JPS6295882A - Electrical memory equipment - Google Patents

Abstract

PURPOSE:To realize an easily manufacturable electrical memory equipment by forming a film which contains an organic charge mobile complex compound between electrodes facing each other. CONSTITUTION:After the first electrode 11 is formed by depositing copper on a glass substrate, the electrode is dipped in an acetonitrile solution of TCNQ (tetracyanoquinodimethane complex) and a film 13 made of a complex of TCNQ and copper is formed on the surface of the copper electrode 11. Then, the second electrode 12 is formed by applying an aluminum paste on the film 13. In an electric element obtained in this way, if the electric potential of the first electrode 11 is made higher than that of the second electrode 12, the film 13 is maintained a high resistance state to threshold intensity of electric field and is suddenly switched to a low resistance state at higher intensity. In such a state, no change at the normal temperature and the element can be used for a memory equipment. Further, in order to return to the original high resistance state, heating and slow cooling or applying a current bias is required.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to rewritable electrical storage devices for logic electronic circuits.

[Conventional technology]

Conventionally, various electrical storage devices have been put into practical use. Among them, EP is an electrical storage device that retains written information even during power outage and is rewritable.
ROM is widely used.

A typical configuration example of this EPROM is shown in FIG. In this EPROM, when writing "1", a high negative voltage is applied to the train 41 to generate an avalanche between it and the gate 43. High-energy electrons generated by this avalanche jump into the floating gate 43. This is charged negatively, but this charge is transferred to the insulating layer (Si
02) Because it is surrounded by gate 46, even if the voltage of train 41 is removed, it will remain at gate 43, and as a result
1 and source 42 becomes electrically conductive. Readout is performed by checking whether current can flow through the element (when it is “1”) or not (when it is “○
°゛) is detected. To erase information, irradiate it with ultraviolet light.

[Problem that the invention attempts to solve]

However, such conventional electrical storage devices require so-called semiconductor manufacturing techniques, that is, expensive and complicated equipment and advanced technology, and cannot be easily manufactured with simple equipment, for example, by those skilled in the art. It was not something that could be easily produced even by general electronics enthusiasts.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a rewritable electrical storage device having a structure that can be easily manufactured with simple operations.

[Means for solving problems]

The above object can be achieved by the following invention.

The present invention provides a series junction constructed by connecting in series an electric element having a film containing an organic charge transfer complex compound formed between opposing electrodes and an electric resistor; , an electrical means for selectively applying a voltage in accordance with a logic signal to be recorded to change the resistance value of the electric element; and an electrical means for extracting the change in the resistance value of the electric element as a logic signal. An electrical memory device comprising: one or both of the electrodes being formed by applying a material capable of forming the electrode to a predetermined portion.

That is, the present invention aims to provide a rewritable electrical memory device M having a structure that can be easily produced by effectively utilizing the voltage-current characteristics of a thin film containing an organic charge transfer complex compound. This made it possible.

As shown in FIG. 1, the electric element incorporated into the device of the present invention is an organic charge transfer device composed of two opposing electrodes 11 and 12, and an electron donor and an electron acceptor sandwiched between these electrodes. It basically has a thin film 13 containing a complex (hereinafter abbreviated as a complex-containing thin film).

As the complex-containing thin film 13 that can constitute an electric element incorporated into the device of the present invention, as an electron donor,
One or more selected from the group consisting of inorganic cations containing silver and/or copper: As an electron acceptor, general formula: (
CN)2C(・Z・)C(CN)2 (Here F, G,
H and H are each independently hydrogen, a halogen atom, an aliphatic hydrocarbon group having 1 to 3 carbon atoms, an ether group having 1 to 3 carbon atoms, or a cyano group. For example, a thin film containing a complex compound composed of one or more kinds of Cu-
TCNQ (copper-tetracyanoquinodimethane complex), C
u-TNAP (copper-II, II, 12.12-tetracyano-2,6-nafdoquinodimethane complex), Cu-TC
NQF4 (copper-2,3,5,6-titrafluoro7.
7.8.8-tetracyanoquinodimethane complex), A9
Suitable examples include thin films containing TCNQ, A9TNAP, A9TNQF4, and the like.

This complex-containing thin film 13 may contain, for example, one or more of the above-mentioned organic charge transfer complexes, if it itself has film-forming properties (in this case, if it does not have film-forming properties itself, it may contain one or more organic charge transfer complexes). Electrodes can be formed using various film-forming methods depending on the organic charge transfer complex used, such as mixing with a substance that acts as a binder and dissolving or dispersing it in a solvent as necessary. 11 (or electrode 12).

Alternatively, the electrode 11 containing copper and/or silver may be brought into contact with a compound capable of forming an electron acceptor of the organic charge transfer complex to cause a complex reaction, and the electrode 11 containing copper and/or silver may be brought into contact with the surface of the electrode 11 containing copper and/or silver. It can also be formed by forming a film 13 containing an organic charge transfer complex containing copper and/or silver on the surface.

This complex-containing thin film 13 has voltage-current characteristics suitable for constructing an electrical element as shown in FIG. 1 which is incorporated into the rewritable electrical storage device of the present invention.

That is, in an element having the configuration shown in FIG. 1, the electrode 11 as the positive electrode is made of copper, and the electrode 12 as the negative electrode
To explain the case where 13 is formed of aluminum and the above-mentioned complex-containing thin film 13 is used, as the potential of the copper electrode 11 is increased with respect to the aluminum electrode 12, as shown in FIG. , the complex-containing thin film 13 maintains a high resistance state up to a critical electric field strength Ec of 103 V/mm to 106 V/m, although it varies depending on the film thickness of the layer.
With a critical voltage strength Ec of about m, the resistance value is about 103Ω/m
From a high resistance state of m2 to about 109Ω/mm2 (off resistance value: Rou) to about 10Ω/mm2 to about 103Ω/mm2
Switching to a low resistance state of (on-resistance value: days.).

Moreover, this low resistance state has a memory property, and even if it is left at room temperature for several hours or more, an increase in resistance value of about 10X is observed.

In addition, the complex-containing film 1 changes from this low resistance state to a high resistance state.
3, the complex-containing thin film 13 is heated, for example, at 200'C.
Alternatively, a current pulse may be applied to the complex-containing thin film 13.

Note that the electrodes 11 and 12 can be formed using a material appropriately selected from those commonly used as electrode forming materials such as copper, silver, and aluminum, and by various known methods depending on the material used. However, in the device incorporated into the device of the present invention, at least one electrode is placed on a suitable substrate such as glass, or on a predetermined portion of a complex-containing thin film already formed on one electrode. It is formed by applying a forming material. Note that, as described above, when forming a film containing an organic charge transfer complex containing copper and/or silver by causing a complex formation reaction on the surface of the electrode 11, the electrode 11 may be made of copper and/or silver. Or formed by containing silver.

The method of applying the above-mentioned electrode forming material of the present invention can be applied to a normal step-one printing technique as an electrode forming method, and thus simplifies the process in producing the electrical storage device of the present invention. EMBODIMENT OF THE INVENTION An electric element that can be used in the present invention over a large area (Example) An example of the present invention will be described below with reference to the drawings.

FIG. 3 shows an example of the configuration of the rewritable electrical storage device of the present invention.

In this device, a film 33 (thickness, 5 - ), an electric element C■ formed with an electric resistor R,
a series junction 34 connected in series with the series junction 34;
A portion 35 (encircled by a dashed line) constituting a means for selectively applying a high voltage to both ends of the electric element CI according to a logic signal to be recorded to change the resistance value of the electric element CI; A portion 36 (the portion surrounded by a solid line) constitutes an electrical means for extracting a change in the resistance value of CI as a logic signal. Note that the resistance R1
is the resistance value and the resistance value Ro of the Cu-TCNQ film 33.
The intermediary between N and Ro14 is RON<: RHCRon
In this device, the Cu-TCNQ film 33 of the electric element CI has a film thickness 3 of 5μ, and Ro is 380Ω in an electrode area of 1mm2.
Since H was 860Ω, R1 was 5.1Ω.

In this device, in order to record the logical "L" state, first the write signal is set to the "H" state and the switching elements SL and SW2 are turned on. When the read signal is set to “H” state in this state, SW3 is turned on,
A high voltage VB is applied to the Cu-TCNQ film 33 with a thickness of 3. As mentioned above, if the resistance value of R1 is 5. IKΩ, and since the Cu-TCNQ film 33 film amount 3 is in a high resistance state, most of the potential of the high voltage V8 is applied to the Cu-TCNQ film 3
3 film amount 3 ru. At this time, if a high voltage v8 of a level that can be applied to the 'critical electric field strength Ec@Cu-TCNQ film 33 shown in FIG.
By switching from the Q film 33 film amount 3 resistance state to the low resistance state, this state is memorized and the recording operation is completed.

In this example, a constant voltage of 20V was used as the high voltage v8.

On the other hand, to read the recorded logic state, maintain the write signal in the "L" state and set the read signal to "H".
SW3 is turned on, a constant voltage VC is applied to the series junction 34 through the diode DI, and the Cu-TCN
Q film 33 film amount 3 states, that is, the logical value “
Depending on whether the Cu-TCNQ film 33 film thickness 3 is in the low state or not, the potential at point A becomes high.
” and “Shi” again. This potential information is sent to SW4 and R2,
It is read by an inverter circuit consisting of R3 and R4.

In this example, the writing section 37 (encircled by the dotted line) consisting of SW+ and SW2 and the reading section 36 including the element CI are integrated, but they are each separated into separate parts. It is also possible to have a configuration in which these devices are connected using means such as a connector only during writing. In such a case, the diode DI is unnecessary.

Furthermore, by connecting a constant voltage power supply directly to point B and selectively applying a read signal, it is possible to change the resistance state of the element CI and record it. With such a configuration, it is possible to simplify the device.

The device used in the configuration example of the present invention shown in FIG. 1 was manufactured as follows.

First, a substrate made of glass (26x 76x 1mm
) on one side of the first
An electrode was formed. In addition, to form this copper electrode, for example, a glass epoxy etching substrate (manufactured by Sanhaseto Corporation) is used.
etc. may also be used.

Next, TCNQ powder (manufactured by Osaka Organic Chemical Co., Ltd.) purified by sublimation was dissolved in acetonitrile purified by distillation until saturated. When a substrate on which copper electrodes have already been formed is immersed in the acetonitrile saturated solution of TCNQ prepared in this manner, a complex of ICNG and copper is formed on the surface of the copper electrodes, and after continued immersion at 25°C for 5 minutes, 5 on the copper electrode
A Cu-TCNQ complex film having the thickness of a scale was formed. Note that the temperature of the solution during immersion is such that Cu is fine and has good performance.
- To form a TCNQ complex film (usually 20~
The temperature may be 30°C, and the formed Cu-TCNΩ
The thickness of the complex film affects the critical electric field strength of the layer, so the thickness of the layer should be controlled to the desired thickness by adjusting the dipping time depending on the design of the element to be formed. Good.

Finally, on the Cu-TCNQ complex film formed on the surface of the copper electrode, apply aluminum paste (manufactured by Engel Hard Industries) while thinly stretching it with a glass rod, etc. to form a negative electrode with a film thickness of 2 to 5 scales. An aluminum electrode was formed, and the formation of an electric element consisting of a Cu-TCNQ complex film sandwiched between a copper electrode and an aluminum electrode was completed. In addition, as another method for forming the electrode, good results were obtained when the electrode pattern was applied using a screen printer for thick film printing.

Note that when forming electrodes using aluminum paste, if the electrode to be formed is too large or too long, resulting in a voltage drop, it should be noted that if the electrode is too large or too long, it may cause a voltage drop. Copper wires of about I6rnm are appropriately placed, and furthermore, aluminum paste or a paste commonly used in other electrical devices can be applied thereto to prevent voltage drop.

[Effects of the Invention] According to the present invention as described above, an electric element having a thin film containing an organic charge transfer complex compound included in the device of the present invention can be manufactured using a conventional semiconductor. The present invention provides a rewritable electrical memory that is easy to fabricate not only for those skilled in the art but also for general electronics enthusiasts. It became possible to provide the equipment.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of an electric element incorporated into the device of the present invention, and FIG. 2 is a graph showing the voltage-current characteristics of a thin film containing an organic charge transfer complex compound used in the device of the present invention.
FIG. 3 is a schematic diagram showing an example of the configuration of the device of the present invention, and FIG.
The figure is a schematic diagram of a conventional rewritable electrical storage device. 11.12.3I, 32: Electrode 13.33/Complex-containing thin film 34: M-row junction 35: Portion constituting means for changing the resistance value of electric element CI 36: Change in resistance value of electric element CI Part 37 constituting an electrical means for extracting as a logic signal: IF input section 41 Nidrain 42: Source
43: Gate 44: A1 layer 45
・. One substrate 46: Insulating layer 47: P+ layer C
I: Electrical element Or: Diode IR2, R4: Resistor SW+, SW2, SW3, SW4: Switch V8, VC: Power supply

Claims (1)

[Claims] 1) A series junction configured by connecting in series an electric element in which a film containing an organic charge transfer complex compound is formed between opposing electrodes and an electric resistor: the series junction. electrical means for selectively applying a voltage across the terminal according to the logic signal to be recorded to change the resistance value of the electric element;
and an electrical means for extracting a change in the resistance value of the electric element as a logic signal, and one or both of the electrodes is formed by applying a material capable of forming the electrode to a predetermined portion. An electrical storage device characterized in that it is 2) means for changing the resistance value of the electric element;
2. The electrical storage device according to claim 1, wherein the electrical means for extracting a change in the resistance value of the electrical element as a logic signal can be separated from the electrical means. 3) The film containing the organic charge transfer complex compound,
As an electron donor, one or more selected from the group consisting of inorganic cations containing silver and/or copper; and as an electron acceptor, the following general formula: (CN)_2C(=Z=)C(CN
)_2 [Here, (=Z=) is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and A, B, D, E in these structural formulas ,F,G,
H and I each independently represent hydrogen, a halogen atom, a C1-3 aliphatic hydrocarbon group, a C1-3 ether group, or a cyano group. The electrical storage device according to claim 1 or 2, which is a film comprising an organic charge transfer complex compound composed of one or more selected from the group consisting of compounds represented by the following.