JP6056305B2 - Manufacturing method of structure for individual authentication - Google Patents

Description

  The present invention relates to a method for manufacturing a structure for individual authentication that can be used in a technique for performing authentication using characteristics unique to an artificial object.

In recent years, biometrics for authenticating an individual using biometric information unique to each person has been put into practical use in various fields. Biometric information is information that includes physical features such as fingerprints and veins, and behavioral features such as voice and handwriting, and uses such information to authenticate mobile phone and bank card users and log in to computers. It is used in situations such as user authentication. Although biometrics was targeted at humans, a similar method can be applied to individual authentication of objects. This is called artifact artifact metrics. Artifact metrics are techniques for authenticating artifacts using features unique to artifacts. For example, in the financial field, transactions and processing using artifacts such as certificates and cards are performed everywhere, and artifact metrics are considered useful as a means to increase their safety and reliability. Yes.
For example, Patent Documents 1 and 2 are known as conventional techniques using artifact metrics. Patent Document 1 proposes a card to which a chip on which an artificial object made of metal particles is disposed is attached. Patent Document 2 proposes an authenticity identification card to which a chip on which an artificial object made of fiber is disposed is attached.

Japanese Patent Laid-Open No. 10-44650 JP 2003-29636 A

Currently, an IC chip or the like is used to enhance security. For example, if an artificial object having clone resistance that is difficult to counterfeit can be incorporated into an IC card, further improvement in security can be achieved. Expected. As described above, expectations for fine and clone-resistant artifacts are great, but it has been difficult to produce minute clone-resistant artifacts with conventional techniques.
This invention is made | formed in view of the above situations, and it aims at providing the method of manufacturing the structure for an individual authentication which is a fine artificial material with clone resistance.

In order to achieve such an object, the present invention provides a method for manufacturing a structure for individual authentication using an artificial object, a step of forming a resist layer by applying an actinic radiation sensitive resist on a substrate, A step of irradiating a desired portion of the resist layer with actinic radiation to form a latent image of the resist pattern; and a step of developing the resist layer to form a resist pattern. At least one type of tilting, collapsing, and slipping was caused in any direction by applying an external force to at least a part, and at least one kind of leaning, overlapping, and approaching of the separated patterns occurred. A resist structure having one or more three-dimensional pattern aggregates in a state is formed on the substrate.

As another aspect of the present invention, as the external force, the surface tension of the processing liquid in the rinsing process after the development process, the electrostatic force generated by charging by charged particle beam irradiation, the fluid pressure by fluid ejection, the vibration pressure by ultrasonic vibration It was set as the structure which uses at least 1 sort (s) of.
As another aspect of the present invention, the resist structure is formed on the substrate, and then the substrate is etched using the resist structure as a mask to form a concavo-convex structure.
As another aspect of the present invention, after the step of forming the concavo-convex structure, an imprint step of forming a resin layer having the concavo-convex structure on a substrate using the substrate as a mold is employed.
As another aspect of the present invention, in the imprint process, the substrate is etched using the resin layer as a mask to form a concavo-convex structure.

  In the present invention, a resist structure is formed on a substrate, and the resist structure has one or more pattern aggregates formed by applying an external force to at least a part of the resist pattern. Therefore, it is possible to produce a structure for individual authentication which is a fine artificial material having clone resistance.

It is process drawing which shows one Embodiment of the manufacturing method of the structure for individual authentication of this invention. It is a figure for demonstrating the example of a shape of the pattern aggregate which the resist structure which comprises the structure for individual authentication has. It is process drawing which shows other embodiment of the manufacturing method of the structure for individual authentication of this invention. It is a figure for demonstrating the uneven structure formed by etching a base | substrate using a resist structure body as a mask. It is process drawing which shows other embodiment of the manufacturing method of the structure for individual authentication of this invention. It is drawing which shows the result of having observed sample 1-1 to sample 1-10 of Example 1 using SEM. It is drawing which shows the result of having observed sample 2-1 to sample 2-9 of Example 2 using SEM. It is drawing which shows the result of having observed sample 3-1 to sample 3-10 of Example 3 using SEM. It is drawing which shows the result of having observed the sample 3-1 of Example 3 using SEM. It is drawing which shows the result of having observed the sample 3-1 of Example 3 using SEM. It is drawing which shows the result of having observed the sample 3-1 of Example 3 using SEM. It is drawing which shows the result of having observed the sample 3-1 of Example 3 using SEM. It is drawing which shows the result of having observed the sample 3-1 of Example 3 using SEM.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that the drawings are schematic or conceptual, and the dimensions of each member, the ratio of sizes between the members, etc. are not necessarily the same as the actual ones, and represent the same members. However, in some cases, the dimensions and ratios may be different depending on the drawing.

[First Embodiment]
FIG. 1 is a process diagram showing an embodiment of a method for producing an individual authentication structure according to the present invention.
This embodiment is a method of manufacturing an individual authentication structure having a resist structure on a substrate. First, an actinic radiation sensitive resist is applied on one surface 2 a of the substrate 2 to form a resist layer 11. Is formed (FIG. 1A).
The substrate 2 to be used can be appropriately selected in consideration of characteristics required for the individual authentication structure to be manufactured, for example, strength characteristics, electrical characteristics, optical characteristics, etc., for example, quartz glass or soda lime glass, Glass such as borosilicate glass, semiconductors such as silicon, silicon oxide, silicon nitride, gallium arsenide, gallium nitride, chromium, tantalum, aluminum, nickel, titanium, copper, iron, cobalt, tin, beryllium, gold, silver, platinum, Metal substrates such as palladium and amalgam and metal stays, resin substrates and resin films such as polycarbonate, polypropylene, and polyethylene, or composites made of any combination of these materials can be used. Also, as will be described later, other structures such as fine wiring used in semiconductor devices and displays, photonic crystal structures, optical waveguides, and the like are formed in a region other than the region where the resist structure is formed. The formed substrate may be used as the substrate 2.

As the actinic radiation sensitive resist to be used, known negative and positive resists that can be sensitive to desired actinic radiation such as electron beams, X-rays, and ultraviolet rays can be used. The negative resist composition described in 2009/060869 can be preferably used. The thickness of the resist layer 11 to be formed is set so that a pattern aggregate can be formed in the subsequent process in consideration of the physical strength of the resist to be used and the shape, size, pitch, etc. of the resist pattern formed in the subsequent process. For example, it can be set within a range of 10 to 500 nm.
Next, a desired portion of the resist layer 11 is irradiated with actinic radiation to form a resist pattern latent image 11 '(FIG. 1B). As the actinic radiation to be used, for example, an electron beam, an X-ray, an ultraviolet ray or the like can be used according to the sensitivity of the resist layer 11.
Next, the resist layer 11 is developed to form a resist pattern 5 (FIG. 1C), and an external force is applied to at least a part of the resist pattern 5 to form one or more pattern aggregates 6. As a result, a resist structure 3 is formed on one surface 2a of the base body 2 to form an individual authentication structure 1 (FIG. 1D). Here, the pattern aggregate 6 is a state in which at least one type of deformation such as inclination, collapse, or slip occurs in the resist pattern 5 and the separated patterns lean against each other, overlap, and approach. The three-dimensional structure. In the present invention, since the resist pattern 5 is formed by actinic lithography, the resist pattern 5 can be selectively formed in a specific region where an individual authentication structure is desired.

The resist pattern 5 before the external force is applied may be composed of a plurality of pillar-shaped patterns such as a cylinder or a prism, a line / space pattern, a combination thereof, or the like. In any direction, at least one type of deformation such as tilting, collapsing, and sliding can occur at any degree. For example, when the resist pattern 5 has a plurality of pillar-shaped patterns, the pattern thickness, aspect ratio (height to bottom width ratio), and pitch can be appropriately set so that the above-described deformation can occur. Further, when the resist pattern 5 has a line / space pattern, the size of the line and the space and the aspect ratio of the line (ratio of the height and the bottom width) can be appropriately set so that the above-described deformation can occur. In the line / space pattern, the line may be discontinuous, and the line may be easily deformed by an external force.
The external force applied to the resist pattern 5 is, for example, the surface tension of the processing liquid in the drying process of the rinsing process performed after the development process, the electrostatic force generated by charging by charged particle beam irradiation, the fluid pressure by fluid ejection, or the ultrasonic vibration. A vibration pressure etc. can be mentioned, At least 1 sort (s) of these can be used. According to these methods, it is possible to easily cause the resist pattern 5 to be inclined, tilted, or slipped so as to be difficult to reproduce artificially. As a result, the shape of the pattern aggregate 6 having a three-dimensional structure is extremely low in reproducibility.

Among such external forces, the surface tension of the processing liquid in the rinsing process after the developing process exists between patterns in the drying process of the rinsing process for removing the developing solution from the resist pattern 5 formed by the developing process. This is the force acting from the rinse liquid (mainly ultrapure water). In the drying process of the rinsing process at the time of forming the resist pattern 5 shown in FIG. 1C, the force σ acting from the rinsing liquid existing between the patterns at close positions is expressed by the following equation.
σ = 6γcosθ (H / W) ² / D
γ: Surface tension of rinse solution
θ: Contact angle between rinse solution and pattern
H: Pattern height
W: Pattern width
D: Pattern interval

When the rinsing liquid is dried, a force σ acting between the rinsing liquid and the pattern is generated, and when this force σ is larger than the adhesive force between the resist pattern 5 and the substrate 2, the pattern is inclined, falls, and slips. As a result, a pattern structure 3 having a pattern aggregate 6 as shown in FIG.
The plurality of patterns of the resist pattern 5 have the same design values for the height H, the pattern width W, and the pattern spacing D, but the individual pattern height H, the pattern width W, and the pattern spacing. There is variation in D. For this reason, in the drying process of the rinsing process, the force σ acting between the patterns by the rinsing liquid influences the force σ acting between other patterns located in the vicinity, and the force σ acting for each pattern is large. The direction is slightly different. In addition, the magnitude and direction of the force σ are slightly different depending on the drying conditions of the rinsing liquid. Therefore, the shape of the pattern aggregate 6 which is a three-dimensional structure in which at least one kind of leaning, overlapping, and approaching has occurred on a plurality of separated patterns has extremely low reproducibility. Thus, the individual authentication structure 1 provided with the resist structure 3 on the substrate 2 has excellent clone resistance. The individual authentication can be performed by recognizing and identifying the three-dimensional structure of the resist structure 3. Individual authentication can also be performed by recognizing and recognizing the planar view shape of the pattern aggregate 6 having a three-dimensional structure. Also in this case, the resolution limit of the electron beam lithography is included in the structure of the pattern aggregate 6 that is a three-dimensional structure in which at least one of the resist patterns that have been separated from each other is leaning, overlapping, and approaching. Since there is a pattern interval that is below (for example, 20 nm or less), a pattern shape that is below the resolution limit of electron beam lithography also appears in the planar view shape of the pattern aggregate 6. Therefore, it is extremely difficult to forge the shape of the pattern aggregate 6 in plan view.

FIG. 2 is a diagram for explaining an example of the shape of the pattern aggregate 6 formed by deformation of the resist pattern, using two patterns. The pattern aggregate 6 shown in FIG. 2 (A) has a shape in which the patterns 5 at close positions are inclined and lean against each other. Further, the pattern aggregate 6 shown in FIG. 2B has a shape in which the pattern 5 at the close position collapses and partially overlaps. Further, the pattern aggregate 6 shown in FIG. 2C has a shape in which one of the patterns 5 in the close position slips and leans toward the other. Further, the pattern aggregate 6 shown in FIG. 2D has a shape in which one of the resist patterns 5 at the close position collapses and slides toward or comes into contact with the other.
In FIG. 2, the shape of the pattern aggregate 6 by the two patterns 5 in the close position is shown. However, the number of the patterns 5 constituting one pattern aggregate 6 may be three or more. The shape of the aggregate 6 may be a combination of the above shapes. The shape of the pattern aggregate 6 is not limited to the illustrated example.
Since the force acting from the rinse liquid in the drying process of the rinse treatment as described above acts on the entire area of the resist pattern 5, the resist structure 3 has one pattern aggregate 6 over the entire area of the resist pattern 5, that is, All patterns may have one pattern aggregate 6 formed by at least one kind of deformation such as tilt, fall, slip, etc., and a plurality of pattern aggregates 6 and these The pattern aggregate 6 may have a region where the pattern is not deformed.

In this embodiment, for example, the resist pattern 5 shown in FIG. 1C is charged by irradiating a charged particle beam such as an electron beam or an ion beam, and electrostatic force generated between the patterns is applied to the resist pattern 5. It can be used as an external force to give. Further, an external force that applies to the resist pattern 5 a force (fluid pressure) that acts by injecting a fluid such as gas onto the resist pattern 5 shown in FIG. 1C while changing the strength, direction, area, etc. of the injection. Can be used as Furthermore, the vibration pressure transmitted by placing the resist pattern 5 in a liquid such as ultrapure water and applying ultrasonic vibration to the liquid can be used as an external force applied to the resist pattern 5. Such an external force is useful for forming the pattern aggregate 6 on the resist pattern 5 that does not cause any deformation such as inclination, tilting, and slipping in the rinsing process.
Moreover, you may combine at least 1 type of such external force, and the force which acts from the rinse liquid in the drying process of said rinse process. In this case, in addition to at least one kind of deformation such as tilt, falling, slipping, etc. caused in the rinsing process, further deformation can be imparted, and the structure of the pattern aggregate 6 can be made more complicated. The number and area of the pattern aggregates 6 can be controlled.

In the first embodiment as described above, the resist structure 3 is formed on the substrate 2 to form the individual authentication structure 1, and the resist structure 3 is formed by applying an external force to at least a part of the resist pattern 5. The pattern aggregate 6 has one or more of the above-described pattern aggregates 6. The pattern aggregates 6 exhibit clone resistance that is difficult to counterfeit. Therefore, by making the resist pattern 5 as fine as desired, it is possible to manufacture a structure for individual authentication that is a fine artificial object having clone resistance.
In the present embodiment, the individual authentication structure 1 including the resist structure 3 on the base 2 is diced into a chip having a desired size, for example, a chip having a size of 2 μm square to 100 μm square, and individual authentication is performed. It may be manufactured as a structure for individual authentication that can be incorporated into other objects requiring the above.
Further, an alignment mark for individual authentication can be provided on the substrate 2 together with the resist structure 3, and such an alignment mark is also provided for the above-described chip size individual authentication structure. be able to. In the present invention, since actinic lithography is used, it is possible to produce a registration mark and an alignment mark during individual authentication in the same process. The alignment mark has a pattern dimension larger than that of the resist pattern 5 constituting the resist structure 3, thereby providing an external force applied to deform the resist pattern 5 with sufficient adhesion to the base 2. Or it is preferable to comprise so that it may not deform | transform by the external force which acts at the time of use etc.

  The individual authentication structure 1 manufactured as described above includes a base 2 and a resist structure 3 including a plurality of resist patterns 5 positioned on one surface 2a of the base 2, and each resist pattern. 5 and the angle formed by the surface 2a, the inclination direction of the resist pattern 5 in which the angle is less than 90 °, and the interval between the resist patterns 5 are not constant, and the resist pattern 5 leans on and overlaps with each other. One or more pattern aggregates 6 having a three-dimensional structure constituted by at least one approaching state are present in the resist structure 3. Such an individual authentication structure 1 can perform individual authentication using, for example, the contour shape of the resist structure 3 in plan view, the three-dimensional shape of the resist structure 3 in cross section, and the height information of the resist structure 3. It can be carried out.

[Second Embodiment]
FIG. 3 is a process diagram showing another embodiment of the method for producing a structure for individual authentication of the present invention.
This embodiment is a method for manufacturing an individual authentication structure having a concavo-convex structure on a substrate. First, as in the first embodiment described above, a resist structure 3 having one or more pattern aggregates 6 is used. Is formed on one surface 2a of the substrate 2 (FIG. 3A).
Next, the base body 2 is etched using the resist structure 3 as a mask to produce the individual authentication structure 1 ′ having the concavo-convex structure 8 (FIG. 3B). As the etching of the substrate 2, for example, dry etching such as reactive ion etching and reactive gas etching, and physical etching such as ion milling can be performed. Then, by appropriately setting the etching rate of the substrate 2 and the etching rate of the resist structure 3, the uneven structure 8 having various shapes and dimensions can be formed.
FIG. 4 is a diagram for explaining the concavo-convex structure 8 formed by anisotropic dry etching of the substrate 2 using the resist structure 3 as a mask. The pattern aggregate 6 shown in FIG. 2 is used as a mask. It is an example.

The concavo-convex structure 8 shown in FIG. 4A is formed by etching the substrate 2 using a pattern aggregate 6 (shown by a two-dot chain line) having a shape in which the resist patterns 5 are inclined and lean against each other. It is. The pattern aggregate 6 has a portion where the thickness as a mask differs depending on the posture of the resist pattern 5 constituting the pattern aggregate 6. In the pattern aggregate 6 shown in FIG. 4A, the thickness as a mask differs depending on the part as indicated by a chain line arrow perpendicular to the substrate 2. For this reason, in the portion where the thickness of the pattern aggregate 6 as a mask is thin during the etching of the substrate 2, the mask disappears and the etching of the substrate 2 is started. Accordingly, in response to the difference in thickness of the pattern aggregate 6 as a mask, etching of the substrate 2 at the site where the pattern aggregate 6 is located is started with a time difference, and the uneven structure 8 formed at the site has a complicated shape. It will be equipped with. Further, the shape of the concavo-convex structure 8 shown in FIG. 4A can be different from the shape of the illustrated example by setting the etching rate of the substrate 2 and the etching rate of the resist pattern 5.
4B is obtained by etching the substrate 2 using a pattern aggregate 6 (shown by a two-dot chain line) having a shape in which the resist pattern 5 collapses and partially overlaps as a mask. Formed. Also in this case, the concavo-convex structure 8 formed on the substrate 2 at the site where the pattern aggregate 6 is located has a complicated shape corresponding to the difference in thickness of the pattern aggregate 6 as a mask.

Further, the concavo-convex structure 8 shown in FIG. 4C has a pattern aggregate 6 (shown by a two-dot chain line) having a shape in which a slip occurs on one side of the resist pattern 5 and is inclined and leans on the other as a mask. 2 is formed by etching. Also in this case, the concavo-convex structure 8 formed on the substrate 2 at the site where the pattern aggregate 6 is located has a complicated shape corresponding to the difference in thickness of the pattern aggregate 6 as a mask.
Furthermore, the concavo-convex structure 8 shown in FIG. 4D masks the pattern aggregate 6 (shown by a two-dot chain line) having a shape in which one of the resist patterns 5 collapses and slides toward or comes into contact with the other. The substrate 2 is formed by etching. Also in this case, the concavo-convex structure 8 formed on the substrate 2 at the site where the pattern aggregate 6 is located has a complicated shape corresponding to the difference in thickness of the pattern aggregate 6 as a mask.

  In such dry etching of the substrate 2 using the pattern aggregate 6 as a mask, the substrate 2 at the position where the pattern aggregate 6 is located is etched by setting the etching rate of the substrate 2 and the etching rate of the resist pattern 5. Since the start time can be controlled and the degree of disappearance of the pattern aggregate 6 as a mask can be controlled, the uneven structure 8 having various shapes and dimensions can be formed. Even in such a concavo-convex structure 8, there is a pattern shape that is not more than the resolution limit of electron beam lithography. For example, the portion of the concavo-convex structure 8 shown in FIG. 4 (A) having a width W1 and the portion of the concavo-convex structure 8 shown in FIG. 4 (C) having a width W2 can be below the resolution limit of electron beam lithography. As a result, it is extremely difficult to forge a planar view shape obtained by optically identifying the concavo-convex structure 8 included in the individual authentication structure 1 ′ manufactured as in the present embodiment. The individual authentication structure 1 ′ having the uneven structure 8 in 2 has excellent clone resistance. Therefore, individual authentication can be performed by recognizing and identifying the plan view shape of the concavo-convex structure 8. Individual authentication can also be performed by recognizing and identifying the three-dimensional shape and dimensions of the concavo-convex structure 8.

In the second embodiment as described above, the concavo-convex structure 8 is formed on the substrate 2 by etching using the resist structure 3 as a mask to form the individual authentication structure 1 ′, and the concavo-convex structure 8 is difficult to forge. Expresses clone resistance. Therefore, by making a desired fine resist pattern for forming the resist structure 3, it is possible to manufacture a structure for individual authentication, which is a fine artificial object having clone resistance.
In the present embodiment, individual authentication is required by dicing the individual authentication structure 1 ′ having the concavo-convex structure 8 on the base 2 into a chip having a desired size, for example, a chip having a size of 2 μm square to 100 μm square. It may be manufactured as an individual authentication structure that can be incorporated into other objects.
In addition, by forming a mark for alignment at the time of individual authentication on the base body 2 together with the resist structure 3, the base body 2 is provided with a concavo-convex structure as a mark for alignment at the time of individual authentication together with the concavo-convex structure 8. be able to. Such alignment marks can also be provided on the individual authentication structure having the chip size.
The individual authentication structure 1 ′ manufactured as described above includes the base 2 and the concavo-convex structure 8 located on one surface 2 a of the base 2, and the concave portion of the concavo-convex structure 8 in the thickness direction of the base 2. Both the bottom position and the top position of the projection are not constant, and the concavo-convex structure 8 has a recess and / or a protrusion having a width of 20 nm or less. Such an individual authentication structure 1 ′ is obtained by using, for example, individual authentication using a contour shape in plan view of the concavo-convex structure 8, a three-dimensional shape in sectional view of the concavo-convex structure 8, height and depth information of the concavo-convex structure 8 It can be performed.

[Third Embodiment]
FIG. 5 is a process diagram showing another embodiment of the method for manufacturing the structure for individual authentication of the present invention.
This embodiment is a method of manufacturing an individual authentication structure on a desired substrate by an imprint method. First, as in the first embodiment, a resist having one or more pattern aggregates 6 is used. The structure 3 is formed on the base 2, and then the base 2 is etched using the resist structure 3 as a mask to form the concavo-convex structure 8, as in the second embodiment described above, to form the mold 21 (FIG. 5 (A)).
Next, the resin 35 is supplied onto one surface 32a of the desired substrate 32, and the mold 21 and the substrate 32 are brought close to each other to fill the resin 34 into the concavo-convex structure 8 (FIG. 5B). In this state, the resin 34 is cured to form the resin layer 35, and then the mold 21 and the resin layer 35 are released, whereby the resin layer 35 having the concavo-convex structure 36 that is the inverted shape of the concavo-convex structure 8 is formed on the base material 32. To form an individual authentication structure 31 (FIG. 5C).

The substrate 32 to be used is, for example, glass such as quartz glass, soda lime glass, borosilicate glass, semiconductors such as silicon, silicon oxide, silicon nitride, gallium arsenide, gallium nitride, chromium, tantalum, aluminum, nickel, titanium, From metal substrates such as copper, iron, cobalt, tin, beryllium, gold, silver, platinum, palladium, amalgam or metal stays, resin substrates or resin films such as polycarbonate, polypropylene, polyethylene, or any combination of these materials And the like can be used. In addition, for example, a substrate on which fine wiring used for a semiconductor device, a display, or the like, or a structure such as a photonic crystal structure or an optical waveguide is formed may be used.
The resin 34 to be used can be formed using a photo-curing, thermosetting, or thermoplastic resin material. For example, the resin 34 is supplied with droplets of the resin material on the substrate 32, The concavo-convex structure 8 can be filled with the resin 34 by causing the droplets of the resin 34 to spread by bringing the mold 32 and the mold 21 close to each other. Of course, resin material droplets may be supplied onto the mold 21.

  The individual authentication structure 31 manufactured in this way has a concavo-convex structure 36 in which the resin layer 35 is an inverted shape of the concavo-convex structure 8, and as described above, the resolution limit of electron beam lithography in the concavo-convex structure 8. Since the following pattern shapes exist, the concavo-convex structure 36 also has a pattern shape below the resolution limit of electron beam lithography. Therefore, for example, it is extremely difficult to forge a planar view shape obtained by optically identifying the uneven structure 36 included in the individual authentication structure 31 manufactured as in the present embodiment. The produced individual authentication structure 31 has excellent clone resistance. Individual recognition can be performed by recognizing and recognizing such a planar view shape of the concavo-convex structure 36. Individual authentication can also be performed by recognizing and recognizing the three-dimensional shape and dimensions of the concavo-convex structure 36.

In the third embodiment as described above, the resin layer 35 having the concavo-convex structure 36 is formed on the substrate 31 by the imprint method using the mold 21 having the concavo-convex structure 8 to form the individual authentication structure 31. Since the concavo-convex structure 36 exhibits clone resistance that is difficult to forge, it is possible to manufacture a structure for individual authentication that is a fine artificial object having clone resistance.
Moreover, in this embodiment, after forming the resin layer 35 provided with the uneven structure 36 on the one surface 32a of the base material 32 by the imprint method using the mold 21, as shown in FIG. The base material 32 may be etched using the resin layer 35 as a mask to produce the individual authentication structure 31 ′ having the concavo-convex structure 37 on the base material 32. As described above, the concavo-convex structure 36 is a complicated shape reflecting the concavo-convex structure 8 of the mold 21, and a pattern shape below the resolution limit of the electron beam lithography can exist, and thus the base material 32. It is extremely difficult to forge the concavo-convex structure 37 formed by etching. Accordingly, the individual authentication structure 31 ′ produced by such imprint lithography has excellent clone resistance.
In the present embodiment, the manufactured individual authentication structures 31 and 31 'are diced into a chip having a desired size, for example, a chip having a size of 2 μm square to 100 μm square, and other objects requiring individual authentication. An individual authentication structure that can be incorporated into an object may be manufactured.

In addition, the resin layer 35 can be provided with a concavo-convex structure serving as an alignment mark during individual authentication together with the concavo-convex structure 36, and the substrate 32 can serve as an alignment mark during individual authentication together with the concavo-convex structure 37. An uneven structure can be provided. Such a mark for alignment may be provided on the individual authentication structure having the chip size.
The individual authentication structure 31 manufactured as described above includes a base material 32 and a resin layer 35 positioned on one surface 32a of the base material 32. The resin layer 35 has an uneven structure 36. However, the bottom position of the concave portion and the top position of the convex portion of the concave-convex structure 36 in the thickness direction of the resin layer 35 are not constant, and the concave-convex structure 36 has a concave portion and / or convex portion having a width of 20 nm or less. . The individual authentication structure 31 ′ manufactured as described above includes a base material 32 and a concavo-convex structure 37 positioned on one surface 32 a of the base material 32. The bottom position of the concave portion of the concavo-convex structure 37 and the top position of the convex portion are not constant, and the concavo-convex structure 37 has a concave portion and / or a convex portion having a width of 20 nm or less. Such individual authentication structures 31 and 31 'include, for example, a contour shape in plan view of the concavo-convex structures 36 and 37, a three-dimensional shape in cross-sectional view of the concavo-convex structures 36 and 37, a height and a depth of the concavo-convex structures 36 and 37. Individual authentication can be performed using the information.
Each above-mentioned embodiment of the present invention is an illustration, and the present invention is not limited to these embodiments.

Next, the present invention will be described in more detail with reference to examples.
[Example 1]
A quartz substrate (6 inches × 6 inches × 0.25 inches thick) was prepared as a substrate, and a chromium thin film (thickness of about 20 nm) was formed on the quartz substrate by sputtering.
Next, a negative electron beam sensitive resist was prepared as follows. That is, 12.4 g (0.1 mol) of 3-methoxyphenol was dissolved in 200 mL of ethanol in a 300 mL three-necked flask under a nitrogen atmosphere. While this was cooled in an ice bath, 10.6 g (0.1 mol) of benzaldehyde was added, and then 25 mL of concentrated hydrochloric acid was slowly added dropwise and reacted at 70 ° C. for 12 hours. After completion of the reaction, the reaction solution was poured into 500 mL of distilled water, and the resulting precipitate (yellow solid) was filtered and washed with distilled water until neutral. 100 parts by weight of the calixresorcinarene derivative thus obtained and 10 parts by weight of triphenylsulfonium nonafluorobutanesulfonate as an acid generator and 4,4-methylenebis [2,6- Bis (hydroxymethyl)] phenol 20 parts by weight and tri-n-octylamine 1 part by weight as an organic basic compound are dissolved in cyclopentanone (organic solvent), and the solid content concentration is 2.6 parts by weight. A negative electron beam sensitive resist was obtained.
This negative electron beam sensitive resist was applied onto the chromium thin film of the quartz substrate by spin coating, and pre-baked (100 ° C., 60 seconds) to form a resist layer having a thickness of 220 nm.

Next, 10 square areas of 200 μm × 200 μm are defined in this resist layer at 400 μm pitch, and pillars having a 100 nm side are arranged at 200 nm pitch by an electron beam lithography apparatus (pillar size = 100 nm, The pattern latent image was formed by performing electron beam drawing so that the pitch was 200 nm.
Next, after post-baking (110 ° C., 90 seconds), the resist layer is developed using a developer (TMAH: tetramethylammonium hydroxide), and then rinsed using a rinse solution. And dried.
Thus, a resist structure was formed in 10 regions on the quartz substrate defined as described above to obtain individual authentication structures (Sample 1-1 to Sample 1-10).
With respect to Sample 1-1 to Sample 1-10 produced in this way, a 5 μm × 5 μm region at the corner corresponding to the same position was measured using an SEM (scanning electron microscope: CD-SEM CG4000 manufactured by Hitachi HT Co., Ltd.). The results are shown in FIG.
As shown in FIG. 6, in Sample 1-1 to Sample 1-10, the resist pattern is deformed by the force acting from the rinsing liquid during the rinsing process, and various shapes are formed in almost the entire 200 μm × 200 μm square region. It was confirmed that the resist structure having the pattern aggregate was formed on the quartz substrate, and there was no resist structure having the same shape.

  As described above, a substrate and a resist structure composed of a plurality of resist patterns located on one surface of the substrate are provided, and an angle formed by each resist pattern and the substrate is less than 90 °. The inclination direction of the resist pattern and the interval between the resist patterns are not constant, and the pattern pattern of the three-dimensional structure is configured such that at least one state of leaning, overlapping and approaching each other exists in the resist pattern. It has been confirmed that an individual authentication structure having one or more aggregates in the resist structure can be used for individual identification by observing the contour shape of the resist structure in plan view.

[Example 2]
A silicon substrate (thickness: about 725 μm) having a diameter of 200 mm was prepared as a substrate. The silicon substrate may be subjected to a surface treatment as necessary, but in this example, the surface treatment was not performed in order to obtain an appropriate resist adhesion.
Next, a negative electron beam sensitive resist similar to that in Example 1 was applied to the above silicon substrate by spin coating, and pre-baked (100 ° C., 60 seconds) to form a resist layer having a thickness of 220 nm. Formed.
Next, 10 square regions of 200 μm × 200 μm were defined in this resist layer at 400 μm pitches to obtain Samples 2-1 to 2-9. Then, with respect to Sample 2-1 to Sample 2-9, electron beam drawing is performed using an electron beam drawing device with a combination of the pillar size and pitch set as follows to form nine types of pattern latent images. did.
Sample 2-1: pillar size = 200 nm, pitch = 400 nm
Sample 2-2: Pillar size = 180 nm, pitch = 360 nm
Sample 2-3: pillar size = 160 nm, pitch = 320 nm
Sample 2-4: pillar size = 140 nm, pitch = 280 nm
Sample 2-5: pillar size = 120 nm, pitch = 240 nm
Sample 2-6: Pillar size = 100 nm, pitch = 200 nm
Sample 2-7: Pillar size = 60 nm, pitch = 120 nm
Sample 2-8: pillar size = 50 nm, pitch = 100 nm
Sample 2-9: pillar size = 40 nm, pitch = 80 nm

Next, in the same manner as in Example 1, the resist layer was developed, and then rinsed and post-baked to form resist patterns (9 types of Sample 2-1 to Sample 2-9) on the silicon substrate. .
Next, using the resist pattern formed as described above as a mask, the silicon substrate was dry etched under the following dry etching conditions to form a concavo-convex structure.
(Dry etching conditions for silicon substrates)
・ Reactive gas: HBr
・ Gas flow rate: 900sccm
・ ICP power: 400W
・ RIE power: 150W
・ Pressure: 2.0Pa

With respect to the nine concavo-convex structures (Sample 2-1 to Sample 2-9) formed in this way, a 2 μm × 2 μm region at the corner corresponding to the same position was measured with an SEM (scanning electron microscope: CD manufactured by Hitachi HT Co., Ltd.). -SEM CG4000) and the results are shown in FIG.
As shown in FIG. 7, in a large pillar size and pitch larger than Sample 2-5 (pillar size = 120 nm, pitch = 240 nm), concave portions having the same shape in plan view on the silicon substrate after etching have a constant pitch. The concavo-convex structure having unique characteristics was not present. Therefore, in the resist pattern formed in this example, the resist pattern due to the force acting from the rinsing liquid at the time of development processing is used at a large pillar size and pitch larger than those of Sample 2-5 (pillar size = 120 nm, pitch = 240 nm). It was confirmed that no resist structure having pattern aggregates was formed on the silicon substrate.

  In Sample 2-6 (pillar size = 100 nm, pitch = 200 nm), the etched silicon substrate has a non-uniform concavo-convex structure in a part of a square region of 200 μm × 200 μm in plan view. It was. Therefore, in sample 2-6 (pillar size = 100 nm, pitch = 200 nm), a resist structure having a pattern aggregate due to deformation of a part of the resist pattern due to the force acting from the rinsing liquid during the development processing. It was confirmed that was formed. In Sample 2-6, it was confirmed that the resist pattern on the outer periphery of each square was likely to be deformed. Each square outer edge has a lower accumulated energy of electron beam at the time of drawing compared to the inner side, and as a result, the pattern size is reduced, and the resist pattern is deformed by the force acting from the rinsing liquid during the rinsing process. It is thought that this is likely to occur. In Example 1, it was possible to form resist structures having pattern aggregates of various shapes almost entirely in a 200 μm × 200 μm square region with the pillar size = 100 nm and the pitch = 200 nm. As described above, in Sample 2-6 (pillar size = 100 nm, pitch = 200 nm), the deformation of the resist pattern is limited to the outer edge portion of the square area of 200 μm × 200 μm. This is because there is a difference in the adhesion of the resist pattern due to the difference in quartz and silicon substrate materials.

Further, in Sample 2-7 (pillar size = 60 nm, pitch = 120 nm) and Sample 2-8 (pillar size = 50 nm, pitch = 100 nm), unevenness having a non-identical shape in plan view is formed on the etched silicon substrate. The structure was present almost over the entire square area of 200 μm × 200 μm. For this reason, deformation occurs in almost the entire area of the resist pattern due to the force acting from the rinsing liquid during the development process, and the resist structure having the pattern aggregate is formed in almost the entire square area of 200 μm × 200 μm. Was confirmed.
However, in sample 2-9 (pillar size = 40 nm, pitch = 80 nm), most of the resist pattern was washed away by the force acting from the rinsing solution during the development process, and it was impossible to form a resist structure. It was.

[Example 3]
A resist layer having a thickness of 220 nm was formed on the same silicon substrate as in Example 2 in the same manner as in Example 2.
Next, 10 square regions of 200 μm × 200 μm are defined in this resist layer at 400 μm pitches, and each region is formed with the same pattern setting as Sample 2-8 of Example 2 (pillar size = 50 nm, pitch = 100 nm). On the other hand, a pattern latent image was formed by performing electron beam drawing with an electron beam drawing apparatus.
Next, in the same manner as in Example 1, the resist layer was subjected to development processing, and then rinsed and post-baked. As a result, resist structures were formed in 10 square areas on the silicon substrate.
Next, using the resist structure formed as described above as a mask, the silicon substrate is dry etched under the same dry etching conditions as in Example 2 to form a concavo-convex structure to form a structure for individual authentication (Samples 3-1 to 3-1 Sample 3-10) was obtained.

With respect to Samples 3-1 to 3-10 produced in this way, a 2 μm × 2 μm region at the corner that hits the same position was measured using an SEM (scanning electron microscope: CD-SEM CG4000 manufactured by Hitachi HT Ltd.). The results are shown in FIG.
As shown in FIG. 8, in Samples 3-1 to 3-10, the resist pattern is deformed by the force acting from the rinsing liquid during the rinsing process, and the resist structures having pattern aggregates of various shapes are silicon. It was confirmed that the etched silicon substrate formed on the substrate and using such a resist structure as a mask has a non-uniform concavo-convex structure over almost the entire 200 μm × 200 μm square region.
In addition, five micro areas of 0.45 μm × 0.45 μm are selected from the 200 μm × 200 μm square area of the sample 3-1 to be measurement parts 1 to 5, and SEM ( The planar view shape and depth shape of the concavo-convex structure were observed using a scanning electron microscope: CD-SEM CG4000 manufactured by Hitachi HT Co., and the results are shown in FIGS. In each of FIGS. 9 to 13, a region surrounded by □ in (A) is a micro region of 0.45 μm × 0.45 μm, and (B) is an enlargement of this micro region.

As shown in FIGS. 9 to 13, in the plan view shape of the concavo-convex structure (the portion that appears black in the figure is a concave portion), there is a pattern interval that is below the resolution limit of electron beam lithography (for example, 20 nm or less). It was confirmed. It was also confirmed that the depth shape at each measurement site (curve indicating the depth at the chain line site in the horizontal direction in each figure) was complicated and the contours were completely different.
From the above, the substrate and the concavo-convex structure located on one surface of the substrate, the bottom position of the concave portion of the concavo-convex structure in the thickness direction of the base, the top position of the convex portion are not constant, The concavo-convex structure having a concave portion and / or a convex portion with a width of 20 nm or less can be used for individual identification by magnifying and observing the contour shape of the concavo-convex structure in plan view.

  The present invention can be applied to various uses for performing individual authentication using features unique to artifacts.

DESCRIPTION OF SYMBOLS 1,1 ', 31,31' ... Individual authentication structure 2 ... Base | substrate 3 ... Resist structure 5 ... Resist pattern 6 ... Pattern aggregate 8, 36, 37 ... Uneven structure 11 ... Resist layer 21 ... Mold 32 ... Base Material

Claims (5)

In the manufacturing method of the structure for individual authentication using an artifact,
Applying a chemical radiation sensitive resist on the substrate to form a resist layer;
Irradiating a desired portion of the resist layer with actinic radiation to form a latent image of the resist pattern; and
A step of developing the resist layer to form a resist pattern,
An external force is applied to at least a part of the resist pattern to cause at least one kind of deformation such as tilt, collapse, and slip in an arbitrary direction in an arbitrary degree, and at least one of leaning, overlapping, and approaching patterns separated from each other. A method for producing a structure for individual authentication, comprising: forming a resist structure having at least one three-dimensional pattern aggregate in a seeded state on the substrate.   As the external force, at least one of surface tension of the processing liquid in the rinsing process after the development process, electrostatic force generated by charging by charged particle beam irradiation, fluid pressure by fluid ejection, and vibration pressure by ultrasonic vibration is used. The manufacturing method of the structure for individual authentication of Claim 1 characterized by the above-mentioned.   3. The individual authentication according to claim 1, further comprising: forming a concavo-convex structure by etching the substrate using the resist structure as a mask after forming the resist structure on the substrate. Method for manufacturing a structural member.   The personal authentication according to claim 3, further comprising an imprinting step of forming a resin layer having a concavo-convex structure on a substrate using the substrate as a mold after the step of forming the concavo-convex structure. Manufacturing method of structure.   5. The method for manufacturing an individual authentication structure according to claim 4, wherein, in the imprint process, the uneven structure is formed by etching the base material using the resin layer as a mask.

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