JP2009172766A - Method for duplicating molecular pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for duplicating a molecular pattern, by which duplicated products with a hyperfine line width can be mass-produced in a short time. <P>SOLUTION: The method for duplicating a molecular pattern includes steps of: forming a resist pattern on a surface of a substrate 1 where a hydrophilic silicon oxide film or a metal oxide film is formed, and chemically modifying the substrate surface with a hydrophilic silane coupling agent so as to form a hydrophilic pattern having a hydrophilic surface; removing the resist pattern; consecutively, chemically modifying the substrate surface with a lipophilic silane coupling agent to form a lipophilic surface so as to form the substrate surface having a surface where single molecules in a predetermined polarity are arranged in a pattern and a surface having a different polarity in a similar molecular level, in accordance with the lipophilic surface and the hydrophilic surface; mounting a transfer layer 5 comprising polar molecules having the same polarity as a predetermined polarity on the substrate surface so as to form a predetermined pattern only in a part where the polarities are the same; and bringing a transfer object into contact with the substrate surface to transfer the predetermined pattern comprising the transfer layer 5 onto the transfer object. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for replicating an ultrafine molecular pattern in a molecular device or the like.

  In 1982, the concept of molecular devices was L. Since it was proposed by Carter, research and development in this field has become increasingly active. If a function is given to each organic molecule and its aggregate is formed, for example, an ultra-high density semiconductor device that is not comparable to the degree of integration so far can be formed.

  The LB (Langmuir-Blodget) method is promising as one technique for producing this molecular device. This LB method is a method in which an amphiphilic compound composed of a hydrophilic group and a hydrophobic group is developed on a water surface to form a monomolecular film, and the monomolecular film is directly copied onto a support. Since the film thus prepared is array-controlled in a two-dimensional plane, a function not found in each molecule can be expressed.

  On the other hand, there are a printing method and a lithography method as a conventional representative pattern copying technique. The former is a method of placing ink on a plate and copying the ink on paper or the like. The latter is generally used for manufacturing semiconductor devices, etc., and a substrate having an original pattern by exposing a processed substrate through a master called a mask and exposing a photosensitive polymer (resist) to the substrate to be processed by etching. Is mass-replicated.

  In particular, when replicating a fine pattern, the minimum processing line width by the lithography method depends on the wavelength of the irradiated ionizing radiation. That is, if the wavelength of ionizing radiation is shortened, the processing line width is reduced.

  At present, a reduction projection exposure apparatus called a stepper is used for manufacturing a semiconductor, whereby a mask pattern is reproduced in large quantities. The light source used here is an ultraviolet ray of a mercury lamp, and the minimum processing line width is about 0.3 μm. Furthermore, when finer processing is required, processing of about several tens of nanometers can be performed using an electron beam.

  However, the lithography method has a limit in terms of manufacturing a large number of replicated products in a short time because a substrate having a predetermined pattern is replicated by taking several steps for each sheet.

  Further, the lithography process has a problem that a complicated process (equipment) such as exposure, development, and etching is required.

  The present invention has been made in view of the above-described problems. From a polar molecule that matches (affinity) or does not match (non-affinity) the polarity to a substrate surface on which single molecules of a predetermined polarity are arranged in a pattern. A transfer method comprising: forming a predetermined pattern by placing a transfer layer on the substrate, and then transferring the pattern made of the transfer layer to the transfer target by bringing the transfer target into contact with the surface of the substrate. .

  That is, in the present invention, first, a plate having a desired pattern is prepared, and a molecular film (transfer layer) to be transferred is placed thereon. At this time, since the surface of the plate has a different polarity, a molecular film (an ink component, a conductive molecule, etc.) is attached only to a portion that matches the polarity of the binding molecule (that is, a portion having an affinity for each other). This is a method in which a product such as a substrate having a molecular level pattern is duplicated by pressing this onto another transferred material and the molecules adhering (transferred) to the other transferred material. According to the present invention, it is possible to transfer a molecular pattern having no polymerization functional group, and it is possible to replicate a pattern with an ultrafine line width below the resolution limit of light in large quantities.

It is process sectional drawing which shows one Example of the molecular pattern replication method of this invention. It is explanatory drawing which shows the chemical modification process of the surface of the plate used for the molecular pattern replication method of this invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings.
First, plates having surfaces with different polarities are prepared. As a method of making a plate, a metal or resist pattern is formed by a normal lithography process on a substrate 1 having a metal oxide layer 2 having a hydrophilic surface on the uppermost surface. Next, the patterned substrate is immersed in the silane coupling agent solution and dried by heating at a temperature of 40 to 100 degrees. The excess silane coupling agent is then washed away with a solvent and dried. Finally, by removing the metal or resist pattern with a metal etchant or resist stripping solution, a PS plate comprising a hydrophilic oxide surface 3 and a lipophilic silane-coupled surface 4 is obtained.

  Furthermore, if the hydrophilic surface is chemically modified with a silane coupling agent having a different polarity (hydrophilic), a substrate having a surface with a different polarity at almost the same level can be obtained (shown in FIG. 1A). On the contrary, it is of course possible to first chemically modify the substrate surface excluding the resist pattern with a hydrophilic coupling agent, and then remove the resist pattern and chemically modify with a lipophilic coupling agent.

  The above-mentioned chemical modifiers are not limited to silane coupling agents, but differ in surface energy by bonding chemically modified molecules that can react with the chemical modification sites to form bonds on a substrate having a chemical modification site on the surface. Any material that can form a surface may be used.

  Further, a PS plate having a diazonaphthoquinone photosensitizer used in conventional printing may be used, but a plate prepared by using the above-described chemical modification having excellent resolution is preferable.

As the silane coupling agent used in the present invention, those having O (CH ₃ ) _n (n = 1 to 3), OCl, OBr, and O in the molecule are preferable. This silane coupling agent is chemically modified on the substrate surface as shown in FIG. If a polymer is used for the silane coupling agent, the bond with the substrate becomes stronger.

  Next, a molecular film (ink component, conductive molecule, etc.) 5 to be transferred prepared in advance on the plate thus prepared is placed on the substrate surface. At this time, since the surface of the plate has different polar surfaces, the molecular film adheres only to a portion (transfer pattern surface) having the same polarity (FIG. 1B). Next, the molecular film 5 adheres to the transfer body in the form of a transfer pattern by pressing it against the transfer body 6 to complete the transfer (FIGS. 1C and 1D).

  The molecular film 5 (transfer layer) used in the present invention may be composed of any polar molecule, but a regularly arranged film such as an LB (Langmuir-Blodget) film is desirable for producing a molecular device. As a method of placing the molecular film 5 on the plate, there is an LB method or a horizontal adhesion method in which a monomolecular film on the water surface is copied as described above. In addition, there are a spin coating method, an immersion method, an OMBE (organic molecular beam epitaxy) method, a vapor deposition method, and a CVD method.

  Hereinafter, the present invention will be described in more detail with reference to an example of the molecular pattern replication method of the present invention.

  A chromium film was formed on a quartz substrate by a 30 nm sputtering method, an EB resist was applied, irradiated with an electron beam, and a 0.1 μm line & space chromium pattern was formed through a development process and an etching process. Next, the substrate was immersed in a lipophilic silane coupling agent (octadecyltrimethoxysilane: solvent toluene) for 5 minutes at room temperature. Next, it was dried by heating at a temperature of 70 degrees for 15 minutes. Next, the chromium pattern was peeled off with a chromium etchant, and then the substrate was immersed in a oleaginous silane coupling agent (solvent 1,3-bistrifluoromethylbenzene) at room temperature for 5 minutes. Next, it was dried by heating at a temperature of 70 degrees for 15 minutes. As a result, a plate having an oil surface and a lipophilic surface was completed. The pattern was confirmed by measuring the difference in friction force of this plate with FFM (friction force microscope).

Subsequently, stearic acid dissolved in a chloroform solution was spread on the water surface and compressed to prepare a monomolecular film, and this monomolecular film was accumulated in two layers on the plate using the LB method at a surface pressure of 30 mN / cm ² . Next, a carbon support was pressed against the plate on which the monomolecular film was formed, and the pattern was replicated by transferring the monomolecular film to the support. This pattern was confirmed by AFM (atomic force microscope).

  In this example, a large number of replicas having a fine pattern with a minimum line width of about 90 nm could be produced. As a result, mass replication on the order of nanometers becomes possible, making it possible to manufacture highly integrated memories, devices, and the like.

1 Substrate 2 Oxide layer 3 Lipophilic molecule (surface)
4 Hydrophilic molecules (surface)
5 Molecular film 6 Transferee

Claims (5)

  A resist pattern is formed on the substrate surface on which a hydrophilic silicon oxide film or a metal oxide layer is formed, and a hydrophilic pattern having a hydrophilic surface is formed by chemically modifying the substrate surface with a hydrophilic silane coupling agent. A step of removing the resist pattern, and then chemically modifying a lipophilic silane coupling agent on the surface of the substrate to form a lipophilic surface, and the lipophilic surface and the hydrophilic surface have a predetermined polarity. A step of forming the surface of the substrate having a surface on which single molecules are arranged in a pattern and a surface having different polarities at substantially the same level as the surface, and then transferring the polar molecule that matches the predetermined polarity on the substrate surface A step of forming a predetermined pattern only on a portion where the layers have the same polarity by placing the layer, and then bringing the transferred body into contact with the substrate surface Characterized by comprising the step of transferring the predetermined pattern of layers to the transfer object, molecular patterns replication method.   The molecular pattern replication method according to claim 1, wherein the transfer layer is prepared by an LB method or a horizontal adhesion method.   The molecular pattern replication method according to claim 1, wherein the transfer layer is prepared by a spin coating method.   The molecular pattern replication method according to claim 1, wherein the transfer layer is prepared by an immersion method.   The molecular pattern replication method according to claim 1, wherein a minimum line width of the transferred pattern is about 90 nm.

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