JP2003155365A - Processing method and formed body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method having sufficient etching resistance and capable of closely transferring a formed pattern formed by self-organization and obtain a formed body in a fine processing technology using an etching mask formed by self-organization of a block copolymer. SOLUTION: This processing method comprises a process for forming a block copolymer layer, having a sequential structure in which a first polymer phase (20A) and a second polymer phase (20B) are almost regularly arranged on a material (10) to be processed, a process for forming a concave part (R) on the surface of the block copolymer by selectively removing the first polymer phase, a process for making a masking layer (30) on the concave part and a process for forming a pattern corresponding to the sequential structure of the block copolymer on the material to be processed by etching the block copolymer layer and the material to be processed by using the masking layer as a mask.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method and a molded body, and more particularly to a processing method for finely processing a pattern having a periodic array structure, which utilizes a self-organized phase-separated structure of a block copolymer. The present invention relates to a processing method and a molded product. INDUSTRIAL APPLICABILITY The processing method and the molded product of the present invention can be used, for example, in the manufacture of high-density recording media, highly integrated electronic components, and the like.

[0002]

2. Description of the Related Art The dramatic improvement in functions of information devices such as personal computers in recent years is very largely due to the progress of fine processing technology used for manufacturing semiconductor devices. Until now, the miniaturization of processing dimensions has been promoted by the shortening of the wavelength of the exposure light source used for lithography. However, as the processing size becomes finer and the pattern becomes denser, the cost of lithography in the manufacturing process becomes enormous. In a next-generation semiconductor device or a finely processed high-density recording medium such as a patterned media, it is required to miniaturize a pattern dimension to 100 nm or less. An electron beam or the like is considered to be used as an exposure light source for this purpose, but a very large problem remains in terms of processing throughput.

Against this background, a method of utilizing the phenomenon of a material self-organizing to form a specific ordered array pattern has attracted attention as a processing method that is cheaper and can realize high throughput. . Among them, in particular, the method using the “block copolymer” is capable of forming a monolayer regularly arranged pattern by simply dissolving it in a suitable solvent and coating it on the object to be processed. Application as a processing method has also been reported (for example, P. Mansky et al .; Appl. Phys. Lett., V.
ol.68, p.2586, M.I. Park et al .; Science, vol.276,
p.1401).

In these methods, one polymer phase of the phase-separated structure of the block copolymer is removed by ozone treatment, plasma etching, electron beam irradiation or the like to form an uneven pattern, and the uneven pattern is used as a mask to form a base. The substrate is processed.

However, since the size of the phase-separated structure of the block copolymer in the film thickness direction is generally equal to or smaller than the size of the pattern formed in the two-dimensional direction on the substrate, the pattern formed as a mask. It is not possible to obtain sufficient etching resistance. Therefore, when the object to be processed is etched by using the phase-separated structure of the block copolymer mask as it is as an etching mask, a structure having a sufficiently high aspect ratio cannot be processed.

In order to solve such a problem, the self-assembled pattern of the block copolymer is once transferred to a pattern transfer film provided under the block copolymer by plasma etching or the like, and the pattern transfer film is further used as an etching mask. There is also proposed a method of transferring a pattern having a high aspect ratio to the underlying resist film by etching the thick resist film of the above with oxygen plasma (Japanese Patent Laid-Open No. 2001-15).
1834, M.P. Park et al. Appl.Phys.Lett.vo
l.79 p.257).

However, even with this method, it may be difficult to faithfully transfer the pattern because a high aspect ratio cannot be obtained when transferring from the block copolymer to the pattern transfer film. Insufficient etching aspect ratio means that minute unevenness of film thickness distribution or self-assembled pattern is emphasized as variation of etching depth in the pattern transfer film and transferred to the pattern transfer film in the block copolymer film. become. In an extreme case, this may also cause a part of the pattern on the underlying resist film to disappear.

On the other hand, when utilizing self-organization, it is also important to control the arrangement direction of the regular arrangement. In the case of patterned media, which is expected to realize high density of magnetic recording media, it is necessary to access each of the patterned magnetic particles during reproduction and recording. In this case, in order to track the reproducing head to the recording row, it is necessary to arrange the magnetic particles in one direction.

Further, an electronic element such as a quantum effect device that handles a single electron as information is expected to have a possibility of further increasing the density and power consumption of a current semiconductor device. Also in this case, it is necessary to dispose electrodes for signal detection with respect to the structure that exhibits the quantum effect. Therefore, the fine structure that exhibits the quantum effect has a predetermined arrangement and, at the same time, has a region formed. Is also required to be controlled arbitrarily.

In order to control the alignment direction of the self-assembly of the block copolymer, a method has been proposed in which a groove structure is formed on a substrate and the alignment direction of particles is aligned with the groove structure as a guide (RA. Segalman et al .; Bulletti
n of the American Physical Society Vol.45 No.1 p.55
9, same vol.46 No.1 p.1000, M.K. Trawick et al .;
The same vol.46 No.1 p.1000). Although it is possible to arrange the diblock copolymers in the same alignment direction by these methods, as described above, the aspect ratio of the phase separation structure of the diblock block itself is low, so that a pattern with a sufficiently high aspect ratio is formed by etching. It is impossible to do. Also, there is currently no method for depositing diblock copolymers only in any given area.

[0011]

The present invention has been made on the basis of the recognition of the above problems, and its purpose is to:
In a fine processing technique using an etching mask formed by self-organization of a block copolymer, a processing method and a molded body having sufficient etching resistance and capable of faithfully transferring a pattern formed by self-assembly To provide.

In order to achieve the above object, a first processing method of the present invention is a block having an array structure in which a first polymer phase and a second polymer phase are arrayed in a substantially regular manner. Forming a copolymer layer on the object to be processed; forming a recess on the surface of the block copolymer layer by selectively removing the first polymer phase; and providing a mask layer in the recess. And a step of forming a pattern corresponding to the array structure of the block copolymer layer on the workpiece by etching the block copolymer layer and the workpiece with the mask layer as a mask. It is characterized by

Here, the object to be processed has an uneven pattern on the surface before the block copolymer layer is formed, and the array structure of the block copolymer layers formed on the object to be processed. Can be positively controlled if it is oriented according to the concavo-convex pattern.

Further, a second processing method of the present invention comprises a step of forming a transfer layer on the object to be processed, and a step of forming the transfer layer on the transfer layer.
A step of forming a block copolymer layer having an arrangement structure in which a first polymer phase and a second polymer phase are substantially regularly arranged, and the block copolymer layer by selectively removing the first polymer phase Corresponding to the arrangement structure of the block copolymer layer by forming a recess on the surface of the block, providing a mask layer in the recess, and etching the block copolymer layer and the transfer layer using the mask layer as a mask. And a step of etching the object to be processed by using the transfer layer as a mask.

Here again, the transfer layer has a concavo-convex pattern on the surface before the block copolymer layer is formed, and the arrangement structure of the block copolymer layers formed on the transfer layer is: The orientation of the ordered structure can be positively controlled by providing the orientation corresponding to the concavo-convex pattern.

Furthermore, in any one of the above processing methods, the size of the pattern corresponding to the array structure can be controlled by adjusting the filling amount of the mask layer in the recess.

Alternatively, in the etching performed using the mask material as a mask, the size of the pattern corresponding to the array structure can be controlled by adjusting the amount of overetching with respect to the mask material.

The processing method of the present invention is particularly useful, for example, when the pattern size to be formed is 100 nm or less, uses a self-aligned ordered structure, and
The work piece can be etched with a high aspect ratio.

Here, the etching rate of the mask layer is preferably 1/2 or less of the etching rate of the block copolymer layer.

As the transfer layer, a photocurable or thermosetting material can be used. Furthermore, when an uneven pattern for defining the orientation of the regular arrangement of the block copolymer layer is formed on the surface of the object to be processed or the transfer layer, the entire surface or the upper surface of the convex portion has a contact angle with water of 40 degrees. It is preferable to make the above hydrophobic.

A processed body is provided with a plurality of pillars continuously protruding from the support on the main surface of the support. On the other hand, in the molded article of the present invention, each of the plurality of pillars is formed. It is characterized in that it has a substantially columnar shape and has a skirt portion that becomes thicker as it gets closer to the support, in the vicinity of the joint with the support.

A molded product having such a unique shape is
Even when the pillar is formed to be extremely long and thin, the strength is maintained at the skirt portion thereof, which is advantageous in that it is possible to prevent the harmful effect of breaking from the root.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a process sectional view showing a processing method according to a first embodiment of the present invention.

First, as shown in FIG. 1A, a block copolymer film 20 is formed as a first resist layer on the object 10 to be processed. Examples of the block copolymer used here include an AB type “diblock copolymer” in which two types of polymer chains A and B are bonded. Alternatively, a “triblock copolymer” in which two types of polymer chains are bound to ABA or three types of polymer chains are bound to ABC may be used. These block copolymers are subjected to an anneal treatment at an appropriate temperature to obtain a polymer phase 20A and a polymer phase 20A.
Phase-separated with B to form an ordered array structure. For example, using the polymer phase 20B as a matrix, the polymer phase 20B
A polymer phase 20A forms a structure in which two-dimensional ordered arrangement is formed therein. The shape and size of the polymer phases 20A and 20B constituting such an ordered array structure depend on the lengths of the polymer chains A, B and C, and by adjusting these, for example, a fine size of about 100 nm or less. Can be controlled.

The regularly-arranged structure of the block copolymer thus formed may have an uneven structure in which it is regularly arranged, but it may be flat without the uneven structure. In the present invention, it is necessary to convert the phase-separated structure of the block copolymer into an uneven structure. When the surface of the ordered array structure of the block copolymer has an uneven structure as shown in FIG. 1 (b), it can be used as it is.

On the other hand, when the surface of the ordered array structure is flat as shown in FIG. 1A, at least one kind of the polymer phase 20A of the block copolymer is selectively removed, so that the structure shown in FIG. As shown in (b), a structure in which concave portions R having a hemispherical curvature similar to the shape of the polymer phase 20A are regularly arranged is formed.

In order to selectively remove the polymer phase 20A, a block copolymer is formed by two or more kinds of polymer chains having different resistances when irradiated with energy rays such as plasma, light and electron rays, and heat. Just configure it.

For example, the monomer unit N / (Nc-N
value of o) (where N is the total number of atoms in the monomer unit, Nc
Is the number of carbon atoms in the monomer unit, and No is the number of oxygen atoms in the monomer unit. The smaller the value is, the higher the resistance to various plasma irradiations. From this viewpoint, two or more kinds of polymer chains having greatly different plasma resistance may be combined.

Further, it is also possible to use a combination of a polymer chain which is cured by a cross-linking reaction or the like upon irradiation with energy rays with a polymer chain which is not cured or decomposed by irradiation with energy rays. further,
In consideration of the affinity, for example, the hydrophilicity / hydrophobicity of the polymer chain may be changed to segregate the cross-linking agent in either one of the polymer chain regions.

In this way, by selectively removing at least one polymer phase 20A of the block copolymer film having a phase-separated structure having a regular array pattern of 100 nm or less, the first recesses R are regularly arrayed. The resist layer (polymer phase) 20B can be formed.

Next, as shown in FIG. 1C, a second resist layer 30 is deposited on the first resist layer 20B. The role of the second resist layer 30 is to transfer the pattern of the recess R of the first resist layer 20B to a material having high etching resistance.

By using an inorganic material such as metal, metal oxide, metal nitride, or carbide as the material of the second resist layer 30, a mask pattern having high etching resistance against plasma etching can be formed. Alternatively, an aromatic ring-containing low molecular weight organic material may be used.
Further, a material containing a metal in the aromatic ring-containing low molecular weight organic material may be used. Furthermore, a metal-containing polymer such as Si (silicon) such as polysilane or polysiloxane may be used.

When an inorganic material or a low molecular weight organic material is used as the second resist layer 30, the first resist layer 2
A method of vacuum deposition can be used to deposit on OB. By heating the sample during vapor deposition, it is possible to selectively cause the nucleus growth in the recess R of the first resist layer 20B and selectively deposit the inorganic material in the recess R. In this way, the second resist layer 30 can be formed so as to fill the concave portion of the first resist layer 20B.

Furthermore, it is possible to bury the deposited second resist layer 30 in the recess R of the first resist layer 20B by planarizing the surface thereof by performing an annealing treatment after vacuum vapor deposition. is there.

A second polymeric material, such as a metal-containing polymer,
When it is used as the material of the resist layer 30, the first resist layer 20B may be spin-coated by being dissolved in an appropriate solvent when applied. Immediately after spin coating, the second resist layer 30 made of a polymer material is flattened by the surface tension so as to fill the recess R of the first resist layer 20B. In some cases, the surface of the first resist layer 20B may be hydrophobized before spin-coating the second resist layer 30 in order to enhance the effect of the surface tension. The surface of the first resist layer 20B can be easily made hydrophobic by exposing it to plasma of fluorine carbide.

It is also possible to spin-coat a polymer film as the second resist layer 30 and then anneal it to deposit a polymer material only in the recess R or to promote planarization.

Here, the second resist layer 30 is formed so as to completely fill the concave portion R of the first resist layer 20B and cover the flat portion thereon as shown in FIG. 1 (c). Alternatively, it may be formed so as to fill only a part of the recess R, as will be described later in detail with reference to FIG.

By using the mask pattern thus formed, as shown in FIG. 1D, the object 10 to be processed is directly etched, so that the object 10 to be processed can be finely patterned with a high aspect ratio. A pattern can be formed. That is, using the second resist layer 30 as a mask, the first resist layer 20B is etched, and further the workpiece 10 underneath is etched. Therefore, in this etching, it is necessary to select the material and etching method so that the second resist layer 30 serves as an etching mask.

If the etching selection ratio with respect to the second resist layer 30 can be ensured, the method of etching the first resist layer 20B and the object 10 to be processed thereunder.
Need not be the same as the method of etching. For example, in the case of dry etching, the first resist layer 2
It is also possible to selectively use the etching gas for etching 0B and the etching gas for etching the workpiece 10.

Further, for example, before etching the workpiece 10, RIE (Reactive Ion Etc) by oxygen plasma is performed.
By performing the hing) to etch the convex portion of the first resist layer 20B, that is, the polymer chain region (polymer phase) where the block copolymer is not removed, the workpiece 10 is etched by an appropriate method. Patterning with a high aspect ratio can be performed.

As described above, according to this embodiment, the block copolymer is phase-separated to form an ordered array, and one of the polymer phases is selectively removed to selectively etch the second resist layer having a high etching resistance. By embedding
A mask pattern is formed. With the mask pattern thus formed, the object to be processed can be etched with a high aspect ratio by appropriately selecting the etching method.

The ordered array structure of the phase-separated block copolymer can be arbitrarily controlled by adjusting the material of the polymer chain and the balance of the compounding. As a result, a fine ordered array structure of 100 nm or less can be formed in a self-organizing manner, and patterning of the object to be processed that reflects this array can be performed reliably and easily.

By the way, according to this embodiment, it is also possible to control the pattern size of the object to be processed. That is, the width of the pattern of the finally formed workpiece can be changed by adjusting the process conditions. There are two ways to do this. First, one of them is a method of adjusting the deposition amount of the second resist layer 30 shown in FIG.

FIG. 2 is a conceptual diagram for explaining a method of arbitrarily changing the area of a region serving as a mask by adjusting the deposition amount of the second resist layer 30.

For example, as shown in FIG.
Of the resist layer 30 to the recess R of the first resist layer 20B.
When it is deposited so as to completely fill the area, the masked area becomes the entire recess R. Therefore, the width W of the pattern formed by etching the workpiece 10 is about the same as the outer edge size of the recess R as shown in the figure.

On the other hand, as shown in FIG. 2B, since the concave portion R has a hemispherical curvature, the second resist layer 30 is reduced to the second portion when the deposition amount of the second resist layer 30 is reduced. Since the portion covered with the resist layer 30 becomes smaller and the area of the portion acting as a mask becomes smaller, the pattern width W of the finally obtained workpiece 10 can also be made smaller. This utilizes the fact that the concave portion R is formed in a curved shape.

As described above, according to this embodiment, the mask size can be changed by adjusting the deposition amount of the second resist layer 30, and accordingly, the pattern size of the workpiece can be changed. Can be controlled.

In this case, the second resist layer 3
By using an etching method having a sufficiently low etching rate for 0, accurate patterning corresponding to the second resist layer 30 can be performed.

Now, another method of adjusting the pattern size of the object to be processed is a method of over-etching the second resist layer 30 acting as a mask.

FIG. 3 is a conceptual diagram for explaining that the pattern size of the object to be processed changes by overetching the second resist layer.

As shown in FIG. 5A, the second resist layer 30 was deposited so as to fill the recess R of the first resist layer 20B, and was etched with a high selectivity using this as a mask. In this case, the pattern width W1 of the workpiece 10 is
It is the same as the outer edge of the second resist layer 30, that is, the outer edge of the recess R. In order to perform accurate patterning according to the outer edge of the mask in this manner, it is desirable to use a method having high anisotropy and suppressing side etching as the etching method.

On the other hand, when the over-etching is performed under the condition that the second resist layer 30 is also etched to some extent, the second resist layer 30 serving as a mask is formed as shown in FIG. 3B. , The layers gradually disappear from the outer edge. Then, the first resist layer 2 thereunder
OB and the workpiece 10 are etched. As a result, the pattern widths W2 to W4 of the workpiece 10 can be appropriately reduced according to the amount of overetching. That is, according to this embodiment, the pattern width of the workpiece 10 can be controlled by appropriately overetching the second resist layer 30.

Here, the pillar-shaped pattern having a substantially columnar shape formed by over-etching has a skirt G at the lower end of which the pattern width gradually changes. This skirt portion G is formed by the progressive etching from the outside accompanying the over-etching of the second resist layer 30. In this way, by forming the skirt portion G that becomes gradually thicker at the lower end of the pillar of the workpiece 10, it is possible to prevent the pillar from being broken from the root. This effect is
This is particularly remarkable when etching with a high aspect ratio is performed. Further, in the size adjusting method using this over-etching, it is preferable that the method of etching the first resist layer 20B and the etching method of processing the workpiece 10 are different. That is, it is possible to independently control the size in the step of etching the first resist layer 20B.

Next, in the present invention, a structure advantageous for regularly arranging the phase separation structure of the block copolymer will be described.

FIG. 4 is a schematic diagram showing a method of regularly arranging the phase separation structure of the block copolymer.

That is, as shown in FIG. 3A, a two-dimensional uneven pattern is formed on the object to be processed 10.
As a method of forming this, a method such as lithography can be used. Photolithography or the like can be used as a means of lithography, but it is not limited to this.

When the block copolymer is deposited on such an object 10 to be processed, as shown in FIG. 4 (b), the phase-separated structure is oriented in the recess C and is regularly arranged in a predetermined direction. A periodic structure is obtained.

Here, it is preferable that the concave-convex pattern includes concave portions C wider than the lattice spacing of the regular arrangement structure of the block copolymer, that is, the period. This is because the block copolymer is confined in the recesses C, and it promotes that the ordered arrangement occurs only in the recesses C. In the recess C,
In order to form the periodic array by orienting the phase-separated structure, it is desirable that the width of the recess C be approximately several times to several hundreds times the lattice spacing of the periodic array.

On the other hand, it is desirable that the depth of the recesses C be smaller than the lattice spacing of the ordered array structure of the block copolymer. This is because when the recesses deeper than the lattice spacing of the ordered array structure are formed, a phase-separated structure regularly stacked in the film thickness direction may be formed. However, when using a block copolymer in which the cylinder structure or the lamella structure is oriented perpendicular to the film surface, it is also possible to use a concavo-convex pattern in which the depth of the recesses C is larger than the lattice spacing of the regular array structure. is there.

FIG. 5 is a schematic view showing a method for making the surface of the object to be processed 10 hydrophobic.

That is, as shown in FIG. 3A, only the upper surface of the convex portion of the concavo-convex pattern is made hydrophobic, and the hydrophobic layer 1 is formed.
To form 0H. Then, since the block copolymer 20 is repelled in the hydrophobized layer 10H, it is possible to deposit the block copolymer only in the recess C as shown in FIG. The block copolymer thus deposited forms a phase-separated structure oriented according to the size of the recess C.

In order to form the concavo-convex pattern shown in FIG. 5A, the surface of the object to be processed 10 is first uniformly covered with a thin film such as SiO _{2 which} can be made hydrophobic. A resist is applied from above and a predetermined portion is subjected to a hydrophobic treatment. For the hydrophobic treatment, a silane coupler such as octadecyltrimethylsilane or hexamethyldisalazan or a surfactant such as alkanethiol can be used.

In addition to the example shown in FIG. 5, the entire surface of the concavo-convex pattern may be uniformly made hydrophobic. When hydrophobized, the contact angle becomes large, so that it does not become a thin film on a flat surface and repels droplets, but since there is a vertical surface in the recess, it does not form a droplet even if the contact angle is large. Can exist. However, in this case, it is necessary to adjust the degree of hydrophobization, and it is more reliable to hydrophobize only the protrusions.

On the other hand, the concavo-convex pattern may be a periodic pattern having concave portions having a size smaller than the lattice spacing of the regular arrangement structure of the block copolymer. In this case, it is possible to orient one of the polymer layers constituting the phase-separated structure on the recess corresponding to the recess. As a result, the phase separation structure of the block copolymer can be regularly arranged in a predetermined direction.

(Second Embodiment) Next, the second embodiment of the present invention will be described.
As an embodiment, a processing method for forming a fine pattern on a workpiece through a transfer layer will be described.

FIG. 6 is a process sectional view showing the processing method of this embodiment.

First, as shown in FIG. 1A, a transfer layer 4 made of a carbon-based organic polymer material or the like is formed on the object 10 to be processed.
Apply 0. Here, the carbon-based polymer material is used.
This transfer layer 4 is formed by oxygen plasma etching in a later step.
This is because the pattern is transferred to 0. Specific examples of the carbon-based organic polymer material include materials having high etching resistance such as polystyrene, polystyrene derivatives such as polyhydroxystyrene, polyvinyl naphthalene and its derivatives, novolac resin, and polyimide.

Subsequently, the block copolymer layer 20 is applied onto the formed transfer layer 40 by a spin coating method or the like, and annealed at an appropriate temperature to cause phase separation and regular arrangement.

Next, as shown in FIG. 6B, the polymer phase 20A forming a part of the phase-separated block copolymer layer 20 is selectively removed. That is, as described above with reference to FIG. 1, the polymer phase 20A is removed by means such as energy beam irradiation to form the first resist layer 20B in which the recesses R are regularly arranged.

Next, as shown in FIG. 6C, the second resist layer 30 is formed on the first resist layer 20B. In this modified example, the pattern of the second resist layer 30 (that is, the portion of the recess R) is used as a mask to transfer the pattern to the transfer layer 40 by oxygen plasma or the like. It is desirable to use a material having high resistance to oxygen plasma.

For example, metal, metal oxide, metal nitride,
By using an inorganic material such as carbide, a mask pattern having high oxygen plasma etching resistance against plasma etching can be formed. Alternatively, an aromatic ring-containing low molecular weight organic material may be used. A material containing a metal in the aromatic ring-containing low molecular weight organic material may be used. A polymer containing a metal such as Si (silicon) such as polysilane or polysiloxane may be used.

Since the etching resistance of these materials to oxygen plasma is much higher than that of the carbon-based organic polymer material, the pattern transfer to the transfer layer 40 is realized with an extremely high aspect ratio in this example. be able to.

Here, the deposition of the second resist layer 30 is performed as follows.
It can be performed in the same way as the method described above with reference to FIG.

Next, as shown in FIG. 6D, RIE by oxygen plasma is performed on the second resist layer 30 so that the second layer of the second resist layer 30 is formed on the transfer layer 40.
Transfer the dimensional rule pattern.

Then, as shown in FIG. 6E,
The workpiece 10 is etched by using the transfer layer 40 as a mask to form a predetermined fine pattern. Here, the second resist layer 30 and the first resist layer 20B may be removed prior to the etching of the object 10 to be processed, or the etching of the object 10 to be processed may be started while the second resist layer 30 and the first resist layer 20B are left. .

As described above, according to the processing method shown in FIG. 6, the predetermined fine pattern is transferred to the transfer layer 40, and then the workpiece 10 is etched by using this as a mask. By thus interposing the transfer layer 40, it is possible to further increase the etching selection ratio. That is, by using a suitable material for the second resist layer 30 and the transfer layer 40 and selecting an optimum etching method in each of the etching steps shown in FIGS. The etching selection ratio with respect to the body 10 can be further increased, and a fine pattern with a high aspect ratio can be formed.

Also in this embodiment, as described above with reference to FIGS. 2 and 3, the coating amount of the second resist layer 30 is adjusted, or the second resist layer 30 is appropriately overetched. The size of the pattern transferred to the transfer layer 40 can be adjusted, and as a result, the size of the fine pattern formed on the workpiece 10 can be controlled.

Furthermore, also in the embodiment of the present invention,
It is possible to previously form a concavo-convex pattern for controlling the orientation of the ordered arrangement structure of the block copolymer as illustrated in FIG. 4 on the transfer layer 40.

FIG. 7 is a process sectional view showing a specific example in which a concavo-convex pattern is formed on the transfer layer 40.

First, as shown in FIG. 7A, recesses C for controlling the orientation of the ordered array structure are formed in the transfer layer 40 formed on the workpiece 10.

The recess C may be formed by lithography by coating another resist on the transfer layer 40. When a carbon-based organic polymer material or the like is used as the material of the transfer layer 40, its surface is very soft. Therefore, the concave-convex pattern of a predetermined master may be directly transferred by the “nanoimprint method”.

The transfer layer 40 is cured before or after forming the recess C. This is important in order to prevent the pattern formed on the transfer layer 40 from being destroyed by the solvent of the first resist layer applied to the transfer layer 40, that is, the block copolymer, or the annealing treatment for the regular arrangement.

As shown in FIG. 7B, the transfer layer 40 is cured by light irradiation or heating. As the photocurable resin, polystyrene, polybutadiene, polyisoprene, novolac resin, diazo resin or the like can be used. As the thermosetting resin, polyacrylonitrile derivative, polyamic acid, polyimide, polyaniline derivative, polyparaphenylene derivative, polycyclohexadiene derivative, polybutadiene, polyisoprene,
Novolac resin or the like can be used.

In order to cure the polymer chain more efficiently, it is also effective to add a radical generator such as an organic peroxide or a crosslinking agent to accelerate the crosslinking reaction and cure.

These hardening treatments may be carried out before the pattern formation or after the pattern formation. When the curing treatment is performed after the pattern formation, the pattern collapse may occur during the thermal curing, and thus the photocuring is preferable. The combined use of photo-curing and heat-curing further accelerates the curing reaction and enhances heat resistance and solvent resistance. When the pattern of the master is directly transferred by nanoimprint, the transfer layer 4 is heated by heating or irradiating the substrate while the master is being pressed.
0 may be hardened.

In this way, after forming the predetermined recess C in the transfer layer 40 and curing it, the block copolymer 20 is applied. After that, the fine pattern can be formed on the workpiece 10 by the series of processes described above with reference to FIG. In addition, here, also when the uneven pattern is formed on the surface of the transfer layer 40, the surface of the transfer layer 40 can be subjected to the hydrophobic treatment as described above with reference to FIG. By doing so, the block copolymer can be separately deposited only in the recess C of the transfer layer 40. In this case, since the surface of the transfer layer 40 has no reactive group for the silane coupler or alkanethiol, they cannot be used for the hydrophobic treatment. The hydrophobizing treatment can be performed by exposing the sample to a fluorocarbon plasma to deposit a fluorocarbon polymer on the surface.

[0086]

Embodiments of the present invention will be described in more detail below with reference to embodiments.

(First Example) According to the processing method of the first embodiment of the present invention, a block copolymer of polystyrene / polymethylmethacrylate is used as the block copolymer 20 for forming the first resist layer. Fine processing was performed using spin-on-glass (SOG) as the resist layer 30 of FIG.

The process will be described below with reference to FIG.

First, as shown in FIG. 1A, as a block copolymer 20, polystyrene (PS) with a molecular weight of 170,000 and poly with a molecular weight of 40,000 are prepared on a silicon (Si) substrate prepared as a workpiece 10. Diblock copolymer consisting of methyl methacrylate (PMMA) is propylene glycol monomethyl ether acetate (PGME
What was dissolved in A) was applied by spin coating so as to have a film thickness of 60 nm. Then, by annealing at 210 ° C. for 30 hours in a hydrogen reducing atmosphere, the phases were separated to form a regular array structure.

Next, as shown in FIG. 1B, the recess R
Was formed. Specifically, the flow rate of oxygen is 300 sccm,
The polymer phase 20A of PMMA was removed by reactive ion etching (RIE) for 20 seconds under conditions of a total pressure of 200 mTorr and an input RF power of 300 W.

At this point, when observing the surface of the block copolymer layer with an atomic force microscope (AFM), it was confirmed that the recesses R having a diameter of about 45 nm, a depth of about 20 nm and an interval of about 80 nm were arranged in a hexagonal lattice. Was done.

Next, as shown in FIG. 1C, SOG was formed as the second resist layer 30. In particular,
SOG was dissolved in ethyl lactate and applied by spin coating.

Then, as shown in FIG. 1D, etching was performed from above. Specifically, the oxygen flow rate 2
0 sccm, total pressure 30 mTorr, input RF power 10
RIE was performed under the condition of 0 W for 100 seconds.

FIG. 8 is an AFM image of the sample surface thus obtained. As can be seen from the figure, it was confirmed that the ordered array structure of the diblock copolymer was accurately transferred to the SOG structure.

Comparative Example For comparison with the above-described first embodiment, a transfer layer is placed under the block copolymer, and a thick resist film is placed under the transfer layer. An example of transferring a pattern will be described.

First, a novolac resin was applied as a thick resist film to a thickness of 100 nm on a silicon (Si) substrate, and then SiO ₂ was deposited as a transfer layer to a thickness of 15 nm by a vacuum evaporation method. . Furthermore, the same diblock copolymer as that used in the first example was applied thereon so that the film thickness would be 60 nm.

Next, the block copolymer was phase-separated by anneal at 210 ° C. for 30 hours to form an ordered array, and the PMMA polymer chain region (polymer phase 20A) was removed by oxygen RIE as in the first embodiment. And then CF
₄ flow rate 20 sccm, total pressure 30 mTorr, input RF
RIE was performed for 15 seconds under the condition of a power of 100 W to transfer the pattern to the SiO ₂ transfer layer.

Then, similarly to the first embodiment, the pattern was transferred to the novolac resin as the underlying thick resist film by oxygen RIE. Here, it is desirable that the transfer pattern thus obtained has the same concavo-convex shape as the pattern on the surface of the block copolymer.

FIG. 9 is an AFM image of the sample surface thus obtained. As can be seen from the figure, the diameters of the recesses formed on the surface of the novolac resin layer have many “variations”, and the recesses formed by removing the polymer phase 20A are not properly transferred to the novolac resin layer. Do you get it.

(Second Example) Next, using the processing method of the second embodiment of the present invention, the magnetic film is etched to form "patterned media" in which fine magnetic dots are periodically arranged. A specific example in which the above is formed will be described with reference to FIG. 6 as appropriate.

First, cobalt platinum (Co
The Pt) alloy 10 was deposited by a sputtering method so as to have a film thickness of 60 nm.

Next, 120 n of novolac resin is applied on top of it.
m to a film thickness of 30 minutes at 210 ° C.
Then, the novolac resin layer 40 was cured. Then, from above, the diblock copolymer 20 similar to that of the first embodiment is obtained.
Was applied so as to have a film thickness of 60 nm, and an annealing treatment was performed at 210 ° C. for 30 hours to cause phase separation and regular arrangement.

Next, oxygen RIE is performed under the same conditions as in the first embodiment.
To remove the PMMA polymer chain region (polymer phase 20A).

Then, SOG 30 was spin-coated on the same as in the first embodiment, and then the pattern was transferred to the novolac resin layer 40 by oxygen RIE as in the first embodiment.

Next, using this novolac resin layer 40 as a mask, CoP is performed by argon (Ar) ion milling.
The t film was etched.

FIG. 10 shows the CoP thus obtained.
It is a scanning electron microscope (SEM) image of t dots. It was confirmed that CoPt dots having an extremely high aspect ratio with a width-height ratio of about 1: 3 were formed on the glass substrate.

(Third Example) Next, using the processing method of the second embodiment of the present invention, a method of aligning the orientation of a regular array by forming an uneven pattern on the transfer layer 40 is used. A specific example of producing a patterned medium of a magnetic material will be described with reference to FIGS. 6 and 7 as appropriate.

First, a cobalt platinum chromium (CoPtCr) thin film 10 was formed to a thickness of 40 nm on a glass disk substrate by sputtering. On top of that, add novolac resin 40
It was applied to a film thickness of 20 nm. Then, on the surface of the novolac resin 40, the width of the convex portion is 320 nm and the width of the concave portion is 7 nm.
A master disk on which a concentric concavo-convex pattern having a depth of 0 nm and a recess depth of 60 nm was formed was nanoimprinted under a pressure of 30 tons. As a result of this, the novolac resin 40
On the surface of, an uneven pattern was formed by reversing the pattern of this master.

Next, after irradiating with deep ultraviolet light of 300 W for 3 minutes, the pattern of the novolak resin 40 formed by imprinting was cured by annealing at 210 ° C. for 30 minutes.

From above, as in the first embodiment,
The diblock copolymer 20 was applied, annealed and regularly arranged, and then the PMMA polymer chain region (polymer phase 20A) was removed by oxygen RIE.

Next, SOG 30 is spin-coated from above, and the resist layer 20B and the novolac resin 40 are etched by oxygen RIE using this as a mask.
The pattern was transferred to the novolac resin 40. Then, similarly to the second embodiment, the magnetic film 10 was etched by Ar ion milling using the novolac resin 40 as a mask.

FIG. 11 shows the CoP thus obtained.
It is a SEM image showing the magnetic dot of tCr. It was confirmed that on the glass substrate, the magnetic dots 10D were formed in four concentric circles with fine alignment.

(Fourth Example) A specific example in which a single-electron device is manufactured by using the processing method according to the second embodiment of the present invention will be described with reference to FIGS. 6 and 7.

First, a silicon oxide film having a layer thickness of 200 nm was formed on a silicon substrate, and then a titanium (Ti) and gold (Au) thin film 10 was sequentially formed to have a thickness of 5 nm and 20 nm.

A novolac resin layer 40 is formed on the surface of the novolak resin layer 100 by 100.
After application to a film thickness of nm, a recess having a width of 50 nm, a length of 500 nm and a depth of 20 nm was formed by nanoimprinting.

Then, 300 W deep UV light was irradiated for 3 minutes and annealed at 210 ° C. for 30 minutes to obtain PS molecular weight of 600.
00, a diblock copolymer film 20 having a PMMA molecular weight of 12000 was applied so as to have a film thickness of 20 nm, and annealed at 210 ° C. for 30 hours for phase separation.

Next, the PMMA portion (polymer phase 20A) was removed by oxygen plasma treatment, SOG 30 was applied, and the novolac resin 40 was etched by oxygen RIE to form a fine pattern mask.

Then, using this novolac resin 40 as a mask, a thin layer of titanium / gold 10 was formed by Ar ion milling.
To form a titanium / gold dot array.

After that, a resist is applied, a resist pattern is formed by photolithography so as to mask a part of the titanium / gold dot row, and titanium (T
i), a gold (Au) thin film is sequentially formed to have a film thickness of 5 nm and 20 nm, and then the resist is lifted off to form a source electrode,
A drain electrode was formed.

FIG. 12 is a conceptual diagram showing the planar structure of the single electron device thus obtained. Source electrode S
When the voltage-current characteristics were measured between the drain electrode D and the drain electrode D, it was confirmed that the current changed stepwise and single electrons were confined near the surface of the silicon substrate corresponding to the titanium / gold dots.

The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the block copolymer, the second resist layer, the transfer layer, or the material, shape, size, etc. of the object to be processed used in the present invention are appropriately selected by those skilled in the art, and the present invention can be carried out in the same manner, with the same effect. What can obtain is also included in the scope of the present invention.

Further, the processing method of the present invention is not limited to the above-mentioned patterned media and single-electron device, and it is also within the scope of the present invention to carry out the same in various other applications and obtain the same effect. Included in.

In addition, all processing methods which can be appropriately modified and carried out by those skilled in the art based on the processing methods described above as the embodiments of the present invention also belong to the scope of the present invention.

[0124]

As described above, according to the present invention,
By forming a mask pattern with very few defects and excellent etching resistance at low cost and with high throughput, various products such as high density recording media and highly integrated electronic parts can be manufactured. It is possible to provide a processing method that is manufactured by a practical process and cost, and industrial merits are great.

[Brief description of drawings]

FIG. 1 is a process sectional view illustrating a processing method according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining a method of arbitrarily changing the area of a region serving as a mask by adjusting the deposition amount of a second resist layer 30.

FIG. 3 is a conceptual diagram for explaining that the pattern size of a workpiece is changed by overetching the second resist layer.

FIG. 4 is a schematic diagram showing a method for regularly arranging the phase separation structure of a block copolymer.

FIG. 5 is a schematic view showing a method for making the surface of the object to be processed 10 hydrophobic.

FIG. 6 is a process sectional view illustrating a processing method according to a second embodiment of the present invention.

FIG. 7 is a process cross-sectional view showing a specific example in which a concavo-convex pattern is formed on a transfer layer 40.

FIG. 8 is an AFM image of the sample surface obtained in the first example of the present invention.

FIG. 9 is an AFM image of a sample surface obtained in a comparative example.

FIG. 10: CoP obtained in the second embodiment of the present invention
It is a scanning electron microscope (SEM) image of t dots.

FIG. 11: CoP obtained in the third embodiment of the present invention
It is a SEM image showing the magnetic dot of tCr.

FIG. 12 is a conceptual diagram showing a planar configuration of a single-electron device obtained in a fourth example of the present invention.

[Explanation of symbols]

10 Workpiece 10H hydrophobic layer 20 block copolymer layer 20A, 20B polymer phase 20B First resist layer 30 Second resist layer 40 Transfer layer C recess D drain electrode G foot part R recess S source electrode

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 12, 2001 (2001.12.
12)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 7

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

On the other hand, the molded product of the present invention is a molded product in which a plurality of pillars continuously protruding from the support are provided on the main surface of the support, while the molded product of the present invention is Is that each of the plurality of pillars has a substantially columnar shape with a diameter of 100 nm or less, and has a skirt portion that becomes thicker toward the support body in the vicinity of the joint with the support body. Characterize.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/3065 C08L 53:00 // G03F 7/26 511 H01L 21/30 502R C08L 53:00 21/302 H (72) Inventor Toshiro Hiraoka 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Stock company inside the Toshiba Research and Development Center (72) Inventor Katsuyuki Naito 1 Komu-shishi-cho, Saiwai-ku, Kawasaki, Kanagawa Stock company Toshiba Research and Development Center F-term (reference) 2H096 AA25 BA09 HA30 KA19 4F006 AA58 AB73 CA02 DA01 EA03 4F073 AA06 BA34 BB09 CA49 CA51 5D112 AA05 AA16 FA04 GA18 GA20 5F004 BA04 DA26 DB01 DB08 EA04 EA08 EB08

Claims (7)

[Claims] 1. A step of forming a block copolymer layer having an array structure in which a first polymer phase and a second polymer phase are substantially regularly arranged on a workpiece, and the first polymer phase Forming a recess on the surface of the block copolymer layer by selective removal, providing a mask layer in the recess, and etching the block copolymer layer and the workpiece with the mask layer as a mask And a step of forming a pattern corresponding to the arrangement structure of the block copolymer layer on the object to be processed. 2. The object to be processed has an uneven pattern on the surface before the block copolymer layer is formed, and the array structure of the block copolymer layers formed on the object to be processed is 2. The processing method according to claim 1, wherein the patterning is performed corresponding to the concavo-convex pattern. 3. A step of forming a transfer layer on a workpiece, and a block having an array structure in which a first polymer phase and a second polymer phase are arranged in a substantially regular manner on the transfer layer. Forming a copolymer layer; forming a recess on the surface of the block copolymer layer by selectively removing the first polymer phase; providing a mask layer in the recess; Etching the block copolymer layer and the transfer layer as a mask to form a pattern on the transfer layer corresponding to the array structure of the block copolymer layer; and etching the object to be processed using the transfer layer as a mask. And a step of: 4. The transfer layer has a concavo-convex pattern on its surface before the block copolymer layer is formed, and the arrangement structure of the block copolymer layers formed on the transfer layer is the The processing method according to claim 3, wherein the orientation is made in correspondence with the uneven pattern. 5. The size of the pattern corresponding to the array structure is controlled by adjusting the filling amount of the mask layer in the concave portion, according to any one of claims 1 to 4. Processing method. 6. The size of a pattern corresponding to the array structure is controlled by adjusting an overetching amount with respect to the mask material in the etching performed using the mask material as a mask. The processing method according to any one of 4 to 4. 7. A processed body in which a plurality of pillars continuously protruding from the support body are provided on a main surface of the support body, each of the plurality of pillars having a substantially cylindrical shape, and ,
A molded article, characterized in that it has a skirt portion that becomes thicker as it approaches the support, in the vicinity of the joint with the support.