WO2020235591A1 - Variable resistance device and method for producing same - Google Patents

Variable resistance device and method for producing same Download PDF

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WO2020235591A1
WO2020235591A1 PCT/JP2020/019937 JP2020019937W WO2020235591A1 WO 2020235591 A1 WO2020235591 A1 WO 2020235591A1 JP 2020019937 W JP2020019937 W JP 2020019937W WO 2020235591 A1 WO2020235591 A1 WO 2020235591A1
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variable resistance
electrode
organic film
resistance device
voltage
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PCT/JP2020/019937
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French (fr)
Japanese (ja)
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正規 河野
博義 大津
ジェジュン キム
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国立大学法人東京工業大学
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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K10/00—Organic devices specially adapted for rectifying, amplifying, oscillating or switching; Organic capacitors or resistors having potential barriers
    • H10K10/10—Organic capacitors or resistors having potential barriers
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
    • C07D401/14—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing three or more hetero rings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
    • H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body
    • H01L27/10—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including a plurality of individual components in a repetitive configuration
    • H01L27/105—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including a plurality of individual components in a repetitive configuration including field-effect components
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10B—ELECTRONIC MEMORY DEVICES
    • H10B99/00—Subject matter not provided for in other groups of this subclass
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N99/00—Subject matter not provided for in other groups of this subclass

Definitions

  • the present invention relates to a variable resistance device and a method for manufacturing the same.
  • a non-volatile variable resistance memory As a next-generation memory, a non-volatile variable resistance memory is known. As such a variable resistance memory, a device that utilizes the formation and erasure of a filament of a metal oxide is known.
  • variable resistance memory an organic ferroelectric memory using a ferroelectric organic substance is also known.
  • variable resistance type memory an organic memory having a floating gate structure is also known.
  • Patent Document 1 describes "a non-volatile storage device having a storage layer of a polyimide film in which chargeable fine particles are dispersed between a first conductive portion and a second conductive portion" as a variable resistance memory. Will be disclosed.
  • variable resistance type memory In such a variable resistance type memory, further improvement is desired from the viewpoint of high integration, durability, or atmospheric stability.
  • an object of the present invention is to provide a new variable resistance device in which the resistance state is variable.
  • one of the representative variable resistance devices of the present invention includes an organic film and a first electrode and a second electrode at least partially facing each other with both sides of the organic film interposed therebetween.
  • This organic film contains (1) ⁇ -type organic molecules having redox activity, (2) ⁇ -type organic molecules are in a state of ⁇ - ⁇ stacking in the stacking direction of the organic film, and (3) ⁇ -type organic molecules. Is an anisotropic orientation.
  • the present invention provides a resistance variable device including an organic film having a variable resistance state.
  • FIG. 1 is a schematic view showing the structure of the variable resistance device 10 of the first embodiment.
  • FIG. 2 is a diagram showing a general formula of a ⁇ -type organic molecule contained in the organic film 13.
  • FIG. 3 is a schematic diagram illustrating the redox activity of 1,3-diazaphenalenyl.
  • FIG. 4 is a diagram showing the molecular structure of 2,5,8-tri (4-pyridyl) 1,3-diazaphenalene, which is TPDAP.
  • FIG. 5 is a diagram showing an intermolecular network of TPDAP in the plane direction of the organic film 13.
  • FIG. 6 is a diagram showing a state of TPDAP in the stacking direction of the organic film 13.
  • FIG. 1 is a schematic view showing the structure of the variable resistance device 10 of the first embodiment.
  • FIG. 2 is a diagram showing a general formula of a ⁇ -type organic molecule contained in the organic film 13.
  • FIG. 3 is a schematic diagram illustrating the redox activity
  • FIG. 7 is a diagram illustrating a method of forming an organic film 13 using TPDAP as a film material.
  • FIG. 10 is a diagram showing a difference in electrical characteristics depending on the orientation state of the organic film 13.
  • FIG. 11 is a diagram illustrating the basic operation of the variable resistance device 10.
  • FIG. 12 is a diagram showing voltage-current characteristics depending on the film thickness of the organic film.
  • FIG. 13 is a diagram showing voltage-current characteristics depending on the cell size.
  • FIG. 14 is a diagram showing the insulation characteristics of the anisotropic organic film 13 (aniso-TPDAP) in the plane direction.
  • FIG. 15 is a diagram showing the change over time in the non-volatility of the anisotropic organic film 13 (aniso-TPDAP).
  • FIG. 16 is a diagram showing the change with time of non-volatility of the anisotropic organic film 13 (aniso-TPDAP) under high temperature.
  • FIG. 17 is a diagram showing the durability of rewriting of the anisotropic organic film 13 (aniso-TPDAP).
  • FIG. 18 is a diagram showing the atmospheric stability of the anisotropic organic film 13 (aniso-TPDAP).
  • FIG. 19 is a diagram showing an example of voltage distribution when the variable resistance device 10 is used as a memory integrated device.
  • FIG. 20 is a diagram illustrating the organic field effect transistor 300 of the second embodiment.
  • FIG. 1 is a schematic view showing the structure of the variable resistance device 10 of the first embodiment.
  • variable resistance device 10 includes a substrate 11, a first electrode 12, an organic film 13, and a plurality of second electrodes 14.
  • the substrate 11 is composed of, for example, a silicon substrate Si and an insulating layer SiO 2 formed by oxidizing the surface thereof.
  • the first electrode 12 is formed on the surface of the insulating layer SiO 2 using, for example, gold Au as an electrode material.
  • the two-dimensional direction in which the film spreads is referred to as the "plane direction", and the direction of the film thickness of the organic film 13 is referred to as the "stacking direction”.
  • the organic film 13 is formed on the surface of the first electrode 12 and has the following characteristics. (1) The organic film 13 contains a ⁇ -type organic molecule having a redox activity. (2) The ⁇ -type organic molecule is in a ⁇ - ⁇ stacking state in the stacking direction of the organic film 13. (3) The ⁇ -type organic molecule contained in the organic film 13 exhibits an anisotropic orientation.
  • the state of ⁇ - ⁇ stacking means a state in which the atoms constituting the molecule are self-aligned along the stacking direction due to the intermolecular interaction of ⁇ -type organic molecules by ⁇ - ⁇ stacking.
  • it means both a state in which at least two aromatic rings of aromatic organic molecules are arranged overlapping each other, or a state in which at least two aromatic rings are arranged slightly offset.
  • Anisotropic orientation means a state in which ⁇ -type organic molecules contained in the organic film 13 or their crystals are aligned.
  • the plurality of second electrodes 14 are patterned on the surface of the organic film 13 according to the arrangement pattern of predetermined variable resistance cells (memory cells) using, for example, gold Au as an electrode material.
  • variable resistance device 10 having such a configuration, a common voltage Vo is applied to the first electrode 12 individually by a circuit (not shown) and a wiring pattern (not shown) for data recording, data erasing, and data reading.
  • a controlled control voltage Vx is applied to each of the plurality of second electrodes 14.
  • ⁇ -type organic molecules are self-aligned in atomic units in the stacking direction of the organic film 13, and the current (carrier) A propagation path is formed. It is considered that resistance changes (high conduction state / low conduction state) occur in the stacking direction of the organic film 13 by introducing carriers or discharging carriers by redoxing in the propagation path.
  • FIG. 2 is a diagram showing a general formula of a ⁇ -type organic molecule contained in the organic film 13. At the center of the general formula of this ⁇ -type organic molecule is 1,3-diazaphenalenyl, which is composed of three rings and has a ⁇ -electron conjugated system.
  • FIG. 3 is a schematic diagram illustrating the redox activity of 1,3-diazaphenalenyl. As shown in the figure, the 1,3-diazaphenalenyl-based ⁇ -type organic molecule has redox activity.
  • this 1,3-diazaphenalenyl has functional groups that serve as acceptors (N) and proton donors (NH) at positions 1 and 3.
  • the ⁇ -type organic molecule has proton transfer ability and electron donor property in addition to redox activity.
  • 1,3-diazaphenalenyl is characterized by forming hydrogen bonds between molecules, which makes it possible to construct an integrated intermolecular network.
  • Y1, Y2, Y3 are placed in the 2, 5 and 8 positions of this 1,3-diazaphenalenyl, respectively.
  • Each of Y1 to Y3 is a saturated or unsaturated hydrocarbon group having 1 to 60 carbon atoms, and these hydrocarbon groups may have one or more substituents. Further, one or more carbon atoms among these hydrocarbon groups are an oxygen atom, a sulfur atom, a silicon atom, and -NR- (where R is a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. , Or an aryl group having 6 to 30 carbon atoms), ⁇ NR2, an aromatic group, a hydroxyl group, or a carboxylic acid. In addition, these Y1 to Y3 may be the same or different.
  • TPDAP ⁇ Explanation of TPDAP >> Subsequently, TPDAP will be described as a representative example of the ⁇ -type organic molecule.
  • FIG. 4 is a diagram showing the molecular structure of 2,5,8-tri (4-pyridyl) 1,3-diazaphenalene called TPDAP.
  • 4-pyridyl is arranged as Y1 to Y3 at the 2, 5 and 8 positions of 1,3-diazaphenalenyl, respectively.
  • FIG. 5 is a diagram showing an intermolecular network of TPDAP in the plane direction of the organic film 13.
  • FIG. 6 is a diagram showing a state of TPDAP in the stacking direction of the organic film 13.
  • the atoms constituting the molecule are self-aligned in the stacking direction by the action of ⁇ - ⁇ stacking, so that they are densely stacked.
  • a current (carrier) propagation path can be formed in the stacking direction.
  • FIG. 7 is a diagram illustrating a method of forming an organic film 13 using TPDAP as a film material.
  • the vapor deposition apparatus 201 includes a high vacuum pump 202, a filament boat 204 on which a sample 203 of TPDAP is arranged, and a holder 205 on which a substrate 11 is arranged.
  • the high vacuum pump 202 transitions the inside of the vapor deposition apparatus 201 to a vacuum level of, for example, about 1E-6 Torr.
  • the filament boat 204 heats the sample 203 of TPDAP to, for example, about 230 ° C. and evaporates it.
  • the vaporized TPDAP crystals are deposited on the surface of the substrate 11 to form an organic film 13.
  • the film thickness of the organic film 13 is set by adjusting the transpiration density and the vapor deposition time.
  • the orientation of the crystals and molecules of the organic film 13 can be controlled.
  • GIWAXS micro-angle incident wide-angle X-ray scattering
  • the orientation of the organic film 13 is , It is recognized that it shows isotropicity that is not aligned in the stacking direction.
  • the orientation of the organic film 13 is the stacking direction. It is recognized that it shows anisotropy aligned with. Inside the organic film 13 exhibiting this anisotropic orientation, the action of ⁇ - ⁇ stacking in the stacking direction is synergistic, and the atoms constituting the TPDAP molecule are self-aligned in the stacking direction.
  • the anisotropic orientation can be controlled by the formation temperature of the organic film 13.
  • the upper part [A] of FIG. 10 shows the results of measuring the voltage-current characteristics in the stacking direction of the organic film 13 showing an isotropic orientation. As shown in the figure, in the isotropic organic film 13, a discontinuous critical change does not occur in the voltage-current characteristics in the stacking direction.
  • the upper part [B] of FIG. 10 shows the results of measuring the voltage-current characteristics in the stacking direction of the organic film 13 showing an anisotropic orientation.
  • the horizontal axis of the figure shows the voltage value applied in the stacking direction of the organic film 13, and the vertical axis of the figure shows the magnitude (absolute value) of the current flowing in the stacking direction of the organic film 13.
  • a discontinuous critical change occurs in the voltage-current characteristics in the stacking direction only in the anisotropic organic film 13.
  • variable resistance device 10 Since the variable resistance device 10 applies a voltage to the anisotropic organic film 13 in the stacking direction by the first electrode 12 and the second electrode 14, the variable resistance device 10 operates according to the voltage-current characteristics shown in FIG. 10 [B].
  • FIG. 11 is a diagram illustrating the basic operation of the variable resistance device 10.
  • the horizontal axis indicates the voltage difference (Vx-Vo) between the second electrode 14 and the first electrode 12.
  • the vertical axis indicates the magnitude (absolute value) of the current flowing between the second electrode 14 and the first electrode 12 via the stacking direction of the organic film 13.
  • This low conduction state has a non-volatile property because it can be reproduced regardless of whether the first electrode 12 and the second electrode 14 are electrically short-circuited or opened.
  • This high conduction state also has a non-volatile property because it can be reproduced regardless of whether the first electrode 12 and the second electrode 14 are electrically short-circuited or opened.
  • the resistivity ratio between the low-conductivity state and the high-conductivity state shows a large on-off resistance ratio of about "10 to the 6th power".
  • variable resistance device 10 repeats the state transition through the cycle orbits of the low conduction state and the high conduction state along the direction of the arrow shown in FIG. It is considered that this is because the molecular arrangement of the organic film having redox activity causes the memory effect.
  • FIG. 12 is a diagram showing voltage-current characteristics due to the film thickness of the organic film when a voltage is applied between the second electrode 14 and the first electrode 12 as in the case of FIG.
  • the TPDAP film thickness is changed to 65 nm, 100 nm, and 130 nm
  • the turn-on voltage is a little over 2 V
  • the turn-off voltage is about -1 V
  • the film thickness is 100 nm.
  • the turn-on voltage is a little over 3V and the turn-off voltage is about ⁇ 1.5V, and when the film thickness is 130 nm, the turn-on voltage is a little over 3.5V and the turn-off voltage is about -2V. From this, it can be seen that the variable resistance device of the present embodiment has a film thickness dependence on the voltage-current characteristics.
  • the drive voltage of the variable resistance device 10 can be reduced. Further, by thickening the organic film 13, it becomes possible to expand the voltage range in which the variable resistance device 10 can be used as a resistor, a switch, or a recording medium. Since the turn-off voltage also depends on the film thickness, the resistance variable mechanism of the variable resistance device of the present embodiment is a mechanism in which metal ions move in the organic film to form thin filaments and connect the electrodes ( It is presumed that this is not the so-called "filament formation mechanism").
  • FIG. 13 is a diagram showing voltage-current characteristics according to cell size when a voltage is applied between the second electrode 14 and the first electrode 12 as in the case of FIG.
  • the turn-on voltage is about 3.5 V and the turn-off voltage is about -1.5 V when the cell size is 50 ⁇ m, and when the cell size is 100 ⁇ m.
  • the turn-on voltage is a little over 3.7V and the turn-off voltage is about -1.7V.
  • the cell size in the present embodiment indicates the diameter of the second electrode 14 shown in FIG. From this, it can be seen that the variable resistance device of the present embodiment has a cell size dependence on the voltage-current characteristic.
  • FIG. 14 is a diagram showing the results of measuring the voltage-current characteristics of the anisotropic organic film 13 (aniso-TPDAP) in the plane direction.
  • the anisotropic organic film 13 causes only a very weak leakage current to flow in the plane direction, and exhibits excellent insulation characteristics.
  • variable resistance device 10 can be configured with a simple basic structure as shown in FIG.
  • variable resistance cell (memory cell) can be easily miniaturized and highly integrated.
  • the area of the second electrode 14 of the variable resistance cell (memory cell) is on the order of the molecular size. It becomes possible to make it finer and highly integrated.
  • FIG. 15 is a diagram showing the results of measuring the non-volatile stability over time of the anisotropic organic film 13 (aniso-TPDAP).
  • variable resistance device 10 As shown in the figure, no noticeable change in the amount of current was observed in the measured time range in both the low conduction state and the high conduction state, and the non-volatility of the variable resistance device 10 was well maintained. There is.
  • FIG. 16 is a diagram showing the durability of the anisotropic organic film 13 (aniso-TPDAP) at high temperatures. Even at a high temperature of 120 degrees Celsius where the computer operates, no noticeable change in the amount of current was observed in the measured time range in both the low conduction state and the high conduction state, and the variable resistance device 10 was used. Non-volatileity is well maintained.
  • FIG. 17 is a diagram showing the results of measuring the rewriting durability of the anisotropic organic film 13 (aniso-TPDAP). As shown in the figure, in both the low conduction state and the high conduction state, no noticeable change was observed in the amount of current within the measured number of rewrites, and even if the rewrites (turn-on and turn-off) were repeated, The durability of the variable resistance device 10 is well maintained.
  • FIG. 18 is a diagram showing the results of measuring the atmospheric stability under water vapor by repeatedly exposing the organic film 13 (aniso-TPDAP) to nitrogen gas containing water vapor. As shown in the figure, there is no noticeable change in the amount of current flowing through the organic film 13 regardless of the presence or absence of nitrogen gas containing water vapor. Therefore, the variable resistance device 10 exhibits high atmospheric stability under water vapor.
  • each region forming the variable resistance cell (memory cell) in the organic film 13 is substantially covered with the second electrode 14. Even if molecules in the air enter the inside of the organic film 13 (aniso-TPDAP) through the gaps in the arrangement of the second electrodes 14, they are variable due to the insulation characteristics of the organic film 13 (aniso-TPDAP) itself in the plane direction. It is also considered that this is because it does not easily affect the electrical characteristics of the resistance cell (memory cell).
  • the organic membrane 13 (aniso-TPDAP) is less likely to be contaminated by molecules in the air during the manufacturing process of the device, so that the air cleaning level at the time of manufacturing the variable resistance device 10 can be lowered. There are practical advantages such as high yield.
  • the control voltage Vx 2.25 [V] is applied to the second electrode 14.
  • variable resistance device 10 As a switching device
  • the variable resistance device 10 shown in FIG. 1 can also be used as a switching device.
  • the high conduction state of the organic film 13 is utilized as the switch ON state, and the organic film 13 is organic.
  • the low conduction state of the film 13 is used as the switch OFF state.
  • the upper part [A] of FIG. 20 is a schematic view showing the configuration of the organic field effect transistor 300.
  • the organic field effect transistor 300 includes a gate G made of an N-type Si layer, an insulating layer 302 made of SiO 2 , a graphene 303 capable of forming a channel path as a first electrode, and aniso-TPDAP.
  • the film 304 is provided with a drain D and a source S as a second electrode having a gold Au pattern on the upper surface of the organic film 304.
  • the gate G and the insulating layer 302 function as a gate mechanism for controlling the channel path of the graphene 303.
  • the voltage divided in the stacking direction of the organic film 304 rises and exceeds the turn-on voltage of the organic film 304.
  • the stacking direction of the organic film 304 in contact with either the drain D or the source S turns on.
  • the voltage Vds is intensively applied in the stacking direction of the organic film 304 in contact with the drain D or the other of the source S, and exceeds the turn-on voltage of the organic film 304.
  • the stacking direction of the organic film 304 in contact with the drain D or the other of the source S is also turned on.
  • the stacking directions of the organic films 304 in contact with both the drain D and the source S are both turned on.
  • the channel of graphene 303 can be controlled by the applied voltage of the gate G, and the drain current flowing through the drain D can be controlled.
  • the middle stage [B] of FIG. 20 is a diagram showing the characteristics of the gate voltage-drain current of the organic field effect transistor 300.
  • organic field effect transistors that use graphene in the channel path have a low on-off current ratio.
  • the on-off current ratio can be increased to about (10 to the 6th power) times.
  • the organic film 13 is formed by a vapor deposition method.
  • the present invention is not limited to this.
  • the ⁇ -type organic molecule may be dissolved in a solvent and dropped or applied to the substrate 11 as a solution, and the film thickness of the organic film 13 may be controlled by the solution concentration or centrifugal force.
  • the solvent refers to, for example, a general organic solvent, and is not limited as long as it dissolves ⁇ -type organic molecules.
  • the high conduction state or the low conduction state is stored as data by applying a read voltage between the first electrode 12 and the second electrode 14 within a range not exceeding the turn-on voltage and the turn-off voltage. Is read as.
  • the present invention is not limited to this.
  • the high conduction state or the low conduction state may be read out as stored data by passing a read current between the first electrode 12 and the second electrode 14 within a range not exceeding the turn-on voltage and the turn-off voltage.
  • variable resistance device is used as an integrated element by providing a plurality of second electrodes 14.
  • the present invention is not limited to this.
  • the variable resistance device may be a single element.
  • the organic film 304 is provided under the drain D and the source S.
  • the present invention is not limited to this.
  • the organic film 304 under one of the drain D and the source S may be omitted (see the lower part [C] of FIG. 20). Even in such a configuration, since the organic film 304 under the other of the drain D and the source S functions as a current barrier, it is possible to obtain an organic field effect transistor having a high on / off current ratio.

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Abstract

The purpose of the present invention is to provide a novel variable resistance device, the resistance state of which is variable.　Consequently, one of typical variable resistance devices according to the present invention is provided with: an organic film; and a first electrode and a second electrode, which at least partially face each other, with the both surfaces of the organic film being interposed therebetween. This organic film is characterized in that: (1) π-type organic molecules having redox activity are contained therein; (2) the π-type organic molecules show π-π stacking in the stacking direction of the organic film; and (3) the π-type organic molecules show orientation anisotropy. For example, one suitable example of these π-type organic molecules is 2, 5, 8-tri(4-pyridyl)1, 3-diazaphenalene showing orientation anisotropy (so-called "aniso-TPDAP").

Description

可変抵抗デバイスおよびその製造方法Variable resistor device and its manufacturing method
　本発明は、可変抵抗デバイスおよびその製造方法に関する。 The present invention relates to a variable resistance device and a method for manufacturing the same.
　次世代メモリとして、不揮発性の抵抗可変型メモリが知られている。
　このような抵抗可変型メモリとして、金属酸化物のフィラメントの形成および消去を利用するデバイスが知られる。 As a next-generation memory, a non-volatile variable resistance memory is known.
As such a variable resistance memory, a device that utilizes the formation and erasure of a filament of a metal oxide is known.
　また、抵抗可変型メモリとして、強誘電性の有機物を使用する有機強誘電性メモリも知られる。 Also, as a variable resistance memory, an organic ferroelectric memory using a ferroelectric organic substance is also known.
　さらに、抵抗可変型メモリとして、フローティングゲート構造の有機メモリも知られる。 Further, as a variable resistance type memory, an organic memory having a floating gate structure is also known.
　また、特許文献１には、抵抗可変型メモリとして『第１導電部と第２導電部との間に、帯電可能な微小粒子を分散させたポリイミド膜の記憶層を有する不揮発性記憶装置』が開示される。 Further, Patent Document 1 describes "a non-volatile storage device having a storage layer of a polyimide film in which chargeable fine particles are dispersed between a first conductive portion and a second conductive portion" as a variable resistance memory. Will be disclosed.
特開２０１４－０２７１８５公報Japanese Unexamined Patent Publication No. 2014-027185
　このような抵抗可変型メモリでは、高集積化、耐久性、または大気安定性の観点において、更なる向上が望まれる。 In such a variable resistance type memory, further improvement is desired from the viewpoint of high integration, durability, or atmospheric stability.
　そこで、本発明は、抵抗状態が可変する新たな抵抗可変デバイスを提供することを目的とする。 Therefore, an object of the present invention is to provide a new variable resistance device in which the resistance state is variable.
　上記課題を解決するために、代表的な本発明の可変抵抗デバイスの一つは、有機膜と、有機膜の両面を挟んで少なくとも一部が対向する第１電極および第２電極とを備える。この有機膜は、（１）酸化還元活性を有するπ型有機分子を含み、（２）π型有機分子は有機膜の積層方向にπ－πスタッキングの状態であり、（３）π型有機分子は異方性の配向である、ことを特徴とする。 In order to solve the above problems, one of the representative variable resistance devices of the present invention includes an organic film and a first electrode and a second electrode at least partially facing each other with both sides of the organic film interposed therebetween. This organic film contains (1) π-type organic molecules having redox activity, (2) π-type organic molecules are in a state of π-π stacking in the stacking direction of the organic film, and (3) π-type organic molecules. Is an anisotropic orientation.
　本発明により、抵抗状態が可変する有機膜を備えた抵抗可変デバイスが提供される。
　それ以外の課題、構成及び効果は、以下の実施形態の説明により明らかにされる。 INDUSTRIAL APPLICABILITY The present invention provides a resistance variable device including an organic film having a variable resistance state.
Other issues, configurations and effects will be clarified by the description of the following embodiments.
図１は、実施例１の可変抵抗デバイス１０の構造を示す模式図である。FIG. 1 is a schematic view showing the structure of the variable resistance device 10 of the first embodiment. 図２は、有機膜１３に含まれるπ型有機分子の一般式を示す図である。FIG. 2 is a diagram showing a general formula of a π-type organic molecule contained in the organic film 13. 図３は、1,3-diazaphenalenylの酸化還元活性を説明する模式図である。FIG. 3 is a schematic diagram illustrating the redox activity of 1,3-diazaphenalenyl. 図４は、ＴＰＤＡＰである2,5,8-tri(4-pyridyl)1,3-diazaphenaleneの分子構造を示す図である。FIG. 4 is a diagram showing the molecular structure of 2,5,8-tri (4-pyridyl) 1,3-diazaphenalene, which is TPDAP. 図５は、有機膜１３の面方向におけるＴＰＤＡＰの分子間のネットワークを示す図である。FIG. 5 is a diagram showing an intermolecular network of TPDAP in the plane direction of the organic film 13. 図６は、有機膜１３の積層方向におけるＴＰＤＡＰの状態を示す図である。FIG. 6 is a diagram showing a state of TPDAP in the stacking direction of the organic film 13. 図７は、ＴＰＤＡＰを膜材料として有機膜１３を生成する方法を説明する図である。FIG. 7 is a diagram illustrating a method of forming an organic film 13 using TPDAP as a film material. 図８は、形成温度Ｔｓ＝８０°Ｃで形成された有機膜１３の特性を示す図である。FIG. 8 is a diagram showing the characteristics of the organic film 13 formed at the formation temperature Ts = 80 ° C. 図９は、形成温度Ｔｓ＝２５°Ｃで形成された有機膜１３の特性を示す図である。FIG. 9 is a diagram showing the characteristics of the organic film 13 formed at the formation temperature Ts = 25 ° C. 図１０は、有機膜１３の配向状態による電気的特性の違いを示す図である。FIG. 10 is a diagram showing a difference in electrical characteristics depending on the orientation state of the organic film 13. 図１１は、可変抵抗デバイス１０の基本動作を説明する図である。FIG. 11 is a diagram illustrating the basic operation of the variable resistance device 10. 図１２は、有機膜の膜厚による電圧－電流特性を示す図である。FIG. 12 is a diagram showing voltage-current characteristics depending on the film thickness of the organic film. 図１３は、セルサイズによる電圧－電流特性を示す図である。FIG. 13 is a diagram showing voltage-current characteristics depending on the cell size. 図１４は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）の面方向の絶縁特性を示す図である。FIG. 14 is a diagram showing the insulation characteristics of the anisotropic organic film 13 (aniso-TPDAP) in the plane direction. 図１５は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）の不揮発性の経時変化を示す図である。FIG. 15 is a diagram showing the change over time in the non-volatility of the anisotropic organic film 13 (aniso-TPDAP). 図１６は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）の高温下における不揮発性の経時変化を示す図である。FIG. 16 is a diagram showing the change with time of non-volatility of the anisotropic organic film 13 (aniso-TPDAP) under high temperature. 図１７は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）の書き換えの耐久性を示す図である。FIG. 17 is a diagram showing the durability of rewriting of the anisotropic organic film 13 (aniso-TPDAP). 図１８は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）の大気安定性を示す図である。FIG. 18 is a diagram showing the atmospheric stability of the anisotropic organic film 13 (aniso-TPDAP). 図１９は、可変抵抗デバイス１０をメモリ集積デバイスとして使用する際の電圧配分の一例を示す図である。FIG. 19 is a diagram showing an example of voltage distribution when the variable resistance device 10 is used as a memory integrated device. 図２０は、実施例２の有機電界効果トランジスタ３００を説明する図である。FIG. 20 is a diagram illustrating the organic field effect transistor 300 of the second embodiment.
　以下、図面を用いて実施例を説明する。 Hereinafter, examples will be described with reference to the drawings.
　《可変抵抗デバイス１０の構造》
　図１は、実施例１の可変抵抗デバイス１０の構造を示す模式図である。 << Structure of variable resistance device 10 >>
FIG. 1 is a schematic view showing the structure of the variable resistance device 10 of the first embodiment.
　同図において、可変抵抗デバイス１０は、基板１１、第１電極１２、有機膜１３、および複数の第２電極１４を備える。 In the figure, the variable resistance device 10 includes a substrate 11, a first electrode 12, an organic film 13, and a plurality of second electrodes 14.
　基板１１は、例えば、シリコン基板Ｓｉと、その表面を酸化して形成された絶縁層ＳｉＯ２とから構成される。 The substrate 11 is composed of, for example, a silicon substrate Si and an insulating layer SiO 2 formed by oxidizing the surface thereof.
　第１電極１２は、例えば金Ａｕを電極材料として、絶縁層ＳｉＯ２の面上に形成される。 The first electrode 12 is formed on the surface of the insulating layer SiO 2 using, for example, gold Au as an electrode material.
　なお、以下では、有機膜１３について、膜の広がる二次元方向を「面方向」といい、有機膜１３の膜厚の方向を「積層方向」という。 In the following, with respect to the organic film 13, the two-dimensional direction in which the film spreads is referred to as the "plane direction", and the direction of the film thickness of the organic film 13 is referred to as the "stacking direction".
　有機膜１３は、第１電極１２の面上に形成され、次の特徴を有する。
（１）有機膜１３は、酸化還元活性を有するπ型有機分子を含む。
（２）π型有機分子は、有機膜１３の積層方向に、π－πスタッキングの状態である。
（３）有機膜１３に含まれるπ型有機分子は、異方性の配向を示す。 The organic film 13 is formed on the surface of the first electrode 12 and has the following characteristics.
(1) The organic film 13 contains a π-type organic molecule having a redox activity.
(2) The π-type organic molecule is in a π-π stacking state in the stacking direction of the organic film 13.
(3) The π-type organic molecule contained in the organic film 13 exhibits an anisotropic orientation.
　ここで、π－πスタッキングの状態とは、π型有機分子がπ－πスタッキングによる分子間相互作用により、分子を構成する原子が積層方向に沿って自己整列している状態を意味する。例えば、芳香族有機分子の少なくとも２つの芳香環が重なって配置した状態、または僅かずつずれて配置した状態の双方を意味する。 Here, the state of π-π stacking means a state in which the atoms constituting the molecule are self-aligned along the stacking direction due to the intermolecular interaction of π-type organic molecules by π-π stacking. For example, it means both a state in which at least two aromatic rings of aromatic organic molecules are arranged overlapping each other, or a state in which at least two aromatic rings are arranged slightly offset.
　異方性の配向とは、有機膜１３に含まれるπ型有機分子またはその結晶が整列した状態を意味する。 Anisotropic orientation means a state in which π-type organic molecules contained in the organic film 13 or their crystals are aligned.
　複数の第２電極１４は、例えば金Ａｕを電極材料として、所定の可変抵抗セル（メモリセル）の配列パターンに従って有機膜１３の面上にパターン形成される。 The plurality of second electrodes 14 are patterned on the surface of the organic film 13 according to the arrangement pattern of predetermined variable resistance cells (memory cells) using, for example, gold Au as an electrode material.
　このような構成の可変抵抗デバイス１０では、データ記録・データ消去・データ読み出しのための回路（不図示）および配線パターン（不図示）によって、共通電圧Ｖｏが第１電極１２に与えられ、個別に制御された制御電圧Ｖｘが複数の第２電極１４それぞれに与えられる。 In the variable resistance device 10 having such a configuration, a common voltage Vo is applied to the first electrode 12 individually by a circuit (not shown) and a wiring pattern (not shown) for data recording, data erasing, and data reading. A controlled control voltage Vx is applied to each of the plurality of second electrodes 14.
　以上の酸化還元活性、異方性の配向、およびπ－πスタッキングの両条件が揃うことにより、有機膜１３の積層方向にはπ型有機分子が原子単位に自己整列して電流（キャリア）の伝搬路が形成される。この伝搬路内を酸化還元するなどしてキャリア導入やキャリア排出を行うことにより、有機膜１３の積層方向には抵抗変化（高伝導状態・低伝導状態）が生じるようになると考えられる。 By satisfying both the above redox activity, anisotropic orientation, and π-π stacking conditions, π-type organic molecules are self-aligned in atomic units in the stacking direction of the organic film 13, and the current (carrier) A propagation path is formed. It is considered that resistance changes (high conduction state / low conduction state) occur in the stacking direction of the organic film 13 by introducing carriers or discharging carriers by redoxing in the propagation path.
　《π型有機分子の説明》
　次に、π型有機分子について説明する。 << Explanation of π-type organic molecules >>
Next, the π-type organic molecule will be described.
　図２は、有機膜１３に含まれるπ型有機分子の一般式を示す図である。
　このπ型有機分子の一般式の中央には、３環からなってπ電子共役系を有する1,3-diazaphenalenyl（ジアザフェナレニル）を有する。 FIG. 2 is a diagram showing a general formula of a π-type organic molecule contained in the organic film 13.
At the center of the general formula of this π-type organic molecule is 1,3-diazaphenalenyl, which is composed of three rings and has a π-electron conjugated system.
　図３は、この1,3-diazaphenalenylの酸化還元活性を説明する模式図である。
　同図に示すように、1,3-diazaphenalenylをベースとするπ型有機分子は酸化還元活性を有する。 FIG. 3 is a schematic diagram illustrating the redox activity of 1,3-diazaphenalenyl.
As shown in the figure, the 1,3-diazaphenalenyl-based π-type organic molecule has redox activity.
　さらに、この1,3-diazaphenalenylは、１，３位にアクセプター（Ｎ）およびプロトンドナー（ＮＨ）となる官能基を備える。 Furthermore, this 1,3-diazaphenalenyl has functional groups that serve as acceptors (N) and proton donors (NH) at positions 1 and 3.
　この構造により、π型有機分子は、酸化還元活性に加えて、プロトン授受能や電子ドナー性も有する。 Due to this structure, the π-type organic molecule has proton transfer ability and electron donor property in addition to redox activity.
　また、1,3-diazaphenalenylは分子間に水素結合を形成することが特徴で、集積された分子間のネットワークが構築可能になる。 In addition, 1,3-diazaphenalenyl is characterized by forming hydrogen bonds between molecules, which makes it possible to construct an integrated intermolecular network.
　この1,3-diazaphenalenylの２，５，８位には、Ｙ１，Ｙ２，Ｙ３がそれぞれ配置される。 Y1, Y2, Y3 are placed in the 2, 5 and 8 positions of this 1,3-diazaphenalenyl, respectively.
　Ｙ１～Ｙ３それぞれは、炭素数1から６０の飽和又は不飽和の炭化水素基であって、これら炭化水素基は１つ又は２つ以上の置換基を有してもよい。また、これら炭化水素基の中の１つ又は２つ以上の炭素原子は、酸素原子、硫黄原子、ケイ素原子、－ＮＲ－（ここで、Ｒは、水素原子、炭素数１～１０のアルキル基、又は炭素数６～３０のアリール基を表す）、－ＮＲ２、芳香族基、水酸基、カルボン酸で置換されていてもよい。なお、これらのＹ１～Ｙ３は、同一又は異なっていてもよい。 Each of Y1 to Y3 is a saturated or unsaturated hydrocarbon group having 1 to 60 carbon atoms, and these hydrocarbon groups may have one or more substituents. Further, one or more carbon atoms among these hydrocarbon groups are an oxygen atom, a sulfur atom, a silicon atom, and -NR- (where R is a hydrogen atom and an alkyl group having 1 to 10 carbon atoms. , Or an aryl group having 6 to 30 carbon atoms), −NR2, an aromatic group, a hydroxyl group, or a carboxylic acid. In addition, these Y1 to Y3 may be the same or different.
　《ＴＰＤＡＰの説明》
　続いて、π型有機分子の代表例として、ＴＰＤＡＰについて説明する。 << Explanation of TPDAP >>
Subsequently, TPDAP will be described as a representative example of the π-type organic molecule.
　図４は、ＴＰＤＡＰと呼ばれる2,5,8-tri(4-pyridyl)1,3-diazaphenaleneの分子構造を示す図である。
　同図において、1,3-diazaphenalenylの２，５，８位には、Ｙ１～Ｙ３として4-pyridyl（ピリジル）がそれぞれ配置される。 FIG. 4 is a diagram showing the molecular structure of 2,5,8-tri (4-pyridyl) 1,3-diazaphenalene called TPDAP.
In the figure, 4-pyridyl is arranged as Y1 to Y3 at the 2, 5 and 8 positions of 1,3-diazaphenalenyl, respectively.
　図５は、有機膜１３の面方向におけるＴＰＤＡＰの分子間のネットワークを示す図である。 FIG. 5 is a diagram showing an intermolecular network of TPDAP in the plane direction of the organic film 13.
　同図に示すように、ＴＰＤＡＰの分子の面方向には、ＮＨ…ＮタイプやＣＨ…ＮタイプによるＨ…Ｎの水素結合が作用し、密に集積されたネットワークが構成される。 As shown in the figure, hydrogen bonds of H ... N due to NH ... N type and CH ... N type act in the plane direction of the molecule of TPDAP to form a densely integrated network.
　図６は、有機膜１３の積層方向におけるＴＰＤＡＰの状態を示す図である。
　同図に示すように、ＴＰＤＡＰの結晶内では、π－πスタッキングの作用により分子を構成する原子が積層方向に自己整列するため、密に積層される。このように積層方向に自己整列して密に積層することにより、電流（キャリア）の伝搬路が積層方向に形成可能になる。 FIG. 6 is a diagram showing a state of TPDAP in the stacking direction of the organic film 13.
As shown in the figure, in the crystal of TPDAP, the atoms constituting the molecule are self-aligned in the stacking direction by the action of π-π stacking, so that they are densely stacked. By self-aligning in the stacking direction and densely stacking in this way, a current (carrier) propagation path can be formed in the stacking direction.
　なお、このようなＴＰＤＡＰの生成方法については、次の文献に例示がある。 An example of such a method for generating TPDAP is given in the following document.
　Jin Young Koo他『Redox-active Diazaphenalenyl-based Molecule and Neutral Radical Formation』，The Chemical Society of Japan，Chem. Lett. 2015, 44, 1131頁－1133頁 Jin Young Koo et al. "Redox-active Diazaphenalenyl-based Molecule and Neutral Radical Formation", The Chemical Society of Japan, Chem. Lett. 2015, 44, pp. 1131-1133
　《有機膜１３の成膜方法》
　次に、実施例１における有機膜１３の膜生成について説明する。 << Method of forming the organic film 13 >>
Next, the film formation of the organic film 13 in Example 1 will be described.
　図７は、ＴＰＤＡＰを膜材料として有機膜１３を生成する方法を説明する図である。
　同図において、蒸着装置２０１は、高真空ポンプ２０２と、ＴＰＤＡＰのサンプル２０３を配置したフィラメントボート２０４と、基板１１を配置した保持具２０５を備える。 FIG. 7 is a diagram illustrating a method of forming an organic film 13 using TPDAP as a film material.
In the figure, the vapor deposition apparatus 201 includes a high vacuum pump 202, a filament boat 204 on which a sample 203 of TPDAP is arranged, and a holder 205 on which a substrate 11 is arranged.
　高真空ポンプ２０２は、蒸着装置２０１内を例えば１Ｅ－６Ｔｏｒｒ程度の真空レベルに遷移させる。 The high vacuum pump 202 transitions the inside of the vapor deposition apparatus 201 to a vacuum level of, for example, about 1E-6 Torr.
　この状態で、フィラメントボート２０４は、ＴＰＤＡＰのサンプル２０３を、例えば２３０°Ｃ程度に加熱して蒸散させる。 In this state, the filament boat 204 heats the sample 203 of TPDAP to, for example, about 230 ° C. and evaporates it.
　蒸散されたＴＰＤＡＰの結晶は、基板１１の表面に蒸着し、有機膜１３を生成する。 The vaporized TPDAP crystals are deposited on the surface of the substrate 11 to form an organic film 13.
　この場合、蒸散密度および蒸着時間の調節により有機膜１３の膜厚が設定される。 In this case, the film thickness of the organic film 13 is set by adjusting the transpiration density and the vapor deposition time.
　さらに、保持具２０５を介して基板１１の温度を設定して有機膜１３の形成温度Ｔｓを調節することにより、有機膜１３の結晶や分子の配向をコントロールすることができる。
　ここでは、形成温度Ｔｓ＝８０°Ｃと、形成温度Ｔｓ＝２５°Ｃとの２例について説明する。 Further, by setting the temperature of the substrate 11 via the holder 205 and adjusting the formation temperature Ts of the organic film 13, the orientation of the crystals and molecules of the organic film 13 can be controlled.
Here, two examples of the formation temperature Ts = 80 ° C and the formation temperature Ts = 25 ° C will be described.
　図８の上段［Ａ］は、形成温度Ｔｓ＝８０°Ｃの条件で生成された有機膜１３について、微小角入射広角Ｘ線散乱（以下「ＧＩＷＡＸＳ」ともいう）を実測した２次元パターンを示す図である。 The upper part [A] of FIG. 8 shows a two-dimensional pattern obtained by actually measuring micro-angle incident wide-angle X-ray scattering (hereinafter, also referred to as “GIWAXS”) for the organic film 13 formed under the condition of formation temperature Ts = 80 ° C. It is a figure.
　形成温度Ｔｓ＝８０°Ｃの条件では、ＧＩＷＡＸＳの２次元パターンにおいてＸ線が広角に散乱していることから、図８の下段［Ｂ］に模式的に示すように、有機膜１３の配向は、積層方向に揃わない等方性を示すものと認められる。 Under the condition of the formation temperature Ts = 80 ° C., X-rays are scattered at a wide angle in the two-dimensional pattern of GIWAXS. Therefore, as schematically shown in the lower part [B] of FIG. 8, the orientation of the organic film 13 is , It is recognized that it shows isotropicity that is not aligned in the stacking direction.
　一方、図９の上段［Ａ］は、形成温度Ｔｓ＝２５°Ｃの条件で生成された有機膜１３について、微小角入射広角Ｘ線散乱を実測した２次元パターンを示す図である。 On the other hand, the upper part [A] of FIG. 9 is a diagram showing a two-dimensional pattern in which micro-angle incident wide-angle X-ray scattering is actually measured for the organic film 13 formed under the condition of formation temperature Ts = 25 ° C.
　形成温度Ｔｓ＝２５°Ｃの条件では、ＧＩＷＡＸＳの２次元パターンにおいてＸ線の散乱が小さいことから、図９の下段［Ｂ］に模式的に示すように、有機膜１３の配向は、積層方向に整列した異方性を示すものと認められる。この異方性の配向を示す有機膜１３の内部では、積層方向のπ－πスタッキングの作用が相乗し、ＴＰＤＡＰ分子を構成する原子が積層方向に自己整列する。 Under the condition of the formation temperature Ts = 25 ° C, the scattering of X-rays is small in the two-dimensional pattern of GIWAXS. Therefore, as schematically shown in the lower part [B] of FIG. 9, the orientation of the organic film 13 is the stacking direction. It is recognized that it shows anisotropy aligned with. Inside the organic film 13 exhibiting this anisotropic orientation, the action of π-π stacking in the stacking direction is synergistic, and the atoms constituting the TPDAP molecule are self-aligned in the stacking direction.
　このように、有機膜１３の形成温度により、異方性の配向をコントロールすることが可能になる。 In this way, the anisotropic orientation can be controlled by the formation temperature of the organic film 13.
　《配向状態による有機膜１３の電気的特性の違い》
　続いて、配向状態による有機膜１３の電気的特性の違いについて説明する。 << Difference in electrical characteristics of organic film 13 depending on orientation state >>
Subsequently, the difference in the electrical characteristics of the organic film 13 depending on the orientation state will be described.
　図１０の上段［Ａ］は、等方性の配向を示す有機膜１３について、積層方向の電圧－電流特性を測定した結果である。同図に示されるように、等方性の有機膜１３では、積層方向の電圧－電流特性に非連続な臨界変化は生じない。 The upper part [A] of FIG. 10 shows the results of measuring the voltage-current characteristics in the stacking direction of the organic film 13 showing an isotropic orientation. As shown in the figure, in the isotropic organic film 13, a discontinuous critical change does not occur in the voltage-current characteristics in the stacking direction.
　一方、図１０の上段［Ｂ］は、異方性の配向を示す有機膜１３について、積層方向の電圧－電流特性を測定した結果である。同図の横軸は有機膜１３の積層方向に印加した電圧値を示し、同図の縦軸は有機膜１３の積層方向に流れる電流の大きさ（絶対値）を示す。同図に示されるように、異方性の有機膜１３に限って、積層方向の電圧－電流特性に非連続な臨界変化が生じる。 On the other hand, the upper part [B] of FIG. 10 shows the results of measuring the voltage-current characteristics in the stacking direction of the organic film 13 showing an anisotropic orientation. The horizontal axis of the figure shows the voltage value applied in the stacking direction of the organic film 13, and the vertical axis of the figure shows the magnitude (absolute value) of the current flowing in the stacking direction of the organic film 13. As shown in the figure, a discontinuous critical change occurs in the voltage-current characteristics in the stacking direction only in the anisotropic organic film 13.
　《可変抵抗デバイス１０の基本動作》
　可変抵抗デバイス１０は、第１電極１２と第２電極１４によって、異方性の有機膜１３に対し積層方向に電圧を印加するため、図１０［Ｂ］に示す電圧－電流特性に従って動作する。 << Basic operation of variable resistance device 10 >>
Since the variable resistance device 10 applies a voltage to the anisotropic organic film 13 in the stacking direction by the first electrode 12 and the second electrode 14, the variable resistance device 10 operates according to the voltage-current characteristics shown in FIG. 10 [B].
　図１１は、この可変抵抗デバイス１０の基本動作を説明する図である。 FIG. 11 is a diagram illustrating the basic operation of the variable resistance device 10.
　同図において、横軸は、第２電極１４と第１電極１２との間の電圧差（Ｖｘ－Ｖｏ）を示す。縦軸は、有機膜１３の積層方向を介して第２電極１４と第１電極１２との間に流れる電流の大きさ（絶対値）を示す。 In the figure, the horizontal axis indicates the voltage difference (Vx-Vo) between the second electrode 14 and the first electrode 12. The vertical axis indicates the magnitude (absolute value) of the current flowing between the second electrode 14 and the first electrode 12 via the stacking direction of the organic film 13.
　可変抵抗デバイス１０の電気的な初期状態では、電圧差（Ｖｘ－Ｖｏ）＝０．５［Ｖ］の印加に対して、１ナノアンペア程度の微弱な漏れ電流しか流れず、低伝導状態を示す。 In the initial electrical state of the variable resistance device 10, only a weak leakage current of about 1 nanoampere flows with respect to the application of a voltage difference (Vx-Vo) = 0.5 [V], indicating a low conduction state. ..
　この低伝導状態は、第１電極１２と第２電極１４とを電気的に短絡しても、オープン状態にしても、再現されるために不揮発性の性質を有する。 This low conduction state has a non-volatile property because it can be reproduced regardless of whether the first electrode 12 and the second electrode 14 are electrically short-circuited or opened.
　この低伝導状態において、第２電極１４と第１電極１２との間にターンオン電圧（図１１では約３Ｖ）を印加すると、電圧－電流特性に非連続な臨界変化が生じ、高伝導状態に移行する。 In this low conduction state, when a turn-on voltage (about 3V in FIG. 11) is applied between the second electrode 14 and the first electrode 12, a discontinuous critical change occurs in the voltage-current characteristics, and the state shifts to the high conduction state. To do.
　この高伝導状態では、電圧差（Ｖｘ－Ｖｏ）＝０．５［Ｖ］の印加に対して、１ミリアンペア程度の電流が流れる。 In this high conduction state, a current of about 1 milliamperes flows with respect to the application of a voltage difference (Vx-Vo) = 0.5 [V].
　この高伝導状態も、第１電極１２と第２電極１４とを電気的に短絡しても、オープン状態にしても、再現されるために不揮発性の性質を有する。 This high conduction state also has a non-volatile property because it can be reproduced regardless of whether the first electrode 12 and the second electrode 14 are electrically short-circuited or opened.
　この高伝導状態において、第２電極１４と第１電極１２との間にターンオフ電圧（図１１では約－１．５Ｖ）を印加すると、電圧－電流特性に非連続な臨界変化が生じ、低伝導状態に復帰する。 In this high conduction state, when a turn-off voltage (about -1.5V in FIG. 11) is applied between the second electrode 14 and the first electrode 12, a discontinuous critical change occurs in the voltage-current characteristics, resulting in low conduction. Return to the state.
　この場合、低伝導状態と高伝導状態の抵抗比は、「１０の６乗」倍ほどの大きなオンオフ抵抗比を示す。 In this case, the resistivity ratio between the low-conductivity state and the high-conductivity state shows a large on-off resistance ratio of about "10 to the 6th power".
　このように、可変抵抗デバイス１０は、図１１に示す矢印の向きに沿って低伝導状態と高伝導状態のサイクル軌道を経由し、状態遷移を繰り返す。
　このことは、酸化還元活性を有する有機膜の分子配列がメモリ効果を引き起こしていることが原因と考えられる。 In this way, the variable resistance device 10 repeats the state transition through the cycle orbits of the low conduction state and the high conduction state along the direction of the arrow shown in FIG.
It is considered that this is because the molecular arrangement of the organic film having redox activity causes the memory effect.
《有機膜１３の膜厚依存性》
　なお、前述したターンオン電圧およびターンオフ電圧は、図１２に示すように、有機膜１３の膜厚に依存して変化する。
　図１２は、図１１の場合と同様に第２電極１４と第１電極１２との間に電圧を印加した場合の有機膜の膜厚による電圧－電流特性を示す図である。
　図１２に示されるように、ＴＰＤＡＰ膜厚を６５ｎｍ、１００ｎｍ、１３０ｎｍと変化させた場合、膜厚６５ｎｍの場合は、ターンオン電圧が約２Ｖ強、ターンオフ電圧が約－１Ｖとなり、膜厚１００ｎｍの場合は、ターンオン電圧が約３Ｖ強、ターンオフ電圧が約－１．５Ｖとなり、膜厚１３０ｎｍの場合は、ターンオン電圧が約３．５Ｖ強、ターンオフ電圧が約－２Ｖとなる。
　このことから、本実施形態の可変抵抗デバイスには、電圧－電流特性に膜厚依存性があることがわかる。 << Dependence on film thickness of organic film 13 >>
As shown in FIG. 12, the above-mentioned turn-on voltage and turn-off voltage change depending on the film thickness of the organic film 13.
FIG. 12 is a diagram showing voltage-current characteristics due to the film thickness of the organic film when a voltage is applied between the second electrode 14 and the first electrode 12 as in the case of FIG.
As shown in FIG. 12, when the TPDAP film thickness is changed to 65 nm, 100 nm, and 130 nm, when the film thickness is 65 nm, the turn-on voltage is a little over 2 V, the turn-off voltage is about -1 V, and the film thickness is 100 nm. The turn-on voltage is a little over 3V and the turn-off voltage is about −1.5V, and when the film thickness is 130 nm, the turn-on voltage is a little over 3.5V and the turn-off voltage is about -2V.
From this, it can be seen that the variable resistance device of the present embodiment has a film thickness dependence on the voltage-current characteristics.
　そのため、有機膜１３を薄膜化することにより、可変抵抗デバイス１０の駆動電圧を低電圧化することが可能になる。また、有機膜１３を厚膜化することにより、可変抵抗デバイス１０を抵抗、スイッチ、または記録媒体として利用可能な電圧範囲を拡大することが可能になる。
　そして、ターンオフ電圧にも膜厚依存性があることから、本実施形態の可変抵抗デバイスの抵抗可変メカニズムは、有機膜中に金属イオンが移動し、細いフィラメントが形成されて電極間がつながるメカニズム（いわゆる「フィラメント形成機構」）ではないことが推測される。 Therefore, by thinning the organic film 13, the drive voltage of the variable resistance device 10 can be reduced. Further, by thickening the organic film 13, it becomes possible to expand the voltage range in which the variable resistance device 10 can be used as a resistor, a switch, or a recording medium.
Since the turn-off voltage also depends on the film thickness, the resistance variable mechanism of the variable resistance device of the present embodiment is a mechanism in which metal ions move in the organic film to form thin filaments and connect the electrodes ( It is presumed that this is not the so-called "filament formation mechanism").
《セルサイズ依存性》
　図１３は、図１１の場合と同様に第２電極１４と第１電極１２との間に電圧を印加した場合のセルサイズによる電圧－電流特性を示す図である。
　図１２に示されるように、セルサイズを５０μｍ、１００μｍと変化させた場合、セルサイズ５０μｍの場合は、ターンオン電圧が約３.５Ｖ、ターンオフ電圧が約－１．５Ｖとなり、セルサイズ１００μｍの場合は、ターンオン電圧が約３．７Ｖ強、ターンオフ電圧が約－１．７Ｖとなることがわかる。
　ちなみに、本実施形態におけるセルサイズとは、図１に示す第２電極１４の直径を示している。
　このことから、本実施形態の可変抵抗デバイスには、電圧－電流特性にセルサイズ依存性があることもわかる。 《Cell size dependency》
FIG. 13 is a diagram showing voltage-current characteristics according to cell size when a voltage is applied between the second electrode 14 and the first electrode 12 as in the case of FIG.
As shown in FIG. 12, when the cell size is changed to 50 μm and 100 μm, the turn-on voltage is about 3.5 V and the turn-off voltage is about -1.5 V when the cell size is 50 μm, and when the cell size is 100 μm. It can be seen that the turn-on voltage is a little over 3.7V and the turn-off voltage is about -1.7V.
Incidentally, the cell size in the present embodiment indicates the diameter of the second electrode 14 shown in FIG.
From this, it can be seen that the variable resistance device of the present embodiment has a cell size dependence on the voltage-current characteristic.
　《有機膜１３の面方向の絶縁特性》
　続いて、異方性の有機膜１３について、面方向の絶縁特性を説明する。 << Insulation characteristics of the organic film 13 in the plane direction >>
Subsequently, the insulating characteristics in the plane direction of the anisotropic organic film 13 will be described.
　図１４は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）の面方向における電圧－電流特性を測定した結果を示す図である。異方性の有機膜１３は、面方向には極微弱な漏れ電流しか流れず、優れた絶縁特性を示す。 FIG. 14 is a diagram showing the results of measuring the voltage-current characteristics of the anisotropic organic film 13 (aniso-TPDAP) in the plane direction. The anisotropic organic film 13 causes only a very weak leakage current to flow in the plane direction, and exhibits excellent insulation characteristics.
　このように、有機膜１３それ自体が面方向の絶縁特性を有するため、可変抵抗デバイス１０の可変抵抗セル（メモリセル）の隣接境界域（図１に示す第２電極１４の配列の隙間）には、周囲から電気的に隔離するための絶縁構造を別途設ける必要がない。そのため、可変抵抗デバイス１０は、図１に示すように、簡易な基本構造で構成することができる。 As described above, since the organic film 13 itself has the insulating property in the plane direction, it is located in the adjacent boundary region (gap in the arrangement of the second electrode 14 shown in FIG. 1) of the variable resistance cell (memory cell) of the variable resistance device 10. Does not need to be separately provided with an insulating structure for electrically isolating it from the surroundings. Therefore, the variable resistance device 10 can be configured with a simple basic structure as shown in FIG.
　その結果、可変抵抗セル（メモリセル）の微細化および高集積化が容易になる。特に、aniso-ＴＰＤＡＰが積層方向に整列する分子の列単位に独立して機能し得ることを勘案すると、原理的には可変抵抗セル（メモリセル）の第２電極１４の面積を分子サイズのオーダーまで微細化し高集積化することが可能になる。 As a result, the variable resistance cell (memory cell) can be easily miniaturized and highly integrated. In particular, considering that aniso-TPDAP can function independently for each row of molecules aligned in the stacking direction, in principle, the area of the second electrode 14 of the variable resistance cell (memory cell) is on the order of the molecular size. It becomes possible to make it finer and highly integrated.
　《不揮発性の経時安定性》
　図１５は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）について、不揮発性の経時安定性を測定した結果を示す図である。 << Non-volatile stability over time >>
FIG. 15 is a diagram showing the results of measuring the non-volatile stability over time of the anisotropic organic film 13 (aniso-TPDAP).
　同図に示すように、低伝導状態および高伝導状態のいずれにおいても、計測された時間範囲において電流量に目立った変化は見られず、可変抵抗デバイス１０としての不揮発性は良好に維持されている。 As shown in the figure, no noticeable change in the amount of current was observed in the measured time range in both the low conduction state and the high conduction state, and the non-volatility of the variable resistance device 10 was well maintained. There is.
　《不揮発性の高温耐久性》
　図１６は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）について、高温下での耐久性を示す図である。コンピュータの動作する摂氏１２０度の高温下であっても、低伝導状態および高伝導状態のいずれにおいても、計測された時間範囲において電流量に目立った変化は見られず、可変抵抗デバイス１０としての不揮発性は良好に維持されている。 《Non-volatile high temperature durability》
FIG. 16 is a diagram showing the durability of the anisotropic organic film 13 (aniso-TPDAP) at high temperatures. Even at a high temperature of 120 degrees Celsius where the computer operates, no noticeable change in the amount of current was observed in the measured time range in both the low conduction state and the high conduction state, and the variable resistance device 10 was used. Non-volatileity is well maintained.
　《書き換えの耐久性》
　図１７は、異方性の有機膜１３（aniso-ＴＰＤＡＰ）について書き換えの耐久性を測定した結果を示す図である。
　同図に示すように、低伝導状態および高伝導状態のいずれにおいても、計測された書き換え回数の範囲において、電流量に目立った変化は見られず、書き換え（ターンオンとターンオフ）を繰り返しても、可変抵抗デバイス１０としての耐久性は良好に維持されている。 《Rewriting durability》
FIG. 17 is a diagram showing the results of measuring the rewriting durability of the anisotropic organic film 13 (aniso-TPDAP).
As shown in the figure, in both the low conduction state and the high conduction state, no noticeable change was observed in the amount of current within the measured number of rewrites, and even if the rewrites (turn-on and turn-off) were repeated, The durability of the variable resistance device 10 is well maintained.
　《可変抵抗デバイス１０の大気安定性》
　図１８は、有機膜１３（aniso-ＴＰＤＡＰ）を、水蒸気を含ませた窒素ガスに繰り返し晒して、水蒸気下での大気安定性を測定した結果を示す図である。
　同図に示すように、水蒸気を含ませた窒素ガスの有無にかかわらず、有機膜１３に流れる電流量に目立った変化は見られない。したがって、可変抵抗デバイス１０は、水蒸気下において高い大気安定性を示す。 << Atmospheric stability of variable resistance device 10 >>
FIG. 18 is a diagram showing the results of measuring the atmospheric stability under water vapor by repeatedly exposing the organic film 13 (aniso-TPDAP) to nitrogen gas containing water vapor.
As shown in the figure, there is no noticeable change in the amount of current flowing through the organic film 13 regardless of the presence or absence of nitrogen gas containing water vapor. Therefore, the variable resistance device 10 exhibits high atmospheric stability under water vapor.
　このような結果は、有機膜１３（aniso-ＴＰＤＡＰ）の分子間ネットワークが高充填構造であるために外部分子の侵入スペースが少なく、空気中の分子が有機膜１３の内部に侵入しにくいためと考えられる。 Such a result is because the intermolecular network of the organic membrane 13 (aniso-TPDP) has a highly packed structure, so that the space for the external molecules to enter is small, and the molecules in the air do not easily penetrate the inside of the organic membrane 13. Conceivable.
　さらに、有機膜１３において可変抵抗セル（メモリセル）を形成する各領域は、第２電極１４で実質的に被覆されているためとも考えられる。仮に、第２電極１４の配列の隙間から空気中の分子が有機膜１３（aniso-ＴＰＤＡＰ）の内部に侵入しても、有機膜１３（aniso-ＴＰＤＡＰ）それ自体の面方向の絶縁特性ゆえに可変抵抗セル（メモリセル）の電気的特性に影響を及ぼしにくいためとも考えられる。 Further, it is also considered that each region forming the variable resistance cell (memory cell) in the organic film 13 is substantially covered with the second electrode 14. Even if molecules in the air enter the inside of the organic film 13 (aniso-TPDAP) through the gaps in the arrangement of the second electrodes 14, they are variable due to the insulation characteristics of the organic film 13 (aniso-TPDAP) itself in the plane direction. It is also considered that this is because it does not easily affect the electrical characteristics of the resistance cell (memory cell).
　このような大気安定性により、デバイスの製造過程において、有機膜１３（aniso-ＴＰＤＡＰ）は空気中の分子により汚染されにくくなるため、可変抵抗デバイス１０の製造時の空気洗浄レベルを低くできる、製造歩留りが高くなるなどの実用的な利点がある。 Due to such atmospheric stability, the organic membrane 13 (aniso-TPDAP) is less likely to be contaminated by molecules in the air during the manufacturing process of the device, so that the air cleaning level at the time of manufacturing the variable resistance device 10 can be lowered. There are practical advantages such as high yield.
　《可変抵抗デバイス１０のメモリ集積デバイスとしての利用》
　図１９は、可変抵抗デバイス１０をメモリ集積デバイスとして使用する際の電圧配分の一例を示す図である。
　同図に示すように、第１電極１２には、共通電圧Ｖｏ＝１．７５［Ｖ］が印加される。 << Use of variable resistance device 10 as a memory integrated device >>
FIG. 19 is a diagram showing an example of voltage distribution when the variable resistance device 10 is used as a memory integrated device.
As shown in the figure, a common voltage Vo = 1.75 [V] is applied to the first electrode 12.
　メモリ読み出し時、第２電極１４には、制御電圧Ｖｘ＝２．２５［Ｖ］が印加される。この状態で有機膜１３の積層方向にはＶｘ－Ｖｏ＝０．５［Ｖ］の読み出し電圧が印加される。このときに第２電極１４がカバーするメモリセルに流れる電流を検出して二値判定することにより、当該メモリセルの記憶データ（高伝導状態・低伝導状態）が読み出される。 At the time of reading the memory, the control voltage Vx = 2.25 [V] is applied to the second electrode 14. In this state, a read voltage of Vx—Vo = 0.5 [V] is applied in the stacking direction of the organic film 13. At this time, by detecting the current flowing through the memory cell covered by the second electrode 14 and making a binary determination, the stored data (high conduction state / low conduction state) of the memory cell is read out.
　また、メモリのセット（書き込み）時、第２電極１４には、制御電圧Ｖｘ＝４．７５［Ｖ］が印加される。この状態で有機膜１３の積層方向にはＶｘ－Ｖｏ＝３．０［Ｖ］のターンオン電圧が印加される。このときに第２電極１４がカバーするメモリセルは、不揮発的に高伝導状態に移行し、当該メモリセルの記憶データはセットされる。 Further, when the memory is set (written), the control voltage Vx = 4.75 [V] is applied to the second electrode 14. In this state, a turn-on voltage of Vx—Vo = 3.0 [V] is applied in the stacking direction of the organic film 13. At this time, the memory cell covered by the second electrode 14 non-volatilely shifts to the high conduction state, and the storage data of the memory cell is set.
　一方、メモリのリセット（消去）時、第２電極１４には、制御電圧Ｖｘ＝０．２５［Ｖ］が印加される。この状態で有機膜１３の積層方向にはＶｘ－Ｖｏ＝－１．５［Ｖ］のターンオフ電圧が印加される。このときに第２電極１４がカバーするメモリセルは、不揮発的に低伝導状態に移行し、当該メモリセルの記憶データはリセットされる。 On the other hand, when the memory is reset (erased), the control voltage Vx = 0.25 [V] is applied to the second electrode 14. In this state, a turn-off voltage of Vx−Vo = −1.5 [V] is applied in the stacking direction of the organic film 13. At this time, the memory cell covered by the second electrode 14 non-volatilely shifts to the low conduction state, and the stored data of the memory cell is reset.
　《可変抵抗デバイス１０のスイッチングデバイスとしての利用》
　図１に示した可変抵抗デバイス１０は、スイッチングデバイスとしての利用も可能である。この場合、第１電極１２と第２電極１４との間にターンオン電圧およびターンオフ電圧を超えない範囲で電圧または電流を与えることにより、有機膜１３の高伝導状態をスイッチＯＮ状態として利用し、有機膜１３の低伝導状態をスイッチＯＦＦ状態として利用する。 << Use of variable resistance device 10 as a switching device >>
The variable resistance device 10 shown in FIG. 1 can also be used as a switching device. In this case, by applying a voltage or current between the first electrode 12 and the second electrode 14 within a range not exceeding the turn-on voltage and the turn-off voltage, the high conduction state of the organic film 13 is utilized as the switch ON state, and the organic film 13 is organic. The low conduction state of the film 13 is used as the switch OFF state.
　ちなみに、スイッチＯＮ状態のＯＮ抵抗を下げたり、ＯＮ電流の絶対定格値を大きくしたい場合には、複数の第２電極１４を並列に接続する、あるいは第２電極１４の電極面積を拡大するといった調整が可能である。 By the way, when it is desired to lower the ON resistance in the switch ON state or increase the absolute rated value of the ON current, adjustments such as connecting a plurality of second electrodes 14 in parallel or expanding the electrode area of the second electrode 14 are performed. Is possible.
　実施例２では、可変抵抗デバイスをトランジスタに応用する実施例について説明する。
　図２０の上段［Ａ］は、有機電界効果トランジスタ３００の構成を示す模式図である。 In the second embodiment, an embodiment in which the variable resistance device is applied to a transistor will be described.
The upper part [A] of FIG. 20 is a schematic view showing the configuration of the organic field effect transistor 300.
　同図において、有機電界効果トランジスタ３００は、N-typeＳｉ層からなるゲートＧと、ＳｉＯ２からなる絶縁層３０２と、第１電極としてチャネル経路を形成可能なグラフェン３０３と、aniso-ＴＰＤＡＰを含む有機膜３０４と、有機膜３０４の上面に金Ａuパターンからなる第２電極としてのドレインＤおよびソースＳとを備える。 In the figure, the organic field effect transistor 300 includes a gate G made of an N-type Si layer, an insulating layer 302 made of SiO 2 , a graphene 303 capable of forming a channel path as a first electrode, and aniso-TPDAP. The film 304 is provided with a drain D and a source S as a second electrode having a gold Au pattern on the upper surface of the organic film 304.
　この有機膜３０４は、実施例１の有機膜１３と同じであるため、ここでの重複説明を省略する。 Since this organic film 304 is the same as the organic film 13 of Example 1, duplicate description here will be omitted.
　ゲートＧおよび絶縁層３０２は、グラフェン３０３のチャネル経路を制御するゲート機構として機能する。 The gate G and the insulating layer 302 function as a gate mechanism for controlling the channel path of the graphene 303.
　一方、ドレインＤとソースＳとの間には、電圧Ｖｄｓが印加される。
　この状態で、ゲートＧに電圧を印加して、グラフェン３０３のチャネル経路を開方向に変化させると、グラフェン３０３の面方向の等価抵抗が低下する。 On the other hand, a voltage Vds is applied between the drain D and the source S.
In this state, when a voltage is applied to the gate G to change the channel path of the graphene 303 in the open direction, the equivalent resistance in the plane direction of the graphene 303 decreases.
　そのため、ドレインＤとソースＳとの間に印加される電圧Ｖｄｓの内で、グラフェン３０３に分圧される電圧分が低下する。 Therefore, within the voltage Vds applied between the drain D and the source S, the voltage divided by the graphene 303 decreases.
　この作用により、電圧Ｖｄｓが印加される直列経路において、有機膜３０４の積層方向に分圧されていた電圧が上昇し、有機膜３０４のターンオン電圧を超える。その結果、ドレインＤまたはソースＳの一方に接する有機膜３０４の積層方向がターンオンする。 Due to this action, in the series path to which the voltage Vds is applied, the voltage divided in the stacking direction of the organic film 304 rises and exceeds the turn-on voltage of the organic film 304. As a result, the stacking direction of the organic film 304 in contact with either the drain D or the source S turns on.
　すると、電圧Ｖｄｓは、ドレインＤまたはソースＳの他方に接する有機膜３０４の積層方向に集中的に印加され、有機膜３０４のターンオン電圧を超える。その結果、ドレインＤまたはソースＳの他方に接する有機膜３０４の積層方向もターンオンする。 Then, the voltage Vds is intensively applied in the stacking direction of the organic film 304 in contact with the drain D or the other of the source S, and exceeds the turn-on voltage of the organic film 304. As a result, the stacking direction of the organic film 304 in contact with the drain D or the other of the source S is also turned on.
　このように、ドレインＤまたはソースＳの両方に接する有機膜３０４の積層方向が共にターンオンする。この状態では、ゲートＧの印加電圧によってグラフェン３０３のチャネル制御を行って、ドレインＤに流れるドレイン電流を制御することが可能になる。 In this way, the stacking directions of the organic films 304 in contact with both the drain D and the source S are both turned on. In this state, the channel of graphene 303 can be controlled by the applied voltage of the gate G, and the drain current flowing through the drain D can be controlled.
　図２０の中段［Ｂ］は、有機電界効果トランジスタ３００のゲート電圧－ドレイン電流の特性を示す図である。 The middle stage [B] of FIG. 20 is a diagram showing the characteristics of the gate voltage-drain current of the organic field effect transistor 300.
　ターンオフ状態の有機膜３０４により、ゲート電圧の閾値電圧（約１２Ｖ）の直前では、ドレイン電流は殆ど流れない。しかし、ゲート電圧が閾値電圧を超えて有機膜３０４がターンオンすることにより、ドレイン電流は（１０の６乗）倍ほども急激に増加する。 Due to the organic film 304 in the turn-off state, almost no drain current flows immediately before the threshold voltage (about 12V) of the gate voltage. However, when the gate voltage exceeds the threshold voltage and the organic film 304 is turned on, the drain current rapidly increases by about (10 to the 6th power) times.
　一般に、グラフェンをチャネル経路に使用する有機電界効果トランジスタは、オンオフ電流比は低い。しかしながら、積層方向の電流バリア層としてaniso-ＴＰＤＡＰを含む有機膜３０４を追加することにより、オンオフ電流比を（１０の６乗）倍程度まで引き上げることが可能になる。 Generally, organic field effect transistors that use graphene in the channel path have a low on-off current ratio. However, by adding the organic film 304 containing aniso-TPDAP as the current barrier layer in the stacking direction, the on-off current ratio can be increased to about (10 to the 6th power) times.
　なお、図２０の下段［Ｃ］のデバイス構成については後述する。 The device configuration in the lower part [C] of FIG. 20 will be described later.
《実施例の補足事項》
　なお、実施例１，２では、有機膜１３を蒸着法により成膜している。しかしながら、本発明はこれに限定されない。例えば、π型有機分子を溶媒に溶かして溶液として基板１１に滴下ないし塗布し、溶液濃度や遠心力などによって有機膜１３の膜厚をコントロールしてもよい。ここで溶媒とは例えば一般的な有機溶媒を指し、π型有機分子を溶解するものであれば限定されない。 << Supplementary matters of the embodiment >>
In Examples 1 and 2, the organic film 13 is formed by a vapor deposition method. However, the present invention is not limited to this. For example, the π-type organic molecule may be dissolved in a solvent and dropped or applied to the substrate 11 as a solution, and the film thickness of the organic film 13 may be controlled by the solution concentration or centrifugal force. Here, the solvent refers to, for example, a general organic solvent, and is not limited as long as it dissolves π-type organic molecules.
　また、実施例１，２では、第１電極１２および第２電極１４との間に、ターンオン電圧およびターンオフ電圧を超えない範囲で読み出し電圧を印加することによって高伝導状態または低伝導状態を記憶データとして読み出している。しかしながら、本発明はこれに限定されない。例えば、第１電極１２および第２電極１４との間に、ターンオン電圧およびターンオフ電圧を超えない範囲で読み出し電流を流すことによって高伝導状態または低伝導状態を記憶データとして読み出してもよい。 Further, in Examples 1 and 2, the high conduction state or the low conduction state is stored as data by applying a read voltage between the first electrode 12 and the second electrode 14 within a range not exceeding the turn-on voltage and the turn-off voltage. Is read as. However, the present invention is not limited to this. For example, the high conduction state or the low conduction state may be read out as stored data by passing a read current between the first electrode 12 and the second electrode 14 within a range not exceeding the turn-on voltage and the turn-off voltage.
　さらに、実施例１，２では、複数の第２電極１４を設けることにより、可変抵抗デバイスを集積素子としている。しかしながら、本発明はこれに限定されない。第１電極および第２電極を１対のみ設けることにより、可変抵抗デバイスを単体素子としてもよい。 Further, in Examples 1 and 2, the variable resistance device is used as an integrated element by providing a plurality of second electrodes 14. However, the present invention is not limited to this. By providing only one pair of the first electrode and the second electrode, the variable resistance device may be a single element.
　なお、実施例２では、ドレインＤおよびソースＳの下に有機膜３０４を設ける。しかしながら、本発明はこれに限定されない。例えば、ドレインＤおよびソースＳの一方の下の有機膜３０４を省略してもよい（図２０の下段［Ｃ］を参照）。このような構成においても、ドレインＤおよびソースＳの他方の下の有機膜３０４が電流バリアとして機能するため、高いオンオフ電流比の有機電界効果トランジスタを得ることが可能になる。 In the second embodiment, the organic film 304 is provided under the drain D and the source S. However, the present invention is not limited to this. For example, the organic film 304 under one of the drain D and the source S may be omitted (see the lower part [C] of FIG. 20). Even in such a configuration, since the organic film 304 under the other of the drain D and the source S functions as a current barrier, it is possible to obtain an organic field effect transistor having a high on / off current ratio.
１０…可変抵抗デバイス、１１…基板、１２…第１電極、１３…有機膜、１４…第２電極、２０１…蒸着装置、２０２…高真空ポンプ、２０３…サンプル、２０４…フィラメントボート、２０５…保持具、３００…有機電界効果トランジスタ、３０２…絶縁層、３０３…グラフェン、３０４…有機膜、Ｄ…ドレイン、Ｇ…ゲート、Ｓ…ソース 10 ... variable resistance device, 11 ... substrate, 12 ... first electrode, 13 ... organic film, 14 ... second electrode, 201 ... vapor deposition equipment, 202 ... high vacuum pump, 203 ... sample, 204 ... filament boat, 205 ... holding Ingredients, 300 ... Organic field effect transistor, 302 ... Insulation layer, 303 ... Graphene, 304 ... Organic film, D ... Drain, G ... Gate, S ... Source

Claims (10)

  1. 　有機膜と、前記有機膜の両面を挟んで少なくとも一部が対向する第１電極および第２電極とを備え、
    　前記有機膜は、
    　　（１）酸化還元活性を有するπ型有機分子を含み、
    　　（２）前記π型有機分子は前記有機膜の積層方向にπ－πスタッキングの状態であり、
    　　（３）前記有機膜の内部の前記π型有機分子は異方性の配向である、
    　ことを特徴とする可変抵抗デバイス。     It is provided with an organic film and a first electrode and a second electrode that at least partially face each other with both sides of the organic film interposed therebetween.
    The organic film is
    (1) Contains π-type organic molecules with redox activity
    (2) The π-type organic molecule is in a state of π-π stacking in the stacking direction of the organic film.
    (3) The π-type organic molecule inside the organic film has an anisotropic orientation.
    A variable resistance device characterized by that.
  2. 　請求項１に記載の可変抵抗デバイスにおいて、
    　前記π型有機分子は、次の一般式で表される
    Figure JPOXMLDOC01-appb-C000001
     　ただし、式中のY１～Y3は、同一又は異なっていてもよく、それぞれ独立して、炭素数1から６０の飽和又は不飽和の炭化水素基を表し、当該炭化水素基は１つ又は２つ以上の置換基を有してもよく、また、当該炭化水素基の中の１つ又は２つ以上の炭素原子が酸素原子、硫黄原子、ケイ素原子、－ＮＲ－（ここで、Ｒは、水素原子、炭素数１～１０のアルキル基、又は炭素数６～３０のアリール基を表す。）、－ＮＲ２、芳香族基、水酸基、カルボン酸で置換されていてもよい、
    　ことを特徴とする可変抵抗デバイス。     In the variable resistance device according to claim 1,
    The π-type organic molecule is represented by the following general formula.
    Figure JPOXMLDOC01-appb-C000001
     However, Y1 to Y3 in the formula may be the same or different, and independently represent saturated or unsaturated hydrocarbon groups having 1 to 60 carbon atoms, and the number of the hydrocarbon groups is one or two. It may have the above substituents, and one or more carbon atoms in the hydrocarbon group are oxygen atom, sulfur atom, silicon atom, -NR- (where R is hydrogen). It may be substituted with an atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 30 carbon atoms), -NR2, an aromatic group, a hydroxyl group, or a carboxylic acid.
    A variable resistance device characterized by that.
  3. 　請求項１または２のいずれか一項に記載の可変抵抗デバイスにおいて、
    　前記有機膜の面方向に並ぶ前記π型有機分子の分子間にＨ…Ｎの水素結合を備える
    　ことを特徴とする可変抵抗デバイス。     In the variable resistance device according to any one of claims 1 or 2.
    A variable resistance device characterized by having H ... N hydrogen bonds between the molecules of the π-type organic molecules arranged in the plane direction of the organic film.
  4. 　請求項１～３のいずれか一項に記載の可変抵抗デバイスにおいて、
    　前記第１電極と前記第２電極との間にターンオン電圧を一旦印加することにより前記有機膜の積層方向を低伝導状態から高伝導状態に状態遷移させ、
    　前記第１電極と前記第２電極との間に前記ターンオン電圧と逆方向のターンオフ電圧を一旦印加することにより前記有機膜の積層方向を前記高伝導状態から前記低伝導状態に状態遷移させる
    　ことを特徴とする可変抵抗デバイス。     The variable resistance device according to any one of claims 1 to 3.
    By temporarily applying a turn-on voltage between the first electrode and the second electrode, the stacking direction of the organic film is changed from a low conduction state to a high conduction state.
    By once applying a turn-off voltage in the direction opposite to the turn-on voltage between the first electrode and the second electrode, the stacking direction of the organic film is changed from the high conduction state to the low conduction state. A variable resistance device that features.
  5. 　請求項４に記載の可変抵抗デバイスにおいて、
    　前記第１電極と前記第２電極との間に、前記ターンオン電圧および前記ターンオフ電圧を超えない範囲で電圧または電流を与えることにより、前記高伝導状態または前記低伝導状態を記憶データとして読み出すメモリデバイスとした
    　ことを特徴とする可変抵抗デバイス。     In the variable resistance device according to claim 4,
    A memory device that reads out the high conduction state or the low conduction state as storage data by applying a voltage or current between the first electrode and the second electrode within a range not exceeding the turn-on voltage and the turn-off voltage. A variable resistance device characterized by the fact that
  6. 　請求項５に記載の可変抵抗デバイスにおいて、
    　前記第１電極を前記有機膜の一方の面側に共通電位を与える共通電極として配置し、
    　前記第２電極を前記有機膜の他方の面側に個別の電位を与える複数の電極として配列することにより、
    　メモリ集積デバイスとした
    　ことを特徴とする可変抵抗デバイス。     In the variable resistance device according to claim 5,
    The first electrode is arranged as a common electrode that gives a common potential to one surface side of the organic film.
    By arranging the second electrode as a plurality of electrodes that give individual potentials to the other surface side of the organic film,
    A variable resistance device characterized by being a memory integrated device.
  7. 　請求項４に記載の可変抵抗デバイスにおいて、
    　前記第１電極と前記第２電極との間に、前記ターンオン電圧および前記ターンオフ電圧を超えない範囲で電圧または電流を与えることにより、前記高伝導状態をスイッチＯＮ状態として利用し、前記低伝導状態をスイッチＯＦＦ状態として利用するスイッチングデバイスとした
    　ことを特徴とする可変抵抗デバイス。     In the variable resistance device according to claim 4,
    By applying a voltage or current between the first electrode and the second electrode within a range not exceeding the turn-on voltage and the turn-off voltage, the high conduction state is used as the switch ON state, and the low conduction state is used. A variable resistance device characterized by being a switching device that uses the switch off state.
  8. 　請求項１～３のいずれか一項に記載の可変抵抗デバイスにおいて、
    　前記第１電極を、チャネル経路を形成可能な材料とし、
    　前記第１電極の前記チャネル経路を制御するゲート機構を備え、
    　前記ゲート機構を介して前記チャネル経路を開方向に制御して、前記第１電極の前記チャネル経路、前記有機膜の積層方向、および前記第２電極にターンオン電圧を印加することにより、トランジスタとした
    　ことを特徴とする可変抵抗デバイス。     The variable resistance device according to any one of claims 1 to 3.
    The first electrode is used as a material capable of forming a channel path.
    A gate mechanism for controlling the channel path of the first electrode is provided.
    The channel path is controlled in the open direction via the gate mechanism, and a turn-on voltage is applied to the channel path of the first electrode, the stacking direction of the organic film, and the second electrode to form a transistor. A variable resistance device characterized by that.
  9. 　請求項１～８のいずれか一項に記載の可変抵抗デバイスを製造する方法において、
    　前記第１電極、前記有機膜、および前記第２電極を形成する形成工程を備え、
    　前記有機膜の形成工程において、前記有機膜の形成温度により、前記異方性の配向をコントロールする
    　ことを特徴とする可変抵抗デバイスの製造方法。     In the method for manufacturing a variable resistance device according to any one of claims 1 to 8.
    A forming step for forming the first electrode, the organic film, and the second electrode is provided.
    A method for manufacturing a variable resistance device, which comprises controlling the anisotropic orientation by the formation temperature of the organic film in the process of forming the organic film.
  10. 　請求項９に記載の可変抵抗デバイスの製造方法において、
    　前記有機膜の形成工程において、前記有機膜の膜厚設定により、
    　前記可変抵抗デバイスがターンオンするターンオン電圧、および前記可変抵抗デバイスがターンオフするターンオフ電圧をコントロールする
    　ことを特徴とする可変抵抗デバイスの製造方法。     In the method for manufacturing a variable resistance device according to claim 9.
    In the process of forming the organic film, by setting the film thickness of the organic film,
    A method for manufacturing a variable resistance device, which comprises controlling a turn-on voltage at which the variable resistance device turns on and a turn-off voltage at which the variable resistance device turns off.
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