JP6089451B2 - Nanoimprint mold and manufacturing method thereof - Google Patents

Description

  The present invention relates to a nanoimprint mold used in a nanoimprint method for forming a fine uneven pattern and a method for producing the same.

  In recent years, especially in semiconductor devices, high speed operation and low power consumption operation have been required due to further progress in miniaturization. Further, a high technology such as integration of functions called a system LSI has been demanded.

  Under such circumstances, the lithography technology, which is the key to producing semiconductor device patterns, has pointed out the limitations of the photolithography method due to the problem of exposure wavelength as device pattern miniaturization progresses.・ The nanoimprint method is attracting attention as a fine patterning method.

  In the nanoimprint method, a nanoimprint mold (template) with a nanometer-size uneven pattern formed in advance on the surface is pressed against a transfer material such as resin applied to the surface of the substrate to be processed, and the transfer material is mechanically deformed to generate unevenness. This is a technology for transferring patterns precisely. Then, for example, by using a patterned transfer material as a resist mask, the substrate to be processed can be finely processed.

  In such a nanoimprint method, once a nanoimprint mold is prepared, the same nanostructure can be easily and repeatedly molded. Therefore, high throughput is obtained and it is economical, and nanoprocessing technology with less harmful waste Therefore, in recent years, applications are not limited to semiconductor devices but in various fields.

  A nanoimprint mold used in the nanoimprint method is required to have pattern dimension stability, chemical resistance, processing characteristics, and the like. In the nanoimprint method, the concave-convex pattern shape of the nanoimprint mold must be faithfully transferred to a transfer material such as a resin. In the case of the optical nanoimprint method, generally, UV light for photocuring is transmitted. A quartz glass substrate is used as a mold substrate.

  The nanoimprint mold manufacturing method is performed by etching a substrate such as quartz glass to form an uneven pattern on the surface of the substrate (see, for example, Patent Document 1). FIG. 6 is a cross-sectional view for explaining a process example of a conventional nanoimprint mold manufacturing method over time.

  First, as shown in FIG. 6A, a metal thin film 132 such as chrome (Cr) is formed on a substrate 131 such as quartz glass to be a nanoimprint mold as a hard mask material at the time of substrate etching. An electron beam sensitive resin (electron beam resist) is applied to the substrate, and exposure, development, and the like are performed using an electron beam (EB) lithography technique to form a resist pattern 133.

  Next, as shown in FIG. 6B, the resist pattern 133 is subjected to slimming treatment with oxygen plasma, thereby reducing the thickness and width of the resist pattern. The slimming process in this step is not an indispensable step. For example, it may be determined whether or not to perform the slimming process according to the target resist pattern line width.

  Next, as shown in FIG. 6C, the metal thin film 132 is etched using the slimmed resist pattern 133a as a mask to form the metal thin film pattern 132a. Next, the substrate 131 is etched using the metal thin film pattern 132a as a mask, so that the substrate 131 is formed with a recess 136 as shown in FIG. Next, as shown in FIG. 6E, the resist pattern 133a is peeled and removed. The resist pattern 133a may be removed before the substrate 131 is etched.

  Next, as shown in FIG. 6F, a method is used in which the metal thin film pattern 132a is removed by etching, and the nanoimprint mold 130 in which the uneven pattern 137 is provided on the substrate 131 is produced.

JP 2005-345737 A

  However, the nanoimprint mold is manufactured using a so-called bulk process for processing the substrate itself. Therefore, in particular, as the uneven pattern becomes finer, so-called microloading becomes more prominent in the etching process, and it tends to become difficult to maintain the processing depth and the uniformity of the processing shape.

  Further, in the bulk process for processing the substrate itself, a process for manufacturing a mask with a fine pattern and processing the substrate itself using the mask is required. It tends to be difficult to achieve reduction.

  The present invention was devised under such circumstances, and its purpose is to provide excellent dimensional accuracy of the concavo-convex part of the nanoimprint mold having a fine concavo-convex pattern, and to reduce the mold manufacturing cost. An object of the present invention is to provide a nanoimprint mold and a method for manufacturing the same.

In order to solve the problems have been described above, the production method of a nanoimprint mold of the present invention, on the first main surface of the substrate, comprising a straight Seppa turn, and the pattern, the bonding interface between the base plate the method of manufacturing a nanoimprint mold but present, a step of preparing a substrate having a first major surface comprising a flat, on the first main surface of said substrate to form a straight Settotsu shaped resist bodies in a predetermined pattern A resist pattern forming step, a first film portion forming step of depositing a first film portion so as to cover a side surface and an upper surface of the convex resist body, and a first main surface portion of the substrate; Etch back the film part to expose the upper surface of the convex resist body and the first main surface part of the substrate, and leave the first film part on the side surface of the convex resist body to form the side wall convex part. Etch to form And a side wall convex part pattern forming step for forming a side wall convex part pattern by removing the convex resist body, and the step of digging the substrate is not included. The

Moreover, as a preferable aspect of the method for producing a nanoimprint mold of the present invention, a second side so as to cover the side surface and the upper surface of the side wall convex portion formed by the side wall convex portion pattern forming step and the first main surface portion of the substrate. A second film part forming step for depositing the film part is further provided.

  As a preferred embodiment of the method for producing a nanoimprint mold of the present invention, the first film part is formed by an ALD method (atomic layer deposition method).

  As a preferred embodiment of the method for producing a nanoimprint mold of the present invention, the second film portion is formed by an ALD method (atomic layer deposition method).

  Further, as a preferred embodiment of the method for producing a nanoimprint mold of the present invention, a method of forming a convex resist body in the resist pattern forming step is configured as an electron beam (EB) lithography method, a photolithographic method, or a nanoimprint method.

The nanoimprint mold of the present invention is a nanoimprint mold for transferring a concavo-convex transfer pattern to the transfer layer by being pressed against the transfer layer, and the nanoimprint mold includes a substrate having a first main surface portion formed of a plane, on the first major surface portion, have a contributing convex body formation directly before SL uneven transfer pattern, all convex bodies contribute to the formation of the uneven transfer pattern is composed of a first film portion is, the first film portion is made consists ALD film (atomic layer deposition film), and the convex body configured to bonding interface is present between the board.

In a preferable embodiment of the nanoimprint mold of the present invention, the convex body is constructed as a separate member from said base plate, constructed as being present in a state of being directly erected on the substrate Is done.

Further, as a preferred embodiment of the nanoimprint mold of the present invention, the second film portion is covered so as to cover the side surface and the upper surface of the convex body constituted by the first film portion and the first main surface portion of the substrate. The second film portion is formed of an ALD film (atomic layer deposition film).

  As a preferred embodiment of the nanoimprint mold of the present invention, all the convex bodies that contribute to the formation of the concave-convex transfer pattern are composed of a first film portion and a second film portion.

  The method for producing a nanoimprint mold of the present invention includes a step of preparing a substrate having a first main surface portion formed of a plane, and a convex resist body on the first main surface portion of the substrate directly or via an intermediate film. A resist pattern forming step for forming a predetermined pattern, and a first film portion that covers a side surface and an upper surface of the convex resist body and a first main surface portion or an upper surface of the intermediate film of the substrate. A film portion forming step; and etching back the first film portion to expose the upper surface of the convex resist body and the first main surface portion of the substrate or the upper surface of the intermediate film, and the first film portion Etch-back process for forming side wall convex portions to be left on the side surfaces of the convex resist bodies, and side wall convex pattern forming processes for forming side wall convex patterns by removing the convex resist bodies. When being configured to have, because there is no step of recessing the substrate, excellent in dimensional accuracy of the uneven portion of the nanoimprint mold, moreover it is possible to reduce mold manufacturing cost.

1 (A) to 1 (F) are cross-sectional views for explaining a process example of the method for producing a nanoimprint mold of the present invention over time. FIG. 2 is a cross-sectional view for explaining a process example of the manufacturing method of the nanoimprint mold of the present invention, and is a cross-sectional view when a second film portion forming step is further provided after the step of FIG. is there. FIG. 3 is a plan view for explaining a process example of the method for producing a nanoimprint mold of the present invention, and corresponds to a plan view at the time of the process shown in FIG. FIG. 4 is a plan view showing a state after removing both ends in the longitudinal direction of the closed loop pattern in the plan view shown in FIG. FIG. 5 is a perspective view drawn so that the state of the closed loop pattern can be easily understood, and corresponds to a part of the perspective view at the time of the step shown in FIG. FIG. 6 is a cross-sectional view for explaining a process example of a conventional nanoimprint mold manufacturing method over time.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the form demonstrated below, In the range which does not deviate from a technical thought, it can implement in various deformation | transformation. In the accompanying drawings, the vertical and horizontal scales may be exaggerated for the sake of explanation, and the actual scales may differ.

  First, the manufacturing method of the nanoimprint mold of the present invention will be described with reference to FIGS. 1 to 5 so that the configuration of the nanoimprint mold of the present invention can be understood more easily.

<Nanoimprint mold manufacturing method>
1 (A) to 1 (F) are cross-sectional views for explaining a process example of the method for manufacturing a nanoimprint mold of the present invention over time, and FIG. 2 further illustrates a process after the process shown in FIG. 1 (F). FIG. 3 is a cross-sectional view when a second film portion forming step is provided, FIG. 3 is a plan view at the time of the step shown in FIG. 1F, and FIG. 4 is shown in FIG. 3 as an example of an additional step. FIG. 5 is a plan view showing a state after removing both ends in the longitudinal direction of the closed loop pattern in the plan view, and FIG. 5 is a schematic perspective view drawn so that the state of the closed loop pattern can be easily understood. It is a perspective view at the time of the process shown by (F).

  The method for producing a nanoimprint mold of the present invention includes (1) a step of preparing a substrate having a first main surface portion consisting of a plane, and (2) on the first main surface portion of the substrate, directly or via an intermediate film. A resist pattern forming step for forming a convex resist body in a predetermined pattern; and (3) a first film portion so as to cover a side surface and an upper surface of the convex resist body and a first main surface portion of the substrate or an upper surface of the intermediate film. And (4) etching back the first film portion to expose the upper surface of the convex resist body and the first main surface portion of the substrate or the upper surface of the intermediate film. Etch-back process for forming sidewall convex portions leaving the film portion 1 on the side surfaces of the convex resist body, and (5) Side wall convex pattern formation for forming the pattern of the sidewall convex portions by removing the convex resist body Process, Configured to have. As an embodiment of the present invention, a case where a slimming process that can be provided as a preferred embodiment is provided after the resist pattern forming process of (2) above is illustrated.

  Hereinafter, each step will be sequentially described.

(1) Step of Preparing a Substrate Having a First Main Surface Part That is a Plane As shown in FIG. 1A, a substrate 10 that serves as a base of a nanoimprint mold is prepared. A first main surface portion 11a is formed on the main surface 11 on one side of the substrate 10, and the first main surface portion 11a is a plane on which a convex resist body described later can be formed. In FIG. 1 (A), an example is shown in which the entire area of the principal surface 11 on one side of the substrate 10 constitutes a first principal surface portion 11a composed of a flat surface, but is not limited to this configuration. For example, the substrate 10 can be a so-called mesa structure in which only the area where the convex resist body is provided constitutes the first main surface portion of the flat surface partially protruding.

  The material of the substrate 10 can be appropriately selected. For example, when the nanoimprint mold is used as a so-called mold for optical imprinting, the substrate 10 is formed using a transparent base material that can transmit irradiation light. Further, glass such as quartz glass, silicate glass, calcium fluoride, magnesium fluoride, and acrylic glass, resin such as polycarbonate, polypropylene, and polyethylene, or any laminated material thereof can be used. For example, when the nanoimprint mold is used as a so-called thermal imprint mold, the substrate 10 does not necessarily need to be a transparent base material, for example, a metal such as nickel, titanium, or aluminum, or a semiconductor such as silicon or gallium nitride. May be used.

  The thickness of the substrate 10 serving as the base of the nanoimprint mold can be set in consideration of the strength of the substrate, the handleability, and the like, and can be set as appropriate within a range of about 300 μm to 10 mm, for example. Further, as described above, the substrate 10 may have a so-called mesa structure in which the first main surface portion 11a on which the convex resist body is formed is a flat surface. The number of stages of the mesa structure is not limited to one but may be a plurality of stages.

(2) Resist Pattern Forming Step Next, as shown in FIG. 1B, a convex resist body 30 is formed in a predetermined pattern on the first main surface portion 11a of the substrate 10 via the intermediate film 20. A resist pattern forming step is performed. Although the intermediate film 20 is interposed in the illustrated example, the convex resist body 30 is formed in a predetermined pattern directly on the first main surface portion 11 of the substrate 10 without the intermediate film 20 being interposed. You may do it.

  The pattern formation of the convex resist body 30 can be formed by an electron beam (EB) lithography method, a photolithographic method, or a nanoimprint method.

  When the electron beam (EB) lithography method is used as a first technique, a resist forming step of forming an electron beam sensitive resin film on the intermediate film 20 of the substrate 10 is performed, and then the formed electron beam sensitive Electron beam drawing is performed on the conductive resin film so as to form a desired pattern.

  After the electron beam drawing is completed, a resist developing process for developing the electron beam sensitive resin film is performed. For example, when a positive electron beam sensitive resin film is used, it remains as a resist in a state where an unirradiated portion is not decomposed, and a convex resist body 30 is formed in a predetermined pattern (a negative electron beam sensitive resin). When a film is used, the irradiated portion remains as a resist without being decomposed, and a pattern opposite to the positive type is formed).

  As a second method, when the photolithography method is used, a resist forming step for forming a photosensitive resin film is performed on the intermediate film 20 of the substrate 10, and then the desired photosensitive resin film is applied to the desired photosensitive resin film. The exposure operation is performed through the mask pattern so as to form the pattern. After the exposure operation is completed, a resist development process for developing the photosensitive resin film is performed. For example, when a positive photosensitive resin film is used, the unexposed portion remains as a resist without being decomposed, and the convex resist body 30 is formed in a predetermined pattern (using a negative photosensitive resin film). In this case, the exposed portion remains as a resist without being decomposed, and a pattern opposite to the positive type is formed).

  As a third method, when the nanoimprint method is used, for example, a photocurable resin material is supplied and disposed as an object to be transferred on the intermediate film 20 of the substrate 10 by a dispenser, an inkjet, or the like. Next, a mold having a desired concavo-convex structure is brought into contact with the disposed resin material, and pressure is applied as necessary (so-called mold pressing step). In this state, the resin material becomes a resin layer having an uneven structure, and the resin material is cured by irradiating the resin layer with ultraviolet rays (so-called resin curing step). Next, by separating the mold from the resin material, a concavo-convex structure in which the concavo-convex structure of the mold is inverted is formed on the intermediate film 20 of the substrate 10 in a predetermined pattern. Thereafter, the so-called residual film is removed by oxygen ashing or the like, whereby the pattern of the convex resist body 30 is formed. The convex resist body 30 referred to in the present invention refers to a structure including a resin material as a main component.

  The intermediate film 20 provided as necessary on the substrate 10 is, for example, a film having a function of improving adhesion between the substrate 10 and a first film unit 40 described later, or a conductive film, or It is preferably composed of a film having both functions. The intermediate film 20 may be configured as a laminated film having two or more layers. For example, the conductive intermediate film 20 can be operated so as to guide electrons during pattern drawing in electron beam (EB) lithography. However, even in electron beam (EB) lithography, it is possible to draw a pattern with a conductive film formed on the surface of the electron beam sensitive resin film, and the presence of the conductive intermediate film 20 is essential. is not. Further, when the adhesion between the substrate 10 and the first film unit 40 is good, the intermediate film 20 may not be provided.

  In the case where the intermediate film 20 is provided, specific materials include Si-based, Ta-based, and Cr-based films. The film thickness is usually 50 nm or less, particularly about several nm to 50 nm.

  When the nanoimprint mold is used as a so-called mold for optical imprinting, it is desirable that the intermediate layer 20 be a transparent material that can transmit irradiation light.

(2 ′) Slimming Step In this embodiment, as shown in FIG. 1C, a slimming step that can be provided as necessary is added after the resist pattern forming step.

  In the slimming process, the convex resist body 30 is processed by, for example, oxygen plasma and slimmed to form a convex resist body 30a that is slimmed as shown in FIG.

  In this specification, the slimming is to reduce the width of the pattern of the convex resist body 30 and reduce the film thickness by wet etching or dry etching (including oxygen plasma treatment). For example, by performing slimming by oxygen plasma treatment, a pattern width of about ½ can be formed without changing the pattern pitch of the convex resist body 30 formed first.

(3) First Film Portion Forming Step Next, as shown in FIG. 1D, the side surface 32 and the upper surface 31 of the convex resist body 30a and the upper surface of the intermediate film 20 (in the case where the intermediate film 20 is not provided) Then, a first film part forming step is performed in which the first film part 40 is deposited so as to cover the first main surface part 11a) of the substrate 10.

  The first film part 40 is not particularly limited as long as a series of films are formed along the surface to be deposited. Preferably, the first film part 40 is an ALD method (atomic layer deposition method). A formed atomic layer deposition film is desirable. The surface to be deposited may be a surface of any shape such as an uneven surface or a curved surface. By using the ALD method, a film can be formed accurately at a low temperature. Furthermore, step coverage is also very good.

  The 1st film | membrane part 40 may be comprised from 1 layer, and may be comprised as a laminated film of two or more layers. The film thickness of the first film part 40 is preferably, for example, a half-pitch designed film thickness. For example, a series of atomic layers is continuous until a thickness of about several nm to several hundred nm is obtained. Stacked on.

  Examples of the specific material constituting the first film part 40 include Si-based, Al-based, and Ti-based films. In addition, when the nanoimprint mold is used as a so-called mold for optical imprinting, it is desirable that the first film portion 40 be a transparent material that can transmit irradiation light.

When the first film portion 40 is formed, the glass transition temperature of the resist constituting the convex resist body 30 (30a) so as not to damage the previously formed convex resist body 30 (30a). It is desirable to operate at a first temperature T _L , well below Tg (eg, 20-100 ° C., more preferably room temperature).

(4) Etchback Step Next, as shown in FIG. 1E, the first film portion 40 is etched back, and the upper surface 31 of the convex resist body 30a and the upper surface of the intermediate film 20 (the intermediate film 20 is removed). If not provided, an etch-back process is performed in which the first main surface portion 11a of the substrate 10 is exposed and the first film portion 40 is left on the side surface 32 of the convex resist body 30a to form the side wall convex portion 45. Etch back is an operation in which the entire surface is etched in the thickness direction by etching.

Etch back may be performed using an appropriate etching gas according to the material constituting the first film portion 40. For example, when the first film part 40 is made of silicon oxide (SiO ₂ ), it is only necessary to etch back using a fluorine-based gas such as CF ₄ , CHF ₃ , C ₂ F ₆ as an etching gas. .

(5) Side Wall Convex Pattern Formation Step Next, as shown in FIG. 1 (F), the pattern of the side wall convex part 45 constituted by the remaining first film part 40 by removing the convex resist body 30a. The side wall convex part pattern formation process which forms is implemented.

  In the present invention, the first film portion 40 is etched back and the upper surface 31 of the convex resist body 30a is exposed in the etch back process, which is the previous process. 30a can be easily removed.

  The convex resist body 30a can be selectively removed by dry processing using an oxygen-based gas. For example, dry processing such as dry etching using oxygen plasma or ozone processing can be cited as a suitable example. The convex resist body 30a is a portion that becomes a so-called core when forming the pattern of the side wall convex portion 45, and a similar convex object made of an inorganic compound is used as the core instead of the convex resist body 30a of the present application. In this case, not only the number of steps for forming the inorganic compound increases, but also the dry etching selectivity for removing the inorganic compound core is worse than that of the convex resist body 30a core, which causes variation in pattern dimensions. . In addition, when wet etching is used to remove the inorganic compound core, the pattern of the side wall protrusion 45 may be collapsed or deformed due to the surface tension of the wet etching solution. In the present invention, by using the convex resist body 30a core and the dry treatment, it is possible to minimize collapse and deformation of the pattern of the side wall convex portion 45.

  In addition, when the removal of the resist core (the convex resist body 30 (30a)) is completed, in order to improve the adhesion strength, the film strength, and the like of the first film portion 40, for example, a high temperature of about 200 to 800 ° C. It is desirable to heat-treat with (annealing).

  In the present invention, the side wall convex portion 45 as shown in FIG. 1 (F) is completed because the side wall convex portion 45 is formed on the side surface of the rod-shaped convex resist body 30a as a core. At this point, when the pattern of the side wall convex portion 45 is viewed from the plane, a state is formed in which a plurality of side wall convex portions 45 forming a closed loop as shown in FIG. 3 are arranged at a predetermined pitch. The side wall convex part 45 which forms one closed loop is formed from a pair of side wall convex parts 45 and 45 arranged so as to sandwich the convex resist body 30a. Referring to FIG. 1F, the first and second side wall protrusions 45 from the left form side wall protrusions 45 that form one closed loop, and the first and second side wall protrusions 45 from the right. By the side wall convex portion 45, a side wall convex portion 45 that forms one closed loop is formed.

  When it is desired to form the pattern of the side wall convex portion 45 in the line and space form as shown in FIG. 4 during the nanoimprint mold manufacturing, the length of the side wall convex portion 45 forming the closed loop shown in FIG. It is necessary to remove both ends 46 in the direction.

  In order to remove both end portions 46 in the longitudinal direction, for example, the side wall protrusions in an exposed state in a state where the resist film is covered as a mask in an area surrounded by abcd in FIG. A method of etching and removing the vicinity of both end portions 46 of the portion 45 may be mentioned.

  When manufacturing the nanoimprint mold, both end portions 46 in the longitudinal direction of the side wall convex portion 45 that forms the closed loop shown in FIG. 3 may be left. In this case, after transferring the concavo-convex transfer pattern of the transfer layer onto the substrate to be processed by an actual nanoimprint operation, defects in the transfer layer caused by the presence of the transferred portion corresponding to the edge are added as necessary. What is necessary is just to process. As the structure of the nanoimprint mold, when both end portions 46 in the longitudinal direction of the side wall convex portion 45 forming a closed loop are left, the strength against collapse or deformation of the side wall convex portion 45 is further increased because of the closed loop. The effect is manifested.

  The removal of both end portions 46 in the longitudinal direction of the side wall convex portion 45 forming the closed loop may be performed at any stage as long as the first film portion forming process is completed.

(6) Second Film Portion Forming Step Preferably Provided After the above-described side wall protrusion pattern forming step, as shown in FIG. 2, the side surface 45b of the side wall protrusion 45 formed by the side wall protrusion pattern forming step and Second film portion forming step of depositing the second film portion 50 so as to cover the upper surface 45a and the upper surface of the intermediate film 20 (the first main surface portion 11a of the substrate 10 when the intermediate film 20 is not provided). It is preferable to carry out further.

  By providing this step, the composite convex body 55 including the second film portion 50 attached to the side wall convex portion 45 is more firmly formed by the presence of the second film portion 50 and collapses. And the strength against deformation is further increased.

  The second film part 50 is not particularly limited as long as a series of films are formed along the surface to be deposited, but preferably by the ALD method (atomic layer deposition method). A formed atomic layer deposition film is desirable. By using the ALD method, a thin film having an extremely high film density can be formed with high accuracy. Furthermore, step coverage is also very good.

  The second film unit 50 may be composed of one layer or may be composed of a laminated film of two or more layers. The second film part 50 has a particularly reinforcing action, and its film thickness is, for example, about several nm to several tens of nm.

  Examples of specific materials constituting the second film unit 50 include Si-based, Al-based, and Ti-based films. When the nanoimprint mold is used as a so-called mold for optical imprinting, it is desirable that the second film unit 50 be a transparent material that can transmit irradiation light.

  The second film portion 50 can be formed at a low temperature (for example, about room temperature to 100 ° C.) or at a high temperature (for example, about 100 to 600 ° C.) in order to improve adhesion strength, film strength, and the like. ). When the film is formed at a low temperature, it is desirable to perform a heat treatment (annealing) at a high temperature of about 200 to 800 ° C., for example, in order to improve adhesion strength, film strength, and the like.

  As described above, the first film portion 40 is also preferably heat-treated (annealed) at a high temperature of, for example, about 200 to 800 ° C. after film formation in order to improve adhesion strength and film strength. Since the first film portion 40 is formed on the convex resist body 30, it is preferable to perform film formation at a low temperature, and the heat treatment (annealing) is performed on the convex resist body 30 (30a). It is preferable to carry out after the removal (for example, after the resist core removal step).

  Specific modes such as heat treatment when the first film portion 40 and the second film portion 50 are formed in combination are as follows. That is, (a) the first film portion 40 is formed at a low temperature, and then the first film portion 40 is heat-treated, and the second film portion 50 is formed at a high temperature later. (B) The first film portion 40 is formed at a low temperature, and then the first film portion 40 is heat-treated, and then the second film portion 50 is formed at a low temperature. Thereafter, the heat treatment at a high temperature is performed. Do. (C) The first film part 40 is formed at a low temperature, and the subsequent second film part 50 is formed at a high temperature. (D) The first film part 40 is formed at a low temperature, and the subsequent second film part 50 is formed at a low temperature, and then heat treatment is performed at a high temperature. As shown in the above (a) and (b), the first film part 40 is heat-treated at an early stage to improve the adhesion strength and film strength of the first film part 40 itself. In each operation process in each process, there is a merit that the pattern of the side wall convex portion 45 formed on the basis of the first film portion 40 is not easily collapsed or deformed. On the other hand, as shown in the above (c) and (d), the heat treatment of the second film portion 50 and the first film portion 40 is performed during or after the subsequent formation of the second film portion 50. It is possible to simplify the heat treatment process by performing the process together.

  Through the above steps, a nanoimprint mold as shown in FIG. 1 (F) or FIG. 2 is formed.

  The nanoimprint mold of the present invention is used for performing a nanoimprint method. For example, a mold for transferring an uneven transfer pattern to a transfer layer by being pressed against a transfer layer such as a resin provided on a substrate to be processed. It is. A transfer layer such as a resin may be initially provided on the nanoimprint mold side instead of the substrate to be processed.

  As shown in FIG. 1F, for example, the nanoimprint mold as the first embodiment includes an intermediate film 20 on a substrate 10 having a first main surface portion 11a formed of a plane and the first main surface portion 11a. And a convex body (side wall convex portion 45) that contributes to the formation of the concave-convex transfer pattern. The intermediate film 20 is provided as necessary. Without providing the intermediate film 20, a convex body (side wall protrusion) that directly contributes to the formation of the concave-convex transfer pattern on the first main surface portion 11 a of the substrate 10. Part 45).

  The convex body (side wall convex portion 45) in the present invention is not integrally formed so as to dig the main surface of the substrate 10, but as a member different from the substrate 10 and the intermediate film 20, It exists directly or on a state where it is erected via the intermediate film 20. Accordingly, there is a bonding interface at a position where the bottom of the convex body (side wall convex portion 45) and the substrate 10 or the intermediate film 20 are bonded. The other members in the present invention are not judged based on the coincidence / non-coincidence of materials, but are judged based on whether or not there is a bonded interface, and only those that are integrally formed are excluded. This is the purpose. The mold of the present invention in which the bonding interface exists is a convex body (from the bonding interface when the uneven pattern of the nanoimprint mold deteriorates and is not practically used, or when the specification of the uneven pattern is changed and the pattern is recreated. By removing the side wall protrusions 45), the substrate 10 can be reused.

  Furthermore, in the nanoimprint mold of the present invention, all the convex bodies that contribute to the formation of the concave-convex transfer pattern are composed of one or more film portions. That is, the convex body is configured as a side wall convex portion 45 that is a part of the first film portion 40 as shown in FIG. The first film unit 40 is preferably configured as an ALD film (atomic layer deposition film). The ALD film (atomic layer deposition film) may be an atomic layer composed of one layer, but it is usually desirable to be configured as two or more atomic layers. By forming all the convex bodies (side wall convex portions 45) that contribute to the formation of the concave / convex transfer pattern from one layer or two or more film portions (atomic layer deposition film), there is an effect that pattern deformation is difficult to occur. To express.

  The shape, material, thickness, etc. of the substrate 10 constituting the nanoimprint mold of the present invention, the characteristics, material, film thickness, etc. of the intermediate film 20 that can be provided as necessary, a part of the first film portion 40 Since the laminated structure, material, and the like of the side wall convex portion 45 are described when the above-described nanoimprint mold manufacturing method is described, refer to the description there. Further, as described above, as the structure of the nanoimprint mold, both end portions 46 in the longitudinal direction of the side wall convex portion 45 that forms a closed loop can be left (see FIG. 3).

  For example, as shown in FIG. 2, the nanoimprint mold as the second embodiment includes a convex body including a side wall convex portion 45 that is a part of the first film portion 40, and side surfaces and an upper surface of the convex body. , As well as an integrated product with the second film part 50 deposited so as to cover the upper surface of the intermediate film.

  Thereby, as shown in FIG. 2, the new composite convex body 55 composed of the convex body (side wall convex portion 45) and the second film portion 50 contributes directly to the formation of the concave-convex transfer pattern. However, the convex body (side wall convex portion 45) configured as the core material is also configured to contribute to the formation of the concave-convex transfer pattern. This is because the desired convex shape of the composite convex body 55 cannot be formed without the convex body (side wall convex portion 45).

  Since the laminated structure, material, film thickness, and the like of the second film unit 50 are described when the above-described method for manufacturing a nanoimprint mold is described, refer to the description in that place. In addition, when the both ends 46 of the longitudinal direction of the side wall convex part 45 which forms a closed loop are left as a structure of a nanoimprint mold (refer FIG. 3), the 2nd film | membrane part is maintained, maintaining the structure of the closed loop. 50 is deposited on the side wall protrusion 45.

<Other Embodiments of Nanoimprint Mold>
As another embodiment, only the intermediate film 20 located at the base of the convex body (side wall convex portion 45) shown in FIG. 1 (F) is left, and the convex body (side wall convex portion 45) is not erected. All of the intermediate film 20 is removed, and the intermediate film 20 is made of a material such as Cr, which easily causes a contrast difference depending on the presence or absence of the intermediate film. By adopting such a configuration, it is possible to perform a verification inspection or the like of the position where the convex body (side wall convex portion 45) is erected by irradiating the nanoimprint mold with inspection light. .

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

A synthetic quartz glass substrate having an outer shape of 6 inches square and a thickness of 0.25 inches was prepared as the light transmissive substrate 10. On one main surface of the prepared substrate 10, SiO ₂ was deposited by sputtering to form a 10 nm thick SiO ₂ film 20 (intermediate film 20).

Next, an electron beam sensitive resin (electron beam resist) is applied onto the SiO ₂ film 20, and a resist pattern (convex pattern) having a resist thickness of 40 nm in the form of a line and space pattern with a pattern width of 30 nm and a pitch of 60 nm is formed by electron beam drawing. Pattern of the resist-like body 30).

  Next, the formed resist pattern was subjected to slimming by oxygen plasma treatment, and the pattern width of the resist after slimming was set to 20 nm. The resist thickness was 35 nm.

Side and top of the slimming resist pattern, and the SiO ₂ film is formed by ALD to cover the upper surface of the SiO ₂ film was formed an SiO ₂ coating film having a thickness of 10 nm (first film portion). The film forming temperature was room temperature.

Then, the entire surface of the SiO ₂ coating film (first film portion) is etched back by dry etching using CF ₄ gas, to expose the resist pattern and the SiO ₂ film (intermediate film), of SiO ₂ to be Sidewall protrusions were formed leaving the covering film on the side surfaces of the resist pattern.

Next, the resist pattern was selectively removed by dry etching using oxygen plasma (resist core removal operation), and a substrate having SiO ₂ side wall protrusions formed on the SiO ₂ film (intermediate film) was produced.

The side wall (side wall convex part) of SiO ₂ was a line and space pattern form having a pattern width of 10 nm, a thickness (height) of 35 nm, and a pitch of 30 nm.

   In the present invention, since the core material is an organic resist, it is easy to remove the resist (resist core removal operation), and the side wall protrusion does not fall or deform. Furthermore, the dimensional accuracy of the side wall protrusions was extremely excellent.

Next, a SiO ₂ film is formed by an ALD method so as to cover the side and upper surfaces of the sidewall convex pattern and the upper surface of the SiO ₂ film (intermediate film), and a 5 nm thick SiO ₂ coating film (second film) is formed. Part) and a new composite convex body 55 composed of the side wall convex part 45 and the second film part 50 was formed. The composite convex body 55 produced a nanoimprint mold having a line-and-space pattern form with a pattern width of 20 nm, a thickness (substantial height that functions as a convex portion) of 35 nm, and a pitch of 30 nm.

  The dimensional accuracy of the composite convex body 55 was extremely excellent. That is, the variation in the height of the convex portion was an error within ± 1% with respect to the standard design dimension. Similarly, the variation in the width of the convex portion was an error within ± 2% with respect to the standard design dimension.

  In the above manufacturing method, the heat treatment at a high temperature of the two ALD films (the first film part and the second film part) was performed as follows.

  That is, (a) the first film part was formed at room temperature, and after the resist core removal operation, the first film part was heat-treated at 400 ° C., and the second film part was formed at 400 ° C. later.

  In addition, another heat treatment method, that is, (b) the first film part is formed at room temperature, and after the resist core removing operation, the first film part is heat treated at 400 ° C. The film part is formed at room temperature, and then the second film part is heat-treated at 400 ° C., (c) the first film part is formed at room temperature, and after the resist core removal operation, the second (D) The first film part is formed at room temperature, and after the resist core removal operation, the second film part is formed at room temperature, and then 400 ° C. The effect similar to the effect mentioned above was able to be confirmed by any of the methods of heat-treating with.

Further, in the above-described embodiments, even when the ALD film is changed from the SiO ₂ film to the SiN film, the same effects as those described above can be confirmed.

  The present invention can be used in technical fields that require various fine processing, and can be applied to, for example, the manufacture of electronic components including a semiconductor integrated circuit and high-density recording media.

DESCRIPTION OF SYMBOLS 10 ... Board | substrate 11 ... Main surface 11a ... 1st main surface part 20 ... Intermediate film 30, 30a ... Convex-shaped resist body 40 ... 1st film | membrane part 45 ... Side wall convex part 50 ... 2nd film | membrane part 55 ... Composite convex-shaped object

Claims (9)

On the first major surface of the substrate, comprising a straight Seppa turn, and the pattern, in the manufacturing method of a nanoimprint mold bonding interface is present between the board,
Preparing a substrate having a first main surface portion comprising a plane;
On the first main surface of the substrate, and the resist pattern forming step of forming a straight Settotsu shaped resist bodies in a predetermined pattern,
A first film portion forming step of depositing a first film portion so as to cover a side surface and an upper surface of the convex resist body and a first main surface portion of the substrate;
The first film portion is etched back to expose the upper surface of the convex resist body and the first main surface portion of the substrate, and leave the first film portion on the side surface of the convex resist body. Etch back process for forming side wall protrusions;
And a side wall convex pattern forming step of forming a side wall convex pattern by removing the convex resist body, and the step of digging the substrate is not included. Method. A second film portion forming step of depositing a second film portion so as to cover the side surface and upper surface of the side wall convex portion formed by the side wall convex portion pattern forming step and the first main surface portion of the substrate; The manufacturing method of the nanoimprint mold of Claim 1 provided.   The method for manufacturing a nanoimprint mold according to claim 1, wherein the first film part is formed by an ALD method (atomic layer deposition method).   The method for producing a nanoimprint mold according to claim 2 or 3, wherein the second film part is formed by an ALD method (atomic layer deposition method).   The method for producing a nanoimprint mold according to any one of claims 1 to 4, wherein the method of forming a convex resist body in the resist pattern forming step is an electron beam (EB) lithography method, a photolithographic method, or a nanoimprint method. . A nanoimprint mold for transferring an uneven transfer pattern to the transfer layer by being pressed against the transfer layer,
The nanoimprint mold is
A substrate having a first main surface portion formed of a plane;
On the first major surface portion, have a contributing convex body formation directly before SL uneven transfer pattern,
All the convex bodies that contribute to the formation of the concavo-convex transfer pattern are composed of a first film part, and the first film part is composed of an ALD film (atomic layer deposition film). and body, nanoimprint mold, wherein a bonding interface is present between the board. The convex body is constructed as a separate member from said base plate, nanoimprint mold according to claim 6 which is present in a state of being directly erected on the substrate. A second film portion is deposited so as to cover a side surface and an upper surface of the convex body composed of the first film portion, and a first main surface portion of the substrate, and the second film portion is The nanoimprint mold according to claim 6 or 7, comprising an ALD film (atomic layer deposition film).   9. The nanoimprint mold according to claim 8, wherein all of the convex bodies that contribute to the formation of the concave-convex transfer pattern include a first film portion and a second film portion.

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