JP5462113B2 - ELECTRODE BODY HAVING CIRCUIT PATTERN AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Description

  The present invention relates to an electrode body having an arbitrary circuit pattern and a manufacturing method thereof.

  Conventionally, a photolithography process and an etching process have been used as a “pattern formation method” for forming an arbitrary conductive film pattern (hereinafter referred to as a “circuit pattern” in this specification) on a substrate such as a film or a substrate. A circuit pattern forming method is known. In this method, after a conductive film is formed on a substrate, a photoresist film is applied thereon, exposure and development are performed to form a pattern, and then the pattern is transferred to the conductive film through an etching process. The photoresist film is removed.

  Such a circuit pattern forming method can be applied to various fields. For example, a transparent conductive film such as indium tin oxide (ITO) is formed on a transparent film, and the pattern is formed by the above-described method. A method of forming a “transparent electrode body” used for a transparent touch panel or the like is known (Patent Document 1).

  As another method for forming a fine pattern on a conductive film, a method has been proposed in which unnecessary portions of a transparent conductive film deposited on a substrate are removed by etching with an electric current (Patent Document 2). .

  As another method of forming a circuit pattern, scanning is performed with a voltage applied to a probe of a scanning tunneling microscope (STM) or an atomic force microscope (AFM) to partially apply an oxide film (this is referred to as “electric field”). A method of forming a circuit pattern by removing an oxide film by etching after it is formed, and a pattern formed by a photolithography process on a conductive film having a property of forming an insulating layer by irradiation with ultraviolet rays such as polysilane. Various methods have been proposed such as a method of forming a circuit pattern by irradiating the entire surface with ultraviolet rays after forming and forming an insulating layer on the irradiated portions (Patent Documents 3-5, etc.).

APPLIED PHYSICS LETTERS 93, 042106 (2008)

JP 2001-291445 A JP-A-4-113321 Japanese Patent Laid-Open No. 11-283937 JP-A-6-291273 JP-A-55-76505

  However, the conventional circuit pattern forming method involving a photolithography process and an etching process has a problem that the number of processes is large and an expensive photomask must be used. In addition, since a pattern is formed by an optical lens or the like during the exposure process, it is theoretically difficult to form a fine circuit pattern that is less than the resolution limit of the optical lens.

  Further, FIG. 13 shows a state in which a circuit pattern is formed by a photolithography process and an etching process after the conductive film 230 is formed on the substrate 210. As shown in FIG. In the case of the pattern forming method, there is a problem that a “step” is formed by etching in the conductive film. For this reason, especially when obtaining a transparent electrode body using a transparent conductive film, the optical characteristics are likely to be non-uniform due to the presence or absence of the transparent conductive film. This causes a decrease in performance as a transparent electrode body.

  The present invention has been made in view of the above-described problems, and a main technical problem is to form a very fine conductive film pattern without performing an etching process by a simpler technique than before.

In the method for producing an electrode body according to the present invention, an electrode is brought into contact with or close to a predetermined distance on the metal oxide film on the substrate having a laminated film on the surface of which a conductive film and a metal oxide film are formed in this order, in this state, locally changing the resistivity of the previous SL electrode and said metal oxide film wherein changing the relative position of the metal oxide film together when a voltage is applied between the conductive film and the electrode A circuit pattern forming step, wherein the voltage generates an electric field necessary and sufficient to move oxygen contained in the metal oxide film as oxygen ions. It is characterized by.

  With such a configuration, a circuit pattern having the same width as the electrode can be obtained. If a fine needle-like electrode is used, for example, a thin line pattern of 10 nm or less that is difficult in a conventional photolithography process can be obtained.

This principle is explained as follows. It is known that a metal oxide film exhibits a reversible resistance change when a voltage is applied. In order to explain this phenomenon, an “redox model” has been proposed. According to this, when a voltage (DC voltage or pulse voltage) is applied to the metal oxide film, oxygen atoms contained in the metal oxide film move in the form of oxygen ions (O ²⁻ ), thereby causing the inside of the metal oxide film. A minute oxygen defect region (this is referred to as a “filament” in this specification) is formed. A filament is a path formed by continuous oxygen vacancies, and when viewed microscopically, it is considered that this filament can form a current path (conduction path) in the metal oxide film. That is, in the portion where the filament is formed, the carrier concentration increases due to the introduction of oxygen vacancies, resulting in a low resistance state locally. On the other hand, when a voltage is applied to the metal oxide film in a low resistance state, oxygen vacancies are gradually repaired, so that the carrier concentration is lowered, and the reverse phenomenon occurs. That is, the defect generation and repair phenomenon due to the movement of oxygen ions is considered as the oxidation and reduction phenomenon of the filament. As shown in the embodiments described later, various metal oxide films including nickel oxide and zinc oxide (particularly binary transition metal oxide films and magnesium, zinc, indium, tin, aluminum, etc. It has been confirmed that it is expressed in a metal oxide film).

  For convenience, in this specification, a state in which a negative voltage is applied to the electrode is referred to as a reset state (high resistance state), and conversely, a state in which a positive voltage is applied is referred to as a set state (low resistance state). However, the positive / negative relationship may be reversed.

1 4, manganite current before and after the application of positive and negative pulses (manganese oxides) - is a graph showing the results of measurement of the voltage characteristic (I-V characteristic). The IV characteristics are measured by repeatedly applying a negative pulse voltage of −3.2 V and a 100 ns rectangular pulse and a positive pulse voltage of +3.2 V and a 100 ns rectangular pulse. It can be seen that the electrical resistance decreases when a positive pulse voltage is repeatedly applied, and the electrical resistance increases when a negative pulse voltage is repeatedly applied.

  That is, when a negative pulse voltage is applied from a state in which a positive pulse is repeatedly applied (set state), the current value decreases and finally a transition is made to a reset state. On the other hand, when a positive pulse is applied to the metal oxide film in the reset state, it gradually shifts to the set state. Even after writing once, the resistance state can be arbitrarily rewritten by applying a positive or negative pulse voltage. It is clear that the set state and the reset state are reversible, and unless the voltage is applied, the resistance value does not change and exhibits non-volatility. In this manner, a nonvolatile multi-level memory operates by applying a pulse voltage to the metal oxide film to change the resistance state. However, the DC voltage is in a state in which the pulse width of the pulse voltage is infinite, and when a positive or negative DC voltage is applied, a binary value of a low resistance state (set state) and a high resistance state (reset state) Become. The number of rewrites when operating as a memory is said to be 10 6 or more times, which is the number of rewrites that exceeds the flash memory by about one digit. The writing speed is determined by the pulse width and the number of pulses, but it is considered that the writing operation is completed much faster than hot electron injection into the floating gate like a flash memory.

  However, in the method of manufacturing the electrode body according to the present invention, since the write operation is required at least once when forming the circuit pattern, the metal oxide film before writing the circuit pattern is in a high resistance state. If a positive DC voltage is applied to the electrodes and scanning is performed, a circuit pattern in a low resistance state is formed. However, even in such a case, the specific resistance of the metal oxide film may be once lowered over the entire region where the circuit pattern is formed, and then the portion other than the circuit pattern may be raised. The reason for this is that when the state is changed from low resistance to high resistance, a voltage is likely to be applied to the electrode 40 and the contact surface of the electrode.

  The voltage application method is not necessarily a pulse voltage. The inventors of the present invention have confirmed through experiments that a write operation can be performed using either direct current or pulse. In the case of Ga-doped ZnO (thickness: 200 nm), it has been confirmed that when a rectangular pulse having a wave height of 2 V and a pulse width of 5 μs is repeatedly applied, a resistance change with a high resistance / low resistance ratio of about 10 occurs. It has been confirmed that a resistance change of about 20 times occurs when writing with a DC voltage of 2 volts. In both cases of direct current and pulse, the resistance change that occurs increases as the applied voltage is increased or the voltage sweep speed is decreased (in the case of a pulse, the pulse width is increased). In addition, in the case of direct current or pulse writing, even if the same voltage or pulse height is used, the applied voltage is varied by connecting resistors in series with the electrodes when the voltage is applied, or the current generated by active elements such as transistors and diodes. The resistance value to be written can be controlled by inserting a limiting circuit in series or controlling the amount of current passing through the metal oxide film when a voltage is applied.

  The metal oxide film is nickel oxide, titanium oxide, tantalum oxide, hafnium oxide, zirconium oxide, yttrium oxide, cerium oxide, magnesium oxide, zinc oxide, indium oxide, tin oxide. , Tungsten oxide, niobium oxide, chromium oxide, manganese oxide, aluminum oxide, vanadium oxide, cobalt oxide, or copper oxide (copper oxide (I) or copper oxide (II)) It is preferable that any one of them is a main component. Note that “main component” means that the composition is not necessarily limited to the stoichiometric composition.

Note that some types of metal oxide films are in a low resistance state immediately after film formation. Impurity doped metal oxide film, for example, zinc oxide (ZnO) or indium tin oxide (ITO) doped with impurities such as Ga, Al and In, Nb doped titanium oxide (TiO ₂ ), Nb doped Strontium titanate (SrTiO ₃ ) and the like are in a low resistance state immediately after film formation. In the case of such a metal oxide film, the step of reducing the resistance over the entire area where the circuit pattern is to be formed can be omitted, and scanning is performed by applying a negative DC voltage or a pulse voltage so that the scanned portion is a high resistance area. It can also be. In this case, as described above, regions having different specific resistances can be locally formed in the circuit pattern using resistors and active elements.

However, when only two states of high resistance and low resistance are maintained, it is preferable that the metal oxide film is not added with impurities. Note that the “impurity” herein refers to a substance that has an effect of supplementing the carrier concentration due to oxygen deficiency. For example, in an experiment using zinc oxide added with gallium as a metal oxide film, it has been clarified that the state change to the reset state becomes gradual. The reason for this is explained as follows. When the gallium-doped zinc oxide is described by a chemical formula, it is (Zn _1-x Ga _x ) O _1-δ . The transition process to the reset state means that δ approaches 0, that is, a process in which oxygen deficiency is repaired. For this reason, as the oxygen deficiency concentration decreases, the amount of current also decreases and Joule heat decreases. Since the Joule heat decreases rapidly in inverse proportion to the square of the current value, the reset operation proceeds rapidly when no impurity is added. However, when impurities are added to the metal oxide film, it is considered that the added impurities become residual carriers, and the transition from the set state to the reset state proceeds slowly. When a memory element, a resistance element, or the like is manufactured in a circuit, it is necessary to finely adjust the resistance value, and impurities may be added as necessary.

  In this way, when the impurity which becomes a residual carrier is added and the transition to the reset state becomes gentle, the change particularly in the high resistance value region becomes small.

Zinc oxide doped with gallium: Combined transition by applying a negative voltage to the (Ga ZnO) from the set state to the reset state, that slowly turn into higher resistance than without the addition of impurities (gallium).

  Therefore, for example, in the case of applying to a nonvolatile memory using the state change of the resistance value, there may be an advantage that multi-value can be obtained by storing a large number of states. In the case of application, it is rather advantageous to reduce the residual carriers and make the change to the reset state side abruptly.

  The electrode may be a conductive probe (cantilever) used in a conductive atomic force microscope (C-AFM). The AFM has modes such as a contact mode, a non-contact mode, and a tapping mode. Since the AFM is used not for observing the surface shape but for forming a circuit pattern, the tip of the probe and the lower electrode (that is, It does not matter whether or not the tip of the electrode is in contact with the metal oxide as long as an electric field sufficient to generate oxygen vacancies can be generated between the conductive film and the metal oxide film below the metal oxide film.

  Further, depending on the shape of the target circuit pattern, a large number of the electrodes may be arranged in a comb shape. For example, such a comb-like electrode is preferable for forming a row electrode or a column electrode of a touch panel. A light adhesion layer may be formed between the base and the laminated film or between the conductive film and the metal oxide film in the laminated film. The light adhesion layer may be configured to have conductivity, and a circuit pattern may be formed by applying a voltage between the light adhesion layer and the electrode. Further, the base is composed of a transparent member that transmits ultraviolet rays, and the conductive film is composed of a member that increases resistance by ultraviolet irradiation. After the step of forming a circuit pattern, the conductive layer is applied to the conductive film from the base side. On the other hand, you may have further the process of irradiating an ultraviolet-ray. An organic conductive polymer can be used for the member whose resistance is increased by the ultraviolet irradiation.

  In the first electrode body according to the present invention, a metal oxide is laminated on a base via an adhesive layer, and the metal oxide film has a relatively high specific resistance within a metal oxide film having a relatively high specific resistance. A circuit pattern composed of a low area is formed.

  The second electrode body according to the present invention is formed by laminating an organic polymer film and a metal oxide film on a substrate, and the metal oxide film is relatively placed in a metal oxide film having a relatively high specific resistance. A circuit pattern comprising a region having a low specific resistance is formed, and the organic polymer film is formed of an insulator. In this case, the sheet resistance value of the organic polymer film is preferably at least 100 MΩ / □.

  Both the first and second electrode bodies can be manufactured by the method for manufacturing an electrode body according to the present invention, the surface of the metal oxide film on which the electrode pattern is formed is flush, and optical The mechanical characteristics are almost uniform. These electrode bodies can be used for applications such as a touch panel by constituting the substrate with a transparent member.

  According to the method of manufacturing an electrode body according to the present invention, an electrode body having an ultrafine pattern that is difficult in a photolithography process can be obtained. In addition, since the circuit pattern is formed in the metal oxide film, the surface of the circuit pattern is a flat surface. Therefore, when the metal oxide film is made of a transparent member, there is an advantage that the optical characteristics become uniform.

Schematic diagram of the structure of the electrode body as the first embodiment (a) sectional view, FIG. 1 (b) perspective view (A)-(d) is process sectional drawing corresponding to step Sa1-Sa4 of FIG. (E)-(i) is process sectional drawing corresponding to step Sa5-Sa9 of FIG. The figure which shows the manufacture procedure of the electrode body of the structure of FIG. Schematic of the structure of an electrode body as a third embodiment (a) sectional view, (b) perspective view (A)-(d) is process sectional drawing corresponding to step Sb1-Sb4 of FIG. (E)-(f) is process sectional drawing corresponding to step Sa5-Sa6 of FIG. The figure which shows the manufacturing procedure of the electrode body of a structure of FIG. Configuration diagram of matrix resistance touch panel (a) Plan view (b) Cross section taken along line X1-X1 Configuration diagram of projected capacitive touch panel (a) Plan view, (b) X2-X2 cross-sectional view Configuration diagram of matrix resistance type touch panel (a) Plan view (b) Y1-Y1 cross-sectional view Configuration diagram of projected capacitive touch panel (a) Plan view, (b) Y2-Y2 cross-sectional view Conventional circuit pattern formed by photolithography process and etching process Ma Nganaito before and after applying positive and negative pulses in the current - shows the results of measurement of the voltage characteristic (IV characteristic)

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, all of these embodiments are illustrative and do not give a limited interpretation of the present invention. In addition, in drawing, the same code | symbol shall be attached | subjected about the same or corresponding part.

First Embodiment-Structure of Electrode Body 1-
FIG. 1 is a diagram schematically showing a structure of an electrode body as a first embodiment. 1A is a cross-sectional view, and FIG. 1B is a perspective view.

  The electrode body 10 shown in FIG. 1 shows a state in which a metal oxide film 23 is formed on the surface of a base 27 via an adhesive layer 26. The adhesive layer 26 is a layer for fixing the base 27 and the metal oxide film 23 while being insulated and separated, and is a thin layer obtained by applying an adhesive. If the electrode body and the substrate can be joined without using an adhesive, the adhesive layer 26 is unnecessary.

  The metal oxide film 23 is formed with a line and space composed of a region having a relatively high electrical resistance (high resistance region 23a) and a region having a relatively low electrical resistance (low resistance region 23b). . The high resistance region 23a and the low resistance region 23b are electrically different in resistance value, but both have the same composition and almost the same optical characteristics (reflectance, transmittance, refractive index, etc.). .

  Metal oxide thin films generally have the property of changing electrical resistance when a voltage is applied. Specifically, materials having such properties include nickel oxide, titanium oxide, tantalum oxide, hafnium oxide, zirconium oxide, yttrium oxide, cerium oxide, magnesium oxide, zinc oxide, Indium oxide, tin oxide, tungsten oxide, niobium oxide, chromium oxide, manganese oxide, aluminum oxide, vanadium oxide, cobalt oxide, or copper oxide (copper oxide (I) or copper oxide ( II)), and a metal oxide film containing as a main component any of them.

  However, it is not necessarily limited to the stoichiometric composition, and some impurities may be contained. Note that these metal oxide films are classified into a low resistance state and a high resistance state immediately after film formation, and can be brought into a low resistance state by adding impurities. For this reason, a circuit pattern is formed by applying a voltage to a metal oxide film in a high resistance state to form a low resistance region to form a circuit pattern, and applying a voltage to the metal oxide film in a low resistance state. Can be applied to form a high resistance region in a portion excluding the circuit pattern formation region.

  As described above, a low-resistance region 23b is formed in the metal oxide film 23, which is the high-resistance region 23a, by locally forming a filament-shaped current path inside the metal oxide film 23. The low resistance region 23b functions as a wiring as a circuit pattern. The resistance change is considered to occur in the filament, and since the shape of the filament is unclear, it is difficult to directly measure the resistivity, but the resistance ratio between the high resistance region 23a and the low resistance region 23b is at least 10 times or more.

  The base body 27 is, for example, an insulating film and plays a role of fixing the electrode body 10. For example, when the electrode body 10 is used as a transparent electrode of a touch panel, the base body 27 needs to be transparent. On the other hand, when it is used simply as an electrode body having a fine circuit pattern, it is not necessarily transparent. The substrate 27 may be made of any material such as a glass substrate, an oxide substrate, a plastic substrate, and a plastic film as long as the electrode body 10 can be fixed with an adhesive or the like.

  The electrode body 10 shown in FIG. 1 is in a state where the wiring is embedded in the insulating film, and since the surface is flat, the optical characteristics are almost uniform. Note that “the optical characteristics are uniform” means that the optical characteristics do not change between a low resistance region (a portion functioning as a wiring) and a high resistance portion (a portion functioning as an insulating film).

(Second Embodiment) -Electrode Body Manufacturing Method 1-
Next, the manufacturing method of the electrode body shown in the first embodiment will be described with reference to FIGS.

  FIG. 4 is a diagram showing a manufacturing procedure of the electrode body having the configuration shown in FIG. The manufacturing procedure is roughly divided into steps Sa1 to Sa9. 2A to 2D are process cross-sectional views corresponding to steps Sa1 to Sa4 in FIG. 4, and FIGS. 3E to 3I correspond to steps Sa5 to Sa9 in FIG. It is process sectional drawing corresponding.

  In the first step Sa1, a first base 21 for supporting the electrode body is prepared (FIG. 2 (a)). As the substrate 21, a glass substrate, an oxide substrate, a plastic substrate, a plastic film, or the like can be used. For example, the substrate 21 is selected from indium tin oxide (ITO), zinc oxide (ZnO), titanium oxide (TiO 2) to which impurities are added, strontium titanate (STO) to which impurities are added, carbon (C), and the like. You may be comprised with the member. Alternatively, the substrate may be polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethersulfone (PES), polyetheretherketone (PEEK), polycarbonate (PC), polypropylene (PP), polyamide (PA), It may be a flexible resin film such as polyacrylic (PAC), epoxy resin, phenol resin, aliphatic cyclic polyolefin, norbornene-based thermoplastic transparent resin, or a film made of a laminate of two or more of these.

  The base 21 serves as a support member for forming an electrode body having a circuit pattern. However, since a circuit pattern is formed on the electrode body and then separated from the electrode body, even when a transparent electrode body is manufactured, it is not always necessary to be transparent. For example, the base 21 may be a metal or semiconductor substrate.

  In the next step Sa2, a light adhesion layer 25 is formed on the surface of the substrate 21 (FIG. 2B). The light adhesion layer 25 is made of, for example, wax, silicone, or the like, and has a function as a separation layer (peeling layer) for separating the upper layer and the lower layer (base 21 in this case). In some cases, the light adhesion layer 25 can be provided with conductivity and used as an electrode. In addition, step Sa2 which applies this wax or silicone may be replaced with the next step Sa3 (forming process of the conductive film 22).

  In the next step Sa3, the conductive film 22 is formed on the surface of the light adhesion layer 25 (FIG. 2C). The conductive film 22 includes iridium (Ir), platinum (Pt), ruthenium (Ru), rhodium (Rh), palladium (Pd), gold (Au), chromium (Cr), nickel (Ni), copper (Cu), Conductives such as single metals such as aluminum (Al) or alloys thereof, indium tin oxide (ITO), zinc oxide (ZnO), titanium oxide added niobium to titanium oxide (Nb: TiO2), etc. Any film may be used. Moreover, not only a metal but an organic conductive polymer, a carbon layer, etc. may be sufficient. The film formation method and the film thickness are not particularly limited, and a known film formation method and film formation conditions such as a sputtering method and a vacuum evaporation method can be used.

  In the next step Sa4, a metal oxide film 23 of, eg, a thickness of about 50 nm is formed on the surface of the conductive film 22 (FIG. 2D). The metal oxide film 23 is made of nickel oxide, titanium oxide, tantalum oxide, hafnium oxide, zirconium oxide, yttrium oxide, cerium oxide, magnesium oxide, zinc oxide, indium oxide, tin oxide. , Tungsten oxide, niobium oxide, chromium oxide, manganese oxide, aluminum oxide, vanadium oxide, cobalt oxide, or copper oxide (copper oxide (I) or copper oxide (II)) What has either one as a main component is preferable.

  As a condition when using the sputtering method, for example, when nickel oxide is formed, nickel oxidation is performed by sputtering with Ni as a target metal at a pressure of 0.1 Pa, a substrate temperature at room temperature in a mixed gas of oxygen and argon. Things can be formed.

  In the next step Sa5, a circuit pattern is formed by bringing the electrode 40 into contact with the surface of the metal oxide film 23 or bringing it close to a predetermined distance (FIG. 3E). The electrode 40 is connected to the power supply device 50, is configured to be able to apply a DC voltage between the conductive film 22 and the electrode 40, and is configured to be able to scan the electrode 40 with respect to the metal oxide film 23. Yes. As a device suitable for realizing this, specifically, a conductive atomic force microscope (C-AFM) capable of simultaneously measuring current and atomic force can be used. Instead of this, a scanning tunneling microscope (STM) or the like that measures tunneling current may be used. All of these use conductive cantilevers as electrodes, and are known as measuring devices that can obtain current images simultaneously with the uneven shape of the measurement object. By using these devices, metal oxides can be used. An extremely fine circuit pattern can be formed on the film.

  Note that the shape of the electrode 40 may be appropriately changed according to the circuit pattern to be created. For example, an electrode having a small tip diameter is used for a thin pattern, and a thick electrode is used for a thick pattern. In the case of forming a plurality of lines, needle-like electrodes may be arranged in a comb-like shape to increase manufacturing efficiency.

  In particular, the metal oxide film in a state before voltage application, that is, before the write operation is a low resistance film, and when the resistance is changed to high resistance by writing, a thick needle-like electrode is used or a large area of the electrode is used. It is considered possible to obtain a thick pattern or a wide area pattern at a time by bringing the electrodes into contact with each other. The reason for this is that when the state is changed from low resistance to high resistance, a voltage is likely to be applied to the electrode 40 and the contact surface of the electrode. The resistance change easily depends on the location, but the resistance has increased from the region where the change is likely to occur even if a thick probe is touched, and the voltage is more likely to be applied to the region where the resistance is still low. It can be expected that the resistance change will continue until the overall resistance increases. Conversely, when lowering the resistance of a high-resistance film, if a part of the resistance is lowered, current flows intensively, making it difficult to apply voltage to other contact surfaces. It is necessary to use a thin probe repeatedly. However, since the change in resistance is a reversible change, even if the metal oxide film before writing is a high resistance film, the resistance other than the circuit pattern may be increased after the resistance is once reduced.

  When applying a voltage, a DC voltage or a pulse voltage is applied. The applied bias condition is, for example, 9 V for nickel oxide having a thickness of 50 nm. If the thickness of the metal oxide is reduced, the metal resistance can be changed at a lower voltage. The scanning speed of the electrode 40 is 10 μm / s. When writing is completed, a circuit pattern is formed (FIG. 3 (f)).

  In the next step Sa6, the adhesive layer 26 is formed by applying an adhesive to the entire surface of the metal oxide film 23 on which the circuit pattern is formed, and the second base 27 is attached on the adhesive layer 26 (FIG. 3 (g)).

  In the next step Sa7, the first substrate 21 is separated from the light adhesion layer 25 formed in step Sa2 (second substrate 27 / adhesive layer 26 / metal oxide film 23 / conductive film 22). (FIG. 3 (h)). Through this step, the metal oxide film 23 fixed to the first substrate 21 is transferred to the second substrate 27. The material of the second base 27 can be the same as that of the first base 21. However, in the case of using a transparent electrode body for use in a touch panel or the like, the base body 27 needs to be transparent.

  In the next step Sa8, the conductive film 22 is removed (FIG. 3 (i)). The conductive film 22 is necessary to apply a voltage when forming a circuit pattern on the metal oxide film 23, but to be used as an electrode body, it must be removed after the circuit pattern is formed. This is because the wiring (low resistance region) of the circuit pattern is short-circuited by the conductive film 22.

  The method for removing the conductive film 22 may be selected as appropriate depending on the type and film thickness of the conductive film. For example, when the conductive film 22 is a metal film, a method of removing by dry etching with Ar plasma can be used. Wet etching is also possible as long as etching selectivity with the metal oxide film 23 and the second base 27 can be secured. When the conductive film 22 is an organic material such as an organic conductive polymer, it can be cleaned and peeled off with an organic solvent. When the conductive film 22 is carbon, it can be removed by heating in an oxygen atmosphere.

  The electrode body 10 having a circuit pattern as shown in FIG. 1 is obtained by sequentially performing the above steps Sa1 to Sa8 (step Sa9).

  In addition, when step Sa2 (formation process of the light adhesion layer 25) and step Sa3 (formation process of the electrically conductive film 22) are interchanged, the position of the light adhesion layer 25 is (second substrate 27 / adhesion layer 26 / metal oxide). Since it is located at the boundary between the material film 23) and (conductive film 22 / first substrate 21), the two are separated in this region. In this way, step Sa8 (the removal process of the conductive film 22) can be omitted. In this case, the light adhesion layer may be configured to have conductivity, and the circuit pattern may be formed by applying a voltage between the light adhesion layer 25 and the electrode 40.

(Third embodiment) -Structure of electrode body2-
FIG. 5 is a diagram schematically showing the structure of the electrode body as the third embodiment. FIG. 5A shows a cross-sectional view, and FIG. 5B shows a perspective view.

  The electrode body 20 shown in FIG. 5 shows a state in which a metal oxide film 23 is formed on the surface of a base 21 via an insulating film 22A that is an insulator.

  Similar to the first embodiment, the metal oxide film 23 includes a line composed of a region having a relatively high electrical resistance (high resistance region 23a) and a region having a relatively low electrical resistance (low resistance region 23b). And space is formed. The high resistance region 23a and the low resistance region 23b are electrically different in resistance value, but both have the same composition and optical characteristics (reflectance, transmittance, refractive index, etc.) are not changed at all.

  Metal oxide thin films generally have the property of changing electrical resistance when a voltage is applied. Specifically, materials having such properties include nickel oxide, titanium oxide, tantalum oxide, hafnium oxide, zirconium oxide, yttrium oxide, cerium oxide, magnesium oxide, zinc oxide, Indium oxide, tin oxide, tungsten oxide, niobium oxide, chromium oxide, manganese oxide, aluminum oxide, vanadium oxide, cobalt oxide, or copper oxide (copper oxide (I) or copper oxide ( II)), and a metal oxide film containing as a main component any of them. However, it is not necessarily limited to the stoichiometric composition, and some impurities may be contained.

  The substrate 21 is, for example, an insulating film and plays a role of fixing the electrode body 20. For example, when the electrode body 20 is used as a transparent electrode of a touch panel, the base body 21 needs to be transparent. On the other hand, when it is used simply as an electrode body having a fine circuit pattern, it is not necessarily transparent. The substrate 21 may be made of any material such as a glass substrate, an oxide substrate, a plastic substrate, and a plastic film as long as the laminated film of the insulating film 22A and the electrode body 20 can be fixed.

  The electrode body 20 shown in FIG. 5 is in a state where the wiring is embedded in the insulating film and has a flat surface, so that the optical characteristics are almost uniform.

(Fourth Embodiment) -Method 2 for Producing Electrode Body2-
Next, a manufacturing method of the electrode body shown in the third embodiment will be described with reference to FIGS.

  FIG. 8 is a diagram showing a manufacturing procedure of the electrode body configured as shown in FIG. The manufacturing procedure is roughly divided into steps Sb1 to Sb6. 6A to 6D are process cross-sectional views corresponding to steps Sb1 to Sb4 in FIG. 4, and FIGS. 7E to 7F correspond to steps Sa5 to Sa6 in FIG. It is process sectional drawing corresponding.

In the first step Sb1, a base 21 for supporting the electrode body is prepared (FIG. 6A).
The substrate 21 is preferably made of a transparent member such as a glass substrate, an oxide substrate, a plastic substrate, or a plastic film. Alternatively, the substrate may be polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethersulfone (PES), polyetheretherketone (PEEK), polycarbonate (PC), polypropylene (PP), polyamide (PA), It may be a flexible resin film such as polyacrylic (PAC), epoxy resin, phenol resin, aliphatic cyclic polyolefin, norbornene-based thermoplastic transparent resin, or a film made of a laminate of two or more of these.

  The base 21 serves as a support member for forming an electrode body having a circuit pattern. Therefore, it is necessary to select an appropriate member for the base body 21 according to the intended use of the electrode body. For example, a transparent member is selected for the substrate 21 when used as a transparent electrode used for a touch panel.

  In the next step Sb2, a conductive film 22 is formed on the surface of the base 21 (FIG. 6B). The conductive film 22 is used to cause the metal oxide film 23 formed in the next step (step Sb3) to function as an electrode for forming a circuit pattern. It is also necessary to lose.

  As the conductive film 22 satisfying such requirements, an organic conductive polymer is preferable. This is because the organic conductive polymer film is electrically conductive in the normal state after film formation, but becomes highly resistive and becomes an insulating film by irradiation with ultraviolet rays. As the organic conductive polymer, a polythiophene conductive polymer (for example, Denatron (registered trademark) manufactured by Nagase ChemteX Corporation), a polyaniline conductive polymer, and the like are particularly preferable. The organic conductive polymer film can be formed by a known coating method such as a bar coating method, a gravure coating method, a dip coating method, or a spin coating method.

  However, if it is possible to selectively increase the resistance of only the conductive film (that is, the portion excluding the low-resistance region serving as the circuit pattern formed on the metal oxide film 23) by a method other than ultraviolet irradiation, the conductive film The material of the film 22 is not limited to the organic conductive polymer.

  In the next step Sb3, a metal oxide film 23 having a thickness of, for example, about 50 nm is formed on the surface of the conductive film 22 (FIG. 6C). The metal oxide film 23 is made of nickel oxide, titanium oxide, tantalum oxide, hafnium oxide, zirconium oxide, yttrium oxide, cerium oxide, magnesium oxide, zinc oxide, indium oxide, tin oxide. , Tungsten oxide, niobium oxide, chromium oxide, manganese oxide, aluminum oxide, vanadium oxide, cobalt oxide, or copper oxide (copper oxide (I) or copper oxide (II)) What has either one as a main component is preferable.

  As a condition when using the sputtering method, for example, when nickel oxide is formed, nickel oxidation is performed by sputtering with Ni as a target metal at a pressure of 0.1 Pa, a substrate temperature at room temperature in a mixed gas of oxygen and argon. Things can be formed.

  In the next step Sb4, the electrode 40 is brought into contact with the surface of the metal oxide film 23 or brought close to a predetermined distance (FIG. 6D). The electrode 40 is connected to the power supply device 50, is configured to be able to apply a DC voltage between the conductive film 22 and the electrode 40, and is configured to be able to scan the electrode 40 with respect to the metal oxide film 23. Yes. As a device suitable for realizing this, specifically, a conductive atomic force microscope (C-AFM) capable of simultaneously measuring current and atomic force can be used. Instead of this, a scanning tunneling microscope (STM) or the like that measures tunneling current may be used. All of these use conductive cantilevers as electrodes, and are known as measuring devices that can obtain current images simultaneously with the uneven shape of the measurement object. By using this device, a metal oxide film can be obtained. It is possible to form a very fine circuit pattern.

  Note that the shape of the electrode 40 may be appropriately changed according to the circuit pattern to be created. For example, an electrode having a small tip diameter is used for a thin pattern, and a thick electrode is used for a thick pattern. In the case of forming a plurality of lines, needle-like electrodes may be arranged in a comb-like shape to increase manufacturing efficiency.

  When applying a voltage, a DC voltage is applied. The applied bias condition is, for example, 9 V for nickel oxide having a thickness of 50 nm. If the thickness of the metal oxide is reduced, the metal resistance can be changed at a lower voltage. Further, the scanning speed of the electrode 40 is, for example, 10 μm / s. When writing is completed, a circuit pattern is formed (FIG. 7E).

  In the next step Sb5, the entire surface is irradiated with ultraviolet rays from the back surface of the metal oxide film 23 on which the circuit pattern is formed, that is, from the substrate 21 side. As a result, the conductive film 22 loses its conductivity and becomes the insulating film 22A (FIG. 7F).

  The electrode body 10 having a circuit pattern as shown in FIG. 1 is obtained by sequentially performing the above steps Sb1 to Sb5 (step Sb6).

  Next, a touch panel to which the electrode body described in the first embodiment is applied will be described.

-Matrix resistive film method-
9A and 9B are configuration diagrams of a matrix resistance type touch panel, in which FIG. 9A is a plan view and FIG. 9B is a cross-sectional view taken along line X1-X1 in FIG. The basic configuration of the touch panel 200 is that two electrode bodies 10 each having a line-and-space circuit pattern configured in a sheet shape as shown in FIG. The spacers 30 are attached so as to face each other while ensuring the gap G so that they do not contact each other.

  The manufacturing method of the electrode body 10 can use each step described in the second embodiment. In this case, polyethylene terephthalate (PET) is used as the first base 21, wax is used as the light adhesion layer 25, aluminum is used as the conductive film 22, nickel oxide (NiO) is used as the metal oxide film 23, and film thickness is used as the second base 27, for example. Transparent members such as 125 μm polyethylene naphthalate (PEN) can be used.

  When the finger or pen is not touching the screen, the circuit pattern of the upper electrode body is not in contact with the circuit pattern of the lower electrode body due to the gap G, whereas when the finger or pen is touching the screen, At the position touched by the pen, the circuit pattern of the upper electrode body and the lower electrode body come into contact with each other, and the position touched by the finger or the pen can be specified by recognizing the conductive portion.

  Since the electrode body 10 used for this touch panel can have a very fine circuit pattern, there is an advantage that the resolution can be increased. Furthermore, there is an advantage that the optical characteristics are almost uniform because the surface of the circuit pattern is flat without any step.

-Projected capacitive method-
10A and 10B are configuration diagrams of a projected capacitive touch panel, where FIG. 10A is a plan view and FIG. 10B is a cross-sectional view taken along line X2-X2 in FIG. The basic configuration of the touch panel 201 is that two electrode bodies 10 each having a line-and-space circuit pattern configured in a sheet shape as shown in FIG. Are attached to face each other with an insulating substrate 31 interposed so as not to contact each other.

  As a manufacturing method of the electrode body 10, a method similar to the matrix resistive film method of this embodiment can be used.

  Normally, if the finger or pen is not touching the screen, the circuit pattern of the upper electrode body and the circuit pattern of the lower electrode body are held at a certain distance by the insulating substrate 31, so that the capacitance becomes constant. The capacitance changes at the part touched by the pen. Therefore, the position where the finger or the pen touched can be specified by recognizing the part where the capacitance has changed.

  Since the electrode body 10 used for this touch panel can have a very fine circuit pattern, there is an advantage that the resolution can be increased. Furthermore, there is an advantage that the optical characteristics are almost uniform because the surface of the circuit pattern is flat without any step.

  Next, a touch panel to which the electrode body described in the third embodiment is applied will be described.

-Matrix resistive film method-
11A and 11B are configuration diagrams of a matrix resistance touch panel, where FIG. 11A is a plan view and FIG. 11B is a cross-sectional view taken along line Y1-Y1 in FIG. The basic configuration of the touch panel 202 is that two electrode bodies 20 each having a line-and-space circuit pattern configured in a sheet shape as shown in FIG. The spacers 30 are attached so as to face each other while ensuring the gap G so that they do not contact each other.

  The manufacturing method of the electrode body 20 can use each step described in the fourth embodiment. In this case, polyethylene naphthalate (PEN) is used as the substrate 21, and the conductive film 22 formed on the substrate 21 is an organic conductive polymer as a member that increases resistance by ultraviolet irradiation, specifically, manufactured by Nagase ChemteX Corporation. Denatron (registered trademark) or the like can be used. After the ultraviolet irradiation, the conductive film 22 becomes the insulating film 22A. Nickel oxide (NiO) can be used as the metal oxide film 23.

  When the finger or pen is not touching the screen, the circuit pattern of the upper electrode body is not in contact with the circuit pattern of the lower electrode body due to the gap G, whereas when the finger or pen is touching the screen, At the position touched by the pen, the circuit pattern of the upper electrode body and the lower electrode body come into contact with each other, and the position touched by the finger or the pen can be specified by recognizing the conductive portion.

  Since the electrode body 20 used for this touch panel can have a very fine circuit pattern, there is an advantage that the resolution can be increased. Furthermore, there is an advantage that the optical characteristics are almost uniform because the surface of the circuit pattern is flat without any step.

-Projected capacitive method-
12A and 12B are configuration diagrams of a projected capacitive touch panel, where FIG. 12A is a plan view and FIG. 12B is a cross-sectional view taken along line Y2-Y2 of FIG. The basic configuration of the touch panel 203 is that two electrode bodies 20 having a line-and-space circuit pattern configured in a sheet shape as shown in FIG. Are attached to face each other with an insulating substrate 31 interposed so as not to contact each other.

  As a manufacturing method of the electrode body 20, a method similar to the matrix resistive film method of the present embodiment can be used.

Normally, if the finger or pen is not touching the screen, the circuit pattern of the upper electrode body and the circuit pattern of the lower electrode body are held at a certain distance by the insulating substrate 31, so that the capacitance becomes constant. The capacitance changes at the part touched by the pen. Therefore, the position where the finger or the pen touched can be specified by recognizing the part where the capacitance has changed.

  Since the electrode body 20 used for this touch panel can have a very fine circuit pattern, there is an advantage that the resolution can be increased. Furthermore, there is an advantage that the optical characteristics are almost uniform because the surface of the circuit pattern is flat without any step.

  According to the present invention, it is possible to form an ultrafine circuit pattern, which has been difficult in the past by a relatively simple method, and in various technical fields such as a fine circuit and a touch panel electrode, and a manufacturing method thereof. As such, the industrial applicability is extremely large.

10, 20 Electrode body 21 (first) substrate 22 conductive film 22A insulating film 23 metal oxide film 23a high resistance region 23b low resistance region 25 light adhesion layer 26 adhesion layer 27 (second) substrate 40 electrode 50 power supply device 200-203 touch panel

Claims (18)

An electrode is brought into contact with or brought close to a predetermined distance to the metal oxide film on the substrate having a laminated film on which the conductive film and the metal oxide film are formed in this order. In this state, the electrode and the conductive film and a step of forming a circuit pattern by locally changing the relative position changing the specific resistance of the metal oxide film between the front Symbol electrode and the metal oxide film together when a voltage is applied between the A method for manufacturing an electrode body, wherein the voltage generates an electric field necessary and sufficient to move oxygen contained in the metal oxide film as oxygen ions. Method.
The step of forming the circuit pattern includes a step of reducing the specific resistance of the metal oxide film over the entire region where the circuit pattern is formed, and then a step of increasing the resistance of a portion other than the circuit pattern. The manufacturing method of the electrode body of description. In the step of forming the circuit pattern, the step of locally changing the specific resistance of the metal oxide film includes:
A relatively low resistance step by applying a positive voltage comprising a positive DC voltage or a positive pulse voltage to the metal oxide film;
2. The method according to claim 1, comprising either or both of a step of relatively increasing the resistance by applying a negative voltage comprising a negative DC voltage or a negative pulse voltage to the metal oxide film. Or the manufacturing method of the electrode body of 2. In the step of applying the positive or negative voltage, by controlling the applied voltage or the amount of current passing through the metal oxide film based on the applied voltage, regions having different specific resistances in the circuit pattern The method of manufacturing an electrode body according to claim 3, wherein: 5. The method of manufacturing an electrode body according to claim 4, wherein the means for controlling the voltage to be applied connects a resistor in series with the electrode. 5. The method of manufacturing an electrode body according to claim 4, wherein the means for controlling the amount of current passing through the metal oxide film based on the applied voltage uses a current limiting circuit using a semiconductor or other active element. . The step of forming the circuit pattern includes forming a relatively low resistance metal oxide film, and then applying a negative voltage composed of a negative DC voltage or a negative pulse voltage to a relatively high resistance region. 2. The method of manufacturing an electrode body according to claim 1, wherein the electrode is locally formed in the metal oxide film. 8. The method of manufacturing an electrode body according to claim 7, wherein the metal oxide film is a metal oxide film doped with impurities. The metal oxide film is nickel oxide, titanium oxide, tantalum oxide, hafnium oxide, zirconium oxide, yttrium oxide, cerium oxide, magnesium oxide, zinc oxide, indium oxide, tin oxide. , Tungsten oxide, niobium oxide, chromium oxide, manganese oxide, aluminum oxide, vanadium oxide, cobalt oxide, or copper oxide (copper oxide (I) or copper oxide (II)) The manufacturing method of the electrode body of Claim 1 which has any one as a main component. The method of manufacturing an electrode body according to claim 1, wherein the electrode is a conductive probe used in a conductive atomic force microscope (C-AFM). The method of manufacturing an electrode body according to claim 2, wherein the electrode is configured in a comb-teeth shape. The method for producing an electrode body according to claim 1, wherein a light adhesion layer is formed between the base and the laminated film or between the conductive film and the metal oxide film in the laminated film. The base is composed of a transparent member that transmits ultraviolet rays, and the conductive film is composed of a member that increases resistance by ultraviolet irradiation, and after the step of forming the circuit pattern, The method for producing an electrode body according to claim 1, further comprising a step of irradiating with ultraviolet rays. The method for producing an electrode body according to claim 13, wherein the member whose resistance is increased by ultraviolet irradiation is an organic conductive polymer. A metal oxide is laminated on a substrate via an adhesive layer, and the metal oxide film has a circuit pattern formed of a region having a relatively low specific resistance in a metal oxide film having a relatively high specific resistance. An electrode body characterized by comprising: An organic polymer film and a metal oxide film are laminated on a substrate, and the metal oxide film has a circuit pattern composed of a region having a relatively low specific resistance within a metal oxide film having a relatively high specific resistance. An electrode body, wherein the organic polymer film is formed of an insulator. The electrode body according to claim 16, wherein the sheet resistance value of the organic polymer film is at least 100 MΩ / □ or more. The transparent electrode body for touchscreens containing the electrode body of any one of Claim 15 thru | or 17.

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