An artificial synapse device of perovskite and metal oxide composite structure

Abstract

The utility model provides a kind of perovskite and metal oxide composite structure artificial synapse device, including high doped silicon layer, silicon oxide layer, perovskite film and metal oxide film, the top of high doped silicon layer is provided with silicon oxide layer, the top of silicon oxide layer is provided with perovskite film, the top of perovskite film is provided with metal oxide film.The utility model changes device structure to realize the function of artificial synapse, makes device to appear counterclockwise hysteresis when being bidirectional transmission characteristic curve test, and output current shows memory function when being pulse test.Through depositing perovskite film first, subsequently depositing metal oxide film on perovskite film, avoid the direct contact of perovskite film and air, so that device has better stability and life.The preparation method of the utility model only includes spin coating, magnetron sputtering and thermal evaporation, and operation process is simpler, process is compatible simultaneously, and time cost and process cost are lower.

Description

Technical Field

[0001] This utility model relates to an artificial synapse device, and more particularly to an artificial synapse device with a perovskite and metal oxide composite structure, belonging to the field of semiconductor technology. Background Technology

[0002] Artificial synaptic devices primarily stem from the need for neuromorphic computing and neuro-inspired computing, aiming to simulate the synaptic function in biological nervous systems to achieve efficient, low-power information processing. Common metal-oxide semiconductors include indium oxide, zinc oxide, and indium gallium zinc oxide, which belong to the n-type semiconductor category. These semiconductors are widely used due to their high carrier mobility and reliability, but their response to light is limited, typically referring to their response to ultraviolet light. Therefore, perovskite materials, due to their unique crystal structure and excellent optoelectronic properties, have been frequently used in recent years to extend the optoelectronic synergistic modulation of metal-oxide field-effect thin-film transistors. The combination of these two material systems ensures both the high carrier mobility of artificial photoelectric synapses and broadens their application in various scenarios. Artificial synaptic devices mainly simulate the storage function in neuronal cells. For devices using n-type semiconductors as channels, the transmission characteristic curve of the device needs to exhibit counterclockwise hysteresis when facing bidirectional scanning, essentially a reduction in the threshold voltage. This hysteresis is to demonstrate that after applying a voltage once, only a smaller voltage is needed to achieve the same current the second time, simulating the learning process in neuronal cells.

[0003] Currently, the combination of these two material systems is mostly used in photodetectors, aiming to utilize the broad absorption spectrum of perovskite materials. Typically, the combination involves spin-coating the perovskite material onto the surface of a metal oxide film as a photosensitive layer. The working mechanism of this method is that when light shines on the photosensitive layer, photogenerated carriers are generated. Under the readout voltage, electron-hole pairs separate, thus enabling the device's response to light. In addition, the combination of these two material systems can also be achieved by fabricating floating-gate transistors, using perovskite as the floating gate layer, a high-k dielectric as the tunneling layer, and a metal oxide semiconductor as the channel. This method aims to utilize the charge trapping and detrapping capabilities of the floating gate layer to achieve storage functionality. This method has certain drawbacks. First, it cannot guarantee the stability of the perovskite film, leading to the failure of the photosensitive layer. Second, traditional thin-film transistors using metal oxide films as the channel layer exhibit clockwise hysteresis when bidirectionally scanning the transmission characteristic curve, preventing the thin-film transistor from functioning as an artificial synapse. Finally, this method requires the fabrication of a very thin tunneling layer, typically less than 10 nm, necessitating atomic layer deposition (ALD) to achieve high-quality deposition of high-k materials. Furthermore, high-k materials require high-temperature processes, which can easily lead to the failure of the perovskite layer. In addition, this method is time-consuming, and ALD equipment is expensive, resulting in low cost-effectiveness. Therefore, a perovskite and metal oxide composite artificial synapse device is proposed. Utility Model Content

[0004] In view of this, the present invention provides an artificial synapse device with a perovskite and metal oxide composite structure to solve or alleviate one of the technical problems existing in the prior art, and at least provides a beneficial alternative.

[0005] The technical solution of this utility model embodiment is implemented as follows: an artificial synapse device with a perovskite and metal oxide composite structure includes a highly silicon-doped layer, a silicon oxide layer, a perovskite thin film and a metal oxide thin film. A silicon oxide layer is disposed on top of the highly silicon-doped layer, a perovskite thin film is disposed on top of the silicon oxide layer, a metal oxide thin film is disposed on top of the perovskite thin film, and a drain and a source are disposed on top of the metal oxide thin film.

[0006] A further preferred embodiment is that the highly silicon-doped layer is the gate of an artificial synaptic device with a perovskite and metal oxide composite structure.

[0007] A further preferred embodiment is that the silicon oxide layer is the dielectric layer of an artificial synaptic device with a perovskite and metal oxide composite structure.

[0008] A further preferred embodiment: the perovskite film is deposited on the surface of the silicon oxide layer using a spin coater.

[0009] A further preferred embodiment: the metal oxide film is deposited on the surface of the perovskite film using a magnetron sputtering device.

[0010] A further preferred embodiment: the source and drain electrodes are deposited on the surface of a metal oxide thin film using a thermal evaporation device.

[0011] A further preferred embodiment is that the thickness of the metal oxide film is 20 nm.

[0012] A further preferred embodiment: the thickness of the source and drain electrodes is 120 nm.

[0013] The present invention has the following advantages due to the adoption of the above technical solution: I. This utility model changes the structure of a semiconductor device utilizing perovskite and metal oxides. By changing the device structure, it realizes the function of artificial synapses, causing the device to exhibit counterclockwise hysteresis (also known as a memory window) when performing bidirectional transmission characteristic curve tests, and the output current exhibits memory function during pulse testing.

[0014] Second, by first depositing a perovskite thin film and then depositing a metal oxide thin film on the perovskite thin film, this utility model avoids direct contact between the perovskite thin film and the air, thus giving the device better stability and lifespan.

[0015] Third, the preparation method of this utility model only includes spin coating, magnetron sputtering and thermal evaporation, which makes the operation process simpler, the processes are compatible at the same time, and the time and process costs are lower.

[0016] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the present invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a front view of the present invention. Figure 2 This is a structural diagram of the present invention; Figure 3 This is a comparison chart of the transmission characteristic curves of this utility model; Figure 4 This is a comparison chart of the memory performance test results of this utility model.

[0019] Figure reference numerals: 11, highly doped silicon layer; 12, silicon oxide layer; 13, perovskite thin film; 14, metal oxide thin film; 15, drain electrode; 16, source electrode. Detailed Implementation

[0020] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0021] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0022] like Figures 1-4 As shown, this embodiment of the present invention provides an artificial synapse device with a perovskite and metal oxide composite structure, including a highly silicon-doped layer 11, a silicon oxide layer 12, a perovskite thin film 13, and a metal oxide thin film 14. The silicon oxide layer 12 is disposed on the top of the highly silicon-doped layer 11, the perovskite thin film 13 is disposed on the top of the silicon oxide layer 12, the metal oxide thin film 14 is disposed on the top of the perovskite thin film 13, and the drain electrode 15 and the source electrode 16 are disposed on the top of the metal oxide thin film 14.

[0023] In this embodiment, specifically: the highly silicon-doped layer 11 is the gate of an artificial synapse device with a perovskite and metal oxide composite structure, and a silicon wafer with an oxide layer is used as the substrate, wherein the highly silicon-doped layer 11 serves as the gate of the device and the silicon oxide layer 12 serves as the dielectric layer of the device.

[0024] In this embodiment, specifically: the silicon oxide layer 12 is the dielectric layer of an artificial synaptic device with a perovskite and metal oxide composite structure.

[0025] In this embodiment, specifically: the perovskite film 13 is deposited on the surface of the silicon oxide layer 12 using a spin coater. The deposition of the perovskite layer needs to be carried out in a glove box to avoid contamination of the perovskite film 13.

[0026] In this embodiment, specifically: the metal oxide film 14 is deposited on the surface of the perovskite film 13 by a magnetron sputtering device. The perovskite film 13 is deposited first, and then the metal oxide film 14 is deposited on the perovskite film 13. This avoids direct contact between the perovskite film 13 and the air, resulting in better stability and lifespan of the device.

[0027] In this embodiment, specifically: the drain 15 and the source 16 are deposited on the surface of the metal oxide thin film 14 by a thermal evaporation device. When the drain 15 and the source 16 are deposited, the substrate is attached to the mask, and then the thermal evaporation operation is performed.

[0028] In this embodiment, specifically, the thickness of the metal oxide thin film 14 is 20 nm.

[0029] In this embodiment, specifically, the thickness of the drain 15 and the source 16 is 120nm.

[0030] In the production process of this invention: First, the substrate is cleaned by ultrasonically treating it in deionized water for 15 minutes to remove inorganic contaminants from the surface. Then, the substrate is ultrasonically treated in anhydrous ethanol for 15 minutes to remove organic contaminants. Next, the substrate is ultrasonically treated in deionized water for 15 minutes to clean any remaining anhydrous ethanol solution from the substrate surface. Finally, the substrate is ultrasonically treated in deionized water for 5 minutes to ensure all residual anhydrous ethanol is removed. Next, the perovskite layer is deposited. First, the cleaned substrate is placed on a spin coater. Then, 3-5 drops of the perovskite precursor solution are dropped into the center of the substrate, followed by low-speed spin coating at 200 rpm for 5 seconds. Then, high-speed spin coating at 2000 rpm for 20 seconds is performed. This process is repeated, followed by annealing at 120 degrees Celsius for 10 minutes, and then deposition of the metal oxide thin film 14. This step first requires fixing the deposited perovskite thin film 13 into a magnetron sputtering device. First, the vacuum level of the magnetron sputtering equipment is evacuated to below 6E-4 Pa. Then, the required sputtering gases are introduced, with an argon to oxygen flow rate ratio of 40 sccm:10 sccm. The operating pressure inside the equipment is then adjusted to 0.65 Pa, and the sputtering power is set to 60 W. Next, the desired metal oxide semiconductor target is selected, and pre-sputtering is performed, typically requiring 10 minutes to ensure proper sputtering. After pre-sputtering, the final sputtering is performed, controlling the final metal oxide film thickness (14) to be 20 nm, with a sputtering rate of 0.25 A / s. After sputtering, the vacuum level is restored to atmospheric pressure, the substrate is removed, and then source (16) and drain (15) deposition is performed. For the thermal evaporation equipment, the vacuum level is first evaporated to below 6E-4 Pa, then evaporation is started, adjusting the power to reach the metal melting temperature. Pre-evaporation is performed first, and after the evaporation rate stabilizes, the sample baffle is opened for final evaporation. The evaporation rate is controlled at 2.5 A / s, and the deposition thickness is 120 nm.

[0031] like Figure 1 As shown, this proposal differs from previous ones by attaching a metal oxide thin film 14 above a perovskite thin film 13. This structure not only leverages the wide-band absorption characteristics of perovskite materials but also allows for the manipulation of charge carriers in the channel using the perovskite thin film 13. When the device is tested, the built-in electric field in the perovskite material induces ion migration, resulting in charge trapping and detrapping. This changes the clockwise hysteresis present in traditional metal oxide thin film transistors when facing bidirectional gate voltage scanning to counterclockwise hysteresis. This change enables the thin film transistor device to possess storage capabilities, mimicking the function of artificial synapses. The effect is as follows: Figure 2 , Figure 3 As shown.

[0032] Example 2 In the production process of this invention, the trench layer can be deposited by means of an aqueous solution method instead of magnetron sputtering.

[0033] The aqueous solution method is faster and cheaper than magnetron sputtering, but it also has process compatibility issues. The channel layer deposited by the aqueous solution method requires annealing at a certain temperature, which can easily cause the perovskite film 13 to fail. At the same time, the film thickness deposited by the aqueous solution method is relatively rough and the long-term stability is also worse.

[0034] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An artificial synaptic device with a perovskite and metal oxide composite structure, comprising a highly silicon-doped layer (11), a silicon oxide layer (12), a perovskite thin film (13), and a metal oxide thin film (14), characterized in that: A silicon oxide layer (12) is disposed on top of the highly silicon-doped layer (11), a perovskite thin film (13) is disposed on top of the silicon oxide layer (12), a metal oxide thin film (14) is disposed on top of the perovskite thin film (13), and a drain (15) and a source (16) are disposed on top of the metal oxide thin film (14); the metal oxide thin film (14) is deposited on the surface of the perovskite thin film (13) by a magnetron sputtering device.

2. The artificial synaptic device with a perovskite and metal oxide composite structure according to claim 1, characterized in that: The highly silicon-doped layer (11) is the gate of an artificial synaptic device with a perovskite and metal oxide composite structure.

3. The artificial synaptic device with a perovskite and metal oxide composite structure according to claim 1, characterized in that: The silicon oxide layer (12) is the dielectric layer of an artificial synaptic device with a perovskite and metal oxide composite structure.

4. The artificial synaptic device with a perovskite and metal oxide composite structure according to claim 1, characterized in that: The perovskite film (13) is deposited on the surface of the silicon oxide layer (12) by a spin coater.

5. The artificial synaptic device with a perovskite and metal oxide composite structure according to claim 1, characterized in that: The drain (15) and source (16) are deposited on the surface of a metal oxide thin film (14) using a thermal evaporation device.

6. The artificial synaptic device with a perovskite and metal oxide composite structure according to claim 1, characterized in that: The thickness of the metal oxide thin film (14) is 20 nm.

7. The artificial synaptic device with a perovskite and metal oxide composite structure according to claim 1, characterized in that: The thickness of the drain (15) and source (16) is 120 nm.

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