KR101394488B1 - Dynamic Ram Using Electrolyte - Google Patents

Abstract

The dynamic RAM according to the present invention includes an information storage element including a first electrode, a reference electrode, and an electrolyte positioned between the first electrode and the reference electrode; A word line driver connected to the gate of the transistor and controlling the turn-on / turn-off of the pass transistor, and a sense amplifier connected to the other end of the pass transistor, .

Description

[0002] Dynamic Ram Using Electrolyte [

The present invention relates to a dynamic RAM using an electrolyte.

Dynamic RAM forms a capacitor in an integrated circuit and uses it as an information storage device. The capacitor may be a charged state or a discharged state, which generally represents either a 0 or a 1 bit. Because the capacitor leaks charge, the information stored in the capacitor eventually disappears unless it is periodically refreshed. Therefore, it is called Dynamic Random Access Memories (DRAM) because periodic refreshing is required in this way.

The dynamic RAM requires only one transistor and one capacitor to store one bit, which is advantageous in that it has a high degree of integration and configuration. However, a refresh circuit as described above is additionally required.

Typical dynamic RAM has been continuously integrated with the trend of highly integrated and high information density. That is, it is formed so as to have a small height and a high height in order to reduce the area occupied by the capacitors storing information and to improve the area of the electrodes forming the capacitors. Therefore, in a process of forming a capacitor, a capacitor is leaned and a defect such as a storage node bridge in which adjacent capacitors are electrically connected to each other occurs.

It is an object of the present invention to propose a dynamic RAM structure using an information storage element having a high capacitance without forming an information storage element at a high aspect ratio in order to solve the disadvantages of such a conventional dynamic RAM.

Another object of the present invention is to propose a structure of a dynamic RAM which can be formed at a lower height than a capacitor used in a high conventional dynamic ram, thereby reducing the difficulty of the manufacturing process and increasing the yield. It is one of the purposes of the invention.

The dynamic RAM according to the present invention includes an information storage element including a first electrode, a reference electrode, and an electrolyte positioned between the first electrode and the reference electrode; A word line driver connected to the gate of the transistor and controlling the turn-on / turn-off of the pass transistor, and a sense amplifier connected to the other end of the pass transistor, .

In one embodiment, the device further comprises conductive nano particles located within the electrolyte.

In one embodiment, the conductive nanoparticle is a carbon nanoparticle.

In one embodiment, the first electrode is a material that does not cause a redox reaction with the electrolyte.

In one embodiment, the first electrode is formed of any one of gold (Au), platinum (Pt), and graphene.

In one embodiment, the apparatus further comprises a write unit including a write transistor for writing information to the information storage element, wherein the write transistor is connected at one end to a write voltage source and at the other end to the information storage element The transistor is connected to a node to which the transistor is connected, and the gate is turned on when it is connected to the write driver and writes information to the information storage element.

The precharge unit may further include a precharge unit including a precharge transistor for charging a line connecting the information storage element and the transistor to a predetermined voltage, wherein the precharge transistor has a precharge voltage source And the other end is connected to a node to which the information storage element and the pass transistor are connected and the gate is connected to the precharge driver and turned on when charging the line with a constant voltage.

The dynamic RAM according to the present invention includes an information storage element including a silicon oxide film, an electrolyte contained in the silicon oxide film, and a metal electrode for applying a voltage to the electrolyte, a pass transistor connected at one end to the information storage element, And a sense amplifier connected to the other end of the transistor. The word line driver controls the turn-on / turn-off of the pass transistor.

In one embodiment, the metal electrode changes the hydrogen ion concentration of the electrolyte by applying the voltage.

In one embodiment, the surface potential of the silicon oxide film is different depending on the hydrogen ion concentration of the electrolyte.

In one embodiment, the sense amplifier includes an ISFET for receiving a surface potential of the oxide film and outputting it as an electrical signal.

In one embodiment, the apparatus further comprises a write unit including a write transistor for writing information to the information storage element, wherein the write transistor is connected at one end to a write voltage source and at the other end to the information storage element The transistor is connected to a node to which the transistor is connected, and the gate is turned on when it is connected to the write driver and writes information to the information storage element.

The precharge unit may further include a precharge unit including a precharge transistor for charging a line connecting the information storage element and the transistor to a predetermined voltage, wherein the precharge transistor has a precharge voltage source And the other end is connected to a node to which the information storage element and the pass transistor are connected and the gate is connected to the precharge driver and turned on when charging the line with a constant voltage.

According to the present invention, there is an advantage that a dynamic RAM having a high capacitance and stable operation even if formed with a low aspect ratio is provided.

The information storage device having the high capacitance by the dynamic RAM according to the present invention prolongs the information storage time, and the refresh cycle can be extended, thereby reducing power consumption.

1 is a cross-sectional view illustrating an outline of an information repository according to a first embodiment of the present invention.
2 is a schematic diagram illustrating an operation of an information repository according to the first embodiment of the present invention.
3 is a schematic diagram showing an outline of a dynamic RAM according to an embodiment of the present invention.
4 is a schematic diagram of an information repository used in a dynamic RAM according to a second embodiment of the present invention.
5 is a schematic diagram showing an outline of a dynamic RAM according to a second embodiment of the present invention.

The description of the present invention is merely an example for structural or functional explanation, and the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, the embodiments are to be construed as being variously embodied and having various forms, so that the scope of the present invention should be understood to include equivalents capable of realizing technical ideas.

Meanwhile, the meaning of the terms described in the present application should be understood as follows.

The terms "first "," second ", and the like are used to distinguish one element from another and should not be limited by these terms. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "on" or "on" another element, it may be directly on top of the other element, but other elements may be present in between. On the other hand, when an element is referred to as being "in contact" with another element, it should be understood that there are no other elements in between. On the other hand, other expressions that describe the relationship between components, such as "intervening" and "intervening", between "between" and "immediately" or "neighboring" Direct neighbors "should be interpreted similarly.

It should be understood that the singular " include "or" have "are to be construed as including a stated feature, number, step, operation, component, It is to be understood that the combination is intended to specify that it is present and not to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

Each step may take place differently from the stated order unless explicitly stated in a specific order in the context. That is, each step may occur in the same order as described, may be performed substantially concurrently, or may be performed in reverse order.

The drawings referred to for explaining embodiments of the present disclosure are exaggerated in size, height, thickness, and the like intentionally for convenience of explanation and understanding, and are not enlarged or reduced in proportion. In addition, any of the components shown in the drawings may be intentionally reduced, and other components may be intentionally enlarged.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Terms such as those defined in commonly used dictionaries should be interpreted to be consistent with the meanings in the context of the relevant art and can not be interpreted as having ideal or overly formal meaning unless explicitly defined in the present application .

Hereinafter, an embodiment of a dynamic RAM according to a first embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an overview of an information storage device 100 according to a first embodiment of the present invention. FIG. 2 is a schematic view for explaining the operation of the information storage device 100 according to the first embodiment of the present invention. to be. Referring to FIGS. 1 and 2, the information storage device 100 includes a first electrode 120, a reference electrode 170, and an electrolyte 160 disposed between the first electrode and the reference electrode. In one embodiment, the information storage element 100 further comprises conductive nano particles 140.

2A, when a positive potential is applied to the first electrode 120, anions 162 are induced at a predetermined distance from the surface of the first electrode 120 to form an OHP (Outer Helmholtz Plane) do. In addition, a dielectric polarization occurs between the OHP formed by the anions and the first electrode 120 due to the electric field. Accordingly, when the first electrode 120 and the OHPs formed by the anions are regarded as electrodes, the structure of the capacitor in which the dielectrics are located between the electrodes and the electrodes is similar. That is, the OHPs formed by the first electrode 120 and the ions function as electrodes, and the material between the electrodes and the OHP functions as a dielectric material. Although not shown, when a negative potential is applied to the first electrode, positive ions 162 are induced at a position spaced a predetermined distance from the surface of the first electrode 120 to form an OHP (Outer Helmholtz Plane) A dielectric polarization due to an electric field occurs between the OHPs. Therefore, it functions as a capacitor.

Referring to FIG. 2B, in one embodiment, conductive nanoparticles 140 are positioned between the first electrode and the reference electrode. 2B is a diagram showing a state in which a positive potential is applied to the first electrode. The conductive nanoparticle 140 is electrically conductive and is electrically connected to the first electrode 120 even when the conductive nanoparticle 140 is in contact with the first electrode 120 or in contact with the conductive nanoparticle 140 in contact with the first electrode. Accordingly, if a potential is applied to the first electrode 120, the same potential is applied to each of the conductive nanoparticles, so that the OHPs of the anions are formed at a distance from the surface of each conductive nanoparticle, And an OHP of anions, a dielectric polarization occurs due to an electric field. Therefore, the case shown in FIG. 2B also functions as a capacitor as in FIG. 2A.

The capacitance of the capacitor thus formed can be calculated as shown in Equation 1 below.

It can be seen that the capacitance increases as the area of the opposing electrode increases and increases as the distance between the electrodes decreases. The distance d between the electrodes of the capacitor shown in FIG. 2A is determined by the distance between the OHPs from the surface of the first electrode, and the distance between the electrodes of the capacitor shown in FIG. 2B is determined by the distance between the surface of the conductive nanoparticle 140 and the OHP It is determined by distance. Since this distance is generally about the size of a molecule, a capacitor having a relatively high capacitance can be formed as compared with a general capacitor.

2B, the area of the electrode increases due to the electrical connection between the conductive nanoparticle 140 and the electrode, unlike the case of FIG. 2A. Therefore, it can be seen that the capacitance increases because the area of the electrode increases as compared with the capacitance of the capacitor formed in FIG.

1 and 2, the first electrode 170 is in contact with the electrolyte. Therefore, when the redox reaction occurs between the electrolyte and the first electrode, the stored information leaks in the form of a leakage current. Therefore, the first electrode is formed of a polarizable material that does not cause a redox reaction with the electrolyte. The polarizable material may be, for example, gold (Au), platinum (Pt), and graphene. The conductive nanoparticles 140 are also contacted with the electrolyte to prevent the oxidation-reduction reaction from occurring, and the conductive nanoparticles 140 are formed of a conductive material. As an example, conductive nanoparticles may be carbon nanoparticles.

Since the charges induced in the capacitors shown in Figs. 2A and 2B change over time, the information eventually stored in the information storage element 100 will disappear. Therefore, it is necessary to refresh the information stored in the information storage element at a constant period. However, the refresh operation is a technique used in a general dynamic RAM using a capacitor as an information storage element, and is omitted for the sake of brevity.

Conventional DRAMs have capacitors formed to have a high height in a narrow area in accordance with the trend of high density and high integration. Since the capacitor is formed at a high aspect ratio, defects such as a capacitor tilting or an electrical connection between an adjacent capacitor and a capacitor are generated, and the yield is accordingly low. However, according to the present invention, it is possible to obtain an information storage device having a large capacitance due to a low inter-electrode distance even when the information storage device 100 is formed with a low aspect ratio, and further, An information repository can be obtained. Further, since the information storage device has a high capacitance, it takes a long time to store information as compared with a capacitor used in a conventional dynamic RAM. Therefore, the refresh period for updating the information can be lengthened, and the power consumption can be reduced accordingly.

3 is a schematic diagram showing an outline of a dynamic RAM according to an embodiment of the present invention. Referring to FIG. 3, the dynamic RAM according to the embodiment of the present invention includes a first electrode 120, a reference electrode 180, and an electrolyte 160 disposed between the first electrode and the reference electrode. A pass transistor 200 connected at one end to the information storage element and a word line driver 300 connected to the gate of the pass transistor to control turn on / turn off of the transistor, And a sense amplifier 400 connected to the other end of the transistor. In one embodiment, the dynamic RAM according to the first embodiment of the present invention further includes a write unit 500 for performing a write to the dynamic RAM. The writing unit 500 is connected to a node to which the writing voltage Vw is applied and the other end to which the information storage element and the transistor are connected and the gate is connected to the writing driving unit, The write transistor 520 is turned on. In one embodiment, the reference electrode 180 applies a cell plate voltage.

The dynamic RAM according to the first embodiment of the present invention further includes a precharge unit 600 for charging a parasitic capacitance formed in a line connecting the information storage device 100 and the transistor to a constant voltage, Charge unit Vp is applied at one end and the other end is connected to a node to which the information storage element and the pass transistor are connected and the gate is connected to the precharge driver to charge the line at a constant voltage Charge transistor 620 that is turned on.

The outline of the writing operation to the dynamic RAM according to the first embodiment of the present invention will be described below. A write driver (not shown) applies a write signal (Write) to the write unit 500. The write transistor included in the write unit is turned on by a write signal applied by the write driver. Accordingly, since the write voltage Vw applied to one end of the write transistor by the write driver is conducted to the other end and is applied to the first electrode of the data storage device 100, a binary bit corresponding to the applied voltage can be stored have. During the writing operation, the precharge transistor 620 and the pass transistor 200 are turned off.

Hereinafter, a read operation outline for reading information stored in the dynamic RAM according to the first embodiment of the present invention will be described. A precharge driver (not shown) applies a precharge signal to the precharge unit 600. The precharge transistor 620 included in the precharge unit 600 is turned on by the precharge signal and therefore the precharge voltage Vp applied to one end of the precharge transistor 620 by the precharge driving unit is conductive And the parasitic capacitance formed in the line connecting the information storage element 100 and the precharge unit is filled with the precharge voltage Vp. During precharging, write transistor 520 and pass transistor 200 are turned off. After pre-charge, the pre-charge driver turns off the pre-charge transistor, and the word line driver 300 turns on the pass transistor 200. [ If the charge is not stored in the information storage element 100, the voltage of the line is drastically reduced, but if the charge is stored in the information storage element 100, the voltage change of the line is not large. Accordingly, the sense amplifier 400 can compare the voltage change of the line with a predetermined reference voltage and read the information stored in the information storage device.

Hereinafter, a dynamic RAM according to a second embodiment of the present invention will be described. 4 is a schematic diagram of an information storage device 1000 used in a dynamic RAM according to a second embodiment of the present invention. Referring to FIG. 4, the information storage element includes an oxide film 1200, an electrolyte 1600 contained in the oxide film, and a metal electrode 1300 applying a voltage to the electrolyte. In one embodiment, an oxide film can be formed in the silicon substrate 1100, and is formed, for example, from a silicon oxide (SiO 2) film. In one embodiment, a salt bridge 1500 is formed on top of the silicon substrate. The salting bridge 1400 functions to allow ions to flow in from the external electrolyte. The bridging (1400) is formed, for example, as a nafion membrane. In one embodiment, a reference electrode 1700 is located on top of the salt bridge 1400. The reference electrode 1700 applies a cell plate voltage to the reference voltage. The reference electrode is formed, for example, of metal. As another example, the reference electrode is formed of a silver-silver chloride electrode. In one embodiment, a metal interconnection 1350 is formed between the oxide film 1200 and the substrate 1100 to apply a potential evenly to the oxide film. The metal wiring includes, for example, any one of aluminum (Al), copper (Cu), and tungsten (W).

The metal electrode 1300 directly contacts the electrolyte 1600 to cause a redox reaction to change the hydrogen ion concentration of the electrolyte. The metal electrode includes, for example, any one of aluminum (Al), copper (Cu), and tungsten (W). As another example, the metal electrode may be coated with one material of aluminum (Al), copper (Cu), and tungsten (W).

In the oxide film 1200, an adsorption charge is formed according to the changed hydrogen ion concentration of the electrolyte 1600, and thus a surface potential is formed. The information stored in the information storage device 1000 can be detected by sensing the surface potential thus formed. The oxide film is formed, for example, as a non-conductive oxide film. As another example, the oxide film includes at least one of a tantalum oxide film (Ta2O5), an aluminum oxide film (Al2O3), a nitride film (Si3O4), and a silicon oxide film (SiO2).

An information storage mechanism of the information storage device 1000 having such a structure will be described. The oxide film applicable to the present invention may be a nonconductive oxide film. However, for a sufficient explanation of the present invention, a case where a silicon oxide film (SiO2) is adopted as an oxide film in the following chemical formula will be described. When information is written to the information storage element, a write driver (not shown) applies a voltage to the electrolyte 1600 through the metal electrode 1300. This is for the purpose of explanation and is not intended to limit the scope of the invention. As the voltage is applied to the electrolyte 1600, the hydrogen ion concentration (pH) of the electrolyte changes, and a reaction such as the following formula occurs between the oxide film and the electrolyte.

는 산화막의 표면전위(surface potential), [H+]는 전해질 용액내 H+ 이온의 농도, CDL은 전기이중층의 커패시턴스를 의미하며,

는 전해질과 산화막 계면에서의 흡착전하량(adsorption charge)을 의미한다.In the formula (1), kf1 and kf2 are respective positive reaction coefficients, kb1 and kb2 are respective reverse reaction coefficients,

Is the surface potential of the oxide film, [H +] is the concentration of H + ions in the electrolyte solution, and CDL is the capacitance of the electric double layer,

Means the adsorption charge at the interface between the electrolyte and the oxide film.

)를 변화시킨다. 이와 같이 금속 전극을 통하여 전해질내의 수소이온농도를 변화시키면 그에 상응하는 산화막의 표면전위가 형성됨을 알 수 있고, 산화막의 표면전위를 검출하여 감지하면 정보저장소자(1000)에 저장된 정보를 읽을 수 있다.When a voltage is applied to the electrolyte through the metal electrode, a change in hydrogen ion concentration occurs in the electrolyte 1600, and a change in the hydrogen ion concentration forms an adsorption charge at the interface between the electrolyte 1600 and the oxide film 1200 The surface potential of the oxide film 1200,

). When the hydrogen ion concentration in the electrolyte is changed through the metal electrode, the surface potential of the corresponding oxide film is formed. When the surface potential of the oxide film is detected and sensed, information stored in the information storage device 1000 can be read .

Since the hydrogen ion concentration in the electrolyte 1600 changes with passage of time, information stored in the information storage element 1000 will eventually disappear. Therefore, it is necessary to refresh the information stored in the information storage element at a constant period. However, the refresh operation is a technique used in a general dynamic RAM using a capacitor as an information storage element, and is omitted for the sake of brevity.

5 is a schematic diagram showing an outline of a dynamic RAM according to a second embodiment of the present invention. 5, the dynamic RAM according to the second embodiment of the present invention includes an information storage device 1000 including a silicon oxide film 1200, an electrolyte 1600, and a metal electrode 1300 for applying a voltage to the electrolyte, A pass transistor 2000 connected at one end to the information storage device, a word line driver connected to the gate of the pass transistor for controlling turn-on / turn-off of the pass transistor, And a sense amplifier 4000 connected thereto. In one embodiment, the dynamic RAM according to the second embodiment of the present invention further includes a write unit 5000 for performing a write to the dynamic RAM. The write unit 5000 has a write voltage Vw applied to one end thereof and a metal electrode 1300 connected to an information storage device. The other end of the write unit 5000 is connected to the write driver, And a write transistor 5200 turned on by a write signal (write) applied by the write driver when writing information to the write transistor.

The dynamic RAM according to the second embodiment of the present invention further includes a precharge unit 6000 for charging a line connecting the information storage element and the transistor at a constant voltage. The precharge unit 600 is supplied with a precharge voltage Vp applied to a precharge driving unit (not shown) at one end and connected to a node connected to the information storage device 1000 and the pass transistor And the gate includes a precharge transistor 6200 connected to the precharge driver and turned on by a precharge signal (Precharge) applied by the precharge driver in performing precharge.

The outline of the writing operation to the dynamic RAM according to the second embodiment of the present invention will be described below. The write driver applies a write signal (Write) to the write unit 5000. The write transistor 5200 included in the write unit 5000 is turned on by a write signal. Accordingly, the write voltage Vw applied to one end of the write transistor is conducted to the other end, and a constant voltage is applied to the metal electrode 1300 of the information storage element 1000. [ Since the hydrogen ion concentration of the electrolyte changes according to the voltage applied by the metal electrode 1300, the surface potential of the oxide film 1200 also changes in accordance with the changed hydrogen ion concentration. Thus, the information storage element 1000 can store binary bits corresponding to the applied voltage.

The outline of the reading operation of information stored in the dynamic RAM according to the second embodiment of the present invention will be described below. The precharge driver (not shown) applies a precharge signal to the precharge unit 6000. Since the precharge transistor 6200 included in the precharge unit 600 is turned on by the precharge signal, the precharge voltage Vp applied to one end of the precharge transistor by the precharge driving unit becomes the other end of the precharge transistor To the line connecting the information storage element 100 and the precharge unit. Therefore, the parasitic capacitance formed in the line connecting the information storage element 1000 and the precharge unit 6000 is charged with the precharge voltage Vp. During the precharge, the pass transistor 5200 is turned off. After the pre-charge, the pre-charge driver turns off the pre-charge transistor, and the word line driver 3000 turns on the pass transistor 2000. If the charge is not stored in the information storage element 1000, the voltage of the line is drastically reduced. However, if the charge is stored in the information storage element 1000, the voltage change of the line is stored in the information storage element 1000 It is not big compared to the state without. Therefore, the sense amplifier 4000 can compare the voltage change of the line with a predetermined reference voltage and read the information stored in the information storage element. In one example, the sense amplifier 4000 may include an ISFET (Ion Sensitive Field Effect Transistor) that senses the surface potential of the oxide film 1600 and amplifies and outputs the surface potential. The ISFET includes an inverter including PMOS and NMOS, for example, and senses a surface potential formed on the surface of the oxide film and outputs an electrical signal obtained by amplifying the surface potential.

The Vref potential connected to one end of the sense amplifier is a potential value that is used as a reference to determine whether the stored information read from the surface potential formed on the oxide film surface is "0" or "1" in the binary information. Therefore, the Vref potential can vary depending on the oxide film, the electrolyte, the metal electrode, and the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It will be appreciated that other embodiments are possible. Accordingly, the true scope of the present invention should be determined by the appended claims.

100: information storage element 120: first electrode
140: conductive nanoparticles 160, 1600: electrolyte
162: Negative ion 164: Cation
170, 1700: reference electrode 200, 2000: pass transistor
300, 3000: Word Line Driver 400, 4000: Sense Amplifier
500, 5000: Write unit 520, 5200: Write transistor
600, 6000: precharge unit 620, 6200: precharge transistor
1000: information storage element 1100: substrate
1200: oxide film 1300: metal electrode
1350: metal wiring
1400:

Claims (15)

A capacitor including a first electrode, a reference electrode, and an electrolyte positioned between the first electrode and the reference electrode, the capacitor being formed by the electrolyte and the first electrode;
A pass transistor connected at one end to the capacitor;
A word line driver coupled to the gate of the transistor to control turn-on / turn-off of the pass transistor; And
And a sense amplifier connected to the other end of the pass transistor. The method according to claim 1,
Further comprising conductive nanoparticles positioned within the electrolyte. 3. The method of claim 2,
Wherein the conductive nanoparticles are carbon nanoparticles. The method according to claim 1,
Wherein the first electrode is a material that does not cause a redox reaction with the electrolyte. The method according to claim 1,
Wherein the first electrode is formed of one of gold (Au), platinum (Pt), and graphene. The method according to claim 1,
Further comprising a write unit including a write transistor for writing information to the capacitor,
Wherein the write transistor is turned on at a time when the write transistor is connected to a write voltage source and the other end is connected to the other end of the pass transistor and the gate is connected to the write driver to write information to the information storage device. The method according to claim 1,
And a precharge unit including a precharge transistor for charging a line connecting the capacitor and the transistor to a predetermined voltage,
The precharge transistor has one end connected to a precharge voltage source and the other end connected to the other end of the pass transistor. The gate is connected to a precharge driver, and when the line is charged with a constant voltage, Dynamic RAM. An information storage element comprising an oxide film, an electrolyte contained in the oxide film, and a metal electrode for applying a voltage to the electrolyte;
A pass transistor connected at one end to the information storage element;
A word line driver coupled to the gate of the pass transistor to control turn-on / turn-off of the pass transistor; And
And a sense amplifier connected to the other end of the transistor. 9. The method of claim 8,
Wherein the metal electrode changes the hydrogen ion concentration of the electrolyte by applying the voltage. 9. The method of claim 8,
Wherein the oxide film has surface potentials differently formed depending on a hydrogen ion concentration of the electrolyte. 9. The method of claim 8,
Wherein the sense amplifier includes an ISFET (Ion Sensitive Field Effect Transistor) that receives a surface potential of the oxide film and outputs the received electric signal as an electrical signal.
9. The method of claim 8,
The oxide film is, for example, a non-conductive oxide film. 9. The method of claim 8,
Wherein the oxide film includes at least one of a tantalum oxide film (Ta2O5), an aluminum oxide film (Al2O3), a nitride film (Si3O4), and a silicon oxide film (SiO2). 9. The method of claim 8,
Further comprising a writing unit including a writing transistor for writing information to the information storage element,
Wherein the write transistor is turned on at a time when the write transistor is connected to a write voltage source and the other end is connected to the other end of the pass transistor and the gate is connected to the write driver to write information to the information storage device. 9. The method of claim 8,
A precharge unit including a precharge transistor for charging a line connecting the information storage element and the transistor to a predetermined voltage,
The precharge transistor has one end connected to a precharge voltage source and the other end connected to the other end of the pass transistor. The gate is connected to a precharge driver, and when the line is charged with a constant voltage, Dynamic RAM.

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