JP6136271B2 - Manufacturing method of imprint mold - Google Patents

Description

  The present invention relates to a method for manufacturing an imprint mold having a concavo-convex structure obtained by inverting a concavo-convex structure formed on an original master mold at least once.

  With the progress of miniaturization and high integration of semiconductor integrated circuits, various photolithography techniques have been developed as pattern forming techniques in order to realize fine processing for manufacturing the semiconductor integrated circuits.

  In recent years, attention has been focused on an imprint method as a pattern formation technique that replaces various photolithography techniques. This imprint method is a pattern forming technology that uses a mold member (mold) with a fine concavo-convex structure formed on the surface of a substrate and transfers the concavo-convex structure to a transfer material to transfer the fine concavo-convex structure at the same magnification. It is. The imprint method is expected to be applied to the manufacture of semiconductor elements, magnetic recording media, and the like.

  As a mold having a fine concavo-convex structure used in the imprint method, a mold produced by electron beam (EB) lithography is conventionally known (see Non-Patent Document 1). The mold produced in this way has high accuracy in the shape and dimensions of the concavo-convex structure, while the production cost becomes high, and after a predetermined number of transfer steps, the material to be transferred (imprint In some cases, the concavo-convex structure formed on the resin or the like may be defective, or the concavo-convex structure of the mold may be damaged.

  When defects in the concavo-convex structure formed in the material to be transferred in this way and damages to the concavo-convex structure of the mold have occurred, each time it is replaced with a new mold produced by electron beam (EB) lithography, This leads to an increase in the cost of products such as semiconductor elements manufactured through the imprint method.

  Therefore, when performing an imprint method on an industrial scale, generally, a concavo-convex structure in which a mold produced by electron beam (EB) lithography is used as a master mold and the concavo-convex structure of the master mold is inverted using the master mold. A large number of first copy molds having a concavo-convex structure equivalent to a replica of a master mold, wherein the concavo-convex structure of the first copy mold is further inverted using the first copy mold, Those copy molds are used as molds in the imprint method (see Patent Document 1).

  The copy mold thus obtained can be mass-produced at a low cost. Therefore, by using them as a mold in the imprint method, even if the mold is damaged or a concavo-convex structure formed on the material to be transferred is caused by the mold, new one after another The imprint method can be performed while exchanging the mold, and the manufacturing cost of a product such as a semiconductor element manufactured through the imprint method can be reduced. In addition, by preparing a large number of copy molds, the copy molds can be set in each of a plurality of imprint apparatuses and used simultaneously, and the productivity of products such as semiconductor elements can be improved.

JP 2010-282959 A

Author Taniguchi, “Nanoimprint Technology for the First Time”, P180, 2005, published by Industrial Research Committee

A mold used for manufacturing a product such as a semiconductor element or a magnetic recording medium has a concavo-convex structure having an extremely fine dimension of nano order according to a pattern dimension required for the semiconductor element or the like. For example, a magnetic recording medium called a bit patterned medium is required to have a pattern size corresponding to one bit of 20 nm or less in order to realize a recording density of ² Tb / inch ² or more. In order to create a master mold having such an uneven structure corresponding to a pattern with such an extremely fine dimension through electron beam lithography, it is necessary to scan with a minimal spot beam. There is a problem that enormous time is required and productivity is lowered.

  Further, in order to meet the above-described demands for fine pattern dimensions and further demands for further miniaturization, it is necessary to use a high-resolution resist material used in electron beam lithography. However, the higher the resolution of the resist material, the lower the sensitivity to the electron beam, so that enormous time is required to create the pattern latent image, and the productivity may be further reduced.

  As described above, no technology has been proposed to realize the production of a mold having an extremely fine concavo-convex structure with extremely high productivity from the production of a master mold to the production of a copy mold. There is a current situation that the development of such technology is desired.

  The present invention has been developed under the above circumstances, and an object thereof is to provide a method for producing an imprint mold with high productivity.

In order to solve the above-described problems , the present invention provides a concavo-convex structure of the master mold by interposing a material to be transferred between one surface of the master mold on which the concavo-convex structure is formed and one surface of the first substrate. A first transfer layer forming step of forming a first transfer layer having a first inverted concavo-convex structure in which the first transfer layer is inverted, and the first transfer layer is provided with the first transfer layer by separating the first transfer layer and the master mold. Reduced concavo-convex structure forming step of forming a reduced concavo-convex structure obtained by reducing the size of the first inverted concavo-convex structure in the first transfer layer by a first peeling step for obtaining a substrate and a sidewall method and / or a self-organization method A first concavo-convex structure obtained by etching one surface of the first substrate using the reduced concavo-convex structure as an etching mask, and reducing the size of the concavo-convex structure of the master mold on one surface of the first substrate. Form The first substrate is a glass substrate, an area Sm defined by the outer shape of one surface of the master mold, and an area Sp defined by the outer shape of the one surface of the first substrate; The area Sm physically includes the area Sp, and the concave-convex structure of the master mold is formed on one surface of the master mold by photolithography. A method for producing a print mold is provided (Invention 1 ).

In the above invention (Invention 1 ), the first substrate is configured as a mesa-structured substrate having a convex portion on the one surface of the first substrate. In the first transfer layer forming step, the uneven structure and the It is preferable to form the first transfer layer having the first inverted concavo-convex structure on the convex portion with the material to be transferred interposed between the convex portion (Invention 2 ).

In the above inventions (Inventions 1 and 2 ), the first substrate may be configured such that the thickness of the region portion where the first inverted concavo-convex structure is formed is thinner than the thickness of other region portions (Invention 3 ). In the above inventions (Inventions 1 to 3 ), the first substrate may have a rectangular outer shape (Invention 4 ).

In the above inventions (Inventions 1 to 4 ), a first concavo-convex structure forming step of forming the first concavo-convex structure on the first substrate by etching the first substrate using the first transfer layer or the reduced concavo-convex structure as a mask. Further inclusion is preferred (Invention 5 ).

In the above invention (invention 5 ), a material to be transferred is interposed between one surface of the first substrate on which the first concavo-convex structure is formed and one surface of the second substrate. A second transfer layer forming step of forming a second transfer layer having a second inverted concavo-convex structure obtained by inverting the first concavo-convex structure, separating the second transfer layer and the first substrate, and performing the second transfer It is preferable to further include a second peeling step for obtaining the second substrate having a layer (Invention 6 ).

In the said invention (invention 1-6 ), a 200 mm wafer or a larger wafer can be used as a base material which comprises the said master mold (invention 7 ), and a quartz substrate is used as said 1st board | substrate. (Invention 8 )

In the said invention (invention 1-8 ), in the said 1st transcription | transfer layer formation process, the said to-be-transferred material is dripped by the inkjet system on one surface of the said master mold, or one surface of the said 1st board | substrate, It is preferable that the material to be transferred is interposed between one surface of the master mold and one surface of the first substrate (Invention 9 ).

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of an imprint mold with high productivity can be provided.

FIG. 1 is a perspective view of a master mold in the first embodiment of the present invention. 2 is a cross-sectional view taken along line AA of the master mold shown in FIG. FIG. 3 is a process flow diagram showing, in a cross-sectional view, a master mold manufacturing process (using a side wall method) in the first embodiment of the present invention. FIG. 4 is a process flow diagram showing, in a cross-sectional view, a manufacturing process using a self-organization method among the master mold manufacturing processes according to the first embodiment of the present invention. FIG. 5 is a perspective view schematically showing the relationship between the master mold and the first substrate in the first embodiment of the present invention. FIG. 6 is a plane for explaining the relationship between the area Sm defined by the outer shape of one surface of the master mold and the area Sp defined by the outer shape of one surface of the first substrate in the first embodiment of the present invention. FIG. FIG. 7 is a cross-sectional view (FIG. 7A) and a plan view (FIG. 7B) schematically showing the relationship between the master mold and the first substrate in the first embodiment of the present invention. FIG. 8 is a cross-sectional view showing an example of the first transfer layer forming step in the first embodiment of the present invention. FIG. 9 is a cross-sectional view showing a configuration example of the first substrate in the first embodiment of the present invention. FIG. 10 is a process flow diagram showing the process of manufacturing the first mold in the first embodiment of the present invention in a sectional view. FIG. 11 is a process flow diagram showing the process of manufacturing the second mold in the first embodiment of the present invention in a sectional view. FIG. 12 is a cross-sectional view showing an example of a second transfer layer forming step in the first embodiment of the present invention. FIG. 13: is a process flowchart which shows the process (side wall method utilization) which manufactures the 1st mold in the 2nd Embodiment of this invention with sectional drawing. FIG. 14 is a process flow diagram showing, in a cross-sectional view, a manufacturing process using a self-organization method among the manufacturing processes of the first mold in the second embodiment of the present invention. FIG. 15 is a perspective view schematically showing the relationship between the master mold and the first substrate in the third embodiment of the present invention. FIG. 16 is a perspective view showing a master mold in the fourth embodiment of the present invention. FIG. 17 is a cross-sectional view of the master mold shown in FIG. 16 taken along line BB. FIG. 18 is a perspective view (FIG. 18A) showing a specific configuration example of a master mold in the fourth embodiment of the present invention and a cross-sectional view taken along the line C-C (FIG. 18B).

  Before describing the embodiments of the present invention, the background to the present invention will be briefly described while showing the relationship with the prior art so that the features of the present invention can be understood more clearly and easily.

<Background to the Present Invention>
Conventionally, as a master mold substrate, a 6-inch square quartz substrate or a substrate having a diameter (diameter) of 2 to 6 inches has been used. Speaking of producing an imprint mold having an extremely fine pattern, this is due to the common use of an electron beam drawing apparatus. Most of the electron beam drawing apparatuses that are generally used are defined as 6 inches or less (the length of one side for a rectangular substrate, the diameter for a circular substrate) as a substrate size usable as a drawing target substrate. Because.

  In addition, when assuming that a plurality of copy molds used in a general imprint apparatus are manufactured through imprint lithography based on one master mold, so-called step-and-repeat is used as a copy mold substrate. It has been common knowledge that a material larger than the master mold is used in the case of manufacturing by the above-mentioned method, and that a size equivalent to that of the master mold is used in the case of manufacturing by so-called batch transfer.

  The present inventor has come to propose a novel imprint mold manufacturing method capable of adopting a state-of-the-art photolithography technique other than electron beam lithography in manufacturing a master mold without being bound by such conventional common sense. It was.

<First Embodiment>
A first embodiment of the present invention will be described with reference to the drawings.

[Master mold]
First, a master mold used in the imprint mold manufacturing method according to the first embodiment will be described. FIG. 1 is a perspective view of a master mold in the first embodiment, and FIG. 2 is a cross-sectional view taken along line AA of the master mold shown in FIG.

  As shown in FIGS. 1 and 2, the master mold 10 has a concavo-convex structure 14 formed on one surface 10 a on one side of a wafer 12 such as a semiconductor wafer.

  The concavo-convex structure 14 is a structure for transferring the shape to a material to be transferred, which will be described later, for example. In FIG. 1 and FIG. 2, six convex lines are illustrated as the concavo-convex structure 14, but the height of the convex portion (depth of the concave portion), pitch, number, arrangement area (wafer 12) of the concavo-convex structure 14. The area occupied by the formation region of the concavo-convex structure 14 with respect to the one surface 10a), the shape (line shape, dot shape, etc.) and the like are not particularly limited, and can be appropriately set according to the scene to be used. Further, the dimension of the concavo-convex structure 14 (when the concavo-convex structure 14 is a line-and-space shape, the width of the line or space in the short direction) is not particularly limited, but is difficult to form by a photolithography method described later or It is preferable that it is a dimension which cannot be formed, for example, 40 nm or less, Preferably it is 10-30 nm.

  As the wafer 12 such as a semiconductor wafer, a large-diameter wafer which is commonly used by a state-of-the-art photolithography method can be used. For example, a 200 mm (8 inch) wafer or a larger wafer (for example, 300 mm (12 inch) It is preferable to use a wafer). In particular, a 300 mm (12 inch) wafer has high versatility as a fine pattern forming application, and can be suitably used from the viewpoint that applicable apparatuses and facilities are enriched. The 200 mm wafer is a wafer having a diameter standard value of 200 mm, and the 300 mm wafer is a wafer having a diameter standard value of 300 mm. The standard value of the diameter being 200 mm or 300 mm means not having a strict meaning of 200 mm or 300 mm but having an allowable range of ± 1 mm around 200 mm or 300 mm.

  The thickness of the wafer 12 is not particularly limited, but is preferably in the range of 300 μm to 1 mm in consideration of strength and handleability. As a material constituting the wafer 12, a semiconductor such as silicon, gallium arsenide, and gallium nitride, quartz, a laminate of these, and the like can be used. When the concavo-convex structure 14 is formed by dry etching, a silicon wafer capable of performing microfabrication easily and with high accuracy can be suitably used. The wafer 12 may be obtained by bonding a support substrate made of glass or the like to a semiconductor substrate. The wafer is a disc-shaped plate body, and is obtained, for example, by thinly slicing a cylindrical ingot made of a material whose composition is controlled. Further, a notch may be formed on the side surface near the periphery of the wafer.

[Manufacturing method of master mold]
In the master mold 10 based on the wafer 12 as described above, the concavo-convex structure 14 is formed by a combination of a photolithography method and a sidewall method and / or a self-organization method. Specifically, it is formed through the process shown in FIG. FIG. 3 is a cross-sectional view schematically showing a process for forming the concavo-convex structure 14 by a combination of a photolithography method and a sidewall method, which is a manufacturing process of the master mold 10 in the first embodiment. FIG. 4 is a cross-sectional view schematically showing a process for forming the concavo-convex structure 14 by a combination of a photolithography method and a self-assembly method, which is a manufacturing process of the master mold 10 in the first embodiment.

  First, a process of forming the concavo-convex structure 14 by a combination of a photolithography method and a sidewall method will be described. First, a resist pattern Rp is formed by photolithography. As shown in FIG. 3A, a pattern latent image is formed on the resist film formed on one surface 10a of the wafer 12 by a conventionally known exposure method, and developed to form a resist pattern Rp. Note that at least one hard mask layer (not shown) or the like may be provided on one surface 10 a of the wafer 12.

  Although it does not specifically limit as an exposure method, For example, it is preferable to employ | adopt any of immersion exposure, multiple exposure, and extreme ultraviolet exposure.

  Immersion exposure is more accurate by filling the space between the lens of the semiconductor exposure apparatus and the wafer with a medium (liquid) having a higher refractive index than air and using the liquid itself like a lens. This is a technique for performing patterning. In consideration of the handling of the liquid, it is preferable to perform exposure by filling the space between the lens of the semiconductor device and the wafer with water.

  In multiple exposure, in order to obtain a desired pattern, the pattern is divided into N photomasks for the first to Nth exposure photomasks, and a pattern latent image obtained by each photomask is placed on the wafer. This is a technology that combines them into one. N is an integer of 2 or more.

  Extreme ultraviolet exposure is reduction projection lithography that uses EUV (Extreme Ultra Violet) light with a wavelength of 100 nm or less. In extreme ultraviolet exposure, a reflective optical system is used because there is no transparent material in the wavelength range. The wavelength of the EUV light can be appropriately selected depending on the desired pattern size and the material used for the optical system. However, if a Mo-Si multilayer film that is stable and has excellent material handling properties is used as the multilayer film reflector, the wavelength 13 It is preferred to use EUV light in the range of -14 nm.

  The dimension of the resist pattern Rp is not particularly limited, but can be set to about twice the dimension of the concavo-convex structure 14 of the master mold 10. For example, when the size of the concavo-convex structure 14 of the master mold 10 is 20 nm, the size of the resist pattern Rp is about 40 nm.

  The resist pattern Rp serves as a core material C for forming the side wall pattern Wp by a side wall pattern forming step (FIG. 3D) described later, and the side wall pattern Wp is formed on the side wall of the core material C. Therefore, the height (thickness) of the core material C and the side wall pattern Wp after the side wall pattern forming step (FIG. 3D) is substantially the same.

  This sidewall pattern Wp serves as an etching mask for etching the wafer 12 in an etching process (FIG. 3F) described later. Therefore, the height (thickness) of the sidewall pattern Wp depends on the etching selectivity of the material constituting the sidewall pattern Wp and the wafer 12, but the sidewall pattern Wp disappears during the etching process of the wafer 12. The height (thickness) is not required.

  On the other hand, since the core material C is formed by subjecting the resist pattern Rp to the slimming process in the core material forming step (FIG. 3B) described later, the height (thickness) of the core material C is: It becomes lower (thinner) than the height (thickness) of the resist pattern Rp. Therefore, the height (thickness) of the resist pattern Rp is greater than the height (thickness) required for the sidewall pattern Wp in consideration of the slimming amount and the like in the core material forming step (FIG. 3B) described later. Must be high (thick).

In the first embodiment, the resist material constituting the resist pattern Rp may be either a negative type or a positive type, or may be a chemical amplification type thereof.
Subsequently, a fine sidewall pattern Wp is formed by a sidewall method. As shown in FIG. 3B, the resist pattern Rp formed on one surface 10a of the wafer 12 is subjected to a slimming process to form a core material C in which the resist pattern Rp is thinned (core material). Forming step). The slimming process of the resist pattern Rp can be performed by, for example, a wet etching method, a dry etching method, a combination thereof, or the like.

  The slimming amount of the resist pattern Rp is not particularly limited, but when the concavo-convex structure 14 of the master mold 10 has a line and space shape, the space dimension (width in the short direction) of the concavo-convex structure 14 is the resist pattern. Since it depends on the size of the core material C formed by the Rp slimming process, the slimming amount of the resist pattern may be set according to the space size in the concavo-convex structure 14. Usually, the slimming amount is set so that the dimension of the core material C is about half of the resist pattern Rp.

  Subsequently, as shown in FIG. 3C, a side wall material film Wm constituting the side wall pattern Wp is formed on one surface 10a of the wafer 12 including the core material C (side wall material film forming step). As shown in FIG. 3D, the sidewall pattern Wp is formed on the sidewall of the core material C by etching back by anisotropic etching such as RIE (Reactive Ion Etching) (sidewall pattern forming step).

  The sidewall material film Wm can be formed by depositing a sidewall material of a silicon-based material (silicon oxide or the like) by a conventionally known film formation method such as an ALD method (Atomic layer deposition), a CVD method, or a sputtering method. When a resist material is used as the constituent material of the core material C as in the first embodiment, the sidewall material film Wm can be formed by the ALD method which can be formed at a lower temperature and can be controlled at the atomic layer level. It is desirable to form.

  Since the dimension of the concavo-convex structure 14 in the master mold 10 (when the concavo-convex structure 14 is a line and space shape, the width in the short direction of the line or space) depends on the film thickness of the side wall material film Wm, The film thickness of the material film Wm can be set according to the design dimension of the concavo-convex structure 14.

Since the sidewall pattern Wp formed by the etch back is used as an etching mask for the wafer 12, the height T _WP of the sidewall pattern Wp (the length in the direction parallel to the thickness direction of the wafer 12) is It is set as appropriate in consideration of the etching selectivity corresponding to the 12 constituent materials.

  Thereafter, as shown in FIG. 3E, the core material C having the side wall pattern Wp formed on the side walls is removed by ashing (plasma ashing using an oxygen-containing gas or the like) (core material removing step). Thereby, only the core material C is removed, and the side wall pattern Wp can be left on the one surface 10 a of the wafer 12.

  Subsequently, as shown in FIG. 3F, the wafer 12 is selectively etched by a dry etching method using the sidewall pattern Wp as a mask to form a concavo-convex structure 14 (etching step). When the wafer 12 is made of silicon, it is preferable to perform dry etching using a fluorine-based gas.

  In this way, the master mold 10 in which the concavo-convex structure 14 is formed on the one surface 10a of the wafer 12 can be obtained. And since electron beam lithography is not used for preparation of master mold 10, time required for preparation of a master mold can be shortened compared with the former. In addition, as shown in FIG. 3, by combining the photolithography method and the sidewall method, the size of the concavo-convex structure that can be formed by the photolithography method can be reduced, and it is difficult to form by the most advanced photolithography method. Alternatively, even the concavo-convex structure 14 having a size that cannot be formed can be formed.

  In addition, although the aspect which utilizes resist pattern Rp as the core material C was shown as an example in the process mentioned above, this invention is not limited to such an aspect. For example, the core material C made of an inorganic material such as silicon oxide may be formed based on the resist pattern.

  Subsequently, a process of forming the concavo-convex structure 14 by a combination of a photolithography method and a self-organization method will be described.

  First, a resist pattern Rp is formed by photolithography. As shown in FIG. 4A, a pattern latent image is formed on the resist film formed on one surface 10a of the wafer 12 by a conventionally known exposure method, and developed to form a resist pattern Rp. Although it does not specifically limit as an exposure method, For example, it is preferable to employ | adopt one of the liquid immersion exposure mentioned above, multiple exposure, and extreme ultraviolet exposure.

The resulting resist pattern Rp serves as a guide pattern for pattern formation by phase separation of a self-organizing material described later. Therefore, when the concavo-convex structure 14 formed on one surface 10a of the master mold 10 has a substantially equal pitch line and space shape, the distance D _RP between the adjacent resist patterns Rp and Rp is the dimension of the concavo-convex structure 14. The resist pattern Rp is formed so as to be an integer multiple of (the width of the line or space in the short direction), preferably an odd integer multiple.

  Further, the formed resist pattern Rp is removed by etching in a process described later (see FIG. 4C), and the wafer 12 is etched (see FIG. 4D). Therefore, when the concavo-convex structure 14 has a line and space shape with substantially equal pitches, the dimension of the resist pattern Rp (width in the short direction of the line) and the space dimension of the concavo-convex structure 14 (width in the short direction) It becomes almost the same. Therefore, the resist pattern Rp is formed so that the dimension of the resist pattern Rp is substantially the same as the dimension of the concavo-convex structure 14 formed on the one surface 10 a of the master mold 10.

  Note that the resist pattern Rp having substantially the same dimension as that of the concavo-convex structure 14 may be formed by a photolithography method employing the above-described exposure method, or may have a dimension larger than the dimension of the concavo-convex structure 14. After the resist pattern is formed, the resist pattern may be formed by subjecting the resist pattern to a slimming process using a wet etching method, a dry etching method, or a combination thereof.

Subsequently, a fine pattern is formed by a self-organization method.
As shown in FIG. 4B, a self-organizing material containing two different components is applied between the resist patterns Rp and Rp on one surface 10a of the wafer 12, and is baked at a predetermined temperature. Causes phase separation of the structured material. Since the resist pattern Rp serves as a guide pattern during phase separation of the self-assembled material, the self-assembled material is a pattern SA made of one component having a high affinity for the resist pattern Rp that is the guide pattern. ₁ and the pattern SA ₂ composed of the other component, and the patterns SA ₁ and SA ₂ are alternately aligned along the resist pattern Rp.

  As the self-assembling material, a block copolymer composed of two different types of polymers having structures that are difficult to dissolve each other can be used. For example, polystyrene-polymethyl methacrylate (PS-PMMA), polystyrene-polydimethylsiloxane. A block copolymer such as (PS-PDMS) can be used. The two types of polymers constituting the block copolymer are preferably those having different etching resistances (one having high and low etching resistance to a specific etchant).

The dimensions of the patterns SA ₁ and SA ₂ formed by phase separation of the self-assembled material are determined by the molecular weight of the block copolymer as the self-assembled material. Therefore, the molecular weight of the block copolymer used as the self-organizing material can be appropriately set according to the size of the concavo-convex structure 14 of the master mold 10.

Next, as shown in FIG. 4C, the resist pattern Rp and the pattern SA ₂ composed of the other component are removed by etching, and only the pattern SA ₁ composed of one component is formed on the one surface 10 a of the wafer 12. Remain.

Subsequently, as shown in FIG. 4D, the wafer 12 is selectively etched by a dry etching method using the pattern SA ₁ as a mask to form a concavo-convex structure 14 (etching step). When the wafer 12 is made of silicon, it is preferable to perform dry etching using a fluorine-based gas.

  In this way, the master mold 10 in which the concavo-convex structure 14 is formed on the one surface 10a of the wafer 12 can be obtained. And since electron beam lithography is not used for preparation of master mold 10, time required for preparation of a master mold can be shortened compared with the former. Further, as shown in FIG. 4, by combining the photolithography method and the self-organization method, the size of the concavo-convex structure that can be formed by the photolithography method can be reduced, and the state-of-the-art photolithography method can be used. Even a concavo-convex structure 14 having a dimension that is difficult or impossible to form can be formed.

  The master mold 10 obtained as described above has a so-called mesa structure in which the entire formation region of the concavo-convex structure 14 has a convex structure 13 with respect to a region with a non-concave structure (non-formation region of the concavo-convex structure 14). (See FIG. 7A). When the master mold 10 has a mesa structure (convex structure 13), the number of steps in the mesa structure (convex structure 13) is not limited to one step, and may be a plurality of steps. Details of the master mold 10 having the mesa structure (convex structure 13) will be described later.

  Moreover, although the convex-shaped structure is mentioned as an example as the uneven structure 14 of the master mold 10 obtained as mentioned above, it is not limited to such an aspect, The uneven structure 14 is A concave structure may be used.

[Production method of copy mold]
Next, a method for manufacturing an imprint mold (copy mold) using the master mold 10 obtained as described above will be described. FIG. 5 is a perspective view schematically showing the relationship between the master mold 10 and the first substrate 22 in the first embodiment.

(Master mold / first substrate preparation process)
As shown in FIG. 5, the master mold 10 is arranged so that the concavo-convex structure 14 formed on the one surface 10 a of the master mold 10 faces the one surface 22 a of the first substrate 22. In addition, the 1st board | substrate 22 is a board | substrate which comprises the copy mold 20 (refer FIG.10 (E)) by which the 1st uneven structure 24 which reversed the uneven structure 14 of the master mold 10 was formed.

  In the first embodiment, a first concavo-convex structure pattern 19 in which the concavo-convex structure 14 is inverted is formed on one surface 22 a of the first substrate 22 having a smaller dimension than the master mold 10 using the master mold 10. (See FIG. 10C). That is, as shown in FIG. 6, the master mold 10 and the first substrate 22 have an area Sm defined by the outer shape of the one surface 10 a of the master mold 10 and the outer shape of the one surface 22 a of the first substrate 22. When compared with the defined area Sp, the area Sm is in a relationship of physically including the area Sp.

  In the first embodiment, the “relationship that the area Sm physically includes the area Sp” refers to the area Sm defined by the outer shape of the one surface 10a of the master mold 10, as shown in FIG. When the area Sp defined by the outer shape of the one surface 22a of the substrate 22 is overlaid, the area Sp is completely covered (included) by the area Sm, and the area of the area Sm (from the one surface 10a side) This means that the area when viewed is larger than the area Sp of the area Sp (area when viewed from the one surface 22a side).

  As shown in FIG. 7, in the case of a so-called mesa structure in which the entire area of the concavo-convex structure 14 formed in the master mold 10 is a convex structure 13, it is defined by the outer shape of one surface 10a of the master mold 10. The area Sm is not an area defined by the outer shape of the convex structure 13 that is a mesa structure (in the illustrated example, a rectangle having a dimension β), but is the outermost outer shape of the master mold 10 (in the illustrated example, having a dimension α). It means an area defined by (circle). The same applies to the case where the mesa structure has a plurality of stages, which means an area defined by the outermost outer shape (in the example shown, a circle of dimension α). 7A is a cross-sectional view schematically showing the relationship between the master mold 10 and the first substrate 22, and FIG. 7B is a drawing corresponding to FIG. The area Sm defined by the outer shape of the one surface 10a (in the example shown, a circle having a dimension α) and the outer shape of the one surface 22a of the first substrate 22 (in the example shown, a rectangle having a dimension γ). It is a top view explaining that area Sm has the relation which includes area Sp physically in relation to area Sp to be performed.

  The outer shape of the one surface 10a of the master mold 10 and the outer shape of the one surface 22a of the first substrate 22 may be similar to each other, for example, a circular shape (◯ shape) or a circular shape (◯ The shape may be completely different, such as a shape) and a rectangular shape (□ shape). Particularly preferably, the outer shape of one surface 10a of the master mold 10 formed of a wafer is circular (◯ shape), and the outer shape of one surface 22a of the first substrate 22 is rectangular (□ shape). That is, it is preferable that the concavo-convex structure 14 formed on one surface 10 a of the master mold 10 constituted by a wafer is transferred to the one surface 22 a of the rectangular first substrate 22.

  Since the first substrate 22 has a rectangular shape (□ shape), the side wall 22b of the first substrate 22 (see FIG. 10E) is used when the copy mold 20 constituted by the first substrate 22 is used for imprint processing. Can be held under pressure, thereby ensuring the alignment accuracy between the copy mold 20 and another substrate (the substrate onto which the first uneven structure 24 of the copy mold 20 is transferred by the imprint process). . Note that the rectangular shape includes a figure in which the four sides are substantially constituted by straight lines, and the apex has a round shape. An example of the first substrate 22 having a suitable outer shape is a so-called “6025 substrate”. The “6025” substrate is a substrate manufactured in accordance with the standard of 6 inch square and 0.25 inch thickness.

  As described above, in the first embodiment, the concavo-convex structure 14 formed on the large-diameter wafer 12 commonly used in photolithography other than electron beam lithography is a rectangular shape used as a mold in a general imprint apparatus. By transferring to the substrate 22, the size and shape of the substrate to be handled can be converted.

  When the pattern 14 is formed by transferring the concavo-convex structure 14 of the master mold 10 to the first substrate 22, either the optical imprint method or the thermal imprint method can be employed. When the optical imprint method is employed, when a general-purpose semiconductor wafer is used as the wafer 12 constituting the master mold 10, light (ultraviolet rays) cannot be transmitted. It is preferable to use a transparent substrate made of 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.

  On the other hand, when the thermal imprint method is adopted, the first substrate 22 does not necessarily need to be a transparent substrate. For example, a metal substrate such as nickel, titanium, or aluminum, or a semiconductor substrate such as silicon or gallium nitride is used. May be.

  A hard mask layer (not shown) may be formed on one surface 22 a of the first substrate 22. Examples of the material constituting the hard mask layer include metal materials such as Cr, Ti, Ta, and Al, silicon oxide, and the like. The hard mask layer can be formed using a vapor deposition method, a sputtering method, a CVD method, or the like.

  Moreover, the 1st board | substrate 22 may have the convex structure 27 which opposes the uneven structure 14 formed in the master mold 10, so-called mesa structure on the one surface 22a (refer FIG. 8). Thus, the convex structure 27 facing the concave-convex structure 14 of the master mold 10 is formed on the one surface 22a of the first substrate 22, so that a first transfer layer forming step (FIG. 10B) described later is performed. )), The first substrate 22 can be brought into contact only with the concavo-convex structure 14 of the master mold 10 via the material to be transferred 100. Note that the number of steps of the mesa structure (convex structure 27) is not limited to one step, and may be a plurality of steps.

  When the first substrate 22 has a convex structure 27 having a so-called mesa structure, the area Sp defined by the outer shape of the one surface 22a of the first substrate 22 is an area defined by the outer shape of the convex structure 27 having a mesa structure. Instead, it is an area defined by the outermost outer shape of the first substrate 22 (rectangular dimension γ in FIG. 8). The same applies even if the mesa structure (convex structure 27) has a plurality of stages.

  The thickness of the first substrate 22 is not particularly limited, and may be set in consideration of the strength of the substrate, the suitability for handling, and the like, and may be appropriately set within a range of about 300 μm to 10 mm, for example.

Further, the first substrate 22 may have a so-called counterbore structure in which a concave structure 28 is formed on the other surface 22c side facing the one surface 22a (see FIG. 9A). . In this case, the size of the concave structure 28 in plan view is a projection area PA obtained by projecting the area AR ₁ where the first uneven structure on the one surface 22a of the first substrate 22 is to be formed on the other surface 22c side. _It is preferable that 1 is a size physically included in the region defined by the outer shape of the concave structure 28 (see FIG. 9B). Furthermore, the first substrate 22 may have a convex structure 27 formed on one surface 22a and a concave structure 28 formed on the other surface 22c (see FIG. 9C). In this case, the size of the concave structure 28 in plan view is such that the region defined by the outer shape of the convex structure 27 formed on the one surface 22 a of the first substrate 22 is defined by the outer shape of the concave structure 28. It is preferable that the size is physically included in (see FIG. 9D). As described above, by using a substrate having a so-called counterbore structure as the first substrate 22, the copy mold (first mold) 20 constituted by the first substrate 22 is excellent in handleability during imprint processing. It can be.

When the first substrate 22 has the concave structure 28, the thickness Th ₁ of the first substrate 22 in the portion where the concave structure 28 is formed is in the range of 500 to 1500 μm in consideration of the strength and rigidity of the substrate. It can be set appropriately.

  In the imprint mold manufacturing method according to the first embodiment, optical imprinting will be described as an example of imprint processing, but thermal imprinting may be employed as described above.

(Transfer material placement process)
Subsequently, as illustrated in FIG. 10A, the transfer material 100 is disposed on one surface 22 a of the first substrate 22. As the material to be transferred 100, for example, an ultraviolet curable resin can be used. FIG. 10A shows an example in which the material to be transferred 100 is disposed by an ink jet method, but the material to be transferred may be disposed by a known coating method such as a spin coating method. Further, the transfer material 100 may be disposed not on the first substrate 22 side but on one surface 10a of the master mold 10.

(First transfer layer forming step)
Next, as shown in FIG. 10B, the one surface 10 a of the master mold 10 is brought into contact with the material to be transferred 100 on the one surface 22 a of the first substrate 22. Depending on the viscosity of the material to be transferred 100, the material to be transferred 100 is filled into the concavo-convex structure 14 of the master mold 10 by the action of capillary action. If necessary, the master mold 10 or the first substrate 22 may be pressed toward the other surfaces 22a and 10a to assist the filling of the material to be transferred 100 into the concavo-convex structure 14.

  In this way, with the material to be transferred 100 interposed between the master mold 10 and the first substrate 22, the material to be transferred 100 is cured by irradiating ultraviolet light from the first substrate 22 side, so that the concavo-convex structure 14 is formed. A first transfer layer 110 having the transferred first concavo-convex structure pattern 19 is formed.

  As described above, the first substrate 22 may have a convex structure (so-called mesa structure) 27 on one surface 22a thereof. In this case, the master mold 10 and the first substrate 22 are arranged so that the convex structure 27 faces the concave-convex structure 14 of the master mold 10, and the first substrate 22 is a structure to be transferred in the master mold 10. Only the concavo-convex structure 14 is contacted via the material to be transferred 100 (see FIG. 8). In addition, when the 1st board | substrate 22 is comprised as a board | substrate of the mesa structure which has the convex structure 27, the area Sp prescribed | regulated by the external shape of the one surface 22a of the 1st board | substrate 22 is the external shape of the convex structure 27 as a mesa structure. Is an area defined by the outermost outer shape of the first substrate 22 (a rectangle having a dimension γ in FIG. 8). The same applies when the mesa structure has a plurality of stages.

(First peeling step)
Next, as shown in FIG. 10C, after the material to be transferred 100 is cured, the master mold 10 and the first transfer layer 110 are separated. In the separation operation, a force for separation may be applied from either the master mold 10 side or the first substrate 22 side, or a force for separation may be applied from both.

  When applying a separation force to the master mold 10 side, the force may be uniformly transmitted to the first transfer layer 110. However, in order to facilitate the separation, a non-uniform force is applied to the first transfer layer 110. Is preferably transmitted. By transmitting force to the first transfer layer 110 in a non-uniform manner, it is possible to create a starting point of peeling of the master mold 10 (first transfer layer 110), and a smooth peeling operation can be performed from that starting point. The following method can be suitably employed as a peeling method in which force is transmitted non-uniformly to the first transfer layer 110.

(A) The position of the force point for applying a pulling force to the master mold 10 side is adjusted.
A plurality of force points are set at positions on the master mold side at different distances from the outermost periphery of the first transfer layer 110 in a plan view, and a force for pulling is uniformly applied to the plurality of force points. As a result, a separation starting point is generated on a line segment connecting the force point farthest from the outermost periphery of the first transfer layer 110 and the center of gravity of the first transfer layer 110 in plan view. From the starting point of the peeling, the peeling between the master mold 10 and the first transfer layer 110 proceeds gradually.

(B) The alignment position of the master mold 10 and the first substrate 22 is adjusted.
10B to 10C, a concavo-convex structure 14 is formed in the central portion (central portion in plan view) of the master mold 10, and the concavo-convex structure 14 is formed in the central portion (center in plan view) of the first substrate 22. The master mold 10 and the first substrate 22 are disposed so as to be transferred to the portion. That is, in the first transfer layer forming step (see FIG. 10B), the center portions of the master mold 10 and the first substrate 22 substantially coincide with each other in plan view. In contrast, in the first transfer layer forming step (see FIG. 10B), the center portions of the master mold 10 and the first substrate 22 are shifted in plan view. For example, the concavo-convex structure 14 is formed at a position slightly shifted from the central portion of the master mold 10, and the first substrate 22 is arranged so that the concavo-convex structure 14 shifted from the central portion is transferred to the central portion of the first substrate. . Then, when a plurality of force points are set on the outer peripheral portion of the master mold 10, the separation starting point is formed on a line segment connecting the force point farthest from the outermost periphery of the first transfer layer 110 and the center of gravity of the first transfer layer 110 in plan view. Occurs. From the starting point of the peeling, the peeling between the master mold 10 and the first transfer layer 110 proceeds gradually.

(Residual film removal process)
After separating the master mold 10 and the first transfer layer 110, the remaining film portion of the first transfer layer 110 is removed by etching. As a result, as shown in FIG. 10D, a mask 120 made of a cured material of the transfer material is formed on one surface 22a of the first substrate 22.

(First uneven structure forming step)
The first surface 22a of the first substrate 22 is etched using the mask 120 as an etching mask. After the predetermined etching is completed, the mask 120 is removed, and as shown in FIG. 10 (E), the copy mold (first mold) in which the first concavo-convex structure 24 is formed on one surface 22a of the first substrate 22 is shown. Mold) 20 can be manufactured.

  The first concavo-convex structure 24 of the first mold 20 and the concavo-convex structure 14 of the master mold 10 are in a relationship in which concave and convex, and convex and concave are inverted.

  In the imprint mold manufacturing method according to the first embodiment, depending on the material to be transferred 100 used, the remaining film removing step (see FIG. 10D) and the first uneven structure forming step (FIG. 10) are performed. (See (E)) may not be an essential process. As the material to be transferred 100, a polymer whose main chain is composed only of silicon atoms, a solvent, a silicone compound that compatibilizes the polymer and the solvent, and a sensitization that can efficiently insert oxygen between Si-Si bonds of the polymer compound. A material including a hardness adjusting material such as an agent or metal may be used, and the first transfer layer 110 and the first substrate 22 may be combined to form the first mold 20.

  In the first embodiment, as shown in FIG. 11, a second concavo-convex structure 34 (using the first mold 20 obtained as described above and further inverting the first concavo-convex structure 24 of the first mold 20 ( A copy mold (second mold) 30 formed by forming a concavo-convex structure corresponding to the concavo-convex structure 14 of the master mold 10 on the second substrate 32 may be manufactured. A method for manufacturing the copy mold (second mold) 30 will be described below.

(First mold / second substrate preparation process)
As shown in FIG. 11A, the first mold 20 is arranged so that the first concavo-convex structure 24 of the first mold 20 faces one surface 32 a of the second substrate 32. In addition, the 2nd board | substrate 32 is a board | substrate which comprises the copy mold 30 (refer FIG.11 (F)) by which the 2nd uneven structure 34 which reversed the uneven structure 24 of the 1st mold 20 was formed.

  The outer shape of the second substrate 32 may be the same as or different from the outer shape of the first substrate 22 that is the base of the first mold 20. Further, regarding the material constituting the second substrate 32, the thickness thereof, and the like, substantially the same materials as those of the first substrate 22 can be exemplified.

  A hard mask layer (not shown) may be formed on the one surface 32 a side of the second substrate 32. Examples of the material constituting the hard mask layer include metal materials such as Cr, Ti, Ta, and Al, and silicon oxide. The hard mask layer can be formed using a vapor deposition method, a sputtering method, a CVD method, or the like.

  The second substrate 32 may be a substrate having a so-called mesa structure in which a region where the second uneven structure 34 is formed has a convex structure. In this case, it is not limited to having a one-stage convex structure, but may have a plurality of stages of convex structures.

(Transfer material placement process)
Subsequently, as illustrated in FIG. 11B, the transfer material 200 is disposed on the one surface 32 a of the second substrate 32. As the material to be transferred 200, for example, an ultraviolet curable resin can be used. FIG. 11B shows an example in which the material to be transferred 200 is arranged by an ink jet method, but the material to be transferred may be arranged by a known coating method such as a spin coating method. Further, the material to be transferred 200 may be disposed not on the second substrate 32 side but on the surface of the first mold 20 where the first uneven structure 24 is formed (one surface 22a of the first substrate 22). Good.

(Second transfer layer forming step)
Next, as shown in FIG. 11C, the first mold 20 is brought into contact with the material to be transferred 200 on the one surface 32 a of the second substrate 32. Depending on the viscosity of the material to be transferred 200, the material to be transferred 200 is filled into the first concavo-convex structure 24 of the first mold 20 by the action of capillary action. If necessary, the first mold 20 or the second substrate 32 may be pressed to the other surface side to assist the filling of the material to be transferred 300 into the first concavo-convex structure 24.

  In particular, when the first mold 20 (first substrate 22) has a so-called counterbore structure (the other surface 22c is provided with the concave structure 28) (see FIG. 9), the transferred object on the one surface 32a of the second substrate 32 is transferred. When the first mold 20 is brought into contact with the material 200, one side of the second substrate 32 in a state where the first mold 20 is curved so that the one surface 22a side of the first mold 20 (first substrate 22) is convex. Can be brought into contact with the transfer material 200 on the surface 32a (see FIG. 12). Thereby, generation | occurrence | production of the transfer defect by a bubble being taken in into the to-be-transferred material 200 spread on the one surface 32a of the 2nd board | substrate 32 by the contact of the 1st mold 20 can be suppressed.

  In this manner, with the material to be transferred 200 interposed between the first mold 20 and the second substrate 32, the material to be transferred 200 is irradiated with ultraviolet rays from the first mold 20 side or the second substrate 32 side. The second transfer layer 210 having the second uneven structure pattern 29 to which the first uneven structure 24 is transferred is cured.

(Second peeling step)
Next, after the material to be transferred 200 is cured, as shown in FIG. 11D, the first mold 20 and the second transfer layer 210 are separated. In such a separation operation, a force for separation may be applied from one of the first mold 20 side and the second substrate 32 side, or a force for separation may be applied from both.

  In the case of applying a separation force to the first mold 20 side, the force may be uniformly transmitted to the second transfer layer 210, but in order to make the separation easier, the second transfer layer 210 may be unevenly distributed. It is preferable to transmit power. Since the force is transmitted non-uniformly to the second transfer layer 210, a starting point of peeling of the first mold 20 (second transfer layer 210) can be created, and a smooth peeling operation can be performed starting from the starting point. .

  In particular, when the first mold 20 (first substrate 22) has a so-called counterbore structure (including the concave structure 28 on the other surface 22c) (see FIG. 9), the first mold 20 and the second transfer layer 210 are pulled apart. At this time, the first mold 20 and the second transfer layer 210 can be separated while the first mold 20 is curved so that the one surface 22a side of the first mold 20 (first substrate 22) is convex. Thereby, the starting point of the peeling of the first mold 20 (second transfer layer 210) can be created, and a smooth peeling operation can be performed starting from the starting point.

(Residual film removal process)
After separating the first mold 20 and the second transfer layer 210, the remaining film portion of the second transfer layer 210 is removed by etching. Thereby, as shown in FIG. 11E, a mask 220 made of a cured product of the transfer material is formed on one surface 32a of the second substrate 32.

(Second uneven structure forming step)
Using the mask 220 as an etching mask, the one surface 32a of the second substrate 32 is etched. After the predetermined etching is completed, the mask 220 is removed, whereby a copy mold (second mold) in which the second concavo-convex structure 34 is formed on one surface 32a of the second substrate 32 as shown in FIG. Mold) 30 can be manufactured.

  The second concavo-convex structure 34 of the second mold 30 and the concavo-convex structure 14 of the master mold 10 have a relationship in which concave and convex, convex and convex correspond, respectively.

  In the imprint mold manufacturing method according to the first embodiment, depending on the material to be transferred 200 used, the remaining film removing step (see FIG. 11E) and the second uneven structure forming step (FIG. 11). (See (F)) may not be an essential process. As the material to be transferred 200, a polymer whose main chain is composed only of silicon atoms, a solvent, a silicone compound that compatibilizes the polymer and the solvent, and a sensitization capable of efficiently inserting oxygen between the Si-Si bonds of the polymer compound. A material including a hardness adjusting material such as an agent or metal may be used, and the second transfer layer 210 and the second substrate 32 may be combined to form the second mold 30.

  As described above, according to the imprint mold manufacturing method according to the first embodiment, the electron beam lithography is not used for the production of the master mold 10 in a series of manufacturing processes, so that a series of process work time is greatly reduced. It can be shortened. Moreover, since the manufactured 1st mold 20 and 2nd mold 30 can be used with a general imprint apparatus, the productivity improvement of imprint can be expected. Furthermore, since the master mold 10 composed of a large-diameter wafer is used as an imprint mold for producing the first mold 20 without being cut, it maintains the flatness of the wafer. The first transfer layer forming step (see FIG. 10B) can be performed, and more accurate pattern formation is possible.

<Second Embodiment>
Next, an imprint mold manufacturing method according to the second embodiment will be described.
In the imprint mold manufacturing method according to the second embodiment, the uneven structure 14 ′ of the master mold 10 ′ used is substantially formed only by the photolithography method, and the uneven structure 14 ′ is inverted to be the first. The process of transferring to one surface 22a of the substrate 22 is different from the first embodiment in that a side wall method and / or a self-organization method is used, but is otherwise substantially the same as the first embodiment. Therefore, the same reference numerals are given to the same configurations as those of the master mold 10, the first mold 20 (first substrate 22), and the second mold 30 (second substrate 32) in the first embodiment, and detailed description thereof will be given. Is omitted.

  First, unlike the first embodiment, the master mold 10 ′ forms a pattern latent image on a resist film formed on one surface 10a of the wafer 12 by a conventionally known exposure method, and develops it. After the resist pattern Rp is formed (see FIG. 3A), the wafer 12 is selectively etched by a dry etching method using the resist pattern Rp as a mask to form the concavo-convex structure 14 ′.

  A method for manufacturing the first mold 20 using the master mold 10 ′ obtained as described above will be described. FIG. 13 is a process flow diagram showing a process of manufacturing an imprint mold (copy mold, first mold 20) according to the second embodiment in a cross-sectional view.

(Master mold / first substrate preparation process)
First, the master mold 10 ′ is arranged so that the concavo-convex structure 14 ′ formed on the one surface 10a of the master mold 10 ′ faces the one surface 22a of the first substrate 22 (see FIG. 5). As in the first embodiment, the master mold 10 ′ and the first substrate 22 include an area Sm defined by the outer shape of one surface 10 a of the master mold 10 ′ and one surface of the first substrate 22. When compared with the area Sp defined by the outer shape of 22a, the area Sm is physically included in the area Sp (see FIGS. 6 and 7). Moreover, as the 1st board | substrate 22, the thing similar to what was demonstrated in 1st Embodiment can be used.

(Transfer material placement process)
Subsequently, the material to be transferred 100 is disposed on one surface 22a of the first substrate 22 (see FIG. 10A).

(First transfer layer forming step)
Next, as shown in FIG. 13A, the one surface 10a of the master mold 10 ′ is brought into contact with the material to be transferred 100 on the one surface 22a of the first substrate 22. In this manner, with the material to be transferred 100 interposed between the master mold 10 ′ and the first substrate 22, the material to be transferred 100 is cured by irradiating ultraviolet light from the first substrate 22 side, and the concavo-convex structure 14. A first transfer layer 110 ′ having a first concavo-convex structure pattern 19 ′ to which “is transferred is formed.

(First peeling step)
Next, as shown in FIG. 13B, after the material to be transferred 100 is cured, the master mold 10 ′ and the first transfer layer 110 ′ are pulled apart.

(Residual film removal process)
After separating the master mold 10 ′ and the first transfer layer 110 ′, the remaining film portion of the first transfer layer 110 ′ is removed by etching. As a result, as shown in FIG. 13C, a pattern 130 made of a cured product of the material to be transferred 100 is formed on one surface 22a of the first substrate 22.

  Subsequently, a first concavo-convex structure 24 formed by reducing the size of the concavo-convex structure 14 ′ of the master mold 10 ′ is formed on the one surface 22 a of the first substrate 22 by using the sidewall method as follows. To do.

  As shown in FIG. 13D, a slimming process is performed on the pattern 130 formed on the one surface 22a of the first substrate 22 to form a core material C ′ in which the pattern 130 is thinned. The slimming process of the pattern 130 can be performed by, for example, a wet etching method, a dry etching method, a combination thereof, or the like.

  The slimming amount of the pattern 130 is not particularly limited, but the slimming amount is usually set so that the dimension of the core material C ′ is about half that of the pattern 130.

  If the concave-convex structure 14 ′ of the master mold 10 ′ is formed so as to correspond to the concave portion (groove portion) of the core material C ′ shown in FIG. 13D, the above-described slimming treatment (FIG. 13D) is performed. Step) can be omitted.

  Subsequently, as shown in FIG. 13E, a sidewall material film Wm constituting the sidewall pattern Wp is formed on one surface 22a of the first substrate 22 including the core material C ′, and FIG. As shown in FIG. 2, the etching is performed by anisotropic etching such as RIE (Reactive Ion Etching) to form a sidewall pattern (reduced uneven structure) Wp on the sidewall of the core material C ′.

  The sidewall material film Wm can be formed by depositing a sidewall material of a silicon-based material (silicon oxide or the like) by a conventionally known film formation method such as an ALD method (Atomic layer deposition), a CVD method, or a sputtering method. When a resist material is used as the constituent material of the core material C ′ as in the first embodiment, the sidewall material film Wm can be formed at a lower temperature and can be controlled at the atomic layer level by the ALD method. It is desirable to form.

  Since the dimension of the first concavo-convex structure 24 in the first mold 20 depends on the film thickness of the sidewall material film Wm, the film thickness of the sidewall material film Wm depends on the design dimension of the first concavo-convex structure 24. Can be set.

Since the sidewall pattern Wp formed by the etch back is used as an etching mask for the first substrate 22, the height T _WP of the sidewall pattern Wp (the length in the direction parallel to the thickness direction of the first substrate 22). ) Is appropriately set in consideration of the etching selectivity corresponding to the constituent material of the first substrate 22.

  Thereafter, as shown in FIG. 13G, the core material C ′ having the sidewall pattern Wp formed on the sidewalls is removed by ashing (plasma ashing using an oxygen-containing gas or the like). Thereby, only the core material C ′ is removed, and the sidewall pattern Wp can remain on the one surface 22 a of the first substrate 22.

(First uneven structure forming step)
Finally, as shown in FIG. 13H, the first substrate 22 is selectively etched by a dry etching method using the sidewall pattern Wp as a mask to form a first concavo-convex structure 24. Thereby, the copy mold (first mold) 20 in which the first concavo-convex structure 24 is formed on the one surface 22a of the first substrate 22 can be manufactured.

  As described above, by using the side wall method in the process of manufacturing the first mold 20 using the master mold 10 ′ in which the concavo-convex structure 14 ′ is formed by photolithography, the concavo-convex structure 14 ′ of the master mold 10 ′ is used. Thus, it is possible to form the first concavo-convex structure 24 having a reduced size.

  In the second embodiment, the first concavo-convex structure 24 formed by reducing the size of the concavo-convex structure 14 ′ of the master mold 10 ′ by using the self-organization method as follows is used as the first substrate. It may be formed on one surface 22 a of 22.

After forming a pattern 130 made of a cured product of the material to be transferred as shown in FIG. 13D on one surface 22a of the first substrate 22, as shown in FIG. A self-organizing material containing two different components is applied between the patterns 130 and 130 on one surface 22a of the substrate 22 and baked at a predetermined temperature, thereby causing phase separation of the self-organizing material. Since the pattern 130 serves as a guide pattern during phase separation of the self-assembled material, the self-assembled material has a pattern SA ₁ composed of one component having high affinity for the pattern 130 that is the guide pattern. The phase is separated into the pattern SA ₂ composed of the other component, and the patterns SA ₁ and SA ₂ are alternately aligned along the pattern 130.

  As the self-assembling material, a block copolymer composed of two different types of polymers having structures that are difficult to dissolve each other can be used. For example, polystyrene-polymethyl methacrylate (PS-PMMA), polystyrene-polydimethylsiloxane. A block copolymer such as (PS-PDMS) can be used. The two types of polymers constituting the block copolymer are preferably those having different etching resistances (one having high and low etching resistance to a specific etchant).

The dimensions of the patterns SA ₁ and SA ₂ formed by phase separation of the self-assembled material are determined by the molecular weight of the block copolymer as the self-assembled material. Therefore, the molecular weight of the block copolymer used as the self-organizing material can be appropriately set according to the size of the first uneven structure 24 of the first mold 20.

Next, as shown in FIG. 14B, the pattern 130 and the pattern SA ₂ made of the other component are removed by etching, and only the pattern SA ₁ made of one component is on the one surface 22 a of the first substrate 22. To remain.

  Finally, the first substrate 22 is selectively etched by a dry etching method using the pattern 130 as a mask to form the first concavo-convex structure 24 (see FIG. 13H). Thereby, the copy mold (first mold) 20 in which the first concavo-convex structure 24 is formed on the one surface 22a of the first substrate 22 can be manufactured.

  The first concavo-convex structure 24 of the first mold 20 obtained as described above is a convex pattern, and the size is smaller than that of the concavo-convex structure 14 ′ of the master mold 10 ′.

  In the second embodiment, the first mold 20 obtained as described above is used, and the second uneven structure 34 obtained by inverting the first uneven structure 24 of the first mold 20 is formed on the second substrate 32. A copy mold (second mold) 30 may be manufactured. Since the manufacturing method of the copy mold (second mold) 30 is the same as that of the first embodiment, detailed description thereof is omitted (see FIG. 11).

  As described above, according to the imprint mold manufacturing method according to the second embodiment, the electron beam lithography is not used for the production of the master mold 10 ′ in a series of manufacturing processes, so that a series of process work time is greatly increased. Can be shortened. In addition, since the photolithography method and the sidewall method or the self-organization method are used in combination in a series of manufacturing processes, the first mold having the first concavo-convex structure 24 having a size that is difficult or impossible to form by the photolithography method. Contributes to 20 productivity improvements. Furthermore, since the manufactured first mold 20 and second mold 30 can be used in a general imprint apparatus, it is possible to expect an improvement in imprint productivity. Furthermore, since the master mold 10 ′ composed of a large-diameter wafer is used as an imprint mold for manufacturing the first mold 20 without being cut, the flatness of the wafer is maintained. In this state, the first transfer layer forming step (see FIG. 13A) can be performed, and a pattern can be formed with higher accuracy.

<Third Embodiment>
Next, with reference to FIG. 15, the manufacturing method of the imprint mold which concerns on 3rd Embodiment is demonstrated.

  In the imprint mold manufacturing method according to the third embodiment, the master molds 10, 10 ′ and the first substrate 25 are both composed of a silicon single crystal substrate. Then, as shown in FIG. 15, the master mold 10 so that the concavo-convex structure 14, 14 ′ formed on one surface 10 a of the master mold 10, 10 ′ faces the one surface 25 a of the first substrate 25. , 10 ′ and the first substrate 25 are disposed. In FIG. 15, the solid line arrow indicates the crystal direction in which cleavage occurs.

  Further, a dotted line L drawn on the first substrate 25 is shown by projecting a virtual line segment along the crystal direction in which cleavage of the substrate constituting the master mold 10 or 10 ′ occurs to the first substrate 25. Is. Note that the imaginary line segment along the crystal direction in which cleavage occurs means a line segment formed by intersecting the main surface of the substrate and the cleavage plane.

  In the third embodiment, the master molds 10 and 10 ′ and the first substrate 25 are semiconductor wafers having different diameters, and the first substrate 25 is between the master molds 10 and 10 ′. , 10 ′ has a relationship that physically includes the predetermined area Sp of the first substrate 25. Furthermore, in the third embodiment, the first mold 20 is in a state in which imaginary line segments along the crystal direction in which cleavage with respect to the crystal plane orientation of the respective main surfaces of the semiconductor wafers having different diameters are different from each other in plan view. The manufacturing process is performed. Pressing (master molds 10, 10 ′) in the first transfer layer forming step (see FIG. 10B and FIG. 13A) by making the virtual line segments along the crystal direction where cleavage occurs differ from each other in plan view. Or the first substrate 25 is damaged when a separation force is applied in the first peeling step (see FIGS. 10C and 13B). Can be prevented.

  For example, when the various surfaces are silicon single crystals having a crystal orientation {100}, the virtual lines along the crystal direction <110> are made different from each other so that the master molds 10 and 10 ′ and the first substrate 25 face each other. It is preferable to do so. The crystal plane orientation is represented as {100}, which is represented by (100) and represents a plane orientation equivalent to (100) due to the symmetry of the crystal structure. The crystal direction is represented as <100>, which is represented by [100] and represents a direction equivalent to [100] due to the symmetry of the crystal structure.

<Fourth Embodiment>
Next, with reference to FIGS. 16-18, the manufacturing method of the imprint mold which concerns on 4th Embodiment is demonstrated. FIG. 16 is a perspective view showing a master mold in the fourth embodiment, and FIG. 17 is a sectional view taken along line BB in FIG. 16 showing the configuration of the master mold in the fourth embodiment.

  In the imprint mold manufacturing method according to the fourth embodiment, in addition to the relationship that the predetermined area Sm of the master mold 10, 10 ′ physically includes the predetermined area Sp of the first substrate 22, A region where the material to be transferred is easily developed along the surface of the master mold 10 or 10 ′ is set around the concavo-convex structure 14 or 14 ′ of the master mold 10 or 10 ′.

  As shown in FIGS. 16 and 17, on one surface 10a of the wafer 12 constituting the master mold 10, 10 ′, the concavo-convex structure 14, 14 ′, which is a structure for transferring the shape to the material to be transferred, is provided. A first area 16 included inside and a second area 18 existing around the first area 16 are set. The second region 18 is a region where the transfer material is more easily developed along the surfaces of the master molds 10 and 10 ′ than the first region 16.

  The first region 16 and the second region 18 may be arranged separately from each other, or may be adjacent to each other. The arrangement of both the regions 16 and 18 may be appropriately set according to the outer shape and the diameter of the first substrate 22 opposed to the master molds 10 and 10 '.

  Since the second region 18 is a region where the material to be transferred is easily developed, the second region 18 can be a region having better surface wettability than that of the first region 16. For example, the wettability of the surface of the second region 18 can be improved by hydrophilizing the surface of the second region 18. Specifically, at least the second region 18 of the surface of the wafer 12 is provided with a photocatalyst layer, and by irradiating the photocatalyst layer with light, the water contact angle on the surface of the second region 18 can be reduced. . Further, the surface of the first region 16 may be selectively subjected to a hydrophobic treatment. Specifically, the surface of the first region 16 can be selectively hydrophobized by selectively forming a release agent layer on the surface of the first region 16.

  Further, in order to make the second region 18 a region where the material to be transferred is easily developed, a flow path may be provided in the second region 18. By utilizing the capillary phenomenon due to the flow path, the material to be transferred can be easily developed along the surface of the master mold 10, 10 '. For example, a structure that can take in a material to be transferred, such as a dummy pattern, is also included in the flow path in the fourth embodiment. Such a dummy pattern will be described with reference to FIG. 18A is a perspective view of the master mold 10, 10 ′, and FIG. 18B is a concavo-convex structure 14 formed on one surface 10a of the master mold 10, 10 ′ of FIG. 18A. , 14 ′ is a cross-sectional view taken along line CC in FIG. 18A after the master molds 10, 10 ′ and the first substrate 22 are arranged so as to face one surface 22 a of the first substrate 22.

As shown in FIGS. 18A and 18B, the master mold 10, 10 ′ according to the fourth embodiment has a concavo-convex structure formed on one surface 10a as a structure to be transferred to a material to be transferred. A plurality of dummy patterns 14 '' having the same pattern as the concavo-convex structures 14, 14 'are formed around the 14, 14'. Such a dummy pattern 14 ″ is formed simultaneously with the mask pattern (side wall pattern Wp, pattern SA ₁ etc.) for forming the concavo-convex structure 14, 14 ′ in the process of manufacturing the master mold 10, 10 ′. '' mask pattern (sidewall patterns Wp, pattern SA _1, etc.) for forming a forming a concavo-convex structure 14, 14 by etching 'may be formed with. The etching accuracy of the concavo-convex structures 14, 14 ′ can be improved by forming the dummy patterns 14 ″ together with the concavo-convex structures 14, 14 ′ during this etching. Further, the formed dummy pattern 14 '' can be used as a flow path for taking in the material to be transferred.

  FIG. 18A shows a structure in which four dummy patterns 14 ″ are arranged approximately evenly around the concavo-convex structures 14, 14 ′. However, the number and arrangement of dummy patterns 14 ″ are shown. The form is not limited to such an aspect, and various numbers and arrangements can be adopted. Further, the pattern shapes of the concavo-convex structures 14 and 14 ′ and the dummy pattern 14 ″ may be the same or different from each other.

  Further, in FIG. 18B, as a preferred embodiment, the first substrate 22 is a substrate having a convex structure 13 (mesa structure substrate) that can be opposed to the concave and convex structures 14 and 14 ′ formed on the master molds 10 and 10 ′. ). Therefore, in the first transfer layer forming step (see FIGS. 10B and 13A), the first substrate 22 has the material 100 to be transferred only on the concavo-convex structures 14 and 14 ′ as the structure to be transferred. Will come in contact.

  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 example has been shown in which the concavo-convex structure 14 of the master mold 10 or the first concavo-convex structure 24 of the first mold 20 is formed by a combination of a photolithography method and a sidewall method or a self-organization method. The invention is not limited to such an embodiment, and the concavo-convex structure 14 or the first concavo-convex structure 24 may be formed by combining a photolithography method, a sidewall method, and a self-organization method.

  Further, the concavo-convex structure 14 or the first concavo-convex structure 24 may be formed by repeating the sidewall method or the self-organization method twice or more. In this case, in either of the manufacturing steps of the master mold 10 and the first mold 20, the sidewall method or the self-assembly method may be repeated twice or more, or the manufacturing steps of the master mold 10 and the first mold 20. In each case, the sidewall method or the self-organization method may be performed one or more times. In particular, when it is necessary to perform the sidewall method a plurality of times in order to obtain the target dimensions of the first concavo-convex structure 24 in the first mold 20 from the concavo-convex structure 14 produced by photolithography, the master mold 10 and the first mold By distributing the required number of side wall methods in each of the fabrication steps of the mold 20, it is possible to widen the selection range of the side wall material constituting the side wall pattern Wp.

  In the second embodiment, the size of the concavo-convex structure 14 ′ of the master mold 10 ′ is reduced by combining the first concavo-convex structure 24 of the first mold 20 with a photolithography method and a sidewall method or a self-organization method. However, the present invention is not limited to such an embodiment, and the first uneven structure 24 of the first mold 20 is substantially the same as the uneven structure 14 ′ of the master mold 10 ′. When the second mold 30 is formed using the first mold 20 by using the first mold 20, the second concavo-convex structure 34 having a reduced size is formed by using a sidewall method and / or a self-organization method. It may be formed.

  In the said embodiment, the master mold 10 may be comprised with the wafer which has what is called a counterbore structure.

  The present invention is useful in technical fields that require various fine processing.

10, 10 '... Master mold 12 ... Wafer 13, 27 ... Convex structure (mesa structure, convex part)
14, 14 '... uneven structure 19, 19' ... first uneven structure pattern (first reverse uneven structure)
29 ... 2nd uneven structure pattern (2nd inversion uneven structure)
DESCRIPTION OF SYMBOLS 20 ... 1st board | substrate 24 ... 1st uneven structure 30 ... 2nd board | substrate 34 ... 2nd uneven structure 100,200 ... Transfer material 110,110 '... 1st transfer layer 210 ... 2nd transfer layer

Claims (9)

A first reversing concavo-convex structure in which the concavo-convex structure of the master mold is reversed by interposing a transfer material between one surface of the master mold having the concavo-convex structure and one surface of the first substrate. A first transfer layer forming step of forming one transfer layer;
Separating the first transfer layer and the master mold to obtain the first substrate provided with the first transfer layer;
A reduced concavo-convex structure forming step of forming a reduced concavo-convex structure formed by reducing the size of the first inverted concavo-convex structure in the first transfer layer by a sidewall method and / or a self-organization method;
Using the reduced concavo-convex structure as an etching mask, one surface of the first substrate is etched to form a first concavo-convex structure formed by reducing the size of the concavo-convex structure of the master mold on one surface of the first substrate. Including a process,
The first substrate is a glass substrate;
When the area Sm defined by the outer shape of the one surface of the master mold and the area Sp defined by the outer shape of the one surface of the first substrate are compared, the area Sm physically includes the area Sp. In relation
The method for producing an imprint mold, wherein the uneven structure of the master mold is formed on one surface of the master mold by a photolithography method. The first substrate is configured as a mesa structure substrate having a convex portion on the one surface of the first substrate,
In the first transfer layer forming step, the first transfer layer having the first inverted concavo-convex structure is formed on the convex portion by interposing the material to be transferred between the concavo-convex structure and the convex portion. The method of manufacturing an imprint mold according to claim 1 . 3. The imprint mold according to claim 1, wherein the first substrate is configured such that a thickness of an area portion where the first inverted concavo-convex structure is formed is thinner than thicknesses of other area portions. Manufacturing method. The first substrate, the manufacturing method of the imprint mold according to any one of claims 1 to 3, characterized in that it has a rectangular outer shape. 2. The method according to claim 1, further comprising: forming a first concavo-convex structure by etching the first substrate using the first transfer layer or the reduced concavo-convex structure as a mask to form the first concavo-convex structure on the first substrate. method for manufacturing an imprint mold according to any one of 1 to 4. The material to be transferred is interposed between one surface of the first substrate on which the first uneven structure is formed and one surface of the second substrate, and the first uneven structure of the first substrate is inverted. A second transfer layer forming step of forming a second transfer layer having a second inverted concavo-convex structure,
The imprint mold according to claim 5 , further comprising a second peeling step of separating the second transfer layer and the first substrate to obtain the second substrate having the second transfer layer. Manufacturing method. The master mold, 200 mm wafer or manufacturing process of the imprint mold according to any one of claims 1 to 6, characterized in that it is constituted by larger wafers than. The first substrate, the manufacturing method of the imprint mold according to any one of claims 1 to 7, characterized in that a quartz substrate. In the first transfer layer forming step, the transfer material is dropped on one surface of the master mold or one surface of the first substrate by an inkjet method, and the one surface of the master mold and the first surface are method for manufacturing an imprint mold according to any one of claims 1-8, characterized in that interposing said material to be transferred between one one side of the substrate.

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