Electrochemical memory cell and neural network memory including same

Abstract

The invention relates to an electrochemical memory cell and a neural network memory including the same. An electrochemical memory cell may include an electrochemical channel, a gate, and an interface layer. The electrochemical channel may include a protruding surface having a fin shape. The gate may overlap a protruding surface of the electrochemical channel. An interface layer may be formed between the protruding surface of the electrochemical channel and the gate. The interface layer may control ion exchange between the gate and the electrochemical channel for memory operations based on the gate voltage.

Description

[0001] Cross - reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10 - 2023 - 0160371, filed with the Korean Intellectual Property Office on November 20, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] Various embodiments generally relate to semiconductor memory technologies, and more particularly, to electrochemical storage cells and neural network storage devices including the same. Background Art

[0004] In the von Neumann computer architecture, frequent movement of a large amount of data between a processor and a memory may cause long latency times and high power consumption. To solve these problems, an analog cross - point array structure can be proposed.

[0005] An analog cross - point array may include a plurality of memory cells programmed by a plurality of conductances. The analog cross - point can calculate vector - matrix multiplication and vector outer - product update in an analog manner using time complexity.

[0006] Non - volatile memory can be mainly used for the memory cells of an analog cross - point array. Recently, as artificial synaptic weights in neural network storage devices become more and more important, electro - chemical random access memory (ECRAM) can be widely used for the memory cells of an analog cross - point array.

[0007] An electrochemical storage cell can perform a storage operation by ion exchange with a channel according to a gate voltage (or gate current).

[0008] However, as the integration degree of semiconductor storage devices increases, the size of an electrochemical storage cell may need to be reduced. In addition, it may be necessary to ensure an exact ratio between a set resistance and a reset resistance in the electrochemical storage cell and fast operation characteristics. Summary of the Invention

[0009] According to an example embodiment, an electrochemical storage cell can be provided. The electrochemical storage cell can include an electrochemical channel, a gate, and an interface layer. The electrochemical channel can include a protruding surface having a fin shape. The gate can overlap the protruding surface of the electrochemical channel. The interface layer can be formed between the protruding surface of the electrochemical channel and the gate. The interface layer can control ion exchange for a storage operation between the gate and the electrochemical channel based on a gate voltage.

[0010] According to an example embodiment, an electrochemcial storage unit can be provided. The electrochemcial storage unit can include an electrochemcial fin structure, a gate, a source, a drain, an electrolyte layer, and an ion storage layer. The electrochemcial fin structure can protrude from a surface of a lower layer. The gate can overlap a channel region of the electrochemcial fin structure. The source can be formed in the electrochemcial fin structure on one side of the gate. The drain can be formed in the electrochemcial fin structure on the other side of the gate. The electrolyte layer can be located between the channel region and the gate. The electrolyte layer can contact both sidewalls and an upper surface of the protruding channel region. The ion storage layer can be formed between the electrolyte layer and the gate to generate and receive ions for a storage operation together with the gate. The electrolyte layer can selectively provide ions to the channel region through both sidewalls and the upper surface of the channel region based on a gate voltage.

[0011] According to an example embodiment, a neural network storage device can be provided. The neural network storage device can include a plurality of word lines, a plurality of bit lines, a plurality of source lines, and electrochemcial storage units. The word lines can extend parallel to each other in a first direction. The bit lines can extend parallel to each other in a second direction intersecting the first direction. The source lines can extend parallel to at least one of the first direction and the second direction. The electrochemcial storage units can be arranged at intersection portions between the word lines, the bit lines, and the source lines.

[0012] The electrochemcial storage unit can include an electrochemcial fin structure, a gate, a source, a drain, and an electrolyte layer. The electrochemcial fin structure can be protruding. The gate can overlap a channel region of the electrochemcial fin structure. The gate can be electrically connected to any one of the plurality of word lines selected. The source can be formed in the electrochemcial fin structure on one side of the gate. The source can be electrically connected to any one of the plurality of source lines selected. The drain can be formed in the electrochemcial fin structure on the other side of the gate. The drain can be electrically connected to any one of the plurality of bit lines selected. The electrolyte layer can be located between the channel region and the gate. The electrolyte layer can contact both sidewalls and an upper surface of the protruding channel region.

[0013] According to an example embodiment, an electrochemcial storage unit having a fin structure can be used as a storage unit of a neural network storage device. Accordingly, the neural network storage device can have an improved integration density and improved on / off characteristics.

[0014] In addition, ions can be rapidly exchanged through a protruding portion of a fin channel overlapping with the gate. Ions introduced on a large surface area can rapidly diffuse into a narrow channel. Accordingly, the neural network storage device can have a fast operation speed and low power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other aspects, features, and advantages of the subject matter of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 is a circuit diagram showing a neural network storage device according to an embodiment of the present disclosure;

[0017] Figure 2 is a perspective view showing an electrochemical storage cell according to an embodiment of the present disclosure;

[0018] Figure 3A and Figure 3B is a cross-sectional view showing a write operation of an electrochemical storage cell according to an embodiment of the present disclosure;

[0019] Figure 4A and Figure 4B is a cross-sectional view showing a read operation of an electrochemical storage cell according to an embodiment of the present disclosure;

[0020] Figure 5 is a graph showing the conductance of a storage cell according to an embodiment of the present disclosure; and

[0021] Figure 6 is a graph showing the change in conductance of a storage cell according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] Various embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. The accompanying drawings are schematic illustrations of various embodiments (and intermediate structures). Accordingly, variations in the configurations and shapes illustrated due to, for example, manufacturing techniques and / or tolerances are to be expected. Accordingly, the described embodiments should not be construed as limited to the specific configurations and shapes shown herein, but may include deviations in configurations and shapes that do not depart from the spirit and scope of the invention as defined in the appended claims.

[0023] The present invention is described herein with reference to cross-sectional illustrations and / or plan views of idealized embodiments of the invention. However, embodiments of the present invention should not be construed as limiting the inventive concept. Although some embodiments of the present invention will be shown and described, those of ordinary skill in the art will understand that changes can be made to these embodiments without departing from the principles and spirit of the present invention.

[0024] As used herein, the term "configuration" refers to the size, shape, material composition, orientation, or arrangement of one or more of at least one structure and at least one device in a predetermined manner to facilitate the operation of one or more of the structure and device.

[0025] As used herein, the terms "vertical", "longitudinal", "horizontal", and "lateral" refer to the principal planes of a structure and are not necessarily defined with respect to the earth's gravitational field. A "horizontal" or "lateral" direction is a direction that is substantially parallel to the principal plane of the structure, while a "vertical" or "longitudinal" direction is a direction that is substantially perpendicular to the principal plane of the structure. The principal plane of a structure is defined by the surface of the structure that has a relatively large area compared to the other surfaces of the structure. Referring to the accompanying drawings, a "horizontal" or "lateral" direction may be perpendicular to the indicated "Z" axis and may be parallel to the indicated "X" axis and / or parallel to the indicated "Y" axis; and a "vertical" or "longitudinal" direction may be parallel to the indicated "Z" axis, may be perpendicular to the indicated "X" axis, and may be perpendicular to the indicated "Y" axis.

[0026] As used herein, for ease of description, spatial relative terms, such as "beneath", "below", "bottom", "under", "above", "upper", "top", "front", "rear", "left", "right", etc., may be used to describe the relationship of one element or feature to another element or feature, as shown in the figures. Unless otherwise specified, spatial relative terms are intended to cover different orientations of the material in addition to the orientation depicted in the figures. For example, if the material in the figures is inverted, an element described as "beneath" or "below" or "under" or "at the bottom of" another element or feature will be oriented "above" or "at the top of" the other element or feature. Thus, depending on the context in which the term is used, the term "below" can cover both upward and downward orientations, which will be apparent to those of ordinary skill in the art. The material may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped) and the spatial relative descriptors used herein are to be interpreted accordingly.

[0027] As used herein, the singular forms "a", "the", and "said" are also intended to include the plural forms unless the context clearly dictates otherwise.

[0028] As used herein, the phrases "coupled to" and "connected to" refer to structures that are operably connected to each other, such as being electrically connected either directly by an ohmic connection or indirectly (e.g., through another structure).

[0029] As used herein, the term "substantially" with respect to a given parameter, property, or condition means and includes that which would be understood by one of ordinary skill in the art to meet the given parameter, property, or condition with a degree of variation, such as within an acceptable tolerance. By way of example, depending on the particular parameter, property, or condition that is substantially met, the parameter, property, or condition may be met at least 90.0%, at least 95.0%, at least 99.0%, at least 99.9%, or even 100.0%.

[0030] Figure 1 is a circuit diagram showing a neural network storage device according to an embodiment of the present disclosure.

[0031] Referring to Figure 1 , the neural network storage device 10 of the exemplary embodiment may include a plurality of word lines and a plurality of bit lines crossing the word lines The neural network storage device 10 may further include a plurality of source lines SL1 to SLm.

[0032] For example, the plurality of word lines may be arranged parallel to each other along a first direction D1. The plurality of bit lines may be arranged parallel to each other along a second direction D2, and the second direction D2 is substantially perpendicular to the first direction D1. The plurality of source lines may extend along the first direction D1 or the second direction D2. In the exemplary embodiment, the plurality of source lines SL1 to SLm may be arranged along the second direction D2. Alternatively, the source lines SL1 to SLm may be commonly connected to a substrate bias line.

[0033] The neural network storage device 10 may include a plurality of storage cells MC. The plurality of storage cells MC may be respectively arranged at the intersection portions of the plurality of word lines WL1 to WLn, the plurality of bit lines BL1 to BLm, and the plurality of source lines SL1 to SLm.

[0034] Each storage cell MC may include a three-terminal element respectively connected to a word line, a bit line, and a source line. In the exemplary embodiment, the storage cell MC may have a switching and storage function including a gate, a drain, and a source as three terminals. The gate may be electrically connected to the word line. The drain may be electrically connected to the bit line. The source may be electrically connected to the source line.

[0035] The gate may receive an operation voltage (e.g., a programming voltage for a set operation and a reset operation) and a read voltage. For example, the storage operation of the storage cell may be performed by the resistance change of the storage cell according to an electrochemical reaction. The electrochemical reaction may be generated by ions, and the ions are generated by the programming voltage. The storage cell MC may be an electrochemical storage cell. In the following description, the reference numeral MC may represent an electrochemical storage cell.

[0036] The plurality of word lines may be connected to an input control block (not shown). The word line of the selected address may receive an operation voltage. The plurality of bit lines may be connected to an output control block (not shown) to sense the conductance of the storage cell at the selected address. The resistance of the storage cell MC may be determined by the output current of the storage cell MC. The resistance of the storage cell may mean the conductance of the storage cell MC.

[0037] Figure 2 is a perspective view showing an electrochemical storage cell according to an embodiment of the present disclosure.

[0038] Referring to Figure 2 , an electrochemical storage cell MC may be formed on a lower layer 110. The electrochemical storage cell MC may include an electrochemical fin structure 120 and a gate 160.

[0039] The lower layer 110 may include at least one semiconductor layer, a semiconductor substrate, etc. In an exemplary embodiment, the lower layer 110 may include a silicon layer, a single-crystalline silicon substrate, etc. Alternatively, the lower layer 110 may include Ge, SiC, GaAs, GaP, InP, InAs, InSb, SiGe, GaAsP, AlInAs, AlGaAs, GaInAs, GaInP, GaInAsP, or a combination thereof. Additionally, the lower layer 110 may include a silicon-on-insulator (SOI) substrate, a silicon-germanium-on-insulator (SGOI) substrate, or a germanium-on-insulator (GOI) substrate, etc.

[0040] The electrochemical fin structure 120 may protrude from an upper surface of the lower layer 110 in a third (vertical) direction D3. For example, the electrochemical fin structure 120 may have a height extending in the third direction D3, a width extending in a first direction D1, and a length extending in a second direction D2. In an example, the electrochemical fin structure 120 may include an active region of the electrochemical storage cell MC.

[0041] For example, the electrochemical fin structure 120 may include a source S, a channel (not shown), and a drain D. The channel may be defined by a portion of the electrochemical fin structure 120 that overlaps with the gate 160. The source S may be located on one side of the channel. The drain D may be located on the other side of the channel. For example, the source S, the channel, and the drain D may be arranged side by side along the length direction of the electrochemical fin structure 120 (i.e., along the second direction D2). Additionally, the source S and the drain D may be separated from the gate 160. For example, the source S and the drain D may be insulated from the gate 160 by an insulating layer 130. Accordingly, a portion of the electrochemical fin structure 120 that is included in the active region of the electrochemical storage cell MC is a portion extending in the D3 direction from the insulating layer 130, and an outer surface of the channel structure protrudes from an upper surface of the insulating layer 130 and is covered by the gate 160. The channel may include a material having a resistance change characteristic related to a voltage applied to the gate 160 (e.g., a gate voltage).

[0042] The gate 160 may overlap the channel of the electrochemical fin structure 120. The gate 160 may extend in the first direction D1. In an embodiment, the gate 160 may be configured to surround the channel and the electrochemical fin structure 120 in a plan view (i.e., viewed along the D3 direction) in an area where the gate 160 and the electrochemical fin structure 120 overlap. The gate 160 may include a conductive material such as a metal. For example, the gate 160 may generate and receive ions based on a gate voltage. In addition, the gate 160 may be connected to the above reference Figure 1 Describes a portion of a word line of a memory cell MC.

[0043] The electrochemical storage cell MC may include an interface layer IF between the channel and the gate 160. The interface layer IF may be formed along the surface of the channel. The interface layer IF may selectively control ion exchange in a storage operation based on a gate voltage.

[0044] For example, the interface layer IF may transfer ions for storage operation to the channel. In addition, the interface layer IF may receive ions for storage operation from the channel, or may block the transfer of ions for storage operation based on the electric field between the channel and the gate 160.

[0045] The interface layer IF may include an electrolyte layer 140. The electrolyte layer 140 may include an insulating material having a plurality of grain boundaries. The electrolyte layer 140 may exchange ions between the gate 160 and the channel according to the gate voltage. In addition, the electrolyte layer 140 may act as a barrier to prevent ion diffusion. Alternatively, the interface layer IF may further include an ion storage layer 150 interposed between the electrolyte layer 140 and the gate 160. The ion storage layer 150 may generate and receive ions together with the gate 160. For example, the ion storage layer 150 may undergo an electrochemical reaction to generate ions according to the gate voltage. The ion storage layer 150 may store ions in a non-programming operation. The ion storage layer 150 may include a metal compound having oxygen ions, which may be used as ions for a storage operation. In an embodiment, the ion storage layer may be part of the gate 160.

[0046] Alternatively, at least one of the channel of the electrochemical fin structure 120, the gate 160, the electrolyte layer 140, and the ion storage layer 150 may include a material in which an electrochemical reaction occurs based on a gate voltage.

[0047] In an embodiment, the materials in the electrochemical fin structure 120, the electrolyte layer 140, and the ion storage layer 150 may be selected according to ions suitable for the storage operation. The memory cell may operate differently according to the type of ions used for the storage operation.

[0048] For example, ions used in storage operations may include O 2- Ions, H + ​​Ions and Li + ions.

[0049] When the electrochemcial fin structure 120, the electrolyte layer 140, and the ion storage layer 150 include, for example, an oxygen-containing material or a metal oxide material, the ions used in the storage operation may include O 2- ions. For example, the electrochemcial fin structure 120 may include at least one of WO 3 and TiO 2 . The electrolyte layer 140 may include at least one of HFOx, ZrO 2 , yttria-stabilized zirconia (YSZ). The ion storage layer 150 may include at least one of Ta 2 O 5 , TiO 2 and WO 3 .

[0050] For example, when the electrochemcial fin structure 120 includes at least one of WO 3 and 2D Mxene, the ions used in the storage operation may include H + ions. The electrolyte layer 140 may include a liquid or organic electrolyte material, such as a proton exchange membrane (PEM), a nafion membrane, a phosphosilicate glass (PSG), etc. The ion storage layer 150 may include at least one of Pd(Hx), Mg(Hx), and Y(YHx).

[0051] For example, when the electrochemcial fin structure 120 includes at least one of WO 3 , Li x-1 CO 2 and graphene, the ions used in the storage operation may include Li + ions. The electrolyte layer 140 may include an insulating material having Li.

[0052] In some embodiments, the gate 160 may operate as the ion storage layer 150 and include ions for the storage operation, and the electrochemcial storage unit may not have a separate ion storage layer 150.

[0053] Write operation

[0054] Figure 3A and Figure 3B are cross-sectional views showing a write operation of an electrochemcial storage unit according to an embodiment of the present disclosure. Figure 3A and Figure 3B are cross-sectional views taken along line I-I' in Figure 2 . Figure 3A and Figure 3BThe interface layer IF in [the device] can use the electrolyte layer 140 and the ion storage layer 150. The storage operation of an electrochemical storage cell using oxygen vacancies as ions for storage operations will be described below.

[0055] Referring to Figure 1 、 Figure 2 and Figure 3A , a positive programming voltage +Vpgm, i.e., a set voltage Vset, can be applied to the gate 160. A ground voltage can be applied to the source S and the drain D. The set voltage Vset can be applied to the gate 160 through a selected word line. The lower layer 110 below the electrochemical fin structure 120 and the channel region between the source S and the drain D can maintain a ground voltage level.

[0056] The set voltage Vset can be a positive voltage higher than the threshold voltage for initiating an electrochemical reaction in the gate 160, the ion storage layer 150, the electrolyte layer 140, and the channel 120a.

[0057] When the set voltage Vset is applied to the gate 160, an electrochemical reaction can occur between the gate 160 and the ion storage layer 150 to generate ions for storage operations from the ion storage layer 150. In an embodiment, the ions for storage operations can include oxygen vacancies Vo.

[0058] An electric field can be generated between the gate 160 that can receive the set voltage Vset and the source S and the drain D that can receive the ground voltage. According to the voltage difference and the generated electric field, oxygen vacancies Vo in the ion storage layer 150 can be supplied to the channel 120a through the electrolyte layer 140. The amount of oxygen vacancies in the channel 120a of the electrochemical fin structure 120 can increase, such that the electrochemical storage cell can switch to a low-resistance state, e.g., a set state.

[0059] As described above, the surface of the channel 120a can protrude from the upper surface of the insulating layer 130, and the surface of the channel 120a overlaps with the gate 160. Thus, the protruding surface (i.e., the two sidewalls and the upper surface shared by the channel 120a and the gate 160) can contact the interface layer IF and can exchange (transfer and receive) ions for storage operations. Compared with ion exchange in a two-dimensional (2D) electrochemical storage cell with a planar channel, since the channel 120a has a fin shape, the increase in the surface area overlapping with the gate 160 in a three-dimensional (3D) electrochemical storage cell is beneficial for faster ion exchange. As a result, the amount of time required to apply the set voltage can be reduced, leading to lower power consumption and fast storage operations, as well as increased operation speed.

[0060] In an embodiment, the channel 120a may have a fin or fin-like shape with a fine width to accommodate a high integration density, such that the channel 120a can be smaller than the channel of a 2D electrochemical storage cell in terms of channel length and channel volume.

[0061] Thus, ions for storage operations can be transferred to the channel 120a throughout the protrusion surface, and the channel 120a may have a relatively small width. Therefore, an electrochemical reaction can occur rapidly in the channel 120a. As a result, after applying a programming voltage, the channel resistance can be changed more quickly compared to the programming operation in a 2D electrochemical storage cell.

[0062] Refer to Figures 1 to 3B , a ground voltage can be applied to the source S and the drain D. A negative programming voltage -Vpgm, i.e., the reset voltage Vreset, can be applied to the gate 160.

[0063] The electrochemical reaction occurring between the channel 120a, the electrolyte layer 140, the ion storage layer 150, and the gate 160 can reset the electric field in a manner opposite to the SET operation between the channel 120a and the gate 160. Oxygen vacancies Vo in the channel 120a can be transferred to the ion storage layer 150 under the reset electric field. As the oxygen vacancies are transferred from the channel 120a to the ion storage layer 150 (or the gate 160), the resistance of the channel 120a increases. Thus, the electrochemical storage cell can be switched to a high-resistance state, i.e., the reset state.

[0064] In an embodiment, the electrochemical storage cell can be written to a low-resistance state and a high-resistance state by the exchange of oxygen vacancies and oxygen ions, but other embodiments are not limited thereto. Alternatively, the electrochemical storage cell can use hydrogen ions or lithium ions as the ions used in the storage operation.

[0065] Figure 4A and Figure 4B are cross-sectional views showing a read operation of an electrochemical storage cell according to an embodiment of the present disclosure. Figure 4A and Figure 4B are cross-sectional views taken along the line II-II' in Figure 2 . The interface layer IF in Figure 4A and Figure 4B can use the electrolyte layer 140 and the ion storage layer 150.

[0066] Refer to Figure 1 , Figure 2 , Figure 3A , Figure 4A and Figure 4B, To measure the resistance of the channel 120a in the electrochemical storage unit, a voltage below the threshold voltage (e.g., approximately 0V) can be applied to the gate 160. The ground voltage can be applied to the source S. The read voltage Vread can be applied to the drain D. The read voltage Vread can generate a current from the drain D to the source S without changing the resistance of the channel 120a.

[0067] For example, as Figure 3A and 4A shown, after transferring the oxygen vacancies Vo in the ion storage layer 150 to the channel 120a by applying the set voltage Vset, when the read voltage Vread is applied to the drain D, since the resistance of the channel 120a decreases due to the increase in oxygen vacancies, the electrochemical storage unit can output a current higher than the reference current. Therefore, the channel 120a can have a low resistance state. In addition, the current can be determined as the set current Iset. For example, a sensing device (not shown) can read the set data of the electrochemical storage unit.

[0068] Referring to Figure 3B and Figure 4B , after transferring the oxygen vacancies Vo in the channel 120a to the ion storage layer 150 by applying the reset voltage Vreset, when the read voltage Vread is applied to the drain D, since the resistance of the channel 120a increases due to the decrease in oxygen vacancies Vo, the electrochemical storage unit can output a current lower than the reference current. Therefore, the channel 120a can have a high resistance state. In addition, the current can be determined as the reset current Ireset. For example, a sensing device (not shown) can read the reset data of the electrochemical storage unit.

[0069] Figure 5 is a graph showing the conductance G of the storage unit according to an embodiment of the present disclosure, Figure 6 is a graph showing the change ΔG in the conductance G of the storage unit.

[0070] Referring to Figure 5 , under the same conditions, an operating voltage such as a programming voltage can be applied to the gate of the 3D electrochemical storage unit (a) with a fin-shaped channel and the gate of the 2D electrochemical storage unit (b) with a planar channel of the exemplary embodiment.

[0071] In an embodiment, the ions used for the storage operation can be transferred to the channel of the 3D electrochemical storage unit (a) through the protruding surface of the fin-shaped channel overlapping with the gate. In some embodiments, the fin-shaped channel of the 3D electrochemical storage unit (a) can be smaller than the planar channel of the 2D electrochemical storage unit (b). Therefore, the electrochemical reaction in the channel of the disclosed embodiment can occur faster than the electrochemical reaction in the planar channel of the 2D electrochemical storage unit (b).

[0072] Thus, it can be noted that the conductance G of the 3D electrochemical storage cell (a) with fin-shaped channels disclosed herein can change at a greater rate than the conductance G of the 2D electrochemical storage cell (b) with planar channels.

[0073] That is, after a time T1, it can be noted that the conductance G of the 3D electrochemical storage cell (a) can increase significantly compared to the conductance G of the 2D electrochemical storage cell (b).

[0074] Therefore, when the same programming voltage is applied over the same time period, it can be noted that the set / reset ratio (on / off efficiency) of the 3D electrochemical storage cell (a) is improved compared to that of the 2D electrochemical storage cell (b).

[0075] In addition, as Figure 5 shown, the 3D electrochemical storage cell (a) can reach the maximum conductance G1 of the 2D electrochemical storage cell (b) at a time T0, which is shorter than the time T1 for the 2D electrochemical storage cell (b) to reach the maximum conductance G1. Therefore, the 3D electrochemical storage cell (a) can have a faster operation speed than the 2D electrochemical storage cell (b). As a result, the 3D electrochemical storage cell (a) of the exemplary embodiment can be driven by a smaller amount of power.

[0076] As Figure 6 shown, the change ΔG in the conductance G in the 3D electrochemical storage cell (c) of the embodiment can change rapidly compared to the change ΔG in the conductance G of the 2D electrochemical storage cell (d). Therefore, the 3D electrochemical storage cell (c) can have a faster operation speed than the 2D electrochemical storage cell (d).

[0077] In some embodiments, the storage cells of the neural network storage device can use electrochemical storage cells with 3D channels having fin-shaped or fin-like shapes. The channels with fin-shaped can be 3D protrusion shapes and smaller than the size of the planar channels of the 2D electrochemical storage cells. Therefore, ions for storage operations can be exchanged with each other through the entire outer surface of the channels with fin-shaped, so that the resistance change of the channels with fin-shaped can be generated rapidly in a short time. In this way, the on / off ratio of the fin-shaped channels can be greatly improved, thereby improving the verification efficiency.

[0078] In addition, compared to the 2D planar channels, the channels with fin-shaped can have the size and space of 3D protrusions, thereby generating various conductance changes.

[0079] Therefore, in order to induce a conductance substantially the same as that of the 2D electrochemical storage cell, a lower programming voltage can be used. Thus, the electrochemical storage cell of the exemplary embodiment can have a relatively low voltage drive and low power consumption.

[0080] In addition, as Figure 6 shown, compared with the 2D electrochemical storage cell, ion exchange can be performed through the protruding surface in the limited space of the 3D electrochemical storage cell to improve the operation speed.

[0081] That is, in the 2D electrochemical storage cell, the reaction direction and diffusion direction of ions can be fixed to be substantially perpendicular to the direction of the channel. In contrast, in the 3D electrochemical storage cell, ions can transfer and diffuse along the horizontal direction, the vertical direction, and the angled direction between horizontal and vertical to cause a rapid resistance change.

[0082] In addition, the fin-shaped channel of the 3D protrusion can serve to reduce the occupied area of the storage cell to improve the integration density of the storage device.

[0083] The above embodiments of the present invention are intended to illustrate rather than limit the present invention. Various alternatives and equivalent schemes are possible. The present invention is not limited to the embodiments described herein. The present invention is also not limited to any specific type of semiconductor device. Given this disclosure, other additions, subtractions, or modifications are obvious and are intended to fall within the scope of the appended claims.

Claims

1. An electrochemical storage unit comprising: an electrochemical channel comprising a fin-shaped protrusion having a protruding surface; a gate, which overlaps with the fin-shaped protrusion; as well as An interface layer is located between the protrusion surface and the gate, and the interface layer exchanges ions between the gate and the electrochemical channel in a storage operation with a gate voltage applied.

2. The electrochemical storage cell according to claim 1, wherein: The interface layer includes an electrolyte layer covering a surface of the protrusion.

3. The electrochemical storage cell according to claim 2, wherein: The interface layer further includes an ion storage layer between the electrolyte layer and the gate, the ion storage layer generating and receiving the ions based on the gate voltage.

4. The electrochemical storage cell according to claim 3, wherein: The electrolyte layer includes an insulating material.

5. The electrochemical storage cell according to claim 3, wherein: The ion storage layer includes an ion component and a metal component.

6. The electrochemical storage cell according to claim 1, further comprising: A fin-shaped source electrode formed on one side of the electrochemical channel; as well as A fin-shaped drain is formed on the other side of the electrochemical channel.

7. The electrochemical storage cell according to claim 1, wherein: At least one of the electrochemical channel, the gate, and the interface layer includes a material that undergoes an electrochemical reaction based on the gate voltage.

8. An electrochemical storage unit comprising: an electrochemical fin structure, which protrudes from the underlying layer; a gate overlapping a channel of the electrochemical fin structure; a source electrode formed in the electrochemical fin structure on one side of the gate; a drain formed in the electrochemical fin structure on the other side of the gate; an electrolyte layer, located between the channel and the gate, and in contact with the sidewall and upper surface of the channel; as well as an ion storage layer, located between the electrolyte layer and the gate, generating and receiving ions based on a gate voltage, The electrolyte layer selectively provides the ions to the channel through the sidewalls and the upper surface of the channel based on the gate voltage.

9. The electrochemical storage cell according to claim 8, wherein: The electrolyte layer includes an insulating material.

10. The electrochemical storage cell according to claim 8, wherein: The ion storage layer includes an ion component and a metal component.

11. The electrochemical storage cell according to claim 8, wherein: At least one of the channel, the gate, the electrolyte layer, and the ion storage layer includes a material that undergoes an electrochemical reaction based on the gate voltage.

12. The electrochemical storage cell according to claim 8, wherein: At least one of the ion storage layer and the gate overlaps the sidewall and the upper surface of the channel.

13. A neural network storage device, comprising: a plurality of word lines extending parallel to each other along a first direction; a plurality of bit lines extending parallel to each other along a second direction intersecting the first direction; a plurality of source lines extending parallel to at least one of the first direction and the second direction; as well as an electrochemical storage unit arranged at the intersection of the word line, the bit line and the source line, Wherein, the electrochemical storage unit comprises: Protruding electrochemical fin structure; a gate overlapping a channel region of the protruding electrochemical fin structure and electrically connected to any one of the plurality of word lines; a source electrode formed in the protruding electrochemical fin structure at one side of the gate and electrically connected to any one of the plurality of source lines; a drain formed in the protruding electrochemical fin structure at the other side of the gate and electrically connected to any one of the plurality of bit lines; and An electrolyte layer is located between the channel region and the gate and is in contact with both the sidewall and the upper surface of the channel region.

14. The neural network memory device according to claim 13, further comprising an ion storage layer which is interposed between the electrolyte layer and the gate and generates and receives ions based on a gate voltage.

15. The neural network storage device according to claim 14, wherein: At least one of the ion storage layer and the gate overlaps a sidewall and the upper surface of the channel region.

16. The neural network storage device according to claim 13, wherein: The electrolyte layer includes an insulating material.

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