JP2005354017A - Optically-hardening reaction control imprint mold and imprint processing method using the same, and imprint processed product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small imprint device that does not generate an optically hardened resinous film after irradiating light. <P>SOLUTION: In an optically-hardening reaction control imprint mold 1, an optically-hardening imprint mold 1 uses a substrate of optically-transparent artificial quartz, sapphire, polycarbonate, etc., and has a convexo-concave pattern formed thereon. A resinous film, an inorganic film, and the like for controlling an optically-hardening reaction are formed onto the convexo-concave pattern. Also, an imprint processing method is disclosed using the same. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

Detailed Description of the Invention

  The present invention relates to an imprint mold for pressing a mold having a fine uneven pattern shape of nano and micron level to a printed member, and transferring and printing the uneven pattern shape on the printed member, and imprint processing using the same The present invention relates to an imprinted product using a method, an imprint mold, and a processing method.

Optical disks such as CD-ROMs and DVD-ROMs are currently made by a dot pattern resin molding method using a metal resin molding die created by photolithography. Data such as video and music are recorded as dot patterns on this optical disc, and this is read and reproduced with laser light.
Also, in magneto-optical disks such as MO, a magnetic thin film is formed as a recording thin film after forming a dot pattern with a metal mold. The MO is commercially available as a recording medium that can read the data of the recording thin film with a laser beam, as well as erasing and writing, and capable of repeated recording (erasing and writing). Recently, these recording media have been required to improve recording density year by year due to high market demands such as reduction in size and weight, portability, storability, manageability, and increase in capacity. In a method called a photoimprint method, a photo-curable photosensitive resin is used as a pattern forming resin. The pattern forming mold is mainly made of a substrate such as artificial quartz or sapphire that can transmit light. A fine pattern is formed on this substrate by the EB method (electron beam method), and the unevenness is formed by dry etching. The formed mold is used. In the imprint, even if the mold material is not metal, it is customarily called a mold. In the EB method, it is easy to form a dot pattern of 100 nanometers or less. By using this as a mold, it is possible to form a high-density recording medium. In addition, by using a photo-curing type resin for recording media, it becomes possible to form dot patterns at a lower temperature than when thermoplastic resins are used. There is a feature that enables high-density recording.

In the case of a conventional CD-ROM, MO, etc., the normal dot pattern has a width of 0.4 μm, a depth of 0.4 μm, and a length of 0.9 to 3.3 μm. On the other hand, in the optical imprint method, it is possible to form a dot pattern of 1/10 size, and a recording density of 10 times can be achieved. The development of this optical imprint technology is expected to enable the production of a 100 GB recording medium in the near future.
This optical imprint technology was first introduced by Chou in 1995. Although there are still few academic papers in this field, it is introduced as the current state of nanoimprint technology, for example, in the Journal of Abrasive Grains, Vol. 46, No. 6, p282, (2002). Among these, sapphire, which has a pattern formed with EB and has irregularities formed by dry etching, is used for the mold, and the resin is cured by irradiating ultraviolet rays from above. This sapphire mold is called a mold in the paper. Also, a drawing of a printing apparatus is published as an optical imprint lithography apparatus. The mold holding part of this introduction paper is shown in a sectional view in FIG. According to this, the sapphire imprint mold 1 is on the upper side, and the substrate (printed member) 2 is disposed on the stage 4 below, and the stage 4 is raised in the direction of the stage rising arrow 6. The sapphire mold 1 is pressed.

The fine printing technique using this conventional imprint mold will be described in more detail with reference to FIG. In the prior art, first, as shown in FIG. 2 (a), an imprint mold 1 is prepared by using a light-transmitting substrate (printed member) 2 such as artificial quartz or sapphire and processing the shape of the irregularities on the surface. . The shape processing of the concavo-convex pattern of the imprint mold 1 is performed, for example, by dry etching after resist coating to EB processing or chemical wet etching as described above. Next, the imprint mold 1 is aligned with the substrate (printed member) 2 coated with the photocurable photosensitive resin 7 and pressed while applying mechanical pressure in the air, under reduced pressure, or in vacuum. . Since the photo-curable photosensitive resin 7 has pressure fluidity at an uncured stage, a replica resist pattern is formed on the substrate (printed member) 2 along the uneven shape of the imprint mold 1 by pressurization. It is formed. The method performed under reduced pressure or in vacuum is suitable for finer imprint processing because the photosensitive resin, the mold, and the internal gas body between the mold and the substrate can be discharged.
Next, when the imprint mold 1 is peeled from the substrate (printed member) 2 after being irradiated with ultraviolet rays, a photo-curing resin pattern 8 in which the photo-curing reaction has ended is formed. At this time, a photocurable resin residual film 9 that could not be completely removed by the imprint mold 1 is also formed. Since this photocuring resin residual film 9 is similarly irradiated with ultraviolet rays, the photocuring reaction is completed. Next, for example, dry chemical etching or plasma ashing is performed in order to remove the photocured resin residual film 9, whereby a final replica resist pattern (d) is completed. Further, when the substrate (printing member) 2 is finely etched using the replica resist pattern, an etching pattern 10 which is the reverse pattern of the imprint mold 1 is formed on the substrate (printing member) 2. The Fine etching of the substrate (member to be printed) 2 is usually performed by a method such as dry etching or wet chemical etching.

Problems to be solved by the invention

As described in the prior art, the photosensitive resin flows under pressure by pressing the mold to form an uneven replica resist pattern, but at the same time, a photocuring resin residual film is also formed. For this reason, as a means for reducing the thickness of the photocurable resin residual film, measures such as increasing the pressure during printing are usually taken. However, when the pressure is increased, a large force is applied to the imprint mold, which not only causes damage to the imprint mold, but also increases the size of the imprint mold mounting structure of the imprint apparatus, which increases the overall size of the apparatus. There are disadvantages such as. In particular, in optical imprinting, the upper part of the imprint mold needs to be released for light irradiation, and therefore the imprint mold is held using a jig that supports the periphery of the mold. If a large force is applied to the jig, the imprint mold will bend and deform, and there is a limit to increasing the pressure.
Furthermore, in dry etching for removing the photocuring resin residual film, if the photocuring resin residual film is to be completely removed, there is a risk of etching and damaging the replica resist pattern other than the photocuring resin residual film. This is particularly a problem with fine dot patterns of 50 to 100 nm.

Therefore, the problem to be solved by the invention is
1) Eliminate the photocuring resin residual film after light irradiation.
2) To reduce the size of the imprint apparatus.
3) To enable finer pattern formation.
4) To shorten the imprint process and reduce the cost of processed products applying the final imprint technology by reducing the process.
It is.

Means for solving the problem

  A photo-curing reaction control film capable of blocking photo-curing reaction is provided in a photo-curing imprint mold using a light-transmitting artificial quartz, sapphire, polycarbonate, or the like and forming a concave-convex pattern on the substrate.

  One means for solving the problem will be described with reference to FIG. As shown in FIG. 3A, a photocuring reaction control polymer film 11 is provided on the surface of the convex portion of the imprint mold 1. The photocuring reaction control polymer film 11 is made of a functional polymer film such as a blocking film for light having a wavelength of a light source used for the photocuring reaction or an absorption film. For example, if the resist film used in the dry etching process of the mold is a material that does not transmit ultraviolet rays, the photocuring reaction control polymer film is not peeled off and the photocuring reaction control polymer film is used as it is. It is also possible to use as When the imprint mold having the photocuring reaction control polymer film is aligned with the substrate (printed member) 2 coated with the photocurable photosensitive resin 7 and pressed while pressing (FIG. 3B). )), The photo-curing photosensitive resin 7 directly under the photo-curing reaction control polymer film does not proceed with the photo-curing reaction. Accordingly, the remaining film remaining uncured is soluble in water or a solvent, so that the photo-curing resin pattern 8 appears by simple cleaning immediately after the mold is peeled (FIG. 3C). The etching pattern 10 is completed when the substrate is etched by various dry etching or wet chemical etching methods using the photocurable resin pattern 8 as a resist (FIG. 3D).

Another means will be described with reference to FIG. In FIG. 4, a polymer mold 1 b is used as the imprint mold 1. A photocuring reaction control polymer film 11 is formed on the polymer mold 1b. The photocuring reaction control polymer film 11 can be formed by exposing and developing a photosensitive resin using, for example, a photomask. In the case of a non-photosensitive resin, the pattern may be formed by an excimer laser, a carbon dioxide gas laser, or the like. The thickness of the photocuring reaction control polymer film can be selected depending on the thickness of the photosensitive resin or non-photosensitive resin that is first applied onto the mold base substrate 1a. As the photosensitive resin or non-photosensitive resin in this case, a resin having a characteristic capable of blocking light from a light source used for exposure of the photocurable photosensitive resin is selected. For the mold base substrate 1a, a plate made of, for example, artificial quartz, sapphire, or polycarbonate that transmits ultraviolet rays is used.
When this polymer mold 1b is aligned with a substrate (printing member) 2 coated with a photo-curable photosensitive resin, as in FIG. 3, and pressed with pressure (FIG. 4 (b)), a photo-curing reaction is performed. The photo-curing reaction does not proceed with the photosensitive resin directly under the control polymer film. Therefore, the remaining film remaining uncured is soluble in water or a solvent, so that the photo-curing resin pattern 8 appears by simple cleaning immediately after the mold is peeled off (FIG. 4C). Etching pattern 10 is completed when the substrate is etched by various dry etching or wet chemical etching methods using this photo-curing resin pattern as a resist (FIG. 4D).

Another means will be described with reference to FIG. In this example, the method is based on an inorganic film mold 1c using a photocuring reaction control inorganic film 12 as a photocuring reaction control film. The photocuring reaction controlled inorganic film 12 may be, for example, a chromium vapor deposition film used for a metal mask for photolithography, an electroless plating film such as nickel, or a ceramic film such as chromium oxide. This photocuring reaction controlled inorganic film 12 can be formed by photolithography after vapor deposition or plating. In the case of forming by electroplating such as copper, first, a vapor deposition thin film such as copper is formed on the entire surface of the mold base substrate 1a. Thereafter, an electroplating resist pattern is formed on the vapor-deposited thin film, and electroplating with a required thickness is performed. Finally, the photocuring reaction controlled inorganic film can be formed by a method of peeling the electroplating resist and the copper deposited thin film immediately below the electroplating resist. This photocuring reaction controlled inorganic film has a characteristic that the film characteristics are not deteriorated by irradiation with ultraviolet rays or the like.
By using an imprint mold having this photocuring reaction controlled inorganic film, a photosensitive resin pattern without a photocuring resin residual film can be formed. As described above, various dry etching and wet chemical etching of a substrate (printed member) Can do

  Further, there is a method of using a polymer sub mold using a master mold manufactured by an EB processing method or the like for forming a fine pattern. This method is the same method as shown in FIG. 2, and artificial quartz or sapphire that transmits ultraviolet rays is used for the substrate (member to be printed) 2. A photosensitive resin film capable of blocking ultraviolet rays is formed thereon, and when the ultraviolet rays are irradiated using the imprint mold 1 as a master mold, a sub-master plate (replica plate) for the master mold is completed (FIG. 1 (d) )). In this method, a photocurable resin residual film is formed as shown in FIG. 1, and thus the photocurable resin residual film 9 in the recesses is removed by dry etching or the like while taking care not to damage the photocurable resin pattern 8. This method has a feature that a very fine pattern of 50 nm to 1 μm can be formed because a master mold is formed by EB processing. By using an imprint mold having this photo-curing reaction control film, a photosensitive resin pattern having no photo-curing resin residual film can be formed. As described above, various dry etching and wet chemical etching of a substrate (printed member) can be performed. Can be done.

  Example 1 will be described with reference to FIG. As shown in FIG. 3A, a photocuring reaction control polymer film 11 is provided on the surface of the convex portion of the imprint mold 1. Artificial quartz or sapphire is used for the mold base substrate 1. The photocuring reaction control polymer film 11 is composed of a functional polymer film such as a blocking film for light having a wavelength of a light source used for the photocuring reaction or an absorption film. In Example 1, the etching resist film used for the etching process of the mold is made of a material capable of blocking or absorbing ultraviolet rays, and this resist film is used as it is as a control film without being peeled off. Examples of functional materials that can block ultraviolet rays include cerium oxide, zinc oxide, and titanium oxide. Nanoparticles of these materials (particle diameter 50-100 nmφ) are dispersed and blended into the etching resist film. Examples of the photosensitive resin in which these nanoparticles are dispersed include, for example, a high-sensitivity negative far ultraviolet photosensitive resin (Deep UV / wavelength 250 to 300 nm), polyglycidyl methacrylate methylmaleic acid-adduct, chloromethylated polystyrene, A type of polymethyl isopropenyl ketone or polymethyl methacrylate is used. The photosensitive resin in which the light-blocking nanoparticles are dispersed is applied onto artificial quartz, sapphire or the like that is the material of the imprint mold 1, and then a photosensitive resin pattern that becomes an etching resist film by exposure and development is formed. Form. Thereafter, when the artificial quartz and sapphire are wet-chemically etched with a hydrofluoric acid aqueous solution, for example, the imprint mold 1 having a photocuring reaction control polymer film capable of blocking ultraviolet rays is completed.

  The imprint mold 1 having this photo-curing reaction control polymer film is aligned with a substrate (printed member) 2 coated with a photo-curing photosensitive resin 7 for pattern formation and pressed while being pressed ( FIG. 3 (b)). As the photosensitive resin for pattern formation, negative 2,6- (4'-azidobenzal) methylcyclohexanone (exposure wavelength 365 nm) having a resolution of 2 to 4 [mu] m and resistant to wet chemical etching can be used. In the imprint mold having the photocuring reaction control polymer film, the photocuring reaction does not proceed in the photosensitive resin 7 immediately below the photocuring reaction control polymer film. Accordingly, since the remaining film remaining uncured is soluble in an organic solvent or an aqueous solvent, the photo-curing resin pattern 8 appears by simple solvent cleaning immediately after the mold is peeled off (FIG. 3C). When the substrate (member to be printed) 2 is etched by wet chemical etching using the photocurable resin pattern as a resist, the etching pattern 10 is completed (FIG. 3D).

Examples of the substrate (non-printing member) 2 in this case include a printed circuit board for mounting a semiconductor device using a copper foil (5 to 20 μm thick) as a wiring conductor. Among printed circuit boards, in particular, module boards require fine wiring conductors having a wiring width of 5 to 10 μm in order to directly mount semiconductor elements (bare chips) on the module board. An aqueous solution of cupric chloride or ferric chloride is usually used for etching the copper foil. After the etching is completed, the photocurable resin pattern 8 is peeled off to complete the module substrate.
Other application examples include a microchemical chip using a glass substrate and a microbiochemical chip for DNA analysis. These microchips require a microchannel chip having a flow path of several tens of μm so that a very small amount of sample can be analyzed in a short time. Also in the case of this microchip, by using a photo-curing reaction control type imprint mold, a photosensitive resin pattern without a photo-curing resin residual film can be formed on a glass substrate, and dry chemical etching using CF ₄ or hydrofluoric acid Fine grooves can be formed in the glass substrate by wet chemical etching using an aqueous solution.

  A second embodiment will be described with reference to FIG. In Example 2, a polymer mold 1 b is used as the imprint mold 1. A photocuring reaction control polymer film 11 is formed on the polymer mold 1b using a photosensitive resin having a light blocking function. The photosensitive resin having a light blocking function is a negative-type photosensitive resist polyglycidyl methacrylate-methylmaleic acid-imparted product in which nanoparticles such as cerium oxide, zinc oxide, and titanium oxide described in Example 1 are dispersed and blended. Chlormethylated polystyrene, positive polymethylisopropenyl ketone, polymethyl methacrylate, or the like is used. The photosensitive resin is applied on a mold base substrate 1a such as quartz, sapphire, or polycarbonate, and then a polymer mold 1b is formed by exposure and development of the photosensitive resin using a photomask. In this polymer mold, a non-photosensitive resin can also be used. In this case, the photocuring reaction control polymer film 11 is formed by an excimer laser, a carbon dioxide gas laser, or the like. For non-photosensitive resins, nanoparticles of cerium oxide, zinc oxide, and titanium oxide may be dispersed and blended, but benzophenone-based resins and malonic ester-based resins that themselves absorb ultraviolet rays and have an ultraviolet blocking function Can also be used.

The thickness of the photocuring reaction control polymer film 11 is determined by the thickness of the photosensitive resin or non-photosensitive resin that is first applied on the mold base substrate 1a. When the polymer mold 1b is aligned with the substrate (printed member) 2 coated with the photocurable photosensitive resin and pressed while pressing (FIG. 4B), the polymer mold 1b is directly under the photocurable reaction control polymer film. The photo-curing reaction does not proceed with the photosensitive resin. Therefore, since the remaining film remaining uncured is soluble in an aqueous solvent or an organic solvent, the photo-curing resin pattern 8 appears by simple cleaning immediately after the mold is peeled (FIG. 4C). The photocuring resin pattern 8 is used as an etching resist film, the substrate (non-printing member) 2 is etched by various dry etching or wet chemical etching, and finally the photocuring resin pattern 8 is peeled to complete the etching pattern 10 (FIG. 4 (d)).
Examples of the application of the polymer mold include a module substrate, a microchemical chip, and a microbiochemical chip as in the first embodiment.

A third embodiment will be described with reference to FIG. In Example 3, a photocuring reaction control inorganic film 12 (hereinafter simply referred to as an inorganic film) on the mold base substrate 1a is used as the photocuring reaction control film. As the inorganic film, for example, a chromium vapor deposition film of a metal mask used for photolithography, an electroless plating film such as nickel, or a ceramic film such as chromium oxide is used. Artificial quartz, sapphire, or the like is used for the mold base substrate 1a, and the photocuring reaction controlled inorganic film 12 is formed thereon. The pattern of the inorganic film can be formed by a normal photolithography method after the entire surface is deposited on the base substrate or after the entire electroless plating. In the case of forming by electroplating such as copper, nickel, or chromium, first, a vapor deposition thin film such as copper, nickel, or chromium is formed on the entire surface of the mold base substrate 1a. Thereafter, a plating resist pattern by exposure and development of a photosensitive resin is formed on the deposited thin film using a photomask. Next, electroplating with a required thickness is performed. Finally, the copper film deposited immediately below the plating resist pattern and the electroplating resist is peeled off to form the photocuring reaction controlled inorganic film 12, thereby completing the inorganic film mold 1c. By using the imprint mold having the photocuring reaction controlled inorganic film, a photosensitive resin pattern without a photocuring resin residual film can be formed. As described above, various dry etching and wet chemicals for the substrate (printed member) 2 can be performed. Etching can be performed. Applications of the polymer mold include a module substrate, a microchemical chip, and a microbiochemical chip as in the first and second embodiments.

A fourth embodiment will be described with reference to FIG. Example 4 is a method using a polymer mold created by using a master mold manufactured by an EB processing method or the like for forming a finer pattern. In this method, as shown in FIG. 2, an ultraviolet transmissive artificial quartz, sapphire, or the like is used for the substrate (member to be printed) 2. When a photo-curable photosensitive resin film capable of blocking ultraviolet rays is formed on the substrate 2 as in Examples 2 and 3, and the imprint mold 1 is used as a master mold and irradiated with ultraviolet rays, the sub mold relative to the master mold is formed. A master version (replica version) is produced (FIG. 1 (d)). In this method, a photo-curing resin residual film 9 is formed as shown in FIG. The photocured resin residual film 9 is removed by dry chemical etching using CF ₄ or the like while considering the gas pressure and time so that the photosensitive resin pattern 8 is not reduced to a predetermined thickness or less. However, when the master mold has a photocuring reaction control film as in Example 1 (FIG. 3), it is not necessary to remove the photocuring resin residual film.
In this method, since a master mold is created by EB processing, a very fine pattern of 50 nm to 1 μm can be formed. By using the polymer mold having the photocuring reaction control polymer film thus prepared, the photocuring resin pattern 8 having no photocuring resin residual film can be formed on the substrate (printed member) 2. (Printed member) 2 can be etched by dry etching or wet chemical etching.
An application of this method is a magneto-optical disk such as a large-capacity MO. A large capacity MO is expected to require a 100 GB recording medium in the future. For this purpose, a dot pattern of 50 nm is required on a 3-inch disk, but inexpensive production in mass production of MO having this dot pattern is impossible by EB direct drawing using an expensive EB processing apparatus, As described in the prior art, the photocuring reaction control type imprint mold in the present invention is required.

The invention's effect

The effect of the present invention is the technical problem of the optical imprint mold mentioned in the problem to be solved by the invention 1) Eliminating the residual resin film after light irradiation.
2) To reduce the size of the imprint apparatus.
3) To enable finer pattern formation.
4) To shorten the imprint process and reduce the cost of the final imprint applied product by reducing the process.
As well as
5) By using the sub master plate, it is not necessary to use many expensive master plates by EB processing, and large capacity media disks such as MO can be made at low cost.
There are many effects such as.

Imprint device Conventional imprint mold Imprint mold of the present invention Imprint mold of the present invention Imprint mold of the present invention

Explanation of symbols

  1 imprint mold, 1a mold base substrate, 1b polymer mold, 1c inorganic film mold, 2 substrate (printed member), 3 sapphire (ultraviolet irradiation plate), 4 stage, 5 optical fiber, 6 stage up arrow 7 Photo-curing type photosensitive resin, 8 Photo-curing resin pattern, 9 Photo-curing resin residual film, 10 Etching pattern, 11 Photo-curing reaction control polymer film, 12 Photo-curing reaction control inorganic film

Claims (3)

  Resin film, inorganic film, etc. for controlling photo-curing reaction in photo-curable imprint mold using light-transmitting artificial quartz, sapphire, polycarbonate, etc. A photo-curing reaction control type imprint mold, an imprint processing method using the same, and an imprint processed product.   The resin film or inorganic film for controlling the photocuring reaction according to claim 1 is a functional film such as a reflection or absorption film that can block the irradiation light of the photocuring reaction. The photocuring reaction control type imprint mold described above, an imprint processing method using the same, and an imprint processed product.   In claim 1, the imprint processed product is a printed circuit board on which a semiconductor chip, a semiconductor device, an electronic device or the like is mounted, a micro biochemical chip used for DNA analysis, a micro chemical chip used for chemical reaction analysis, or the like. An imprint processed product produced using the photocuring reaction control type imprint mold according to claim 1.

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