Photoelectric memristor based on amorphous gallium oxide and preparation method thereof

Abstract

The invention discloses a photoelectric memristor based on amorphous gallium oxide and a preparation method thereof, the photoelectric memristor comprises a top electrode (1), a functional layer (2), a bottom electrode (3) and a substrate (4) which are sequentially arranged from top to bottom, the top electrode (1) adopts a transparent electrode, the functional layer (2) is an amorphous Ga2O3 film, and the bottom electrode (3) adopts an inert electrode. The photoelectric memristor provided by the invention can realize long-term enhancement and long-term inhibition of synapses under the condition of deep ultraviolet illumination, and shows continuously adjustable synaptic plasticity. The photoelectric memristor has short-term memory and long-term memory behaviors, and short-term memory can be converted into long-term memory after multiple times of short-time light pulse stimulation. The method is simple in preparation process and low in cost, and can be applied to construction of a bionic human vision system and a memory system.

Description

Technical Field

[0001] The invention relates to a photoelectric memristor based on amorphous gallium oxide and a preparation method thereof, belonging to the technical field of microelectronic devices. Background Art

[0002] In recent years, as the development of CMOS technology has been challenged by physical limitations, storage-computing integrated technology has rapidly emerged and is seen as a potential alternative to traditional CMOS technology. Since HP developed an oxide-based resistive switch in 2008, resistive memory has attracted much attention due to its advantages such as non-volatility, low power consumption, high density, low cost and fast read and write speed, and is considered a strong candidate for the next generation of storage-computing integrated technology. Biological synapses have the characteristics of perception, memory and computing in one, and can efficiently process information and exhibit intelligent behavior. Therefore, simulating biological synapses to build an artificial neural system that integrates "sensing-storage-computing" is expected to solve the problems of data redundancy caused by traditional separate architectures and promote the development of artificial synaptic technology based on resistive memory. Gallium oxide (Ga2O3), as an emerging ultra-wide bandgap semiconductor oxide, is rich in oxygen vacancies and has excellent characteristics such as low on-resistance and high electron mobility, making it an ideal material for preparing resistive memory. In addition, gallium oxide is sensitive to deep ultraviolet light and has a good sustainable photoconductivity effect. The photodetectors developed by it have broad application prospects in military, biological, medical and other fields, providing the possibility of integrating resistive memory and photodetectors. Although the existing gallium oxide memristors have achieved low power consumption and high switching ratio performance, these studies have not fully utilized the special absorption characteristics of gallium oxide in the solar-blind band to realize the information storage of solar-blind ultraviolet images. Research and application in this area still need further exploration and development. Summary of the invention

[0003] The purpose of the present invention is to address the defects and shortcomings of the above-mentioned prior art and propose a photoelectric memristor based on amorphous gallium oxide and a preparation method thereof. The photoelectric memristor can achieve long-term enhancement and long-term inhibition of synapses under deep ultraviolet light conditions, present continuously adjustable synaptic plasticity, have short-term memory and long-term memory behaviors, and can convert short-term memory into long-term memory after multiple short-term light pulse stimulation.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a photoelectric memristor based on amorphous gallium oxide, the photoelectric memristor comprising a top electrode 1, a functional layer 2, a bottom electrode 3 and a substrate 4 arranged in sequence from top to bottom, the top electrode 1 is a transparent electrode, the functional layer 2 is an amorphous Ga2O3 thin film, and the bottom electrode 3 is an inert electrode.

[0005] Furthermore, the transparent electrode used in the top electrode 1 is one of ITO and AZO.

[0006] Furthermore, the thickness of the amorphous Ga2O3 film of the functional layer 2 is 30-200nm.

[0007] Furthermore, the inert electrode used in the bottom electrode 3 is one of gold, platinum, ruthenium, palladium, rhodium, osmium and iridium.

[0008] Furthermore, the substrate 4 is a SiO2 / Si substrate.

[0009] The present invention also provides a method for preparing a photoelectric memristor based on amorphous gallium oxide, the method comprising the following steps:

[0010] Step 1: Clean the SiO2 / Si substrate with acetone, alcohol, and deionized water in sequence, and blow dry with nitrogen;

[0011] Step 2: sputtering and depositing a bottom electrode 3 on a SiO2 / Si substrate;

[0012] Step 3: using a mask to cover a portion of the bottom electrode 3, and then preparing an amorphous gallium oxide film;

[0013] Step 4: Prepare a transparent electrode array on the amorphous gallium oxide film using a mask.

[0014] Furthermore, the conditions for preparing the bottom electrode 3 in step 2 are: vacuum degree 1.0-1.6 Pa, time 1-5 min.

[0015] Furthermore, the conditions for preparing the amorphous gallium oxide film in step 3 are: background vacuum degree 3.0×10 -4 Pa, argon flow rate is 20-30sccm, sputtering pressure is 0.8-1.2Pa, sputtering power is 60-90W, and sputtering time is 5-30min.

[0016] Furthermore, the conditions for preparing the transparent electrode in step 4 are: background vacuum degree 3.0×10 -4 Pa, argon flow rate is 20-30sccm, sputtering pressure is 0.8-1.2Pa, sputtering power is 50-80W, and sputtering time is 5-30min.

[0017] Beneficial effects:

[0018] 1. The photoelectric memristor of the present invention can achieve long-term potentiation and long-term inhibition of synapses under deep ultraviolet light, showing continuously adjustable synaptic plasticity.

[0019] 2. The photoelectric memristor of the present invention has short-term memory and long-term memory behaviors, and can convert short-term memory into long-term memory after multiple short-term light pulse stimulations.

[0020] 3. The preparation process of the present invention is simple and low in cost, and can be applied to construct bionic human visual system and memory system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The schematic diagram is a structural diagram of a photoelectric memristor based on amorphous gallium oxide according to the present invention.

[0022] Label description: 1-top electrode; 2-functional layer; 3-bottom electrode; 4-substrate.

[0023] Figure 2 This is a cross-sectional SEM image of a photoelectric memristor based on amorphous gallium oxide according to the present invention.

[0024] Figure 3 This is a memristor IV test curve diagram of a photoelectric memristor based on amorphous gallium oxide according to the present invention.

[0025] Figure 4 This is a graph showing the results of a single short-term memory test of a photoelectric memristor based on amorphous gallium oxide under different light intensities according to the present invention.

[0026] Figure 5 This is a diagram showing the results of multiple short-time memory tests of a photoelectric memristor based on amorphous gallium oxide under different light intensities according to the present invention.

[0027] Figure 6 This is a graph showing the results of a single long-term memory test of a photoelectric memristor based on amorphous gallium oxide according to the present invention.

[0028] Figure 7 This is a diagram showing the long-term memory test results of a photoelectric memristor based on amorphous gallium oxide according to the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, features and advantages of the present invention more obvious and understandable, the embodiments of the present invention are clearly and completely described below in conjunction with the specific implementation methods involved in the drawings of the specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, such as embodiments that only change the purpose without changing the basic principles involved in the claims, are within the scope of protection of the present invention.

[0030] like Figure 1 As shown, the present invention proposes a photoelectric memristor based on amorphous gallium oxide, which includes a top electrode 1, a functional layer 2, a bottom electrode 3 and a substrate 4 arranged in sequence from top to bottom, the top electrode 1 is a transparent electrode, the functional layer 2 is an amorphous Ga2O3 film, and the bottom electrode 3 is an inert electrode.

[0031] The transparent electrode used in the top electrode 1 of the present invention is one of ITO and AZO.

[0032] The thickness of the amorphous Ga2O3 film of the functional layer 2 of the present invention is 30-200nm.

[0033] The inert electrode used in the bottom electrode 3 of the present invention is one of gold, platinum, ruthenium, palladium, rhodium, osmium and iridium.

[0034] The substrate 4 of the present invention is a SiO2 / Si substrate.

[0035] The present invention also provides a method for preparing a photoelectric memristor based on amorphous gallium oxide, comprising the following steps:

[0036] Step 1: Clean the SiO2 / Si substrate with acetone, alcohol, and deionized water in sequence, and blow dry with nitrogen;

[0037] Step 2: sputtering and depositing a bottom electrode 3 on a SiO2 / Si substrate;

[0038] Step 3: using a mask to cover a portion of the bottom electrode 3, and then preparing an amorphous gallium oxide film;

[0039] Step 4: Prepare a transparent electrode array on the amorphous gallium oxide film using a mask.

[0040] The conditions for preparing the bottom electrode 3 in the above step 2 are: vacuum degree 1.0-1.6 Pa, time 1-5 min.

[0041] The conditions for preparing the amorphous gallium oxide film in step 3 are: background vacuum degree 3.0×10 -4 Pa, argon flow rate is 20-30sccm, sputtering pressure is 0.8-1.2Pa, sputtering power is 60-90W, and sputtering time is 5-30min.

[0042] The conditions for preparing the transparent electrode in step 4 are: background vacuum degree 3.0×10 -4 Pa, argon flow rate is 20-30sccm, sputtering pressure is 0.8-1.2Pa, sputtering power is 50-80W, and sputtering time is 5-30min.

[0043] Embodiment 1

[0044] In this embodiment 1, the preparation process of the photoelectric memristor based on amorphous gallium oxide is as follows:

[0045] Step 1: Use acetone, alcohol, and deionized water to ultrasonically clean the SiO2 / Si substrate for 10 minutes, and then blow dry with nitrogen;

[0046] Step 2: Place the SiO2 / Si substrate into a multi-target magnetron sputtering system, and sputter-deposit the bottom electrode 3Pt at a vacuum of 1.6 Pa for 2 min;

[0047] Step 3: After taking out the sample, use a mask to cover part of the bottom electrode 3, and then put it into the magnetron sputtering system to prepare an amorphous gallium oxide film, and draw the background vacuum to 3.0×10 -4 After Pa, the argon gas flow rate was adjusted to 24 sccm, and the gallium oxide film was prepared under the conditions of gas pressure of 1.0 Pa and sputtering power of 80 W for 10 min;

[0048] Step 4: Prepare an ITO transparent electrode array on the amorphous gallium oxide film through a 5×5 circular hole array mask, and also draw the background vacuum to 3.0×10 -4 Pa, adjust the argon flow rate to 24 sccm, and then prepare the ITO transparent electrode under the conditions of gas pressure of 1.0 Pa and sputtering power of 60 W, and the sputtering time is 10 min.

[0049] Figure 2 The cross-sectional SEM image of the photoelectric memristor prepared in Example 1 shows that there is an obvious boundary between each layer of the structure, and the thicknesses of the amorphous gallium oxide film and the ITO transparent electrode are approximately 50 nm and 100 nm, respectively.

[0050] like Figure 3 As shown, it is the memristor IV test curve of the photoelectric memristor prepared in this embodiment. After Forming, a scanning voltage of 0→5V→0→-2V→0 is applied, the step size is 0.1V, and the current is limited to 1mA. In process 1, the resistance changes from a high resistance state to a low resistance state, and this process is the setting process (Set process) of the resistance. In process 2, as the voltage decreases, the device remains in a low resistance state. In process 3, when a reverse voltage is applied, the resistance changes from a low resistance state to a high resistance state, and this process is the reset process (Reset process) of the resistance. Process 4 maintains a high resistance state. From 1→2→3→4, a complete resistance change process is embodied, and good uniformity can still be maintained after 100 scans.

[0051] like Figure 4 As shown, the single short-term memory test results of the photoelectric memristor prepared in Example 1 under different light intensities, the current rising process corresponds to the memory process, the current falling process corresponds to the forgetting process, and as the light intensity increases, the time required for forgetting is longer.

[0052] like Figure 5 As shown, the results of multiple short-term memory tests of the photoelectric memristor prepared in Example 1 under different light intensities indicate that frequent learning and stronger light intensity can increase memory strength and gradually transform it into long-term memory.

[0053] like Figure 6 As shown, it is the single long-term memory test result of the photoelectric memristor prepared in this embodiment 1. As the light signal time increases, the current intensity gradually increases and the forgetting time gradually prolongs.

[0054] The above results show that the device has the ability to perceive and remember optical signals, and can realize learning and forgetting processes under optical signals of different light intensities, durations and signal numbers, providing the necessary conditions for the application of artificial vision systems.

[0055] like Figure 7 As shown in the figure, the long-term memory test results of the photoelectric memristor array prepared in Example 1 are shown in the figure. -2 After the light signal was continuously irradiated for 500ms, the array obtained the information of the "arrow". One hour later, the points that were not directly irradiated returned to their initial state, while the state of the points that were directly irradiated was retained, showing a clear "arrow" outline. After applying an erase pulse (-2V, 100ms), the array returned to its initial state. The gray array schematic shows that the device states before and after erasure are different at a smaller current accuracy, indicating that the array can be repeatedly stored and erased. Long-term memory tests have shown that the photoelectric memristor array has both the "recognition-memory-forgetting" ability of the human visual system and the ability to store and erase optical information.

[0056] The above scheme is only a description of the preferred implementation method of the present application, but the protection scope of the present application is not limited to this. Any person familiar with the technology can easily implement it within the scope of the description of the present application without changing the changes or substitutions involved in the basic principles of the claims, which should be covered by the protection scope of the present application, that is, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A photoelectric memristor based on amorphous gallium oxide, characterized in that: The invention comprises a top electrode (1), a functional layer (2), a bottom electrode (3) and a substrate (4) which are arranged in sequence from top to bottom. The top electrode (1) is a transparent electrode, the functional layer (2) is an amorphous Ga2O3 film, and the bottom electrode (3) is an inert electrode.

2. The photoelectric memristor based on amorphous gallium oxide according to claim 1, characterized in that: The transparent electrode used in the top electrode (1) is one of ITO and AZO.

3. The photoelectric memristor based on amorphous gallium oxide according to claim 1, characterized in that: The thickness of the amorphous Ga2O3 film of the functional layer (2) is 30-200nm.

4. The photoelectric memristor based on amorphous gallium oxide according to claim 1, characterized in that: The inert electrode used in the bottom electrode (3) is one of gold, platinum, ruthenium, palladium, rhodium, osmium and iridium.

5. The photoelectric memristor based on amorphous gallium oxide according to claim 1, characterized in that: The substrate (4) is a SiO2 / Si substrate.

6. A method for preparing a photoelectric memristor based on amorphous gallium oxide, characterized in that: The method comprises the following steps: Step 1: Clean the SiO2 / Si substrate with acetone, alcohol, and deionized water in sequence, and blow dry with nitrogen; Step 2: sputtering deposit a bottom electrode (3) on a SiO2 / Si substrate; Step 3: Cover the bottom electrode (3) with a mask, and then prepare an amorphous gallium oxide film; Step 4: Prepare a transparent electrode array on the amorphous gallium oxide film using a mask.

7. The method for preparing a photoelectric memristor based on amorphous gallium oxide according to claim 6, characterized in that: The conditions for preparing the bottom electrode (3) in step 2 are: vacuum degree 1.0-1.6 Pa, time 1-5 min.

8. The method for preparing a photoelectric memristor based on amorphous gallium oxide according to claim 6, characterized in that: The conditions for preparing the amorphous gallium oxide film in step 3 are: background vacuum degree 3.0×10 -4 Pa, argon flow rate is 20-30sccm, sputtering pressure is 0.8-1.2Pa, sputtering power is 60-90W, and sputtering time is 5-30min.

9. The method for preparing a photoelectric memristor based on amorphous gallium oxide according to claim 6, characterized in that: The conditions for preparing the transparent electrode in step 4 are: background vacuum degree 3.0×10 -4 Pa, argon flow rate is 20-30sccm, sputtering pressure is 0.8-1.2Pa, sputtering power is 50-80W, and sputtering time is 5-30min.

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