JP5332161B2 - Imprint mold, imprint mold manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imprint mold having a multi-step uneven pattern, the imprint mold being characterized in that the imprint mold and a resin pattern are excellently released from each other and an optical imprint method free of a decrease in releasing property even when repeatedly implemented can be implemented. <P>SOLUTION: The imprint mold where the uneven pattern with a plurality of steps is formed needs to be inverted in phase difference at a corner portion of each step. In this case, a phase difference correction pattern also needs to have a plurality of steps for correction by only itself. The number of steps of the phase difference correction pattern can be suppressed by providing the phase difference correction pattern and a phase shift layer, so the imprint mold where the uneven pattern with the plurality of steps is formed can be manufactured more suitably. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an imprint mold and an imprint mold manufacturing method.

  An imprint mold in which a specific fine three-dimensional structure pattern (for example, a multi-step shape) is formed on a substrate (for example, glass, resin, metal, silicon, etc.) is expected to be used in a wide range of fields. Has been. For example, semiconductor devices, optical elements, wiring circuits, recording devices (such as hard disks and DVDs), medical testing chips (such as DNA analysis applications), display panels, and microchannels can be used.

  In recent years, there has been an increasing demand for finer patterns and structures with a larger number of steps in imprint molds.

  For example, in the semiconductor field, it has been proposed to use a multi-stage imprint mold in forming a dual damascene structure in which a specific fine three-dimensional structure pattern is formed (see Non-Patent Document 1).

  In the imprint method, a mold called an imprint mold (sometimes referred to as a template) in which a pattern corresponding to a negative / positive reversal image of a pattern to be finally transferred is formed on a resin, and the resin is in that state. The pattern is transferred by curing. At this time, a photoimprint method is known in which a photocurable resin is cured by irradiating exposure light (see Patent Document 1).

  In the imprint method, the peelability between the imprint mold and the resin pattern generated on the substrate is extremely important. This will be described with reference to FIG. In general, the curing of the resin causes a resin shrinkage and generates a stress between the imprint mold and the resin pattern. For this reason, after the resin is cured (FIG. 1 (a)), in the step of separating the imprint mold and the resin pattern, the resin moves to the imprint mold side (FIG. 1 (b)), and a part of the pattern is It is known that the resin pattern remains on the imprint mold side (FIG. 1C) and the resin pattern has a defect.

  At this time, it has been reported that the defect of the resin pattern in peeling frequently occurs at the corner part which is the boundary between the convex pattern part and the concave pattern part of the concave / convex pattern where stress is concentrated at the time of peeling (FIG. 1D). (See Non-Patent Document 2).

On the other hand, as a method for improving releasability, a method of applying a fluoropolymer having a small surface energy to the surface of an imprint mold as a release agent has been proposed (see Patent Document 2).
JP 2000-194142 A JP 2002-283354 A Proc. Of SPIE., Vol.5992, pp.786-794 (2005) Y.Hirai, et al. J. Vac. Sci. Technol., Vol. 21, pp. 6 (2003)

  However, even if the release agent is applied to the surface, if the release agent is repeatedly subjected to the imprint method, the release agent is gradually peeled off from the surface of the imprint mold, and the peelability between the imprint mold and the resin is lowered. In particular, in a multi-stage imprint mold, when a release agent on a concavo-convex pattern having a plurality of steps is applied, the release agent on the convex portion in the concavo-convex pattern becomes thin, or excessive release agent remains in the concave portion. Therefore, flat coating cannot be performed, and it is difficult to improve the uniform peelability.

  Therefore, the present invention has been made to solve the above-mentioned problems, and even an imprint mold having a multi-step uneven pattern has excellent releasability between the imprint mold and the resin pattern, and is repeatedly imprinted. It is an object of the present invention to provide an imprint mold capable of performing an optical imprint method in which the peelability does not decrease even when the method is performed.

  The present invention according to claim 1 is the imprint mold used in the optical imprint method for forming a fine uneven pattern, wherein the substrate, the uneven pattern provided on the substrate, and the uneven pattern are formed. A phase difference correction pattern provided on a substrate surface opposite to the substrate surface, and a phase displacement layer provided on a substrate surface opposite to the substrate surface on which the uneven pattern is formed, the uneven pattern comprising: An imprint mold characterized by being an uneven pattern having a plurality of steps.

  The present invention according to claim 2 is the imprint mold according to claim 1, wherein the phase displacement layer is at least one selected from the group consisting of molybdenum, tungsten, tantalum, silicon, oxygen, and nitrogen. An imprint mold characterized by being a material containing the above elements.

  A third aspect of the present invention is the imprint mold according to the first or second aspect, wherein the phase displacement layer is a multilayered phase displacement layer. is there.

  According to a fourth aspect of the present invention, in the imprint mold manufacturing method, a step of laminating at least one phase displacement layer having a refractive index different from that of the substrate on the substrate surface, and a multi-step uneven pattern on the substrate are provided. And a step of forming a phase difference correction pattern on the substrate surface opposite to the substrate surface on which the concave / convex pattern is formed, and a step of patterning the phase displacement layer. It is a print mold manufacturing method.

The imprint mold of the present invention is characterized in that a phase difference correction pattern and a phase displacement layer are provided on a substrate surface opposite to a substrate surface on which a concavo-convex pattern having a plurality of steps is formed.
According to the configuration of the present invention, due to the phase difference correction pattern and the phase displacement layer, the difference between the cross-sectional dimension of the convex pattern portion and the cross-sectional dimension of the concave pattern portion is a half wavelength of the coherent exposure light or an odd number of half wavelengths. It can be adjusted to be equal to the optical path length corresponding to double. For this reason, by controlling the exposure intensity, it is possible to selectively reduce the degree of curing of the photo-curing resin at a specific site, to reduce the shear force due to fixation and shrinkage stress due to curing, The occurrence of defects can be suppressed. At this time, since the optical path length can be adjusted by the phase difference correction pattern and the phase displacement layer, the transfer pattern can be determined without depending on the wavelength of the coherent exposure light.
In particular, in the case of an imprint mold in which a concavo-convex pattern having a plurality of steps is formed, the phase difference needs to be reversed at the corners of each step. At this time, if correction is performed only with the phase difference correction pattern, the phase difference correction pattern also needs to have a plurality of steps. In the present invention, by providing the phase difference correction pattern and the phase displacement layer, it is possible to suppress the number of steps of the phase difference correction pattern, and more preferably, an imprint in which an uneven pattern having a plurality of steps is formed. A mold can be manufactured.

  Hereinafter, the imprint mold of the present invention will be described.

  By having a phase displacement layer having a refractive index different from the refractive index of the material used for the imprint mold, between the contact surface between the imprint mold and the transfer substrate and the exposure light source that emits coherent exposure light. The degree of curing of the resin on the transfer substrate can be controlled by the phase shift layer portion, thickness, refractive index, and the like. For this reason, in the process of peeling the imprint mold and the resin pattern, the portion where the defect of the resin pattern occurs can be selectively uncured, and the occurrence of the defect of the transfer pattern can be suppressed.

FIG. 2A illustrates the principle of the present invention, and shows a case where the imprint mold is irradiated with coherent exposure light.
The wavefront A of the coherent light 200 incident on the mold 100 in FIGS. 2A and 2A is an uneven pattern of the mold 100 indicated by 410 and 420 parts of the phase displacement layer 90 formed on a part of the light transmitting material 70. The distance A including 60 and the distance B are respectively passed. If the difference distance C between the cross-sectional dimension (distance A) including the concavo-convex pattern 60 parts and the substrate cross-sectional dimension (distance B) is set to an optical path length corresponding to a half wavelength of the coherent exposure light or an odd multiple of the half wavelength, the wavefront B Then, the light is phase-reversed relative to the adjacent 410 and 420, and as a result, the light is emitted from the mold 100 as the wavefront B ′ as the phase-reversed light.

  The light intensity will be described with reference to FIGS. In the light transmitted through 410 and 420, the light intensity is the same (here, for convenience of explanation, the transmittance attenuation of the phase shift layer 90 itself is ignored). Since the phase is inverted, the light amplitudes (intensities) of 410 and 420 on the wavefront B are separated for convenience, and the vertical axis is relatively opposed to the top and bottom of the drawing. At this time, due to the diffraction effect by the corners A and B, a tail-like diffracted light 430 is generated. In the diffracted light 430, the light intensity is the same, and in the combined light intensity 440 shown in FIGS. 2 (A) and 2 (c), the light energy intensities at the corners A and B are close to zero because they are canceled by the inverted phase. . This zero light energy portion occurs selectively at the wavefront B position where phase inversion occurs.

具体例として、例えば、下記の条件で、必要な位相変位層９０の膜厚である距離Ｃ＝Ｔは、「数１」より、６４．３ｎｍとなる。
λ：１９３ｎｍ（ＡｒＦエキシマレーザーの波長）
ｎ_ｈｔ：２．５（位相変位層９０の屈折率）
ｎ_ａｉｒ：１（大気の屈折率） The distance C necessary for the phase inversion shown in FIG. 2A will be described with reference to FIG. As described above, the phase inversion mechanism may be an odd multiple of one half of the wavelength (λ) or one half of the wavelength (λ) in the optical path length. The wavelength of the light source is λ (nm), the refractive index of the phase shift layer 90 is n _ht , the difference between the sectional dimension of the convex pattern part and the sectional dimension of the concave pattern part is T (distance C), and the refractive index of the atmosphere is n _air . In this case, the relational expression is expressed by “Equation 1”.

As a specific example, for example, the distance C = T, which is the required film thickness of the phase shift layer 90, is 64.3 nm from “Equation 1” under the following conditions.
λ: 193 nm (wavelength of ArF excimer laser)
n _ht : 2.5 (refractive index of the phase displacement layer 90)
n _air : 1 (atmospheric refractive index)

FIG. 3A illustrates the principle of the present invention, and is a diagram in which an example of an imprint mold is irradiated with coherent exposure light.
The wavefront A of the coherent light 200 incident on the mold 100 in FIGS. 3A and 3A passes through the distance A and the distance B by the concave / convex pattern 60 of the mold 100 indicated by 415 and 425 parts, respectively. If the difference distance C between the cross-sectional dimension (distance A) of the convex pattern portion and the cross-sectional dimension (distance B) of the concavo-convex pattern 60 is set to an optical path length corresponding to a half wavelength of the coherent exposure light or an odd multiple of the half wavelength, the wavefront In B, the light is emitted as a phase-reversed light at adjacent 415 and 425.

  The light intensity will be described with reference to FIGS. 3A, 3B and 3A, 3C. In the light transmitted through 415 and 425, the light intensity is the same. (Here, the transmittance attenuation of the mold 100 itself is ignored for convenience of explanation). Since the phase is inverted, the light amplitudes (intensities) of 415 and 425 in the wavefront B are separated for convenience and the vertical axis is relatively opposed to the top and bottom of the drawing. At this time, due to the diffraction effect by the corners C and D, a tail-like diffracted light 430 is generated. In the diffracted light 430, the light intensity is the same, and in the combined light intensity 440 shown in FIGS. 3 (A) and 3 (c), the light energy intensity at the corners C and D is close to zero because they are canceled by the inverted phase. . This zero light energy portion occurs selectively at the wavefront B position where phase inversion occurs.

具体例として、例えば、下記の条件で、必要な距離Ｃ（＝Ｔ）は、「数１」より、１９３ｎｍとなる。
λ：１９３ｎｍ（ＡｒＦエキシマレーザーの波長）
ｎ_ｑ：１．５（インプリントモールド材質の屈折率の屈折率）
ｎ_ａｉｒ：１（大気の屈折率） The distance C necessary for the phase inversion shown in FIG. As described above, the phase inversion mechanism may be an odd multiple of one half of the wavelength (λ) or one half of the wavelength (λ) in the optical path length. When the wavelength of the light source is λ (nm), the refractive index of the imprint mold material is n _q , the difference between the cross-sectional dimension of the convex pattern part and the cross-sectional dimension of the concave pattern part is T, and the refractive index of the atmosphere is n _air Is expressed by “Equation 2” as described above.

As a specific example, for example, the necessary distance C (= T) is 193 nm from “Equation 1” under the following conditions.
λ: 193 nm (wavelength of ArF excimer laser)
n _q : 1.5 (refractive index of refractive index of imprint mold material)
n _air : 1 (atmospheric refractive index)

図３（Ｃ）の場合、距離Ｔと屈折率ｎが各々ｔ_１とｎ_ｑ、ｔ_２とｎ_ｈｔに分割されるため、

上記「数４」式を満たす関係のとき、凸パターン部と凹パターン部の境界において、露光光は１８０°位相が反転する。
具体例として、例えば、下記の条件で、ｔ_１＝１００ｎｍとした場合に必要なｔ_２は、「数４」より、ｔ_２について解くと３１ｎｍとなる。
λ：１９３ｎｍ（ＡｒＦエキシマレーザーの波長）
ｎ_ｈｔ：２．５
ｎ_ｑ：１．５（インプリントモールド材質の屈折率の屈折率）
ｎ_ａｉｒ：１（大気の屈折率）
ｔ_１：１００ｎｍ Here, in FIG. 3A, the distance C may be divided into t ₁ + t ₂ as shown in FIG. 3B.
Further, with respect to the distance t2, the equivalent optical path length can be replaced with the phase displacement layer 90 as shown in FIG. 3C from the principle described with reference to FIG.
The t ₂ necessary for the phase inversion shown in FIG. As described above, the phase inversion mechanism may be an odd multiple of one half of the wavelength (λ) or one half of the wavelength (λ) in the optical path length. The wavelength of the light source is λ (nm), the refractive index of the imprint mold material / phase shift layer is nq, the difference between the cross-sectional dimension of the nht convex pattern part and the cross-sectional dimension of the concave pattern part is T (t ₁ , t ₂ ), When the refractive index is n _air , the basic relational expression is expressed in the same manner as the above “Equation 2”.
First, Equation 2 is transformed into Equation 3.

In the case of FIG. 3C, the distance T and the refractive index n are divided into t ₁ and n _q , t ₂ and n _ht , respectively.

In the relationship satisfying the above-mentioned “Equation 4”, the phase of the exposure light is inverted by 180 ° at the boundary between the convex pattern portion and the concave pattern portion.
As a specific example, for example, t ₂ required when t ₁ = 100 nm under the following conditions is 31 nm when solved for t ₂ from “Equation 4”.
λ: 193 nm (wavelength of ArF excimer laser)
n _ht : 2.5
n _q : 1.5 (refractive index of refractive index of imprint mold material)
n _air : 1 (atmospheric refractive index)
t ₁ : 100 nm

上記「数５」式を満たす関係のとき、凸パターン部と凹パターン部の境界において、露光光は１８０°位相が反転する。
具体例として、例えば、下記の条件で、ｔ_１＝５０ｎｍとした場合に必要なｔ_２は、「数５」より、ｔ_２について解くと１７３ｎｍとなる。
λ：１９３ｎｍ（ＡｒＦエキシマレーザーの波長）
ｎ_ｒ：１．７
ｎ_ｑ：１．５（インプリントモールド材質の屈折率の屈折率）
ｎ_ａｉｒ：１（大気の屈折率）
ｔ_１：５０ｎｍ Further, the case of FIG. 3B will be described. In an actual mold, the portion of the distance t ₁ is filled with the photo-curing resin, and the refractive index is not the air described above, but the refractive index of the resin as shown in FIG. A description will be given of t2 necessary for phase inversion shown in FIG. As described above, the phase inversion mechanism may be an odd multiple of one half of the wavelength (λ) or one half of the wavelength (λ) in the optical path length. The wavelength of the light source is λ (nm), the refractive index of the imprint mold material / phase shift layer is n _q , the difference between the cross sectional dimension of the n _ht convex pattern part and the cross sectional dimension of the concave pattern part is T (t ₁ , t ₂ ), When the refractive index of the atmosphere is n _air , the basic relational expression is expressed by “Equation 5” where the refractive index of the term of t ₁ in “Equation 4” is n _r .

In the relationship satisfying the above-mentioned “Expression 5”, the phase of the exposure light is inverted by 180 ° at the boundary between the convex pattern portion and the concave pattern portion.
As a specific example, for example, t ₂ required when t ₁ = 50 nm under the following conditions is 173 nm when solved for t ₂ from “Equation 5”.
λ: 193 nm (wavelength of ArF excimer laser)
_nr : 1.7
n _q : 1.5 (refractive index of refractive index of imprint mold material)
n _air : 1 (atmospheric refractive index)
t ₁ : 50 nm

  In the imprint mold of the present invention, a fine concavo-convex pattern is formed on a substrate, and at least one phase displacement layer is laminated on the substrate surface opposite to the substrate surface on which the concavo-convex pattern is formed. It is preferable that the patterning is performed so as to face the uneven pattern. By making the concave and convex patterns on the front and back face each other, in particular, the resin at the part corresponding to the corner part that is the boundary between the convex pattern part and the concave pattern part, where defects are known to occur frequently, may be uncured. I can do it. For this reason, the defect at the time of peeling of the corner part which is a boundary of a convex pattern part and a concave pattern part can be suppressed.

  The phase displacement layer is required to be different from the refractive index of the material used for the imprint mold, and can be appropriately selected according to the coherent exposure light used in the optical imprint method.

  The phase displacement layer is preferably a material containing at least one element selected from the group consisting of molybdenum, tungsten, tantalum, silicon, oxygen, and nitrogen. By using the material, it is possible to preferably control the film thickness, the refractive index, and the like. Thereby, arbitrary mold dimensions can be realized.

Further, as shown in FIG. 3 (C), t ₁ Yorazu the size of the uneven pattern desired as a mold, the thickness t ₂ of the phase shift layer _90, by controlling the refractive index n _2, the over only t ₁ The insufficient optical path length can be made to correspond to the half wavelength of the coherent exposure light at the thickness t ₂ of the phase displacement layer 90 or an odd multiple of the half wavelength, and the phase can be inverted by 180 degrees. This principle has also been explained with reference to FIG.

The principle of the imprint mold having the phase displacement layer will be described with reference to FIG. In FIG. 4, the dimension of a desired pattern is t ₁ and the thickness of the phase shift layer 90 is t ₂ .
In the case of FIG. 4, in Equation 1, T corresponds to dividing into _two of t ₁ and t ₂ , and T and n are divided into separate t ₁ and n _r , t ₂ and n _ht . Further, when the refractive index of the light propagation medium that causes phase inversion is at the wavefront A, it is generally in the atmosphere (refractive index n _air = 1), and at the wavefront B, it is in the photocurable resin (refractive index n _r ). .

上記「数６」式を満たす関係のとき、凸パターン部と凹パターン部の境界において、露光光は１８０°位相が反転する。

In the relationship satisfying the above-mentioned “Expression 6”, the phase of the exposure light is inverted by 180 ° at the boundary between the convex pattern portion and the concave pattern portion.

As a specific example, for example, the film thickness t of the phase displacement layer 90 (n ₂ ) necessary for a mold having a concavo-convex pattern of 100 nm on an imprint mold 100 (t ₁ , n _q ) made of quartz glass under the following conditions: ₂ is 51 nm from “Equation 6”.
λ: 193 nm (wavelength of ArF excimer laser)
n _q : 1.5 (refractive index of the quartz glass substrate 10)
t ₁ : 100 nm (dimension pattern dimension)
n _ht : 2.5 (refractive index of the phase change layer 90)
_nr : 1.7 (refractive index of photocuring resin)
n _air : 1 (atmospheric refractive index)

  At this time, the phase displacement layer 90 is a phase displacement layer having a transmittance with respect to the exposure light such that the exposure light that has passed through the phase displacement layer 90 does not have the light intensity necessary for curing the photocurable resin. Is preferred. The above case will be described with reference to FIG.

  When the transmittance of the phase shift layer 90 is reduced, the light intensity of 410 parts transmitted through the mold 100 has the distribution shown in FIG. 5A, and the light intensity is reduced compared to 420 parts. The combined light intensity is as shown in FIG. The photo-curable resin 120 is cured with the light intensity of the exposure light transmitted through 420 parts, and is transmitted through the phase shift layer 90 by using a photo-curable resin having a sensitivity that is not cured with the light intensity of the exposure light transmitted through 410 parts. The photo-curing resin at the site can be not selectively cured. Thereby, in the peeling of the transfer substrate and the mold, which will be described later, the sticking effect due to resin shrinkage due to curing is relieved at the dotted line portion E.

  As an example of the imprint mold of the present invention, FIG. 6 illustrates an imprint mold having a two-step uneven pattern that causes phase inversion twice. For convenience, the description in FIG. 2A to FIG. 5 will be cited, and description will be made using the same symbols. In FIG. 6, 415 and 425 parts are the mold 100 and have the same structure as FIG. In 100 parts of the mold, the phase inversion occurs at the wavefront B as described with reference to FIGS. Further, regarding the second-stage uneven pattern, 420 and 410 parts are the mold 200, and the phase inversion appears on the wavefront C as described with reference to FIG.

Further, FIG. 7A shows a case where the transmittance of the phase shift layer 90 described in FIG. 5 in FIG. 6 is controlled and the curing sensitivity of the photo-curing resin 120 is controlled.
As an example in FIG. 7B in FIG. 7B, M3 and M4 dimensions required for phase inversion when the desired two-stage mold dimensions M1 = 100 nm and M2 = 50 nm are calculated. Region A in FIG. 7B is FIG. 3D, and region B is the same as FIG. M3 is 173 nm and M4 is 51 nm. Although the thickness M _sub of the substrate itself, phase inversion is an effect caused by the difference in refractive index. For this reason, transmitting the thickness of the substrate itself is an intermediate medium whose refractive index is unchanged and does not contribute to phase inversion. Therefore, the thickness M _sub of the substrate itself may be an arbitrary dimension.
λ: 193 nm (wavelength of ArF excimer laser)
n _air : 1 (atmospheric refractive index)
n _q : 1.5 (refractive index of the quartz glass substrate 10)
n _ht : 2.5 (refractive index of the phase change layer 90)
_nr : 1.7 (refractive index of the photo-curing resin 120)
M1: First stage mold size = 100 nm
M2: second stage mold dimension = 50 nm

  Hereinafter, the imprint mold manufacturing method of the present invention will be described.

<Process for forming concave / convex pattern on substrate>
First, an uneven pattern is formed on the substrate.
The substrate is required to be a material that transmits exposure light used in the photoimprint method. Examples of a material that transmits general exposure light include quartz glass.
As a method of forming the concavo-convex pattern, it may be formed using a known fine processing technique as appropriate according to the desired size and shape of the concavo-convex pattern. For example, it may be formed by appropriately combining a photolithography method, a dry etching method, a wet etching method, a laser processing method, a micromachining method, and the like.

<Step of laminating phase shift layer>
Next, a phase displacement layer is laminated on the substrate surface opposite to the substrate surface on which the concavo-convex pattern is formed.
This phase displacement layer is required to be different from the refractive index of the material used for the imprint mold, and can be appropriately selected according to the wavelength of the coherent exposure light used in the optical imprint method. Further, a plurality of layers may be laminated according to the optical path difference necessary for phase inversion.

  At this time, the phase displacement layer is a material containing at least one element selected from the group consisting of molybdenum, tungsten, tantalum, silicon, oxygen, and nitrogen (for example, molybdenum oxynitride silicide (MoSiOxNy)). Is preferred. By using the material, it is possible to preferably control the film thickness, the refractive index, and the like.

  As a method of laminating the phase shift layer, a known thin film forming method may be used as appropriate. For example, you may form using PVD method, CVD method, spin coat method, slit coat method, spray coat method, dip coat method, etc.

<Step of patterning phase shift layer>
Next, the phase displacement layer is patterned so as to face the uneven pattern.

  As the step of patterning the phase shift layer, a known patterning method can be used as appropriate. For example, the pattern may be formed using a lithography technique, an etching technique, or the like.

<Step of forming phase difference correction pattern>
Next, a phase difference correction pattern is formed on the substrate surface outside the patterned phase displacement layer. A structural pattern may be formed in the same manner as the above-described <Process for forming an uneven pattern on a substrate>.

  Hereinafter, the optical imprint method using the imprint mold of the present invention will be described.

  In the optical imprint method using the imprint mold of the present invention, it is preferable that the exposure light is coherent light and an imprint mold having a phase displacement layer is used. The exposure light that has passed through the phase displacement layer and the exposure light that has not passed through the phase displacement layer have different phases, and the light intensity of the exposure light is close to zero at a location where the phase is 180 ° different. Thereby, the corner part which is a boundary of the convex pattern part and concave pattern part of an uneven | corrugated pattern can be made into an unhardened site | part. Furthermore, in the phase displacement layer, an imprint mold that is a phase displacement layer having a transmittance for exposure light to such an extent that the exposure light that has passed through the phase displacement layer does not have the light intensity necessary for curing the photo-curing resin. By using it, the part of the remaining film unnecessary for the transfer pattern can be uncured. This means that the amount of exposure can be controlled, and the degree of curing of the photocurable resin at a specific site can be selectively lowered. Therefore, it is possible to reduce the shearing force caused by the fixing and shrinkage stress due to the curing of the resin, which improves the releasability and consequently suppresses the occurrence of defects in the transfer pattern.

<Example 1>
Hereinafter, an example of implementation of the imprint mold manufacturing method of this invention is shown. As a matter of course, the imprint mold manufacturing method of the present invention is not limited to the following examples, and may be other manufacturing methods that can be inferred in each step.

  First, a sacrificial film 20 made of chromium (Cr), which is a conductive metal, was formed on a quartz glass substrate 10 serving as a mold material by a sputtering method (FIG. 8A). The sacrificial film 20 is for preventing charge-up of charged electrons in electron beam lithography in the next process, and is preferably conductive.

  Next, an electron beam reaction type resist 30 was applied to the sacrificial film 20, and a resist pattern 40 was formed on the sacrificial film 20 by exposure and development processes using a lithography method (FIG. 8B).

  Next, using the resist pattern 40 as a mask, a mask pattern 50 was formed on the sacrificial film 20 by a dry etching method using a reactive etching (RIE) method using a mixed gas of chlorine and oxygen (FIG. 8C).

Next, a concavo-convex pattern 60 was formed on the quartz glass substrate 10 by a dry etching method using a reactive etching (RIE) method using a C ₂ F ₆ and oxygen mixed gas (FIG. 8D).

  Next, the resist pattern 40 was removed by ashing by oxygen plasma treatment (FIG. 8 (e)).

  Next, the resist 30 was applied again to form the resist pattern 40 on the mold pattern 60 (FIG. 8F).

  Next, the concavo-convex pattern 65 was formed by a dry etching method using a reactive etching (RIE) method using C2F6 and an oxygen mixed gas (FIG. 8G).

  Next, the resist pattern 40 and the mask pattern 50 (sacrificial film 20) were removed, and mold patterns 60 and 61 were obtained on the quartz glass substrate 10 (FIG. 8H).

  Next, a light-transmitting material 70 was formed on the substrate surface opposite to the substrate surface on which the concavo-convex pattern was formed by sputtering, and a resist 30 was applied to obtain a resist pattern 40 (FIG. 8 ( i)).

  Next, by using the resist pattern 40 as a mask, the light transmitting material 70 is etched by a dry etching method using a corrosive gas, thereby forming a phase displacement layer 90 (mold pattern 62) corresponding to the mold pattern 60 (FIG. 8 (FIG. 8 ( j).

  Next, the resist pattern 40 was once removed by ashing by oxygen plasma treatment, and the resist 30 was applied again to obtain a resist pattern 40. (FIG. 3 (A) (k)).

Next, a mold pattern 63 was formed using the resist pattern 40 as a mask by a dry etching method based on a reactive etching (RIE) method using C ₂ F ₆ and an oxygen mixed gas (FIG. 8L).

Next, the resist pattern 40 was removed by ashing by oxygen plasma treatment.
From the above, the mold 300 which is an example of the imprint mold of the present invention could be manufactured.

<Example 2>
Hereinafter, an example of the optical imprint method using the imprint mold of the present invention will be described in detail with reference to FIG.

  First, the transfer substrate 110 was arranged at a position opposed to the mold 300 manufactured in Example 1 at a certain interval, and the photocurable resin 120 was applied on the transfer substrate 110 (FIG. 9A).

  Next, the mold 300 is bonded to the transfer substrate 110 coated with the photocurable resin 120 in the air or in a reduced pressure atmosphere, and irradiated with coherent light 200 having a predetermined wavelength for resin curing, and the photocurable resin 120 is cured. (FIG. 9B).

  Next, the mold 300 and the transfer substrate 110 were pulled back in the direction opposite to the bonding direction, and a transfer pattern 130 made of the photocurable resin 120 was obtained on the transfer substrate 110 (FIG. 9C).

  Next, the uncured portion 140 was cured by being irradiated with the coherent light 200 or the light 210 having a wavelength for curing the photocurable resin (FIG. 9D).

Next, the residual film 150 unnecessary for the desired transfer pattern 130 was removed by ashing using oxygen plasma or the like (FIG. 9E).
As described above, the transfer pattern 130 can be formed on the transfer substrate 110.

  The imprint mold of the present invention is expected to be used in a wide range of fields where fine pattern formation is desired. For example, semiconductor devices, optical components such as optical waveguides and diffraction gratings, recording devices such as hard disks and DVDs, life It is expected to be used in the manufacturing process of products such as biochips used for DNA analysis and the like in the science field, diffusion plates and light guide plates used for image / video displays in the display field and the like.

It is a figure which shows generation | occurrence | production of a defect in the peeling process of an imprint mold. It is a figure which shows the light intensity at the time of irradiating coherent exposure light to an imprint mold. It is a figure which shows the light intensity at the time of irradiating coherent exposure light to an imprint mold. It is a figure which shows the light intensity at the time of irradiating coherent exposure light to an imprint mold. It is a figure which shows the light intensity at the time of irradiating coherent exposure light to an imprint mold. It is a figure which shows the light intensity at the time of irradiating coherent exposure light to the imprint mold of this invention. It is a figure which shows the light intensity at the time of irradiating coherent exposure light to the imprint mold of this invention. It is a figure which shows an example of implementation of the imprint mold manufacturing method of this invention. It is a figure which shows an example of implementation of the optical imprint method of this invention.

Explanation of symbols

10 Quartz glass substrate
20 Sacrificial film 20
30 resists
40 resist pattern 50 mask pattern
60 Mold pattern 61 Mold pattern
62 Mold pattern 63 Mold pattern
70 light transmission material 90 phase displacement layer
100 Mold 110 Transfer substrate
120 Photocurable resin 130 Transfer pattern
140 Uncured portion 150 Residual film
200 Coherent light 210 Curing light
300 mold

Claims (1)

A substrate,
A concavo-convex pattern provided on the substrate;
A phase displacement layer provided on the substrate surface opposite to the substrate surface on which the concave / convex pattern is formed,
The concavo-convex pattern is a concavo-convex pattern having a plurality of steps,
The phase displacement layer uses an imprint mold that is a pattern corresponding to the uneven pattern,
A photocurable resin is disposed between the uneven pattern and the transfer substrate,
In the pattern forming method of forming a transfer pattern on the transfer substrate by peeling off the imprint mold after irradiating coherent light for curing the resin and curing the resin,
The pattern forming method of irradiating the coherent light so that the resin in contact with a corner of the uneven pattern is uncured.

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