JP2012148447A - Method for manufacturing board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a time for forming an alignment mark while detecting the alignment mark by light, in manufacturing a board formed with the alignment mark.SOLUTION: The method for manufacturing the board in forming the alignment mark on the board includes: a process for forming a resist layer so as to cover the board; an exposure process by radiating the resist layer with an energy beam to draw or expose a prescribed pattern; a resist pattern forming process for developing the drawn or exposed resist layer to form a resist pattern formed of projections and recesses; and an alignment mark forming process for forming, on the board, the alignment mark which is larger than the recessed part in the resist pattern in part and is large enough to be detected by light by subjecting at least part of the board in a portion having the resist pattern to wet etching after the formation of the resist pattern.

Description

  The present invention relates to a substrate manufacturing method suitable for use in, for example, an imprint technique.

  An imprint technique using a photolithography method is known (see, for example, Patent Document 1). This imprint technique is a technique for transferring an uneven pattern using an original substrate and a substrate to be transferred.

  In the technique described in Patent Document 1, a concavo-convex pattern is formed in advance on one main surface of an original substrate, while a resist layer is formed on one main surface of a transferred substrate. Then, in a state where the substrate to be transferred is heated and the resist layer is softened, the resist layer is deformed by bringing the uneven pattern of the original substrate into contact with the resist layer of the substrate to be transferred and pressing. Further, in this state, the transferred substrate is cooled or exposed to cure the resist layer. Then, a pattern having a shape in which the concave / convex relationship of the concave / convex pattern of the original substrate is reversed is transferred (formed) to the resist layer of the transferred substrate.

  Such imprint technology uses, for example, a master substrate called a sub-master mold to produce a recording medium for hard disk use, or uses a master substrate called a master mold to perform the above-mentioned sub master mold. It is used for manufacturing.

  The master mold mentioned here is manufactured using a glass substrate having optical transparency as a material. The master mold is provided with a mark for alignment (hereinafter also referred to as “alignment mark”). This alignment mark is used when, for example, the relative positioning of the master mold and the substrate to be transferred, or when the recording medium is manufactured using a sub-master mold manufactured using the substrate to be transferred as a material. Used for alignment with.

  Said alignment mark is attached | subjected at the process of producing a master mold. For this reason, in a series of production steps of the master mold, there is a step for forming an alignment mark on the glass substrate as the material (hereinafter referred to as “alignment mark forming step”).

The alignment marks mentioned here are also provided on the transfer substrate. When the sub-master mold is manufactured using the transfer substrate as a material, the positions of both alignment marks are detected and measured by an optical sensor or the like. Then, the master mold and the transfer substrate are brought into contact with each other so that the positions of the alignment marks of the two coincide.
By doing so, it is possible to improve the accuracy of the pattern position and the like when producing the sub master mold from the transfer substrate, and consequently the accuracy of the product produced by the sub master mold.

JP 2009-206339 A

However, the conventional master mold manufacturing process has the following problems.
In recent years, in a master mold, a pattern of a portion corresponding to a data portion in terms of a recording medium has become nano-order.

  On the other hand, when the detection method of the alignment mark is light, if the alignment mark is miniaturized to a size equal to or smaller than the wavelength of the light, detection becomes extremely difficult. Therefore, in order to maintain the accuracy of position detection, the size of the alignment mark is in the micron order. In other words, there is a difference of about 1000 times in size between the pattern corresponding to the data part and the alignment mark, and a pattern from the nano order to the micron order is created on one substrate. Must-have.

Originally, it is only necessary to form both with a separate electron beam drawing device, but when drawing with a separate electron beam drawing device, the position of the master mold is transferred from one device to another. There is a possibility that a shift occurs, and the alignment mark itself for accurate positioning is shifted and formed.
Further, the electron beam drawing apparatus is expensive, and it is expensive to purchase a new electron beam drawing apparatus only for forming the alignment mark.
For this reason, a pattern and an alignment mark corresponding to the data portion are usually drawn by one electron beam drawing apparatus.

  On the other hand, as described above, there is an order difference of about 1000 times between the pattern of the portion corresponding to the data portion and the alignment mark. Therefore, while drawing the pattern of the data portion with the beam diameter in the electron beam lithography system as nano-order, in the alignment mark, the drawing position is shifted little by little with respect to the resist in the alignment mark portion without changing the beam diameter and output. However, by performing overwriting, a drawing portion of micron order is formed.

  However, with such a drawing method, it takes a few days just to draw the alignment mark portion, and the work efficiency cannot be said to be good.

  On the other hand, if the beam diameter or output is changed, it takes several days for the beam diameter or output to reach a constant state. It takes time.

  As a result, a lot of days are required only for the production of the alignment mark in the master mold, and it cannot be said that the working efficiency in producing the master mold is good. As a result, the production efficiency of the sub-master mold is reduced, and a considerable amount of time is required for producing the final product.

  A main object of the present invention is to provide a technique capable of shortening the time for forming an alignment mark while making it possible to detect the alignment mark by light when producing a substrate on which the alignment mark is formed.

The first aspect of the present invention is:
In the substrate manufacturing method when forming alignment marks on the substrate,
Forming a resist layer so as to cover the substrate;
In the substrate manufacturing method when forming alignment marks on the substrate,
Forming a resist layer so as to cover the substrate;
An exposure step of drawing or exposing a predetermined pattern by irradiating the resist layer with an energy beam;
Developing the drawn or exposed resist layer, and forming a resist pattern comprising irregularities; and a resist pattern forming step,
After the resist pattern forming step, wet etching is performed on at least a part of the substrate in the part having the resist pattern, and the size is larger than the concave part of the resist pattern in the part and is detectable using light. An alignment mark forming step of forming an alignment mark on the substrate,
It is a board | substrate preparation method characterized by having.
The second aspect of the present invention is:
The substrate has a mark portion where the alignment mark is formed, and a non-mark portion where a concave-convex pattern is formed in other portions,
The first aspect is characterized in that the beam diameter and output of the energy beam are substantially the same when forming a resist pattern in the mark portion and forming a resist pattern in the non-mark portion. It is the board | substrate preparation method of description.
The third aspect of the present invention is:
After forming the hard mask layer so as to cover the substrate, the resist layer is formed so as to cover the hard mask layer,
The first or second aspect is characterized in that after the resist pattern forming step and before the alignment mark forming step, an etching step is performed on the hard mask layer to transfer the resist pattern to the hard mask layer. It is the board | substrate preparation method of description.
The fourth aspect of the present invention is:
After the etching process for the hard mask layer and before the alignment mark forming process, the mark portion and the non-mark portion of the substrate are dry-etched, and the concave / convex pattern of the hard mask is changed to the mark portion and the non-mark portion. It is a board | substrate preparation method as described in a 3rd aspect characterized by transferring to a part.
According to a fifth aspect of the present invention,
The substrate manufacturing method according to the fourth aspect, wherein a protective resist layer is provided on the substrate in order to protect the uneven pattern of the non-mark part before the alignment mark forming step.
The sixth aspect of the present invention is:
A plurality of concave portions of the resist pattern are provided at equal intervals in a linear shape when viewed from the plane,
In the alignment mark forming step, at least one linear alignment mark is formed from a plurality of linear recesses in the resist pattern by overlapping a region to be cut by wet etching between adjacent recesses. The substrate manufacturing method according to any one of the first to fifth aspects, wherein the substrate is formed on the substrate.
The seventh aspect of the present invention is
While the irradiation of the energy beam is an electron beam drawing having a nano-order beam diameter,
7. The substrate manufacturing method according to any one of the first to sixth aspects, wherein the alignment mark is formed in a submicron order or a micron order.
The eighth aspect of the present invention is
The substrate is a disk-shaped quartz substrate for forming an original mold in imprinting,
The substrate has a mark portion in which the alignment mark is formed in the central portion of the substrate, while the other portion has a non-mark portion in which an uneven pattern is formed in the peripheral portion of the substrate,
The substrate alignment method according to any one of the first to seventh aspects, wherein the alignment mark is used for alignment when transferring a predetermined concavo-convex pattern of the master mold to a transfer object. is there.
The ninth aspect of the present invention provides
When forming an alignment mark used for alignment when transferring a predetermined concave-convex pattern of the master mold to a transfer object on a disc-shaped quartz substrate for forming the master mold in imprinting In the substrate manufacturing method of
The substrate has a mark portion in which the alignment mark is formed in the central portion of the substrate, while the other portion has a non-mark portion in which a concavo-convex pattern is formed in the peripheral portion of the substrate,
Forming a hard mask layer so as to cover the substrate, and then forming a resist layer so as to cover the hard mask layer;
A step of performing electron beam drawing with a nano-order beam diameter on the resist layer;
The drawn resist layer is developed to form a resist pattern composed of a plurality of equidistant line-shaped irregularities when viewed from a plane in the mark portion, while in the non-mark portion, Forming a resist pattern composed of irregularities of the order;
Etching the hard mask layer and transferring the resist pattern to the hard mask layer;
Performing dry etching on the mark portion and the non-mark portion in the substrate, and transferring the concave / convex pattern of the hard mask to the mark portion and the non-mark portion;
Providing a protective resist layer so as to cover the non-marked portion in order to protect the uneven pattern transferred to the non-marked portion;
After providing the protective resist layer, wet etching is performed on the mark portion, and by overlapping the regions to be cut by wet etching between adjacent recesses, from a plurality of linear recesses in the resist pattern, Forming at least one linear alignment mark of submicron order or micron order on the mark part;
Have
When forming a resist pattern in the mark portion and forming a resist pattern in the non-mark portion, the beam diameter and output in the electron beam drawing are substantially the same, This is a substrate manufacturing method.
According to a tenth aspect of the present invention, in the substrate forming method according to the second or ninth aspect, the non-marked portion is a data portion that is a source of data of a magnetic recording medium.

  According to the present invention, when producing a substrate on which an alignment mark is formed, it is possible to detect the alignment mark by light and reduce the time for forming the alignment mark.

It is the schematic explaining the master mold concerning an embodiment of the invention. FIG. 2 is a schematic cross-sectional view taken along line A-A ′ of FIG. 1, and is a schematic process flow diagram of a substrate manufacturing method according to an embodiment of the present invention. It is a process flow schematic diagram of a substrate fabrication method concerning another embodiment of the present invention. (A) It is the schematic explaining the master mold which concerns on another embodiment of this invention. (B) In the board | substrate preparation method which concerns on another embodiment of this invention, it is a figure which shows the case where a protective resist layer is used as the weir in the case of wet etching. (C) It is a figure which shows the board | substrate after providing a dam like (b) and performing wet etching.

The present inventors have studied various means for shortening the time for forming alignment marks.
In the study, the inventors focused on how to fill in the difference between the beam diameter size and the alignment mark size.

  The inventors have obtained the knowledge that the over-etching, which was conventionally considered as a variation factor of the pattern size, is used as a means for enlarging the size of the concave portion of the concave-convex pattern. In order to generate this over-etching, it has been conceived that wet etching is used in the alignment mark forming step.

<Embodiment 1>
Hereinafter, embodiments of the present invention will be described.
As an order, first, the process of forming the alignment mark 5 on the master mold 10 as shown in FIG. In this description, FIG. 2 which is a schematic diagram of the AA ′ cross section of the master mold 10 of FIG. 1 is used.
Thereafter, in <Embodiment 2>, a method for detecting the alignment mark 5 formed in Embodiment 1 will be described.
In <Embodiment 3>, various modifications will be described.

A substrate manufacturing method according to an embodiment of the present invention includes a plurality of steps described below.
1. 1. Hard mask layer forming process 2. Resist layer forming step 3. Electron beam drawing process Development process 5. 5. Hard mask etching process 6. Substrate etching process Step of forming protective resist layer 8. Alignment mark formation process by wet etching (pattern recess enlargement process)
9. 9. Step of removing resist layer and protective resist layer Hard Mask Removal Step Finally, the effect of this embodiment will be described.
Hereafter, each said process is demonstrated in order.

[1. Hard mask layer formation process]
First, as shown in FIG. 2A, a substrate 1 that is a material (original) of the master mold 10 is prepared, and a hard mask layer 2 is formed on the main surface of the substrate 1. In the present embodiment, a circular quartz substrate (glass substrate) having optical transparency is used as the substrate 1.
As the hard mask layer 2, for example, a single metal layer made of chromium or a single metal layer (alloy layer) containing chromium is formed.

[2. Resist layer forming step]
Next, a resist layer 3 is formed on the main surface of the substrate 1 so as to cover the hard mask layer 2. The resist layer 3 is used to form an etching mask to which the resist pattern 3a is transferred in a “hard mask etching process” to be described later. In the present embodiment, the resist layer 3 is formed using a positive resist by a spin coating method or the like.

[3. Electron beam drawing process]
Next, the substrate 1 is set in an electron beam drawing apparatus (not shown). At this time, an electron beam generator (not shown) is disposed on the main surface side of the substrate 1 and the electron beam 9 is irradiated on the resist layer 3 on the substrate 1 so that the irradiation region has a predetermined shape. (Hereinafter, the irradiation of the electron beam 9 is also referred to as electron beam drawing).

  In the present embodiment, the resist layer 3 is formed of a positive resist. For this reason, a part (exposed part) of the resist layer 3 irradiated with the electron beam 9 is solubilized. That is, when viewed from the plane, if the region irradiated with the electron beam 9 has a linear shape, the concave portion in the resist pattern 3a also has a linear shape.

  When the electron beam 9 is irradiated, a portion on the substrate 1 where the alignment mark 5 is to be formed (hereinafter, also referred to as a mark portion 8) and a non-mark on which the concavo-convex pattern is formed at other portions. Electron beam drawing is performed on both parts in this process. In the present embodiment, the non-marked portion is a portion where a concavo-convex pattern serving as a source of data of a magnetic recording medium manufactured by the master mold 10 is to be formed (hereinafter also referred to as a data portion 7).

As a specific drawing shape, a plurality of equally-spaced line shapes are drawn in the mark portion 8. This interval is preferably set so that regions that are over-etched by wet etching, which will be described later, overlap in adjacent openings.
On the other hand, the data portion 7 is drawn so as to have a predetermined pattern shape.

At this time, it is preferable that the beam diameter and the output of the energy beam are substantially the same when the resist pattern 3a in the mark portion 8 is formed and when the resist pattern in the data portion 7 is formed. This is because, if the beam diameter or output is not changed, the beam diameter or output is kept constant, and it is not necessary to take time to adjust the electron beam drawing apparatus.
Note that “substantially the same beam diameter and output” includes those in which the beam diameter and output settings in the apparatus are the same, while the numerical values vary in error even though the settings are the same. Including the case of doing.
In the present embodiment, as the predetermined pattern in the data portion 7 is set to the nano order, the beam diameter is also set to the nano order (for example, about 10 nm, specifically, more than 0 nm and less than 0.1 μm). The alignment mark 5 that is formed automatically is of the order of submicron or micron.

  The “submicron order” in the present embodiment refers to an order of a size of more than 0.1 μm and less than 1 μm. The “micron order” means an order of a size of 1 μm or more and 10 μm or less. The width of the alignment mark 5 is defined by the dimension in the short direction of the mark if the shape of the alignment mark 5 in plan view is a rectangle, a cross shape, an arc shape, or the like.

In addition, the “predetermined pattern shape” is drawn in the present embodiment, specifically, the pattern shape that is the source of data on the recording medium is drawn at the peripheral portion (data portion 7) of the circular substrate. This pattern shape may be arbitrary, and the shape of DTR media (Discrete Track Media: linear in plan view), the shape of BPM (Bit Patterned Media: dot in plan view), and It may be a mixed shape.
On the other hand, in the central part (mark part 8) of the circular substrate, a plurality of line shapes are drawn at equal intervals when viewed from the plane. In addition, a plurality of line shape drawing in the mark portion 8 will be a source of one thick line shape alignment mark 5 in the future.

[4. Development process]
Next, as shown in FIG. 2B, a part of the resist layer 3 on which the pattern shape has been drawn in the first electron beam drawing step is removed by development to form a resist pattern 3a. In this case, the other part of the resist layer 3 that has not been irradiated with the electron beam 9 in the electron beam drawing process remains as a resist pattern 3a after development. The resist pattern 3a includes an opening H 'corresponding to a part of the shape of the alignment mark 5 described later in addition to the opening H corresponding to a predetermined pattern shape in the data portion 7. Become.

[5. Hard mask etching process]
Next, as shown in FIG. 2C, the hard mask layer 2 is etched with a chromium etching solution using the resist pattern 3a as a mask. Thereby, a part of the hard mask layer 2 is etched with the same planar shape as the resist pattern 3a. After this etching, the other part (the part that has not been etched) of the hard mask layer 2 remains as the hard mask 2a, and the resist pattern 3a is laminated on the hard mask 2a.

Further, when the hard mask layer 2 is etched, the above-described openings H and H ′ are dug down according to the thickness of the hard mask layer 2.
Here, the opening shape of the opening H of the hard mask 2a obtained by etching in the data portion 7 corresponds to the shape of the recess of the predetermined uneven pattern.
On the other hand, the opening shape of the opening H ′ of the hard mask 2 a obtained by etching in the mark portion 8 corresponds to a part of the alignment mark 5. This is because the opening shape of the hard mask 2a is enlarged by wet etching described later (reference numeral 5 in FIG. 1 (f)) and transferred to the mark portion 8 of the substrate 1 (FIG. 1 (g)). .

  As described above, in the mark portion 8, a resist pattern 3 a composed of a plurality of evenly spaced linear irregularities is formed, while in the data portion 7, a resist pattern 3 a composed of nano-order irregularities is formed. Form.

[6. Substrate etching process]
Next, as shown in FIG. 2D, it is preferable to dry-etch the substrate 1 using the resist pattern 3a and the hard mask 2a. This is because by using dry etching, the opening shape of the hard mask 2 a can be precisely transferred to the substrate 1, and a precise uneven pattern can be formed in the data portion 7.
Thereby, a part of the alignment mark 5 is formed on the main surface of the substrate 1. That is, only a part of the alignment mark 5 may be formed on the substrate 1 in advance.
By doing so, it is possible to etch the alignment mark 5 quickly and surely into a completed shape rather than performing wet etching from a state where the substrate 1 is not etched at all.

  A part of the alignment mark 5 is formed in a concave shape in a cross section by digging up the opening H ′ described above. For this reason, a part of the alignment mark 5 follows the opening shape of the opening H ′.

  Further, in the data portion 7 on the main surface of the substrate 1, the portion corresponding to the opening H where the hard mask 2 a and the resist pattern 3 a are not stacked is etched simultaneously with the formation of a part of the alignment mark 5. . For this reason, a predetermined concavo-convex pattern in the data portion 7 is formed around the main surface of the substrate 1.

[7. Protective resist layer forming step]
Next, as shown in FIG. 2E, a protective resist layer 6 is provided so as to cover the data portion 7. After this step, a step of enlarging the shape of the opening H ′ of the hard mask on the mark portion 8 of the substrate by wet etching and transferring it onto the substrate is refrained. If no allowance is given, not only the opening H ′ but also the data portion 7 requiring a fine pattern shape is wet etched by this wet etching. Therefore, in this embodiment, this protective resist layer 6 is provided in order to protect the concavo-convex pattern transferred to the data portion 7.
In the present embodiment, the same resist as the resist layer 3 is used and is formed by the same spin coat method or the like so that it can be removed together in a subsequent resist pattern removing step. Of course, other types of resists may be used as long as they can be finally peeled off without pattern distortion.

[8. Alignment mark forming step by wet etching (step of further enlarging the concave portion of the resist pattern in the mark portion)]
As described above, only the opening H ′ of the order of nanometers is provided on the mark portion 8 in the hard mask. On the other hand, the size of the alignment mark 5 that can be detected using light needs to be on the order of submicron or micron.
Therefore, in the present embodiment, wet etching is performed on the mark portion 8 of the substrate 1 from above the hard mask having the opening H ′ on the order of nanometers. For this wet etching, when the substrate 1 is a quartz substrate, wet etching with hydrofluoric acid may be used.

By this wet etching, as shown in FIG. 2F, over-etching occurs in the mark portion 8 of the substrate 1. As a result, the shape of the nano-order linear opening H ′ is enlarged and transferred to the substrate 1.
By doing so, the alignment mark 5 enlarged to at least the submicron order can be formed on the substrate 1.

Furthermore, in the present embodiment, a plurality of equally-spaced line shapes are drawn in the mark portion 8. In the mark portion 8 of the substrate 1, the interval is set so that the region that is over-etched by the wet etching described above overlaps between adjacent openings.
By doing so, one submicron order or micron order one that can be detected by using visible light frequently used in light by wet etching despite the formation of the nano-order resist pattern 3a. At least one of the linear alignment marks 5 can be formed on the mark portion 8.

  Note that the depth of the alignment mark 5 may be set according to the etching amount of the substrate 1. For example, it may be formed with a depth of 0.1 μm.

[9. Resist pattern and protective resist layer removal step]
Next, the resist pattern 3 a and the protective resist layer 6 are removed from the first main surface of the substrate 1. The removal of the resist pattern 3a and the protective resist layer 6 is performed with, for example, a resist stripping solution.

[10. Hard mask removal process]
Next, the hard mask 2 a is removed from the first main surface of the substrate 1. The removal of the hard mask 2a is performed by, for example, a chromium etching solution.

  2G, a substrate (master mold 10) having the alignment mark 5 in the mark portion 8 and the predetermined uneven pattern in the data portion 7 on the main surface side is obtained.

[Effect of the embodiment]
In the substrate manufacturing method according to the embodiment of the present invention, the following effects can be obtained.
That is, electron beam drawing is performed on the substrate on the resist layer provided on the data portion 7 having a nano-order pattern and the mark portion on which the micro-order alignment mark is formed. At this time, even if there is a difference in order between the pattern of the data portion and the alignment mark, these can be formed by the same apparatus without changing the beam diameter or the output setting.

  Then, overetching, which was conventionally considered as a variation factor of the pattern size, is reversely used in the present embodiment as means for expanding the size of the concave portion of the concave / convex pattern. In order to generate this overetching, the size of the recess can be enlarged and transferred to the substrate by using wet etching in the alignment mark forming step. As a result, in the electron beam drawing, an alignment mark having a size that can be detected by light can be formed in a shorter drawing time (that is, a smaller irradiation area) than conventional.

  As a result, the time for forming the alignment mark can be shortened. That is, it does not take many days only for the production of the alignment mark in the master mold, the work efficiency in producing the master mold is improved, and the production efficiency of the sub master mold is also improved. As a result, the production efficiency of the final product is also improved.

<Embodiment 2>
In the present embodiment, a method for detecting the alignment mark 5 formed in the first embodiment will be described.

  As described above, in the present embodiment, it is necessary to form the alignment mark 5 having a detectable size using light.

  A laser may be used as the light source of this light, or light sources having a single wavelength and a plurality of wavelengths may be used. Further, the wavelength is not particularly limited, but the wavelength of visible light is preferable from the viewpoint of ease of use.

  When using visible light, the alignment mark 5 cannot be detected unless the size of the alignment mark 5 has the same size as the wavelength of visible light. Therefore, wet etching is performed as described above so that the size of the alignment mark 5 is approximately the same as the wavelength of visible light.

  Further, as a method for detecting the alignment mark 5, for example, a sensor for measuring the position of the master mold 10 may be mounted on an XY stage that can move in the XY directions. With this sensor, the position of the alignment mark 5 formed on the master mold 10 is measured, and the relative position between the position of the XY stage and the mold is measured. The measuring means may use a pattern recognition device that uses a method of calculating the position by taking a video image of a mark with an optical system such as a microscope or a CCD, performing image processing, or a method using heterodyne interference.

  Further, the sensor may have a function of measuring the distance in the Z-axis direction, and may measure the distance between the lower surface of the mold and the sensor in synchronization with the movement of the XY stage. The detection method at this time may be a method of emitting a laser beam and detecting a position of reflected light, a method using a change in capacitance, or the like.

An outline of a specific method for aligning the master mold 10 of the first embodiment and the transfer substrate using the above detection method is as follows.
That is, the transfer surface of the transfer substrate and the transfer surface on which the concave / convex pattern of the master mold 10 is formed are arranged to face each other. At this time, a gap between them is filled with a resist solution that becomes the resist layer 3. Then, two alignment marks 5 (marks provided on the transfer surface and the master mold 10) are formed from above the transfer surface and the master mold 10 by an alignment optical system having an optical axis perpendicular to the transfer surface. The master mold 10 and the transferred substrate are aligned using the reading result.

<Embodiment 3>
The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications and improvements as long as the specific effects obtained by the constituent elements of the invention and combinations thereof can be derived.
Therefore, in this embodiment, various modifications in Embodiment 1 are shown. The points not particularly noted are the same as in the first embodiment.

First, the shape of the substrate 1 may be other than a circle. For example, a polygonal substrate including a square or the like may be used.
The type of the substrate 1 may be made of quartz, sapphire, or a metal such as Si, plastic, ceramic, or the like, or a combination thereof. It doesn't matter.

  Moreover, in the said embodiment, although the hard mask layer 2 shall be formed with the metal layer which consists of chromium, or the metal layer (alloy layer) containing chromium, not only this but the hard mask layer 2 You may form by the metal layer (an alloy layer is included) which does not contain chromium.

  For example, in the above-described embodiment, the resist layer 3 is formed using a positive resist. However, the present invention is not limited to this, and the resist layer 3 may be formed using a negative resist.

In the first embodiment, the hard mask layer 2 and the resist layer 3 are provided on the substrate, but an adhesion layer may be separately provided between the two layers.
Further, in the case where the groove can be formed by etching the substrate 1 using the resist pattern 3a as a mask material without requiring the hard mask layer 2, the resist layer 3 may be formed directly on the substrate 1. In this case, the resist layer 3 may be provided on the substrate 1 after the dehydration baking process or the formation of the adhesion auxiliary layer.

  In the first embodiment, the mark portion 8 is set to be the central portion of the substrate and the data portion 7 on which the concave / convex pattern from which data is formed is formed to be the peripheral portion of the substrate. That is, the mark portion 8 may be disposed at the peripheral portion of the substrate and the data portion 7 may be disposed at the central portion of the substrate. The mark portion 8 may be provided in the peripheral portion of the substrate and the central portion of the substrate, and the data portion 7 may be disposed therebetween. Further, the arrangement of the mark portion 8 and the data portion 7 is not limited to the above example as long as the concave / convex pattern of the data portion 7 is not finally taken.

  In the first embodiment, [3. [Electron beam drawing step] describes electron beam drawing as the name suggests. On the other hand, the present invention is not limited to electron beam drawing, but can be applied to irradiation of other energy beams. Specifically, ultraviolet rays, X-rays, electron beams, ion beams, proton beams, or the like may be used. After all, any method that can apply a predetermined pattern shape to the resist layer 3 may be used. Therefore, exposure using an exposure mask may be performed on the resist layer 3 instead of drawing as in the first embodiment. If exposure is to be performed, it is preferable that the substrate 1 be light transmissive in terms of enabling backside exposure.

  Also, [3. In the electron beam drawing step], instead of forming the resist pattern 3a of the data portion 7 and the mark portion 8 as in the first embodiment, the resist pattern 3a of the mark portion 8 is formed, and then the resist pattern of the data portion 7 is formed. 3a may be formed separately. By doing so, it is not necessary to worry about the concavo-convex pattern of the data portion 7 when forming the alignment mark.

  In the first embodiment, [5. In the hard mask etching step], wet etching is performed. Instead, dry etching may be performed using a gas corresponding to the material constituting the hard mask layer 2.

  Further, in the first embodiment, [6. The alignment mark 5 is formed after the substrate etching step], but this order may be reversed. That is, as shown in FIG. Until the alignment mark forming step by wet etching], the protective resist layer 6 is provided on the data portion 7 without etching the substrate 1 (FIG. 3E). Then, after the alignment mark 5 is formed and the protective resist layer 6 is removed, an uneven pattern of the data portion 7 may be separately formed on the data portion 7 (FIG. 3F).

  In the first embodiment, [7. In the protective resist layer forming step], the protective resist layer 6 is provided so as to cover the data portion 7. On the other hand, as shown in FIGS. 4A and 4B, a protective resist layer 11 serving as a weir may be formed between the data portion 7 and the mark portion 8. By surrounding the mark portion 8 of the disk-shaped substrate 1 with a weir made of a protective resist layer 11 (FIG. 4B), at least a part of the substrate in the portion having the resist pattern 3a (that is, only the mark portion 8) is formed. Wet etching can be performed (FIG. 4C).

  In the first place, the data portion 7 requires a precise uneven pattern. This concavo-convex pattern may be drowned even with a slight impact, and the possibility that the concavo-convex pattern may be drowned as the protective resist layer 6 is peeled off cannot be denied.

  However, by forming the protective resist layer 11 serving as a dam as described above, the opportunity for the protective resist layer 11 serving as a dam to enter the concavo-convex pattern in the data portion 7 can be eliminated, and a process of peeling off the protective resist layer. Need not be applied to the data portion 7, and the opportunity for deformation of the concavo-convex pattern can be eliminated.

  In the first embodiment, [8. In the alignment mark forming step by wet etching], the resist pattern 3a, which is the basis of the alignment mark 5, is formed into a pattern made of a plurality of equally spaced linear irregularities. On the other hand, the recess may be other than a linear shape, may be a bit shape, or may be a rectangular shape. After all, it is only necessary that the alignment mark 5 has a size that can be detected using light after wet etching.

Further, instead of providing only one linear alignment mark 5 as described above, a plurality of alignment marks 5 may be provided. At this time, each alignment mark 5 only needs to have a size that can be detected using light. Further, the plurality of alignment marks 5 may be periodic recesses.
By doing so, in the case of performing detection using light energy periodic fluctuation at the time of detection by light, a change occurs only in a portion where the alignment mark 5 exists in the periodic fluctuation. By utilizing this, it is considered that light can be detected even with an alignment mark of sub-micron order or even lower order, without forming a single micro-order alignment mark.

Further, the electron beam drawing region may be set as one line having a width smaller than the submicron order, and one alignment mark 5 may be formed from the one line.
Further, the number of alignment marks may be provided as shown in FIG. 1 or only one. A plurality of concentric circles may be provided, or they may be provided in parallel in the radial direction.

  [9. In the step of removing resist layer and protective resist layer], these may be removed using sulfuric acid / hydrogen peroxide.

  In the first embodiment, a nano-order beam diameter is used for electron beam drawing, and the alignment mark 5 is set to the sub-micron or micron order.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Hard mask layer, 2a ... Hard mask, 3 ... Resist layer, 3a ... Resist pattern, 5 ... Alignment mark, 6 ... Protection resist layer, 7 ... Data part, 8 ... Mark part, 9 ... Electron beam DESCRIPTION OF SYMBOLS 10 ... Master mold, 11 ... Protective resist layer used as weir

Claims (10)

In the substrate manufacturing method when forming alignment marks on the substrate,
Forming a resist layer so as to cover the substrate;
An exposure step of drawing or exposing a predetermined pattern by irradiating the resist layer with an energy beam;
Developing the drawn or exposed resist layer, and forming a resist pattern comprising irregularities; and a resist pattern forming step,
After the resist pattern forming step, wet etching is performed on at least a part of the substrate in the part having the resist pattern, and the size is larger than the concave part of the resist pattern in the part and is detectable using light. An alignment mark forming step of forming an alignment mark on the substrate,
A method for manufacturing a substrate, comprising: The substrate has a mark portion where the alignment mark is formed, and a non-mark portion where a concave-convex pattern is formed in other portions,
2. The beam diameter and output of the energy beam are substantially the same when forming a resist pattern at the mark portion and when forming a resist pattern at the non-mark portion. The substrate manufacturing method as described. After forming the hard mask layer so as to cover the substrate, the resist layer is formed so as to cover the hard mask layer,
The resist pattern is transferred to the hard mask layer by performing an etching process on the hard mask layer after the resist pattern forming process and before the alignment mark forming process. Substrate manufacturing method.   After the etching process for the hard mask layer and before the alignment mark forming process, the mark portion and the non-mark portion of the substrate are dry-etched, and the concave / convex pattern of the hard mask is changed to the mark portion and the non-mark portion. The substrate manufacturing method according to claim 3, wherein the substrate is transferred to a portion.   5. The substrate manufacturing method according to claim 4, wherein a protective resist layer is provided on the substrate in order to protect the concavo-convex pattern of the non-mark portion before the alignment mark forming step. A plurality of concave portions of the resist pattern are provided at equal intervals in a linear shape when viewed from the plane,
In the alignment mark forming step, at least one linear alignment mark is formed from a plurality of linear recesses in the resist pattern by overlapping a region to be cut by wet etching between adjacent recesses. The method for manufacturing a substrate according to claim 1, wherein the substrate is formed on the substrate. While the irradiation of the energy beam is an electron beam drawing having a nano-order beam diameter,
7. The substrate manufacturing method according to claim 1, wherein the alignment mark is formed in a submicron order or a micron order. The substrate is a disk-shaped quartz substrate for forming an original mold in imprinting,
The substrate has a mark portion in which the alignment mark is formed in the central portion of the substrate, while the other portion has a non-mark portion in which an uneven pattern is formed in the peripheral portion of the substrate,
The substrate manufacturing method according to claim 1, wherein the alignment mark is used for alignment when a predetermined uneven pattern of the master mold is transferred to an object to be transferred. When forming an alignment mark used for alignment when transferring a predetermined concave-convex pattern of the master mold to a transfer object on a disc-shaped quartz substrate for forming the master mold in imprinting In the substrate manufacturing method of
The substrate has a mark portion in which the alignment mark is formed in the central portion of the substrate, while the other portion has a non-mark portion in which a concavo-convex pattern is formed in the peripheral portion of the substrate,
Forming a hard mask layer so as to cover the substrate, and then forming a resist layer so as to cover the hard mask layer;
A step of performing electron beam drawing with a nano-order beam diameter on the resist layer;
The drawn resist layer is developed to form a resist pattern composed of a plurality of equidistant line-shaped irregularities when viewed from a plane in the mark portion, while in the non-mark portion, Forming a resist pattern composed of irregularities of the order;
Etching the hard mask layer and transferring the resist pattern to the hard mask layer;
Performing dry etching on the mark portion and the non-mark portion in the substrate, and transferring the concave / convex pattern of the hard mask to the mark portion and the non-mark portion;
Providing a protective resist layer so as to cover the non-marked portion in order to protect the uneven pattern transferred to the non-marked portion;
After providing the protective resist layer, wet etching is performed on the mark portion, and by overlapping the regions to be cut by wet etching between adjacent recesses, from a plurality of linear recesses in the resist pattern, Forming at least one linear alignment mark of submicron order or micron order on the mark part;
Have
When forming a resist pattern in the mark portion and forming a resist pattern in the non-mark portion, the beam diameter and output in the electron beam drawing are substantially the same, Substrate manufacturing method.   10. The substrate forming method according to claim 2, wherein the non-mark part is a data part that is a source of data of a magnetic recording medium.

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