JP2013089939A - Template for imprint, manufacturing method therefor, and imprint method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a template for imprint which allows for optical identification of an alignment mark of uneven structure, and alignment with high alignment accuracy without requiring a formation technique or a processing technique of a high refractive index material, and to provide a manufacturing method of a template for imprint, and an imprint method.SOLUTION: A high energy beam-sensitive glass substrate including an ion exchange surface layer containing silver ions is used as a template substrate. Optical density for the light in visible light range at a protrusion of an alignment mark is set higher than that at a recess of the alignment mark.

Description

  The present invention relates to a template used in imprint lithography for transferring a fine concavo-convex pattern onto a transfer resin formed on a transfer substrate, a manufacturing method thereof, and an imprint method.

  In recent years, especially for semiconductor devices, high speed operation and low power consumption operation are required due to further progress in miniaturization, and high technology such as integration of functions called system LSIs is required. Under such circumstances, the lithography technology that is necessary for producing the pattern of the semiconductor device has become very expensive as the exposure apparatus and the like as the pattern becomes finer, and the price of the mask used therefor also becomes expensive. Yes.

  On the other hand, the nanoimprint method (also called imprint method) proposed by Chou et al. In Princeton University in 1995 is a fine pattern forming technology having a high resolution of about 10 nm while the apparatus price and the materials used are low. (Patent Document 1).

  In the imprint method, a template (also referred to as a mold, stamper, or mold) in which a nanometer-sized fine concavo-convex pattern is formed on the surface in advance is brought into contact with a transfer resin formed on the transfer substrate surface such as a semiconductor wafer. Then, the transferred resin is mechanically deformed to transfer the uneven pattern, and the transferred substrate is processed using the transferred resin as a mask. Once a template is made, nanostructures can be easily and repeatedly molded, resulting in high throughput and economics, and because it is a processing technology with little harmful waste, it is not limited to semiconductor devices in recent years. Application to various fields is expected.

As such an imprint method, there are known a thermal imprint method in which a concavo-convex pattern is transferred by heat using a thermoplastic resin, and an optical imprint method in which a concavo-convex pattern is transferred by ultraviolet rays using an ultraviolet curable resin. (Patent Document 2).
In the optical imprint method, patterns can be transferred at room temperature and at a low applied pressure, and the heating and cooling cycle unlike the thermal imprint method is not required. It can reduce the risk that occurs, and is excellent in terms of resolution, alignment accuracy, and productivity.

Here, when the concavo-convex pattern is transferred to the transfer substrate using the imprint method as described above, it is necessary to precisely align the template and the transfer substrate.
Generally, alignment is performed by optically detecting the alignment mark provided on the template and the alignment mark provided on the transfer substrate from the template side.

FIG. 9 is an explanatory view showing an example of a conventional imprint template. FIG. 9A is a schematic cross-sectional view of the entire template, and FIG. 9B is an enlarged view of the alignment mark in FIG.
As shown in FIG. 9A, generally, the imprint template 101 has a mesa structure made of a transparent template substrate 102 such as quartz, and the transfer pattern 103 and the alignment mark 104 are formed on the top surface of the mesa structure. have.
As shown in FIG. 9B, the alignment mark 104 is usually a mark having a step structure obtained by processing the template substrate 102 into a concavo-convex shape, and has a convex portion 104a and a concave portion 104b.
Examples of the planar shape of the alignment mark include those in which one or more rectangular and cross-shaped shapes are arranged, and those having a periodic structure such as moire fringes.

  Next, a method for detecting an alignment mark in a conventional imprint template will be described. FIG. 10 is an explanatory diagram illustrating a method for detecting an alignment mark in a conventional imprint template. Here, FIG. 10A shows the state of the imprint template, the resin layer to be transferred, and the substrate to be transferred when the alignment mark is detected, and FIG. 10B shows the relationship between the convex part and the concave part in the alignment mark. .

As shown in FIG. 10A, when transferring the transfer pattern of the imprint template 101, first, the imprint template is applied to the transfer target resin layer 121 formed on the transfer substrate 111 before being cured. The surface of the imprint template 101 on which the transfer pattern 103 is formed is brought into contact with the surface of the imprint template 101 on the side opposite to the side on which the transfer pattern 103 is formed (back surface). Then, the alignment mark 115 in the alignment mark region 114 on the substrate side is optically detected, and the template 101 and the transferred substrate 111 are moved relative to each other so as to correct the positional deviation, thereby aligning the positions of both.
Then, the transferred resin layer 121 is cured in the aligned state, whereby the transfer pattern 103 of the template 101 is transferred to the transferred resin layer 121.
The alignment mark 115 on the substrate side is formed in a layered manner in the substrate and is made of copper, aluminum or the like and can be detected optically.

  As described above, the alignment is performed in a state where the template 101 is in contact with the transferred resin layer 121 on the transferred substrate 111 after the alignment is performed while the template 101 is separated from the transferred resin layer 121. This is because in the method in which the template 101 is brought into contact with the transferred resin layer 121, a positional shift (so-called lock shift) occurs in the process of bringing the template 101 into contact with the transferred resin layer 121.

JP-T-2004-504718 JP 2002-93748 A JP 2007-103915 A JP-T-60-501950 JP-A-6-59437

As described above, when the template 101 is brought into contact with the transferred resin layer 121 for alignment, as shown in FIG. 10B, the recesses of the alignment marks of the template 101 form the resin constituting the transferred resin layer 121. Will be charged.
In such a state, the refractive index of the material (generally quartz) constituting the alignment mark of the template 101 and the refractive index of the resin constituting the transferred resin layer 121 are almost the same value. Therefore, there is a problem that it becomes difficult to optically identify the alignment mark of the template 101.

  Generally, in a structure made of a transparent material, when a material having a significantly different refractive index is in contact, the shape of the structure can be recognized by light refraction, scattering, or reflection at the interface. However, when the difference in refractive index is small as described above, it is difficult to recognize the shape of the structure.

  For example, as shown in FIG. 10 (b), the light enters the convex portion and concave portion of the alignment mark of the template 101 from the back side of the template 101 (upper side in FIG. 10 (b)) and passes through the resin layer 121 to be transferred. The difference in the optical path lengths of the detection lights 132a and 132b reflected from the surface of the transferred substrate 111 is that the refractive index of the material constituting the template 101 is n1, the refractive index of the resin constituting the transferred resin layer 121 is n2, and the template 101 If the step between the convex and concave portions of the alignment mark is t, 2 × t × | n2−n1 |.

Here, as the detection light 132a and 132b, light in a wavelength region where the transferred resin layer 121 is not cured is used, and generally a wavelength in the visible light region (380 nm to 750 nm) is used.
The refractive index of quartz (SiO ₂ ), which is a general template material, at a wavelength of 633 nm is 1.45, and the refractive index of the transferred resin used in the imprint method is generally 1.5. Degree.

  Therefore, for example, assuming that a light source having a single wavelength of 633 nm is used as the light source of the detection light, the step t between the convex portion and the concave portion of the alignment mark of the template 101 is 150 nm, and the refractive index n1 of the material constituting the template 101 is set. When the above equation is calculated with 1.45 and the refractive index n2 of the resin constituting the transferred resin layer 121 is 1.50, the optical path length difference obtained is 15 nm, which is about 1/40 of the wavelength of 633 nm. Therefore, it is difficult to satisfactorily identify the alignment mark having the concavo-convex structure.

  In response to this problem, for example, even when the alignment mark is made of a high refractive index material such as titanium oxide (refractive index 2.4) and the resin to be transferred is filled in the recess of the alignment mark, the high refractive index There has been proposed a method for optically identifying alignment marks having a concavo-convex structure so that a difference is generated between the refractive index of the material and the refractive index of the resin to be transferred (Patent Document 3).

  However, the above-described method requires a technique for forming a high refractive index material such as titanium oxide on the template in addition to the conventional template manufacturing technique, and a technique for processing the alignment mark into the concavo-convex structure. This is not preferable because the process becomes complicated.

  The present invention has been made in view of the above circumstances, and enables the alignment mark of the concavo-convex structure to be optically identified without requiring the formation technique and processing technique of the high refractive index material, and has high alignment accuracy. It is an object of the present invention to provide an imprint template, an imprint template manufacturing method, and an imprint method that can be aligned with each other.

  As a result of various studies, the present inventor has used a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions as a template substrate, and the optical density with respect to light in the visible light region at the convex portion of the alignment mark, The present invention has been completed by finding that the above problem can be solved by making the optical density higher than the optical density of light in the visible light region in the concave portion of the alignment mark.

  That is, the invention according to claim 1 of the present invention is an imprint template having a concavo-convex structure transfer pattern and a concavo-convex structure alignment mark, the imprint template containing an ion-exchange surface layer containing silver ions. The optical density for the light in the visible light region at the convex portion of the alignment mark is higher than the optical density for the light in the visible light region at the concave portion of the alignment mark. This is an imprint template.

  Further, in the invention according to claim 2 of the present invention, the depth of the recess of the alignment mark is larger than the thickness of the ion exchange surface layer. It is a template.

  The invention according to claim 3 of the present invention includes a step of etching a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions to form an alignment mark having a concavo-convex structure, and the concavo-convex structure. Irradiating the alignment mark with a high energy beam, and a method for producing an imprint template.

  According to a fourth aspect of the present invention, there is provided a step of irradiating a predetermined part of a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions with a high energy beam, Etching the predetermined portion to form an alignment mark having a concavo-convex structure, and a method for producing an imprint template.

  According to a fifth aspect of the present invention, there is provided a process for forming a transferred resin layer on a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions, and the transferred resin layer. A step of contacting the concavo-convex structure transfer pattern and the concavo-convex structure alignment mark formed on the master template, a step of curing the transferred resin layer, the cured transferred resin layer and the master template, The transfer pattern formed on the master template is formed on the master template and the transfer pattern formed on the master template by etching using the cured transferred resin layer as a mask. The alignment mark with the irregularities reversed is the high energy beam sensitive glass substrate. Forming in a manufacturing method of the high-energy beam to alignment marks formed on the sensitive glass substrate high energy beams imprint template, characterized in that it comprises a step of irradiating.

  The invention according to claim 6 of the present invention includes a step of irradiating a predetermined part of a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions with a high energy beam, and the high energy beam sensitivity. Forming a transferred resin layer on a glass substrate; contacting the transferred resin layer with an uneven structure transfer pattern and an uneven structure alignment mark formed on a master template; and the transferred image Formed on the master template by a step of curing the resin layer, a step of releasing the cured resin layer to be transferred and the master template, and an etching process using the cured resin layer to be transferred as a mask The transferred pattern is a transfer pattern with the concavities and convexities reversed, and an alignment formed on the master template. An alignment mark irregularities reversed the mark put, and forming the high energy beam sensitive glass substrate, a manufacturing method of imprint templates, characterized in that it comprises a.

  Further, in the invention according to claim 7 of the present invention, the resin constituting the transferred resin layer is an ultraviolet curable resin, and the step of curing the transferred resin layer is performed by irradiating ultraviolet rays to the transferred resin. It is a process of hardening a layer, It is a manufacturing method of the template for imprint in any one of Claims 5-6 characterized by the above-mentioned.

  In the invention according to claim 8 of the present invention, in the step of forming the uneven alignment mark, the depth of the recessed portion of the alignment mark to be formed is larger than the thickness of the ion exchange surface layer. The method for producing an imprint template according to claim 3, wherein the high energy beam sensitive glass substrate provided with the ion exchange surface layer containing silver ions is etched.

  The invention according to claim 9 of the present invention uses the imprint template according to any one of claims 1 to 2, and the uneven structure of the template is formed on the transferred resin layer formed on the transferred substrate. The alignment mark of the concavo-convex structure and the alignment mark were contacted, and the alignment mark was optically detected by the difference in optical density between the concave and convex portions of the alignment mark, and the template and the substrate to be transferred were aligned. Later, the transferred resin layer is cured, the cured transferred resin layer and the template are released, and a pattern in which the unevenness is reversed from the transfer pattern of the uneven structure of the template is transferred to the transferred resin layer. It is an imprint method characterized by forming in the following.

  In the invention according to claim 10 of the present invention, the resin constituting the transferred resin layer is an ultraviolet curable resin, and the step of curing the transferred resin layer is performed by irradiating ultraviolet rays to the transferred resin. The imprint method according to claim 9, wherein the method is a step of curing the layer.

  According to the present invention, the alignment mark can be optically identified based on the difference in optical density between the convex portion and the concave portion of the alignment mark having the concavo-convex structure. Therefore, the template and the transferred substrate can be aligned with high alignment accuracy, and the transfer pattern of the template can be imprinted on the transferred substrate with high positional accuracy.

It is typical sectional drawing which shows the example of the template for imprint which concerns on this invention. It is a figure explaining the relationship between the depth of the recessed part of the alignment mark of the imprint template which concerns on this invention, and the thickness of an ion exchange surface layer. It is explanatory drawing which shows the detection method of the alignment mark in the template for imprint which concerns on this invention. It is a typical process figure showing an example of a manufacturing method of an imprint template concerning the present invention. FIG. 5 is a schematic process diagram showing an example of a plate making process in the method for manufacturing an imprint template according to the present invention shown in FIG. 4. It is a typical process figure showing other examples of a manufacturing method of an imprint template concerning the present invention. FIG. 7 is a schematic process diagram showing an example of a plate making process in the method for manufacturing an imprint template according to the present invention shown in FIG. 6. It is a typical process figure showing an example of an imprint method concerning the present invention. It is explanatory drawing which shows the example of the conventional template for imprint, (a) shows typical sectional drawing of the whole template, (b) shows the enlarged view of the alignment mark in (a). It is explanatory drawing which shows the detection method of the alignment mark in the conventional template for imprint.

[Template for imprint]
First, an imprint template according to the present invention will be described.
FIG. 1 is a schematic cross-sectional view showing an example of an imprint template according to the present invention.
As shown in FIG. 1, an imprint template 1 according to the present invention comprises a template substrate 2 having a mesa structure, and a transfer pattern 3 having a concavo-convex structure and an alignment mark 4 having a concavo-convex structure are formed on the top surface of the mesa structure. Have.
Since the convex portion 4a of the alignment mark 4 is darker than the concave portion 4b, the optical density of the convex portion 4a with respect to light in the visible light region is higher than the optical density of the concave portion 4b with respect to light in the visible light region. It has become.

  The imprint template according to the present invention can optically identify an alignment mark having a concavo-convex structure based on the difference in optical density between the convex portion and the concave portion of the alignment mark. By using the imprint template according to the present invention, it is possible to perform alignment with high alignment accuracy, and it is possible to imprint the template transfer pattern on the substrate to be transferred with high positional accuracy.

  Here, the template substrate 2 according to the present invention comprises a high energy beam sensitive glass substrate (HEBS glass substrate) provided with an ion exchange surface layer 5 containing silver ions, and the ion exchange surface layer is irradiated with a high energy beam. By doing so, the alignment mark of the imprint template 1 is darkened.

  The high energy beam sensitive glass substrate (HEBS glass substrate) having an ion exchange surface layer containing silver ions described above is a glass substrate in which alkali metal ions in the surface layer are replaced with silver ions. This corresponds to a glass substrate made of a high energy beam sensitive glass article (HEBS glass article) disclosed in Japanese Patent No. 501950 (Patent Document 4).

The glass main body portion of the HEBS glass substrate is expressed in mol%, 5% to 25% of one or more alkali metal oxides, 0.5% to 35% photosensitive inhibitor (PI agent), natural red. shift inhibitor (RS- inhibitor) and mixtures thereof, has a base glass composition including SiO ₂ of 0% to 6% Cl and 50% to 89%.

On the other hand, the ion exchange surface layer of the HEBS glass substrate has a composition in which alkali metal ions in the base glass composition of the glass body portion are replaced with silver ions.
The ion exchange surface layer is formed as follows, for example.

  The HEBS glass substrate before ion exchange having the base glass composition is immersed in an acidic aqueous solution containing silver ions, sealed in an autoclave, and the silver ions in the aqueous solution and the alkali metal ions in the surface layer of the glass substrate. The glass substrate is held at a temperature sufficient to cause an ion exchange reaction in the meantime (usually at 200 ° C. or higher for 1 minute or longer), and then the glass substrate is taken out of the autoclave and washed with distilled water.

The surface layer of the glass substrate after the ion exchange (ie, the ion exchange surface layer) contains, for example, silver ions and / or a silver salt and silanol and / or water at a concentration exceeding about 0.01 wt% H ₂ O. The concentration of the alkali metal oxide in the ion exchange surface layer is lower than the concentration in the glass composition of the glass body portion.

The thickness of the ion exchange surface layer can be adjusted by controlling the temperature and time of the ion exchange reaction.
In the present invention, the thickness of the ion exchange surface layer may be a thickness that allows the alignment mark to be optically identified by the difference in optical density between the convex portion and the concave portion of the alignment mark having the concavo-convex structure. .
However, in order to further increase the difference in optical density, the thickness of the ion exchange surface layer is made the same as the depth of the recess of the alignment mark, or the depth of the recess of the alignment mark It is preferable to make it small (shallow). In other words, the depth of the recess of the alignment mark is preferably greater than or equal to the thickness of the ion exchange surface layer.
The reason will be described with reference to FIG.

FIG. 2 is a diagram for explaining the relationship between the depth of the recess of the alignment mark of the imprint template according to the present invention and the thickness of the ion exchange surface layer. 2A shows a form in which the depth (D ₁ ) of the recess 4b of the alignment mark is smaller than the thickness (D ₂ ) of the ion exchange surface layer, and FIG. 2B shows the alignment mark. In this embodiment, the depth (D ₁ ) of the recess 4b is equal to or greater than the thickness (D ₂ ) of the ion exchange surface layer.
In the present invention, neither the convex portion 3a nor the concave portion 3b of the transfer pattern is darkened, and with respect to the ultraviolet rays irradiated when the ultraviolet curable resin is cured using an imprint method, It has sufficient permeability.

For example, as shown in FIG. 2A, in the form in which the depth (D ₁ ) of the recess 4b of the alignment mark is smaller than the thickness (D ₂ ) of the ion exchange surface layer, the protrusion 4a and the recess of the alignment mark The difference in the optical density of 4b becomes an optical density corresponding to D ₁ / D ₂ , and as D ₂ becomes larger than D ₁ , the discrimination becomes difficult. Further, when darkening of the ion exchange surface layer is promoted in order to increase the optical density, not only the convex portion 4a of the alignment mark but also the concave portion 4b is darkened, so that it is difficult to identify the two. .

On the other hand, as shown in FIG. 2B, if the depth (D ₁ ) of the recess 4b of the alignment mark is larger than the thickness (D ₂ ) of the ion exchange surface layer, the alignment mark The difference in optical density between the convex part 4a and the concave part 4b depends on the optical density corresponding to the thickness of D ₂ and is not affected by D ₁ , so that the degree of freedom in processing the alignment mark increases. Moreover, if it is such a form, it will be easy to enlarge the difference of the optical density of the convex part 4a and the recessed part 4b by promoting darkening of an ion exchange surface layer.
The promotion of darkening can be achieved, for example, by irradiating with a high energy beam for a longer time. Here, the above-mentioned high energy beam is, for example, an electron beam, and a commercially available electron beam microscope or electron beam mask drawing apparatus can be used.

  Next, a method for detecting an alignment mark in the imprint template according to the present invention will be described. FIG. 3 is an explanatory diagram showing a method for detecting an alignment mark in an imprint template according to the present invention. Here, FIG. 3A shows the state of the imprint template, the resin layer to be transferred, and the substrate to be transferred when the alignment mark is detected, and FIG. 3B shows the relationship between the convex part and the concave part in the alignment mark. .

  As shown in FIG. 3A, when the transfer pattern 3 of the imprint template 1 is transferred, first, the imprinting resin layer 21 formed on the transfer substrate 11 is imprinted on the transfer resin layer 21 before being imprinted. The surface of the template 1 on which the transfer pattern 3 is formed is brought into contact, and then the surface on the template side of the imprint template 1 opposite to the side on which the transfer pattern 3 is formed (back surface) is detected by the detector 31 on the template side. The alignment mark 4 and the alignment mark 15 in the alignment mark area 14 on the substrate side are optically detected, and the template 1 and the transferred substrate 11 are relatively moved so as to correct the positional deviation, thereby moving the positions of the two. Match.

  Here, when the template 1 is brought into contact with the transferred resin layer 21 for alignment, the concave portion of the alignment mark of the template 1 is filled with the resin constituting the transferred resin layer 21 as shown in FIG. It will be in the state. In such a state, in the conventional imprint template, both the material constituting the convex portion of the alignment mark and the resin constituting the resin to be transferred 21 are detected light (for example, wavelength 633 nm) in the visible light range. On the other hand, since it is transparent and the refractive indexes of both are almost the same value, it is difficult to optically identify the alignment mark on the template side.

On the other hand, in the imprint template 1 according to the present invention, the optical density of the convex portion of the alignment mark 4 with respect to the light in the visible light region is higher than the optical density of the concave portion with respect to the light in the visible light region.
Therefore, as shown in FIG. 3B, the detection light that is incident on the convex portion of the alignment mark 4, passes through the transferred resin layer 21, is reflected on the surface of the transferred substrate 11, and is detected by the detector 31. The intensity of 32 a is incident on the recess of the alignment mark 4, passes through the transferred resin layer 21, is reflected on the surface of the transferred substrate 11, and becomes smaller than the intensity of the detection light 32 b detected by the detector 31.
By detecting this difference in intensity of the detection light, the imprint template 1 according to the present invention can satisfactorily identify the concave portion and the convex portion of the alignment mark.

The imprint template 1 and the transferred substrate 11 according to the present invention are determined from the position information from the alignment mark 4 on the template side detected as described above and the positional information from the alignment mark 15 on the transferred substrate side. Therefore, the alignment is performed with high alignment accuracy.
Further, by curing the transferred resin layer 21 in the aligned state, the transfer pattern 3 of the template 1 is transferred to the transferred resin layer 21 formed on the transferred substrate 11 with high positional accuracy. can do.

[Method for manufacturing imprint template]
Next, a method for manufacturing an imprint template according to the present invention will be described.
(First embodiment)
FIG. 4 is a schematic process diagram showing an example of a method for producing an imprint template according to the present invention.
In the method for manufacturing an imprint template according to the present invention in the present embodiment, first, as shown in FIG. 4A, a high energy beam sensitive glass provided with the above-described ion exchange surface layer 5 containing silver ions. A template substrate 2 made of a substrate is prepared, and then a mesa structure having a predetermined region on the upper surface is formed as shown in FIG. 4B.

  Next, as shown in FIG. 4C, a resist plate-making process and an etching process are performed to form a concavo-convex structure transfer pattern 3 and a concavo-convex structure alignment mark 4 on the top surface of the mesa structure. Then, as shown in FIG. 4D, the alignment mark 4 having the concavo-convex structure is irradiated with a high energy beam 41 to darken the ion-exchange surface layer 5 constituting the alignment mark 4 having the concavo-convex structure, thereby aligning the alignment mark. The imprint template 1 according to the present invention is obtained by making the optical density of visible light in the convex portion 4 higher than the optical density of light in the visible light region in the concave portion of the alignment mark 4 (FIG. 4 (e)). )).

Here, it is preferable that etching is performed so that the depth of the concave portion of the alignment mark is greater than or equal to the thickness of the ion exchange surface layer 5.
If the alignment mark is formed as described above, only the convex portion of the alignment mark can be darkened by irradiating the entire alignment mark with a high energy beam, and as described above, the convex portion of the alignment mark. This is because it is possible to easily identify the recess and the recess.

  In the present invention, the transfer pattern and the alignment mark are preferably formed by an imprint method. That is, the imprint template according to the present invention is preferably a replica template that is duplicated from a template master (master template). This is because a plurality of imprint templates (replica templates) can be manufactured from a single master template with high throughput, which is economically beneficial.

As a method for manufacturing the imprint template transfer pattern and the alignment mark according to the present invention in the present embodiment by the above-described imprint method, for example, there are the following methods.
FIG. 5 is a schematic process diagram showing an example of a plate making process in the method for manufacturing an imprint template according to the present invention shown in FIG. That is, FIG. 5 shows an example of the manufacturing process from FIG. 4 (b) to FIG. 4 (c).
First, as shown in FIG. 5A, the template substrate 2 formed in a mesa structure is prepared. Next, as shown in FIG. 5B, a separately prepared master template 6 and the template substrate are prepared. 2 are arranged opposite to each other, and a transferred resin layer 7 is formed on the ion exchange surface layer 5 of the template substrate 2.
Next, as shown in FIG. 5 (c), the transferred resin layer 7 is brought into contact with the concavo-convex structure transfer pattern formed on the master template 6 and the concavo-convex structure alignment mark, and then irradiated with ultraviolet rays 9. The transferred resin layer 7 is cured by a method such as
Thereafter, as shown in FIG. 5 (d), the transferred resin pattern 8 formed by curing the transferred resin layer 7 and the master template 6 are released from the mold, and then in FIG. 5 (e). As shown in the drawing, by using the transferred resin pattern 8 as a mask, the template substrate 2 having the ion exchange surface layer 5 is etched to form the concavo-convex structure transfer pattern 3 and the concavo-convex structure alignment mark 4. (FIG. 5 (f)).

When the transfer pattern and the alignment mark are formed using a photoimprint method, an ultraviolet curable resin is used as a resin constituting the transferred resin layer, and ultraviolet rays are irradiated in the step of curing the transferred resin layer. Thus, the transferred resin layer may be cured.
Since the optical imprint method does not require a heating / cooling cycle like the thermal imprint method, the risk of dimensional change of the template or resin due to heat can be reduced, and resolution, alignment accuracy, productivity, etc. can be reduced. Excellent in terms.

  Although not shown, in the above-described steps, a hard mask layer made of a material containing chromium (Cr) or the like is formed in advance on the ion exchange surface layer 5 of the template substrate 2, and a transferred resin layer is formed thereon. 7 and using the transferred resin pattern 8 formed as described above as a mask, the hard mask layer is first etched, and then the hard mask pattern obtained by the etching is used as a mask. The template substrate 2 having the ion exchange surface layer 5 may be etched to form the concavo-convex structure transfer pattern 3 and the concavo-convex structure alignment mark 4.

  The master template can be manufactured by a conventional method for manufacturing an imprint template. For example, a quartz substrate is used as a template substrate, an electron beam resist is applied on one main surface of the quartz substrate, and a resist pattern of transfer patterns and alignment marks is formed by electron beam drawing. By performing dry etching using a gas and then removing the remaining resist pattern, a master template having a concavo-convex structure transfer pattern and an alignment mark can be obtained.

  Note that the imprint template transfer pattern according to the present invention manufactured by the above-described imprint method is a transfer pattern in which irregularities are reversed from the transfer pattern formed on the master template. The alignment mark of the imprint template manufactured by the imprint method is an alignment mark with the concavities and convexities reversed from the alignment mark formed on the master template.

(Second Embodiment)
Next, another example of the imprint template manufacturing method according to the present invention will be described.
In the embodiment, the imprint template manufacturing method according to the present invention is obtained by processing the template substrate 2 made of the high energy beam sensitive glass substrate having the ion exchange surface layer 5 containing silver ions into a mesa structure. First, the high-energy beam 41 is irradiated to darken the ion exchange surface layer 5 at a predetermined portion (a portion where the alignment mark 4 will be formed later), and then the predetermined portion is etched to form a concavo-convex structure. An alignment mark 4 is formed.

Hereinafter, the manufacturing method of the present embodiment will be specifically described with reference to FIG.
FIG. 6 is a schematic process diagram showing another example of a method for producing an imprint template according to the present invention.
First, as shown in FIG. 6 (a), a template substrate 2 made of a high energy beam sensitive glass substrate provided with the above-described ion exchange surface layer 5 containing silver ions is prepared, and then in FIG. 6 (b). As shown, a mesa structure having a predetermined region on the upper surface is formed.
Next, as shown in FIG. 6 (c), a high-energy beam 41 is irradiated to a predetermined portion that will later form the alignment mark 4 to darken the ion exchange surface layer 5 at the predetermined portion. (FIG. 6 (d)).
Thereafter, a resist plate-making process and an etching process are performed to form the concavo-convex structure transfer pattern 3 and the concavo-convex structure alignment mark 4 on the top surface of the mesa structure. The imprint template 1 according to the present invention having the alignment mark 4 having a concavo-convex structure whose density is higher than the optical density of the light in the visible light region in the concave portion is obtained (FIG. 6E).

Here, it is preferable that etching is performed so that the depth of the concave portion of the alignment mark is greater than or equal to the thickness of the ion exchange surface layer 5.
If the alignment mark is formed as described above, only the convex portion of the alignment mark can be darkened by irradiating the entire alignment mark with a high energy beam, and as described above, the convex portion of the alignment mark. This is because it is possible to easily identify the recess and the recess.

  Also in this embodiment, as in the first embodiment, the transfer pattern and the alignment mark are preferably formed by an imprint method. This is because a plurality of imprint templates (replica templates) can be manufactured from a single master template with high throughput, which is economically beneficial.

Examples of a method for manufacturing the imprint template transfer pattern and the alignment mark according to the present invention in the present embodiment by the imprint method include the following methods.
FIG. 7 is a schematic process diagram showing an example of a plate making process in the method for manufacturing an imprint template according to the present invention shown in FIG. That is, FIG. 7 shows an example of the manufacturing process from FIG. 6 (d) to FIG. 6 (e).

First, as shown in FIG. 7A, the template substrate 2 is prepared, which is formed in a mesa structure and in which the ion exchange surface layer 5 in a predetermined part, which will be a part where the alignment mark 4 is formed later, is darkened. Next, as shown in FIG. 7B, a separately prepared master template 6 and the template substrate 2 are arranged to face each other, and a transferred resin layer 7 is formed on the ion exchange surface layer 5 of the template substrate 2. To do.
Next, as shown in FIG. 7 (c), the transferred resin layer 7 is brought into contact with the transferred pattern of the concavo-convex structure formed on the master template 6 and the alignment mark of the concavo-convex structure, and then irradiated with ultraviolet rays 9. The transferred resin layer 7 is cured by a method such as
Thereafter, as shown in FIG. 7 (d), the transferred resin pattern 8 formed by curing the transferred resin layer 7 and the master template 6 are released from the mold, and then in FIG. 7 (e). As shown in the drawing, by using the transferred resin pattern 8 as a mask, the template substrate 2 having the ion exchange surface layer 5 is etched to form the concavo-convex structure transfer pattern 3 and the concavo-convex structure alignment mark 4. (FIG. 7 (f)).

  Also in the present embodiment, as in the first embodiment, when the transfer pattern and the alignment mark are formed using the optical imprint method, an ultraviolet curable resin is used as the resin constituting the transferred resin layer. In the step of curing the transferred resin layer, the transferred resin layer may be cured by irradiating with ultraviolet rays.

  Although not shown, in this embodiment as well as in the first embodiment, in the above-described steps, a hard material made of a material containing chromium (Cr) or the like is formed on the ion exchange surface layer 5 of the template substrate 2 in advance. First, a mask layer is formed, a transferred resin layer 7 is formed thereon, the transferred resin pattern 8 formed as described above is used as a mask, the hard mask layer is first etched, and then Using the hard mask pattern obtained by the etching as a mask, the template substrate 2 having the ion exchange surface layer 5 is etched to form the concavo-convex structure transfer pattern 3 and the concavo-convex structure alignment mark 4. May be.

[Imprint method]
Next, the imprint method according to the present invention will be described.
The imprint method according to the present invention uses a template for imprinting according to the present invention having the above-described configuration, and a transfer pattern of the concavo-convex structure of the template on a transferred resin layer formed on the transferred substrate. An alignment mark having a concavo-convex structure is brought into contact, the alignment mark is optically detected based on a difference in optical density between the concave portion and the convex portion of the alignment mark, and the template and the transfer substrate are aligned. The transfer resin layer is cured, the cured transfer resin layer and the template are released, and a pattern in which the unevenness is reversed from the transfer pattern of the uneven structure of the template is formed on the transfer resin layer It is.

As described above, the imprint method includes an optical imprint method and a thermal imprint method. In the imprint method according to the present invention, it is particularly preferable to use the optical imprint method.
As described above, the ion-exchange surface layer in the imprint template according to the present invention is darkened by irradiation with a high-energy beam, but this darkened portion is restored by heat (made transparent). (Patent Document 5).
Therefore, when the thermal imprint method is used, depending on the heating conditions, the darkened portion may become transparent, and thereafter, the alignment mark cannot be detected, that is, an imprint template. This is because there is a fear that it cannot be used repeatedly.

FIG. 8 is a schematic process diagram showing an example of an imprint method according to the present invention.
In the imprint method according to the present invention, first, as shown in FIG. 8A, an imprint template 1 according to the present invention is prepared, and an uncured transferred resin layer 21 is formed on a transferred substrate 11. Form. In this example, the resin constituting the transferred resin layer 21 is an ultraviolet curable resin.

  Next, as shown in FIG. 8B, the template 1 and the resin layer 21 to be transferred are brought into contact with each other, and the position information of the substrate side alignment mark facing the template side alignment mark is detected using the detection light 32. By detecting at 31, the position of the template 1 and the substrate 11 to be transferred is aligned.

Here, since the optical density with respect to the light in the visible light region at the convex portion of the alignment mark of the imprint template 1 according to the present invention is higher than the optical density with respect to the light in the visible light region at the concave portion of the alignment mark, Due to the difference in optical density, the alignment mark of the template 1 can be well identified.
Therefore, in the imprint method according to the present invention, it is possible to align the template and the transferred substrate with high alignment accuracy, and it is possible to transfer the template transfer pattern to the transferred substrate with high positional accuracy. it can.

  Next, as shown in FIG. 8C, the resin to be transferred 21 is cured by irradiating a predetermined amount of ultraviolet rays 51, and then the template 1 is released as shown in FIG. 8D. Then, a cured transfer resin pattern 22 is obtained.

  As mentioned above, although each embodiment was described about the imprint template concerning this invention, the manufacturing method of the imprint template, and the imprint method, this invention is not limited to the said embodiment. The above-described embodiment is an exemplification, and the technical idea described in the claims of the present invention has substantially the same configuration and exhibits the same function and effect regardless of the case. It is included in the technical scope of the invention.

DESCRIPTION OF SYMBOLS 1 ... Template 2 ... Template board | substrate 3 ... Transfer pattern 3a ... Convex part 3b ... Concave part 4 ... Alignment mark 4a ... Convex part 4b ... Concave part 5 ... Ion Exchange surface layer 5a ... dark part 6 ... master template 7 ... transferred resin layer 8 ... transferred resin pattern 9 ... ultraviolet ray 11 ... transferred substrate 13 ... transferred Pattern region 14 ... Substrate side alignment mark region 15 ... Substrate side alignment mark 21 ... Transfer resin layer 22 ... Transfer resin pattern 31 ... Detector 32, 32a, 32b ... Detection Light 41 ... High energy beam 51 ... Ultraviolet light 101 ... Template 102 ... Template substrate 103 ... Transfer pattern 104 ... Alignment mark 10 4a ... convex portion 104b ... concave portion 111 ... transferred substrate 113 ... transferred pattern region 114 ... substrate side alignment mark region 115 ... substrate side alignment mark 121 ... transferred resin Layer 131 ... Detector 132, 132a, 132b ... Detection light

Claims (10)

An imprint template having an uneven structure transfer pattern and an uneven structure alignment mark,
The imprint template comprises a high energy beam sensitive glass substrate with an ion exchange surface layer containing silver ions,
An imprint template, wherein an optical density for light in a visible light region at a convex portion of the alignment mark is higher than an optical density for light in a visible light region at a concave portion of the alignment mark.   The imprint template according to claim 1, wherein the depth of the concave portion of the alignment mark is equal to or greater than the thickness of the ion exchange surface layer. Etching a high energy beam sensitive glass substrate with an ion exchange surface layer containing silver ions to form an alignment mark of a concavo-convex structure;
Irradiating the alignment mark of the concavo-convex structure with a high energy beam;
A method of manufacturing an imprint template, comprising: Irradiating a predetermined portion of a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions with a high energy beam;
Etching a predetermined portion irradiated with the high energy beam to form an alignment mark having a concavo-convex structure;
A method of manufacturing an imprint template, comprising: Forming a transferred resin layer on a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions;
Contacting the transferred resin layer with a concavo-convex structure transfer pattern and an concavo-convex structure alignment mark formed on a master template;
Curing the transferred resin layer;
Releasing the cured transferred resin layer and the master template;
Due to the etching process using the cured resin layer to be transferred as a mask, the transfer pattern formed on the master template is reversed with the transfer pattern, and the alignment mark formed on the master template is uneven. Forming an inverted alignment mark on the high energy beam sensitive glass substrate;
Irradiating the alignment mark formed on the high energy beam sensitive glass substrate with a high energy beam;
A method of manufacturing an imprint template, comprising: Irradiating a predetermined portion of a high energy beam sensitive glass substrate having an ion exchange surface layer containing silver ions with a high energy beam;
Forming a transferred resin layer on the high energy beam sensitive glass substrate;
Contacting the transferred resin layer with a concavo-convex structure transfer pattern and an concavo-convex structure alignment mark formed on a master template;
Curing the transferred resin layer;
Releasing the cured transferred resin layer and the master template;
Due to the etching process using the cured resin layer to be transferred as a mask, the transfer pattern formed on the master template is reversed with the transfer pattern, and the alignment mark formed on the master template is uneven. Forming an inverted alignment mark on the high energy beam sensitive glass substrate;
A method of manufacturing an imprint template, comprising:   The resin constituting the transferred resin layer is an ultraviolet curable resin, and the step of curing the transferred resin layer is a step of curing the transferred resin layer by irradiating with ultraviolet rays. Item 7. A method for producing an imprint template according to any one of Items 5 to 6.   In the step of forming the uneven alignment mark, the ion exchange surface layer containing the silver ions so that the depth of the recess of the alignment mark to be formed is greater than or equal to the thickness of the ion exchange surface layer. The method for producing an imprint template according to any one of claims 3 to 7, wherein the high energy beam sensitive glass substrate provided is etched. Using the imprint template according to claim 1,
The transferred resin layer formed on the transferred substrate is brought into contact with the concavo-convex structure transfer pattern of the template and the concavo-convex structure alignment mark,
Due to the difference in optical density between the concave and convex portions of the alignment mark,
After optically detecting the alignment mark and aligning the template and the transferred substrate,
Curing the transferred resin layer;
Release the cured resin layer to be transferred and the template,
An imprinting method comprising forming a pattern in which unevenness is reversed from a transfer pattern having an uneven structure of the template on the transferred resin layer. The resin constituting the transferred resin layer is an ultraviolet curable resin, and the step of curing the transferred resin layer is a step of curing the transferred resin layer by irradiating with ultraviolet rays. Item 10. The imprint method according to Item 9.

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