JP2016081957A - Imprint mold substrate, and manufacturing method for imprint mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an imprint mold substrate having a concave part with a predetermined accuracy.SOLUTION: An imprint mold substrate comprises: a thin plate part 2 that has a first surface 2A to which a fine uneven pattern is formed and a second surface 2B opposite to the first surface 2A; and a supporting part 3 of a hollow cylindrical that has a supporting surface 3A supporting the second surface 2B of the thin plate part 2. A method for manufacturing the imprint mold substrate 1 in which the thin plate part 2 and the supporting part 3 are connected so as to block an opening one end of the supporting part 3 of hollow cylindrical with the second surface 2B of thin plate part, includes: a surface activation process of activating the surface of the second surface 2B of thin plate part 2 and/or the supporting surface 3A of supporting part 3 supporting surface 3A; and a connecting process of connecting the second surface 2B of thin plate part 2 with the supporting surface 3A of supporting part 3 so as to block the opening one end of supporting part 3 with the second surface 2B of thin plate part 2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an imprint mold substrate and a method for manufacturing the imprint mold.

  Nanoimprint technology as a microfabrication technology uses a mold member (imprint mold) in which a fine concavo-convex pattern is formed on the surface of a substrate, and transfers the fine concavo-convex pattern onto a workpiece such as an imprint resin. This is a pattern formation technique for transferring a fine concavo-convex pattern at an equal magnification (see Patent Document 1). In particular, with the progress of further miniaturization of wiring patterns and the like in semiconductor devices, nanoimprint technology is gaining more and more attention in semiconductor device manufacturing processes and the like.

  In such a nanoimprint technique, a strong force is required to peel off the imprint mold from a state where the imprint mold and the imprint resin as a workpiece are in close contact with each other. Therefore, when the imprint mold is peeled off, the fine uneven pattern transferred to the imprint resin or the imprint mold may be destroyed.

  Conventionally, in order to solve such a problem, an imprint having a concave portion formed so that a recess becomes deeper from the outer edge portion of the substrate toward the central portion of the substrate on the surface facing the surface on which the fine unevenness pattern is formed. A mold has been proposed (see Patent Document 2).

US Pat. No. 5,772,905 JP 2009-170773 A

  In the imprint mold disclosed in Patent Document 2, the imprint mold has a concave portion on the surface facing the surface on which the fine concavo-convex pattern is formed, so that the imprint mold is peeled off from the imprint resin. Can be bent, and an effect that mold release is possible with a smaller force is exhibited.

  However, the technology for processing and forming the concave portion for making the imprint mold bendable is a very advanced technology. Because, when forming a recess that can bend the imprint mold to the extent that the desired release performance can be obtained by machining using a cutting tool or the like, control the thickness of the bottom of the recess, surface finish, etc. The difficulty of processing is very high. Therefore, it takes time to manufacture the imprint mold having the intended concave shape, which may cause a problem of yield. Moreover, expensive capital investment for manufacturing the imprint mold which has the said recessed part is needed.

  In view of the above problems, an object of the present invention is to provide a substrate for imprint mold having a concave portion with a desired accuracy and a method for manufacturing the imprint mold.

  In order to solve the above problems, the present invention provides a thin plate portion having a first surface on which a fine unevenness pattern can be formed and a second surface facing the first surface, and a support for supporting the second surface of the thin plate portion. A hollow cylindrical support portion having a surface, and the thin plate portion and the support portion are joined so that one end of the opening of the hollow cylindrical support portion is closed by the second surface of the thin plate portion. A surface activation step of activating the second surface of the thin plate portion and / or the surface of the support surface of the support portion, and one opening end of the support portion. A method of manufacturing an imprint mold substrate, comprising: a bonding step of bonding the second surface of the thin plate portion and the support surface of the support portion so as to be blocked by the second surface of the thin plate portion. (Invention 1).

  According to the said invention (invention 1), the opening end of a hollow cylindrical support part is made into the 2nd surface of a thin plate part by activating the 2nd surface of a thin plate part, and / or the surface of the support surface of a support part. Since the thin plate portion and the support portion are directly joined so as to be closed, an imprint mold substrate having a highly accurate recess can be manufactured.

  Further, as a method of directly joining the thin plate portion and the support portion, anodic bonding, hydrofluoric acid bonding, diffusion bonding, etc. can be considered, but according to these methods, the thin plate portion and the support portion are brought into contact with each other at a high temperature. Since it is necessary to heat to about 700 degreeC or to pressurize, there exists a possibility that distortion etc. may arise in the thin-plate part after joining. In particular, depending on the atmosphere at the time of heating, the surface state of the first surface and the second surface of the thin plate portion changes, and the imprint produced from the imprint mold substrate formed by joining the thin plate portion and the support portion. When the mold is used for optical imprint processing, the optical characteristics of the imprint mold may be deteriorated. However, according to the above invention (Invention 1), since the thin plate portion and the support portion are directly joined by activating the second surface of the thin plate portion and / or the surface of the support surface of the support portion, excessive heating is performed. In addition, it is possible to prevent the thin plate portion from being distorted and the optical characteristics from being lowered.

  In the said invention (invention 1), it is preferable to further include the etching process which etches the part exposed through the said support part among the 2nd surfaces of the said thin-plate part (invention 2), and the said thin-plate part is quartz. It is preferably a glass substrate, a sapphire substrate, or a calcium fluoride substrate (Invention 3).

  In the said invention (invention 1-3), in the said surface activation process, those surfaces are activated by exposing the 2nd surface of the said thin-plate part and / or the support surface of the said support part to a plasma atmosphere. (Invention 4).

  In the said invention (invention 4), in the said joining process, by heating to 200-300 degreeC in the state which contacted the 2nd surface of the said thin plate part, and the support surface of the said support part, the 2nd surface of the said thin plate part was obtained. It is preferable to join two surfaces and the support surface of the said support part (invention 5).

  In the said invention (invention 1-3), in the said surface activation process, those surfaces are activated by irradiating the 2nd surface of the said thin-plate part, and / or the support surface of the said support part with an ion beam. (Invention 6).

  Moreover, this invention forms a fine uneven | corrugated pattern in the 1st surface side of the said thin-plate part of the said substrate for imprint molds manufactured by the manufacturing method of the substrate for imprint molds which concerns on the said invention (invention 1-6). The manufacturing method of the imprint mold characterized by including a process is provided (invention 7).

  Furthermore, the present invention includes a thin plate portion having a first surface and a second surface facing the first surface, and a fine uneven pattern formed on the first surface side, and a second surface of the thin plate portion. A hollow cylindrical support portion having a support surface to be supported, and the opening portion of the hollow cylindrical support portion is closed by the second surface of the thin plate portion, and the thin plate portion and the support portion A surface activation step of activating the second surface of the thin plate portion and / or the surface of the support surface of the support portion, and one open end of the support portion. A method of manufacturing an imprint mold, comprising: a joining step of joining the second surface of the thin plate portion and the support surface of the support portion so as to be closed by the second surface of the thin plate portion. Provided (Invention 8)

  Furthermore, the present invention is a hollow having a thin plate portion having a first surface on which a fine concavo-convex pattern can be formed and a second surface facing the first surface, and a support surface supporting the second surface of the thin plate portion. An imprint mold comprising: a cylindrical support portion, wherein the thin plate portion and the support portion are joined so that one end of the opening of the hollow cylindrical support portion is closed by the second surface of the thin plate portion A substrate for imprint molding, wherein the substrate for imprint mold has a high transmittance portion with a high transmittance of light having a wavelength of 400 nm or less in the thickness direction of the thin plate portion, and the transmittance of the light is higher than that of the high transmittance portion. A low low transmittance portion, and the high transmittance portion is constituted by a portion of the thin plate portion exposed by a hollow cylindrical portion of the support portion, and the low transmittance portion is configured by the thin plate portion and the support. Consists of a part including a bonding interface with the part, Serial Overall substrate imprint mold, providing a substrate for imprint mold, wherein the transmittance of the light having the wavelength of 400nm exceeds the thickness direction of the thin portion is substantially constant (invention 9).

  The present invention also includes a thin plate portion having a first surface and a second surface facing the first surface, and a fine uneven pattern formed on the first surface side, and a second surface of the thin plate portion. A hollow cylindrical support portion having a support surface to be supported, and the opening portion of the hollow cylindrical support portion is closed by the second surface of the thin plate portion, and the thin plate portion and the support portion The imprint mold comprises a high transmittance portion having a high transmittance of light having a wavelength of 400 nm or less in the thickness direction of the thin plate portion, and the light transmittance being the high transmittance. A low transmittance part lower than the rate part, and the high transmittance part is constituted by a part of the thin plate part exposed by a hollow cylindrical part of the support part, and the low transmittance part is formed by the thin plate And a portion including a bonding interface between the support portion and the support portion. An auxiliary mark is formed in a portion corresponding to the low transmittance portion of the first surface of the thin plate portion, and the entire imprint mold has a substantial transmittance of light having a wavelength of more than 400 nm in the thickness direction of the thin plate portion. The imprint mold is characterized by being constant (Invention 10).

  ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing the board | substrate for imprint molds and the imprint mold which have a recessed part with the desired precision can be provided.

FIG. 1A is a cut end view showing a schematic configuration of an imprint mold substrate in one embodiment of the present invention, and FIG. 1B is an exploded perspective view showing a schematic configuration of the imprint mold substrate. FIG. FIG. 2 is a process flow diagram showing each step of the method for manufacturing an imprint mold substrate according to the embodiment of the present invention in a cut end view. FIG. 3 is a process flow chart showing each process of the imprint mold manufacturing method according to the embodiment of the present invention in a cut end view. FIGS. 4A and 4B are cut end views schematically showing another configuration example of an imprint mold substrate in one embodiment of the present invention. FIG. 5 is a graph showing the transmittance measurement results in Test Example 1.

Embodiments of the present invention will be described with reference to the drawings.
<Imprint mold substrate>
1A and 1B are a cut end view (FIG. 1A) showing a schematic configuration of an imprint mold substrate 1 manufactured by the method for manufacturing an imprint mold substrate according to the present embodiment; It is a disassembled perspective view (FIG. 1 (B)).

  As shown in FIGS. 1A and 1B, the imprint mold substrate 1 has a first surface 2A on which a fine uneven pattern of the imprint mold can be formed and a second surface 2B facing the first surface 2A. The thin plate portion 2 and the hollow cylindrical support portion 3 that supports the second surface 2B of the thin plate portion 2, and the thin plate portion 2 and the support portion so as to close the opening end 31 of the hollow cylindrical support portion 3. 3 is joined, and it has the recessed part 4 comprised by the 2nd surface 2B of the thin-plate part 2 which obstruct | occludes the opening end 31 and the hollow part 30 of the support part 3. As shown in FIG.

  The imprint mold substrate 1 in the present embodiment has a high transmittance part 1A having a high transmittance (transmittance: 93% or more) of light having a wavelength of 400 nm or less (transmittance of light traveling in the thickness direction of the thin plate portion 2). And a low transmittance portion 1B having a lower transmittance of light having a wavelength of 400 nm or less than that of the high transmittance portion 1A (transmittance: less than 93%). On the other hand, the imprint mold substrate 1 as a whole has substantially the same transmittance of light having a wavelength of more than 400 nm (transmittance of light traveling in the thickness direction of the thin plate portion 2), and is 93% or more. It has transmittance.

  As will be described later, the imprint mold substrate 1 in the present embodiment performs surface activation treatment on the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 (see FIG. 1B). (See FIGS. 2A and 2B). By this surface activation treatment, impurities or the like adhere to the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3, and light of the thin plate portion 2 and the support portion 3 (light having a wavelength of 400 nm or less). The transmittance of light traveling in the thickness direction of the thin plate portion 2 is reduced. Since the imprint mold substrate 1 in the present embodiment is manufactured by performing an etching process after the thin plate portion 2 and the support portion 3 are joined, the hollow portion of the support portion 3 in the second surface 2B of the thin plate portion 2. Impurities and the like attached to the portion exposed through 30 are removed, and the transmittance of light (light having a wavelength of 400 nm or less and traveling in the thickness direction of the thin plate portion 2) in the portion is improved. On the other hand, the transmittance of light having a wavelength of more than 400 nm hardly fluctuates regardless of the presence or absence of such impurities. Therefore, in the imprint mold substrate 1 in the present embodiment, the portion corresponding to the recess 4 (the portion exposed by the hollow portion 30) of the thin plate portion 2 is configured as the high transmittance portion 1A, and the high transmittance portion A portion outside 1A (the support portion 3 and a portion of the thin plate portion 2 joined to the support portion 3) is configured as the low transmittance portion 1B.

  When an imprint mold is produced from the imprint mold substrate 1 in the present embodiment, the fine uneven pattern is formed on the first surface 2A of the thin plate portion 2 of the imprint mold substrate 1 and in the region corresponding to the recess 4. 11 need to be formed. This is because, in the thin plate portion 2, the region corresponding to the recess 4 is a region bent by an external force. Here, the imprint mold substrate 1 in the present embodiment has substantially the same transmittance for light having a wavelength of more than 400 nm as a whole, but has a high transmittance portion 1A having different transmittances for light having a wavelength of 400 nm or less. And a low transmittance part 1B. Therefore, by measuring the transmittance of light (light having a wavelength of 400 nm or less) of the substrate 1 for imprint mold, a region corresponding to the concave portion 4 even from the first surface 2A side of the thin plate portion 2, that is, fine unevenness The region where the pattern 11 is to be formed can be reliably grasped.

<Method for manufacturing substrate for imprint mold>
A method for manufacturing the imprint mold substrate 1 having the above-described configuration will be described below. FIG. 2 is a process flow diagram schematically showing a method for manufacturing an imprint mold substrate according to the present embodiment in a cut end view.

[Surface activation process]
In the present embodiment, first, the thin plate portion 2 and the support portion 3 are prepared, and the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 (the surface contacting the second surface 2B of the thin plate portion 2). A surface activation treatment is performed (see FIG. 2A).

  Examples of the thin plate portion 2 include a glass substrate such as a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, an acrylic glass substrate, and a borosilicate glass substrate; a polycarbonate substrate, a polypropylene substrate, and polyethylene. Substrates, other resin substrates such as polyolefin substrates, single layer substrates made of sapphire substrates, transparent substrates such as laminated substrates formed by laminating two or more arbitrarily selected from the above substrates, and the like can be used.

  In this embodiment, “transparent” means light having a wavelength capable of curing a photocurable resin as an imprint resin, for example, light having a wavelength of 200 to 400 nm. When irradiated from one side of the thin plate portion 2), this means that the light reaches the side opposite to the irradiated side. Since the purpose is to cure the photo-curing resin, it is 60% or more, preferably 90% or more, particularly preferably 96% or more if a suitable standard is shown by transmittance.

  The thickness T2 of the thin plate portion 2 can be appropriately set according to the material of the thin plate portion 2, the use of the imprint mold produced from the imprint mold substrate 1, and the thin plate portion 2 is made of quartz glass. In this case, it can be set to about 0.3 to 1.5 mm. In the imprint mold 10 (see FIG. 3D) manufactured from the imprint mold substrate 1 in the first embodiment, the opening end 31 of the hollow portion 30 of the support portion 3 is closed by the thin plate portion 2. In the imprint process, particularly when the imprint mold 10 is peeled off, at least the region where the fine concavo-convex pattern is formed in the thin plate portion 2 can be curved. There exists an effect of making peeling of the said imprint mold 10 easy. Therefore, if the thickness T2 of the thin plate portion 2 is too thin or too thick, it may be difficult to bend as intended when the imprint mold 10 is peeled off. Moreover, when thickness T2 of the thin plate part 2 is too thin, there exists a possibility that the intensity | strength of the said imprint mold 10 may fall.

  The support portion 3 has a hollow rectangular tube shape whose outer shape is substantially rectangular in plan view, and a substantially circular hollow portion 30 is formed at a substantially center in plan view. The method for forming the hollow portion 30 is not particularly limited, and for example, the hollow portion 30 may be mechanically processed using a cutting tool or the like, or a resist pattern having an opening corresponding to the hollow portion 30 is formed. Etching may be performed.

  The material which comprises the support part 3 is not specifically limited, The same material as the material which comprises the thin plate part 2 may be sufficient, and a different material may be sufficient as it. When the support part 3 is comprised with a material different from the material which comprises the thin-plate part 2, as a material which comprises the said support part 3, silicon system material; metal material; quartz glass, soda glass, fluorite, Examples include glass materials such as calcium fluoride, magnesium fluoride, acrylic glass, and borosilicate glass; resin materials such as polycarbonate, polypropylene, polyethylene, and other polyolefins, and ceramic materials such as low expansion ceramics.

  The size of the outer shape of the support portion 3 in plan view may be substantially the same as the size of the thin plate portion 2 or may be larger than the thin plate portion 2. When the sizes are substantially the same, since there is no step when viewed from the thin plate portion 2 side in the imprint mold substrate 1 to be manufactured, for example, the thin plate portion 2 and the support portion 3 are joined. If chamfering or the like of the end face portion is necessary after that, it can be easily performed. On the other hand, when the support part 3 is larger than the thin plate part 2, the position shift at the time of joining of the thin plate part 2 and the support part 3 is also permitted in the process mentioned later.

  Further, the size of the hollow portion 30 (opening end 31 closed by the thin plate portion 2) in plan view is a size that can include at least a region where a fine uneven pattern is formed on the main surface 2A of the thin plate portion 2. It is. In the plan view, the hollow portion 30 has a size capable of including a fine uneven pattern, so that the imprint process using the imprint mold produced from the imprint mold substrate 1 in the present embodiment, particularly imprint. At the time of peeling of the mold, the effect that at least the region where the fine unevenness pattern is formed is curved to facilitate peeling from the imprint resin can be exhibited.

  The thickness T3 of the support portion 3 can be appropriately set according to the design value of the depth of the concave portion 4 of the imprint mold 10 manufactured from the imprint mold substrate 1 in the first embodiment. It can be set to about 10 mm.

  As a method of activating the surfaces of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3, for example, the second surface of the thin plate portion 2 is exposed by exposing the thin plate portion 2 and the support portion 3 to a plasma atmosphere. 2B and a method of activating the surface of the support surface 3A of the support portion 3; an ion gun (for example, product name: LX-, manufactured by ULVAC, Inc.) on each of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3; The surface of the second surface 2B of the thin plate portion 2 and the surface of the support surface 3A of the support portion 3 are activated by irradiating an ion beam of Ar or the like using an ion beam irradiation apparatus having 1400, CGIB-001A, etc. Methods and the like. If damage to the surface such as the second surface 2B of the thin plate portion 2 caused by ion beam irradiation becomes a problem, for example, a gas cluster ion beam (GCIB) with relatively little damage to the surface is applied to the thin plate portion 2. Two or more surfaces, such as irradiating the second surface 2B and the support surface 3A of the support portion 3 to activate the surface and removing surface contamination that is difficult to remove by GCIB by chemical cleaning before GCIB irradiation, etc. Processing may be combined. Similarly, if Ar is used, for example, a neutralized atomic beam may be irradiated instead of the ion beam.

Examples of the plasma atmosphere include a plasma atmosphere containing a gas such as He, H ₂ , O ₂ , and N ₂ .
By exposing the thin plate portion 2 and the support portion 3 to a plasma atmosphere, the surfaces of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 are terminated with a functional group (OH group or the like) having high reaction activity. be able to. Thereby, the 2nd surface 2B of the thin plate part 2 and the support surface 3A of the support part 3 can be directly joined in the process mentioned later.

  Further, when each of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 is irradiated with an ion beam, a state in which dangling bonds, which are dangling bonds of surface atoms, are exposed on those surfaces is formed. . By bringing the second surface of the thin plate portion 2 in such a state and the support surface 3A of the support portion 3 into contact with each other, a very strong bonding state between the two (thin plate portion 2 and the support portion 3) can be realized.

[Jointing process]
Next, as shown in FIG. 2B, after positioning the thin plate portion 2 and the support portion 3, the opening end 31 of the support portion 3 is closed by the second surface 2 </ b> B of the thin plate portion 2. The second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 are brought into contact with each other.

  As the surface activation treatment, when the thin plate portion 2 and the support portion 3 are exposed to a plasma atmosphere, the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 are heated in contact with each other. As a result, the reaction of the functional group (OH group or the like) on the surface of the second surface 2B of the thin plate portion 2 and the functional group (OH group or the like) on the surface of the support surface 3A of the support portion 3 causes The two surfaces 2B and the support surface 3A of the support portion 3 can be directly joined via oxygen (-O-).

  The heating temperature in the heat treatment is preferably 200 to 300 ° C. If the heating temperature exceeds 300 ° C., the thin plate portion 2 may be distorted. On the other hand, when the heating temperature is less than 200 ° C., the functional group (OH group or the like) on the surface of the second surface 2B of the thin plate portion 2 and the functional group (OH group or the like) on the surface of the support surface 3A of the support portion 3 It is difficult for the reaction between the two to proceed, and sufficient bonding strength may not be obtained.

  The heat treatment is preferably performed under a reduced pressure atmosphere of 0.1 atm or less and an atmosphere in which an air flow of an inert gas such as dry nitrogen can be controlled. By performing the heat treatment in such an atmosphere, excess gas generated at the bonding interface between the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 is quickly discharged, and the It is difficult to allow excess gas to enter the bonding interface, and it is possible to suppress a decrease in bonding strength due to gas trapping at the bonding interface.

  On the other hand, as the surface activation treatment, when each of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 is irradiated with an ion beam, the surface is dangling that is a dangling bond of surface atoms. Since the ring bond is exposed, it can be directly or minutely (X-ray Photoelectron Spectroscopy (XPS), Glow Discharge Mass Spectrometry, Dangling bonds are bonded to each other through impurities (for example, Fe, Cr, Ni, Ti, Mo, Mn, P, Al, Cu, etc.) in which the constituent element ratio obtained by GDMS is about several ppb to several ppm. . Thereby, since the thin plate part 2 and the support part 3 are joined at an atomic level, a very strong joined state can be realized.

[Etching process]
Subsequently, an etching process is performed on a portion of the second surface 2 </ b> B of the thin plate portion 2 exposed from the hollow portion 30 of the support portion 3. By the surface activation treatment, the surface of the second surface 2B of the thin plate portion 2 is activated, and the surface is terminated with a highly reactive functional group (OH group or the like) or dangling bonds are exposed. Or formed. And the surface of the area | region (part exposed from the hollow part 30 of the support part 3 after joining with the support part 3) of the 2nd surface 2B of the thin plate part 2 which is not concerned with joining with the support part 3 is Fe on the surface. In some cases, impurities such as Cr, Ni, Ti, Mo, Mn, P, Al, and Cu, and oxides such as SiO ₂ and Al ₂ O ₃ may adhere. In particular, when a dangling bond is exposed on the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 by irradiation with an ion beam, the dangling bond and impurities are bonded to each other. End up. As a result, the optical properties (particularly, the transmittance of light having a wavelength of 400 nm or less) of the thin plate portion 2 (the portion exposed from the hollow portion 30 of the support portion 3) are deteriorated. In particular, when a quartz glass substrate, a sapphire substrate, a calcium fluoride substrate, or the like is used as the thin plate portion 2, the impurities and oxides are likely to adhere, and the optical characteristics are remarkably deteriorated. On the other hand, there is almost no difference in the transmittance of light having a wavelength exceeding 400 nm as the whole imprint mold substrate 1.

  In the imprint mold substrate 1 manufactured in the present embodiment, the thin plate portion 2 is formed of a transparent substrate, and the imprint mold 10 (see FIG. 3D) manufactured from the imprint mold substrate 1 is Since it is used for the optical imprint process, the optical characteristics of the thin plate part 2 (the part exposed from the hollow part 30 of the support part 3) are deteriorated as a result of the surface activation process. There is a possibility that sufficient optical characteristics cannot be obtained. That is, the imprint resist may be hard to be cured by light (UV or the like) transmitted through the thin plate portion 2.

  Therefore, in the present embodiment, after the thin plate portion 2 and the support portion 3 are joined, the portion of the second surface 2B of the thin plate portion 2 that is exposed from the hollow portion 30 of the support portion 3 is subjected to an etching process. Thereby, impurities etc. adhering to the part exposed from the hollow part 30 of the support part 3 among the 2nd surface 2B of the thin plate part 2 can be removed, and the optical characteristic (especially wavelength 400nm or less) of the thin plate part 2 is removable. Light transmittance) can be improved.

As such an etching process, a method according to the type of deposits on the second surface 2B of the thin plate portion 2 can be employed. For example, the thin plate of the imprint mold substrate 1 in an acidic etching solution, an alkaline etching solution, or the like. Examples include a wet etching process in which the second surface 2B of the part 2 is brought into contact; a dry etching process in which the imprint mold substrate 1 is exposed to a plasma atmosphere containing a CF-based gas such as CF ₄ or CHF ₃ .

  In the surface activation step, when the second surface 2B of the thin plate portion 2 is irradiated with an ion beam, the transmittance of the thin plate portion 2 is changed according to the irradiation direction of the ion beam to the second surface 2B of the thin plate portion 2. Distribution occurs. Specifically, the transmittance of the second surface 2B of the thin plate portion 2 is lower in the region closer to the ion beam irradiation source than in the region far from the ion beam irradiation source. This distribution of transmittance follows the transmittance of the thin plate portion 2 (the portion exposed from the hollow portion 30 of the support portion 3) after the etching process. Therefore, in order to make the transmittance of the thin plate portion 2 (the portion exposed from the hollow portion 30 of the support portion 3) substantially uniform, in the surface activation step, the transmittance distribution is the second surface of the thin plate portion. What is necessary is just to change the irradiation direction of an ion beam so that it may become substantially uniform within 2B.

  On the other hand, the substrate for imprint mold (and the imprint mold produced therefrom) generally has notches and patterns indicating the orientation. Since the imprint mold substrate 1 manufactured in the present embodiment can generate a distribution in the transmittance of the thin plate portion 2 according to the irradiation direction of the ion beam, the transmittance distribution is optically inspected. Thus, the orientation of the imprint mold substrate can be grasped.

  Through the etching process described above, the imprint mold substrate 1 is manufactured. Since the imprint mold substrate 1 manufactured in this manner is formed by joining the thin plate portion 2 and the support portion 3 having the hollow portion 30, the second surface 2 </ b> B of the thin plate portion 2 and the hollow portion of the support portion 3. 30, a recess having a desired accuracy is formed.

  In addition, since the second surface of the thin plate portion 2 (the portion exposed from the hollow portion 30 of the support portion 3) is etched by the etching process, the transmittance of the bonding interface between the thin plate portion 2 and the support portion 3 (particularly, The transmittance of light having a wavelength of 400 nm or less is about 2 to 10% lower than the transmittance of the second surface of the thin plate portion 2 (the portion exposed from the hollow portion 30 of the support portion 3).

  According to the method for manufacturing the imprint mold substrate 1 according to the present embodiment, the second surface 2B of the thin plate portion 2 and the hollow portion 30 are joined by joining the thin plate portion 2 and the support portion 3 having the hollow portion 30. Therefore, the imprint mold substrate 1 having the desired accuracy of the recess can be manufactured. In addition, since the surface activation process is performed on each of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3, both of them (the thin plate portion 2 and the support portion 3) are directly joined. Therefore, excessive heating and pressurization are not required, and it is possible to prevent the thin plate portion 2 from being distorted, the optical characteristics are lowered, and the like.

<Method for producing imprint mold>
By using the imprint mold substrate 1 manufactured according to the present embodiment, for example, an imprint mold can be manufactured as follows. FIG. 3 is a process flow diagram showing the respective steps of the imprint mold manufacturing method according to the present embodiment in cross-sectional views.

  In the imprint mold manufacturing method according to the present embodiment, first, an imprint mold substrate 1 in which a hard mask layer 5 such as a metal chromium film is provided on the first surface 2A of the thin plate portion 2 is prepared. A resist pattern 61 corresponding to the fine concavo-convex pattern 11 of the mold 10 is formed on the pattern formation region PA of the first surface 2A (see FIG. 3A).

  The imprint mold substrate 1 in the present embodiment includes a high transmittance portion 1A and a low transmittance portion 1B that have different transmittances for light having a wavelength of 400 nm or less. Therefore, by measuring the transmittance of light (light having a wavelength of 400 nm or less) of the substrate 1 for imprint mold, a region corresponding to the concave portion 4 even from the first surface 2A side of the thin plate portion 2, that is, fine unevenness The pattern formation area PA where the pattern 11 is to be formed can be reliably grasped. Therefore, the resist pattern 61 can be formed at an accurate position on the pattern formation area PA.

  The thickness of the hard mask layer 5 is appropriately determined in consideration of the etching selection ratio according to the material constituting the thin plate portion 2 of the imprint mold substrate 1, the aspect ratio of the fine uneven pattern 11 in the imprint mold 10, and the like. Can be set.

  The resist material constituting the resist pattern 61 is not particularly limited, and a conventionally known energy beam sensitive resist material (for example, electron beam sensitive resist material, ultraviolet ray sensitive resist material, etc.) or the like may be used. it can.

  The method for forming the resist pattern 61 is not particularly limited. For example, the resist pattern 61 can be formed by an electron beam lithography method, a photolithography method, or the like.

  Subsequently, the hard mask layer 5 is etched by a dry etching method using the resist pattern 61 as a mask to form a hard mask pattern 51 (see FIG. 3B). Then, using the hard mask pattern 51 as a mask, the first surface 2A of the thin plate portion 2 of the imprint mold substrate 1 is etched to form a fine uneven pattern 11 (see FIG. 3C).

  Finally, the hard mask pattern 51 is removed (see FIG. 3D). Thereby, the fine concavo-convex pattern 11 is formed on the first surface 2 </ b> A of the thin plate portion 2, and the imprint mold 10 having the highly accurate concave portion 4 can be manufactured.

  In the case where an electron beam lithography method or a photolithography method is used when forming the resist pattern 61, the thin plate portion 2 is more uniform and flat when viewed from the exposure light source side. preferable. Therefore, it is preferable that the thin plate portion 2 has a thickness corresponding to the size or is joined to the support portion 3 so as to have a tension.

  The imprint mold substrate 1 used in the imprint mold manufacturing method according to the present embodiment joins the thin plate portion 2 and the support portion 3 having the hollow portion 30, so that the second surface 2 </ b> B of the thin plate portion 2 is hollow. Since the concave portion is formed by the portion 30, the concave portion has a desired accuracy. Therefore, according to the imprint mold manufacturing method of the present embodiment, it is possible to easily manufacture the imprint mold 10 having the concave portions 4 with desired accuracy.

  In the above method, the resist pattern 61 is formed by an electron beam lithography method, a photolithography method, or the like. However, the nanoimprint lithography method using an imprint mold having a fine uneven pattern corresponding to the resist pattern 61 A resist pattern 61 may be formed.

<Imprint mold>
The imprint mold 10 manufactured as described above has a first surface 2A and a second surface 2B opposite to the first surface 2A, and a thin plate on which the fine uneven pattern 11 is formed on the first surface 2A side. Portion 2 and a hollow cylindrical support portion 3 that supports the second surface 2B of the thin plate portion 2, and the thin plate portion 2 and the support portion 3 so as to close the opening end 31 of the hollow cylindrical support portion 3. Are joined to each other so that the hollow portion 30 of the support portion 3 and the second surface 2B of the thin plate portion 2 that closes the opening end 31 are provided.

  As described above, the imprint mold 10 according to the present embodiment is an imprint produced by subjecting the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 to surface activation treatment and bonding them together. Manufactured from the mold substrate 1. By this surface activation treatment, impurities or the like adhere to the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3, and the transmittance of light (light having a wavelength of 400 nm or less) of the thin plate portion 2 and the support portion 3 is increased. Although it is reduced, since the etching process is performed after the thin plate portion 2 and the support portion 3 are joined, impurities and the like attached to the portion exposed through the support portion 3 in the second surface 2B of the thin plate portion 2 are removed. Thus, the transmittance of light (light having a wavelength of 400 nm or less) in the portion is improved. On the other hand, the transmittance of light having a wavelength of more than 400 nm hardly fluctuates regardless of the presence or absence of such impurities. Therefore, in the imprint mold 10 according to the present embodiment, the portion corresponding to the concave portion 4 (the portion exposed by the hollow portion 30) of the thin plate portion 2 is configured as the high transmittance portion 1A, and the high transmittance portion 1A The outer part (the support part 3 and the part joined to the support part 3 in the thin plate part 2) is configured as the low transmittance part 1B. In the present embodiment, a fine uneven pattern 11 is formed on the high transmittance portion 1A of the first surface 2A of the thin plate portion 2, and an identification mark (for identifying individual imprint molds) is formed on the low transmittance portion 1B. An auxiliary mark such as an uneven pattern) or an alignment mark is formed.

  Generally, on the surface of the imprint mold (the surface corresponding to the first surface 2A of the thin plate portion 2 in the case of the imprint mold in the present embodiment), a relatively thick portion (the thin plate portion 2 and the support) An identification mark is formed on a portion corresponding to the upper part of the bonding interface with the portion 3. The identification mark is recognized by making light (for example, light having a short wavelength (about 400 nm or less)) incident on the surface of the identification mark and detecting reflected light from the surface of the identification mark. During the mold manufacturing process, conveyance process, and imprint process, the back surface of the imprint mold (the surface corresponding to the opposite surface of the support surface 3A of the support portion 3) may be damaged. When the scratch exists on the same axis in the thickness direction of the imprint mold in relation to the existing identification mark, when light is incident in the thickness direction in order to recognize the identification mark, on the back side of the imprint mold Reflected reflected light is disturbed by the effect of the scratch, and as a result, it becomes difficult to detect reflected light from the surface of the identification mark, and the identification mark is recognized. In such a case, in order to reliably recognize the identification mark, the detection device is mechanically adjusted by, for example, making light incident obliquely on the identification mark from the surface of the identification mark. However, in the imprint mold 10 according to this embodiment, the identification mark is formed on the low transmittance portion 1B of the first surface 2A of the thin plate portion 2 in the present embodiment. Since the reflected light from the surface facing the support surface 3A of the support unit 3 is attenuated (attenuated by about 4 to 20%), the detection accuracy of the reflected light from the surface of the identification mark is not required without mechanical adjustment of the detection device. It is possible to reliably detect the identification mark simply by adjusting.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  In the above embodiment, the surface activation treatment is performed on each of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3, but the present invention is not limited to such an embodiment. If both are simply joined, the surface activation treatment may be performed on only one of them. In this case, by applying a surface activation process only to the support surface 3A of the support portion 3, if the thin plate portion 2 and the support portion 3 are joined, impurities or the like may adhere to the second surface 2B of the thin plate portion 2. In addition, it is possible to prevent the optical characteristics of the thin plate portion 2 (particularly, the transmittance of light having a wavelength of 400 nm or less) from being deteriorated. As a result, the etching process can be omitted. Note that, as in the above-described embodiment, the surface activation treatment is performed on each of the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3, and then the two are bonded together to form a very strong bonded state. Is desirable because it can be realized.

  In the said embodiment, although demonstrated taking the case of the board | substrate 1 for imprint mold formed by joining the flat thin plate part 2 and the hollow cylindrical support part as an example, this invention is limited to such an aspect. It is not something. For example, you may have the convex structure part 21 in the approximate center of the 1st surface 2A of the thin plate part 2 (refer FIG. 4 (A)), and Cr, Cr may be provided in the 1st surface 2A of the thin plate part 2. The hard mask layer 5 may be formed of a chromium-based material such as nitride of silicon; a silicon-based material such as silicon, an alloy containing silicon, silicon oxide, or silicon nitride (FIG. 4B). reference). In the imprint mold substrate 1 shown in FIG. 4A, the upper surface 21 </ b> A of the convex structure portion 21 constitutes a pattern area PA where the fine uneven pattern 11 is formed.

  In the above embodiment, the imprint mold substrate 1 is prepared by bonding the thin plate portion 2 and the support portion 3, and the fine uneven pattern 11 is formed on the first surface 2 </ b> A of the thin plate portion 2. However, the present invention is not limited to such an embodiment. For example, the imprint mold 10 may be manufactured by preparing the thin plate portion 2 in which the fine unevenness pattern 11 is formed on the first surface 2A and joining the thin plate portion 2 and the support portion 3.

  EXAMPLES Hereinafter, although an Example etc. are given and this invention is demonstrated in detail, this invention is not limited to the following Example etc. at all.

[Example 1]
A quartz glass substrate (152 mm × 152 mm, thickness T2 = 1.00 mm) as the thin plate portion 2 and a support portion 3 (152 mm × 152 mm, thickness T3 = 5.35 mm, diameter of the hollow portion 30 made of quartz glass = 60 mm). The second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 were each irradiated with an Ar ion beam using an ion beam irradiation apparatus having an ion gun (manufactured by ULVAC, LX1400). As the thin plate portion 2, a thin plate portion having a 25 mm × 35 mm rectangular convex structure portion 21 height (30 μm) at the center in plan view was used.

  Next, the thin plate portion 2 and the support portion 3 were joined by bringing the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3 into contact with each other. Finally, the imprint mold substrate 1 is obtained by performing an etching process (immersion process in sulfuric acid / hydrogen peroxide) on the second surface 2B of the thin plate part 2 (the part exposed from the hollow part 30 of the support part 3). It was made.

[Example 2]
An imprint mold substrate 1 was produced in the same manner as in Example 1 except that the etching process was not performed after the thin plate portion 2 and the support portion 3 were joined.

Example 3
An imprint mold substrate 1 was produced in the same manner as in Example 1 except that the support portion 3 was made of silicon.

Example 4
After the thin plate portion 2 and the support portion 3 were joined, an imprint mold substrate 1 was produced in the same manner as in Example 3 except that a heat treatment at 900 ° C. was performed before the etching treatment.

[Test Example 1]
The thin plate portion 2 of the imprint mold substrate 1 of Examples 1 and 2 (the portion exposed from the hollow portion 30 of the support portion 3; Samples 1 and 2) and the thin plate portion 2 prepared in Example 1 (Sample 3) The transmittance (transmittance of light having a wavelength of 250 to 650 nm) was measured using a transmittance measuring device (product name: MCPD-7700, manufactured by Otsuka Electronics Co., Ltd.). The results are shown in FIG.

  FIG. 5 is a graph showing the relationship between the transmittance (%) of samples 1 to 3 and the wavelength of light. As is clear from the graph shown in FIG. 5, the imprint mold substrate 1 (sample 2) that was not subjected to the etching process after joining the thin plate portion 2 and the support portion 3 has a light transmittance of a wavelength of 400 nm or less. It was about 2-8% lower. On the other hand, the imprint mold substrate 1 (sample 1) subjected to the etching treatment after the joining of the thin plate portion 2 and the support portion 3 showed the same transmittance as the thin plate portion 2 (sample 3).

  From this result, the surface activation process is performed on the second surface 2B of the thin plate portion 2 and the support surface 3A of the support portion 3, and after both are joined, the second surface 2B of the thin plate portion 2 (the hollow portion 30 of the support portion 3). It was confirmed that the transmittance of light having a short wavelength (wavelength of about 400 nm or less) can be improved by performing an etching process on a portion exposed from the above.

[Test Example 2]
For the imprint mold substrate 1 of Example 3 and Example 4, the amount of strain of the thin plate portion 2 was measured using a flatness measuring device (product name: FLATMASTER) manufactured by Corning. As a result, no distortion occurred in the imprint mold substrate 1 of Example 3, but in the imprint mold substrate 1 of Example 4, the hollow portion 30 of the support portion 3 in the thin plate portion 2. It was confirmed that deflection (distortion) of 30 μm or more occurred in the exposed portion.

  Distortion due to excessive heating when the thin plate portion 2 and the support portion 3 are joined particularly occurs when the thin plate portion 2 and the support portion 3 are made of different materials. When the thin plate portion 2 and the support portion 3 are made of different materials, there is a difference in thermal expansion coefficient between the thin plate portion 2 and the support portion 3, so that the thin plate portion 2 is distorted by heating at the time of joining. it is conceivable that. From the results of the test example 2 described above, among the examples 3 and 4 in which the thin plate portion 2 and the support portion 3 are made of different materials, the distortion occurred in the example 4 because the thin plate portion 2 and the support portion 3 were supported. It is inferred that this is caused by excessive heating during the joining with the part 3.

  The present invention is useful in the field of microfabrication technology in which a nanoimprint process is performed using an imprint mold in order to form a fine uneven pattern on a semiconductor substrate or the like.

DESCRIPTION OF SYMBOLS 1 ... Imprint mold substrate 1A ... High transmittance part 1B ... Low transmittance part 2 ... Thin plate part 2A ... 1st surface 2B ... 2nd surface 3 ... Support part 3A ... Support surface 31 ... Opening end 4 ... Concave 10 ... Imprint mold 11 ... fine uneven pattern

Claims (10)

A thin plate portion having a first surface on which a fine concavo-convex pattern can be formed and a second surface facing the first surface, and a hollow cylindrical support portion having a support surface for supporting the second surface of the thin plate portion. And a method for manufacturing an imprint mold substrate in which the opening end of the hollow cylindrical support portion is closed by the second surface of the thin plate portion and the thin plate portion and the support portion are joined. There,
A surface activation step of activating the second surface of the thin plate portion and / or the surface of the support surface of the support portion;
And a joining step of joining the second surface of the thin plate portion and the support surface of the support portion so as to close one end of the opening of the support portion with the second surface of the thin plate portion. A method for producing a printed mold substrate.   2. The method of manufacturing an imprint mold substrate according to claim 1, further comprising an etching step of etching a portion exposed through the support portion of the second surface of the thin plate portion.   The method for producing an imprint mold substrate according to claim 2, wherein the thin plate portion is a quartz glass substrate, a sapphire substrate, or a calcium fluoride substrate.   In the surface activation step, the second surface of the thin plate portion and / or the support surface of the support portion is exposed to a plasma atmosphere to activate the surfaces thereof. The manufacturing method of the board | substrate for imprint molds in any one.   In the joining step, the second surface of the thin plate portion and the support surface of the support portion are heated at 200 to 300 ° C. in a state where the second surface of the thin plate portion and the support surface of the support portion are in contact with each other. The method for manufacturing an imprint mold substrate according to claim 4, wherein:   In the surface activation step, the surface of the thin plate portion is activated by irradiating the second surface of the thin plate portion and / or the support surface of the support portion with an ion beam. The manufacturing method of the board | substrate for imprint molds in any one.   It includes the process of forming a fine unevenness | corrugation pattern in the 1st surface side of the said thin-plate part of the said substrate for imprint molds manufactured by the manufacturing method of the substrate for imprint molds in any one of Claims 1-6. A method for manufacturing an imprint mold. A thin plate portion having a first surface and a second surface opposite to the first surface, the fine uneven pattern being formed on the first surface side, and a support surface for supporting the second surface of the thin plate portion. A hollow cylindrical support portion, and the thin plate portion and the support portion are joined so that one end of the opening of the hollow cylindrical support portion is closed by the second surface of the thin plate portion. A method for producing a print mold comprising:
A surface activation step of activating the second surface of the thin plate portion and / or the surface of the support surface of the support portion;
And a joining step of joining the second surface of the thin plate portion and the support surface of the support portion so as to close one end of the opening of the support portion with the second surface of the thin plate portion. A method for producing a print mold. A thin plate portion having a first surface on which a fine concavo-convex pattern can be formed and a second surface facing the first surface, and a hollow cylindrical support portion having a support surface for supporting the second surface of the thin plate portion. An imprint mold substrate in which the thin plate portion and the support portion are joined so that one end of the opening of the hollow cylindrical support portion is closed by the second surface of the thin plate portion,
The imprint mold substrate includes a high transmittance portion having a high transmittance of light having a wavelength of 400 nm or less in the thickness direction of the thin plate portion, and a low transmittance portion having a light transmittance lower than that of the high transmittance portion. Including
The high transmittance part is constituted by a part of the thin plate part exposed by a hollow cylindrical part of the support part,
The low transmittance portion is constituted by a portion including a bonding interface between the thin plate portion and the support portion,
The imprint mold substrate according to claim 1, wherein the transmittance of light having a wavelength of more than 400 nm in the thickness direction of the thin plate portion is substantially constant as the entire imprint mold substrate. A thin plate portion having a first surface and a second surface opposite to the first surface, the fine uneven pattern being formed on the first surface side, and a support surface for supporting the second surface of the thin plate portion. A hollow cylindrical support portion, and the thin plate portion and the support portion are joined so that one end of the opening of the hollow cylindrical support portion is closed by the second surface of the thin plate portion. A print mold,
The imprint mold includes a high transmittance portion having a high transmittance of light having a wavelength of 400 nm or less in the thickness direction of the thin plate portion, and a low transmittance portion having a light transmittance lower than that of the high transmittance portion. ,
The high transmittance part is constituted by a part of the thin plate part exposed by a hollow cylindrical part of the support part,
The low transmittance portion is constituted by a portion including a bonding interface between the thin plate portion and the support portion,
An auxiliary mark is formed in a portion corresponding to the low transmittance portion of the first surface of the thin plate portion,
The imprint mold characterized in that, as a whole of the imprint mold, the transmittance of light having a wavelength of more than 400 nm in the thickness direction of the thin plate portion is substantially constant.

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