JP2019168502A - Manufacturing method of carbon nanotube self-supporting film and manufacturing method of pellicle - Google Patents

Abstract

To provide a manufacturing method for stably manufacturing a carbon nanotube self-supporting film.SOLUTION: There is provided a manufacturing method of a carbon nanotube self-supporting film 125 for forming a carbon nanotube film on a first surface of a substrate having the first surface and a second surface on an opposite side of the first surface, connecting the carbon nanotube film and a first frame shape member, dry etching the substrate from the first surface side, and separating the carbon nanotube film from the substrate. In the manufacturing method of the carbon nanotube self-supporting film, dry etching may be performed by using an etching gas having etching rate of the substrate in a range of 0.01 to 10 μm/min.SELECTED DRAWING: Figure 10

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 dust-proof cover for exposure original plate that prevents dust from adhering. The pellicle and the like. In particular, the present invention relates to a method for producing a carbon nanotube free-standing film used as a pellicle film, which is an ultra-thin film for extreme ultraviolet (EUV) lithography, and a method for producing a pellicle.

  In a manufacturing process of a semiconductor device such as a large scale integrated circuit (LSI) or VLSI, a liquid crystal display panel, or the like, patterning is performed by irradiating light to a photosensitive layer or the like through a mask (also called an exposure original plate or a reticle). At this time, if a foreign substance adheres to the mask, the light is absorbed by the foreign substance, or the light is reflected by the surface of the foreign substance and bent. As a result, there is a problem that the pattern to be formed is deformed or the edge is stuck, and the dimension, quality, appearance and the like after patterning are impaired. In order to solve such a problem, a method is adopted in which a pellicle having a pellicle film that transmits light is attached to the surface of the mask to suppress adhesion of foreign matter.

  The wavelength of light used for lithography is becoming shorter, and the use of EUV light as a next-generation lithography technique is being studied. EUV light refers to light having a wavelength in the soft X-ray region or the vacuum ultraviolet region, and specifically refers to light 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 the pellicle film may be damaged by heat generated by the energy of the EUV light. Therefore, it is considered that a conventional pellicle film for ArF light, for example, is not suitable for EUV light.

  The pellicle film of the EUV pellicle is usually manufactured by laminating silicon nitride (SiN) or the like on a silicon wafer substrate. On the other hand, development of a pellicle using a carbon nanotube film as a material having high transparency to EUV light and high resistance to EUV is being promoted. Patent Document 1 and Patent Document 2 disclose a pellicle for EUV 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 manufacture a self-supporting film (referred to as a film that does not have a support member on any surface).

  In view of such a problem, an embodiment of the present invention aims to stably manufacture a carbon nanotube free-standing film. Another object of the present invention is to stably manufacture a pellicle using a carbon nanotube free-standing film.

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

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

  In the method for producing a carbon nanotube free-standing 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 manufacturing a carbon nanotube free-standing film, the sacrificial layer may include at least one of polycrystalline silicon, amorphous silicon, silicon oxide, and aluminum.

In the method for producing a carbon nanotube free-standing film, dry etching may use at least one of XeF ₂ gas and HF gas.

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

  In the carbon nanotube self-supporting film manufacturing method, when separating the carbon nanotube film, a second frame member smaller than the first frame member is connected to the carbon nanotube film, and the second frame member is moved away from the substrate. It may be moved.

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

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

  In the method for manufacturing a carbon nanotube self-supporting film, a charged member charged to the second frame member may be brought close to the second frame member before connecting the carbon nanotube film and the second frame member.

In the method for producing a carbon nanotube free-standing film, the charging member may have a volume resistivity of 10 ¹⁴ Ω · cm or more.

  In the carbon nanotube self-supporting film manufacturing method, the second frame-shaped member and the carbon nanotube film may be bonded using an adhesive.

  According to an embodiment of the present invention, there is provided a method for manufacturing a pellicle, wherein the carbon nanotube free-standing film is used as a pellicle film, and the pellicle film is connected to a third frame-shaped member that is smaller than the second frame-shaped member. The

  According to one embodiment of the present invention, an exposure original plate including an 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. There is provided a method for manufacturing a semiconductor device, in which an original plate is irradiated, reflected by the original plate, and light reflected by the original plate is transmitted through a pellicle film to irradiate the sensitive substrate to expose the sensitive substrate in a pattern.

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

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

It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the pellicle which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the pellicle which concerns on one Embodiment of this invention. It is the upper side figure and sectional drawing of the pellicle which concern 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 the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention. It is the top view and sectional drawing which show the manufacturing method of the carbon nanotube self-supporting film | membrane which concerns on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different modes and should not be construed as being limited to the description of the embodiments exemplified below. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with actual aspects for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited. It is not limited. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate.

  In this specification, when a member or region is “on (or below)” another member or region, this is directly above (or directly below) the other member or region unless otherwise specified. ) As well as the case above (or below) other members or regions, i.e., another component is included above (or below) other members or regions. Including cases.

  In this specification, EUV light refers to light having a wavelength of 5 nm to 30 nm. Note that the wavelength of the EUV light is preferably 5 nm or more and 14 nm or less, and specifically, the EUV light indicates light of about 13.5 nm ± 0.3 nm.

  In this specification, trimming means cutting the substrate or the substrate and the pellicle film formed thereon according to a desired shape of the pellicle. Since the shape of the pellicle is mostly rectangular, this specification shows an example of cutting into a rectangular shape as a specific example of trimming.

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

(1-1-1. 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), but may be a semiconductor material such as germanium (Ge), silicon germanium (SiGe), silicon carbide (SiC), gallium arsenide (GaAs), or a quartz glass substrate (oxidized). Silicon substrates (SiO ₂ ), soda glass substrates, borosilicate glass substrates, sapphire substrates, silicon nitride (SiN), aluminum nitride (AlN) substrates, zirconia (ZrO ₂ ) substrates, aluminum oxide (Al ₂ O ₃₎ ) Etc. The substrate 110 preferably contains at least one of silicon, sapphire, and silicon carbide having a linear thermal expansion coefficient close to that of the pellicle film in order to reduce thermal strain with the carbon nanotube film 120. 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 (which may be a carbon nanotube bulk structure) used in this 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 what was formed on the base material. As the CVD method, for example, a plasma CVD method is used, but a low pressure 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 10,000 ppm or less, and water vapor may be added in a temperature environment of 600 ° C. or more and 1000 ° C. or less. Alternatively, a carbon catalyst may be synthesized by arranging or patterning a metal catalyst on a chemical vapor deposition substrate. The obtained carbon nanotubes may be single-walled or multi-walled, and may be carbon nanotubes standing in a direction perpendicular to the surface of the chemical vapor deposition substrate. In detail, it can manufacture, for example with reference to international publication 2006/011655 etc. Examples of such commercially available carbon nanotubes include carbon nanotubes manufactured by Nippon Zeon Co., Ltd., manufactured by Super Growth.

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

  Carbon nanotubes (or a carbon nanotube bulk structure) obtained by a CVD method and an e-DIPS method 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) in which carbon nanotubes (or a carbon nanotube bulk structure) are dispersed on the substrate 110 and evaporating and removing the solvent. In the present embodiment, by removing the solvent used in the dispersion, a film in which the carbon nanotubes are substantially parallel to the first surface 110-1 of the substrate 110 is obtained (that is, the first surface 110- It can also be said that there are few carbon nanotubes standing in a direction perpendicular to 1. The coating method is not particularly limited, and for example, spin coating, dip coating, bar coating, spray coating, electrospray coating, or the like may be used. The metal catalyst used to form the carbon nanotubes may cause a decrease in EUV transmittance. However, when the carbon nanotubes are peeled off from the chemical vapor deposition substrate, the carbon nanotubes contain almost no metal catalyst. There is no effect because there is no.

  The thickness of the carbon nanotube film 120 obtained by the above-described method is 10 nm to 200 nm, preferably 10 nm to 100 nm, more preferably 10 nm to 70 nm, still more preferably 10 nm to 50 nm, and most preferably 10 nm to 45 nm. It is desirable that

  Moreover, the diameter of the carbon nanotube 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 nanotube is 10 μm or more and 10 cm or less, and the carbon content in the carbon nanotube is 98 mass%. The above is desirable.

(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 a first frame-shaped member) are connected. A material different from that of the substrate 110 is used for the frame 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 made of a metal material such as brass, aluminum, an aluminum alloy (5000 series, 6000 series, 7000 series, etc.), copper, or an organic resin such as a fluororesin, an acrylic resin, or an epoxy resin. Materials, ceramic materials such as boron nitride, silicon nitride, aluminum oxide, and graphite may be used. 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 rectangular, polygonal, or annular, for example.

  Further, when the carbon nanotube film 120 and the frame member 130 are connected, an adhesive 128 may be used. The adhesive 128 may be in the form of a film or may be used by curing a liquid material. 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 dry etching 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 a network in the plane, and has a large number of voids. Since the void is sufficiently larger than the reactive gas used in the dry etching method, the reactive gas can permeate the carbon nanotube film and cause the substrate and the reactive gas to react. Therefore, by using the dry etching method, only the substrate 110 can be etched without etching the carbon nanotube film 120. At this time, the portion 110A of the substrate 110 that overlaps the frame member 130 remains without being removed because the frame 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 kept apart from each other without being recontacted. Note that 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. From the viewpoint of preventing the re-contact between the carbon nanotube film 120 and the substrate 110 while leaving the overlapping portion 110A and the viewpoint of the handleability of the frame-shaped member 130, the width of the frame-shaped member 130 is preferably 0.1 mm or more and 50 mm or less. . Moreover, from the viewpoint of the strength of the frame-shaped member 130 and the viewpoint of handleability, 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 the carbon nanotubes. Further, a gas capable of etching the substrate 110 is used as the gas 137 used in the dry etching method. 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 perform using an etching gas whose etching rate of the substrate 110 is in the range of 0.01 μm / min to 10 μm / min. Here, the damage to the carbon nanotubes includes cutting and alteration of the carbon nanotubes themselves with an etching gas. When the etching time of the substrate 110 becomes long and the etching gas reacts with carbon, the carbon-carbon bond is broken, and the length of the carbon nanotube is shortened or a hole is opened in the carbon nanotube film 120 in some cases. When the length of the carbon nanotube is shortened, the strength of the carbon nanotube film 120 cannot be maintained, or the crystallinity of the carbon nanotube may be lowered. Alternatively, if the carbon nanotube film 120 has a hole, it may not be able to have dust resistance as a pellicle film. Therefore, by etching the substrate 110 at the above-described etching rate, damage to the carbon nanotube can be reduced. Specifically, the etching time of the substrate 110 is desirably 1 hour or less, preferably within 30 minutes, and more preferably within 20 minutes.

A specific example of the etching gas is not particularly limited as long as the substrate 110 can be etched. For example, F ₂ , CF ₄ , C ₄ F ₈ , CHF ₃ , XeF ₆ , XeF ₂ , SF ₆ , O ₂ , O ₃ , H _{2 can be used.} 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 as the substrate 110 by a dry etching method, specifically, a gas such as XeF ₂ , SF ₆ , CF _4, or C ₄ F ₈ is used. Among these, XeF ₂ has a high etching rate of the silicon substrate, and can shorten the etching time of the substrate 110. Therefore, it is desirable because damage to the carbon nanotube film 120 can be reduced.

Or, as the substrate 110, the case of using a quartz glass substrate including silicon oxide (SiO _2), hydrogen fluoride _{(HF), SF 6, CHF} 3 or C ₄ F ₈ and hydrogen (H ₂₎ gas, such as is used . Among 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 damage to the carbon nanotube film 120 can be reduced.

(1-1-4. Separation of carbon nanotube film)
Next, as shown in FIG. 4, a 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 machine tools 150. A material similar to that of 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 a top view.

Next, as shown in FIG. 5, the charging member 160 is arranged on the machine tool 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 a fluororesin, an acrylic resin, or a polycarbonate is used. These insulating materials are charged by contact charging or peeling charging, 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. In addition, when the machine tool 150 is sufficiently charged, the charging member 160 can be omitted. In addition, the charging member 160 may be installed on the machining device 150 in advance before the frame-shaped member 140 is superimposed on the carbon nanotube film 120.

  Next, as shown in FIG. 6, the machine tool 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 through van der Waals force generated by the bias of electric charge. The charging member 160 may be installed on the machine tool 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 charge amount. Specifically, an apparatus 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 machining 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. Of the manufactured carbon nanotube free-standing film 125, the outer portion of the frame-shaped member 140 may be removed by trimming as appropriate.

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

  First, as shown in FIG. 8, a frame-shaped member 190 (also referred to as a third frame-shaped member) and a carbon nanotube free-standing film 125 are overlapped. The frame-shaped member 190 is smaller than the frame-shaped member 140 in a top view. The frame member 190 is used as a pellicle frame 195. Therefore, a known pellicle frame can be used as the frame-shaped member 190. The material of the frame member 190 is not particularly limited, but aluminum or aluminum alloy (5000 series, 6000 series, 7000 series, etc.), stainless steel, titanium, silicon, and the like are preferable from the viewpoint of achieving both lightness and strength. A material having resistance to EUV may be provided on the surface of the frame-shaped member 190. Specifically, a material containing one or more elements selected from Mo, Ru, and B can be given. Further, at this time, alcohol 190 such as isopropyl alcohol or water may adhere to a portion 190A of the frame-shaped member 190 that contacts the carbon nanotube free-standing film 125. In addition, 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 free-standing 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 free-standing film 125 is separated from the frame-shaped member 140. Thus, the pellicle 200 is manufactured as shown in FIG. The carbon nanotube free-standing film 125 is used as the pellicle film 180. In addition, since the manufactured pellicle for EUV has a limit on the height of the pellicle, the total height 10h 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 become.

  Thereafter, other processes such as trimming the carbon nanotube free-standing film 125 or coating with an adhesive 185 may be performed.

(1-3. Use of pellicle)
The pellicle of this embodiment can be used as an exposure original by being mounted on the original. The pellicle of this embodiment is not only used as a protective member for suppressing foreign matter from adhering to the original in the EUV exposure apparatus, but also for protecting the original when the original is stored or transported. It may be used as a member. For example, if the pellicle is mounted on the original (exposure original), it can be stored as it is after being removed from the EUV exposure apparatus. As a method of mounting the pellicle on the original plate, there are a method of attaching with a bonding agent, an electrostatic adsorption method, a method of mechanically fixing, and the like.

  Here, as the original plate, an original plate that includes a support substrate, a reflective layer laminated on the support substrate, and an absorber layer formed on the reflective layer may be used. The absorber layer partially absorbs EUV light, whereby a desired image is formed on a 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 absorbability such as EUV light, such as chromium (Cr) or tantalum nitride.

(1-4. Exposure apparatus)
Hereinafter, an exposure apparatus using the exposure original plate including the pellicle manufactured in the present embodiment will be described. FIG. 11 is a schematic cross-sectional view of an EUV exposure apparatus 280 that 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 the 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 condensed by the illumination optical system 283, and the illuminance is made uniform, and the exposure original plate 281 is irradiated. The EUV light irradiated on the exposure original plate 281 is reflected in a pattern by the original plate 284.

  The exposure original plate 281 is an example of an exposure original plate according to this embodiment. That is, a pellicle 200 which is an example of a pellicle of this embodiment including a pellicle film 180 and a pellicle frame 195 and an original 284 are provided. The exposure original plate 281 is arranged so that EUV light emitted from the light source 282 passes through the pellicle film 180 and is irradiated onto 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 (optical integrator), and the like.

  As the light source 282 and the illumination optical system 283, a known light source and illumination optical system 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 284, respectively. The filter windows 285 and 286 are capable of capturing scattered particles (debris). In addition, the EUV exposure apparatus 280 includes a projection optical system 288 that guides the EUV light reflected by the original 284 to the sensitive substrate 287. In the EUV exposure apparatus 280, the EUV light reflected by the original 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. Note that 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, a known projection optical system can be used.

  The sensitive substrate 287 is a substrate on which a resist is coated on a semiconductor wafer, and the resist is cured in a pattern by the EUV light reflected by the original 284. The resist is developed, and the semiconductor wafer is etched to form a desired pattern on the semiconductor wafer.

  As described above, the exposure apparatus 280 uses the exposure original plate including the original plate and the pellicle manufactured in this embodiment mounted on the surface having the pattern of the original plate, and emits the light emitted from the light source to the pellicle film. The sensitive substrate can be exposed in a pattern by passing through and irradiating the original, reflecting off the original, and irradiating the sensitive substrate with the light reflected by the original through the pellicle film. A semiconductor device is manufactured by appropriately combining this process and the etching process.

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

Second Embodiment
In the present embodiment, a method for producing a carbon nanotube free-standing film different from that in the first embodiment will be described. In addition, about the material and method similar to 1st Embodiment, the description is used.

  In the present 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 that is removed by a dry etching method. The material of the sacrificial layer 115 is not particularly limited, but is preferably a material having 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, Organic insulating materials 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 as the substrate 110, a silicon oxide film formed by a plasma CVD method may be used as the sacrificial layer 115. The thickness of the sacrificial layer 115 is 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 changed as appropriate depending on 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 perform dry etching using HF gas. When the HF gas is used, the etching rate of the silicon oxide film 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 a xenon fluoride (XeF ₂ ) gas. When XeF ₂ gas is used, the etching rate of the polycrystalline silicon film is 0.01 μm / min or more and 10 μm / min or less.

Alternatively, when an aluminum (Al) film is etched as the sacrificial layer 115 by a dry etching method, any gas 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, the example in which the frame-shaped member 140 and the carbon nanotube film 120 are connected and separated is shown, but the present invention is not limited to this. For example, when the frame-shaped member 140 is brought close to the carbon nanotube film 120, the carbon nanotube film 120 may be attracted by electrostatic attraction to partially separate the carbon nanotube free-standing film 125 and the frame-shaped member 140.

(Modification 2)
In the first embodiment of the present invention, an example in which static electricity is applied to the frame-shaped member 140 and the carbon nanotube film 120 is connected to the carbon nanotube film 120 by van der Waals force has been described, but the present invention is not limited thereto. For example, as shown in FIG. 14, the frame 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 used after curing a liquid. 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, the carbon nanotube self-supporting film and the pellicle manufacturing method using the frame-shaped member 130, the frame-shaped member 140, and the frame-shaped member 190 have been described. However, the present invention is not limited to this. For example, the frame-shaped member 190 that 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 free-standing film 125 can be used as a pellicle when it is formed on the frame-like member 190, and the manufacturing process can be simplified.

  In the above, the manufacturing method of the pellicle film by preferable embodiment of this invention was demonstrated. However, these are merely examples, and the technical scope of the present invention is not limited thereto. Indeed, various modifications will be apparent to those skilled in the art without departing from the spirit of the invention as claimed in the claims. Therefore, it should be understood that these changes also belong to the technical scope of the present invention.

  Hereinafter, although one Embodiment of this invention is described more concretely based on an Example, this invention is not limited to these Examples at all.

(Production and evaluation of carbon nanotube free-standing film of Example 1)
First, a silicon substrate on which a carbon nanotube film having a thickness of 40 nm was formed was prepared by applying a dispersion liquid (concentration: 1%) in which carbon nanotubes were dispersed onto an 8-inch silicon substrate by spin coating and drying. Next, a first frame member (jig) is attached to the carbon nanotube film using an epoxy adhesive, and the first frame member (jig) is connected to the carbon nanotube film formed on the substrate. did. Next, dry etching was performed for 10 minutes on the silicon substrate using XeF ₂ gas. Next, after attaching the second frame-shaped member to the machine tool, a member made of fluororesin for generating static electricity was arranged on the upper part of the machine device to charge the second frame-shaped member. Next, the second frame-shaped member was brought close to the substrate together with the machine tool, and then separated from the substrate. At this time, a part of the carbon nanotube film was attracted to and separated from the second frame member by static electricity, and a carbon nanotube self-supporting film was formed. In addition, wrinkles were not recognized in the carbon nanotube free-standing film formed by the above method.

(Production and evaluation of carbon nanotube free-standing film of Example 2)
First, a silicon oxide film having a thickness of 100 nm as a sacrificial layer is previously formed on an 8-inch silicon substrate by plasma CVD, and a dispersion liquid (concentration 1%) on which carbon nanotubes are dispersed is formed by spin coating. By applying and drying, a silicon substrate on which a carbon nanotube film having a thickness of 40 nm was formed was prepared. Next, the first frame member (jig) is attached to the carbon nanotube film using an epoxy adhesive, and the first frame member (jig) and the carbon nanotube film formed on the substrate are bonded. Connected. Next, dry etching was performed on the silicon oxide film with HF gas for 15 minutes. Next, after attaching the second frame member to the machine tool, the upper part of the machine device is charged with a fluororesin member for generating static electricity, and the second frame member is brought close to the substrate together with the machine device, and then separated from the substrate. did. At this time, a part of the carbon nanotube film was attracted to and separated from the second frame-like member by static electricity and visually confirmed. As a result, the carbon nanotube film was connected to the frame, and a carbon nanotube self-supporting film was formed. In addition, wrinkles were not recognized in the carbon nanotube free-standing film formed by the above method.

(Production and evaluation of carbon nanotube free-standing film of Comparative Example 1)
First, a silicon oxide film having a thickness of 100 nm was formed as an etching mask material on the back surface of an 8-inch silicon substrate. The silicon oxide film was formed in a rectangular shape so as to surround a portion of the silicon substrate where the carbon nanotubes were to become self-supporting films (hereinafter also referred to as “windows”). On the surface of the silicon substrate, a carbon nanotube film having a thickness of 40 nm was formed by applying a dispersion liquid (concentration 1%) in which carbon nanotubes were dispersed on the silicon substrate by spin coating and drying. 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 make a carbon nanotube free-standing film. Although the window portion of the silicon substrate was removed by wet etching for 3 hours, the carbon nanotube film was broken by the impact of etching, and a carbon nanotube free-standing film was not obtained.

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

  DESCRIPTION OF SYMBOLS 110 ... Substrate, 115 ... Sacrificial layer, 120 ... Carbon nanotube film, 125 ... Carbon nanotube free-standing film, 128 ... Adhesive, 130 ... Frame member, 137 ... Gas , 140 ... frame member, 145 ... adhesive, 150 ... machine tool, 160 ... charging member, 180 ... pellicle film, 185 ... adhesive, 190 ... frame shape 195 ... pellicle frame, 200 ... pellicle, 280 ... exposure device, 281 ... exposure original, 282 ... light source, 283 ... illumination optical system, 284 ... original, 285 ... Filter window, 286 ... Filter window, 287 ... Sensitive substrate, 288 ... Projection optical system, 289 ... Multilayer mirror, 290 ... Multilayer mirror, 291 ... Multilayer film Over

Claims (15)

Forming a carbon nanotube film on the first surface of the substrate having a first surface and a second surface opposite to the first surface;
Connecting the carbon nanotube film and the first frame member;
Dry etching the substrate from the first surface side;
Separating the carbon nanotube film from the substrate;
A method for producing a carbon nanotube free-standing film. The dry etching is performed using an etching gas in which the etching rate of the substrate is in the range of 0.01 μm / min to 10 μm / min.
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 1. The substrate has a sacrificial layer on the first surface side,
The carbon nanotube film is formed on the sacrificial layer,
Removing the sacrificial layer by the dry etching;
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 1 or 2. The sacrificial layer includes at least one selected from the group consisting of polycrystalline silicon, amorphous silicon, silicon oxide, and aluminum.
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 3. The dry etching uses at least one gas of XeF ₂ gas or HF gas,
The manufacturing method of the carbon nanotube self-supporting film | membrane as described in any one of Claims 1 thru | or 4. The carbon nanotube film has a thickness of 10 nm to 200 nm.
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 away from the substrate.
The manufacturing method of the carbon nanotube self-supporting film | membrane as described in any one of Claims 1 thru | or 6. Connecting the carbon nanotube film and the second frame member via van der Waals force;
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 7. Applying static electricity to the second frame member before connecting the carbon nanotube film and the second frame member;
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 8. Before connecting the carbon nanotube film and the second frame-shaped member, a charged charging member is brought close to the second frame-shaped member;
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 9. The charging member has a volume resistivity of 10 ¹⁴ Ω · cm or more.
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 10. Bonding the second frame-shaped member and the carbon nanotube film using an adhesive;
The manufacturing method of the carbon nanotube self-supporting film | membrane of Claim 7. Using the carbon nanotube free-standing film according to any one of claims 7 to 12 as a pellicle film,
Connecting the pellicle film and a third frame member smaller than the second frame member;
Pellicle manufacturing method. An exposure original plate comprising: an original plate; and a pellicle according to claim 13 attached to a surface on the side having the pattern of the original plate,
The light emitted from the light source is transmitted through the pellicle film to irradiate the original, and reflected by the original,
Irradiating the sensitive substrate with the light reflected by the original plate through the pellicle film to expose the sensitive substrate in a pattern,
A method for manufacturing a semiconductor device.   The method of manufacturing a semiconductor device according to claim 14, wherein the light is EUV light.

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