JP6394112B2 - Template manufacturing method and template - Google Patents

Description

  The present invention relates to a template manufacturing method and template used in nanoimprint lithography for transferring a fine transfer pattern onto a resin formed on a transfer substrate.

  In recent years, in semiconductor lithography, the limit of the photolithography method has been pointed out due to the problem of exposure wavelength and manufacturing cost in response to the demand for miniaturization of devices. As a countermeasure, nanoimprint lithography using nanoimprint technology has been pointed out. (NIL: Nanoimprint Lithography) is drawing attention.

  In nanoimprint lithography, a template (also referred to as a mold, stamper, or mold) on which a fine uneven transfer pattern is formed is brought into contact with a resin formed on a substrate to be transferred such as a semiconductor wafer. The shape on the front side is molded into a concavo-convex shape of the template transfer pattern, then released, and then the excess portion (residual film portion) is removed by dry etching or the like, so that the template on the resin on the substrate to be transferred This is a technique for transferring the concavo-convex shape of the transfer pattern (more specifically, the concavo-convex inverted shape).

  In this nanoimprint lithography, once a template (also referred to as a template for nanoimprinting as appropriate) is prepared, a transfer pattern with fine irregularities can be repeatedly transferred and molded, and an expensive exposure device (stepper) is not used for this transfer process. It is also economically advantageous.

  In order to transfer the template transfer pattern onto the resin of the transfer substrate with high positional accuracy by nanoimprint lithography as described above, it is necessary to precisely align the template and the transfer substrate. In general, alignment is performed by optically detecting, from the template side, an alignment mark having a concavo-convex structure provided on a template and an alignment mark provided on a transferred substrate.

Here, when the template is brought into contact with the resin formed on the substrate to be transferred, the concave structure of the alignment mark of the template is filled with the resin.
In such a state, since the refractive index of the material (generally synthetic quartz glass) constituting the template alignment mark and the refractive index of the resin are almost the same value, the template alignment mark There is a problem that it becomes difficult to optically identify the.

  In order to solve this problem, a method for optically identifying the alignment mark even when the resin is filled by forming a high refractive index material film on the concave structure of the alignment mark of the template has been proposed (for example, Patent Document 1).

For example, in the template manufacturing method described in Patent Document 1 above, as illustrated in FIG. 8, first, the concavo-convex substrate 101 (alignment mark of the alignment mark) having the transfer pattern region 120 and the alignment mark region 130 on the main surface 102. (Corresponding to a conventional template that does not have a high refractive index material film in the concave structure) (FIG. 8A), and using a technique such as sputtering, not only the alignment mark area 130 but also the transfer pattern area A visibility thin film 140 (corresponding to a highly refractive material film) is formed so as to cover 120 (FIG. 8B).
Further, a resist film 170 is formed thereon, and a stepped substrate is pressed to deform the resist film 170 so that the film thickness of the alignment mark region 130 is larger than the film thickness of the transfer pattern region 120 (FIG. 8C). )).
Thereafter, a predetermined thickness of the resist film 170 is dry etched to leave the resist film 170 only in the concave structure of the alignment mark region 130 (FIG. 8D).
Next, the exposed visibility thin film 140 is dry-etched by a predetermined amount, and finally, the resist film 170 in the concave structure of the alignment mark region 130 is removed to have the visibility thin film 140 in the concave structure of the alignment mark region 130. A template 110a is obtained (FIG. 8E).

JP 2013-168604 A

  However, in the template manufacturing method described in Patent Document 1, the high refractive material film is also formed on the bottom surface of the concave structure in the transfer pattern region in the step of forming the high refractive material film on the concave structure in the alignment mark region. Therefore, since the opening width of the concave structure in the transfer pattern region is narrower than the depth, it is difficult to completely remove the high refractive material film formed on the bottom surface of the concave structure in the transfer pattern region. Is accompanied.

  When the above-described nanoimprint lithography is performed using a template with insufficient removal of the high refractive material film formed on the bottom surface of the concave structure in the transfer pattern region, the resin pattern formed on the transfer substrate is The remaining high refractive material film does not have a desired shape and causes a defect.

  The present invention has been made in view of the above circumstances, and is capable of producing a template that enables high-precision alignment while preventing defects in a resin pattern formed on a substrate to be transferred. An object is to provide a method and a template.

That is, the invention according to claim 1 of the present invention has the first concave structure and the second concave structure in which the base is dug down from the main surface, and the opening width of the second concave structure is the first concave structure. A concavo-convex substrate preparing step for preparing a concavo-convex substrate larger than the opening width of the concave structure, and a second material having a higher refractive index than the first material constituting the base are formed on the bottom surface of the first concave structure And depositing the main surface, the side surface of the first concave structure, the side surface of the second concave structure, and the bottom surface of the second concave structure without depositing, and the second concave while leaving the second material deposited on the bottom of the structure, the comprising a main surface and removing step of removing the second material deposited on the side surface of the first concave structure, in this order, said deposition The step is a sputtering process using a sputtering target composed of a substance contained in the second material. A step, the width of the first concave structure W _1, D ₁ the depth of the first recessed structures, a width of the second concave structure W _2, the depth of the second recessed structures When the thickness is D ₂ , the angle θ formed between the perpendicular of the main surface of the concavo-convex substrate and the perpendicular of the sputtering surface of the sputter target satisfies the relationship of W ₁ / D ₁ <tan θ <W ₂ / D _2. It is a manufacturing method of the template characterized by the above-mentioned.

Further, in the invention according to claim 2 of the present invention, an angle θ formed by a perpendicular of the main surface of the concavo-convex substrate and a perpendicular of the sputtering surface of the sputtering target is W ₁ / D ₁ <tan θ <W ₂ / 2D ₂ . The template manufacturing method according to claim 1 , wherein the relationship is satisfied.

The invention according to claim 3 of the present invention, in the sputtering process, and the normal of the main surface to the shaft of claim 1 or claim 2, characterized in that rotating the uneven substrate It is a manufacturing method of a template.

The invention according to claim 4 of the present invention is a template having a first concave structure and a second concave structure in which a base portion is dug down from a main surface, and the bottom surface of the second concave structure is the first concave structure. A second material having a refractive index larger than the bottom surface of the first concave structure and having a higher refractive index than the first material constituting the base on the bottom surface of the second concave structure and the side surface of the second concave structure; The cross-sectional shape of the film composed of the second material formed on the bottom surface of the second concave structure is formed at the center in the width direction of the second concave structure. The main film, the first concave structure, and the first film have a thickness that is thicker than the film thickness at a position in contact with the second material formed on the side surface of the second concave structure. The main surface side of the side surface of the concave structure 2 is not formed with a film made of the second material. Is a template, wherein the exposed.

According to the present invention, the high refractive material film can be formed on the bottom surface of the concave portion of the alignment mark while preventing the high refractive material film from being formed on the bottom surface of the concave portion of the transfer pattern of the template.
Therefore, by using a template manufactured by the manufacturing method according to the present invention, it is possible to perform high-precision alignment while preventing the resin pattern formed on the transferred substrate from causing defects. Can do.

It is a schematic process drawing which shows an example of the manufacturing method of the template which concerns on this invention. It is a figure explaining an example of the deposition process of the manufacturing method of the template which concerns on this invention. It is a figure explaining the relationship of each concave structure in an example of the deposition process of the manufacturing method of the template which concerns on this invention. It is a figure explaining the example of a form of the 2nd material in an example of the deposition process of the manufacturing method of the template concerning the present invention. It is a schematic process drawing which shows an example of the removal process of the manufacturing method of the template which concerns on this invention. FIG. 6 is a schematic process diagram illustrating an example of a removing process of the template manufacturing method according to the present invention, following FIG. 5. It is a figure explaining an example of the template concerning the present invention. It is a figure explaining an example of the manufacturing method of the conventional template.

  Hereinafter, a template manufacturing method and a template according to the present invention will be described in detail.

<Template manufacturing method>
First, a template manufacturing method according to the present invention will be described.
FIG. 1 is a schematic process diagram showing an example of a template manufacturing method according to the present invention.
As shown in FIG. 1, the template manufacturing method according to the present invention includes a first concave structure 13 and a second concave structure 14 in which a base 11 is dug down from a main surface 12, and the second concave structure 14. A concavo-convex substrate preparing step for preparing the concavo-convex substrate 1 having an opening width W ₂ larger than the opening width W _{1 of} the first concave structure 13 (FIG. 1A), than the first material constituting the base 11 A deposition step of depositing a second material 31 having a high refractive index on the main surface 12, the side surface of the first concave structure 13, the side surface of the second concave structure 14, and the bottom surface of the second concave structure 14; (FIG. 1 (b)), while leaving the second material 31 deposited on the bottom surface of the second concave structure 14, the second material 31 deposited on the main surface 12 and the side surfaces of the first concave structure. The removal process to remove (FIG.1 (c)) is provided in order.
Each of the above steps will be described in detail below.

(Uneven substrate preparation process)
As shown in FIG. 1A, the concavo-convex substrate 1 prepared in the present invention has a first concave structure 13 and a second concave structure 14 in which a base 11 is dug from a main surface 12, The opening width W ₂ of the _second concave structure 14 is larger than the opening width W ₁ of the first concave structure 13.
Similar to the concavo-convex substrate 101 shown in FIG. 8, the concavo-convex substrate 1 corresponds to a conventional template that does not have a high refractive index material film in the concave structure of the alignment mark. It corresponds to the concave structure (the concave structure 113 shown in FIG. 8A) constituting the template transfer pattern, and the second concave structure 14 is a concave structure (FIG. 8A) constituting the conventional template alignment mark. The concave structure 114) shown in FIG.

  Although the material (1st material) which comprises said uneven substrate 1 will not be specifically limited if it can be applied as a template used for nanoimprint lithography, Generally, synthetic quartz glass is used suitably.

The size of the first concave structure 13 is not particularly limited as long as it can be applied as the template transfer pattern. For example, the opening width W ₁ is approximately 10 nm to 40 nm. Yes, the depth is about 30 nm to 100 nm.

The size of the second concave structure 14 is not particularly limited as long as it can be applied as the alignment mark of the template. For example, the opening width W ₂ is approximately 30 nm to 5 μm. is there.
As for the depth, since the depth of the alignment mark of the template is usually the same as the transfer pattern, the depth of the second concave structure 14 is also the same as the depth of the first concave structure 13, The size is approximately in the range of about 30 nm to 100 nm.

In FIG. 1, in order to avoid complication, the embodiment in which the concavo-convex substrate 1 has only one second concave structure 14 is schematically shown, but the present invention is limited to this embodiment. Alternatively, a plurality of second concave structures 14 may be provided.
Usually, an actual template has a plurality of second concave structures 14, and the alignment mark is configured by a repetitive pattern of a concavo-convex structure including the plurality of second concave structures 14.
Further, in an actual template, alignment marks having the above-described configuration are usually provided at a plurality of locations on the main surface.

(Deposition process)
Next, the above deposition process will be described.
As shown in FIG. 1B, in the present invention, the second material 31 having a refractive index higher than that of the first material constituting the base 11 of the concavo-convex substrate 1 is changed to the main surface 12 and the first concave. It is deposited on the side surface of the structure 13, the side surface of the second concave structure 14, and the bottom surface of the second concave structure 14.

  In order to avoid complication, FIG. 1B shows a form in which the second material 31 is deposited on the main surface 12 and the bottom surface of the second concave structure 14. As shown in FIG. 4 described later, the second material 31 is deposited also on the side surface 13S of the first concave structure 13 and the side surface 14S of the second concave structure 14.

In the present invention, any material can be used as the second material 31 as long as it has a higher refractive index than the first material constituting the base 11 of the concavo-convex substrate 1.
Here, as described above, the uneven substrate 1 corresponds to a conventional template, and the first material is generally synthetic quartz glass. Then, the refractive index in the light of a wavelength of 633nm of which is the main component silicon oxide synthetic silica glass (SiO ₂₎ is 1.45.
Therefore, the second material 31 is a material having a refractive index higher than 1.45 in light having a wavelength of 633 nm, and more preferably a material having a refractive index in light having a wavelength of 633 nm of 1.7 or more. is there.

In the present invention, without depositing the second material 31 on the bottom surface of the first concave structure 13, the main surface 12, the side surface of the first concave structure 13, the side surface of the second concave structure 14, and The second material 31 is preferably deposited on the bottom surface of the second concave structure 14.
In such a deposition process, as shown in FIG. 2, the sputter target 20 composed of the substance contained in the second material 31 is applied to the main surface 12 of the concavo-convex substrate 1 so that the direction 42 of the sputter surface 21 is perpendicular. On the other hand, it is possible to suitably use a method in which sputtering film formation is performed in a predetermined direction.

  In this case, the second material 31 is preferably formed by the above-described sputtering film formation, and examples thereof include a material containing at least one metal material and its oxide, nitride, oxynitride and the like. it can. Specific examples of the metal material include chromium (Cr), molybdenum (Mo), tantalum (Ta), tungsten (W), zirconium (Zr), titanium (Ti), and the like.

  FIG. 2 is a schematic diagram for explaining the outline of an example of the deposition process according to the present invention. For example, the size and shape of the sputtering target 20 and the distance to the concavo-convex substrate 1 are actually It is different depending on the device applied to the above.

  Hereinafter, the reason why the second material 31 can be deposited on the bottom surface of the second concave structure without being deposited on the bottom surface of the first concave structure 13 by the deposition step shown in FIG.

FIG. 3 is a diagram for explaining the relationship between the concave structures in an example of the deposition process of the template manufacturing method according to the present invention.
Here, FIG. 3A is a diagram for explaining the relationship between the first concave structure 13 of the concavo-convex substrate 1 and the sputtering direction 42, and FIGS. 3B and 3C are views of the first concavo-convex substrate 1. It is a figure explaining the relationship between the concave structure 14 of 2 and the direction 42 of sputtering.
Note that the above-described direction 42 is a direction perpendicular to the sputtering surface 21 of the sputtering target 20 shown in FIG. 2, and is a direction in which a substance constituting the second material 31 flies toward the uneven substrate 1.

  For ease of explanation, the first concave structure 13 shown in FIG. 3A has a side surface 13S perpendicular to the main surface 12 and a bottom surface 13B parallel to the main surface 12. The opening width is the same as the width of the bottom surface 13B. Similarly, in the second concave structure 14 shown in FIGS. 3B and 3C, the side surface 14S is perpendicular to the main surface 12, and the bottom surface 14B is parallel to the main surface 12. The opening width is the same as the width of the bottom surface 13B.

First, the relationship between the first concave structure 13 and the direction 42 shown in FIG.
As shown in FIG. 3A, when the opening width (the same as the width of the bottom surface 13B) of the first concave structure 13 is W ₁ and the depth is D ₁ , the perpendicular 41 of the main surface 12 and the direction 42 The angle θ ₁ formed is
W ₁ / D ₁ <tan θ ₁
If the above relationship is satisfied, the substance flying along the direction 42 can reach the side surface 13S, but is blocked by the main surface 12 and cannot reach the bottom surface 13B.

Next, the relationship between the second concave structure 14 shown in FIGS. 3B and 3C and the direction 42 will be described.
As shown in FIG. 3B, when the opening width (the same as the width of the bottom surface 14B) of the second concave structure 14 is W ₂ and the depth is D ₂ , the perpendicular 41 of the main surface 12 and the direction 42 The angle θ ₂ formed is
tanθ ₂ <W ₂ / D ₂
If the relationship is satisfied, the substance flying along the direction 42 can reach the bottom surface 14B.
Further, as shown in FIG. 3C, the angle θ ₂ formed between the perpendicular 41 to the main surface 12 and the direction 42 is
tanθ ₂ <W ₂ / 2D ₂
If the relationship is satisfied, the substance flying along the direction 42 can reach the center of the bottom surface 14B.

From the above description, the angle θ between the perpendicular 41 and the direction 42 with respect to the main surface 12 of the concavo-convex substrate 1 is
W ₁ / D ₁ <tan θ <W ₂ / D ₂
If the relationship is satisfied, the substance flying along the direction 42 can reach the bottom surface 14B of the second concave structure 14 without reaching the bottom surface 13B of the first concave structure 13.
further,
W ₁ / D ₁ <tan θ <W ₂ / 2D ₂
If the above relationship is satisfied, the substance flying along the direction 42 can reach the center of the bottom surface 14B of the second concave structure 14 without reaching the bottom surface 13B of the first concave structure 13. It becomes possible.

That is, in the present invention, the angle θ formed by the perpendicular 41 of the principal surface 12 of the concavo-convex substrate 1 and the perpendicular of the sputtering surface 21 of the sputtering target 20 shown in FIG.
W ₁ / D ₁ <tan θ <W ₂ / D ₂
By disposing the concavo-convex substrate 1 and the sputter target 20 so as to satisfy the relationship, the second material 31 is not deposited on the bottom surface 13B of the first concave structure 13, and the second concave structure 14 is not deposited. It can be deposited on the bottom surface 14B.

Furthermore, the angle θ formed by the perpendicular 41 of the principal surface 12 of the concavo-convex substrate 1 and the perpendicular of the sputtering surface 21 of the sputtering target 20 shown in FIG.
W ₁ / D ₁ <tan θ <W ₂ / 2D ₂
By disposing the concavo-convex substrate 1 and the sputter target 20 so as to satisfy the relationship, the second material 31 is not deposited on the bottom surface 13B of the first concave structure 13, and the second concave structure 14 is not deposited. It is possible to deposit in the center of the bottom surface 14B.

  Here, in the present invention, as shown in FIG. 2, it is preferable to deposit the second material 31 while rotating the concavo-convex substrate 1 around the perpendicular 41. This is because the second material 31 can be deposited on the bottom surface of the second concave structure 14 so as to be substantially symmetrical with respect to the center of the second concave structure 14.

In the example shown in FIG. 2, the vertical line 41 serving as the axis of rotation of the concavo-convex substrate 1 is described at the substantially center position of the concavo-convex substrate 1, but in the present invention, the vertical line 41 is not limited to this. Any straight line that intersects perpendicularly with the plane including the main surface 12 of the concavo-convex substrate 1 may be used.
For example, the perpendicular 41 serving as the axis of rotation of the concavo-convex substrate 1 may be closer to the end of the main surface 12 of the concavo-convex substrate 1 than the example shown in FIG. The thing which has the leg of a perpendicular (intersection of the plane containing the main surface 12 of the uneven | corrugated board | substrate 1, and a perpendicular) in the plane containing the main surface 12 of the uneven | corrugated board | substrate 1 outside the edge part of 12 may be sufficient.

  The form of the second material 31 deposited as described above is the form shown in FIG. 4A in the first concave structure 13, and FIG. 4B in the second concave structure 14. It becomes a form as shown in.

More specifically, first, in the first concave structure 13, as shown in FIG. 4A, the second material 31 is deposited on the main surface 12 and the side surface 13S, but not on the bottom surface 13B. .
Although depending on the film thickness of the second material 31 to be deposited and the angle θ, the opening of the first concave structure 13 is closed as the second material 31 is deposited and grown. For this reason, the deposition of the second material 31 hardly proceeds on the side surface 13S in the region near the bottom surface 13B.
In the example shown in FIG. 4A, the second material 31 is not deposited on the side surface 13S in the region having the height T ₁ from the bottom surface 13B.

  On the other hand, in the second concave structure 14, as shown in FIG. 4B, the second material 31 is deposited on the main surface 12, the side surface 14S, and the bottom surface 14B.

Here, the corner portion constituted by the bottom surface 14B and the side surface 14S has a cross-sectional angle of 90 degrees, and the space is narrower than the other flat regions of the bottom surface 14B and the side surface 14S, so that it flies from the sputter target 20. The substance is difficult to reach, and therefore the second material 31 is difficult to deposit at this corner portion.
Further, the above action is promoted along with the deposition growth of the second material 31, and the corner portion constituted by the second material 31 deposited on the bottom surface 14B and the second material 31 deposited on the side surface 14S is formed. The cross-sectional angle θ ₃ becomes an angle (acute angle) smaller than 90 degrees.

Therefore, although depending on the angle θ and the thickness of the second material 31 to be deposited, the form of the second material 31 usually deposited on the bottom surface 14B is such that the thickness T _{2 at} the center is the surrounding thickness. It becomes a thicker form.
More particularly, usually in the form of a second material 31 deposited on the bottom surface 14B, the thickness T ₂ in the center, thicker form than the thickness T ₃ at a position in contact with the second material 31 deposited on the side surface 14S become.
For this reason, also in the template 2 (template 2 shown in FIG. 1) obtained by the present invention, the cross-sectional shape of the film composed of the second material 31 on the bottom surface of the second concave structure 14 is usually the second shape. The film thickness at the center in the width direction of the concave structure 14 is thicker than the surrounding film thickness.

(Removal process)
Next, the removal process will be described.
As shown in FIG. 1C, in the present invention, after the above-described deposition process, the second material 31 deposited on the bottom surface of the second concave structure 14 remains, and the main surface 12 and the first The second material 31 deposited on the side surface of the concave structure is removed.
As a result, there is no film composed of the second material 31 on the main surface 12, the side surface of the first concave structure 13, and the bottom surface of the first concave structure 13, and the bottom surface of the second concave structure 14. A template 2 having a film made of the second material 31 is obtained.

  In order to avoid complications, the template 2 shown in FIG. 1C shows a form in which the second material 31 does not exist on the side surface of the second concave structure 14. As shown in FIG. 7B described later, the second material 31 is also present on the side surface of the second concave structure 14 in addition to the bottom surface of the second concave structure 14.

In the above-described removal step, any material can be used without particular limitation as long as it can remove the second material 31 deposited at each of the above-mentioned locations. In the present invention, the nanoimprint technique is used. It can be used suitably.
5 and 6 are schematic process diagrams showing an example of the removal process of the template manufacturing method according to the present invention.

  First, as shown in FIG. 5A, the concavo-convex substrate 1 in which the second material 31 is deposited at a predetermined position is prepared by the above deposition process.

Next, as shown in FIG. 5B, a resin layer made of an ultraviolet curable resin between the concavo-convex substrate 1 and an ultraviolet transmissive member 52 having a flat surface facing the concavo-convex substrate 1. With the 51 interposed, the resin layer 51 is cured by irradiating the ultraviolet ray 53 from the back side of the member 52 (the surface opposite to the surface facing the concavo-convex substrate 1).
As the resin constituting the resin layer 51, an ultraviolet curable resin used in the technical field of nanoimprinting can be suitably used.

  Next, as shown in FIG. 5C, the concavo-convex substrate 1 having the resin layer 51 having a flat surface on the second material 31 is obtained by separating the member 52 from the cured resin layer 51.

Next, as shown in FIG. 6D, the resin layer 51 of the second material 31 deposited on the main surface 12 is eliminated by dry etching using the first etching gas 61, and the first Etching is performed such that the film thickness T ₄ of the resin layer 51 in the concave structure 13 and the film thickness T ₅ of the resin layer 51 in the second concave structure 14 become a predetermined film thickness.
As the first etching gas 61, oxygen gas can be used.

Here, the predetermined film thickness to be satisfied by the film thickness T ₄ of the resin layer 51 in the first concave structure 13 is that the film thickness of the resin layer 51 in the first concave structure 13 is T ₄ . For example, the film thickness is such that the second material 31 deposited on the side surface of the first concave structure 13 can be completely exposed. Specifically, the value of the film thickness T ₄ is as shown in FIG. ) Is a value smaller than the value of the height T ₁ shown in FIG.

On the other hand, the predetermined film thickness T ₅ of the resin layer 51 in the second concave structure 14 is to be satisfied if the film thickness of the resin layer 51 in the second concave structure 14 is T _5. The film thickness is such that the second material 31 deposited on the bottom surface of the second concave structure 14 can be covered without being exposed. Specifically, the value of the film thickness T ₅ is as shown in FIG. The value is larger than the value of the film thickness T ₂ shown in b).

If the above condition is satisfied, the film thickness T ₄ of the resin layer 51 in the first concave structure 13 and the film thickness T ₅ of the resin layer 51 in the second concave structure 14 are the same. It may be a value.

Next, as shown in FIG. 6E, the second material 31 exposed from the resin layer 51 is removed by dry etching using the second etching gas 62. Thus, the second material 31 deposited on the main surface 12 and the side surfaces of the first concave structure 13 can be removed while leaving the second material 31 deposited on the bottom surface of the second concave structure 14. it can.
As said 2nd etching gas 62, when the 2nd material 31 contains chromium (Cr), the mixed gas of chlorine gas and oxygen gas can be used suitably, for example.

  Next, as shown in FIG. 6F, the resin layer 51 in the first concave structure 13 and the resin layer in the second concave structure 14 are formed by dry etching using the first etching gas 61. 51, and a film made of the second material 31 is formed on the main surface 12, the side surface of the first concave structure 13, and the bottom surface of the first concave structure 13, as shown in FIG. A template 2 that does not exist and has a film made of the second material 31 on the bottom surface of the second concave structure 14 is obtained.

5 and 6 show an example in which the resin layer 51 having a flat surface is formed over the entire region on the main surface side of the concavo-convex substrate 1 using the member 52 as shown in FIG. 5C. However, as another example of using imprinting, as shown in FIG. 8C, the stepped substrate is pressed so that the film thickness of the alignment mark region 130 becomes thicker than the film thickness of the transfer pattern region 120. Thus, a method of deforming the resist film 170 may be used.
That is, in the present invention, instead of the resin layer 51 having a flat surface shown in FIG. 5C, the film thickness on the second concave structure 14 is larger than the film thickness on the first concave structure 13. A method of forming a thick resin layer having a step structure may be used.

<Template>
Next, the template according to the present invention will be described.
FIG. 7 is a diagram for explaining an example of a template according to the present invention. Here, FIG. 7A is the same as FIG. 1C, and FIG. 7B is a schematic enlarged view of the second concave structure 14 of FIG. 7A.

  In order to avoid complication, in the template 2 shown in FIG. 7A, the second material 31 is formed on the side surface of the second concave structure 14 in the same manner as in FIG. Although a form that does not exist is shown, actually, as shown in FIG. 7B, in addition to the bottom surface of the second concave structure 14, the second material 31 is also applied to the side surface of the second concave structure 14. Exists.

Moreover, in the template 2 shown to Fig.7 (a), in order to avoid becoming complicated, the form which has only the 2nd concave structure 14 is shown typically, but this invention is this. The shape is not limited, and a plurality of second concave structures 14 may be provided.
Usually, an actual template has a plurality of second concave structures 14, and the alignment mark is configured by a repetitive pattern of a concavo-convex structure including the plurality of second concave structures 14.
Further, in an actual template, alignment marks having the above-described configuration are usually provided at a plurality of locations on the main surface.

The template according to the present invention can be manufactured by the above-described template manufacturing method according to the present invention, and the first portion in which the base 11 is dug down from the main surface 12 as in the template 2 shown in FIG. A template having a concave structure 13 and a second concave structure 14, wherein the bottom surface of the second concave structure 14 is larger than the bottom surface of the first concave structure 13, and the bottom surface of the second concave structure 14 has a base portion 11 is formed with a film composed of the second material 31 having a higher refractive index than the first material constituting the material 11.
On the other hand, the second material 31 does not exist on the bottom and side surfaces of the first concave structure 13 of the template 2.
Here, the first concave structure 13 constitutes a transfer pattern of the template 2, and the second concave structure 14 constitutes an alignment mark of the template 2.

Therefore, when nanoimprint lithography is performed using this template 2, the second material 31 does not exist on the bottom surface and side surface of the first concave structure 13 constituting the transfer pattern. It can prevent that the resin pattern formed produces a defect.
Moreover, since the film | membrane comprised from the 2nd material 31 which has a high refractive index is formed in the bottom face of the 2nd concave structure 14 which comprises an alignment mark, highly accurate alignment is attained.

Note that the cross-sectional shape of the film made of the second material 31 formed on the bottom surface of the second concave structure 14 of the template 2 shown in FIG. The film thickness at the center in the direction parallel to the X direction is thicker than the surrounding film thickness.
The More particularly, as shown in FIG. 7 (b), the sectional shape of the film and a second material 31 which is formed on the bottom surface 14B, the film thickness T ₂ in the middle, formed on the side surface 14S 2 is thicker than the film thickness T _{3 at the} position in contact with the material 31.

The reason for having such a form is that the template 2 is manufactured by the template manufacturing method according to the present invention.
The thickness T ₂ shown in FIG. 7 (b) is the same as the thickness T ₂ shown in the FIG. 4 (b), the thickness T ₃ shown in FIG. 7 (b), in the FIG. This is the same as the film thickness T ₃ shown in FIG.
Further, the film thickness T ₅ shown in FIG. 7B is the same as the film thickness T ₅ shown in FIG.

  The template manufacturing method and the template according to the present invention have been described above, but the present invention is not limited to the above 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 Uneven substrate 2 Template 11 Base 12 Main surface 13 First concave structure 14 Second concave structure 20 Sputter target 21 Sputter surface 31 Second material 41 Perpendicular 42 Direction 51 Resin layer 52 Member 53 Ultraviolet ray 61 First etching gas 62 Second etching gas 101 Uneven substrate 110a Template 102 Main surface 113, 114 Concave structure 120 Transfer pattern region 130 Alignment mark region 140 Visible thin film 170 Resist film

Claims (4)

A concavo-convex substrate having a first concave structure and a second concave structure in which a base portion is dug down from a main surface, the opening width of the second concave structure being larger than the opening width of the first concave structure is prepared. An uneven substrate preparation process;
Without depositing a second material having a higher refractive index than the first material constituting the base on the bottom surface of the first concave structure, the main surface, the side surface of the first concave structure, A deposition step of depositing on a side surface of the second concave structure and a bottom surface of the second concave structure;
A removing step of removing the second material deposited on the main surface and the side surface of the first concave structure, while leaving the second material deposited on the bottom surface of the second concave structure;
In order ,
The deposition step comprises:
A sputter film forming step using a sputter target composed of a substance contained in the second material,
The width of the first concave structure is W ₁ ,
The depth of the first concave structure is D ₁ ,
The width of the second concave structure is W ₂ ,
The depth of the second concave structure is D ₂ ,
If
The angle θ formed between the perpendicular of the main surface of the uneven substrate and the perpendicular of the sputtering surface of the sputter target is
W ₁ / D ₁ <tan θ <W ₂ / D ₂
A template manufacturing method characterized by satisfying the relationship : The angle θ formed between the perpendicular of the main surface of the uneven substrate and the perpendicular of the sputtering surface of the sputter target is
W ₁ / D ₁ <tan θ <W ₂ / 2D ₂
The template manufacturing method according to claim 1, wherein: 3. The template manufacturing method according to claim 1, wherein in the sputter film forming step, the concavo-convex substrate is rotated about a perpendicular of the main surface . 4. A template having a first concave structure and a second concave structure in which a base is dug down from a main surface,
The bottom surface of the second concave structure is larger than the bottom surface of the first concave structure;
A film made of a second material having a higher refractive index than the first material constituting the base is formed on the bottom surface of the second concave structure and the side surface of the second concave structure. ,
The cross-sectional shape of the film made of the second material formed on the bottom surface of the second concave structure is
The film thickness at the center in the width direction of the second concave structure has a form thicker than the film thickness at the position in contact with the second material formed on the side surface of the second concave structure,
The main surface side of the main surface, the first concave structure, and the side surface of the second concave structure is not formed with a film made of the second material, and is exposed. A template featuring

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