JP5532939B2 - Optical imprint mold and optical imprint method using the same - Google Patents

Description

  The present invention relates to an optical imprint mold for transferring and forming a desired line, pattern or the like (hereinafter also referred to as a pattern in the present invention) on a workpiece, and an optical imprint method using the same.

  In recent years, nanoimprint technology has attracted attention as a microfabrication technology. Nanoimprint technology is a pattern formation technology that uses a mold (mold member) in which a fine concavo-convex structure is formed on the surface of a substrate, and transfers the concavo-convex structure to a workpiece to transfer the fine structure at the same magnification (Patent Literature). 1). In such a nanoimprint method, when the mold is pressed against the work piece and when the mold and the work piece are separated, the uneven structure of the mold and the work piece are charged by static electricity between the two. Therefore, when the workpiece is pulled away from the mold, there is a problem that the uneven structure of the workpiece is bent by the repulsive force between the charged charges and the dimensional controllability is deteriorated. In order to solve such a problem, a mold has been developed in which at least a part of the concavo-convex structure of the mold that comes into contact with the workpiece is formed of a conductive layer (for example, Patent Document 2).

  As one method of the nanoimprint technique, an optical imprint method is known. In this optical imprint method, for example, a photocurable resin layer is formed as a workpiece on the substrate surface, and a mold having a desired uneven structure is pressed against the resin layer. In this state, the resin layer is irradiated with ultraviolet rays through the mold to cure the resin layer, and then the mold is separated from the resin layer. Thereby, the uneven structure (pattern) in which the unevenness of the mold is reversed can be formed on the resin layer as the workpiece (for example, Patent Document 3). Such optical imprints are capable of forming nanometer-order fine patterns that are difficult to form with conventional photolithography techniques, and are promising as next-generation lithography techniques. For example, discrete track media, or It is also applied to the manufacture of a magnetic recording medium in a form called patterned media.

US Pat. No. 5,772,905 JP 2004-311514 A Special Table 2002-539604

  Before the nanoimprint mold as described above is manufactured and used for imprinting, the formed concavo-convex structure is inspected. In this inspection, it is necessary to measure the concavo-convex structure on the nanometer order of the mold with high accuracy, and observation using a scanning electron microscope (SEM) is performed. However, in the case of a mold for optical imprinting, unlike the mold for nanoimprinting described above, it is essential to have optical transparency, and generally an uneven structure is formed in an electrically insulating transparent material such as synthetic quartz. Has been. For this reason, since charges are accumulated in the concavo-convex structure (pattern) by the irradiated electron beam, there is a problem that observation by SEM is impossible.

  On the other hand, in the conventional mold for nanoimprint such as Patent Document 2 in which at least a part of the uneven structure of the mold that comes into contact with the workpiece is formed of a conductive layer, the mold is placed on the pallet and passed through the pallet. The SEM observation can be performed by grounding the conductive layer. In other words, the mold is not arranged directly on the stage for SEM observation, but the mold is arranged on the pallet so that the conductive pins provided on the pallet are in contact with the conductive layer, and this pallet is used as the stage for SEM observation. By mounting, the concavo-convex structure of the mold is grounded, and charge accumulation due to electron beam irradiation can be prevented. Therefore, even in the mold for optical imprinting, SEM observation is possible by adopting a structure in which a conductive layer is provided on at least a part of the concavo-convex structure of the mold that comes into contact with the workpiece. However, in the method in which the molds are placed one by one on the pallet in this way, there is a problem that preparation for SEM observation takes time and the mold inspection throughput is low. In particular, the above-mentioned problem is remarkable in molds for discrete track media or patterned media that require inspection at high throughput.

Further, in the conventional optical imprinting method, the mold is held by a vacuum suction chuck or pressed against the resin layer while being held by a mechanical chuck. However, in order to deaerate for the purpose of preventing air bubbles from being trapped between the mold and the resin layer, the above vacuum suction chuck ensures that the mold is held securely when optical imprinting is performed in a reduced pressure or vacuum environment. There was a problem that I could not. Further, for example, a mold for discrete track media or patterned media has a problem that the base material is thin and is easily damaged or deformed by a mechanical chuck.
The present invention has been made in view of the above circumstances, and is a mold for optical imprinting that enables SEM observation, enables high-throughput inspection, and enables high-definition pattern formation. And an optical imprint method using the same.

In order to achieve such an object, the mold for optical imprinting of the present invention comprises a transparent base material, a transparent conductive stopper layer and a conductive light shielding layer located on one surface of the transparent base material, and the transparent conductive material. A transparent conductive pattern which is located on the stopper layer and forms a desired concavo-convex structure, a transparent conductive back layer positioned on the other surface of the transparent substrate, and the conductive light shielding layer and the transparent conductive back layer are electrically connected Front and back connection members to be connected, and the conductive light-shielding layer is located on the same surface of the transparent substrate and is electrically connected without being overlapped with the transparent conductive stopper layer located around the transparent conductive stopper layer. The front and back connecting member is a light-shielding side conductive member positioned so as to cover the entire side of the transparent base, or the front and back connecting member penetrates the transparent base. Penetrating conductive member There, and said transparent substrate, and the like provided with a side light shielding layer configured to cover the entire area of the side.

  As another aspect of the present invention, the transparent conductive back layer located on the other surface of the transparent substrate is configured to cover the entire surface.

The optical imprinting method of the present invention is loaded with any of the above-mentioned optical imprinting molds judged to be good in the inspection by scanning electron microscope observation so that the transparent conductive back layer is in contact with the electrostatic chuck. Applying a predetermined voltage to the electrostatic chuck to hold the mold, and then pressing the transparent conductive pattern side against the workpiece and irradiating the workpiece with light through the mold to cure the workpiece. It was set as the structure which has.

  In the mold of the present invention, the transparent conductive pattern layer, the transparent conductive stopper layer, or the conductive light shielding layer located on the transparent conductive back surface layer via the transparent substrate is a side portion of the transparent substrate. Alternatively, since the transparent conductive back surface layer is electrically connected by the front and back connecting members located inside the transparent base material, the mold is directly placed on the stage for SEM observation even if the transparent base material is electrically insulating. Sometimes it is grounded via the transparent conductive back layer, which prevents the charge from accumulating in the transparent conductive pattern layer or the transparent conductive pattern due to electron beam irradiation during SEM observation. It is no longer necessary to place each of them on a pallet, the preparation for SEM observation can be greatly shortened, and the throughput of the inspection process is improved.

  Further, in the optical imprinting method of the present invention, the mold of the present invention is loaded and held so that the transparent conductive back layer is in contact with the electrostatic chuck, so that the mold is placed on the workpiece in a reduced pressure or vacuum environment. Even in the case of pressing, the mold can be securely held, and the mold is not damaged, deformed, etc., so that high-definition pattern formation can be performed stably.

It is a schematic sectional drawing which shows one Embodiment of the mold for optical imprints of this invention. It is a side view for demonstrating the side part electroconductive member which comprises the mold shown by FIG. It is a schematic sectional drawing which shows other embodiment of the mold for optical imprints of this invention. It is a schematic sectional drawing which shows other embodiment of the mold for optical imprints of this invention. It is a schematic sectional drawing which shows other embodiment of the mold for optical imprints of this invention. It is a schematic sectional drawing which shows other embodiment of the mold for optical imprints of this invention. It is a schematic sectional drawing which shows other embodiment of the mold for optical imprints of this invention. It is a schematic sectional drawing which shows other embodiment of the mold for optical imprints of this invention. It is a schematic sectional drawing which shows other embodiment of the mold for optical imprints of this invention. It is a figure for demonstrating the earthing | grounding when a mold is directly arrange | positioned on the stage for SEM observation. It is process drawing for demonstrating an example of the optical imprint method using the mold for optical imprints of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Mold for optical imprint]
The mold for optical imprinting of the present invention will be described.
(First embodiment)
FIG. 1 is a schematic cross-sectional view showing an embodiment of a mold for optical imprinting according to the present invention. In FIG. 1, a mold 1 of the present invention includes a transparent base material 2, a transparent conductive pattern layer 4 having a desired concavo-convex structure located on one surface 2 a of the transparent base material 2, and the other transparent material 2. The transparent conductive back surface layer 7 located in the surface 2b, and the front and back connection member 8 which electrically connects the transparent conductive pattern layer 4 and the transparent conductive back surface layer 7 are provided.
Incidentally, the transparency or transparency in the present invention means that the light transmittance at a wavelength of 365 nm is 30% or more, and in the present invention, such transparency that the light transmittance is 80% or more is preferable. . In the present invention, the term “conductive” or “conductive” means that the resistivity is less than 1.0 × 10 ⁻³ Ω · cm. In the present invention, the resistivity is 5.0 × 10 ⁻⁴ Ω. -Conductivity such as less than cm is preferred.

  The transparent base material 2 constituting the mold 1 is a base material that can transmit irradiation light for curing a workpiece during light imprinting. Examples of the material include quartz glass, silicate glass, and calcium fluoride. Magnesium fluoride, acrylic glass, Pyrex (registered trademark) glass, blue plate glass, soda glass, BK-7, or any of these laminated materials can be used. The thickness of the transparent substrate 2 can be set in consideration of the depth of the concavo-convex structure of the workpiece, the strength of the substrate, suitability for handling, etc. For example, the thickness is appropriately set in the range of about 0.1 mm to 10 mm. can do. Moreover, the shape of the surfaces 2a and 2b of the transparent base material 2 is not particularly limited, and can be set as appropriate, such as a circle and a rectangle.

  The transparent conductive pattern layer 4 constituting the mold 1 has a desired concavo-convex structure and is a part that is pressed against a workpiece in optical imprinting. The concavo-convex structure of the transparent conductive pattern layer 4 can be appropriately set according to the shape, size, etc. of the pattern to be formed. The transparent conductive pattern layer 4 is made of indium tin oxide (ITO), chromium (Cr), silicon (Si), or molybdenum (Mo) based metal oxide (for example, chromium oxide (CrO), oxidized Molybdenum, etc.), or metal nitrides. The transparent conductive pattern layer 4 is formed by forming a thin film of the above-described material by a vacuum film formation method or the like, then forming a desired resist pattern, and etching the resist pattern to a predetermined depth using the resist pattern as a mask. Can be formed. Further, the thickness of the transparent conductive pattern layer 4 can be set according to the depth of the concave portion of the concave-convex structure required from the pattern to be formed, for example, set to be 5 nm or more thicker than the depth of the concave portion. be able to. If the difference between the thickness of the transparent conductive pattern layer 4 and the depth of the concave portion of the concave-convex structure is less than 5 nm, it is not preferable because it becomes difficult to control the formation of the concave portion by etching.

  The transparent conductive back layer 7 constituting the mold 1 is a layer for enabling grounding when the mold 1 is directly placed on the stage in the inspection of the mold 1 by SEM observation. This is a layer for holding. The material of the transparent conductive back layer 7 is made of indium tin oxide (ITO), chromium (Cr), silicon (Si), molybdenum (Mo), metal oxide (for example, chromium oxide (CrO), oxidation Molybdenum, etc.), or metal nitride. The transparent conductive back layer 7 can be formed by, for example, a vacuum film forming method such as a reactive sputtering method, an ion beam assisted vapor deposition method, or an ion plating method, and controls the reaction amount of oxygen or nitrogen to the metal. Thus, the light transmittance, light reflectance, and conductivity can be controlled. The thickness of the transparent conductive back layer 7 can be appropriately set according to the conductivity and light transmittance of the material, and can be set, for example, in the range of about 1 to 100 nm. When the thickness of the transparent conductive back layer 7 is less than 1 nm, the conductivity may be insufficient, and when it exceeds 100 nm, the light transmittance may be insufficient. In the example shown in FIG. 1, the transparent conductive back layer 7 covers the entire surface 2 b of the transparent substrate 2, and in consideration of holding the mold 1 by an electrostatic chuck, the transparent conductive back layer 7 is thus formed. It is preferable to cover the entire surface 2b of the transparent substrate 2. However, the present invention is not limited to this. For example, when considering only the function of enabling grounding when the mold 1 is directly arranged on the stage, the transparent conductive back layer 7 is formed of the transparent substrate 2. It may be present on a part of the surface 2b.

  The front / back connecting member 8 constituting the mold 1 electrically connects the transparent conductive pattern layer 4 and the transparent conductive back layer 7. In the illustrated example, the side portion located on the side portion 2 c of the transparent substrate 2. The conductive member 8 a is the front / back connection member 8. FIG. 2 is a perspective view of the mold 1 for explaining the side conductive member 8a having such a configuration. In FIG. 2, the side conductive member 8a is indicated by hatching, and the region where the concavo-convex structure of the transparent conductive pattern layer 4 is located is surrounded by a two-dot chain line. As shown in FIG. 2 (A), the side conductive member 8a as the front / back connecting member 8 may be disposed on a part of the side 2c of the transparent substrate 2, and FIG. As shown in B), the transparent substrate 2 may be disposed so as to cover all the side portions 2c. When the side conductive member 8a is disposed on a part of the side portion 2c of the transparent substrate 2, the number of the side conductive members 8a may be plural, and the positions to be disposed are set as appropriate. be able to.

When such a side conductive member 8a has light shielding properties, aluminum (Al), nickel (Ni), cobalt (Co), chromium (Cr), titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (Mo), tin (Sn), zinc (Zn), and other metals, their oxides, nitrides, conductive carbon, etc., sputtering, CVD, vacuum deposition, ion plating It can be formed by a vacuum film forming method such as a ting method. The thickness of the side conductive member 8a can be appropriately set according to the conductivity and light transmittance of the material, and can be set, for example, in the range of about 5 to 100 nm. If the thickness of the side conductive member 8a is less than 5 nm, the light shielding property may be insufficient, and if it exceeds 100 nm, the film formation cost increases, which is not preferable. On the other hand, when the side conductive member 8a does not need to have a light shielding property, it may be made of the material as mentioned in the transparent conductive back layer 7 and formed in the same manner as the transparent conductive back layer 7. Can do.
The light shielding or light shielding property in the present invention means that the light transmittance at a wavelength of 365 nm is 1% or less. In the present invention, the light shielding property such that this light transmittance is 0.1% or less. Is more preferable.

FIG. 3 is a schematic sectional view showing another embodiment of the mold for optical imprinting of the present invention. In FIG. 3, the mold 1 ′ is the same as the mold 1 shown in FIG. 1 except that the front / back connection member 8 is a through conductive member 8 b penetrating the transparent substrate 2. Are given the same member numbers.
The through conductive member 8b as the front / back connecting member 8 constituting the mold 1 'is formed by filling the through hole formed in the transparent substrate 2 with a conductive material, or by forming a conductive layer on the inner wall surface of the through hole. Is. Further, the through conductive member 8b as the front / back connecting member 8 is a member obtained by filling the through groove formed in the transparent base material 2 with a conductive material, or by forming a conductive layer on the inner wall surface of the through groove. Formation of the through hole or the through groove in the transparent substrate 2 can be performed by, for example, an ICP-RIE method through a mask pattern. Moreover, a through-hole or a through-groove can be formed by a sandblast method, a wet etching method, or a femtosecond laser method. Furthermore, a fine hole or a fine groove is formed at a predetermined depth from one surface by any one of the methods described above, and then the opposite surface of the transparent substrate 2 is polished to obtain a fine hole or A through hole or a through groove may be formed by exposing the fine groove. The opening diameter of the through hole or the opening width of the through groove can be set in the range of, for example, 10 to 200 μm, preferably 45 to 55 μm. If the opening diameter or opening width is less than 10 μm, it is difficult to form the through-conductive member 8b in the through-hole or through-groove, and disconnection is likely to occur, and if it exceeds 200 μm, the material filled in the through-hole or through-groove is retained. Is difficult and unfavorable. In addition, the shape of the through-hole or the through-groove is a straight shape having a substantially constant inner diameter or width in the thickness direction in the illustrated example, but is not limited to this, and has a tapered shape with a wide opening diameter or opening width. Further, it may be a shape such that the inner diameter or the width is narrow at the approximate center in the thickness direction.

  The through conductive member 8b is formed in the through hole or through groove by, for example, forming a base conductive thin film in the through hole or through groove by plasma CVD or the like, and then depositing a conductive metal by electrofilled plating. Can be performed. Thereby, the penetration conductive member 8b without a void can be obtained. The penetrating conductive member 8b can be made of a conductive material such as Au, Ag, Cu, Sn, or Ni. Alternatively, the through conductive member 8b can be formed by filling the through hole with a conductive paste. The position and the number of the through conductive members 8b are not particularly limited and can be set as appropriate. Further, when the through conductive member 8b is a member in which the through groove formed in the transparent base material 2 is filled with a conductive material as described above, the through conductive member 8b surrounds the outside of the concavo-convex structure of the transparent conductive pattern layer 4. As such, it may exist continuously.

(Second Embodiment)
FIG. 4 is a schematic sectional view showing another embodiment of the mold for optical imprinting of the present invention. In FIG. 4, the mold 11 has a transparent base material 12, a transparent conductive stopper layer 13 positioned on one surface 12 a of the transparent base material 12, and a desired concavo-convex structure positioned on the transparent conductive stopper layer 13. A transparent conductive pattern 15 formed, a transparent conductive back layer 17 located on the other surface 12b of the transparent substrate 12, a front and back connecting member 18 that electrically connects the transparent conductive stopper layer 13 and the transparent conductive back layer 17, It has.
The transparent substrate 12 constituting the mold 11 can be the same as the transparent substrate 2 constituting the mold 1 described above.

  The transparent conductive stopper layer 13 constituting the mold 11 is a layer that exhibits the function of an etching stop layer when the transparent conductive pattern 15 is formed. Examples of the material of the transparent conductive stopper layer 13 include chromium (Cr), silicon (Si), molybdenum (Mo) oxide, nitride, and molybdenum silicide (MoSi). Further, the transparent conductive stopper layer 13 can be formed by, for example, a vacuum film forming method such as a reactive sputtering method, an ion beam assisted vapor deposition method, or an ion plating method, and controls the reaction amount of oxygen or nitrogen to the metal. Thus, light transmittance, light reflectance, and conductivity can be controlled. The thickness of the transparent conductive stopper layer 13 can be appropriately set according to the conductivity and light transmittance of the material, and can be set, for example, in the range of about 5 to 100 nm. When the thickness of the transparent conductive stopper layer 13 is less than 5 nm, the function as an etching stopper layer may be insufficient, and when it exceeds 100 nm, the light transmittance may be insufficient.

  The transparent conductive pattern 15 constituting the mold 11 is positioned on the transparent conductive stopper layer 13 so as to form a desired concavo-convex structure, and is a portion that is pressed against a workpiece in optical imprinting. The concavo-convex structure of the transparent conductive pattern 15 is composed of a convex portion made of the transparent conductive pattern 15 and a concave portion made of a portion where the transparent conductive stopper layer 13 is exposed. The shape and dimensions of the pattern to be formed It can set suitably according to etc. Such a transparent conductive pattern 15 is made of indium tin oxide (ITO), chromium (Cr), silicon (Si), or molybdenum (Mo) based metal oxide (for example, chromium oxide (CrO), molybdenum oxide). Etc.), or metal nitrides. The transparent conductive pattern 15 is formed by forming a thin film of the above-described material on the transparent conductive stopper layer 13 by a vacuum film formation method or the like, and then forming a desired resist pattern on the thin film. Using this resist pattern as a mask, It can form by etching so that the transparent conductive stopper layer 13 may be exposed. Moreover, the thickness of the transparent conductive pattern 15 can be set according to the depth of the recessed part of the uneven structure requested | required from the pattern of the formation objective.

The transparent conductive back layer 17 constituting the mold 11 can be the same as the transparent conductive back layer 7 constituting the mold 1 described above.
The front / back connecting member 18 constituting the mold 11 electrically connects the transparent conductive stopper layer 13 and the transparent conductive back layer 17, and in the illustrated example, the side portion located on the side portion 12 c of the transparent substrate 12. The side conductive member 18a is the same as the side conductive member 8a constituting the mold 1 described above.
Further, the front and back connecting member 18 may be a through conductive member 18b penetrating through the transparent substrate 12 like a mold 11 'shown in FIG. The penetrating conductive member 18b constituting the mold 11 'can be the same as the penetrating conductive member 8b constituting the mold 1' described above.

(Third embodiment)
FIG. 6 is a schematic sectional view showing another embodiment of the mold for optical imprinting of the present invention. In FIG. 6, the mold 21 of the present invention includes a transparent base material 22, a transparent conductive pattern layer 24, a conductive light shielding layer 26, and a transparent base material 22 which are located on one surface 22 a of the transparent base material 22 and have a desired uneven structure. The transparent conductive back surface layer 27 located on the other surface 22b of the material 22 and the front and back connecting member 28 for electrically connecting the conductive light shielding layer 26 and the transparent conductive back surface layer 27 are provided. The conductive light shielding layer 26 is located around the transparent conductive pattern layer 24.
The transparent base material 22 constituting the mold 21 can be the same as the transparent base material 2 constituting the mold 1 described above.

The transparent conductive pattern layer 24 constituting the mold 21 is not located on the entire surface of the one surface 22a of the transparent substrate 22, but the above-described mold 1 except that the conductive light shielding layer 26 is present around the transparent conductive pattern layer 24. The transparent conductive pattern layer 4 that constitutes can be the same as that of the transparent conductive pattern layer 4, and the description thereof is omitted here.
The conductive light-shielding layer 26 constituting the mold 21 is a layer for preventing light from being irradiated to a portion that does not require irradiation of the workpiece by light irradiation in optical imprinting. Such a conductive light shielding layer 26 includes, for example, aluminum (Al), nickel (Ni), cobalt (Co), chromium (Cr), titanium (Ti), tantalum (Ta), tungsten (W), and molybdenum (Mo). , Tin (Sn), zinc (Zn), and other metals, oxides, nitrides, conductive carbon, and the like, or two or more thereof. The conductive light shielding layer 26 can be formed by, for example, a vacuum film forming method such as a sputtering method, a CVD method, a vacuum vapor deposition method, or an ion plating method. The thickness of the conductive light-shielding layer 26 can be appropriately set according to the conductivity and light transmittance of the material, and can be set, for example, in the range of about 5 to 100 nm. If the thickness of the conductive light-shielding layer 26 is less than 5 nm, the light-shielding property may be insufficient, and if it exceeds 100 nm, the film formation cost increases, which is not preferable.

The transparent conductive back layer 27 constituting the mold 21 can be the same as the transparent conductive back layer 7 constituting the mold 1 described above.
The front / back connecting member 28 constituting the mold 21 electrically connects the conductive light-shielding layer 26 and the transparent conductive back surface layer 27. In the illustrated example, the side conductive member located on the side part 22 c of the transparent substrate 22 is used. This is the member 28a, and the side conductive member 28a can be the same as the side conductive member 8a constituting the mold 1 described above. In particular, the mold 21 is provided with the conductive light shielding layer 26 for the purpose of preventing unnecessary light irradiation to the workpiece as described above. In order to achieve this purpose more reliably, the side conductive member is provided. It is preferable that 28a has light-shielding properties. In this case, similarly to the case where the side conductive member 8a has light shielding properties, the side conductive member 28a has light shielding properties and is provided on the entire surface of the side portion 22c of the transparent substrate 22. be able to. Further, the conductive light shielding layer 26 and the side conductive member 28a may be formed of the same material and formed in the same film forming process.

  Further, the front and back connecting member 28 may be a through conductive member 28b penetrating the transparent base material 22 as in a mold 21 'shown in FIG. The penetrating conductive member 28b constituting the mold 21 'can be the same as the penetrating conductive member 8b constituting the mold 1' described above. As described above, the mold 21 ′ includes the conductive light shielding layer 26 for the purpose of preventing light irradiation to a portion that does not require irradiation of the workpiece. In order to achieve this purpose more reliably, A side light shielding layer 29 (shown by two-dotted oblique lines in FIG. 7) may be provided on the entire surface of the side portion 22c of the transparent base material 22. The side light shielding layer 29 may be the same as the above-described side conductive member 28a in the case of providing light shielding properties, and the electrical connection between the conductive light shielding layer 26 and the transparent conductive back layer 27 is a through conductive member 28b. Therefore, the side light shielding layer 29 may be conductive or electrically insulating. In this case, examples of the material of the side light-shielding layer 29 include known compositions used for forming a black matrix of a color filter. For example, black matrix formation described in JP-A-2009-14584 Compositions can be used.

(Fourth embodiment)
FIG. 8 is a schematic cross-sectional view showing another embodiment of the mold for optical imprinting of the present invention. In FIG. 8, the mold 31 is positioned on the transparent base material 32, the transparent conductive stopper layer 33, the conductive light shielding layer 36, and the transparent conductive stopper layer 33 that are located on one surface 32 a of the transparent base material 32. The front and back connecting member for electrically connecting the transparent conductive pattern 35 having the concavo-convex structure, the transparent conductive back layer 37 positioned on the other surface 32b of the transparent base 32, the conductive light shielding layer 36 and the transparent conductive back layer 27. 38. The conductive light shielding layer 36 is located around the transparent conductive stopper layer 33.
The transparent base material 32 constituting the mold 31 can be the same as the transparent base material 2 constituting the mold 1 described above.

The transparent conductive stopper layer 33 constituting the mold 31 is not located on the entire surface 32a of the transparent substrate 32, and the mold 11 described above except that the conductive light shielding layer 36 is present around the transparent conductive stopper layer 33. Can be the same as the transparent conductive stopper layer 13 constituting, and the description thereof is omitted here.
The conductive light-shielding layer 36 constituting the mold 31 is a layer for preventing light from being irradiated to a portion that does not require irradiation of the workpiece by light irradiation in optical imprinting. Such a conductive light shielding layer 36 can be the same as the conductive light shielding layer 26 constituting the mold 21 described above.
The transparent conductive pattern 35 constituting the mold 31 can be the same as the transparent conductive pattern 15 constituting the mold 11 described above.

  The front / back connecting member 38 constituting the mold 31 electrically connects the conductive light shielding layer 36 and the transparent conductive back surface layer 37. In the illustrated example, the side conductive member located on the side part 32 c of the transparent substrate 32 is used. The side conductive member 38a is the member 38a, and can be the same as the side conductive member 8a constituting the mold 1 described above. In particular, as described above, the mold 31 includes the conductive light shielding layer 36 for the purpose of preventing light irradiation to a portion that does not require irradiation of the workpiece, and in order to achieve this purpose more reliably, The partial conductive member 38a preferably has a light shielding property. In this case, similarly to the case where the side conductive member 8a has light shielding properties, the side conductive member 38a has light shielding properties and is provided on the entire surface of the side portion 32c of the transparent substrate 32. be able to. Further, the conductive light shielding layer 36 and the side conductive member 38a may be formed of the same material and formed in the same film forming process.

  Further, the front and back connecting member 38 may be a through conductive member 38b penetrating through the transparent base material 32, as in a mold 31 'shown in FIG. The penetrating conductive member 38b constituting the mold 31 'can be the same as the penetrating conductive member 8b constituting the mold 1' described above. As described above, the mold 31 ′ is provided with the conductive light shielding layer 36 for the purpose of preventing unnecessary light irradiation to the workpiece, and in order to achieve this purpose more reliably, a transparent base material is provided. A side light shielding layer 39 (indicated by a two-dot oblique line in FIG. 9) may be provided so as to cover the 32 side portions 32c. Such a side light shielding layer 39 can be the same as the side light shielding layer 29 in the mold 21 ′ described above.

The above-described molds 1, 1 ', 11, 11', 21, 21 ', 31, 31' of the present invention have transparent conductive back layers 7, 17, 27 by front and back connecting members 8, 18, 28, 38, respectively. , 37 and the transparent conductive pattern layer 4 positioned through the transparent base materials 2, 12, 22, 32, or the transparent conductive stopper layer 13, or the conductive light shielding layers 26, 36. Are electrically connected. Therefore, even if the transparent base materials 2, 12, 22, and 32 are electrically insulating, for example, as shown in FIG. 10, when the mold 1 is directly placed on the stage 41 for SEM observation, the transparent conductive back layer 7 to be grounded. This prevents charges from being accumulated in the transparent conductive pattern layers 4 and 24 and the transparent conductive patterns 15 and 35 due to electron beam irradiation during SEM observation. Therefore, it is not necessary to install the molds one by one on the pallet for the purpose of grounding, the preparation for SEM observation can be greatly shortened, and the throughput of the inspection process is improved.
The above-described embodiment is an exemplification, and the present invention is not limited to this.

[Optical imprint method]
The optical imprint method of the present invention will be described with reference to FIG. 11 by taking as an example the case of using the above-described mold 1 of the present invention.
In the optical imprint method of the present invention, first, the mold 1 of the present invention is loaded so that the transparent conductive back layer 7 contacts the electrostatic chuck 51, and a predetermined voltage is applied to the electrostatic chuck 51 to hold the mold 1. (FIG. 11A). In the illustrated example, the workpiece 61 includes a magnetic layer 63 made of a magnetic material such as iron, an iron alloy, cobalt, or a cobalt alloy on a substrate 62 made of a material such as aluminum, glass, silicon, or quartz. Then, a laminated substrate provided with the photocurable resin layer 64 so as to cover the magnetic layer 63 is prepared.

Next, the transparent conductive pattern layer 4 of the mold 1 is pressed against the photocurable resin layer 64 of the workpiece 61, and the photocurable resin layer 64 is irradiated with light through the mold 1 to be cured (FIG. 11B). )). Thereafter, by releasing the mold 1, a resin layer 64 ′ having a concavo-convex structure obtained by inverting the concavo-convex structure of the mold 1 is obtained (FIG. 11C). In the example of the workpiece 61, a pattern can be formed by dry etching the magnetic layer 63 using the resin layer 64 ′ as a mask (FIG. 11D).
Here, the optical imprint method of the present invention has been described by taking the case of using the above-described mold 1 of the present invention as an example, but the same applies to the case of using the mold of the present invention of another embodiment.

In such an optical imprinting method of the present invention, the mold of the present invention is loaded and held so that the transparent conductive back layer is in contact with the electrostatic chuck, so that the mold is securely held even under reduced pressure or in a vacuum environment. And the mold is not damaged or deformed. Therefore, it is possible to perform optical imprinting in a reduced pressure or vacuum environment in which deaeration is performed for the purpose of preventing trapping of bubbles between the mold and the resin layer, and high-definition pattern formation can be stably performed. .
The above-described embodiment is an exemplification, and the present invention is not limited to this.

Next, the present invention will be described in more detail by showing more specific examples.
[Example]
<Mold production>
A mold of the present invention as shown in FIG. 8 was produced as follows.
First, a synthetic quartz wafer (diameter 150 mm) having a thickness of 0.625 mm was prepared as a transparent base material used for a mold for optical imprinting.
An indium tin oxide (ITO) thin film (thickness 30 nm) was formed on one surface of the transparent substrate by a reactive sputtering method to form a transparent conductive back layer.
The light transmittance of this transparent conductive back layer was 95%, confirming that it had good transparency. The light transmittance was measured using a light transmittance meter (MCPD manufactured by Otsuka Electronics Co., Ltd.).
Moreover, the resistivity of the transparent conductive back layer was 3.5 × 10 ⁻⁴ Ω · cm, and it was confirmed that the transparent conductive back layer had good conductivity. The resistivity was measured using a resistivity measuring device.

Next, molybdenum silicide (thickness 5 nm) was formed on the opposite surface of the transparent substrate by a reactive sputtering method to obtain a transparent conductive stopper layer. As a result of measuring the light transmittance and resistivity of the transparent conductive stopper layer in the same manner as described above, the light transmittance was 87% and the resistivity was 2.2 × 10 ⁻⁵ Ω · cm. It was confirmed that the film had good transparency and conductivity.
Next, a commercially available photosensitive resist is applied onto the transparent conductive stopper layer, exposed through a desired mask, and developed to form a resist pattern with a size of 20 mm × 20 mm in the central portion of the transparent conductive stopper layer. did. Using this resist pattern as a mask, the transparent conductive stopper layer exposed to the periphery was removed by dry etching.

Next, a chromium thin film (thickness: 100 nm) was formed by sputtering while leaving this resist pattern, and then the resist pattern was removed. As a result, a conductive light shielding layer was formed on the transparent substrate so as to surround the transparent conductive stopper layer, and side conductive members as front and back connecting members were formed on the side portions of the transparent substrate. As a result of measuring the light transmittance and the resistivity of the conductive light shielding layer and the side conductive member in the same manner as described above, the light transmittance was less than 0.1%, and the resistivity was 5.0 × 10. ^{It was -5} Ω · cm, and it was confirmed that the film had good light shielding properties and conductivity.
Next, a transparent conductive film (thickness: 100 nm) of indium tin oxide (ITO) was formed on the transparent conductive stopper layer by a pattern vacuum film formation method through a desired mask. About this transparent conductive film, the light transmittance and the resistivity were measured in the same manner as described above. As a result, the light transmittance was 80%, and the resistivity was 3.5 × 10 ⁻⁴ Ω · cm. It confirmed that it had favorable transparency and electroconductivity.

Next, a commercially available photosensitive resist was applied onto the transparent conductive film, and was exposed and developed by electron beam drawing to form a resist pattern having an LS pattern with a pitch of 100 nm and a pattern width of 50 nm. Using this resist pattern as a mask, the above transparent conductive stopper layer was used as an etching stop layer, and the transparent conductive film was dry etched under the following conditions to form a transparent conductive pattern.
(Dry etching conditions)
・ Etching gas: HI
・ Gas flow rate: 50sccm
・ Chamber pressure: 6.5Pa
・ Input RF power: 100W
Thereby, the mold of the present invention as shown in FIG. 8 was obtained.

<Mold inspection>
As a result of placing the above mold on the stage of SEM and performing SEM observation, a clear image is obtained, the pitch of the concavo-convex structure of the above transparent conductive pattern is 100 nm, and the size of the mask used is high. It was confirmed that it was reproduced with accuracy.
<Confirmation of holding by electrostatic chuck>
The mold was held by applying a voltage of 500 V to the electrostatic chuck of the optical imprint apparatus. Thereafter, the chamber was decompressed to 10 Pa, but the mold was securely held by the electrostatic chuck.

[Comparative example]
<Mold production>
A synthetic quartz wafer similar to that of Example 1 was prepared, a commercially available photosensitive resist was applied onto the synthetic quartz wafer, and exposure and development were performed by electron beam drawing, and a resist pattern of an LS pattern having a pitch of 100 nm and a pattern width of 50 nm. Formed. Using this resist pattern as a mask, a synthetic quartz wafer was dry etched under the following conditions to form a concavo-convex structure to produce a mold.
(Dry etching conditions)
Etching gas: CF ₄
・ Gas flow rate: 100sccm
・ Chamber pressure: 3.0Pa
・ Input RF power: 300W

<Mold inspection>
As a result of SEM observation of the mold described above in the same manner as in Example 1, a clear image was not obtained and the mold could not be inspected.

  It can be used for various fine processing, fine pattern formation, etc. using optical imprint technology.

1, 1 ', 11, 11', 21, 21 ', 31, 31' ... Optical imprint mold 2, 12, 22, 32 ... Transparent base material 13, 33 ... Transparent conductive stopper layer 4, 24 ... Transparent Conductive pattern layer 15, 35 ... Transparent conductive pattern 7, 17, 27, 37 ... Transparent conductive back layer 8, 18, 28, 38 ... Front / back connection member 8a, 18a, 28a, 38a ... Side conductive member 8b, 18b, 28b , 38b ... penetrating conductive member 26, 36 ... conductive light shielding layer 29, 39 ... side light shielding layer

Claims (3)

A transparent base material, a transparent conductive stopper layer and a conductive light-shielding layer located on one surface of the transparent base material, a transparent conductive pattern located on the transparent conductive stopper layer to form a desired concavo-convex structure, and the transparent base A transparent conductive back layer located on the other surface of the material, and a front and back connection member that electrically connects the conductive light shielding layer and the transparent conductive back layer,
The conductive light shielding layer is located on the same surface of the transparent substrate and is electrically connected without being overlapped with the transparent conductive stopper layer located around the transparent conductive stopper layer,
The front / back connecting member is a light-shielding side conductive member positioned so as to cover the entire side of the transparent base, or the front / back connecting member penetrates the transparent base. A mold for optical imprinting, wherein the mold is a penetrating conductive member, and the transparent base material includes a side light-shielding layer so as to cover the entire side part.   The mold for optical imprinting according to claim 1, wherein the transparent conductive back layer located on the other surface of the transparent substrate covers the entire surface. The mold for optical imprinting according to claim 1 or 2 determined to be satisfactory in inspection by scanning electron microscope observation is loaded so that the transparent conductive back layer is in contact with an electrostatic chuck, and the electrostatic Applying a predetermined voltage to the chuck to hold the mold, and then pressing the transparent conductive pattern side against the workpiece and irradiating the workpiece with light through the mold to cure the workpiece. A characteristic optical imprint method.

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