JPS62201968A - Organic memory element - Google Patents

Abstract

PURPOSE:To provide an org. memory element which has an excellent memory density and allows quick access, containing an electrolyte soln. and electrodes modified by a metal complex (contg. a high-molecular material) wherein a photoisomerizable org. material is used as a ligand molecule. CONSTITUTION:An electrode, an opposing electrode, a reference electrode and an electrolytic soln. are modified by using a metal complex wherein at least one photoisomerizable org. material is used as a ligand molecule (e.g., compds. of formulas I and II, wherein azpy is a group of formula III and bpy is a group of formula IV) or a high-molecular compd. (e.g., polyvinylpyridine) contg. said metal complex. A memory element is formed by using the resulting modified electrode, opposing electrode, reference electrode and electrolytic soln. When the memory element is irradiated with light, the ligand molecules of the org. materials of formulas III, IV, etc., are reversibly photoisomerized and changes in the coordination number of metals are accelerated to thereby change the redox potential of the org. metal complex. Thus, the input and output of information can be made in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The dud f3J4 relates to high speed, high density organic memory elements.

[Conventional technology]

Conventionally, memory elements are processed using silicon-based and all-resist technology, ion implantation technology, etching technology, vapor deposition technology, etc.
It has been manufactured by forming a microscopic device.In recent years, the miniaturization has progressed even further, and devices with a minimum pattern size of 1 μm or less are being developed. As the technology becomes more sophisticated, processing methods become more complex, leading to the adoption of new processing methods, an increase in the number of steps, and an increase in manufacturing costs.

Furthermore, in devices using silicon as a substrate, there are essentially unsolvable problems such as an increase in resistance due to thinning of the wires, problems with heat treatment, and the occurrence of nonlinear phenomena and quantum effects. It is believed that there are limits to

As a technology to break through this limit, research is underway into organic material gold functional elements. In other words, in inorganic materials, the function as an electronic device is expressed only when thousands or tens of thousands of atoms come together, whereas with organic materials, so-called molecular devices in which each molecule functions can be expected. be.

For example, Friedrich and I.-Ler of IBM et al. have shown that when a fully monochromatic laser beam is irradiated onto an absorber that has a nonuniform spread of organic molecules in a solid medium, the absorption spectrum exhibits a sharp (narrow broadening). We have discovered the so-called photochemical hole burning (PHB) phenomenon, in which holes are opened, and have reported that by spectroscopically detecting this phenomenon, it can be used as a wavelength multiplexing ultra-high density storage element (A.

R. Gutuierrez, J.
, Friedrich, D.
Haarer and H. Wolfram (
WoMrum), IBM Journal Op Research and Development (M Res,
Dsvelop, ) Volume 26, Page 198 (198
2 years)]. However, PHB elements have problems that make them unsuitable for large-capacity storage, such as they operate only at extremely low temperatures and the information evaporates when the temperature rises, and the mechanisms for soaking and reading are complex and sophisticated.

In addition, Carter et al. at the U.S. Naval Research Laboratory have demonstrated the possibility of using molecules as switching devices or memory devices by exploiting the fact that molecules reversibly change their structure to blonde in response to external stimuli. [New York City, Marael Dekker Co., Ltd.]
Published in 1982, F, L.

Carter, Molecular E'1
electro-niODevices) ). Furthermore, we proposed the idea of changing the overlap of electron clouds in a one-dimensional organic @-body compound with a well-type potential by an external stimulus, and making the conductive gold switch stronger. (, T. H., Moa
lear) and T, M, Wellung (W
ehrung), 1981 Japanese Society of Applied Physics Technical Conference Abstracts (IEEE-Japan, Soc,
Appl Phys, Meeting.

Digest of Tech, Papers, )
82 pages]. However, these molecular devices t-real
In order to achieve this, molecular synthesis technology, molecular arrangement f1L technology,
Regarding interfaces with molecules, etc., it is not clear. On the other hand, Haas et al. have proposed using organometallic complexes as memory elements by taking advantage of the fact that their coordination state changes when irradiated. Proposing [o, Haas (Ba
as) M, Kr1ans and J, (), Vos, Journal of
The American Chemical Society (J, Am,
Chem, Boa, ), Volume 103, No. 131
8 pages (1981)]. However, a considerable amount of light exposure is required to detach the organic compound coordinated with the metal, and once the coordination molecule is detached, it cannot be coordinated again, so it can only be used as a fixed memory. .

[Problem that the invention seeks to solve]

The present invention has been made to eliminate these drawbacks, and its purpose is to provide a replaceable memory element that utilizes reversible structural changes at the molecular level of organic materials.

[Means to solve the problem]

To summarize the present invention, the present invention relates to a V-mechanical memory element, which is a photoisomerizable organic material having at least one gold-M complex as a gold coordination molecule, or a polymer compound containing the gold-M complex. Qualified electrodes, facing! Electrode, reference electrode, and electrolyte solution characterized by containing gold 0 In other words, a certain electrode is selectively irradiated with light (-1 The structure of the coordination molecules in the organometallic complex on its surface changes completely, and the coordination of the metal By changing the order, the redox potential of the organometallic complex on the irradiated electrode changes compared to before irradiation, which is used as a memory element.In the present invention, the photoisomerism of the coordination molecule is Since desorption promotes the activation of the coordination structure T, it is much faster than desorption by light irradiation, and redox potential can be measured in an extremely short time, making it possible to input and output information in a short time and with ease. Historically, since photoisomerization is a reversible reaction, it is possible to return the complex to the state of the coordination number by causing a reverse reaction, and it is possible to replace the information. In the present invention, by using a molecular association that performs reversible isomerization, it has been possible to realize a recording element that is capable of high-speed processing and that is also replaceable.

The organic memory element of the present invention contains 1! Preferably, the electrodes are a complete array of a plurality of electrodes that are insulated from each other.

The organic material that is the coordination molecule may be any material as long as it can be photoisomerized to change the coordination number of the complex, but preferably has the following general formula 1slr, It: (where R and R are
Preferred materials are hydrogen, halogen, alkyl groups, alkoxyl groups, hydroxyl groups, aromatic groups, and derivatives thereof (which may be the same or different). Halogens of formula Is n,i include fluorine, chlorine, bromine, and iodine. Examples of the alkyl group include methyl group, ethyl group, globyl group, butyl group, and derivatives thereof. Examples of the alkoxyl group include methoxy, ethoxy, propoxy, butoxy, and derivatives thereof. Examples of the aromatic group include a phenyl group, a naphthyl Δ group, an anthracenyl group, and the like. By changing these substitution funds, organometallic complexes are mainly formed on the electrode.
Compatibility with solvents during formation, adhesion with electrodes, and stability during use can all be optimized.

In addition, elements that form complexes include iron, ruthenium,
Examples include osmium, cobalt, chromium, copper, manganese, nickel, lead, platinum, and soot.

Examples of coordination molecules that cause photoisomerization include the following.

Examples of polymer compounds containing metal complexes include mixtures of polymers such as NafiOn (manufactured by DuPont), polyvinylpyridine, and sulfonated polystyrene with metal complexes, or monomers themselves containing metal complexes. or a comonomer of the monomer with vinylpyridine, sulfonated styrene, etc.

Examples of coordination molecules caused by electrolytic heavy alloys include CH2=
Examples include CH divinylporphyrin.

Examples of coordination molecules include (C6H5)! P% (p-CHsCsHa)sPs
(Cabs)sAθ, (C8H5)38b.

(C4Hs)! P% (C6H5)zPcH3, (C
sHs)zAacHzA8(CaHs)z, (CsHs
)zPcmiCP(C5Hs)z, (C5Hs)z
P (CHz) nP(C5Hs)z (n=1-
9), etc.

Further, examples of the counter ion of the metal complex include barchlorate ion, 67 fluoride phosphorus ion, tetrafluoride fluoride ion, and the like.

The plurality of electrode arrays used in the present invention can be easily produced, for example, by the following method, but other methods may be used as long as a pattern with similar conductivity can be formed on the substrate. That is, on an insulating substrate such as a quartz substrate or a silicon-based substrate with an oxidized surface, a wiring pattern of platinum, gold, aluminum, etc. is created using gold phosphorography technology, and an electrode of platinum, etc. is formed at the electrode connection part of each wiring pattern. and connect each wire. After forming an insulating layer of silicon nitride or the like thereon, all through holes are formed on the electrode, and a plurality of electrodes are formed on the substrate.

For example, the following method can be used to modify the organic material that undergoes total photoisomerization on the surface of each electrode with a metal complex having at least one coordinating molecule or a polymer compound containing the metal complex. That is, after covering the entire surface of the substrate where the electrodes are located with the organic metal material, a resist or the like is used to coat the organic metal material only on the electrodes. You can process it so that it remains 0 or an organic material that photoisomerizes and an organic material that can be electrolytically polymerized At least one metal complex awaits each as a total coordination molecule on each electrode! Each electrode can also be modified by depolymerization.

The oxidation-reduction potential is determined by applying the memory element to a bath medium containing an electrolyte.
This is carried out by inserting a counter electrode such as platinum or a reference electrode such as a saturated calomel electrode, and measuring the total potential of the oxidation or reduction reaction of the metal complex on each electrode using a potentiostat or the like.

Alternatively, the following method is also possible. In other words, if the modified organometallic complex has a higher redox potential (oxidation reaction) than the electrode, the redox potential is lower than that oxidation potential (reduction reaction).
In this case, a metal complex having an oxidation or reduction potential higher than the reduction potential of gold is added in advance to the electrolyte solution. The isomerization state of the metal complex on each electrode can be detected by reading the potential of the electrode and the presence or absence of current when the potential is set to an intermediate potential between the oxidation or reduction potentials before and after photoisomerization of the metal complex.

As the electrolyte used in these potential measurements, a salt consisting of a cation such as an alkali metal ion or a quaternary alkyl ammonium salt and an anion such as a halogen ion, a sulfate ion, or a perchlorate ion can be used. Alternatives include tetraethylammonium perchlorate, tetran-butylammonium perchlorate, tetraethylammonium tetrafluoroboron,
Examples include tetra n-butylammonium and tetrafluoroboron. The solvent may be any solvent as long as it has enough dielectric constant to dissolve the electrolyte and completely dissociate the dissolved electrolyte, such as water, acetic anhydride, methanol, tetrahydrofuran, and propylene. Carbonate, nitromethane, acetonitrile, dimethylformamide, dimethyl sulfoxide, hexamethylphosphotriamide, and the like.

On the other hand, as a light source for writing information or changing the name, any light source that causes photoisomerization of the organic material of the coordination molecule may be used, such as an ultra-high pressure mercury lamp, a xenon lamp, an argon laser, or a dye laser. Examples include. In addition, it can be independently controlled to change back to the original wavelength.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to all examples,
The present invention is limited to these T-sparing methods.The solution was dissolved in 9.4 liters of pyridine and 50 grams of gold dimethylformamide, and 85 grams of lithium chloride was added thereto, followed by refluxing for 8 hours.

Thereafter, 250 °C of acetone was added and the mixture was left at 0°C for 24 hours. After filtration with the obtained crystalline gold filter, it was washed with water and diethyl ether. Next, the crystals 2.62 and 5,
5'-Azopyridine 9F was dissolved in a mixture of total water and ethanol (1=1) #500, and after blowing nitrogen gas into it for 20 minutes, it was refluxed in a nitrogen stream for 5 hours. Then, an excess of lithium perchlorate was added to obtain 1.8% of reddish-orange crystals.

Production Example 2 Ruthenium trichloride trihydrate (7.8 t) was dissolved in 11 ri of 5,3-azopyridine and 50 - of dimethylformamide, 85"vffi of lithium chloride was added thereto, and the mixture was refluxed for 8118 min. Then, 250 ml of acetone was added and It was left to stand for 24 hours at ℃.The obtained crystals were filtered with water,
Washed with diethyl ether. Next, 2.3t of the crystals and 9tf of 3,3'-azopyridine water:ethanol=1=1
300m7 of mixed solvent! After blowing in nitrogen gas for a total of 20 minutes, the mixture was refluxed in a nitrogen stream for 55 hours. Then, add lithium perchlorate in total excess to give red-orange crystals 1.
9 f'! l-obtained.

Production Example 3 Synthesis was carried out in the same manner as in Production Example 1, except that osmium trichloride was used instead of ruthenium trichloride trihydrate, and red-orange crystals were obtained.

Production Example 4 When synthesis was carried out in the same manner as in Production Example 2 using osmium trichloride instead of the trihydrate of ruthenium trichloride, red-orange crystals were obtained.

Production Example 5 Ruthenium trichloride trihydrate (7.8 f) and 3,3-azopyridine (112) were dissolved in dimethylformamide (50), lithium chloride ssW/gold was added thereto, and the mixture was refluxed for 8 hours. Thereafter, 250 ml of acetone was added, and the mixture was left at 0° C. for 24 hours. The obtained crystallization filter was filtered and washed with water and diethyl ether. Next, the crystal 2.3f and N-(4
-pyridyl) sinthiamide 11 whole tone:: ethanol = 1
:Dissolved in 300 g of mixed solvent of 1 and nitrogen gas t-20
After bubbling for a minute, the mixture was refluxed in a nitrogen stream for 55 hours. Then, add to the total excess of lithium perchlorate, red-orange crystals 3
I got ff.

Production Example 6 When the synthesis was carried out in the same manner as in Production Example 5 except that osmium trichloride was used instead of the ruthenium trichloride trihydrate, red-orange crystals were obtained.

Production Example 7 Ruthenium trichloride trihydrate 7.8F, 2.2-bipyridine 9.36t, lithium chloride aJr gold dimethylformamide 50% were dissolved and refluxed for 8 hours. Thereafter, 250 td of ace)yi was added, and the mixture was left at 0° C. for 24 hours. The nine crystals obtained were filtered through a filter and washed with water and diethyl ether. Next, the obtained crystal 2-629
and 1,2-bis(diphenylphosphino)ethylene4.
42" was dissolved in water at 7500 mA, nitrogen gas was blown in for a total of 20 minutes, and then refluxed in a nitrogen stream for 5.5 hours.

Thereafter, an excessive amount of ammonium phosphorus hexafluoride was added to obtain pale yellow crystals 3fi.

Production Example 8 In Production Example 1, 2,2'-bipyridine was replaced with 4-
A metal complex was obtained using vinyl-2,2'-bipyridine. The obtained metal complex 12 and sulfonated styrene 1 ha
- 50 g of azobisbutyronitrile dissolved in 100 g of toluene was added and stirred at 60° C. for 5 hours. The resulting bath was poured into methanol to obtain a reddish color polymer. The copolymerization rate of sulfonated styrene determined by elemental analysis was 63 mol.

Production Example 9 A platinum batt' (i
- Formed in a 2×100 matrix with a diameter of 1 μm and a pitch of 2 μm. Next, each platinum batt and the gold wiring partial were covered with a silicon nitride film, and then the silicon oxide on the platinum was etched to calculate platinum gold. The entire silicon substrate is attached to a substrate with an external connector, and after connecting the connector with the 11L pin gold wire, the platinum portion is removed and covered with an insulating film to form a matrix of platinum! I recorded the sounds.

Examples 1 to 8 Crystals obtained in Production Examples 1 to 4 or 7 (dissolved in a 12% Nafion ethanol solution at a concentration of 0.3 molar,
Electrode substrate 1 obtained by casting in Production Example 9
Each coated with a μm thick metal complex! The entire modified electrode was prepared by etching away the metal complex leaving other parts (Examples 1 to 4 and 7). In addition, Production Examples 5 and 6
The crystalline mixture obtained in Example 9 was dissolved in acetonitrile at a concentration of 0.5 mol.
F, modification to depolymerize! Poles were obtained (Examples 5 and 6). Furthermore, the polymer obtained in Production Example 8 was bathed in all toluene, and the electrode substrate gold obtained in Production Example 9 was coated with the metal complex polymer having a thickness of 1 μm (Example 8).

These i, Q, and IM were immersed in an acetonitrile solution of tetra-n-butylammonium perchlorate, and platinum and gold were faced! Pole, saturated calomel electrode full reference t! As M, the entire redox potential of the complex was measured. Next, the metal complex on the modified electrode was
At the source of the 0W xenon lamp, use a lens to set the aperture to 9 and the wavelength to 400.
After irradiating through the entire filter that absorbs elements below nm,
When the redox potential was measured, the results shown in Table 1 were different.

Example? Taking advantage of the modification in which the coordination molecules obtained in Examples 1 to 8 are photoisomerized, the source of an ultra-high pressure mercury lamp was irradiated through the entire filter that absorbs the principal metal at a wavelength of 400 nm or more, and then Examples 1 to 8 were
When the redox potential was measured in the same manner as in Example 8, the same results as in Table 1 were obtained for all complexes.

〔Effect of the invention〕

As explained above, since the organic memory element according to the present invention is based on the principle of total memory of structural changes when organic molecules are irradiated with a source, the total memory density can be greatly improved.

In addition, since the structural change utilizes all reversible photoisomerization reactions, it is possible to record information.

Furthermore, since all electrochemical methods are used to read information, the fact that 0 or more can be accessed at extremely high speeds has a remarkable effect on increasing the speed and density of memory elements.

Claims (1)

[Claims] 1. An electrode, a counter electrode, a reference electrode, and an electrolyte solution modified with a metal complex having at least one photoisomerizable organic material as a coordination molecule or a polymer compound containing the metal complex. An organic memory element characterized by containing: 2. The organic memory element according to claim 1, wherein the electrode containing the metal complex is an array of a plurality of mutually insulated electrodes. 3. The organic material to be photoisomerized has the following general formula: ▲ Formula,
There are chemical formulas, tables, etc.▼...[I] (In the formula, R_1 and R_2 are selected from the group consisting of hydrogen, halogen, alkyl group, alkoxyl group, hydroxyl group, aromatic group, and derivatives thereof. The organic memory element according to claim 1 or 2, which is a compound represented by the following formula (which may be the same or different from each other). 4. The organic material to be photoisomerized has the following general formula: ▲ Formula,
There are chemical formulas, tables, etc.▼...[II] (In the formula, R_1 and R_2 are selected from the group consisting of hydrogen, halogen, alkyl group, alkoxyl group, hydroxyl group, aromatic group, and derivatives thereof. 3. The organic memory element according to claim 1 or 2, which is a compound represented by the formula (1), which may be the same or different from each other. 5. The organic material to be photoisomerized has the following general formula: ▲ Formula,
There are chemical formulas, tables, etc. ▼...[III] (In the formula, R_1 and R_2 are selected from the group consisting of hydrogen, halogen, alkyl group, alkoxyl group, hydroxyl group, aromatic group, and derivatives thereof. 3. The organic memory element according to claim 1 or 2, which is a compound represented by the formula (1), which may be the same or different from each other. 6. Claim No. 6, wherein the element forming the complex is one or more selected from the group consisting of iron, ruthenium, osmium, cobalt, chromium, copper, manganese, nickel, lead, platinum, and tin. The organic memory element according to item 1.