JP2007292829A - Mask for near field exposure, method for manufacturing mask for near field exposure, near field exposure device and near field exposure method using this mask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask for near field exposure that is hardly fractured upon handling for transportation, conveyance, installation or the like of the mask for near field exposure, that facilitates adhesion and peeling between a light shielding film pattern of the mask and a resist in a large area, and that results in a simple device configuration. <P>SOLUTION: The mask for near field exposure comprises a mask base 100 and a light shielding film 102 and has an aperture pattern having one or more openings 101 of a width smaller than a wavelength of exposure light in the light shielding film, wherein the mask base is made of a rubber elastic material (polydimethylsiloxane) which is transparent to exposure light. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a near-field exposure mask, a method for producing a near-field exposure mask, a near-field exposure apparatus, and a near-field exposure method using the mask, and in particular, the mask base material is composed of a rubber-like elastic material. Related technology.

As the capacity of semiconductor memories increases and the speed and integration of CPU processors increase, further miniaturization of photolithography becomes indispensable.
In general, the limit of fine processing in an optical lithography apparatus is about the wavelength of light used. For this reason, the wavelength of light used in an optical lithography apparatus has been shortened, and near-ultraviolet lasers are currently used, and fine processing of about 100 nm is possible.
Although optical lithography is progressing in this way, there are many problems that need to be solved, such as further shortening the wavelength of the laser and developing a lens in that wavelength region, in order to perform microfabrication of 100 nm or less.

On the other hand, a microfabrication apparatus using a configuration of a near-field optical microscope (hereinafter abbreviated as SNOM) has been proposed as means for enabling microfabrication of 100 nm or less by light. For example, it is an apparatus that performs local exposure exceeding the optical wavelength limit on a resist using evanescent light that oozes out from a minute aperture having a size of 100 nm or less.
However, these SNOM lithographic apparatuses have a problem that the throughput is not improved so much because they are configured to perform microfabrication with one (or several) processing probes as if they were one stroke. Was.

As a method for these, a photomask having a pattern in which the near field oozes between the light-shielding films is exposed to contact with the photoresist on the substrate, and the fine pattern on the photomask is transferred to the photoresist at once. A method has been proposed.
For example, Patent Document 1 proposes that in such near-field exposure, the thickness of the mask substrate is reduced, and the thin portion is deformed by pressure control or the like to perform adhesion peeling with the resist.
Non-Patent Document 1 proposes a method in which an elastically deformable mask using silicon having a thickness of 1 μm as a mask base material is used to be bent into a substrate by air pressure.
In Patent Document 2, it is proposed that the resist-coated substrate and the mask be secured by pressing the mask against the resist-coated substrate while the resist-coated substrate is bent and fixed to the mask side. .
Japanese Patent Laid-Open No. 2003-156834 JP 2002-367895 A Takahiko ONO and Mayaoshi EASHHI, “Subwavelength Pattern Transfer by Near-Field Photolithography” Jpn. J. et al. Appl. Phys. Vol. 37 (1998), pp. 6745-6749, Part1. NO. 12B, December 1998

By the way, in order to transfer a pattern finer than the wavelength for exposure to the resist by near-field exposure, it is necessary to make the distance between the minute opening and the resist as close as possible.
This is because the intensity distribution of the near-field light attenuates rapidly as the distance from the minute aperture increases.
Therefore, in Patent Document 1 and Non-Patent Document 1 in the above-described conventional example, a technique is employed in which the mask substrate is thinned and the thin portion is deformed by pressure control or the like to perform adhesion peeling with the resist. Yes.
However, there are slight undulations and irregularities in the resist-coated substrate. In order to perform near-field exposure on such a substrate, it is necessary to ensure that the mask adheres to waviness and irregularities in a desired region.

For example, in Patent Document 1, near-field exposure is performed by closely attaching a mask using quartz glass as a mask base material. According to this, however, quartz having rigid mechanical characteristics is required for manufacturing a semiconductor chip. It is difficult to adhere to the entire surface over a certain area, several cm square.
In Non-Patent Document 1, as described above, a method is adopted in which an elastically deformable mask using silicon having a thickness of 1 μm as a mask base material is bent by air pressure and is made to be a substrate.
However, in such a method, when the mask is quickly adhered and peeled for the purpose of improving productivity, the mask may be destroyed when pressure is applied or released due to insufficient mechanical strength.
In addition to this, when the mask substrate thickness is reduced, there arises a problem that this thin portion is broken.
As a factor of mask destruction, handling mistakes such as transportation, transportation, and setting during the mask manufacturing process can be mentioned.
In addition, during the resist exposure process, if the mask is to be peeled and peeled at a high speed, the stress may be excessively concentrated due to local deformation of the thin portion of the mask.
In order to increase the area of the mask in order to improve the throughput of near-field lithography, the above-mentioned destruction factor becomes more prominent when an attempt is made to increase the portion where the mask substrate thickness is thin.
Furthermore, since the pressure control mechanism for performing pressure control at the time of adhesion peeling, the drive mechanism for peeling in order from the substrate edge to the center of the substrate, and the like are used, the apparatus configuration becomes complicated.

In Patent Document 2, as described above, there is a method of ensuring adhesion between the resist coated substrate and the mask by pressing the mask against the resist coated substrate in a state where the resist coated substrate is bent and fixed to the mask side. It is taken.
However, in the near-field exposure, the substrate to be exposed may already be processed in the previous stage.
When such a substrate is bent, there arises a problem that a pattern already formed is disconnected, stress is concentrated in a part of the internal structure, the pattern is broken, and the pattern is not bent temporarily.
Furthermore, even if the substrate to be exposed is bent, it is difficult to bring the resist and the mask into close contact with each other over a large area if the mask base material is a hard material such as quartz.

In view of the above problems, the present invention is not easily broken during handling, transport, installation, etc. of a near-field exposure mask, and the mask light-shielding film pattern and the resist are easily peeled and peeled over a large area, and the apparatus configuration is simple. An object of the present invention is to provide a near-field exposure mask.
In addition to the above purpose, the opening pattern of the resist and the mask light-shielding film can be peeled and adhered to the resist over a large area without involving bubbles, and the throughput can be improved by exposure. The object is to provide a mask.
Furthermore, it aims at providing the manufacturing method of the near field exposure mask which has the said characteristic, a near field exposure apparatus, and the near field exposure method using this mask.

In order to solve the above problems, the present invention provides a near-field exposure mask, a near-field exposure mask manufacturing method, a near-field exposure apparatus, and a near-field exposure method using the mask, which are configured as follows. is there.
The near-field exposure mask of the present invention is a near-field exposure mask comprising an opening pattern including a mask base material and a light-shielding film, and the light-shielding film includes one or more openings having a width smaller than the wavelength of the exposure light. ,
The mask base material is formed of a rubber-like elastic body that is transparent to the exposure light.
In the near-field exposure mask of the present invention, the rubber-like elastic body is made of polydimethylsiloxane.
The near-field exposure mask of the present invention is characterized in that an intermediate layer having a Young's modulus higher than that of the mask base material of one or more layers is provided between the mask base material and the light shielding film.
Further, the near field exposure mask of the present invention, the intermediate layer, characterized in that it formed of SiO _2.
The near-field exposure mask of the present invention is characterized in that the intermediate layer is made of SiN.
The near-field exposure mask of the present invention is characterized in that the intermediate layer is made of SOG.
In the near-field exposure mask of the present invention, the mask base material and the light shielding film have a curved shape that is curved with the light shielding film side as a convex vertex.
The near-field exposure mask of the present invention is characterized in that the degree of curvature of the convex shape is 7.8 m or more as a radius of curvature.
In the near-field exposure mask of the present invention, the curved shape is formed by providing the mask base material and the light shielding film on a curved support.
In the near-field exposure mask of the present invention, the curved shape is formed by providing the light shielding film on the mask base material curved on the light shielding film side.
The near-field exposure mask of the present invention is characterized in that the curved shape is formed by providing a film having a stress for curving on the light shielding film side.
Further, the present invention is a method for producing a near-field exposure mask, the step of forming a mask base material with a rubber-like elastic body,
Forming a light shielding film;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of the exposure light on the light shielding film.
Further, the method for producing the near-field exposure mask of the present invention includes a step of forming an intermediate layer having a Young's modulus higher than that of the mask base material of one or more layers between the light shielding film and the mask base material. It is characterized by having.
Further, the present invention is a method for producing a near-field exposure mask, the step of forming a support curved in a convex shape,
Forming a mask base material with a rubber-like elastic body using the support;
Forming a light shielding film;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of the exposure light on the light shielding film.
Further, the present invention is a method for producing a near-field exposure mask, the step of forming a mask base material curved in a convex shape with a rubber-like elastic body,
Forming a light shielding film on the convex side of the mask base material formed in the convex shape;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of the exposure light on the light shielding film.
Further, the present invention is a method for producing a near-field exposure mask, the step of forming a mask base material with a rubber-like elastic body,
Forming a light shielding film;
Forming a film having a stress to bend toward the light shielding film side;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of the exposure light on the light shielding film.
Further, the near-field exposure apparatus of the present invention, a support mechanism for supporting the near-field exposure mask produced by any of the above-described near-field exposure mask or the near-field exposure mask production method,
A holding mechanism for holding a substrate exposed by the near-field exposure mask;
A drive mechanism for reducing the distance between the support mechanism and the near-field exposure mask;
It is characterized by having.
Further, the near-field exposure method of the present invention uses the near-field exposure mask described in any of the above, or a near-field exposure mask produced by the method for producing a near-field exposure mask,
After the light shielding film surface side of the near-field exposure mask and the resist surface side to be exposed are brought into contact with each other by the near-field exposure mask, exposure is performed by bringing them closer together.

According to the present invention, the handling of the near-field exposure mask is difficult to break during handling, transportation, installation, etc., and the light-shielding film pattern of the mask and the resist are easily peeled off over a large area, and the apparatus configuration is simplified.
In addition, the opening pattern of the resist and the mask light-shielding film can be adhered and peeled from the resist without entraining bubbles over a large area, thereby improving the throughput by exposure.

Next, embodiments of the present invention will be described in detail.
In the present embodiment, the mask base material of the near-field exposure mask is formed of a rubber-like elastic body.
The rubber-like elastic body here means a substance that is greatly deformed compared to glass or metal and restores its original shape when unloaded. Specifically, the Young's modulus is 1 MPa or more and 1 GPa or less.
Moreover, as a rubber-like elastic body, polydimethylsiloxane (henceforth PDMS) is mentioned, for example.
PDMS is transparent at wavelengths of 250 nm and above. Specific examples of PDMS include Sylgard 182, 184, and 186 manufactured by Dow Corning Company and marketed as Sylgard®.

By forming the mask base material with a rubber-like elastic body in this way, even when the mask is enlarged, it is possible to make it difficult to break in handling, transport, installation, etc. of the near-field exposure mask.
Further, since the opening pattern of the resist and the mask light-shielding film can be adhered and peeled from the resist at a high speed over a large area, the exposure throughput is improved.
In addition, since the mask and the resist can be adhered and peeled only by the vertical drive, the configuration of the near-field exposure apparatus becomes simple, and the apparatus cost can be reduced.
Furthermore, by making the mask have a convex structure, the opening pattern of the resist and the mask light-shielding film can be adhered to and peeled from the resist at high speed without involving bubbles, so that the exposure throughput can be improved. .

Examples to which the configuration of the present invention is applied will be described below.
[Example 1]
In Example 1, a near-field exposure mask having a mask base material made of a rubber-like elastic body will be described.
FIG. 1 shows a basic configuration of a near-field exposure mask in which the mask base material of this embodiment is made of a rubber-like elastic body.
As shown in FIG. 1, the near-field exposure mask of this embodiment is composed of a rubber-like elastic mask base material 100, a light shielding film 102, and a minute opening 101 formed in the light shielding film.
The rubber-like elastic body selected as the mask base material is transmissive to exposure light, and preferably has a Young's modulus of 1 MPa to 1 GPa, particularly preferably 1 MPa to 100 MPa.
Further, those having resistance to chemicals used in the mask manufacturing process and those having a small amount of deformation with respect to heat applied during the mask manufacturing process or near-field exposure are more preferable.

As a specific material of the rubber-like elastic body used as a mask base material, a polymer material called an elastomer is generally preferable.
The elastomer includes a crosslinked elastomer and a thermoplastic elastomer, and the crosslinked elastomer is preferable from the viewpoint of high heat resistance and a low thermal expansion coefficient.
Examples of the crosslinked elastomer include silicones such as polydimethylsiloxane (PDMS), styrenes (SBC), olefins (TPO), vinyl chlorides (TPVC), urethanes (PU), esters (TPEE), and amides. (TPAE).
In the present embodiment, an example using PDMS as a rubber-like elastic body is shown, but the present invention is not limited to these as a material for a near-field exposure mask base material, and any material satisfying the above conditions may be used. .

In the near-field exposure, the cross-sectional shape of the minute aperture 101 greatly contributes to the near-field distribution near the aperture.
For this reason, as the light shielding film 102 material, it is necessary to select a material that can easily form a minute aperture pattern as well as having a high light shielding property against exposure light.
Specifically, when i-line (wavelength: 365 nm) is used as the exposure wavelength, examples of the material having high light shielding properties include Cr, Al, AlSi, c-Si, p-Si, and a-Si. Among these, c-Si, p-Si, and a-Si are more preferable because the formation of the minute opening pattern is easy.

Next, a manufacturing method of the near-field exposure mask of this embodiment will be described with reference to FIG. First, PDMS (not shown) is applied on a smooth substrate 200 and baked (FIG. 2A).
The smooth substrate 200 is preferably a silicon substrate having at least one surface mirror-finished from the viewpoint of releasability of PDMS.
As a coating method, dipping, spin coating, spray coating, vapor deposition, or the like can be used. In the present invention, spin coating is preferred.
Baking is performed at 100 to 200 ° C. for about 10 to 60 minutes using a heating means such as a hot plate or hot air dryer.
The film thickness of PDMS is 0.1 to 1000 μm, preferably 1 to 100 μm, after curing.

Next, the PDMS film 201 serving as a mask base material is peeled from the substrate (FIG. 2B).
Here, if the PDMS film 201 alone is insufficient in handling or mounting on an apparatus, the PDMS film 201 peeled off from the smooth substrate 200 is a substrate (not shown) having a good exposure light transmission property. For example, a quartz plate.
Alternatively, the smooth substrate 200 is originally a substrate that transmits the exposure light.
Next, a light shielding film 203 is formed on the mask base material 202 thus manufactured (FIG. 2C).
For the formation of the light shielding film 203, an optimum method is selected from film formation methods such as sputtering, electron beam evaporation, resistance heating evaporation, and CVD (Chemical Vapor Deposition).
At this time, film formation conditions such as stress control, thermal expansion coefficient control, and parameter control during film formation of the light shielding film are selected so that the light shielding film does not crack due to stress or thermal contraction of the light shielding film 203.

Next, an opening pattern to be an exposure pattern is formed on the light shielding film 203. As processing methods, there are the following methods as methods for forming an opening pattern having a width smaller than the wavelength for exposure.
The light shielding film is directly processed using FIB (focused ion beam), EB (electron beam) resist is coated on the light shielding film, the EB resist is exposed with an EB drawing apparatus, developed, and etched to form the light shielding film. For example, a pattern is transferred.
As described above, a near-field exposure mask is manufactured (FIG. 2D).
By making the mask base material a rubber-like elastic body, it is possible to realize a mask that is hard to break even during handling such as transport, transport, and installation of a near-field exposure mask.
Furthermore, it is possible to realize a mask that is difficult to break even if the mask is enlarged.

Here, if necessary, an intermediate layer 204 may be formed between the light shielding film 203 and the mask base material 202 as shown in FIG.
For example, in order to further improve the accuracy in the horizontal direction in the drawing during exposure, an intermediate layer 204 that is transparent to the exposure wavelength and has a higher Young's modulus than the mask base material is formed.
Specifically, for example, by forming the SiO ₂ layer as an intermediate layer with a film thickness of 100 nm or less, the accuracy in the left-right direction can be increased.
In addition, materials such as SiN and SOG can be used as the intermediate layer.
If the adhesion between the mask base material and the light shielding film is poor, an intermediate layer may be formed for the purpose of improving the adhesion.

Next, a near-field exposure apparatus using the near-field exposure mask produced as described above and a near-field exposure method using the near-field exposure mask will be described with reference to FIG.
In FIG. 4, the near-field exposure apparatus used in this embodiment includes a mask support 300 that supports a near-field exposure mask, a substrate holder 303 that holds a substrate exposed by the near-field exposure mask, and these Is provided with a drive mechanism (not shown).
In the near-field exposure, first, a near-field exposure mask 400 composed of the mask base material 100 and the light-shielding film 102 is placed on the near-field exposure apparatus by the mask support 300.
In FIG. 4, the mask support 300 is arranged on the upper side of the figure, but the present invention is not limited to this, and it is sufficient that the near-field exposure mask 400 is fixed.
If the mask support 300 is on the optical path of the exposure light, the optical path portion increases the transmittance for the exposure light.

Next, the substrate 302 coated with the resist 301 is placed on the substrate holder 303 (FIG. 4A).
Next, the near-field exposure mask 400 and the resist 301 are aligned as necessary, and both are moved only in the vertical direction of the drawing using a driving mechanism (not shown), as shown in FIG. Adhere to.
When the substrate 302 has an uneven structure, only a part of the light shielding film 102 and the resist 301 can be in close contact as shown in FIG.
In this case, both are further pressed up and down. Even with respect to the concavo-convex shape 500 on the surface of the resist 301, only the resist 301 side of the mask base material 100 formed of a rubber-like elastic body is deformed, and can easily follow a large area (FIG. 5B). It is possible to achieve good adhesion.
Next, after the light for exposure is irradiated with the light shielding film 102 and the resist 301 in close contact with each other, the both are peeled off.
Since the mask base material 100 is formed of a rubber-like elastic body, it is possible to perform a contact and peeling operation at a higher speed as compared with a mask substrate having a small thickness. In addition, the resist 301 has excellent resistance to unevenness.
As the drive mechanism of the apparatus, only the up and down movement is required on the paper surface of FIG. It becomes simple.
A near-field exposure pattern can be formed by performing necessary processes such as baking and development on the resist-coated substrate thus exposed.

[Example 2]
Next, a description will be given of a near-field exposure mask that is gently curved so that the light shielding film side in the second embodiment of the present invention has a convex apex.
FIG. 6 shows the basic configuration of the near-field exposure mask in this embodiment.
As shown in FIG. 6, the near-field exposure mask of the present invention includes a rubber-like elastic mask base material 600, a light shielding film 602, and a minute opening 601 formed in this light shielding film.
The rubber-like elastic body selected as the mask base material is transmissive to exposure light, and preferably has a Young's modulus of 1 MPa to 1 GPa, particularly preferably 1 MPa to 100 MPa.
Further, those having resistance to chemicals used in the mask manufacturing process and those having a small amount of deformation with respect to heat applied during the mask manufacturing process or near-field exposure are more preferable.

As a specific material of the rubber-like elastic body used as a mask base material, a polymer material called an elastomer is generally preferable.
The elastomer includes a crosslinked elastomer and a thermoplastic elastomer, and the crosslinked elastomer is preferable from the viewpoint of high heat resistance and a low thermal expansion coefficient.
Examples of the crosslinked elastomer include silicones such as polydimethylsiloxane (PDMS), styrenes (SBC), olefins (TPO), vinyl chlorides (TPVC), urethanes (PU), esters (TPEE), and amides. (TPAE).
In this embodiment, an example using PDMS as a rubber-like elastic body is shown, but the present invention is not limited to these as a material for a near-field exposure mask base material, and any material satisfying the above conditions may be used. .

In the near-field exposure, the cross-sectional shape of the minute aperture 601 greatly contributes to the near-field distribution near the aperture. For this reason, as the light shielding film 602, it is necessary to select a material that can easily form a minute aperture pattern as well as having a high light shielding property against exposure light.
Specifically, when i-line (wavelength: 365 nm) is used as the exposure wavelength, examples of the material having high light shielding properties include Cr, Al, AlSi, c-Si, p-Si, and a-Si. Among these, c-Si, p-Si, and a-Si are more preferable because the formation of the minute opening pattern is easy.
These are the same as in the first embodiment.

Next, the structure and manufacturing method of the near-field exposure mask of the present invention will be described with reference to FIG. 7, FIG. 8, FIG. 9, and FIG.
First, a method for producing a near-field exposure mask for forming a mask base material and a light-shielding film on a curved support according to the first embodiment of the present embodiment will be described with reference to FIG.
First, a support body 603 having at least one curved surface is prepared (FIG. 7A). As the support 603, a material that transmits exposure light is selected.
In this embodiment, an example using quartz glass will be described, but the present invention is not limited to this.
Prepare a curved shape so that the center of the pattern formed on the light-shielding film is convex, and the height of the convex portion is about 10 μm (this means that the entire curved shape has a size of 25 mmφ). Is equivalent to about 7.81 m as the radius of curvature.
For example, a flat quartz glass plate is processed by performing a combination of semiconductor process techniques such as polishing, laser beam processing, lithography, etching, and plating. Or the type | mold which has a concave shape is produced, the support body which has a convex shape is produced by pouring a support material into it and shape | molding it.

Next, PDMS is applied as a rubber-like elastic mask base material on the support 603 and baked.
As a coating method, dipping, spin coating, spray coating, vapor deposition, or the like can be used.
Baking is performed at 100 to 200 ° C. for about 10 to 60 minutes using a heating means such as a hot plate or hot air dryer. The film thickness of PDMS is 0.1 to 1000 μm, preferably 1 to 100 μm, after curing.

A light shielding film 602 is formed on the rubber-like elastic mask base material 600 thus produced.
For the formation of the light-shielding film 602, an optimum method is selected from film formation methods such as sputtering, electron beam evaporation, resistance heating evaporation, and CVD (Chemical Vapor Deposition).
At this time, film formation conditions such as stress control, thermal expansion coefficient control, and parameter control during film formation of the light shielding film are selected so that the light shielding film is not cracked due to stress, thermal contraction, or the like of the light shielding film 602.

Next, an opening pattern serving as an exposure pattern is formed on the light shielding film 602. As a processing method, the following method is selected particularly when an opening pattern having a width smaller than the exposure wavelength is formed.
The light shielding film is directly processed using FIB (focused ion beam), EB (electron beam) resist is coated on the light shielding film, the EB resist is exposed with an EB drawing apparatus, developed, and etched to form the light shielding film. There are methods such as transferring a pattern.
As described above, a near-field exposure mask is produced (FIG. 7B).
In the above description, an example of a configuration in which one convex shape is provided for one mask has been described. However, as shown in FIG. 11, a plurality of convex shapes may be produced as necessary.
In particular, when the fine pattern and the fine pattern are far apart, the center of each pattern is designed to be the highest point of the convex shape, and by aligning the height of each other, the adhesion between the fine pattern and the resist is achieved. This time can be further shortened.

Next, a manufacturing method of a near-field exposure mask in which the light shielding film side of the mask base material according to the second embodiment of the present embodiment is curved will be described with reference to FIG.
First, a mold 703 having one side curved in a concave shape is prepared (FIG. 8A).
A concave shape having a depth of about 10 μm is manufactured (this corresponds to a radius of curvature of about 7.81 m when the entire curved shape is 25 mmφ).
It is desirable that the smoothness inside the concave shape be as good as possible. The mold material is processed by polishing, laser beam processing, lithography and a combination of semiconductor process technologies such as etching and plating.
Any mold material may be used as long as it can withstand the baking temperature for forming the mask base material and can peel the mask base material satisfactorily.

Next, a PDMS film 702 is formed using PDMS 701 as a rubber-like elastic mask base material (FIG. 8A).
In this formation, the mold 703 can be formed by spin coating, spray coating, vapor deposition, casting, or the like.
Baking is performed at 100 to 200 ° C. for about 10 to 60 minutes using a heating means such as a hot plate or hot air dryer. The film thickness of the PDMS film is 0.1 to 1000 μm, preferably 1 to 100 μm, after curing.

Next, the PDMS film 702 serving as a mask base material is peeled from the substrate (FIG. 8B).
Here, if the PDMS film 702 alone is insufficient in handling or mounting on a device, the PDMS film 702 peeled off from the mold 703 is replaced with a support substrate with good exposure light transmittance such as a quartz plate. Affixed to 603 (FIG. 8C).
A light shielding film 705 is formed on the rubber-like elastic mask base material 704 made of the PDMS film 702 thus manufactured.
For the formation of the light shielding film 705, an optimum method is selected from film formation methods such as sputtering, electron beam evaporation, resistance heating evaporation, and CVD (Chemical Vapor Deposition).
At this time, film formation conditions such as stress control, thermal expansion coefficient control, and parameter control during film formation of the light shielding film are selected so that the light shielding film does not crack due to stress, thermal contraction, or the like of the light shielding film 705.

Next, an opening pattern to be an exposure pattern is formed on the light shielding film 705 (FIG. 8D).
As a processing method, the following method is selected particularly when an opening pattern having a width smaller than the exposure wavelength is formed.
The light shielding film is directly processed using FIB (focused ion beam), EB (electron beam) resist is coated on the light shielding film, the EB resist is exposed with an EB drawing apparatus, developed, and etched to form the light shielding film. It is a method such as transferring a pattern.
In the above description, the configuration example in the case where there is one convex shape for one mask has been described, but a plurality of convex shapes may be produced as shown in FIG. 11 as necessary.
In particular, when the fine pattern and the fine pattern are far apart, the center of each pattern is designed to be the highest point of the convex shape, and by aligning the height of each other, the adhesion between the fine pattern and the resist is achieved. This time can be further shortened.

Next, a manufacturing method of a near-field exposure mask having a film for curving the mask according to the third embodiment of the present embodiment to the light shielding film side will be described with reference to FIG.
First, the support body 603 is prepared (FIG. 9A).
A convex shape is formed by forming a film 800 having stress on the support 603 (FIG. 9B).
As the film 800 having stress, for example, a SiO ₂ or SiN film is used.
Stress control is performed by selecting the film forming conditions, and a convex shape having a height of about 10 μm is formed.

Next, PDMS (not shown) is applied as a rubber-like elastic mask base material 600 and baked.
As a coating method, dipping, spin coating, spray coating, vapor deposition, or the like can be used. Baking is performed at 100 to 200 ° C. for about 10 to 60 minutes using a heating means such as a hot plate or hot air dryer.
The film thickness of the PDMS film is 0.1 to 1000 μm, preferably 1 to 100 μm, after curing.
Next, a light shielding film 602 is formed on the rubber elastic mask base material 600 thus manufactured.
For the formation of the light-shielding film 602, an optimum method is selected from film formation methods such as sputtering, electron beam evaporation, resistance heating evaporation, and CVD (Chemical Vapor Deposition).
At this time, film formation conditions such as stress control, thermal expansion coefficient control, and parameter control during film formation of the light shielding film are selected so that the light shielding film is not cracked due to stress, thermal contraction, or the like of the light shielding film 602.

Next, an opening pattern to be an exposure pattern is formed on the light shielding film 602 (FIG. 9C).
As a processing method, the following method is selected particularly when an opening pattern having a width smaller than the exposure wavelength is formed.
The light shielding film is directly processed using FIB (focused ion beam), EB (electron beam) resist is coated on the light shielding film, the EB resist is exposed with an EB drawing apparatus, developed, and etched to form the light shielding film. It is a method such as transferring a pattern.

Next, another configuration example of the near-field exposure mask having a layer for curving the mask in this embodiment to the light shielding film side will be described with reference to FIG.
These all have the support 603, but if there is no problem with only the rubber-like elastic mask base material, the support may be omitted.
In FIG. 10A, a film 801 having a stress for bending the mask to the light shielding film side is formed on the support 603 on the side opposite to the rubber-like elastic mask base material 600. Compared to FIG. 9C, since the film 801 having stress can be formed regardless of the flatness of the surface in forming the rubber-like elastic mask base material 600, the process margin when forming the film 801 having stress is increased. Spread.
The material and the formation method of the film 801 having stress are the same as those of the film 800 having stress in FIG.

In FIG. 10B, a film 801 having stress is formed between the rubber-like elastic mask base material 600 and the light shielding film 602.
In this case, the mask is bent toward the light shielding film by the film 801 having stress. Specifically, the stress of the film can be controlled by selecting conditions at the time of film formation so that a convex shape is formed on the light shielding film side.
Furthermore, when accuracy in the horizontal direction in the drawing during exposure becomes a problem, a film that is transparent to the wavelength for exposure and has a higher elastic modulus than the mask base material is formed.
Specifically, for example, by forming a SiO ₂ layer as an intermediate layer with a film thickness of 100 nm or less, it is possible to reduce variation in accuracy in the left-right direction.
If the adhesion between the mask base material and the light-shielding film is poor, a film 801 having stress may be formed for the purpose of improving the adhesion.
In FIG. 10C, the light shielding film 602 is a film 801 having a stress for bending the mask toward the light shielding film. Depending on the formation conditions of the light shielding film 602, the structure shown in FIG.
Since there is no need to separately form a film 801 having stress, the number of process steps is reduced, and the mask fabrication throughput is improved.

As described above, the mask base material is made of a rubber-like elastic material, which realizes a mask that is hard to break even during handling such as adhesion peeling to the resist during exposure and transport, transport, and installation of near-field exposure masks. it can.
Furthermore, it is possible to realize a mask that is difficult to break even if the mask is enlarged. By making the mask shape convex, it is possible to perform high-speed adhesion without entrainment of bubbles by simply moving it up and down in the vertical direction with respect to the resist surface.

Next, a near-field exposure apparatus using the near-field exposure mask produced as described above and a near-field exposure method using the near-field exposure mask will be described with reference to FIG.
As the near-field exposure apparatus, similar to the first embodiment, a support mechanism that supports a near-field exposure mask, a holding mechanism that holds a substrate exposed by the near-field exposure mask, and a drive mechanism that reduces these distances. A device having the following can be used.
First, a near-field exposure mask 900 composed of a mask base material 600 and a light shielding film 602 is installed in a near-field exposure apparatus by a mask support 300.
In FIG. 12, the mask support 300 is arranged on the upper side of the figure, but the present invention is not limited to this, and it is sufficient that the near-field exposure mask 900 is fixed.
If the mask support 300 is on the optical path of the exposure light, the optical path portion increases the transmittance for the exposure light.

Next, the substrate 302 coated with the resist 301 is placed on the substrate holder 303 (FIG. 12A).
The near-field exposure mask 900 and the resist 301 are aligned as necessary, and both are moved only in the vertical direction of the drawing using a drive mechanism (not shown).
Next, after the most convex part of the light shielding film 602 comes into contact with the resist 301, the fine opening pattern part of the light shielding film 602 is brought into close contact with the resist 301 by further moving in the vertical direction (FIG. 12B). .
Next, after the exposure light is irradiated with the light shielding film 602 and the resist 301 being in close contact with each other, peeling is performed by moving both in the vertical direction.
Since the mask base material 600 is formed of a rubber-like elastic body, it becomes a mask that is not easily broken even when the adhesion peeling operation is performed at a high speed as compared with a thin mask substrate.
Further, by making the mask shape convex toward the light shielding film side, it is possible to prevent entrainment of bubbles at the time of close contact only by vertical movement on the paper surface of FIG.
A near-field exposure pattern can be formed by performing necessary processes such as baking and development on the resist-coated substrate thus exposed.

The figure which shows the basic composition of the mask for near field exposure which comprised the mask base material in Example 1 of this invention with the rubber-like elastic body. The figure for demonstrating the preparation methods of the near-field exposure mask in Example 1 of this invention. The figure which shows the structure of the mask for near-field exposure which formed the intermediate | middle layer between the light shielding film and mask base material in Example 1 of this invention. The figure for demonstrating the near-field exposure apparatus using the mask for near-field exposure in Example 1 of this invention, and the near-field exposure method by it. The figure for demonstrating near-field exposure when the board | substrate in Example 1 of this invention has a concavo-convex structure. The figure which shows the basic composition of the mask for near field exposure which comprised the mask base material in Example 2 of this invention with the rubber-like elastic body. The figure for demonstrating the manufacturing method of the mask for near field exposure which forms a mask base material and a light shielding film on the curved support body by the 1st form in Example 2 of this invention. The figure for demonstrating the manufacturing method of the mask for near-field exposure by which the light shielding film side of the mask base material by the 2nd form in Example 2 of this invention is curving. The figure for demonstrating the manufacturing method of the mask for near field exposure which has the film | membrane for curving the mask by the 3rd form in Example 2 of this invention to the light shielding film side. The figure for demonstrating the other structural example of the mask for near field exposure which has the layer for curving the mask in Example 2 of this invention to the light shielding film side. The figure for demonstrating the structural example which produced several convex shape with respect to one mask in Example 2 of this invention. The figure for demonstrating the near field exposure apparatus using the mask for near field exposure in Example 2 of this invention, and the near field exposure method by it.

Explanation of symbols

100: Rubber-like elastic mask base material 101: Micro opening 102: Light shielding film 200: Smooth substrate 201: PDMS film 202: Mask base material 203: Light shielding film 204: Intermediate layer 300: Mask support 301: Resist 302: Substrate 303: Substrate holder 400: Near-field exposure mask 500: Uneven structure 600: Rubber elastic mask base material 601: Micro opening 602: Light shielding film 603: Support 701: PDMS film 702: PDMS film 703: Mold 704: Rubber-like elastic mask base material 705: light shielding film 800: stressed film 900: near-field exposure mask

Claims (18)

In a near-field exposure mask comprising a mask base material and a light shielding film, and having an opening pattern including one or more openings having a width smaller than the wavelength of exposure light in the light shielding film,
The near-field exposure mask, wherein the mask base material is made of a rubber-like elastic body that is transparent to the exposure light.   The near-field exposure mask according to claim 1, wherein the rubber-like elastic body is made of polydimethylsiloxane.   3. The near-field exposure according to claim 1, further comprising an intermediate layer having a Young's modulus higher than that of the mask base material of one or more layers between the mask base material and the light shielding film. mask. The near-field exposure mask according to claim 3, wherein the intermediate layer is made of SiO ₂ .   The near-field exposure mask according to claim 3, wherein the intermediate layer is made of SiN.   The near-field exposure mask according to claim 3, wherein the intermediate layer is made of SOG.   The near-field exposure according to claim 1, wherein the mask base material and the light shielding film have a curved shape that is curved with the light shielding film side as a convex vertex. Mask.   The near-field exposure mask according to claim 7, wherein the degree of curvature of the convex shape is 7.8 m or more as a radius of curvature.   9. The near-field exposure mask according to claim 7, wherein the curved shape is formed by providing the mask base material and the light shielding film on a curved support.   9. The near-field exposure mask according to claim 7, wherein the curved shape is formed by providing the light shielding film on the mask base material curved on the light shielding film side.   9. The near-field exposure mask according to claim 7, wherein the curved shape is formed by providing a film having a stress to bend toward the light shielding film side. A method for producing a near-field exposure mask according to claim 1 or 2,
Forming a mask base material with a rubber-like elastic body;
Forming a light shielding film;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of exposure light in the light-shielding film;
A method for producing a near-field exposure mask, comprising:   13. The near-field exposure method according to claim 12, further comprising a step of forming an intermediate layer having a Young's modulus higher than that of one or more layers of the mask base material between the light shielding film and the mask base material. A method for manufacturing a mask. A method for producing a near-field exposure mask according to claim 7 or 8,
Forming a support curved in a convex shape;
Forming a mask base material with a rubber-like elastic body using the support;
Forming a light shielding film;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of exposure light in the light-shielding film;
A method for producing a near-field exposure mask, comprising: A method for producing a near-field exposure mask according to claim 7 or 8,
Forming a mask base material curved into a convex shape with a rubber-like elastic body;
Forming a light shielding film on the convex side of the mask base material formed in the convex shape;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of exposure light in the light-shielding film;
A method for producing a near-field exposure mask, comprising: A method for producing a near-field exposure mask according to claim 7 or 8,
Forming a mask base material with a rubber-like elastic body;
Forming a light shielding film;
Forming a film having a stress to bend toward the light shielding film side;
Forming an opening pattern including at least one opening having a width smaller than the wavelength of exposure light in the light-shielding film;
A method for producing a near-field exposure mask, comprising: A support for supporting the near-field exposure mask produced by the method for producing a near-field exposure mask according to any one of claims 1 to 11 or the near-field exposure mask according to any one of claims 12 to 16. Mechanism,
A holding mechanism for holding a substrate exposed by the near-field exposure mask;
A drive mechanism for reducing the distance between the support mechanism and the near-field exposure mask;
A near-field exposure apparatus comprising: Using the near-field exposure mask according to any one of claims 1 to 11 or the near-field exposure mask produced by the method for producing a near-field exposure mask according to any one of claims 12 to 16,
A near-field exposure method comprising: exposing a light-shielding film side of the near-field exposure mask and a resist surface side to be exposed by the near-field exposure mask, and then performing exposure by bringing them closer together.

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