 and the photomask unit 100. However, the present invention is not limited to this.For example, a tire may be placed under a support and scanning may be performed by applying a force to rotate the tire from an external drive source, or a rail may be mounted under the support. Alternatively, the scanning may be performed by other means within the scope of the present invention, such as a method in which air is flown so that the support table is scanned in a floating state. In addition, in order to prevent the support table from blurring during scanning, it is desirable that there be a rail in the scanning direction such that the support table can be engaged and scanned. However, it is not limited to this.

During scanning, light is emitted from the light emitting source 10B provided inside the housing, and this light is transmitted to the half mirror 1
Branch at 0D. One of the branched lights is reflected on a reflecting plate 10A provided on the support 6 and reflected, and the reflected light is made incident on a light receiver 10C. The other branch light is reflected by the reference mirror 10E, and the reflected light is reflected by the light receiver 10C.
Incident on By measuring the two incident lights, the position of the photomask unit 100 can be detected, and thereby, scanning can be performed while confirming the position of the photomask unit 100. However, the present invention is not limited to this, and other means may be used within the scope of the present invention, or no such detecting means may be provided.

In the first embodiment, the above-mentioned purge gas is circulated through the gas supply port 7A and the gas recovery port 7B in the housing interior 5C. This is for exhausting outgas generated from a pellicle or the like.
However, the photomask storage device 200 has the gas supply port 7A.
Alternatively, without the gas recovery port 7B, after the inside of the housing 5C is filled with the above-described purge gas, projection exposure may be performed with the housing 5 sealed.

The space 8 in the photomask unit 100
The reason why the inside of the housing 5C is purged by using a purge gas composed of an inert gas mixed with an active gas is to extend the life of the pellicle film 2, particularly, the pellicle film made of an organic material.

The concentration of the active gas to be mixed is suitably in the range of 50 ppm to 10000 ppm. The higher the concentration of the active gas, the longer the life of the pellicle film. Thus, an appropriate concentration can be selected as needed. The range for achieving both the life of the pellicle film and the light transmittance is the above-described range.

As the inert gas described above, any one of nitrogen, argon and helium is suitable, but is not necessarily limited to these. Also,
The active gas mixed with the inert gas is preferably selected from any of oxygen, ozone, carbon dioxide, carbon monoxide, nitrogen oxides, sulfur oxides, and organic gas containing oxygen. However, it is not necessarily limited to these.

The description of the active gas and the inert gas in this embodiment also applies to other embodiments that follow. Therefore, the description is omitted each time.

Embodiment 2 FIG. 4 is a view showing a structure of a photomask unit used in Embodiment 2 of the present invention, and FIG. 4 (a) includes a partial cross-sectional view of the photomask unit. FIG. 3 is a top view showing the frame 4 in a cross section. FIG. 4B is a side view, and FIG.
It is a sectional view when (b) is cut in the AA 'direction. In FIG. 4, reference numeral 4A denotes an opening of the frame. Also, 4
B denotes a filter for preventing foreign matter from entering, and in this embodiment, also functions as a filter for adjusting the flow rate of gas. Further, the arrows indicate the scanning direction.

The openings 4A are provided on two of the four surfaces of the frame 4 perpendicular to the scanning direction of the photomask.
A filter 4B for preventing foreign matter from entering is stretched over the opening 4A. A frame 4 having an opening 4A, a foreign matter entry preventing filter (flow rate adjusting filter) 4B, a photomask substrate 1, a pellicle film 2, a photomask pattern 3, a space 8
Are included in the photomask unit 300.
The other parts are the same as in the first embodiment.
Description is omitted.

In this embodiment, the photomask unit 300 is housed in the photomask housing device 200. When the photomask unit 300 having this frame is scanned in the direction of the arrow in the interior 5C of the housing, the gas in the interior 5C of the housing also flows through the opening 4A into the space 8 and the space 8 is Purged with gas. At this time, the gas inside the housing 5C has passed through the foreign matter prevention filter (flow control filter) 4B, foreign matter in the gas is removed, and the amount of gas flowing into the space 8 is adjusted. ing.

In this way, even when outgassing occurs in the space 8 from the pellicle film or the like during the projection exposure,
By discharging the mixture, a fresh mixed gas is introduced, and a decrease in light transmittance can be suppressed.

Further, before the gas inside the housing flows into the space 8 of the photomask unit 300, it passes through a filter 4B for preventing foreign matter from entering (flow rate adjusting filter). Therefore, it is possible to prevent foreign matters from entering the space 8 and being transferred to the resist pattern during exposure. At the same time, since the amount of the gas flowing into the photomask unit 300 is adjusted, it is possible to prevent the gas from rapidly flowing into the space 8. Therefore, the pellicle film 2 is deformed due to a sudden gas inflow,
The variation in the resist pattern shape due to the uneven refractive index of the exposure light due to the uneven pressure can be suppressed. Note that, in this embodiment, the photomask unit 300 is
00, and is scanned, but is not limited to this. The photomask unit 300 may be scanned in a normal operation type exposure apparatus.

Embodiment 3 FIG. 5 is a cross-sectional view showing a structure of a photomask unit used in Embodiment 3 of the present invention. FIG. 5A is a cross-sectional view showing a state of the photomask unit before scanning, and FIG. FIGS. 4C and 4C are cross-sectional views each showing a state during scanning in the direction of the arrow. In FIG. 5, reference numeral 4C denotes an opening piece provided in the opening 4A. Photomask unit 40 including frame 4 having openings 4A and opening pieces 4C, photomask substrate 1, pellicle film 2, photomask pattern 3, and space 8
0 is configured.

As shown in FIGS. 5B and 5C,
In this embodiment, the opening piece 4C is on the front side in the scanning direction of the photomask unit 400, that is,
In the case where the gas flows into the space 8, the gas in the inside of the housing 5 </ b> C is closed,
To prevent large inflows into In the case where the photomask unit 400 is located on the rear side with respect to the scanning direction, that is,
When it becomes a gas outlet from the space 8, it is fully opened and the gas in the space 8 is exhausted. In order to prevent foreign matter from entering the space 8, a filter 4B for preventing foreign matter from entering the opening 4A may be provided, but the present invention is not limited to this. The other parts are the same as those in the first and second embodiments, and the description is omitted.

According to this, even when an outgas is generated from the pellicle film or the like into the space 8 during the projection exposure, the outgas is discharged and a fresh mixed gas is introduced to prevent the light transmittance from lowering. be able to. At the same time, it is possible to prevent a large amount of gas from flowing into the space 8 at one time. Therefore, it is possible to suppress a change in the shape of the resist pattern caused by the deformation of the pellicle film due to a sudden gas inflow and the uneven refractive index of the exposure light due to the uneven pressure in the space 8. Can be.

Embodiment 4 FIG. 6 is a diagram for explaining the concept of a pressure adjusting mechanism provided in opening 4A used in Embodiment 4 of the present invention. In FIG. 6, reference numeral 4D denotes a control valve as a pressure adjusting mechanism. 6 (a), 6
6B shows the same control valve 4D provided on the frame 4 of the photomask unit, and FIG. 6A shows the state of the control valve when it is located on the front side in the scanning direction of the photomask unit. FIG. 6B shows the state of the control valve when it is located on the rear side.

As shown in FIG. 6 (a), the control valve 4D
When it is on the front side with respect to the scanning direction (arrow), that is, when it is a gas inlet to the space 8, it is closed and its flow rate is controlled. Further, as shown in FIG. 6B, when the control valve 4D is located on the rear side with respect to the scanning direction (arrow), that is, when it serves as a gas outlet from the space 8, the control valve 4D is opened and there is no resistance. Drain gas. In order to prevent foreign matter from entering the space 8, a filter 4B for preventing foreign matter from entering the opening 4A may be provided, but the present invention is not limited to this. The other parts are the same as those in the first and second embodiments, and the description is omitted.

According to this, even when outgas is generated from the pellicle film or the like into the space 8 during the projection exposure, the outgas is discharged and a fresh mixed gas is introduced to prevent the light transmittance from lowering. be able to. At the same time, it is possible to prevent a large amount of gas from flowing into the space 8 at one time. Therefore, it is possible to suppress a change in the shape of the resist pattern caused by the deformation of the pellicle film due to a sudden gas inflow and the uneven refractive index of the exposure light due to the uneven pressure in the space 8. Can be.

[0075]

As described above, according to the present invention, it is possible to scan the photomask together with the support inside the housing in a non-contact state during projection exposure.
Therefore, projection exposure can be performed without being affected by outgas generated by contact of a scanning component, and projection exposure can be efficiently performed by scanning a photomask at high speed.

According to the present invention, only the photomask is scanned in the case filled with the inert gas containing the active gas. Therefore, the life of the pellicle film can be extended and the processing speed can be reduced. Projection exposure can be performed.

Further, since the inside of the photomask is also purged, even when outgas is generated from the pellicle film or the like during the projection exposure, the outgas is discharged and a fresh mixed gas is introduced to lower the light transmittance. Can be prevented.

Further, when purging the inside of the photomask, it is possible to prevent a large amount of gas from flowing at once. Therefore,
Suppress fluctuations in the shape of the resist pattern due to deformation of the pellicle film due to sudden gas inflow and uneven refractive index of exposure light due to uneven pressure in the photomask. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining the structure of a photomask storage device that stores a photomask unit used in Embodiment 1 of the present invention.

FIG. 2 is a sectional view showing the structure of the projection exposure apparatus used in the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a concept of an operation inside a housing of a scanning unit 9 for scanning the photomask storage device according to the first embodiment.

FIG. 4 is a diagram showing a structure of a photomask unit used in Embodiment 2 of the present invention.

FIG. 5 is a cross-sectional view showing a structure of a photomask unit used in Embodiment 3 of the present invention.

FIG. 6 is a diagram for explaining the concept of a pressure adjusting mechanism used in Embodiment 4 of the present invention.

FIG. 7 is a cross-sectional view illustrating a structure of a conventional photomask unit.

FIG. 8 is a perspective view showing the structure of a conventional scanning exposure apparatus. FIG.

[Explanation of symbols]

100, 300, 400 Photomask unit, 200 Photomask storage device, 1 Photomask substrate, 2 Pellicle film, 3 Photomask pattern, 4 Frame, 4A opening, 4B Filter for preventing foreign matter from entering (filter for adjusting flow rate), 4C opening Piece, 4D
Control valve, 5 housing, 5A upper plate, 5B lower plate, 5C inside, 6 support stand (adjustment means), 7A gas supply port, 7B gas recovery port, 8 space, 9 scanning means, 9A permanent magnet, 9B electromagnet, 10 interferometer, 10A reflector, 10B light source,
10C light receiver, 10D half mirror, 10E
Reference mirror, 11 masking blade, 11A aperture, 12 scan stage, 14 illumination area, 15 projection optical system, 16 table (wafer scan stage) on which substrate to be processed is mounted, 17 substrate to be processed (wafer), 18 exposure light source (F2 laser) ).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/30 518

Claims (27)

[Claims] 1. A housing including a support base for receiving and supporting a photomask opposite to the two-sided plate, wherein the two opposite-sided plates are made of a light-transmitting material; A photomask storage device, comprising: a scanning unit that scans a mask inside the housing. 2. The photomask storage device according to claim 1, wherein the housing has an opening / closing part in a part thereof so that the photomask can be exchanged. 3. The photomask storage device according to claim 1, wherein the two opposing plates are arranged at an interval of 3 cm or less. 4. The scanning unit includes:
The photomask storage device according to any one of claims 1 to 3, wherein the interior of the housing can be scanned in a non-contact state. 5. The apparatus according to claim 1, wherein the scanning unit includes a driving source capable of supplying a driving force for scanning the support table from the outside of the housing without contacting the inside of the housing. Item 5. The photomask storage device according to any one of Items 1 to 4. 6. The device according to claim 1, wherein the two opposite plates are made of calcium fluoride, barium fluoride, or fluorine-added synthetic quartz, and are coated to suppress reflection. The photomask storage device according to any one of the above. 7. The photomask storage device according to claim 1, further comprising an interferometer for detecting a position of the photomask scanned inside the housing. apparatus. 8. A frame for holding a pellicle film made of an organic material facing a surface of a photomask and extending at a predetermined interval, and sealing between the photomask and the pellicle film. A pellicle frame having an opening for flowing gas filled in a space closed by a mask, the pellicle film, and the frame. 9. The pellicle frame according to claim 8, wherein the opening is opened and closed in accordance with a scanning direction of the photomask. 10. The pellicle frame according to claim 8, wherein the opening includes a filter for adjusting a flow rate of a gas flowing through the space. 11. The pellicle frame according to claim 8, wherein the opening includes a filter for preventing foreign matter from entering the space. 12. The pellicle frame according to claim 8, wherein the opening includes a pressure adjusting mechanism for adjusting a pressure in the space. 13. The pellicle frame according to claim 12, wherein the pressure adjusting mechanism can adjust the pressure to be different depending on a scanning direction of the photomask. 14. A photomask substrate, a pellicle film opposed to a surface of the photomask substrate and stretched at a predetermined interval from the surface, a pellicle film holding the pellicle film, and the pellicle film and the photomask. A photomask unit comprising: a frame for sealing between the substrate and a substrate; wherein the pellicle frame according to claim 8 is used as the frame. 15. A projection exposure apparatus comprising: an exposure light source; and an optical system that irradiates light to be emitted from the exposure light source and transmitted through a photomask to a surface to be exposed of a substrate to be processed. A projection exposure apparatus loaded with the photomask storage device according to any one of the above. 16. The projection exposure apparatus according to claim 15, wherein the photomask unit according to claim 14 is housed in the photomask storage apparatus. 17. An exposure light source, a photomask protected by a pellicle film, and a projection optical system, wherein the light from the exposure light source irradiates a photomask pattern on the photomask to form the photomask pattern. The method of projecting and exposing the image to the surface to be exposed by the projection optical system, wherein the photomask is housed in a casing, scanned inside the casing, and projected and exposed. 18. The projection exposure method according to claim 17, wherein the photomask is scanned in a non-contact state with the inside of the housing together with a support table supporting the photomask. 19. The projection exposure method according to claim 17, wherein a driving force for scanning the support table is applied from outside the housing in a state where the driving force does not contact the inside of the housing. . 20. The photomask according to claim 17, wherein a gas in a space surrounded by the photomask, the pellicle film, and the pellicle frame is allowed to flow, and the photomask is scanned. The projection exposure method according to the above. 21. The pellicle frame according to claim 17, wherein the pellicle frame has an opening that opens in a scanning direction, and thereby scans the photomask while automatically flowing gas in the space. 20. The projection exposure method according to any one of 20. 22. The method according to claim 20, wherein when flowing the gas in the space, the photomask is scanned while adjusting the pressure in the space according to the scanning direction of the photomask. 3. The projection exposure method according to 1. 23. The projection exposure method according to claim 17, wherein the space is filled with an inert gas containing a predetermined amount of an active gas and projection exposure is performed. 24. The method according to claim 23, wherein the active gas is any one of oxygen, ozone, carbon dioxide, carbon monoxide, nitrogen oxides, oxygen sulfur, or an organic gas containing oxygen. Projection exposure method. 25. The inert gas includes nitrogen, helium,
25. The projection exposure method according to claim 23, wherein the projection exposure method is one of argon. 26. The projection exposure method according to claim 17, wherein the scanning of the photomask is performed while detecting the position of the photomask inside the housing. 27. A method for manufacturing a semiconductor device, comprising using the projection exposure method according to claim 17.