JP2011156738A - Method of manufacturing sub master mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To relatively easily provide a sub master mold including a precise minute pattern. <P>SOLUTION: This method of manufacturing the sub master mold 20 from a master pattern mold 30 for imprint having grooves corresponding to the minute pattern includes a minute pattern dimension fluctuation process of performing dry etching using oxygen gas with respect to a resist layer 4 which is formed on a hard mask layer formed on a substrate 1 for the sub master mold and to which the minute pattern of the master pattern mold 30 is transferred. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a sub master mold, and more particularly to a method for manufacturing a sub master mold from a master mold having a fine pattern.

  Conventionally, in a magnetic disk used in a hard disk or the like, a technique has been used in which the magnetic head width is minimized and the data tracks on which information is recorded are narrowed to increase the density. On the other hand, the density of this magnetic disk has been increased and the magnetic influence between adjacent tracks cannot be ignored. For this reason, the conventional method has a limit in increasing the density.

Recently, a new type of media called Discrete Track Recording Medium (hereinafter referred to as DTR media) in which data tracks of a magnetic disk are magnetically separated has been proposed.

  The DTR media is intended to improve signal quality by removing (grooving) a portion of magnetic material that is not necessary for recording. Specifically, after the grooves are processed, the grooves are filled with a non-magnetic material to realize angstrom level surface flatness required for a magnetic disk drive. An imprint technique is used as one of the techniques for performing this fine width groove processing. In addition, a new type of media called bit patterned media (medium for recording signals as bit patterns (dot patterns)), which has been developed by further increasing the density of this DTR media, has been proposed. Imprint technology is also considered promising in pattern formation.

  This imprint technique is roughly divided into two types, thermal imprint and optical imprint. Thermal imprinting is a method in which a mold on which a fine pattern is formed is pressed against a thermosetting resin that is a molding material while being heated, and then the molding material is cooled and released to transfer the fine pattern. Optical imprinting is a method in which a mold on which a fine pattern is formed is pressed against a photocurable resin that is a molding material, irradiated with ultraviolet light, and then the molding material is released to transfer the fine pattern. is there.

  In the mold for optical imprinting mentioned here, the master mold itself provided with a fine pattern is not usually used. Instead, a secondary mold formed by transferring the fine pattern of the master mold to another molding material, or formed by transferring the fine pattern of the secondary mold to another molding material 3 A sub master mold to which a fine pattern of the master mold is transferred, such as a next mold, is used. Even if the sub-master mold is deformed or damaged, if the master mold is safe, the sub-master mold can be manufactured.

  Although it is not directly related to the production of the sub-master mold for optical imprinting here, as a related technique, a chromium nitride layer is formed on a light-transmitting substrate such as quartz glass, and a resist is applied thereon. Later, a technique for forming a resist pattern using electron beam drawing or the like has been disclosed by the present applicant (see, for example, Patent Document 1). In this Patent Document 1, a fine pattern is formed by etching the chromium nitride layer using this resist pattern as a mask. Thereafter, the light-transmitting substrate is grooved using a fine pattern in the chromium nitride layer as a mask.

Usually, when performing optical imprinting, a liquid resist layer is used. When the sub master mold is manufactured, the master mold is placed on the liquid resist layer. At this time, since the resist is liquid, the resist layer remains between the portion other than the groove in the master mold and the sub master mold substrate (hereinafter also referred to as a resist residual film layer). This residual resist film layer may be an obstacle to formation of a fine pattern on the hard mask layer. Therefore, in order to remove the resist residual film layer, as described in Patent Document 2, ashing is performed on the resist residual film layer to remove the resist residual film layer.

JP 2005-345737 A JP-A-2005-50468

  In recent years, the dimensions of the fine patterns of the DTR media described above have been increasingly refined due to demands for improving performance. Specifically, the periodic structure of the fine pattern is densified to about 30 nm. On the other hand, according to the fine pattern forming method described in Patent Document 1, considerable labor is required to form a periodic structure smaller than 30 nm.

  An object of the present invention is to provide a sub-master mold having a fine pattern that is relatively simpler than the conventional one, which is made in consideration of the above-described circumstances.

According to a first aspect of the present invention, in the method for manufacturing a submaster mold from an imprint mold provided with grooves corresponding to a fine pattern, a hardmask layer is formed on the submaster mold substrate. It is characterized by having a fine pattern dimension changing step of performing dry etching using oxygen gas on the resist layer formed and formed on the hard mask layer and transferred with the fine pattern of the original mold.
According to a second aspect of the present invention, in the invention according to the first aspect, a hard mask layer including a conductive layer and an antioxidant layer on the sub-master mold substrate before the fine pattern dimension variation step. Forming a pattern forming resist layer on the hard mask layer, and transferring the fine pattern of the original mold to the resist layer by optical imprinting or thermal imprinting. Then, after the fine pattern dimension variation step, the hard mask layer is etched using the resist layer to which the fine pattern is transferred as a mask.
According to a third aspect of the present invention, in the invention according to the first or second aspect, the substrate is a translucent quartz substrate, and a light imprint is used for transferring a fine pattern to the resist layer. The resist layer is made of a photocurable resin, and chlorine gas is used for etching the hard mask layer.
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the hard mask layer includes a TaHf layer and a chromium nitride layer.

  ADVANTAGE OF THE INVENTION According to this invention, the submaster mold which has a fine pattern denser than before can be provided comparatively easily.

It is a section schematic diagram for explaining the manufacturing process of the submaster mold concerning this embodiment. It is a cross-sectional schematic diagram for demonstrating the manufacturing process of the submaster mold which has a base structure which concerns on another embodiment. It is a figure which shows the result observed using the scanning electron microscope about the submaster mold obtained by the Example and the comparative example, (a) is an Example, (b) is the surface of the submaster mold in a comparative example. It is a photograph shown.

The inventors of the present invention have studied various means for forming a fine pattern that is denser than the conventional one when producing a sub-master mold from an imprint master mold.
In the examination, the present inventors paid attention to the presence of the resist residual film layer. Then, rather than the resist residual film layer, dry etching using oxygen was performed on the resist layer itself to which the fine pattern was transferred. Then, in addition to the removal of the resist residual film layer, it has been found that the size of the fine pattern portion of the resist layer can be freely changed to a smaller one. As a result, it has been conceived that a fine pattern having a level of fineness that is difficult to achieve in the past can be obtained by a simple process of dry etching using oxygen gas.

<Embodiment 1>
Hereinafter, the form for implementing this invention is demonstrated based on FIG. 1 which shows the method of manufacturing the submaster mold 20 by the optical imprint which concerns on this embodiment.

First, as shown in FIG. 1A, a substrate 1 for a sub master mold 20 is prepared.
The substrate 1 may be a conventional substrate as long as it can be used as the sub-master mold 20. However, in the case of performing optical imprinting, the substrate 1 is preferably a transmissive substrate from the viewpoint of light irradiation to the transfer material. Examples of the transmissive substrate 1 include a glass substrate such as a quartz substrate.

Further, as for the shape of the substrate 1, it is preferably a disc shape. This is because the resist can be applied uniformly while rotating the disk substrate 1 when applying the resist. The shape may be other than a disk shape, and may be a rectangle, a polygon, or a semicircle.
In the present embodiment, description will be made using a disk-shaped quartz substrate 1.

  Next, as shown in FIG. 1B, the quartz substrate 1 is introduced into a sputtering apparatus. In the present embodiment, a target made of an alloy of tantalum (Ta) and hafnium (Hf) is sputtered with argon gas to form a conductive layer 2 made of tantalum-hafnium alloy, and a groove formed on the substrate 1 It is preferable to use the lower layer (conductive layer 2) of the hard mask layer 7 having a fine pattern corresponding to. The tantalum-hafnium alloy is preferable because it is a material that can be etched by a dry etching process using a chlorine-based gas, and the conductivity necessary to prevent charge-up when drawing an electron beam during mask manufacturing. Can be provided, and thereby the contrast at the time of alignment can be increased.

  The material of the conductive layer 2 may be a conductive material conventionally used as this type of conductive layer. As an example, a compound containing Ta as a main component as described above may be used. In this case, Ta compounds such as TaHf, TaZr, TaHfZr, and alloys thereof are suitable. On the other hand, at least one element of hafnium (Hf) and zirconium (Zr) or a compound thereof (for example, HfZr) can be selected, and these materials are used as base materials, for example, B, Ge, Nb, Si, C, etc. , N and other sub-materials can be selected. In the present embodiment, the conductive layer 2 made of a tantalum-hafnium (TaHf) alloy will be described.

  Next, in the present embodiment, from the viewpoint of preventing oxidation, the conductive layer 2 is not exposed to the atmosphere, and a chromium target is sputtered with a mixed gas of argon and nitrogen to form a chromium nitride layer 3. The upper layer (antioxidant layer 3 for conductive layer) in the hard mask layer 7 having a pattern is preferably used. The reason is as follows.

  By forming the chromium nitride layer 3 on the upper surface of the conductive layer 2, oxidation of the lower conductive layer 2 can be prevented. Specifically, the surface of the chromium nitride layer 3 is mainly oxidized in place of the conductive layer 2 made of a tantalum-hafnium alloy when exposed to the air after the hard mask layer 7 is formed and in the baking process in the resist coating process. Is done. When dry etching is performed with a chlorine-based gas in a state where the surface of the chromium nitride layer 3 is oxidized, a much higher etching rate can be obtained than when the surface of the conductive layer 2 is oxidized. In addition, even if cleaning is performed using ammonia water, perhydrosulfuric acid, or the like used in the removal of the resist layer 4 in the process of manufacturing the sub-master mold 20 from the mold 10 before removing the mask remaining hard mask layer, the chromium nitride layer 3 has sufficient resistance.

  As a material of the antioxidant layer 3, chromium nitride (CrN) is preferable as described above, but any other compound that can be used as the antioxidant layer may be used. For example, a molybdenum compound, chromium oxide (CrO), SiC, amorphous carbon, or Al may be used. In the present embodiment, the antioxidant layer 3 made of chromium nitride (CrN) will be described.

  Thus, as shown in FIG. 1B, a hard mask layer 7 having the tantalum-hafnium alloy layer 2 as a lower layer and the chromium nitride layer 3 as an upper layer is formed on the quartz substrate 1. The “hard mask layer” in the present embodiment is composed of a single layer or a plurality of layers, can protect a portion where a groove corresponding to a pattern is to be formed, and is used for etching a groove on a substrate. It is intended to refer to a layered product.

  After appropriately cleaning and baking the hard mask layer, as shown in FIG. 1C, a photo imprint resist is applied to the hard mask layer to form a resist layer 4. The mask blanks used for manufacturing the imprint sub-master mold 20 in this embodiment are prepared. Examples of the resist for photoimprinting include a photocurable resin, particularly an ultraviolet curable resin. Any photocurable resin may be used as long as it is suitable for an etching process performed later. In addition, it is preferable that this photocurable resin is liquid. As will be described later, when a master mold (or a sub-master mold to be a master mold, hereinafter referred to as a master mold 30) on which a fine pattern is formed is placed on a resist, it matches the fine pattern of the master mold 30. This is because the resist is easily deformed, and the fine pattern can be accurately transferred by subsequent exposure.

  In addition, the thickness of the resist layer 4 at this time is preferably such a thickness that the resist serving as a mask remains until the etching of the chromium nitride layer 3 is completed. This is because not only the chromium nitride layer 3 in this portion but also the resist layer 4 is removed in some cases when the portion of the substrate 1 where the groove is formed is removed.

  After the resist layer 4 is appropriately baked, an original mold 30 on which a fine pattern is formed is placed on the resist layer 4 as shown in FIG. At this time, if the resist layer 4 is liquid, it is only necessary to place the original mold 30. When the resist layer 4 is in a solid shape, the resist layer 4 may be soft enough to press the original mold 30 against the resist layer 4 and transfer a fine pattern.

Thereafter, the fine pattern of the original mold 30 is transferred to the resist layer 4 using a UV light irradiation device. At this time, the UV light exposure is usually performed from the master mold 30 side, but may be performed from the substrate 1 side when the mask blank substrate 1 is a translucent substrate. This fine pattern may be on the micron order, but may be on the nano order from the viewpoint of the performance of electronic devices in recent years, and this is preferable in view of the performance of the final product.

  At this time, in order to prevent a transfer failure due to a positional shift between the master mold 30 and the mask blank, preparation for providing an alignment mark groove on the substrate may be performed.

  After transferring the fine pattern, the original mold 30 is removed from the mask blanks as shown in FIG. Then, the resist remaining film layer 4a on the chromium nitride layer 3 is removed.

  At this time, in the present embodiment, dry etching using oxygen gas is performed not only on the resist residual film layer 4a but also on the entire resist layer 4. This dry etching not only removes the resist residual film layer 4a, but also removes the portion where the resist layer 4 is formed by etching as shown in FIGS. The dimension of becomes smaller. By reducing the size of the resist layer 4 at the stage of removing the resist residual film layer 4a, a convex portion having a smaller size can be provided on the substrate 1 of the sub master mold 20. In the future, a groove having a smaller width can be formed on the transfer destination medium.

  Specifically, the etching using oxygen gas is performed as follows. The substrate 1 having a resist pattern formed on the substrate is introduced into a dry etching apparatus. Then, dry etching is performed on the entire resist layer 4 in an oxygen gas atmosphere. As a result, the resist residual film layer 4a is removed, and at the same time, the size of the fine pattern of the resist layer 4 is further reduced. A rare gas (He, Ar, Xe, etc.) may be included as an additive gas to the oxygen gas.

  Thus, as shown in FIG. 1F, a resist pattern corresponding to a desired fine pattern is formed. A groove is formed on the substrate 1 in a portion where the resist is not formed.

(First dry etching)
Next, the substrate 1 having a resist pattern formed on the substrate is introduced into a dry etching apparatus. At this time, first dry etching with chlorine gas containing substantially no oxygen is performed to remove the conductive layer 2 and the antioxidant layer 3 in the portion where the resist layer 4 has been removed. At this time, dry etching may be performed while using a reducing gas such as BCl ₃ .

Thereby, as shown in FIG. 1G, a hard mask layer 7 having a fine pattern is formed. Note that the etching end point at this time is determined by using a reflection optical end point detector.
Note that “substantially no oxygen” means “not containing oxygen to the extent that the oxygen content in the etching apparatus is 5% or less”. In addition, performing dry etching using a gas that does not substantially contain oxygen is also simply referred to as dry etching.

(Second dry etching)
Subsequently, after evacuating the gas used in the first dry etching, the quartz substrate 1 is subjected to a second dry etching using a fluorine-based gas in the same dry etching apparatus. At this time, the quartz substrate 1 is etched using the hard mask layer 7 as a mask, and grooves corresponding to the fine pattern shown in FIG. Thereafter, the resist layer 4 is removed with an alkaline solution or an acid solution.

Examples of the fluorine-based gas used here include C _x F _y (for example, CF ₄ , C ₂ F ₆ , C ₃ F ₈ ), CHF ₃ , a mixed gas thereof, or a rare gas (He, Ar) as an additive gas thereto. ,
Xe and the like).

  Thus, as shown in FIG. 1 (h), groove processing corresponding to the fine pattern is performed on the quartz substrate 1, and the hard mask layer 7 having the fine pattern is formed on a portion other than the groove of the quartz substrate 1, thereby By removing the resist using an acid solution such as sulfuric acid, the mold 10 before removing the remaining hard mask layer for the sub-master mold 20 is produced.

(Third dry etching)
Next, a step of removing the hard mask layer 7 remaining on the mold 10 before removal of the remaining hard mask layer by dry etching with respect to the mold 10 before removal of the remaining hard mask layer thus manufactured (remaining hard mask layer removal step) ), Thereby producing the sub-master mold 20 shown in FIG.
The basic procedure of the third dry etching is the same as that of the first dry etching described above.

  After removing the hard mask layer 7 other than the groove forming portion through the third dry etching, the substrate 1 is cleaned if necessary. In this way, the sub master mold 20 is completed.

  In the present embodiment, the first to third dry etching is performed. However, the dry etching is separately performed according to the hard mask layer constituent materials other than the conductive layer and the antioxidant layer. It may be added during etching.

As shown in FIG. 2, if the sub-master mold 20 has a pedestal structure, the following steps may be performed after the formation of the mold 10 before removing the remaining hard mask layer and before the remaining hard mask layer removing step.
That is, the base structure resist 6 is applied on the mold 10 before removing the remaining hard mask layer in which the groove processing is performed on the quartz, and exposure and development with ultraviolet light are performed (FIG. 2A). Then, the mold 10 before removal of the remaining hard mask layer on which the resist pattern is formed is wet-etched with a mixed solution of hydrofluoric acid and ammonium fluoride, and the resist is removed by predetermined acid cleaning (FIG. 2 ( b)). In this way, the mold 10 before removing the remaining hard mask layer having the pedestal structure is manufactured (FIG. 2C), and the sub master mold 20 may be manufactured through the dry etching in which the reducing gas is introduced as described above. .

  By making the sub master mold 20 for imprinting into a pedestal structure as described above, the contact area between the sub master mold 20 and the medium onto which the pattern is transferred is reduced. Furthermore, a gap is formed between the sub master mold 20 and the transfer destination medium due to the pedestal structure. The release property between the sub master mold 20 and the transfer destination medium can be improved by the atmosphere entering the gap or by inserting a release assisting jig or the like from the gap.

  In the manufacturing method of the sub master mold 20 according to the present embodiment as described above, the following effects can be obtained. That is, by performing dry etching using oxygen on the resist layer itself to which the fine pattern has been transferred, the dimension of the fine pattern portion of the resist layer can be freely changed to a smaller one. As a result, a fine pattern having a level of fineness that is difficult to achieve in the prior art can be obtained relatively easily.

In the present embodiment, the dimensional variation of the fine pattern was performed in accordance with the step of removing the resist residual film layer generated due to the use of optical imprint. However, this embodiment is not limited to the case where the resist residual film layer is removed, but can also be used to change the dimension of the resist layer to which the fine pattern has been transferred. Specifically, the present invention can also be applied to a solid sheet-like resist layer in which no remaining film layer remains or a resist layer formed by thermal imprinting.
In this embodiment, the conductive layer and the antioxidant layer are provided. However, both of these layers are not provided, but only when a chromium compound layer is provided or when only the conductive layer is provided. However, the fine pattern dimension variation method in the resist layer as described above can be applied.

  Furthermore, such a sub master mold 20 can be used for thermal imprinting and optical imprinting, and can also be applied to nanoimprint technology. In particular, the present embodiment can be suitably applied to DTR media manufactured using imprint technology.

  As mentioned above, although embodiment which concerns on this invention was mentioned, said disclosure content shows exemplary embodiment of this invention. The scope of the present invention is not limited to the exemplary embodiments described above. Whether or not explicitly described or suggested herein, those skilled in the art will make various modifications to the embodiments of the present invention based on the disclosure of the present specification. Can be implemented.

Next, an Example is shown and this invention is demonstrated concretely. Of course, the present invention is not limited to the following examples.
<Example>
In this example, a disc-shaped synthetic quartz substrate (outer diameter 150 mm, thickness 0.7 mm) was used as the substrate 1 (FIG. 1A). This quartz substrate 1 was introduced into a sputtering apparatus. Then, a target made of an alloy of tantalum (Ta) and hafnium (Hf) (Ta: Hf = 80: 20 atomic ratio) is sputtered with argon gas to form a conductive layer 2 made of a tantalum-hafnium alloy having a thickness of 7 nm. (FIG. 1B).

  Thereafter, without exposing to the atmosphere, a chromium target was sputtered with a mixed gas of argon and nitrogen to form a chromium nitride layer 3 (chromium: nitrogen = 35: 65 atomic ratio) with a thickness of 2.5 nm. Thus, on the hard mask layer 7 having the tantalum-hafnium alloy layer 2 and the chromium nitride layer 3, a photo-curing resin resist film 4 (PAK-01 manufactured by Toyo Gosei Co., Ltd.) is applied to a thickness of 45 nm by spin coating, Bake treatment was performed (FIG. 1 (c)).

Next, the master mold 30 provided with a line-and-space pattern having a periodic structure with a line of 30 nm and a space of 60 nm was placed on the photocurable resist layer 4 and subjected to ultraviolet exposure (FIG. 1D). Thereafter, the resist layer 4 was developed, and the fine pattern was transferred to the resist layer 4 (FIG. 1E). Thereafter, dry etching (O ₂ : Ar = 1: 3 (flow rate ratio)) with oxygen gas and argon was performed on the resist layer 4 on the chromium oxide layer 3. As a result, the resist remaining film layer 4a was removed, and the fine pattern size of the resist layer was reduced to form a desired resist pattern (FIG. 1 (f)).

Next, the substrate 1 on which the hard mask layer 7 having a resist pattern is formed is introduced into a dry etching apparatus, and dry etching (BCl substantially free of oxygen) is introduced while simultaneously introducing BCl ₃ gas and Cl ₂ gas. ₃ : Cl ₂ = 1: 5 (flow rate ratio)). Then, a hard mask layer 7 having a fine pattern made of a laminate of a tantalum-hafnium alloy film (conductive layer 2) and a chromium nitride layer 3 was formed (FIG. 1 (g)).

Subsequently, after evacuating the gas used for dry etching on the hard mask layer 7, dry etching using a fluorine-based gas (CHF ₃ : Ar = 1: 9 (volume ratio)) in the same dry etching apparatus. Was performed on the quartz substrate 1. At this time, the quartz substrate 1 was etched using the hard mask layer 7 as a mask, and grooves corresponding to the fine pattern were formed on the substrate as shown in FIG.

  At this time, the etching time was adjusted so that the groove depth of the substrate 1 was 70 nm. Specifically, etching was performed for 230 seconds. Here, in order to confirm the cross-sectional shape of the pattern, the evaluation blanks produced in the same manner as above were broken and the cross-section of the pattern was observed with a scanning electron microscope. As a result, the resist pattern disappeared and the surface of the chromium nitride layer 3 Was exposed. The film thickness of the chromium nitride layer 3 was reduced to about 1 nm with respect to 2.5 nm before the etching, but the groove width of the quartz substrate 1 is different from that of the tantalum-hafnium alloy layer 2 and the chromium nitride layer 3. It was confirmed that the width of the fine pattern composed of the hard mask layer 7 having the same is almost the same as that of the fine pattern and that the groove depth of the quartz substrate 1 is uniform.

  Then, the resist layer 4 is removed using perhydrosulfuric acid (concentrated sulfuric acid: hydrogen peroxide solution = 2: 1 (volume ratio)) composed of concentrated sulfuric acid and hydrogen peroxide solution, and the sub-master mold 20 in this embodiment is removed. A mold 10 for removing the remaining hard mask layer for manufacturing was obtained (FIG. 1 (h)).

After that, after vacuum evacuation, dry etching substantially free of oxygen (BCl ₃ : Cl ₂ =) while simultaneously introducing BCl ₃ gas and Cl ₂ gas into the mold 10 before removing the remaining hard mask layer. 1: 4 (flow rate ratio)). And the submaster mold 20 in a present Example which removed the hard mask layer 7 on a board | substrate was produced (FIG.1 (i)).

<Comparative example>
In order to compare with the above-described embodiment, dry etching was not performed on the resist residual film layer 4a in the comparative example. Otherwise, a sub-master mold for imprinting was produced in the same manner as in the example.

<Evaluation>
The imprint sub-master mold 20 obtained in the examples and comparative examples was observed using a scanning electron microscope. The result is shown in FIG. FIG. 3A is an example, and FIG. 3B is a photograph showing the surface of a sub-master mold for imprinting in a comparative example.

  In the example shown in FIG. 3A, a fine fine pattern could be formed as compared with the comparative example shown in FIG.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Conductive layer 3 Antioxidation layer 4 Resist layer 4a for fine pattern formation Resist residual film layer 10 Residual hard mask layer mold before removal 20 Submaster mold 30 Original mold 6 Resist layer for base structure

Claims (4)

In a method of manufacturing a sub master mold from an original mold for imprint provided with a groove corresponding to a fine pattern,
A hard mask layer is formed on the substrate for the sub-master mold, and dry etching using oxygen gas is performed on the resist layer formed on the hard mask layer and transferred with the fine pattern of the original mold. A method for producing a sub-master mold, comprising the step of changing a fine pattern dimension. Before the fine pattern dimension variation step,
Forming a hard mask layer including a conductive layer and an antioxidant layer on the substrate for the sub master mold, and forming a resist layer for pattern formation on the hard mask layer;
And transferring the fine pattern of the original mold to the resist layer by optical imprinting or thermal imprinting,
After the fine pattern dimension variation step,
2. The method of manufacturing a sub-master mold according to claim 1, further comprising: etching the hard mask layer and the substrate using the resist layer to which the fine pattern is transferred as a mask. The substrate is a translucent quartz substrate;
Photo imprint is used for fine pattern transfer in the resist layer for pattern formation,
The resist layer for pattern formation is made of a photocurable resin,
The method for manufacturing a sub-master mold according to claim 1, wherein chlorine gas is used for etching the hard mask layer.   4. The method of manufacturing a sub master mold according to claim 1, wherein the hard mask layer includes a TaHf layer and a chromium nitride layer.