JPH0936355A - Integrated electronic chemical circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding solid-state devices that utilize the interaction between ions and electrons, conventional semiconductor devices cannot
Iono electron device (Iono
-Providing an electron device). [Structure] Electronic elements and elements utilizing interaction between ions and electrons are integrated on a substrate, and each element is connected by an electron conductor or an ion conductor, and electrons, holes, or ions serve as a signal bearer, An integrated electrochemical circuit characterized in that a carrier of a signal flows organically on the substrate temporally or spatially.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device using electrons, holes or ions as carriers, and more particularly to an integrated electronic circuit having redundancy and plasticity.

[0002]

2. Description of the Related Art Conventionally, a device in which a yttria-stabilized zirconia film, which is a solid electrolyte with oxygen ion conductivity, is formed on the gate insulating film of a field effect transistor made of silicon is disclosed in Journal of Applied Physics, Vol. 63. , 1988, pp. 2431 to 2434 (Journal of
Applied Physics, vol.63, (1988) 2431-2434). This device operates as an oxygen sensor because it generates an electromotive force on the surface of the solid electrolyte depending on the oxygen partial pressure.

[0003]

However, since the device shown in the above prior art detects the electromotive force generated at the gate of the field effect transistor as a change in drain current, the ionic conductivity of the solid electrolyte is not utilized. . Further, since the output of the above-mentioned device only changes depending on the oxygen partial pressure, a plurality of active elements and ion or electron conductors connecting between the elements are not provided, and new functions cannot be expressed. There was a problem that it was possible. The present invention has been made in view of the above circumstances, and an object of the present invention is to solve the above-mentioned problems in the conventional art, and electrons or holes or ions serve as a bearer of signals, and temporally or spatially. An object of the present invention is to provide an iono-electron device (Iono-electron Device) that moves organically and has a function that is difficult to realize by a conventional electronic device.

[0004]

The above object of the present invention is to provide, in an electronic circuit or electronic device formed on a substrate, at least one ion conductor formed on the substrate to convert ions to electrons or electrons to ions. Ion converting
This is achieved by an integrated electrochemical circuit in which an electronic conversion element is arranged so as to connect the electronic circuit or the electronically conductive electrode of the electronic element to the ionic conductor. On the substrate, electronic elements and elements utilizing interaction between ions and electrons are integrated, and the elements are connected by an electron conductor or an ion conductor, and the electrons, holes, or ions serve as a signal bearer on the substrate. It is achieved by a signal carrier flowing organically in time or space.

[0005]

In the integrated electronic chemical circuit according to the present invention,
By the combination of the ionic conductor and the ions flowing in it,
The diffusion rate and mobility of the ions in the ionic conductor can be varied to form a signal carrier that is significantly different from the diffusion rate and mobility of the electrons or holes in conventional semiconductor devices. Further, the device utilizing the ion-electron interaction includes an irreversible process, a drift process, an equilibrium reaction, etc. These can be used alone or in combination, or by combining with a conventional integrated circuit, It is possible to construct an integrated electrochemical circuit having a complicated function that has never existed before.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an integrated electrochemical circuit showing a first embodiment of the present invention. In the figure, 1 is a silicon substrate, and 2 and 3 are source regions and drain regions formed on the silicon substrate 1. Further, 4 is an insulating film, and the above-mentioned substrate surface is covered with the insulating film 4,
A field effect transistor is formed. The insulating film 4
An ionic conductor 5 is laminated on the ionic conductor 5, and a gate electrode 6 is formed between the source region 2 and the drain region 3 on the ionic conductor 5. A metal electrode 7 is formed on the other surface portion of the insulating film 4, the ion conductor is laminated thereon, and a metal electrode 8 is further formed on the ion conductor 5.

As the above-mentioned ionic conductor 5, for example,
Using a solid electrolyte exhibiting oxygen ion conductivity, a metal electrode 7
Platinum having a catalytic action of oxygen dissociation is used for and 8. The metal electrode 8 is made porous in order to enhance the efficiency of oxygen dissociation. When an appropriate voltage is applied to the metal electrodes 7 and 8, oxygen dissociation equilibrium is established in the metal electrode 8 according to the oxygen partial pressure in the atmosphere, and the oxygen ion concentration in the solid electrolyte 5 changes. Oxygen ions generated at the electrode 8 diffuse in the solid electrolyte 5 and reach the gate portion of the field effect transistor to modulate the channel current. Oxygen ions in the solid electrolyte 5 are not only diffused purely, but also the gate electrode 6 and the electrode 7.
Or it moves by the potential gradient due to the potential difference between 8.

Therefore, according to the above embodiment, by controlling the oxygen partial pressure and the voltage applied to the electrodes 7 and 8, the switching speed of the field effect transistor can be controlled, and the same structure, The materials can realize devices with different switching speeds. FIG.
It is sectional drawing of the integrated electrochemical circuit which shows the 2nd Example of this invention. In this embodiment, similarly to the first embodiment, the source region 2 and the drain region 3 are formed on the silicon substrate 1 and the surface is covered with the insulating film 4 to form the field effect transistor structure. Further, the ion conductor 5 is laminated on the insulating film 4 and connected to the drain region 3 via the metal electrode 9. A gate electrode 6 is formed on the insulating film 4 between the source region 2 and the drain region 3.

A metal electrode 8 is formed on the surface of the ionic conductor 5. Here, for example, the first embodiment
Similar to (see FIG. 1), a solid electrolyte having oxygen ion conductivity is used as the ion conductor 5, and platinum having a catalytic action of oxygen dissociation is used for the metal electrodes 8 and 9. Metal electrode 8
Is made porous to increase the efficiency of oxygen dissociation. When a voltage is applied between the electrodes 8 and 9, electrons having information are converted into ions at the electrode 8, and the ions having information diffuse into the solid electrolyte 5 and reach the electrode 9. That is, the information carrier is converted from electrons to ions, and the solid electrolyte acts as an information passage.

At the electrode 9, ions are converted into electrons, and electrons having information are transmitted through the semiconductor. Therefore, according to the above-described embodiment, by selecting the solid electrolyte material, it becomes possible to make the moving speed of oxygen ions in the solid electrolyte slower than the moving speed of electrons in silicon. The delay element can be realized. FIG. 3 is a sectional view of an integrated electrochemical circuit showing a third embodiment of the present invention. In this embodiment, the insulating film 4 is formed on the silicon substrate 1 having high electrical conductivity, the ion conductor 5 is laminated on the insulating film 4, and the electrodes 10 and 11 are formed on the surface of the ion conductor. Is formed.

A metal electrode 12 is formed on the back surface of the silicon substrate 1 so as to make ohmic contact. Since the silicon substrate 1 has high electrical conductivity, the silicon substrate itself can be used as the gate electrode. The electrodes 10 and 11 can be considered as a source and a drain, and form a transistor structure with the silicon substrate 1, that is, the gate electrode 12. Under normal conditions, the oxygen partial pressure in the atmosphere can be considered constant. Then the sauce,
When a voltage is applied between the drains, electron-ion conversion or ion-electron conversion occurs at each electrode, and oxygen ions flow in the solid electrolyte.

At this time, when a voltage is applied between the electrode 10 or 11 and the gate electrode 12, the ions in the solid electrolyte are attracted or repelled by the gate electrode due to the polarity of the voltage,
The moving speed of the ions changes. This changes the current flowing between the electrodes 10 and 11, that is, the drain current. Therefore, according to the above-described embodiment, the current based on ionic conduction can be controlled by the gate electrode, and the ionic conductor transistor element can be realized. Combining a plurality of the above-described first to third embodiments,
Alternatively, by using this in combination with a conventional electronic element, it is possible to realize a function that cannot be realized by a conventional integrated circuit made of only a semiconductor.

FIG. 4 is a sectional view of an integrated electrochemical circuit showing a fourth embodiment of the present invention. In this embodiment,
A source region 2 and a drain region 3 are formed on a silicon substrate 1 and the surface thereof is covered with an insulating film 4 to form a field effect transistor structure. As the material of the insulating film 4, a two-layer insulating film in which silicon nitride, aluminum oxide, and tantalum oxide are laminated on silicon oxide is desirable. A second substrate 14 is provided on the insulating film 4 via a spacer 13. The electrode 11 is provided on the insulating film 4 at a portion other than the gate, and the electrode 10 is provided on the gate on the side facing the insulating film 4 on the second substrate 14. A gap between the silicon substrate and the second substrate is filled with a liquid ion conductor 15 such as an aqueous solution in which a salt is dissolved.

The above-mentioned silicon nitride, aluminum oxide,
Tantalum oxide acts as a hydrogen ion-sensitive film and generates an electromotive force according to the hydrogen ion concentration (pH) in the liquid electrolyte. This equivalently changes the gate voltage and modulates the drain current. When a voltage is applied to the electrodes 10 and 11, electrolysis of water occurs, hydrogen ions are generated at one electrode, and hydroxide ions are generated at the other electrode, and the pH in the vicinity of the electrodes changes. Since the electrode 10 is formed on the pH sensitive film of the field effect transistor, the pH change occurring near the electrode 10 is detected by the field effect transistor, and the output is changed accordingly. The production efficiency of hydrogen or hydroxide ions depends on the magnitude of the voltage applied to the electrodes 10 and 11, and the output changes depending on the diffusion rate of the ions produced at the electrodes.

Since the moving speed of hydrogen ions and hydroxide ions in the electrolytic solution is slower than the moving speed of electrons in silicon, a delay element can be realized. The output of the field effect transistor exhibits various characteristics by changing the electrolyte material, the magnitude of the applied voltage, the geometrical shape, etc., so that the Iono-electron Device having various delay times can be realized. FIG. 5 is a sectional view of an integrated electrochemical circuit showing a fifth embodiment of the present invention. In this embodiment,
The arrangement of the silicon substrate 1, the second substrate 14 and the electrode 11 is the same as in the case of the fourth embodiment (see FIG. 4), except that the electrode 10 is provided facing the electrode 11. Furthermore, electrodes 16 and 17 are provided outside the flow path connecting the electrodes 10 and 11 and the field effect transistor.

When a voltage is applied between the electrodes 10 and 11,
Generates hydrogen ions and hydroxide ions in the electrolyte. Electrode 1
When a voltage is applied between 6 and 17, the generated hydrogen ions and hydroxide ions move in opposite directions depending on the polarity of the voltage. Since the gate of the field effect transistor is formed in the middle of the flow path, the pH change accompanying the movement is detected and the output is changed. The electrodes 16 and 17 can be used as a driving force for moving ions. Since the output voltage of the field effect transistor depends on the amount of generated hydrogen ions and hydroxide ions and the magnitude of the voltage applied to the electrodes 16 and 17, various delay times are obtained according to the above embodiment. It is possible to realize a delay element having the same.

FIG. 6 is a sectional view of an integrated electrochemical circuit showing a sixth embodiment of the present invention. Also in this embodiment,
The arrangement of the silicon substrate 1 and the second substrate 14 is the same as that of the fourth embodiment (see FIG. 4), but two sets of electrodes 18, 1 are arranged.
The difference is that 9 and 20, 21 are arranged at target positions with respect to the field effect transistor. When a voltage is applied to the electrodes 18 and 19, hydrogen and hydroxide ions are generated at each electrode. Similarly, when a voltage is applied to the electrodes 20 and 21, hydrogen and hydroxide ions are generated at each electrode. Depending on the polarity and magnitude of the voltage applied to the electrodes 18, 19 and 20, 21, a hydrogen ion excess state or a hydroxide ion excess state or a neutral state can be created in the gate of the field effect transistor, and the electric field is accordingly changed. It is possible to change the output of the effect transistor.

Therefore, according to the above embodiment, the electrodes 18,
A logic circuit having 19 as an input 1 and electrodes 20 and 21 as an input 2 can be configured, and the output of the field effect transistor can be configured to take three states of 1, 0 and -1, for example. it can. FIG. 7 shows a seventh embodiment of the present invention. 7 (a) is a sectional view of the integrated electrochemical circuit according to this embodiment, and FIG. 7 (b) is a plan view thereof. In the sixth embodiment, the number of electrodes provided in the ion conductor 15 is increased, and the plurality of electrodes 23 are arranged on the glass substrate equidistant from the gate portion 22 of the field effect transistor. The local part consisting of multiple electrodes and the gate of the field effect transistor can be considered as a synaptic connection of the neural network.

A signal transmitted from a plurality of electrodes, that is, a neuron is converted into a chemical substance (ion) in an ionic conductor, which is detected by a gate of a field effect transistor and converted into an electric signal again. This synaptic connection has the following properties. (1) The field effect transistor has a threshold voltage. That is, the field-effect transistor does not turn on unless the pH in the ionic conductor is above (or below) a certain value. Therefore, if this threshold voltage is set to an appropriate value, when signals from multiple neurons (electrodes) are transmitted to synaptic connections, the transistor will not turn on unless a certain number of neuron signals are input, That is, the signal is not transmitted to the next neuron. Therefore, the synaptic connection according to this embodiment has a threshold value.

(2) Inhibitory synapses or excitatory synapses can be formed by setting the pH in the ionic conductor to an appropriate value in advance. That is, if the pH in the ionic conductor is set to a value close to the pH value corresponding to the threshold value of the field effect transistor, the transistor is turned on by a slight neuron signal and the signal is transmitted to the next neuron. . That is, it becomes an excitatory synapse. On the other hand, if the pH in the ionic conductor is set to a value greatly different from the pH value corresponding to the threshold value of the field effect transistor, the transistor will not turn on easily even if many neuronal signals are transmitted to the synapse. , The signal is hard to be transmitted. That is, it becomes an inhibitory synapse.

Further, by controlling the positive / negative of the signal transmitted to the synaptic bond, it is possible to control the concentration of hydrogen ion and hydroxide ion generated in the ionic conductor, and to form an inhibitory or excitatory synapse. can do. As described above, the synaptic connection according to this example has plasticity. (3) The electrode paired with the electrode arranged at the synapse coupling part is installed at another part in the ionic conductor. Therefore, when a neuron signal is transmitted and the pH of the synaptic junction changes, it takes a long time until the entire pH in the ionic conductor becomes uniform.

That is, the synapse state immediately after the neuron signal is transmitted is maintained for a certain period of time. Even if the power of an electronic element such as a field effect transistor is turned off, the pH state in the ionic conductor is maintained, so that the memory becomes a nonvolatile memory. As described above, the synaptic connection according to this example has a function corresponding to short-term memory. By utilizing such characteristics, it is possible to realize a neural circuit element having characteristics equivalent to a neural network by using the element according to this embodiment.

FIG. 8 is a sectional view of an integrated electrochemical circuit showing the eighth embodiment of the present invention. In this embodiment,
The insulating film 4 is formed on the surface of the silicon substrate 1, and the insulating film 4 is formed.
The first ion conductor 24 is formed on the top. A second ion conductor 25 is formed at one end of the ion conductor 24 so as to come into contact with the first ion conductor. The contact surface of the first and second ionic conductors is the junction of the different ionic conductors. Electrodes 26 and 27 are formed at the ends of the respective ion conductors opposite to the junction. When a voltage is applied between the electrodes 26 and 27, different kinds of ions move in the first and second ionic conductors.

At the junction between the first and second ionic conductors, different kinds of ions interact with each other such as binding due to the formation of salt, and the current-voltage characteristic of this element becomes non-linear. It is also possible to exhibit rectification characteristics by combining ion conductors, and it can be used as an element element of an integrated Iono-electron Device. By using a plurality of the above elements in combination, or in combination with a conventional electronic element, it is possible to realize a function that cannot be realized by a conventional integrated circuit made of only a semiconductor.

FIG. 9 is a diagram showing the first effect of the integrated electrochemical circuit according to the present invention. Using the element shown in the first embodiment, the input voltage between the electrodes 7 and 8 is shown. It shows the output voltage of the field effect transistor when is applied. Here, the source follower circuit is configured by the field effect transistor, and the gate potential change is used as it is as the output voltage. As a result, a gentle delay characteristic waveform having a time delay with respect to the step input voltage can be obtained. In addition, the current-voltage characteristics of this element exhibit hysteresis and have a memory effect. This is the basic operation of this device, and by combining these, an integrated Iono-electron Device having a function that has not been available can be realized.

FIG. 10 is a diagram showing the second effect of the integrated electrochemical circuit according to the present invention. Using the element shown in the seventh embodiment, eight pairs of electrodes, that is, neurons are ionized. It shows the output signal of the next neuron, that is, the field effect transistor, when the signal is applied to each neuron after delaying the signal for a predetermined time by being installed in a conductor. Here, even if a signal is transmitted from five neurons, the next neuron does not fire (signal is generated), but it fires when the sixth neuron signal is applied. That is, it was confirmed that the synapse according to this example has a threshold value. It is needless to say that each of the above-mentioned embodiments shows an example of the present invention, and the present invention should not be limited to these.

[0027]

As described above in detail, according to the present invention, by using ions in addition to electrons and holes as an information carrier, ionic conduction in an ionic conductor and mutual interaction between ions and electrons can be achieved. It is possible to provide characteristics that cannot be obtained by an integrated circuit using only conventional semiconductors, such as actions, and it is possible to realize an integrated Iono-electron Device having characteristics such as memory effect, hysteresis, and plasticity. By using it complementarily with the circuit, it is possible to provide an information processing system having a new function, and it is possible to realize an integrated electrochemical circuit.

[Brief description of drawings]

FIG. 1 is a configuration diagram according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram according to a seventh embodiment of the present invention.

FIG. 8 is a configuration diagram according to an eighth embodiment of the present invention.

FIG. 9 is a diagram showing a first effect of the present invention.

FIG. 10 is a diagram showing a second effect of the present invention.

[Explanation of symbols]

 1 Silicon Substrate 2 Source Region 3 Drain Region 4 Insulating Film 5 Ion Conductor 6-12 Metal Electrode 13 Spacer 14 Glass Substrate 15 Liquid Ion Conductor 16-21 Metal Electrode 22 Gate Part 23-27 Metal Electrode

Claims (8)

[Claims] 1. An electronic circuit or an electronic device formed on a substrate, comprising an ion-electron conversion device for converting at least one ion conductor on the substrate to convert ions into electrons or electrons to ions. An integrated electro-chemical circuit, characterized in that it is arranged so as to connect an electronically conductive electrode of an electronic circuit or an electronic element and the ionic conductor. 2. An ion conductor is provided on a semiconductor substrate on which an integrated circuit is formed, directly or through an insulating film, and is brought into contact with the ion conductor to convert ions into electrons or electrons into ions. An integrated electrochemical circuit, characterized in that it is provided with an electronic conversion element. 3. In a semiconductor substrate having at least one field effect transistor formed thereon, an ion conductor is provided on the gate insulating film of the channel portion of the field effect transistor so as to intersect with the channel portion, and the ion conductor is provided. An integrated electro-chemical circuit, comprising an ion-electron conversion element which is brought into contact with a conductor to convert ions into electrons or electrons into ions. 4. In a semiconductor substrate having a plurality of field effect transistors formed thereon, an ion conductor is provided on the gate insulating film of the channel portion of the first field effect transistor so as to intersect with the channel portion, and the ion conductor is provided. An ion-electron conversion element for contacting a conductor to convert ions to electrons or electrons to ions is provided, and the ion-electron conversion element is connected to an output terminal of a second field effect transistor. Integrated electronic chemical circuit. 5. The substrate is made of silicon, germanium,
5. The integrated electronic chemical circuit according to claim 1, which is a semiconductor such as gallium arsenide or the like, an inorganic insulator such as glass or sapphire, or an organic insulator such as epoxy resin or polyvinyl chloride. 6. The ion-electron conversion element is an element which has at least one conductive electrode and which converts an electron into an ion or an ion into an electron by an electrode reaction. The integrated electrochemical circuit according to any one of 1. 7. The integrated electrochemical circuit according to claim 1, wherein the ionic conductor is an inorganic or organic solid electrolyte or a solution containing an electrolyte. 8. The integrated device according to claim 6, wherein the material forming the conductive electrode is platinum, gold, silver, iridium, ruthenium, carbon, or a combination of two or more of the above materials. Electronic chemical circuit.