Transistor based on cation transverse motion and preparation and control method thereof
Technical Field
The invention relates to the field of artificial synapse transistors, in particular to a transistor based on cation lateral motion and a preparation method and a control method thereof.
Background
The traditional computer is based on the micro-processing chip technology of a von Neumann computer architecture, and is characterized in that information storage and information processing are separated from calculation, and as information expands, people enter an artificial intelligence era. The traditional computer can not process complex information in real time with small power consumption like the brain, and has powerful learning, memorizing and parallel computing functions. Therefore, the study of human brain or brain-like computing has become a focus of research in the scientific community in recent years. Most of current researches are only focused on simulating and simulating the large-scale neural network of the human brain, the adopted simulated neural network chip is still based on the traditional CMOS process technology, even the integration level of the chip is further improved, the chip still stays in the original computer framework, data disappear after power failure, the bionic memory function cannot be realized, and the gap with the human brain is large.
Various emerging ideas and components are proposed to emulate neuronal and inter-neuronal synaptosomal nodes, including an ionic liquid-based artificial synapse transistor. In the ionic liquid synaptic transistor, short-term memory and long-term memory of human brain can be simulated. These functions are the basis for operation, learning and memory of the neuron system, but the simulation of the pulse signals transmitted and received between neurons to realize the operation and analysis of the human brain requires not only the artificial synapse transistor to simulate the memory function of the human brain, but also the switching, excitation and inhibition, parallel computation and the like of the nerve-like function, and at present, no such ionic liquid artificial synapse transistor can integrate the above functions.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a transistor based on lateral movement of cations, which can simulate not only the short-term and long-term memory functions of the human brain but also the switching and suppression functions of the human brain.
The purpose of the invention is realized by the following technical scheme: a transistor based on cation lateral movement comprises an insulating substrate, a bottom gate electrode layer, a metal oxide layer, a source electrode layer, a drain electrode layer, a top gate electrode layer and an electrolyte layer; the bottom gate electrode layer is arranged on the surface of the insulating substrate; the metal oxide layer covers the surface of the bottom gate electrode layer, and two side areas exposed out of the surface of the bottom gate electrode layer are not covered and are used for being connected with an external circuit to generate transverse current in the bottom gate electrode layer; the source electrode layer and the drain electrode layer are respectively arranged at two opposite ends of one side of the surface of the metal oxide layer and are not in contact with each other, a conductive channel is formed in an area between the source electrode layer and the drain electrode layer, and the direction of the conductive channel is not parallel to the direction of the transverse current; the top gate electrode layer is arranged on the other side of the surface of the metal oxide layer and is not in contact with the source electrode layer and the drain electrode layer; the electrolyte layer is an electrolyte layer containing cations, is arranged on the surface of the metal oxide layer, is in contact with the top gate electrode layer, and is not in contact with the source electrode layer and the drain electrode layer.
Compared with the prior art, the invention can apply voltage between the top gate electrode layer and the bottom gate electrode layer, thereby injecting positive ions in the electrolyte layer into the metal oxide layer, and the resistance of the conductive channel is reduced along with the increase of the applied voltage, and the process can simulate the short-term and long-term memory functions of the human brain; meanwhile, transverse current can be introduced into the bottom gate electrode layer, a magnetic field is formed between the interface of the electrolyte layer and the metal oxide layer by the transverse current, cations in the conducting channel can migrate to one side, far away from the conducting channel, of the metal oxide layer along the current direction under the action of the magnetic field, so that the resistance of the conducting channel is increased, and the process can simulate the switching and inhibiting functions in human brain-like calculation.
Further, the direction of the conductive channel is perpendicular to the direction of the lateral current flow.
Further, in the direction along the conductive channel, the length of the metal oxide layer is greater than the width of the bottom gate electrode layer, and the length of the conductive channel is less than the width of the bottom gate electrode layer.
Go toStep (b), the metal oxide layer is WO3Film or MoO3The film has a thickness of 100 to 800 nm.
Further, the cation is a lithium ion or a hydrogen ion.
The invention also provides a preparation method of the transistor based on the cation transverse motion, which comprises the following steps:
s1: depositing a bottom gate electrode layer on the surface of the insulating substrate;
s2: depositing a metal oxide layer on the surface of the bottom gate electrode layer, covering the metal oxide layer on the surface of the bottom gate electrode layer, wherein two side areas exposed out of the surface of the bottom gate electrode layer are not covered and are used for being connected with an external circuit to generate transverse current in the bottom gate electrode layer;
s3: depositing a source electrode layer and a drain electrode layer at two opposite ends of one side of the surface of the metal oxide layer respectively to ensure that the source electrode layer and the drain electrode layer are not contacted with each other, forming a conductive channel in an area between the source electrode layer and the drain electrode layer, wherein the direction of the conductive channel is not parallel to the direction of the transverse current;
s4: depositing a top gate electrode layer on the other side of the surface of the metal oxide layer, so that the top gate electrode layer is not in contact with the source electrode layer and the drain electrode layer;
s5: and spin-coating an electrolyte layer containing cations on the surface of the metal oxide layer, so that the electrolyte layer is in contact with the top gate electrode layer and is not in contact with the source electrode layer and the drain electrode layer.
The invention also provides a control method of the transistor based on the cation transverse motion, which comprises the following steps:
w1: loading voltage between the top gate electrode layer and the bottom gate electrode layer to inject cations in the electrolyte layer into the metal oxide layer, so that the resistance value of a conductive channel between the source electrode layer and the drain electrode layer is reduced, and the transistor is in an open state; removing the voltage loaded between the top gate electrode layer and the bottom gate electrode layer, and temporarily and stably retaining the injected cations in the metal oxide layer;
w2: introducing transverse current vertical to the conducting channel into the bottom gate electrode layer, so that cations staying in the conducting channel migrate along the current direction and are gathered to one side, away from the conducting channel, of the metal oxide layer, the resistance value of the conducting channel is increased, and the transistor is in a closed state;
w3: the lateral current in the bottom gate electrode layer is removed, causing the cations to re-enter the conduction channel in a self-diffusing manner, causing the resistance of the conduction channel to drop and the transistor to be in an on state.
Further, the amount of cations injected from the electrolyte layer to the metal oxide layer is controlled by controlling the time for which the voltage is applied; the resistance value of the conductive channel is inversely proportional to the number of cations residing in the conductive channel.
Further, the cations injected into the metal oxide layer spontaneously escape into the electrolyte layer after staying for a sufficient time.
Further, the magnitude of the transverse current is 0.05-0.2A.
For a better understanding and practice, the invention is described in detail below with reference to the accompanying drawings.
Drawings
Fig. 1 is a schematic structural view of a transistor based on lateral motion of cations according to example 1.
Fig. 2 is a transistor output characteristic curve under the control of the top gate electrode layer applied voltage of example 1.
Fig. 3 is a graph showing the output characteristics of the transistor under the control of the bottom gate electrode layer lateral current in example 1.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Example 1
Please refer to fig. 1, which is a schematic structural diagram of a transistor based on lateral movement of cations according to the present embodiment. The transistor based on the lateral movement of cations comprises an insulating substrate 1, a bottom gate electrode layer 3, a metal oxide layer 2, a source electrode layer 5, a drain electrode layer 6, a top gate electrode layer 4 and an electrolyte layer 7.
The bottom gate electrode layer 3 is disposed on the surface of the insulating substrate 1, in this embodiment, the bottom gate electrode layer 3 covers the middle portion of the insulating substrate 1, the area of the bottom gate electrode layer is smaller than that of the insulating substrate 1, and an area not covered by the bottom gate electrode layer 3 is exposed in the longitudinal direction of the insulating substrate 1. The insulating substrate 1 may be a glass substrate, and the bottom gate electrode layer 3 may be a metal conductive layer.
The metal oxide layer 2 covers the surface of the bottom gate electrode layer 3, and two side areas exposed out of the surface of the bottom gate electrode layer 3 are not covered and are used for being connected with an external circuit to generate transverse current in the bottom gate electrode layer 3. In this embodiment, the length of the metal oxide layer 2 in the lateral direction is smaller than the length of the bottom gate electrode layer 3 in the lateral direction, so that the left and right sides of the bottom gate electrode layer 3 are exposed and not covered. The length of the metal oxide layer 2 in the longitudinal direction is greater than the length of the bottom gate electrode layer 3 in the longitudinal direction, and a portion thereof exceeding the length of the bottom gate electrode layer 3 is in contact with the insulating substrate 1. The metal oxide layer 2 may be a metal oxide thin film, preferably WO3Film or MoO3The film preferably has a thickness of 100 to 800 nm.
The source electrode layer 5 and the drain electrode layer 6 are respectively arranged at two opposite ends of one side of the surface of the metal oxide layer 2, and are not in contact with each other, and a conductive channel is formed in the region between the two. In this embodiment, the source electrode layer 5 and the drain electrode layer 6 are respectively disposed at two longitudinal ends of the left side of the surface of the metal oxide layer 2, and the edges thereof extend to the outside of the metal oxide layer 2, but do not contact with the insulating substrate 1. The conductive channel between the source electrode layer 5 and the drain electrode layer 6 is along the longitudinal direction, and the length of the conductive channel is smaller than the longitudinal width of the bottom gate electrode layer 3, so that the conductive channel is completely positioned above the bottom gate electrode layer 3 to receive the transverse current drive in the bottom gate electrode layer 3.
The top gate electrode layer 4 is disposed on the other side of the surface of the metal oxide layer 2, and is not in contact with the source electrode layer 5 and the drain electrode layer 6. In this embodiment, the top gate electrode layer 4 is disposed above the right side of the surface of the metal oxide layer 2.
The electrolyte layer 7 is a cation-containing electrolyte layer, is provided on the surface of the metal oxide layer 2, is in contact with the top gate electrode layer 4, and is not in contact with the source electrode layer 5 and the drain electrode layer 6. In this embodiment, the electrolyte may be a liquid electrolyte, a gel electrolyte or a solid electrolyte, and the cation is preferably lithium ion or hydrogen ion.
The preparation method of the transistor based on the lateral movement of the cations comprises the following steps:
(1) and depositing a metal conductive layer on the non-conductive glass substrate to serve as a bottom gate electrode layer.
(2) Longitudinally depositing a metal oxide layer on the bottom gate electrode layer by masking (WO)3And the thin film spans the bottom gate electrode layer, so that the metal oxide layer covers the middle area of the surface of the bottom gate electrode layer, and the two side areas exposed out of the surface of the bottom gate electrode layer are not covered and are used for being connected with an external circuit to generate transverse current in the bottom gate electrode layer.
(3) And respectively depositing a source electrode layer and a drain electrode layer at two opposite ends of the left side of the surface of the metal oxide layer, so that the source electrode layer and the drain electrode layer are not contacted with each other, forming a longitudinal conductive channel in the region between the source electrode layer and the drain electrode layer, wherein the direction of the conductive channel is vertical to the direction of the transverse current.
(4) And depositing a top gate electrode layer on the right side of the surface of the metal oxide layer through magnetron sputtering, so that the top gate electrode layer is not in contact with the source electrode layer and the drain electrode layer.
(5) Spin coating a colloid electrolyte layer (PC-LiClO) containing cations on the surface of the metal oxide layer4) And contacting the electrolyte layer with the top gate electrode layer and not with the source electrode layer and the drain electrode layer.
The control method of the transistor based on the lateral movement of the positive ions comprises the following steps:
(1) loading voltage between the top gate electrode layer and the bottom gate electrode layer to inject cations in the electrolyte layer into the metal oxide layer, so that the resistance value of a conductive channel between the source electrode layer and the drain electrode layer is reduced, and the transistor is in an open state; and removing the voltage loaded between the top gate electrode layer and the bottom gate electrode layer, and temporarily and stably retaining the injected cations in the metal oxide layer. The amount of cations injected from the electrolyte layer to the metal oxide layer can be controlled by controlling the time for which the voltage is applied, and the resistance value of the conductive channel is inversely proportional to the amount of cations residing in the conductive channel.
(2) And introducing transverse current vertical to the conducting channel into the bottom gate electrode layer, so that cations staying in the conducting channel migrate along the current direction and are gathered to one side of the metal oxide layer far away from the conducting channel, the resistance value of the conducting channel is increased, and the transistor is in an off state. The magnitude of the transverse current is preferably 0.05-0.2A.
(3) The lateral current in the bottom gate electrode layer is removed, causing the cations to re-enter the conduction channel in a self-diffusing manner, causing the resistance of the conduction channel to drop and the transistor to be in an on state. The cations injected into the metal oxide layer spontaneously escape into the electrolyte layer after staying for a sufficient period of time.
Please refer to fig. 2, which is a characteristic curve of the output of the transistor under the control of the top gate electrode loading voltage in the present embodiment. Under the condition that the bottom gate electrode layer is grounded, voltages (0-3V) with different magnitudes are applied to the top gate electrode layer for 10s, and after the voltage of the top gate electrode layer is removed, an I-V characteristic curve between the source electrode layer and the drain electrode layer in the device is tested, as shown in FIG. 2. It can be seen that as the applied voltage increases, the resistance of the conduction channel between the source and drain electrode layers decreases, because the number of cations injected into the conduction channel from the electrolyte layer increases, resulting in a decrease in the resistance of the conduction channel. The process can simulate the memory function of the human brain under different external stimuli, and when the stimuli applied in the learning process are larger, the relevance and the memory between two neurons are stronger.
Please refer to fig. 3, which is a characteristic curve of the transistor output under the control of the bottom gate electrode layer lateral current in the present embodiment. Firstly, applying a voltage of 3V on the top gate electrode layer for 60s, then removing the voltage of the top gate electrode layer, introducing transverse currents (0-0.2A) with different sizes into the bottom gate electrode layer, forming a magnetic field between the electrolyte layer and the metal oxide layer by the transverse currents, and enabling ions in the conductive channel to migrate along the current direction and gather to the other side of the metal oxide layer far away from the conductive channel under the action of the magnetic field, so that the resistance of the conductive channel is rapidly increased, and finally the source electrode layer and the drain electrode layer are in an off state. This process can simulate the on-off switching and suppression functions in human-like brain computing.
Compared with the prior art, the transistor based on the cation transverse motion can simulate the short-term and long-term memory function of the human brain, can also simulate the switch switching and inhibiting functions of the human brain, and has better application prospect.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.