JP7019472B2 - Method for manufacturing carbon nanotube free-standing film and method for manufacturing pellicle - Google Patents

Description

The present invention relates to an exposure original plate or reticle (hereinafter, collectively referred to as "exposure original plate") used when manufacturing a semiconductor device or the like by lithography technology, and a dustproof cover for an exposure original plate to prevent dust from adhering to the exposure original plate or reticle. Regarding pellicle etc. In particular, the present invention relates to a method for producing a carbon nanotube self-supporting film used as a pellicle film, which is an ultrathin film for extreme ultraviolet light (EUV) lithography, and a method for producing a pellicle.

In the manufacturing process of semiconductor devices such as large-scale integrated circuits (LSIs) and superLSIs and liquid crystal display plates, patterning is performed by irradiating a photosensitive layer or the like with light via a mask (exposed original plate, also referred to as a reticle). At that time, if foreign matter adheres to the mask, the light is absorbed by the foreign matter, or the light is reflected by the foreign matter surface and bent. As a result, there arises a problem that the formed pattern is deformed or the edges are rough, and the dimensions, quality, appearance, etc. after patterning are impaired. In order to solve such a problem, a method is adopted in which a pellicle provided with a pellicle film that transmits light is attached to the surface of the mask to suppress the adhesion of foreign matter.

The wavelength of light used for lithography is becoming shorter, and EUV light is being studied as a next-generation lithography technology. EUV light refers to light having a wavelength in the soft X-ray region or vacuum ultraviolet region, and specifically refers to light rays having a wavelength of about 13.5 nm ± 0.3 nm.

EUV light is easily absorbed by all substances. When the pellicle film absorbs EUV light, it not only causes exposure failure, but also may damage the pellicle film due to heat generated by the energy of EUV light. Therefore, it is considered that the conventional pellicle film for ArF light, for example, is not suitable for EUV light.

The pellicle film for EUV pellicle is usually manufactured by laminating silicon nitride (SiN) or the like on a silicon wafer substrate. On the other hand, the development of a pellicle using a carbon nanotube film as a material having high transparency to EUV light and high resistance to EUV is underway. Patent Document 1 and Patent Document 2 disclose EUV pellicle using a carbon nanotube film.

International Publication No. 2014/142125 International Publication No. 2018/008594

However, when a carbon nanotube film is used as a pellicle film, it is difficult to stably produce a self-supporting film (meaning a film that can continue to exist as a film without having a support member on any surface).

In view of such problems, one embodiment of the present invention aims to stably produce a self-supporting film for carbon nanotubes. Another embodiment of the present invention aims to stably produce a pellicle using a carbon nanotube self-supporting membrane.

According to one embodiment of the present invention, the carbon nanotube film is formed on the first surface of the substrate having the first surface and the second surface on the opposite side of the first surface, and the carbon nanotube film and the first frame-shaped member are formed. Provided is a method for manufacturing a carbon nanotube self-standing film, which is connected, the substrate is dry-etched from the first surface side, and the carbon nanotube film is separated from the substrate.

In the method for producing a self-supporting film for carbon nanotubes, dry etching may be performed using an etching gas having an etching rate of the substrate in the range of 0.01 μm / min or more and 10 μm / min or less.

In the method for producing a self-supporting carbon nanotube film, the substrate may have a sacrificial layer on the first surface side, the carbon nanotube film may be formed on the sacrificial layer, and the sacrificial layer may be removed by dry etching.

In the method for producing a self-supporting film for carbon nanotubes, the sacrificial layer may contain at least one of polycrystalline silicon, amorphous silicon, silicon oxide, and aluminum.

In the method for producing a self-supporting film for carbon nanotubes, at least one of XeF ₂ gas and HF gas may be used for dry etching.

In the method for producing a self-supporting carbon nanotube film, the thickness of the carbon nanotube film may be 10 nm or more and 200 nm or less.

In the method for manufacturing a self-standing carbon nanotube film, when the carbon nanotube film is separated, a second frame-shaped member smaller than the first frame-shaped member is connected to the carbon nanotube film, and the second frame-shaped member is separated from the substrate. You may move it.

In the method for producing a self-supporting carbon nanotube film, the carbon nanotube film and the second frame-shaped member may be connected via a van der Waals force.

In the method for producing a self-supporting carbon nanotube film, static electricity may be applied to the second frame-shaped member before connecting the carbon nanotube film and the second frame-shaped member.

In the method for manufacturing the carbon nanotube self-standing film, the charged member may be brought close to the second frame-shaped member before the carbon nanotube film and the second frame-shaped member are connected to each other.

In the method for producing a self-standing film of carbon nanotubes, the volume resistivity of the charged member may be 10 ¹⁴ Ω · cm or more.

In the method for producing a self-standing film of carbon nanotubes, the second frame-shaped member and the carbon nanotube film may be adhered to each other by using an adhesive.

According to one embodiment of the present invention, there is provided a method for manufacturing a pellicle in which the carbon nanotube self-standing film is used as a pellicle film and the pellicle film and a third frame-shaped member smaller than the second frame-shaped member are connected to each other. To.

According to one embodiment of the present invention, an exposed original plate including the original plate and the pellicle mounted on the surface having the pattern of the original plate is used, and the light emitted from the light source is transmitted through the pellicle film. Provided is a method for manufacturing a semiconductor device, which irradiates an original plate, reflects it on the original plate, transmits the light reflected by the original plate to the sensitive substrate through a pellicle film, and irradiates the sensitive substrate in a pattern.

In the method for manufacturing a semiconductor device, the light may be EUV light.

By using one embodiment of the present invention, a self-supporting film for carbon nanotubes can be stably produced. Further, by using another embodiment of the present invention, a pellicle can be stably produced by using the carbon nanotube self-standing film.

It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional drawing which shows the manufacturing method of the pellicle which concerns on one Embodiment of this invention. It is a top view and sectional drawing which shows the manufacturing method of the pellicle which concerns on one Embodiment of this invention. It is the top view and sectional drawing of the pellicle which concerns on one Embodiment of this invention. It is a schematic diagram of the exposure apparatus which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention. It is a top view and sectional view which shows the manufacturing method of the carbon nanotube self-standing film which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in many different embodiments and is not construed as being limited to the description of the embodiments exemplified below. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

As used herein, when a member or region is "above (or below)" another member or region, it is directly above (or directly below) the other member or region, unless otherwise specified. ), As well as above (or below) the other member or region, i.e., with another component in between above (or below) the other member or region. Including cases.

As used herein, EUV light refers to light having a wavelength of 5 nm or more and 30 nm or less. The wavelength of EUV light is preferably 5 nm or more and 14 nm or less, and specifically, EUV light refers to light of about 13.5 nm ± 0.3 nm.

In the present specification, trimming is to cut a substrate or a substrate and a pellicle film formed on the substrate according to a desired pellicle shape. Since most of the pellicle shapes are rectangular, this specification shows an example of cutting into a rectangular shape as a specific example of trimming.

<First Embodiment>
(1-1. Method for manufacturing self-supporting film of carbon nanotube)
A method for producing a carbon nanotube free-standing film used for a pellicle for EUV photolithography will be described with reference to FIGS. 1 to 8.

(1-1-1. Formation of carbon nanotube film)
First, as shown in FIG. 1, the carbon nanotube film 120 is formed on the first surface 110-1 side of the substrate 110 having the first surface 110-1 and the second surface 110-2.

An inorganic material is used for the substrate 110. For example, silicon (Si) is used for the substrate 110. The substrate 110 is not limited to silicon (Si), and may be a semiconductor material such as germanium (Ge), silicon germanium (SiGe), silicon carbide (SiC), gallium arsenide (GaAs), or a quartz glass substrate (oxidation). Silicon (SiO ₂ )), soda glass substrate, borosilicate glass substrate, glass substrate such as sapphire substrate, silicon nitride (SiN), aluminum nitride (AlN) substrate, zirconia (ZrO ₂ ) substrate, aluminum oxide (Al ₂ O ₃ ) ) And so on. Further, in order to reduce the thermal strain with the carbon nanotube film 120, the substrate 110 preferably contains at least one of silicon, sapphire, and silicon carbide having a linear thermal expansion rate close to that of the pellicle film. Further, the silicon (Si) may be any of polycrystalline silicon, microcrystalline silicon, and amorphous silicon, but polycrystalline silicon is preferable from the viewpoint of etching efficiency. The shape of the substrate 110 may be circular or rectangular. The thickness of the substrate 110 is not particularly limited, but is preferably 100 μm or more and 1000 μm or less, and preferably 200 μm or more and 500 μm or less from the viewpoint of handling.

The carbon nanotubes (may be carbon nanotube bulk structures) used in the present embodiment are used for chemical vapor deposition by a CVD (Chemical Vapor Deposition) method in which a metal catalyst is present in the reaction system and an oxidizing agent is added to the reaction atmosphere. It is preferable to use one formed on the substrate. As the CVD method, for example, a plasma CVD method is used, but a low voltage CVD method or a thermal CVD method may be used. At this time, water vapor is used as the oxidizing agent. The concentration of water vapor may be 10 ppm or more and 10000 ppm or less, and water vapor may be added in a temperature environment of 600 ° C. or more and 1000 ° C. or less. Further, carbon nanotubes may be synthesized by arranging or patterning a metal catalyst on a base material for chemical vapor deposition. Further, the obtained carbon nanotubes may be single-walled or multi-walled, or may be carbon nanotubes that are erected in a direction perpendicular to the surface of the base material for chemical vapor deposition. For details, it can be manufactured with reference to, for example, International Publication No. 2006/011655. Examples of commercially available products of such carbon nanotubes include carbon nanotubes manufactured by the Super Growth method sold by Zeon Corporation.

Further, as the carbon nanotube (which may be a carbon nanotube bulk structure) used in this embodiment, one manufactured by an improved direct injection pyrolytic synthesis method (hereinafter referred to as an e-DIPS method) is used. Is preferable. The direct injection pyrolytic synthesis method (hereinafter referred to as the DIPS method) is a hydrocarbon-based solution containing a catalyst (or catalyst precursor) and a reaction accelerator atomized by spraying and heated at a high temperature. This is a gas phase flow method in which a single-layer carbon nanotube is synthesized in a flowing gas phase by introducing it into a furnace. The e-DIPS method, which is an improvement of this DIPS method, focuses on the particle formation process in which the ferrocene used in the catalyst has different particle sizes on the upstream and downstream sides of the reaction reactor, and has used only an organic solvent as a carbon source. Unlike the DIPS method, it is a method in which the growth point of the single-walled carbon nanotube is controlled by mixing a second carbon source which is relatively easily decomposed in the carrier gas, that is, which is likely to be a carbon source. For details, see Saito et al. , J. Nanosci. Nanotechnol. , 8 (2008) 6153-6157. Examples of commercially available products of such carbon nanotubes include the trade name “MEIJO eDIPS” manufactured by Meijo Nanocarbon Co., Ltd.

The carbon nanotubes (or carbon nanotube bulk structures) obtained by the CVD method, the e-DIPS method, or the like are used in a state of being dispersed in a solvent. A carbon nanotube film 120 is formed on the substrate 110 by applying a liquid (dispersion liquid) in which carbon nanotubes (or carbon nanotube bulk structures) are dispersed on the substrate 110 and evaporating and removing the solvent. In the case of the present embodiment, by removing the solvent used in the dispersion liquid, a film in which the carbon nanotubes are substantially parallel to the first surface 110-1 of the substrate 110 can be obtained (that is, the first surface 110- It can be said that there are few carbon nanotubes erected in the direction perpendicular to 1.). The above coating method is not particularly limited, and for example, spin coating, dip coating, bar coating, spray coating, electrospray coating and the like may be used. The metal catalyst used to form the carbon nanotubes may cause a decrease in EUV permeability, but when the carbon nanotubes are peeled off from the chemical vapor deposition substrate, most of the metal catalyst is contained in the carbon nanotubes. There is no effect because there is no such thing.

The thickness of the carbon nanotube film 120 obtained by the above method is 10 nm or more and 200 nm or less, preferably 10 nm or more and 100 nm or less, more preferably 10 nm or more and 70 nm or less, still more preferably 10 nm or more and 50 nm or less, and most preferably 10 nm or more and 45 nm or less. Is desirable.

Further, the diameter of the carbon nanotubes contained in the carbon nanotube film 120 described above is 0.8 nm or more and 6 nm or less, the length of the carbon nanotubes is 10 μm or more and 10 cm or less, and the carbon content in the carbon nanotubes is 98% by mass. It is desirable that the above is the case.

(1-1-2. Connection with frame-shaped member)
Next, as shown in FIG. 2, the carbon nanotube film 120 and the frame-shaped member 130 (also referred to as the first frame-shaped member) are connected. A material different from that of the substrate 110 is used for the frame-shaped member 130. For example, stainless steel is used for the frame-shaped member 130. The frame-shaped member 130 is not limited to stainless steel, but is limited to brass, aluminum, aluminum alloys (5000 series, 6000 series, 7000 series, etc.), metal materials such as copper, and organic resins such as fluororesin, acrylic resin, and epoxy resin. Materials, ceramic materials such as boron nitride, silicon nitride, aluminum oxide and graphite may be used. Further, the frame-shaped member 130 has a frame shape when viewed from above. At this time, as shown in FIG. 3A, the frame-shaped member 130 may be, for example, a rectangle, a polygon, or an annular shape.

Further, when connecting the carbon nanotube film 120 and the frame-shaped member 130, the adhesive 128 may be used. The adhesive 128 may be in the form of a film or may be cured and used in a liquid form. For the adhesive 128, for example, an organic resin material such as an acrylic resin, an epoxy resin, a silicone resin, or a polyimide resin is used.

(1-1-3. Etching of substrate)
Next, as shown in FIG. 3, the substrate 110 is etched by a dry etching method from the first surface 110-1 side on which the carbon nanotube film 120 is provided.

Here, the etching of the substrate 110 by the dry etching method will be described. The carbon nanotube film 120 provided on the substrate 110 is connected so that the carbon nanotubes form an in-plane network, and has a large number of voids. Since the voids are sufficiently larger than the reaction gas used in the dry etching method, the reaction gas can permeate through the carbon nanotube film and cause the substrate to react with the reaction gas. Therefore, by using the dry etching method, only the substrate 110 can be etched without etching the carbon nanotube film 120. Further, at this time, the portion 110A of the substrate 110 that overlaps with the frame-shaped member 130 remains without being completely removed because the frame-shaped member 130 serves as a mask. As a result, the carbon nanotube film 120 is supported by the portion 110A of the substrate 110, and the central portion of the substrate 110 and the central portion of the carbon nanotube film 120 are maintained in a separated state without recontacting. When the substrate 110 is etched by the dry etching method, the etching method may be isotropic dry etching or anisotropic dry etching. Isotropic dry etching is preferable from the viewpoint of preventing etching defects due to foreign matter and the like and separating the carbon nanotube film from the substrate 110 more stably. The width of the frame-shaped member 130 is preferably 0.1 mm or more and 50 mm or less from the viewpoint of preventing recontact between the carbon nanotube film 120 and the substrate 110 while leaving the overlapping portion 110A and from the viewpoint of handleability of the frame-shaped member 130. .. Further, from the viewpoint of the strength and handleability of the frame-shaped member 130, the width of the frame-shaped member 130 is preferably 1 mm or more and 50 mm or less.

The dry etching method is preferably a dry etching method that does not use plasma from the viewpoint of reducing damage to carbon nanotubes. Further, as the gas 137 used in the dry etching method, a gas capable of etching the substrate 110 is used. At this time, it is desirable that the etching rate of the substrate 110 is high in order to reduce damage to the carbon nanotubes. For example, it is desirable to use an etching gas having an etching rate of the substrate 110 in the range of 0.01 μm / min or more and 10 μm / min or less. The damage to the carbon nanotubes referred to here includes cutting and alteration of the carbon nanotubes themselves by the etching gas. When the etching time of the substrate 110 becomes long and the etching gas reacts with carbon, the carbon-carbon bond may be broken, the length of the carbon nanotube may be shortened, or holes may be formed in the carbon nanotube film 120. If the length of the carbon nanotubes is shortened, the strength of the carbon nanotube film 120 may not be maintained, or the crystallinity of the carbon nanotubes may be lowered. Alternatively, if the carbon nanotube film 120 has holes, the pellicle film may not have dustproof properties. Therefore, damage to the carbon nanotubes can be reduced by etching the substrate 110 at the above-mentioned etching rate. Specifically, the etching time of the substrate 110 is preferably 1 hour or less, preferably 30 minutes or less, and more preferably 20 minutes or less.

Specific examples of the etching gas are not particularly limited as long as the substrate 110 can be etched, but for example, F ₂ , CF ₄ , C ₄ F ₈ , CHF ₃ , XeF ₆ , XeF ₂ , SF ₆ , O ₂ , O ₃ , H ₂ O, H ₂ O ₂ , N ₂ O, NO, NO ₂ , HNO ₃ , Cl ₂ , HCl, HF, I ₂ , HI, Br ₂ , HBr, NOCl, PCl ₃ , PCl ₅ , PF ₃ , NF ₃ or These combinations can be exemplified.

When a silicon substrate is etched by a dry etching method as the substrate 110, specifically, a gas such as XeF ₂ , SF ₆ , CF ₄ or C ₄ F ₈ is used. Of these, XeF ₂ has a high etching rate of the silicon substrate, and the etching time of the substrate 110 can be shortened. Therefore, it is desirable because the damage to the carbon nanotube film 120 can be reduced.

Alternatively, when a quartz glass substrate containing silicon oxide (SiO ₂ ) is used as the substrate 110, gases such as hydrogen fluoride (HF), SF ₆ , CHF ₃ or C ₄ F ₈ and hydrogen (H ₂ ) are used. .. Of these, HF gas has a high etching rate of the glass substrate, and the etching time of the substrate 110 can be shortened. Therefore, it is desirable because the damage to the carbon nanotube film 120 can be reduced.

(1-1-4. Separation of carbon nanotube film)
Next, as shown in FIG. 4, the frame-shaped member 140 (also referred to as a second frame-shaped member) is superimposed on the carbon nanotube film 120. At this time, it is preferable that the frame-shaped member 140 is sandwiched between the working devices 150. The same material as the frame-shaped member 130 can be used for the frame-shaped member 140. The frame-shaped member 140 has an outer shape smaller than that of the frame-shaped member 130 in top view.

Next, as shown in FIG. 5, the charging member 160 is arranged on the working apparatus 150. The material of the charging member 160 is not particularly limited, but a material that is easily charged is used. Specifically, a material having a volume resistivity of 10 ¹⁴ Ω · cm or more is used for the charging member 160, and more specifically, an insulating material such as fluororesin, acrylic resin, or polycarbonate is used. These insulating materials are charged by contact electrification, peeling electrification, etc., and have a charge amount of several kV or more. By bringing the charging member 160 close to the frame-shaped member 140, electrostatic induction occurs, and static electricity can be applied to the frame-shaped member 140. If the workpiece 150 is sufficiently charged, the charging member 160 can be omitted. Further, the charging member 160 may be installed on the working apparatus 150 in advance before the frame-shaped member 140 is superimposed on the carbon nanotube film 120.

Next, as shown in FIG. 6, the workpiece 150 is moved toward the carbon nanotube film 120, and the frame-shaped member 140 is brought closer to the carbon nanotube film 120. At this time, the frame-shaped member 140 and the carbon nanotube film 120 are connected via static electricity. At the interface between the frame-shaped member 140 and the carbon nanotube film 120, the frame-shaped member 140 and the carbon nanotube film 120 are bonded to each other via a van der Waals force generated by an electric charge bias. The charging member 160 may be installed on the working apparatus 150 after the frame-shaped member 140 is brought close to the carbon nanotube film 120.

In addition to the charging member 160, another member may be used to increase the charging amount. Specifically, a device that generates static electricity, such as an ionizer, may be used.

Next, as shown in FIG. 7, the frame-shaped member 140 is moved together with the working device 150 in a direction away from the first surface 110-1 of the substrate 110. At this time, a part of the carbon nanotube film 120 is separated from the substrate 110, and a self-supporting film of carbon nanotubes (carbon nanotube self-supporting film 125) is manufactured. The outer portion of the frame-shaped member 140 of the manufactured carbon nanotube self-standing film 125 may be appropriately removed by trimming.

(1-2. Manufacturing method of pellicle)
Next, a method for producing a pellicle will be described with reference to FIGS. 8 and 9.

First, as shown in FIG. 8, the frame-shaped member 190 (also referred to as the third frame-shaped member) and the carbon nanotube self-standing film 125 are superimposed. The frame-shaped member 190 is smaller than the frame-shaped member 140 in top view. The frame-shaped member 190 is used as a pellicle frame 195. Therefore, a known pellicle frame can be used for the frame-shaped member 190. The material of the frame-shaped member 190 is not particularly limited, but aluminum or an aluminum alloy (5000 series, 6000 series, 7000 series, etc.), stainless steel, titanium, silicon, or the like is preferable from the viewpoint of achieving both lightness and strength. The surface of the frame-shaped member 190 may be provided with a material having resistance to EUV. Specific examples thereof include materials containing one or more elements selected from Mo, Ru, and B. Further, at this time, alcohol such as isopropyl alcohol or water may be attached to the portion 190A of the frame-shaped member 190 that comes into contact with the carbon nanotube self-standing film 125. Further, the portion 190A may be provided with an adhesive 185. The material of the adhesive 185 is not particularly limited, but is preferably an organic resin material such as an acrylic resin, an epoxy resin, a silicone resin, or a polyimide resin, and more preferably an organic resin material having resistance to EUV light. preferable.

Next, the carbon nanotube self-supporting film 125 and the frame-shaped member 190 are connected using an adhesive 185. Next, as shown in FIG. 9, a part of the carbon nanotube self-standing film 125 is separated from the frame-shaped member 140. As a result, the pellicle 200 is manufactured as shown in FIG. The carbon nanotube free-standing film 125 is used as the pellicle film 180. Since the height of the manufactured EUV pellicle is limited, the total height of 10 h including the pellicle film 180 and the pellicle frame 195 is preferably 3.0 mm or less, more preferably 2.5 mm or less. It is preferable to be.

After that, other treatments such as trimming the carbon nanotube self-supporting film 125 and coating with the adhesive 185 may be performed.

(1-3. Use of pellicle)
The pellicle of the present embodiment can be attached to the original plate and used as an exposure original plate. Further, the pellicle of the present embodiment is not only a protective member for suppressing foreign matter from adhering to the original plate in the EUV exposure apparatus, but also a protection for protecting the original plate during storage of the original plate and transportation of the original plate. It may be used as a member. For example, if the pellicle is attached to the original plate (exposure original plate), it can be stored as it is after being removed from the EUV exposure apparatus. Methods for attaching the pellicle to the original plate include a method of attaching with an adhesive, an electrostatic adsorption method, a method of mechanically fixing the pellicle, and the like.

Here, as the original plate, an original plate including a support substrate, a reflective layer laminated on the support substrate, and an absorber layer formed on the reflective layer may be used. When the absorber layer partially absorbs EUV light, a desired image is formed on the sensitive substrate (for example, a semiconductor substrate with a photoresist film). The reflective layer can be a multilayer film of molybdenum (Mo) and silicon (Si). The absorber layer can be a material having high absorbency such as EUV light such as chromium (Cr) and tantalum nitride.

(1-4. Exposure device)
The exposure apparatus using the exposure original plate including the pellicle manufactured in the present embodiment will be described below. FIG. 11 is a schematic cross-sectional view of the EUV exposure apparatus 280, which is an example of the exposure apparatus of the present embodiment. As shown in FIG. 11, the EUV exposure apparatus 280 includes a light source 282 that emits EUV light, an exposure original plate 281 and an illumination optical system 283 that guides EUV light emitted from the light source 282 to the exposure original plate 281. ..

In the EUV exposure apparatus 280, the EUV light emitted from the light source 282 is collected by the illumination optical system 283, the illuminance is made uniform, and the exposure original plate 281 is irradiated. The EUV light applied to the exposed original plate 281 is reflected in a pattern by the original plate 284.

The exposure original plate 281 is an example of the exposure original plate of the present embodiment. That is, the pellicle 200, which is an example of the pellicle of the present embodiment including the pellicle film 180 and the pellicle frame 195, and the original plate 284 are provided. The exposure original plate 281 is arranged so that the EUV light emitted from the light source 282 passes through the pellicle film 180 and irradiates the original plate 284.

The illumination optical system 283 includes a plurality of multilayer mirrors 289 for adjusting the optical path of EUV light, an optical coupler, and the like.

As the light source 282 and the illumination optical system 283, known light sources and illumination optical systems can be used.

In the EUV exposure apparatus 280, filter windows 285 and 286 are installed between the light source 282 and the illumination optical system 283, and between the illumination optical system 283 and the original plate 284, respectively. The filter windows 285 and 286 are capable of capturing scattered particles (debris). Further, the EUV exposure apparatus 280 includes a projection optical system 288 that guides the EUV light reflected by the original plate 284 to the sensitive substrate 287. In the EUV exposure apparatus 280, the EUV light reflected by the original plate 284 and transmitted through the pellicle film 180 is guided onto the sensitive substrate 287 through the projection optical system 288, and the sensitive substrate 287 is exposed in a pattern. The exposure by EUV is performed under reduced pressure conditions. The projection optical system 288 includes a plurality of multilayer mirrors 290, 291 and the like. As the filter window 285, the filter window 286, and the projection optical system 288, known projection optical systems can be used.

The sensitive substrate 287 is a substrate or the like on which a resist is coated on a semiconductor wafer, and the resist is cured in a pattern by EUV light reflected by the original plate 284. By developing this resist and etching the semiconductor wafer, a desired pattern is formed on the semiconductor wafer.

Based on the above, in the exposure apparatus 280, the exposure original plate including the original plate and the pellicle manufactured in the present embodiment mounted on the surface having the pattern of the original plate is used, and the light emitted from the light source is used as the pellicle film. The sensitive substrate can be exposed in a pattern by transmitting the light to the original plate, reflecting the light on the original plate, and transmitting the light reflected by the original plate to the sensitive substrate through the pellicle film. A semiconductor device is manufactured by appropriately combining this process, an etching process, and the like.

By using the above method, in addition to being able to form a finely divided pattern (for example, a line width of 32 nm or less) by EUV light or the like, even when EUV light is used, which tends to cause a problem of poor resolution due to foreign matter. Pattern exposure with reduced resolution defects due to foreign matter can be performed.

<Second Embodiment>
In this embodiment, a method for producing a self-supporting carbon nanotube film different from that of the first embodiment will be described. The description thereof will be referred to for the same materials and methods as in the first embodiment.

In this embodiment, as shown in FIG. 12, the substrate 110 has a sacrificial layer 115 on the first surface 110-1 side. The carbon nanotube film 120 is formed on the sacrificial layer 115. The sacrificial layer 115 is a layer removed by a dry etching method. The material of the sacrificial layer 115 is not particularly limited, but it is desirable that the material has a high etching selectivity with the substrate 110. The sacrificial layer 115 may be a semiconductor material such as polycrystalline silicon, microcrystalline silicon, or amorphous silicon, an inorganic insulating material such as silicon oxide or silicon nitride, or a metal material such as aluminum, tungsten, or titanium. An organic insulating material such as parylene may be used. The sacrificial layer 115 is formed by a physical vapor deposition method, a coating method, a plasma CVD method, a printing method, or the like. For example, when a silicon substrate is used for the substrate 110, a silicon oxide film formed by a plasma CVD method may be used for the sacrificial layer 115. The film thickness of the sacrificial layer 115 is preferably 0.01 μm or more and 100 μm or less, preferably 1 μm or more and 50 μm or less.

Next, as shown in FIG. 13, the sacrificial layer 115 is etched by a dry etching method. The gas 137 used for etching the sacrificial layer 115 is not particularly limited, and may be appropriately changed according to the material of the sacrificial layer 115. For example, when a silicon oxide (SiO ₂ ) film is used for the sacrificial layer 115, it is desirable to dry etch using HF gas. The etching rate of the silicon oxide film when HF gas is used is 0.01 μm / min or more and 10 μm / min or less, and the etching selectivity with the silicon substrate can be increased. Similarly, when polycrystalline silicon is used for the sacrificial layer 115, it is desirable to perform dry etching using xenon fluoride (XeF ₂ ) gas. The etch rate of the polycrystalline silicon film when XeF ₂ gas is used is 0.01 μm / min or more and 10 μm / min or less.

Alternatively, when the aluminum (Al) film is etched by the dry etching method as the sacrificial layer 115, one of chlorine (Cl ₂ ), boron trichloride (BCl ₃ ), or carbon tetrachloride (CCl ₄ ) is used. May be.

(Modification 1)
In the first embodiment of the present invention, an example in which the frame-shaped member 140 and the carbon nanotube film 120 are connected and then separated is shown, but the present invention is not limited thereto. For example, when the frame-shaped member 140 is brought close to the frame-shaped member 140, the carbon nanotube film 120 may be attracted by electrostatic attraction to separate a part thereof, and the carbon nanotube self-standing film 125 may be connected to the frame-shaped member 140.

(Modification 2)
In the first embodiment of the present invention, an example is shown in which static electricity is applied to the frame-shaped member 140 to connect the carbon nanotube film 120 to the carbon nanotube film 120 by a van der Waals force, but the present invention is not limited thereto. For example, as shown in FIG. 14, the frame-shaped member 140 and the carbon nanotube film 120 may be connected by an adhesive 145. The adhesive 145 may be in the form of a film or may be cured and used in a liquid form. For the adhesive 145, for example, an organic resin material such as an acrylic resin, an epoxy resin, a silicone resin, or a polyimide resin is used.

(Modification 3)
In the first embodiment of the present invention, a method for manufacturing a carbon nanotube self-standing film and a pellicle using a frame-shaped member 130, a frame-shaped member 140, and a frame-shaped member 190 has been described, but the present invention is not limited thereto. For example, the frame-shaped member 190, which is the pellicle frame 195, may be directly connected to the carbon nanotube film 120 instead of the frame-shaped member 140. In this case, the carbon nanotube self-standing film 125 can be used as a pellicle when it is formed on the frame-shaped member 190, and the manufacturing process can be simplified.

The method for producing a pellicle membrane according to a preferred embodiment of the present invention has been described above. However, these are merely examples, and the technical scope of the present invention is not limited thereto. In fact, a person skilled in the art will be able to make various modifications without departing from the gist of the invention claimed in the claims. Therefore, it should be understood that those changes naturally belong to the technical scope of the present invention.

Hereinafter, one embodiment of the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

(Manufacturing and evaluation of self-supporting carbon nanotube film of Example 1)
First, a dispersion liquid (concentration 1%) in which carbon nanotubes were dispersed was applied onto an 8-inch silicon substrate by a spin coating method and dried to prepare a silicon substrate on which a carbon nanotube film having a thickness of 40 nm was formed. Next, the first frame-shaped member (jig) is attached to the carbon nanotube film using an epoxy adhesive, and the first frame-shaped member (jig) is connected to the carbon nanotube film formed on the substrate. did. Next, dry etching was performed on the silicon substrate using XeF ₂ gas for 10 minutes. Next, after the second frame-shaped member was attached to the working device, a fluororesin member for generating static electricity was placed on the upper part of the working device to charge the second frame-shaped member. Next, the second frame-shaped member was brought close to the substrate together with the working apparatus, and then separated from the substrate. At this time, a part of the carbon nanotube film was attracted to the second frame-shaped member by static electricity and separated, and the carbon nanotube self-standing film was formed. No wrinkles were observed in the carbon nanotube free-standing film formed by the above method.

(Manufacturing and evaluation of self-supporting carbon nanotube film of Example 2)
First, a silicon oxide film having a thickness of 100 nm was previously formed on an 8-inch silicon substrate by a plasma CVD method as a sacrificial layer, and a dispersion liquid (concentration 1%) in which carbon nanotubes were dispersed was applied by a spin coating method. A silicon substrate on which a carbon nanotube film having a thickness of 40 nm was formed was prepared by coating and drying. Next, the first frame-shaped member (jig) is attached to the carbon nanotube film using an epoxy adhesive, and the first frame-shaped member (jig) and the carbon nanotube film formed on the substrate are attached. Connected. Next, dry etching was performed on the silicon oxide film with HF gas for 15 minutes. Next, after attaching the second frame-shaped member to the work equipment, a fluororesin member for generating static electricity is charged on the upper part of the work equipment, the second frame-shaped member is brought close to the substrate together with the work equipment, and then separated from the substrate. did. At this time, a part of the carbon nanotube film was attracted to the second frame-shaped member by static electricity and separated, and when visually confirmed, the carbon nanotube film was connected to the frame and the carbon nanotube self-standing film was formed. No wrinkles were observed in the carbon nanotube free-standing film formed by the above method.

(Manufacturing and evaluation of self-supporting carbon nanotube film of Comparative Example 1)
First, a silicon oxide film was formed on the back surface of an 8-inch silicon substrate as an etching mask material with a thickness of 100 nm. The silicon oxide film was formed in a rectangular shape so as to surround the periphery of the silicon substrate where the carbon nanotubes are to become a self-supporting film (hereinafter, also referred to as “window”). A carbon nanotube film having a thickness of 40 nm was formed on the surface of the silicon substrate by applying a dispersion liquid (concentration 1%) in which carbon nanotubes were dispersed onto the silicon substrate by a spin coating method and drying the mixture. Next, spin etching was performed from the back surface of the silicon substrate using a so-called mixed acid of hydrofluoric acid and nitric acid, and an attempt was made to etch the silicon substrate in the window portion and to form a self-supporting film of carbon nanotubes. The window portion of the silicon substrate was removed by wet etching for 3 hours, but the carbon nanotube film was broken by the impact of the etching, and the carbon nanotube self-standing film could not be obtained.

From the above, by using one embodiment of the present invention, a carbon nanotube self-standing film can be stably produced.

110 ... substrate, 115 ... sacrificial layer, 120 ... carbon nanotube film, 125 ... carbon nanotube self-standing film, 128 ... adhesive, 130 ... frame-shaped member, 137 ... gas , 140 ... Frame-shaped member, 145 ... Adhesive, 150 ... Working equipment, 160 ... Charging member, 180 ... Pellicle film, 185 ... Adhesive, 190 ... Frame-shaped Members, 195 ... pellicle frame, 200 ... pellicle, 280 ... exposure device, 281 ... exposure original plate, 282 ... light source, 283 ... illumination optical system, 284 ... original plate, 285 ... Filter window, 286 ... Filter window, 287 ... Sensitive substrate, 288 ... Projection optics, 289 ... Multi-walled film mirror, 290 ... Multi-walled film mirror, 291 ... Multi-walled film mirror

Claims (13)

A carbon nanotube film is formed on the first surface and the first surface of the substrate having the second surface on the opposite side of the first surface.
The carbon nanotube film and the first frame-shaped member are connected to each other.
The substrate is dry-etched from the first surface side.
Separating the carbon nanotube film from the substrate,
Method for manufacturing carbon nanotube self-supporting film. The dry etching is performed using an etching gas having an etching rate of the substrate in the range of 0.01 μm / min or more and 10 μm / min or less.
The method for producing a self-supporting carbon nanotube film according to claim 1. The substrate has a sacrificial layer on the first surface side.
The carbon nanotube film is formed on the sacrificial layer, and the carbon nanotube film is formed on the sacrificial layer.
The sacrificial layer is removed by the dry etching.
The method for producing a self-supporting carbon nanotube film according to claim 1 or 2. The sacrificial layer comprises at least one selected from the group consisting of polycrystalline silicon, amorphous silicon, silicon oxide, and aluminum.
The method for producing a self-supporting carbon nanotube film according to claim 3. The dry etching uses at least one gas of XeF ₂ gas or HF gas.
The method for producing a carbon nanotube free-standing film according to any one of claims 1 to 4. The thickness of the carbon nanotube film is 10 nm or more and 200 nm or less.
The method for producing a carbon nanotube free-standing film according to any one of claims 1 to 5. When separating the carbon nanotube film, a second frame-shaped member smaller than the first frame-shaped member is connected to the carbon nanotube film, and the second frame-shaped member is moved in a direction away from the substrate.
The method for producing a carbon nanotube free-standing film according to any one of claims 1 to 6. The carbon nanotube film and the second frame-shaped member are connected via a van der Waals force.
The method for producing a self-supporting carbon nanotube film according to claim 7. Before connecting the carbon nanotube film and the second frame-shaped member, static electricity is applied to the second frame-shaped member.
The method for producing a self-supporting carbon nanotube film according to claim 8. Before connecting the carbon nanotube film and the second frame-shaped member, the charged member charged to the second frame-shaped member is brought close to the carbon nanotube film.
The method for producing a self-supporting carbon nanotube film according to claim 9. The volume resistivity of the charging member is 10 ¹⁴ Ω · cm or more.
The method for producing a self-supporting carbon nanotube film according to claim 10. The second frame-shaped member and the carbon nanotube film are adhered to each other using an adhesive.
The method for producing a self-supporting carbon nanotube film according to claim 7. The carbon nanotube free-standing film according to any one of claims 7 to 12 is used as a pellicle film.
The pellicle film and the third frame-shaped member smaller than the second frame-shaped member are connected.
How to make a pellicle.

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