JP2019080019A - Mold for imprint, pattern forming method using the same, and pattern forming apparatus - Google Patents

Abstract

To provide a mold for an imprint and the like capable of continuously forming a fine pattern in an area larger than an area of a pattern formed in the mold by aligning the fine pattern having a line width that is not resolved by visible light with high accuracy while making joints and alignment marks invisible visually in a patterned transfer substrate.SOLUTION: A mold for an imprint includes a first pattern including a plurality of first protrusions and a plurality of first recesses and a second pattern including a plurality of second protrusions and a plurality of second recesses, and when the wavelength included in an alignment light is λand the refractive index in the wavelength λof the material constituting the mold is n, a numerical value twice the depth Dof the second recess becomes an odd multiple of the numerical value dR represented by d=λ/{2(n-1)}.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an imprint mold used for manufacturing a semiconductor, an optical member, a MEMS member, a bio-related member, etc., a pattern forming method using the mold, and a pattern forming apparatus.

  Conventionally, as a method of forming a fine pattern, a photolithography method using a photomask is well known, and by using this photolithography method, for example, formation of a fine pattern required for a semiconductor device is performed. . However, to form a fine pattern by this photolithography method, an expensive exposure apparatus (called a stepper or a scanner) is required. Therefore, a nanoimprint method has been studied as one of the fine pattern forming techniques to replace the photolithography method.

  In the above nanoimprinting method, a mold for imprint (also referred to as a template, a stamper, or a mold) having a transfer pattern of fine concavo-convex shape formed on the surface is formed on a resin formed on a transfer substrate such as a semiconductor wafer After being brought into contact with the resin, the resin is cured to transfer the concavo-convex shape (more specifically, the concavo-convex inverted shape) of the pattern of the mold to the resin.

  In the nanoimprinting method, the resin is heated to a temperature above the glass transition point to soften it, the mold is pressed there to deform the resin, and the transferred substrate is cooled to cure the resin. There is a light imprint method to cure. For applications requiring high alignment accuracy, a light imprint method that is not affected by expansion or contraction due to heating is mainly used (for example, Patent Documents 1 and 2).

By using a nanoimprint method, it is possible to mass-produce fine patterns with an inexpensive apparatus. For this reason, utilization of this nanoimprinting method is studied as a method of forming a fine pattern in a substrate, a film, etc. of a large area.
However, the mold used for the nanoimprint method is mainly manufactured using the same material and equipment as the photomask for semiconductor devices used for the photolithography method, so the mold having a larger area than the ordinary photomask is used. Manufacturing is difficult in terms of technology and cost.

Here, as a method of imprinting on a large-area substrate, there is known a step-and-repeat method (also called step-and-flash method) in which a mold on the area smaller than the area of the substrate is used to move over the substrate and transfer sequentially. It is done.
However, in order to form a large-area pattern continuously on, for example, a display related member or the like by applying this method, in addition to highly accurate alignment, joints and alignments are formed on a patterned transfer substrate. It is necessary to devise to make marks and the like invisible.
Therefore, it has been proposed that an area in which the depth of the fine pattern is changed be provided in the area in which the fine pattern to be transferred is formed to be an alignment mark, and that alignment be performed using it (for example, Patent Document 3).

Japanese Patent Publication No. 2004-504718 JP 2002-93748 A JP 2007-230229 A JP, 2009-265290, A

  However, in Patent Document 3 described above, there is only a description of using an imaging system with high magnification as a method of alignment, and the magnification of a normal optical microscope is about 1000 times at maximum, so resolution with visible light is possible. In order to precisely connect fine patterns having an undetermined line width (for example, less than 1 μm), the precision was insufficient.

As a use which forms the fine pattern of the line | wire width which does not resolve with the above visible light over a large area, for example, there exists a polarizer for manufacturing the photo-alignment film for liquid crystal displays.
Here, the photo alignment film is an alignment film that expresses alignment control force by irradiation with linearly polarized light, and imparts alignment control force without performing rubbing processing with a cloth or the like like conventional alignment films. Since it can be done, attention has been paid in recent years because there is no problem that cloth or the like remains as foreign matter.
As a method of irradiating linearly polarized light for applying an alignment regulating force to such a light alignment film, a method of exposing through a polarizer is generally used. As a polarizer, one having a plurality of thin lines arranged in parallel on a transparent substrate is used (for example, Patent Document 4).

  The present invention has been made in view of the above-mentioned circumstances, and it is a fine pattern of a line width not resolved by visible light while making joints and alignment marks invisible visually on a patterned substrate to be transferred. Even for an imprint mold, a fine pattern can be continuously formed on an area larger than the area of the pattern formed on the mold with high precision alignment, and a pattern forming method using the mold And, the main object is to provide a patterning device.

That is, the invention according to claim 1 of the present invention is an imprint for forming a transfer pattern having a concavo-convex shape on a curable resin provided on the reflective film of a transferred substrate having a reflective film on the main surface. Mold for forming a first pattern including a plurality of first protrusions and a plurality of first recesses, a plurality of second protrusions and a plurality of second recesses, and an alignment mark And the first pattern and the second pattern have the same line width and pitch, and the first and second convex portions have the same maximum width and pitch. Included in the light used for alignment when using the second transfer pattern formed on the curable resin from the second pattern at the same height position on the surface as the alignment mark of the transfer substrate the wavelengths and lambda _R, wherein When the refractive index at the wavelength λ _R after curing of the curable resin is n _R , the numerical value twice the depth D ₂ of the second concave portion is
d _R = λ _R / {2 (n _R −1)}
The mold for imprinting is characterized in that it has a size that is an odd multiple of the numerical value d _R represented by

The invention according to claim 2 of the present invention is a pattern forming method for forming a transfer pattern of concavo-convex shape on a curable resin provided on the reflective film of a transferred substrate having a reflective film on the main surface. Using the mold for imprint according to claim 1 as the mold for imprint, bringing the mold for imprint into contact with the curable resin, and using the first pattern of the mold for imprint A first transfer pattern is formed on the curable resin, and a second transfer pattern is formed on the curable resin from a second pattern of the imprint mold, and then the imprint mold is A first step of releasing from a curable resin, a second step of changing the relative position between the imprint mold and the transfer substrate, and the curing A third step of aligning the position of the imprint mold with the transfer target substrate using the second transfer pattern formed on the resin as an alignment mark, and the alignment is performed in the third step The imprint mold is brought into contact with the curable resin at a relative position to form a first transfer pattern from the first pattern of the imprint mold to the curable resin, and for the imprint Forming a second transfer pattern from the second pattern of the mold to the curable resin, and thereafter releasing the mold for imprinting from the curable resin. in a third step, by using the alignment light having a wavelength lambda _R, the second irradiating the transfer pattern, the second transfer path from the reflected light And detecting the position of the over emissions, a pattern forming method.

  The invention according to claim 3 of the present invention is the pattern forming method according to claim 2, characterized in that the second step to the fourth step are repeated after the first step. is there.

  In the invention according to claim 4 of the present invention, the curable resin is an ultraviolet curable resin which is cured by ultraviolet light, and the light used for the alignment has a wavelength which is the ultraviolet light which cures the ultraviolet curable resin. It is the pattern formation method of Claim 2 or Claim 3 which is different light.

  The invention according to claim 5 of the present invention is the pattern forming method according to claim 4, wherein the wavelength of light used for the alignment is in the range of 360 nm to 830 nm.

The invention according to claim 6 of the present invention uses the mold for imprinting according to claim 1 as the mold for imprinting, and reflects light used for alignment on the main surface as the substrate to be transferred. Using a substrate to be transferred on which a reflective film is formed, the mold for imprinting is brought into contact with a curable resin provided on the reflective film of the substrate to be transferred, and a transfer pattern of concave and convex shapes on the curable resin A mold moving mechanism for moving the imprint mold, a transferred substrate moving mechanism for moving the transferred substrate, and a second transfer pattern formed on the curable resin. A detection mechanism that optically detects the position of the transfer substrate using the alignment mark, the mold moving mechanism, the transfer substrate moving mechanism, and the detection mechanism And a control for controlling mechanism, wherein the detection mechanism, a light including the wavelength lambda _R is irradiated to the second transfer pattern, and detecting the reflected light from the reflected light the detection, the control mechanism Acquiring the position of the second transfer pattern, and based on the acquired position information, the control mechanism operates the mold moving mechanism and the transfer substrate moving mechanism to obtain the imprint mold And the substrate to be transferred.

  Further, in the invention according to claim 7 of the present invention, the control mold may operate the mold moving mechanism and the transferred substrate moving mechanism to position the imprint mold at the aligned position. A first transfer pattern is formed on the curable resin from the first pattern of the imprint mold in contact with the curable resin, and the second pattern of the imprint mold has a second pattern. 7. The pattern forming apparatus according to claim 6, wherein a transfer pattern is formed on the curable resin.

  According to the present invention, it is possible to precisely align even a fine pattern having a line width which is not resolved by visible light, while making joints and alignment marks invisible on a patterned transfer substrate. The fine pattern can be continuously formed in an area larger than the area of the pattern formed in the mold.

The figure shown about an example of the mold concerning the present invention The figure shown about an example of the alignment mark of the mold concerning the present invention The figure explaining the alignment mark formed in curable resin on a substrate to be transferred using the mold concerning the present invention The figure which demonstrates the effect of the alignment mark formed in curable resin on a to-be-transferred substrate using the mold concerning this invention. Schematic process chart showing an example of a method of manufacturing a mold according to the present invention FIG. 5 is a schematic flowchart showing an example of a method for producing a mold according to the present invention following FIG. The figure shown about an example of the pattern formation method using the mold concerning the present invention The figure shown about an example of the pattern formation method using the mold concerning the present invention which follows on FIG. 7 The figure shown about the other example of the pattern formation method using the mold concerning the present invention The figure shown about the other example of the pattern formation method using the mold based on this invention following FIG. Schematic diagram showing the configuration of a pattern forming apparatus according to the present invention

  Hereinafter, a mold for imprinting according to the present invention, a pattern forming method using the mold, and a pattern forming apparatus will be described in detail with reference to the drawings.

<Mold for imprint>
First, an imprint mold according to the present invention will be described.
FIG. 1 is a view showing an example of a mold according to the present invention. More specifically, FIG. 1 shows a schematic plan view for explaining the configuration of the mold 1.

For example, as shown in FIG. 1, the mold 1 has a region in which the second pattern 3 is formed in the region in which the first pattern 2 is formed. More specifically, the mold 1 shown in FIG. 1 has four regions in which the second pattern 3 is formed in the vicinity of the four corners of the region in which the first pattern 2 is formed.
In the mold 1, each of the first pattern 2 and the second pattern 3 is a transfer pattern of a concavo-convex shape transferred to the curable resin on the transfer substrate. Furthermore, the second pattern 3 is also used as an alignment mark.

  As an example, the external dimensions of the mold 1 are 65 mm in length, 65 mm in width, and 0.25 inches in thickness (6.35 mm), and the area of the first pattern 2 including the area of the second pattern 3 corresponds to that of the mold 1 The central portion can be 20 mm × 20 mm in size. Further, the area of the second pattern 3 can be made to have a size of 20 μm × 20 μm in the vicinity of the four corners of the area of the first pattern 2 described above.

  The planar form of the area of the second pattern 3 is not limited to the square shown in FIG. 1 and may be any form such as a rectangle or a cross. Also, the arrangement position of the area of the second pattern 3 is not limited to the four corners shown in FIG.

FIG. 2 is a view showing an example of the alignment mark of the mold according to the present invention, and (a) is a schematic enlarged view of a region where the second pattern 3 of the mold 1 shown in FIG. (B) is a sectional view taken along the line A-A of (a).
In FIG. 2A, the dashed line indicating the area in which the second pattern 3 is formed is slightly larger than the area in which the second pattern 3 is formed in order to avoid the difficulty in determining the overlap due to duplication. It describes in the position which encloses an area.

For example, as shown in FIG. 2 (b), the first pattern 2 of the mold 1 is composed of a plurality of first projections 2T and a plurality of first recesses 2B, and a plurality of second patterns 3 are provided. And a plurality of second recesses 3B.
In FIG. 2, in order to avoid complication, the number of the first convex portions 2T constituting the first pattern 2 and the second convex portions 3T constituting the second pattern 3 is two. Although an example of about three is shown, in actuality, both the first pattern 2 and the second pattern 3 are composed of a larger number of convex portions.

As shown in FIG. 2A, the first pattern 2 and the second pattern 3 are line-and-space patterns in which the line width (W) and the pitch (P) are equal to each other.
More specifically, the first convex portion 2T constituting the first pattern 2 and the second convex portion 3T constituting the second pattern 3 have the same line width (W) and pitch (P), and are flat As viewed, the second pattern 3 constitutes a line-and-space pattern that is continuous with the first pattern 2.
In other words, a partial region of the first pattern 2 is the second pattern 3.
Note that the above “line width and pitch (P) are equal to each other” includes a range that is treated as “equal” in the accuracy required for the mold 1.

Further, as shown in FIG. 2B, the height positions of the outermost surfaces of the first convex portion 2T and the second convex portion 3T are equal to each other. Here, “the height positions are equal to each other” includes a height range which is treated as “equal” in the accuracy required for the mold 1.
However, the depth of the first recess 2B (D ₁₎ and the depth of the second recess 3B (D ₂₎ are different. That is, it can be said that the difference between the first pattern 2 and the second pattern 3 is that the depth is different.
In the present invention, by setting the depth D2 of the second concave portion 3B to a specific size, the alignment mark formed on the curable resin on the transfer substrate using the mold 1 is resolved by visible light. Even if it is comprised from the fine pattern of the line | wire width which does not image, it is possible to align with high precision.

FIG. 3 is an alignment mark formed on a curable resin on a transferred substrate (more specifically, on the reflective film of the transferred substrate having a reflective film on the main surface) using the mold according to the present invention It is a figure explaining.
Here, FIG. 3A is a diagram for better understanding the relationship between the concavo-convex pattern of the mold 1 and the concavo-convex pattern formed on the curable resin 60 on the transfer substrate 50, and FIG. (B) is a figure for demonstrating the structure of the uneven | corrugated pattern formed in the curable resin 60 on the to-be-transferred substrate 50. FIG.

As shown in FIGS. 3A and 3B, by forming a pattern using the mold 1, the curable resin 60 on the transferred substrate 50 has the concavo-convex shape of the first pattern 2 of the mold 1 (more Specifically, the first transfer pattern 61 to which the concavo-convex reversal shape is transferred and the second transfer pattern 62 to which the concavo-convex shape of the second pattern 3 of the mold 1 (more specifically, the concavo-convex reversal shape) is transferred It is formed. The second transfer pattern 62 is also used as an alignment mark of the transfer substrate.
Then, as shown in FIG. 3B, the difference between the height position of the outermost surface of the first transfer pattern convex portion 61T and the height position of the outermost surface of the second transfer pattern convex portion 62T is | D ₁ -D ₂ | become.

  The transfer substrate 50 has a configuration in which the reflective film 52 is formed on the main surface of the substrate 51. The reflective film 52 acts as a film that reflects alignment light. Furthermore, the reflective film 52 may function as an etching mask in a pattern formation method described later.

Here, FIG. 3 shows a configuration example in which the reflective film 52 is provided in contact with the substrate 51, and the curable resin 60 is provided in contact with the reflective film 52. The invention is not limited to this configuration example.
For example, another layer may be provided between the substrate 51 and the reflective film 52, and another layer may be provided between the reflective film 52 and the curable resin 60.

  In the present invention, “upper” in the description “on the substrate to be transferred (more specifically, on the reflection film on the substrate to be transferred having the reflection film on the main surface)” means the substrate to be transferred: It represents the side on which the reflective film is provided.

  FIG. 4 is an alignment mark formed on a curable resin on a substrate to be transferred (more specifically, on the reflective film of the substrate to be transferred having a reflective film on the main surface) using the mold according to the present invention It is a figure explaining an effect. Here, FIG. 4A is a view showing an optical path difference of alignment light, and FIG. 4B is a view showing an intensity of alignment light (reflected light) to be detected.

As shown in FIG. 4A, alignment light 71 incident on the concave portion of the second transfer pattern 62 (that is, the second transfer pattern concave portion 62B shown in FIG. 3B) is reflected by the reflection film 52. And the optical path difference (path difference) of the alignment light 72 that is incident on the convex portion of the second transfer pattern 62 (that is, the second transfer pattern convex portion 62T shown in FIG. 3B) and is reflected by the reflection film 52 a multiplied by the refractive index of the medium), the wavelength of the alignment light 71 and 72 as a lambda _R, a refractive index at a wavelength lambda _R after curing of the curable resin 60 and n _R, around the mold 1 of the atmosphere When the refractive index is n _A
n _R x 2 x D _2- n _A x 2 x D ₂
It becomes.
In addition, since the numerical value of n _A can usually be set to 1, the above equation is
2 × D ₂ × (n _R −1)
It can be expressed.

Therefore, when the wavelength of the alignment light 71 and 72 is λ _R and the refractive index at the wavelength λ _R after curing of the curable resin 60 is n _R , the above-mentioned numerical value twice D ₂ is
d _R = λ _R / {2 (n _R −1)}
By designing so that the value is an odd multiple of the numerical value d _R represented by, the relationship between the reflected light of the alignment light 71 and the reflected light of the alignment light 72 can be made to be a relationship in which the phases are inverted from each other. Thus, the reflected light of the alignment light 71 and the reflected light of the alignment light 72 act to cancel each other.

  Therefore, as shown in FIG. 4B, the alignment light in the area in which the second transfer pattern 62 is formed as compared to the intensity of the reflected light of the alignment light in the area in which the first transfer pattern 61 is formed. The intensity of the reflected light can be reduced.

Therefore, as shown in FIG. 4B, by detecting the intensity distribution of the alignment light (more specifically, the reflected light of the alignment light), the distance LR can be obtained. The center position of the alignment mark of the substrate 50 (more specifically, the center position of the second transfer pattern 62 of the curable resin 60 formed on the transfer target substrate 50) can be obtained with high accuracy.
Then, by obtaining the center position of the alignment mark with high accuracy, it is possible to obtain the position information of the transfer substrate 50 with high accuracy. From the position information of the transfer substrate 50, the mold 1 and the transfer substrate 50 are accurately positioned. It can be fitted.

  Here, in the example shown in FIG. 4B, in the waveform showing the intensity distribution of the detected alignment light (more specifically, the reflected light of the alignment light), the maximum value [Max] of the light intensity and the light The distance between two points (P1, P2) which is an intermediate value [Med = (Max + Min) / 2] with the minimum value [Min] of intensity is defined as LR.

  The above shows an example of how to determine the LR, and the present invention is not limited to this example. In the present invention, any method that can acquire the center position of the alignment mark with good reproducibility from the intensity distribution of the detected alignment light (more specifically, the reflected light of the alignment light) can be used.

For example, a waveform (for example, FIG. 4B) indicating the intensity distribution of the detected alignment light (more specifically, the reflected light of the alignment light) is processed by a differentiation circuit, and the differentiation as shown in FIG. A waveform may be obtained and the distance between the two vertices may be defined as LR.
In addition, the method of acquiring a dimension from the waveform of a reflected signal which is used for the former dimension measuring machine can also be used suitably.

As described above, by using the imprint mold according to the present invention, positional information of the transfer substrate can be obtained with high accuracy, and the mold and the transfer substrate can be accurately positioned based on the positional information of the transfer substrate. It can be fitted.
Therefore, by using the mold for imprinting according to the present invention, a fine pattern having a line width which is not resolved by visible light while making joints and alignment marks invisible on a pattern-formed transferred substrate. Even if there is, the fine pattern can be continuously formed in an area larger than the area of the pattern formed in the mold, with high precision alignment.

  Furthermore, since the fine pattern can be continuously formed in an area larger than the area of the pattern formed in the mold, the area of the mold may be small relative to the area of the substrate to be transferred, equipment for manufacturing the mold, or the like There is also an economic effect that space saving and a reduction in the amount of capital investment can be expected without requiring large equipment for equipment etc. using molds.

Further, in the present invention, since the reflected light is used, the length for forming the optical path difference can be halved as compared to the case where the transmitted light is used. More specifically, the value of D ₂ can be reduced to 1⁄2 as compared to the case of using transmitted light.
This has the effect of making it easier to form fine patterns (the first pattern 2 and the second pattern 3) in the mold 1. Further, also when forming a pattern (the first transfer pattern 61 and the second transfer pattern 62) on the curable resin 60 using the mold 1, the resin pattern having a height higher than the width is torn off at the time of release. It is more effective to prevent such problems.

  Each material will be described below.

(Material that constitutes mold 1)
The material which comprises the mold 1 can be used for an optical imprint method, and can transmit the exposure light at the time of imprint.
In general, ultraviolet light having a wavelength of 200 nm to 400 nm, particularly 300 nm to 380 nm, and more typically 365 nm (so-called i-line) is used as the exposure light.

Any material that can be applied to the light imprinting method can be used as a material for forming the mold 1, and for example, synthetic quartz, glass, calcium fluoride (CaF ₂ ), magnesium fluoride (MgF ₂ ), and Examples thereof include transparent materials such as acrylic glass, and laminated structures of these transparent materials. In particular, synthetic quartz is suitable as a material for the mold 1 because it has high rigidity, a low thermal expansion coefficient, and good transmittance in the range of 300 nm to 380 nm, which is a commonly used wavelength.

(Material of substrate 51)
When the substrate 51 is used for an optical member such as a polarizer, examples of the material constituting the substrate 51 include synthetic quartz, glass, calcium fluoride (CaF ₂ ), magnesium fluoride (MgF ₂ ), and acrylic glass. Transparent materials and laminated structures of these transparent materials can be mentioned. The substrate 51 may be made of resin.
In addition, when used for other applications, the substrate 51 may be opaque to visible light. For example, the substrate 51 may be made of a material containing silicon (Si) or various metals.

(Material of the reflective film 52)
As a material for forming the reflective film 52, any material can be used as long as it acts as a film that reflects the alignment lights 71 and 72.
Here, it is preferable to use, as the alignment lights 71 and 72, light of a wavelength different from the exposure light so as not to cure the curable resin 60. For the alignment lights 71 and 72, for example, visible light having a wavelength of 400 nm or more and 830 nm or less (in particular, around 633 nm) can be used. Alternatively, mercury lamp e-line (546 nm) or sodium D-line (589 nm) can be used.
In addition, the reflective film 52 may function as an etching mask in a pattern formation method described later.

As a material which comprises the reflection film 52, the material containing chromium (Cr), a tantalum (Ta), ruthenium (Ru) etc. can be mentioned, for example. The reflective film 52 may have a single layer structure or a multilayer structure made of a plurality of materials.
Here, if the film thickness of the reflective film 52 is too thin, the effect of reflection is reduced. On the other hand, if the film thickness is too thick, it will not be suitable for fine processing in the later etching processing and the like.
When chromium (Cr) is used as the material forming the reflective film 52, its film thickness can be, for example, in the range of 10 nm to 100 nm.

(Curable resin 60)
As the curable resin 60, any photocurable resin applicable to the photo-imprinting method can be used, and an ultraviolet curable resin cured by ultraviolet light can be suitably used.
For example, PAK-01 (made by Toyo Gosei Kogyo Co., Ltd.), NIP-K (made by Zen Photonics), TSR-820 (made by Teijin Instruments Co., Ltd.) etc. can be mentioned.
The refractive index of the curable resin 60 as described above for light in the wavelength range of 400 nm to 830 nm is generally about 1.5 to 1.7.

<Method of manufacturing mold for imprint>
Next, a method of manufacturing an imprinting mold according to the present invention will be described.
5 and 6 are schematic process drawings showing an example of the method for producing a mold according to the present invention.
In order to manufacture the mold 1 according to the manufacturing method shown in FIGS. 5 and 6, first, the base material 11 is prepared, and the hard mask layer 12 is formed on the main surface (FIG. 5A).

  The substrate 11 is made of the same material as that of the mold 1 and can be used for the light imprinting method, and can transmit exposure light at the time of imprinting. For example, synthetic quartz is suitable as a material used for the substrate 11.

  The hard mask layer 12 is processed into a predetermined pattern in a later step, and acts as an etching mask when the first pattern 2 and the second pattern 3 of the mold 1 are formed. The material constituting the hard mask layer 12 can function as the above-mentioned etching mask. Examples of the hard mask layer 12 include metal films containing chromium (Cr), molybdenum (Mo), and the like, and oxide films and nitride films thereof.

Next, a first resin pattern 13 is formed on the hard mask layer 12 (FIG. 5 (b)).
The first resin pattern 13 is for forming the first pattern 2 and the second pattern 3 of the mold 1 (more specifically, for forming the hard mask pattern 12P). It can be formed by coating an electron beam resist, drawing an electron beam, and developing. Alternatively, the curable resin may be formed into a predetermined shape by using a nanoimprint method.

  Next, the hard mask layer 12 exposed from the first resin pattern 13 is etched to form a hard mask pattern 12P (FIG. 5C). For example, when a metal film containing chromium (Cr) is used for the hard mask layer 12, dry etching using a mixed gas of oxygen and chlorine can be used for this etching.

Next, the base 11 exposed from the first resin pattern 13 and the hard mask pattern 12P is etched to a predetermined depth (D ₂ ) (FIG. 5 (d)), and then the first resin pattern 13 is removed (FIG. 6 (e)).
The predetermined depth (D ₂ ) corresponds to the depth D ₂ of the second recess 3 B of the second pattern 3 of the mold 1. When the substrate 11 is made of synthetic quartz, dry etching using a fluorine-based gas can be used for this etching. In addition, for example, ashing with oxygen gas can be used to remove the first resin pattern 13.

In the example shown in FIGS. 5 and 6, the base material 11 is etched while leaving the first resin pattern 13 (FIG. 5 (d)), and then the first resin pattern 13 is removed. However, in the present invention, the present invention is not limited thereto, and the first resin pattern 13 is first removed, and then the hard mask pattern 12P is used as an etching mask to form the hard mask pattern 12P. The exposed substrate 11 may be etched to a predetermined depth (D ₂ ).

Next, the second resin pattern 14 is formed in a predetermined region (FIG. 6 (f)).
The predetermined area corresponds to an area where the second pattern 3 of the mold 1 is formed. The second resin pattern 14 can be formed, for example, by applying an electron beam resist, drawing an electron beam, and developing.

Next, the base 11 exposed from the second resin pattern 14 and the hard mask pattern 12P is etched to a predetermined depth (D ₁ -D ₂ ) (FIG. 6 (g)).
D ₁ of the this predetermined depth is equivalent to the depth D ₁ of the first of the first recess 2B of the pattern 2 of the mold 1. When the substrate 11 is made of synthetic quartz, dry etching using a fluorine-based gas can be used for this etching.

Thereafter, the second resin pattern 14 and the hard mask pattern 12P are removed to obtain a mold 1 having the first pattern 2 and the second pattern 3 (FIG. 6 (h)).
For removing the second resin pattern 14, for example, ashing with oxygen gas can be used. When a metal film containing chromium (Cr) is used for the hard mask pattern 12P, dry etching using a mixed gas of oxygen and chlorine can be used for the removal.

<Pattern formation method>
Next, a method of forming a pattern using an imprint mold according to the present invention, in particular, a method of continuously forming a fine pattern in an area larger than the area of the pattern formed on the mold will be described.

7 and 8 are views showing an example of a pattern forming method using a mold according to the present invention.
The concavo-convex transfer pattern (the first pattern 2 and the second pattern 3) formed on the mold 1 by this method is formed on the large-area transfer substrate 50 (more specifically, the main pattern of the transfer substrate 50). In order to continuously transfer and form the curable resin 60 on the reflective film 52 formed on the surface), first (first) imprinting is performed in the same manner as in the conventional nanoimprinting method.

  More specifically, as shown in FIG. 7A, the surface of the mold 1 on which the pattern is formed and the curable resin 60 on the transfer substrate 50 are disposed opposite to each other, and are brought into contact with each other, as shown in FIG. And harden the curable resin 60 in contact with the mold 1 to form the first transfer pattern 61 from the first pattern 2 of the mold 1 to the curable resin 60 and the second pattern of the mold 1. The pattern 3 to the second transfer pattern 62 are formed on the curable resin 60, and then the mold 1 is released from the curable resin 60 on the transfer substrate 50 (first step).

  As a method of curing the curable resin 60, a method of using an ultraviolet curable resin as the curable resin 60 and irradiating the region where the pattern is to be formed with ultraviolet light from the back surface side of the mold 1 (the surface on which the pattern is not formed) Can be mentioned.

  In the first (first) imprint, since no seam occurs in the first place, in principle, high-precision alignment is not necessary. Therefore, for example, the degree of alignment may be based on the outer shape of the transfer substrate 50.

  Next, as shown in FIG. 7B, the relative position between the mold 1 and the transfer substrate 50 is changed (second step), and the transfer substrate 50 is formed by the previous imprint (first imprint). The position of the mold 1 and the transferred substrate 50 are aligned by alignment using the second transfer pattern 62 formed on the upper curable resin 60 (third step).

In the alignment step (third step), for the location of the transfer substrate 50 side, as described with reference to FIG. 4, using the alignment light having a wavelength lambda _R, the second transfer pattern 62 The position information of the transfer target substrate 50 (more specifically, the position information of the curable resin 60 formed on the transfer target substrate 50) can be obtained by detecting the position of.

On the other hand, the position information of the mold 1 obtained separately may be used for the position on the mold 1 side.
The position information (position information of the second transfer pattern 62 etc.) of the curable resin 60 formed on the transfer substrate 50 is an accurate position until the first (first) imprint described above is performed. Although no information can be obtained, there is no such limitation on the position on the mold 1 side. For example, when the mold 1 is attached to the pattern forming apparatus used in this pattern forming method, the mold 1 in the pattern forming apparatus It is sufficient if the relative position of can be grasped.

For example, when the mold 1 is attached to the pattern forming apparatus used in this pattern forming method, a method of grasping the relative position of the mold 1 in the pattern forming apparatus by detecting the position of the second pattern 3 of the mold 1 is disclosed. It may be adopted.
Alternatively, a method of grasping the relative position of the mold 1 in the pattern forming apparatus using marks or the like separately provided on the mold 1 may be adopted.

Next, a second imprint is performed at the aligned relative positions described above, as in the conventional nanoimprint method.
More specifically, as shown in FIG. 7C, the surface on which the pattern of the mold 1 is formed is brought into contact with the curable resin 60 on the transfer substrate 50 at the above-mentioned aligned relative position. In this state, the curable resin 60 in contact with the mold 1 is cured to form the first transfer pattern 61 from the first pattern 2 of the mold 1 to the curable resin 60 and the mold 1 has The second pattern 3 to the second transfer pattern 62 are formed on the curable resin 60, and then the mold 1 is released from the curable resin 60 on the transfer substrate 50 (fourth step).

  Between the transfer pattern formed in the second imprint and the transfer pattern formed in the first (first) imprint, in principle, a seam will be present, as described above Since alignment enables the mold 1 and the transfer substrate 50 (more specifically, the curable resin 60 formed on the transfer substrate 50) to be aligned with high accuracy, the seam is not visible visually be able to.

  Next, as shown in FIG. 7D, the relative position between the mold 1 and the transfer substrate 50 is changed again (second step), and transfer is performed by the previous imprint (second imprint). The mold 1 and the transferred substrate 50 (more specifically, the curable resin formed on the transferred substrate 50) by alignment using the second transfer pattern 62 formed on the curable resin 60 on the substrate 50 60) Align with 60) (third step).

Next, a third imprint is performed at the above aligned relative positions in the same manner as in the conventional nanoimprint method.
More specifically, as shown in FIG. 8 (e), the surface on which the pattern of the mold 1 is formed is brought into contact with the curable resin 60 on the transfer substrate 50 at the above-mentioned aligned relative position. In this state, the curable resin 60 in contact with the mold 1 is cured to form the first transfer pattern 61 from the first pattern 2 of the mold 1 to the curable resin 60 and the mold 1 has The second pattern 3 to the second transfer pattern 62 are formed on the curable resin 60, and then the mold 1 is released from the curable resin 60 on the transfer substrate 50 (fourth step).

  Thereafter, the same steps are repeated, that is, the step of changing the relative position of the mold 1 and the transfer substrate 50 (second step), and the step of aligning the position of the mold 1 and the transfer substrate 50 (third step) Step (f), imprinting step (fourth step) is repeated to cure the pattern of the mold 1 on the large-area transfer substrate 50 as shown in FIG. Can be continuously transferred and formed on the base resin 60.

  Here, as shown in FIG. 8F, not only the first transfer pattern 61 but also the second transfer pattern 62 is included in the transfer pattern formed on the curable resin 60. That is, in this state, although the seams in the imprint can be made invisible visually, the alignment mark (second transfer pattern 62) can be identified depending on the size of the area. It will

Therefore, the thin film portion of the curable resin 60 (a portion corresponding to the concave portion 61B of the first transfer pattern 61 and the concave portion 62B of the second transfer pattern 62) is removed by etching, and then, FIG. As shown in FIG. 8E, the reflective film 52 exposed from the curable resin 60 is removed by etching, and then, as shown in FIG. 8H, the substrate 51 exposed from the curable resin 60 and the reflective film 52. Is etched to a predetermined depth.
For example, when the reflective film 52 is made of chromium (Cr), dry etching using a mixed gas of oxygen and chlorine can be used for this etching.
When the transfer substrate 50 is made of glass, dry etching using a fluorine-based gas can be used for this etching.

  After that, the curable resin 60 and the reflective film 52 are removed, and as shown in FIG. 8I, it is possible to obtain a structure 90 in which a fine pattern of concavo-convex shape is continuously formed. As an example, the area of the structure 90 in which the fine pattern is continuously formed can be A3 size (297 mm × 420 mm).

In the example shown in FIG. 8H, the substrate 51 is etched to a predetermined depth by using the curable resin 60 and the reflective film 52 as an etching mask, but in the present invention, other methods are used. For example, first, the curable resin 60 may be removed, and the substrate 51 may be etched to a predetermined depth using only the etched reflective film 52 as an etching mask.
Thereafter, the reflective film 52 is removed, and similarly, a structure 90 shown in FIG. 8I can be obtained.

Here, as described with reference to FIG. 2, the first pattern 2 and the second pattern 3 of the mold 1 are line and space patterns in which the line width (W) and the pitch (P) are equal to each other, In plan view, the second pattern 3 constitutes a line and space pattern continuous with the first pattern 2.
Therefore, the fine pattern formed in this structure 90 is a line and space pattern in which the line width, pitch and depth are equal to one another over the entire area, and in this structure 90, the alignment marks (more specifically, The trace of the second transfer pattern 62 can not be identified.

  That is, by using the pattern forming method of the present invention, even a fine pattern having a line width which is not resolved by visible light while making joints and alignment marks invisible on a pattern-formed transferred substrate The fine pattern can be continuously formed in an area larger than the area of the pattern formed in the mold with high precision alignment.

  Furthermore, since the fine pattern can be continuously formed in an area larger than the area of the pattern formed in the mold, the area of the mold may be small relative to the area of the substrate to be transferred, equipment for manufacturing the mold, or the like There is also an economic effect that space saving and a reduction in the amount of capital investment can be expected without requiring large equipment for equipment etc. using molds.

  In the pattern formation method shown in FIGS. 7 and 8, as shown in FIG. 7C, the alignment mark (second pattern 3) of the mold 1 and the curable resin 60 by the previous imprinting are used. Although an example in which the formed second transfer pattern 62 is imprinted so as to overlap is shown, the present invention is not limited to this, and in a pattern-formed transfer substrate, seams and alignment marks are not visible visually It is sufficient if the alignment can be performed with high accuracy while imprinting.

  For example, positional information of the mold 1 and positional information of the transfer substrate 50 (more specifically, positional information of the curable resin 60 on the reflective film 52 formed on the main surface of the transfer substrate 50) are individually acquired. Then, the mold 1 and the transfer substrate 50 are positioned and arranged based on each position information, and as shown in FIGS. 9 and 10, the transfer pattern formed on the curable resin 60 in the previous imprinting is overlapped. Instead of the pattern located on the outermost part of the transfer pattern formed on the curable resin 60 by the previous imprint, continuously (in other words, the line and space pattern in which the line width and the pitch are continuously equal over the entire area) ) May be patterned.

<Pattern forming device>
Next, a pattern forming apparatus according to the present invention will be described.
FIG. 11 is a schematic view showing the configuration of a pattern forming apparatus according to the present invention.

  As shown in FIG. 11, the pattern forming apparatus 100 according to the present invention forms the mold 1 on the transfer substrate 50 (more specifically, on the reflective film 52 formed on the main surface of the transfer substrate 50). It is a pattern forming apparatus for forming a transfer pattern of concavo-convex shape on the curable resin 60 by bringing the curable resin 60 into contact, the mold moving mechanism 101 for moving the mold 1, and the object for moving the transfer substrate 50 A transfer substrate moving mechanism 103 and a detection mechanism 104 for optically detecting the position of the transfer substrate 50 using the second transfer pattern 62 formed on the curable resin 60 on the transfer substrate 50 as an alignment mark. And a control mechanism 105 that controls the mold moving mechanism 101, the transfer substrate moving mechanism 103, and the detection mechanism 104.

The detection mechanism 104 irradiates the light including the wavelength λ _R to the second transfer pattern 62 formed on the curable resin 60, detects the reflected light, and the control mechanism 105 detects the reflected light. The control mechanism 105 operates the mold moving mechanism 101 and the transfer substrate moving mechanism 103 based on the acquired position information to obtain the mold 1 and the transfer substrate 50 based on the acquired position information. Align the.

  Then, the mold 1 is brought into contact with the curable resin 60 on the transfer substrate 50 at a position where the control mechanism 105 operates and aligns the mold transfer mechanism 101 and the transfer substrate moving mechanism 103 to perform molding. The first transfer pattern 61 to the first transfer pattern 61 of 1 are formed on the curable resin 60, and the second transfer pattern 62 to the second transfer pattern 62 of the mold 1 are formed on the curable resin 60.

  Here, the pattern forming apparatus 100 shown in FIG. 11 includes the exposure mechanism 102, and the exposure mechanism 102 is also controlled by the control mechanism 105. The exposure mechanism 102 irradiates ultraviolet light to cure the curable resin 60 patterned by the mold 1.

  By using this pattern forming apparatus 100 in the above pattern forming method of the present invention, a line width which is not resolved by visible light while making joints and alignment marks invisible on a pattern-formed transferred substrate Even in the case of the fine pattern of the present invention, the fine pattern can be continuously formed in an area larger than the area of the pattern formed in the mold by aligning with high accuracy.

  Furthermore, since the fine pattern can be continuously formed in an area larger than the area of the pattern formed in the mold, the area of the mold may be smaller than the area of the transfer substrate, for example, the mold moving mechanism 101 or exposure There is also an economic effect that space saving and reduction in capital investment can be expected without requiring large facilities in the mechanism 102.

  The pattern forming apparatus according to the present invention uses the imprint mold according to the present invention and the substrate on which the reflective film is formed, and the second transfer pattern formed on the curable resin on the transfer substrate. Is used as an alignment mark to optically detect the position of a substrate to be transferred, and to form a pattern continuously (a line-and-space pattern in which the line width and pitch are continuously equal throughout the substrate). The other configuration can be the same as that of the conventional imprint apparatus.

  As mentioned above, although each embodiment was described about the mold for imprint concerning the present invention, the pattern formation method using the mold, and the pattern formation device, the present invention is not limited to the above-mentioned embodiment. . The above embodiment is an exemplification and has substantially the same configuration as the technical idea described in the claims of the present invention, and exhibits the same function and effect as the present invention in any case. It is included in the technical scope of

DESCRIPTION OF SYMBOLS 1 mold 2 1st pattern 2T 1st convex part 2B 1st concave part 3 2nd pattern 3T 2nd convex part 3B 2nd concave part 11 base material 12 hard mask layer 12P hard mask pattern 13 1st resin Pattern 14 Second resin pattern 50 Substrate to be transferred 51 Substrate 52 Reflective film 60 Curing resin 61 First transfer pattern 61 T First transfer pattern convex portion 61 B First transfer pattern concave portion 62 Second transfer pattern 62 T Second Transfer pattern convex portion 62 B Second transfer pattern concave portion 71, 72 Alignment light 81 First etching gas 82 Second etching gas 90 Structure 100 Pattern forming device 101 Mold moving mechanism 102 Exposure mechanism 103 Transfer substrate moving mechanism 104 Detection mechanism 105 Control mechanism

Claims (7)

It is an imprint mold for forming a transfer pattern having a concavo-convex shape on a curable resin provided on the reflective film of a transferred substrate having a reflective film on the main surface,
A first pattern comprising a plurality of first protrusions and a plurality of first recesses;
A plurality of second protrusions and a plurality of second recesses, and having a second pattern used as an alignment mark,
The first pattern and the second pattern have equal line widths and pitches.
The height positions of the outermost surfaces of the first convex portion and the second convex portion are equal to each other,
A second transfer pattern formed on the cured resin from the second pattern, the when using as an alignment mark of the transferred substrate, a wavelength included in the light used for alignment and lambda _R,
When the refractive index at the wavelength λ _R after curing of the curable resin is n _R ,
A value twice the depth D ₂ of the second recess is
d _R = λ _R / {2 (n _R −1)}
A mold for imprinting, having a size that is an odd multiple of the numerical value d _R represented by A pattern forming method for forming a transfer pattern having an uneven shape on a curable resin provided on a reflective film of a transferred substrate having a reflective film on the main surface,
The imprinting mold according to claim 1 is used as the imprinting mold,
The imprint mold is brought into contact with the curable resin to form a first transfer pattern from the first pattern of the imprint mold to the curable resin, and the imprint mold has A first step of forming a second transfer pattern from the second pattern to the curable resin, and thereafter releasing the imprint mold from the curable resin;
A second step of changing a relative position between the imprint mold and the transfer substrate;
A third step of aligning the position of the imprint mold and the transfer substrate using the second transfer pattern formed on the curable resin as an alignment mark;
The imprint mold is brought into contact with the curable resin at the relative position aligned in the third step, and the first transfer pattern is cured from the first pattern of the imprint mold. Forming the resin from the second pattern of the imprint mold to the second transfer pattern on the curable resin and thereafter releasing the imprint mold from the curable resin; 4 processes,
Have
In the third step, light including a wavelength λ _R is used for alignment to irradiate the second transfer pattern, and the position of the second transfer pattern is detected from the reflected light. , Pattern formation method.   The pattern formation method according to claim 2, wherein the second step to the fourth step are repeated after the first step. The curable resin is an ultraviolet curable resin which is cured by ultraviolet light,
The pattern formation method according to claim 2 or 3, wherein the light used for the alignment is light having a wavelength different from that of the ultraviolet light for curing the ultraviolet curable resin.   The pattern formation method according to claim 4, wherein a wavelength of light used for the alignment is in a range of 360 nm to 830 nm. The imprinting mold according to claim 1 is used as the imprinting mold, and the transferred substrate is used as the transferred substrate, on the main surface of which the reflecting film for reflecting the light used for alignment is formed. A pattern forming apparatus for forming a transfer pattern having a concavo-convex shape on the curable resin by bringing an imprint mold into contact with a curable resin provided on the reflective film of the transfer substrate,
A mold moving mechanism for moving the imprint mold;
A transfer substrate moving mechanism for moving the transfer substrate;
A detection mechanism that optically detects the position of the transfer substrate using the second transfer pattern formed on the curable resin as an alignment mark;
The mold moving mechanism, the transfer target substrate moving mechanism, and a control mechanism that controls the detection mechanism;
The detection mechanism irradiates the light including the wavelength λ _R to the second transfer pattern, and detects the reflected light;
The control mechanism acquires the position of the second transfer pattern from the detected reflected light,
The control mechanism operates the mold moving mechanism and the transferred substrate moving mechanism based on the acquired positional information to align the imprint mold with the transferred substrate. A pattern forming apparatus characterized by:   The control mechanism operates the mold moving mechanism and the transfer substrate moving mechanism to bring the imprint mold into contact with the curable resin at the aligned position, thereby the imprint mold And forming a first transfer pattern from the first pattern on the curable resin to the first pattern, and forming a second transfer pattern from the second pattern on the imprint mold on the curable resin. The patterning device according to claim 6, wherein

Images