A high-storage-window memristor based on Mg-doped amorphous Y₂O₃ thin film, its fabrication method and application

Abstract

The application discloses a high-storage-window memristor based on Mg ion doped amorphous Y2O3 film and a preparation method and application thereof, and belongs to the field of nonvolatile memories. The preparation steps of the high-storage-window memristor are as follows: a metal conductive film is deposited on a suitable non-conductive substrate as a lower electrode of the high-storage-window memristor; Mg ions and amorphous Y2O3 film are deposited on the lower electrode in a sputtering mode to form Mg ion doped Mg:Y2O3 film as a storage layer of the high-storage-window memristor; a metal conductive film is deposited on the storage layer as an upper electrode of the high-storage-window memristor, so that the high-storage-window memristor based on the Mg ion doped amorphous Y2O3 film is obtained, and the high-storage-window memristor has the advantages of simple structure, controllable preparation method, economy and environmental protection. By controlling the interstitial substitution of Mg ions to the lattice of the amorphous Y2O3, the formation energy of defects is changed, the storage window is effectively improved, and the high-storage-window memristor has a good market application prospect in the aspect of scaling.

Description

Technical Field

[0001] This invention belongs to the field of non-volatile memory technology, specifically relating to a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film, its preparation method, and its application. Background Technology

[0002] In recent years, with the development of data technologies such as artificial intelligence and machine learning, the demand for high-density storage devices has been increasing. However, the development of traditional memory technology is approaching its theoretical limits, and miniaturization of devices is becoming increasingly difficult. Therefore, limited by the bottlenecks in existing materials and processes, there is an urgent need for a new type of non-volatile memory with high performance, high density, and high stability. Among them, resistive random access memory (RRAM) is considered to be the next generation of high-performance non-volatile memory and one of the most promising candidate devices for artificial intelligence and neuromorphic applications, possessing advantages such as compatibility with complementary metal-oxide-semiconductor (CMOS) technology, simple structure, and high integration density. For resistive storage media, various materials have been reported to exhibit resistive switching behavior, among which yttrium oxide (YO) has attracted attention as a promising resistive switching material in recent years. As is well known, Y2O3 has excellent electrical properties, exhibiting wide bandgap (5.6 eV), low leakage current, high breakdown voltage, and good thermal stability. In particular, amorphous Y2O3 is usually rich in oxygen vacancy defects, which provides great potential for resistive switching memory applications based on oxygen ion migration.

[0003] However, for large-scale integration of information storage, memristors based on Y₂O₃ thin films still require some improvements, such as increasing the memory window. Currently reported yttrium oxide resistive memories exhibit a small current ratio between high and low resistance states, making misreading between resistance states prone to occur. Therefore, obtaining memristors with a large memory window is particularly important. Furthermore, with technological advancements, researchers are increasingly focusing on various device performance characteristics, such as high-precision identification, low power consumption, environmental friendliness, sustainability, and high-density storage, all of which require memristors to have a large memory window. Currently, many methods have been explored to improve the memory window without changing the resistive layer material structure, such as replacing the top electrode material, inserting functional layers, and elemental doping. Doping is undoubtedly a convenient material improvement method. However, not all metal doping significantly improves the memory window; in some cases, it can even lead to a reduction in the memory window. In metal oxide-based resistive memories, resistive switching is generally considered to be caused by the formation / breakage of oxygen vacancy conductance filaments. Therefore, improving the memory window of this device can be achieved by adjusting the oxygen vacancy content in the resistive functional layer.

[0004] However, currently, memristors based on Y2O3 thin films have the problem of a small storage window, which increases the possibility of misreading and restricts their application prospects. There are no reports on the preparation of memristors with a high storage window by doping Y2O3 amorphous thin films with Mg ions. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a high storage window memristor based on Mg ion-doped amorphous Y2O3 thin film, its preparation method and application, so as to solve the technical problem of small storage window of existing Y2O3 thin film-based memristors.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film, comprising the following steps:

[0008] 1) A metal conductive film is deposited on a non-conductive substrate using a sputtering process as the lower electrode;

[0009] 2) A Mg ion and amorphous Y2O3 thin film is deposited on the lower electrode obtained in step 1) by sputtering process to form a Mg ion doped amorphous Y2O3 thin film as a storage layer;

[0010] 3) A metal conductive film is deposited on the storage layer obtained in step 2) using a sputtering process as the top electrode; a high storage window memristor based on Mg ion-doped amorphous Y2O3 film is obtained.

[0011] Preferably, in step 2), Mg ions and amorphous Y2O3 thin films are deposited by co-sputtering; in the formed Mg ion-doped amorphous Y2O3 thin film, the doping concentration of Mg ions is 2% to 10% of that of Y ions.

[0012] Preferably, in step 2), during the deposition of Mg ions and amorphous Y2O3 thin films, the temperature of the non-conductive substrate is 100~350 ℃; and argon and oxygen are introduced simultaneously; the argon flow rate is 5~20 sccm, and the oxygen flow rate is 5~20 sccm.

[0013] Preferably, in step 2), the deposition time of Mg ions and amorphous Y2O3 thin film is 200-400 seconds.

[0014] Preferably, in step 2), the sputtering source for the Mg ions is a high-purity magnesium target; the sputtering source for the amorphous Y2O3 thin film is a high-purity yttrium target.

[0015] Preferably, in step 2), the sputtering power of the magnesium target is 2 to 10 watts; the sputtering power of the yttrium target is 50 to 200 watts.

[0016] Preferably, the non-conductive substrate is SiO2 / Si or highly planarized non-conductive glass; the lower electrode is a conductive thin film of gold, platinum, copper or ITO; and the upper electrode is a conductive thin film of gold, platinum, copper or ITO.

[0017] Preferably, the thickness of the lower electrode is 80–150 nanometers; the thickness of the upper electrode is 50–200 nanometers; and the shape of the upper electrode is controlled by a circular mask with a diameter of 20–200 micrometers.

[0018] The present invention also discloses a high-storage-window memristor based on a Mg ion-doped amorphous Y2O3 thin film prepared by the above preparation method.

[0019] The present invention also discloses the application of the above-mentioned high storage window memristor based on Mg ion-doped amorphous Y2O3 thin film in non-volatile memory.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention discloses a method for fabricating a high-memory-window memristor based on Mg-doped amorphous Y₂O₃ thin films. Y₂O₃ currently possesses excellent electrical properties, especially amorphous Y₂O₃, which is typically rich in oxygen vacancy defects, offering great potential for the application of oxygen ion migration-based memristors. However, current memristors based on Y₂O₃ thin films suffer from a small memory window, which increases the possibility of misreading and limits their application prospects. This invention utilizes alkali metal Mg ions to controllably dope and modify amorphous Y₂O₃ thin films. By controlling the substitution of interstitial sites in the lattice of amorphous Y₂O₃ by Mg ions, the defect formation energy is altered, thereby modifying the electrical properties of the amorphous Y₂O₃ thin film. Using this as a storage layer, a resistive switching device is constructed, resulting in a memristor with a high memory window. Compared to undoped amorphous Y₂O₃ thin film memristors, the memory window is effectively improved, showing broad application prospects in the field of non-volatile memory. A stable and reliable upper electrode is obtained by depositing a conductive metal film on a non-conductive substrate using sputtering, thus ensuring the high reliability of the memristor. A Mg-doped amorphous Y₂O₃ film is then deposited on the lower electrode using sputtering to form a Mg-doped amorphous Y₂O₃ film, which serves as the storage layer. This effectively controls and analyzes the concentration of defects related to storage characteristics within the storage layer, which is crucial for improving the storage window. A conductive metal film is then deposited on the storage layer using sputtering to obtain the upper electrode, further ensuring the realization of a high-storage-window memristor. The resulting high-storage-window memristor is based on a Mg-doped amorphous Y₂O₃ film.

[0022] Furthermore, Mg ions and amorphous Y2O3 thin films are co-sputtered to achieve controllable doping. This method helps to achieve uniform doping of Mg ions. However, if Y2O3 thin film is sputtered first and then Mg ions are sputtered sequentially, the doping uniformity of the prepared film is poor, and the performance of the prepared device deteriorates.

[0023] Furthermore, during the deposition of Mg ions and amorphous Y2O3 thin films, argon and oxygen are introduced. The argon flow rate is 5~20 sccm, and the oxygen flow rate is 5~20 sccm. If the flow rate is too low, the thickness of the prepared film cannot be controlled; if the flow rate is too high, the stability of the prepared device is poor.

[0024] Furthermore, it is crucial to select appropriate substrate growth temperature and reaction time. If the substrate growth temperature is too low, the prepared resistive switching film will have too many defects, affecting device performance; if the substrate temperature is too high, the film will have uneven doping, resulting in poor stability of the resistive switching characteristics. If the growth time is too short, the prepared resistive switching layer will be too thin, making the device prone to breakdown; an excessively thick storage layer will degrade the device's resistive switching performance.

[0025] Furthermore, the sputtering source for Mg ions is a magnesium target; the sputtering source for amorphous Y2O3 thin films is a yttrium target, which helps to improve the flatness and density of the sputtered thin films. Moreover, by adjusting the reaction atmosphere, it is helpful to control the defect density. However, by selecting ceramic targets, the defect control range of the prepared thin films is relatively small, and the resistive switching performance of the prepared devices is poor.

[0026] Furthermore, the sputtering power of yttrium targets is 50~200 watts, and the sputtering power of magnesium targets is 2~10 watts. Below this sputtering power range, the efficiency of the prepared thin film is low; above this power range, the flatness of the prepared thin film is poor, which in turn affects the performance of the device.

[0027] Furthermore, choosing highly planarized non-conductive glass as a substrate can satisfy the fabrication of transparent memristors and provide a basis for the optically modulated characteristics of resistive switching performance; choosing SiO2 / Si as a substrate is compatible with mainstream semiconductor chip CMOS processes and has potential for large-scale production.

[0028] Furthermore, by selecting the upper and lower electrodes of the ITO transparent conductive thin film device and combining them with a planarized glass substrate, a transparent memristor can be realized; by selecting inert metals gold and platinum as the upper and lower electrodes of the device, resistive switching behavior involving only oxygen holes can be achieved, resulting in better controllability of the resistive switching; by selecting active metal copper as the upper and lower electrodes of the device, both active metals and oxygen holes can participate in the resistive switching behavior, providing greater controllability of the resistive switching performance.

[0029] Furthermore, the thickness of the lower electrode is selected to be 80–150 nanometers, and the thickness of the upper electrode is selected to be 50–200 nanometers. If the electrode thickness is less than this range, electrical breakdown will occur during electrical testing; if it is greater than this range, the adhesion between the electrode and the resistive switching layer will decrease, and the stability of the memristor will deteriorate.

[0030] Furthermore, the upper electrode deposition uses a circular mask with a diameter of 20 to 200 micrometers. A smaller diameter is beneficial for fabricating higher density devices, but if the radius is too small, it will affect the stability of the memristor, and if it is too large, it will affect the storage density of the device.

[0031] This invention also discloses a high-storage-window memristor based on Mg-ion-doped amorphous Y2O3 thin film prepared by the above preparation method. It has a simple structure, controllable preparation method, is economical and environmentally friendly, and has good market application prospects in terms of large-scale production.

[0032] This invention also discloses the application of the above-mentioned high storage window memristor based on Mg ion-doped amorphous Y2O3 thin film in non-volatile memory. By controlling the substitution of interstitial sites of amorphous Y2O3 lattice by Mg ions, the formation energy of defects is changed, thereby modifying the electrical properties of amorphous Y2O3 thin film. Compared with undoped amorphous Y2O3 thin film memristors, its storage window is effectively improved, and it has broad application prospects in the field of non-volatile memory. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of a high-storage-window memristor based on a Mg-ion-doped amorphous Y2O3 thin film prepared according to Embodiment 1 of the present invention;

[0034] Figure 2 The image shows the XRD pattern of an amorphous Y2O3 thin film based on Mg ion doping prepared according to Embodiment 1 of the present invention.

[0035] Figure 3 This is a SEM image of an Mg ion-doped amorphous Y2O3 thin film prepared according to Embodiment 1 of the present invention.

[0036] Figure 4 This is a voltage-current curve of a Mg ion-doped amorphous Y2O3 thin film memristor obtained in Embodiment 1 of the present invention;

[0037] Figure 5 This invention relates to a multi-level storage performance of a Mg-doped amorphous Y2O3 thin-film memristor prepared according to Embodiment 1 of the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] The present invention will now be described in further detail with reference to the accompanying drawings:

[0041] Currently, there are no reports on the fabrication of memristors with high storage windows by doping amorphous Y₂O₃ thin films with Mg ions. Therefore, this invention achieves high storage window memristors through controlled doping of amorphous Y₂O₃ thin films with Mg ions.

[0042] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0043] A suitable non-conductive substrate is selected, and a metal conductive film is deposited on the substrate using a sputtering process as the lower electrode of the memristor. Using a sputtering method, the operating power, substrate deposition temperature, reaction gas flow rate, and time are controlled to deposit Mg ion and amorphous Y2O3 films on the lower electrode to form a Mg ion-doped Mg:Y2O3 film, which serves as the storage layer of the high storage window memristor. Furthermore, a metal conductive film is deposited on the memristor storage layer using a sputtering process as the upper electrode, thus preparing a high storage window memristor based on a Mg ion-doped amorphous Y2O3 film.

[0044] Specifically, the non-conductive substrate is SiO2 / Si or highly planarized non-conductive glass;

[0045] Specifically, the lower and upper electrodes are conductive thin films of gold, platinum, copper, or ITO;

[0046] Specifically, the thickness of the lower electrode is 80–150 nanometers, and the thickness of the upper electrode is 50–200 nanometers.

[0047] Specifically, a circular mask with a diameter of 20 to 200 micrometers is used to deposit the upper electrode to control its shape. The mask is placed on the resistive switching layer and then the upper electrode is deposited, which allows for better testing of the device.

[0048] Specifically, a high-purity magnesium metal target is selected as the sputtering source for Mg ions; a high-purity yttrium metal target is selected for the preparation of amorphous Y2O3 thin films.

[0049] Specifically, the sputtering of Mg ions and amorphous Y2O3 thin films is achieved through co-sputtering to achieve controlled doping;

[0050] Specifically, the sputtering power of yttrium targets is 50-200 watts, the sputtering power of magnesium targets is 2-10 watts, and the doping concentration of Mg ions is 2%-10% of that of Y ions;

[0051] Specifically, during the deposition of the storage layer, the substrate needs to be maintained at 100~350℃;

[0052] Specifically, during the deposition of the storage layer, the argon flow rate is 5~20 sccm; the oxygen flow rate is 5~20 sccm.

[0053] Specifically, the storage layer deposition time is 200-400 seconds.

[0054] This invention provides a high-memory window memristor based on Mg-doped amorphous Y₂O₃ thin film. The device structure, from bottom to top, consists of a lower electrode, a Mg-doped amorphous Y₂O₃ thin film, and a top electrode, belonging to the field of non-volatile memory. Compared to undoped amorphous Y₂O₃ thin film memristors, the memristor fabricated using Mg-doped amorphous Y₂O₃ thin film exhibits a higher memory window, achieving a memory window as high as 10. 5 It exhibits excellent resistive switching performance.

[0055] This invention provides a method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y₂O₃ thin film, comprising the following steps:

[0056] S1. Select a suitable non-conductive substrate and use sputtering technology to deposit a metal conductive thin film on the substrate as the lower electrode of the memristor;

[0057] Preferably, SiO2 / Si is selected as the substrate for the high storage window memristor;

[0058] Preferably, the lower electrode is deposited using a sputtering process;

[0059] Preferably, the lower electrode is an inert metal Pt conductive thin film, and the thickness of the lower electrode is 100 nanometers.

[0060] S2. Using a sputtering method, the operating power, substrate deposition temperature, reaction gas flow and time are controlled to deposit Mg ion and amorphous Y2O3 thin films on the lower electrode to form a Mg ion-doped Mg:Y2O3 thin film, which serves as the storage layer of a high storage window memristor.

[0061] Preferably, a magnesium metal target and a yttrium metal target are used as sputtering sources;

[0062] Preferably, the doped Mg:Y2O3 thin film is prepared by co-sputtering;

[0063] Preferably, the sputtering power of the yttrium target and the magnesium target is 100 watts and 5 watts, respectively;

[0064] Preferably, the substrate needs to be maintained at 250°C during the deposition process;

[0065] Preferably, the deposition time is 300 seconds;

[0066] S3. Further, a metal conductive film is deposited on the memristor storage layer as the top electrode using a sputtering process to prepare a high storage window memristor based on a Mg ion-doped amorphous Y2O3 film.

[0067] Preferably, the upper electrode is fabricated using a circular mask with a diameter of 100 micrometers;

[0068] Preferably, the upper electrode is deposited using a sputtering process;

[0069] Preferably, an inert metal Pt conductive film is deposited on the upper electrode, and the thickness of the upper electrode is 100 nanometers.

[0070] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0071] Example 1

[0072] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0073] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0074] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0075] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0076] Please see Figure 1 This is a schematic diagram of a high storage window memristor based on a Mg ion-doped amorphous Y2O3 thin film prepared in Example 1. From bottom to top, it consists of a SiO2 / Si substrate, a Pt lower electrode, a Mg ion-doped amorphous Y2O3 thin film resistive switching storage layer, and a Pt upper electrode.

[0077] Please see Figure 2 The image shows the XRD pattern of an amorphous Y2O3 thin film based on Mg ion doping prepared in Example 1. It can be seen from the image that apart from the peak of the substrate silicon, there are no other obvious diffraction peaks, indicating that the prepared thin film is amorphous.

[0078] Please see Figure 3 The image shown is a SEM image of an amorphous Y2O3 thin film based on Mg ion doping prepared in Example 1. It can be seen that the prepared film has no pinhole-like pores and has high flatness and density.

[0079] Please see Figure 4 The figure shows the voltage-current curve of a Mg-doped amorphous Y2O3 thin film memristor prepared in Example 1. It can be seen from the figure that the resistive switching device exhibits stable bipolar characteristics and has a large storage window.

[0080] Please see Figure 5 The multi-level storage performance of a Mg ion-doped amorphous Y2O3 thin film memristor prepared in Embodiment 1 of this invention is shown to be effective and clear in achieving different resistance states by changing the limiting current, which has good prospects in multi-value storage.

[0081] Example 2

[0082] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0083] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0084] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y₂O₃ thin films. Mg:Y₂O₃ thin films were prepared by first depositing Y₂O₃ and then sputtering the Mg target. The sputtering powers of the yttrium and magnesium targets were 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions. During the deposition process, the substrate was kept at 250°C. The flow rates of both argon and oxygen were 15 sccm. The deposition time was 300 seconds.

[0085] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0086] Example 2 uses a sequential method of first depositing Y2O3 and then depositing Mg ions to prepare the storage layer. The resulting device has a smaller storage window and lower stability.

[0087] Example 3

[0088] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0089] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0090] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 2 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0091] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0092] In Example 3, the sputtering power of the magnesium target was 2 watts. The prepared resistive switching layer had a low Mg ion doping concentration and did not obtain a high storage window.

[0093] Example 4

[0094] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0095] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0096] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 10 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0097] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0098] In Example 4, the sputtering power of the magnesium target was 10 watts. The Mg ion doping concentration of the prepared resistive switching layer was too high. Although the prepared device had a high storage window, its stability was poor.

[0099] Example 5

[0100] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0101] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0102] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 200 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0103] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0104] In Example 5, the sputtering power of the sputtered metal yttrium target was 200 watts. The thickness of the prepared resistive switching layer was too thick, and the resistive switching characteristics of the device were unstable.

[0105] Example 6

[0106] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0107] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0108] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 100 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0109] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0110] In Example 6, the substrate temperature was kept at 100 °C. The surface of the prepared resistive switching layer was not uniform, and the resistive switching characteristics of the device were unstable.

[0111] Example 7

[0112] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0113] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0114] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be maintained at 350 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0115] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0116] In Example 7, the substrate temperature was maintained at 350 °C. The prepared resistive switching layer also had an uneven surface, and the resistive switching characteristics of the device were unstable.

[0117] Example 8

[0118] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0119] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0120] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate was kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 200 seconds.

[0121] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0122] In Example 7, the deposition time was 200 seconds, resulting in a thin resistive switching layer that made the memristor easily damaged.

[0123] Example 9

[0124] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0125] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0126] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 400 seconds.

[0127] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0128] In Example 9, the deposition time was 400 seconds, and the thickness of the prepared resistive switching layer was too thick, resulting in unstable resistive switching characteristics of the memristor.

[0129] Example 10

[0130] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0131] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a Pt metal conductive film with a thickness of 80 nanometers was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0132] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0133] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0134] In Example 10, the thickness of the lower electrode is 80 nanometers. Due to the thinness of the lower electrode, the stability of the memristor cannot be guaranteed, and it exhibits certain fluctuations.

[0135] Example 11

[0136] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0137] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 150-nanometer thick Pt metal conductive film was deposited on the substrate using a sputtering process as the lower electrode of the memristor.

[0138] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0139] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0140] In Example 10, the thickness of the lower electrode is 150 nanometers. The thickness of the lower electrode is relatively large. Although the stability of the memristor is good, its performance is basically the same as that of a memristor with a thickness of 100 nanometers. The excessively thick lower electrode leads to a waste of resources.

[0141] Example 12

[0142] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0143] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer-thick ITO conductive film was deposited on the substrate using a sputtering process as the lower electrode of the memristor.

[0144] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0145] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick ITO conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0146] In Example 12, ITO was used to fabricate the memristor for the upper and lower electrodes. Although the performance of the memristor remained basically unchanged, it was prone to failure under higher voltages, and the reliability of the device could not be guaranteed.

[0147] Example 13

[0148] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0149] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a Cu metal conductive film with a thickness of 100 nanometers was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0150] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0151] 3) Using a circular mask with a diameter of 100 micrometers, a Cu metal conductive film with a thickness of 100 nanometers was deposited on the storage layer as the upper electrode of the memristor using the sputtering process.

[0152] In Example 13, Cu was used to fabricate a memristor for the upper and lower electrodes. Although the performance of the memristor remained basically unchanged, the stability deteriorated as the number of resistive switching cycles increased due to the high activity of Cu.

[0153] Example 14

[0154] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0155] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0156] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 50 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0157] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0158] In Example 14, the sputtering power of the metal yttrium target was 50 watts. At this power, the thickness of the film prepared by sputtering was relatively thin, and the stability of the memristor prepared was poor.

[0159] Example 15

[0160] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0161] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0162] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 2% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0163] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0164] In Example 15, the doping concentration of Mg ions was 2% of that of Y ions. This doping concentration was relatively low, and the storage window of the prepared memristor was not optimized.

[0165] Example 16

[0166] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0167] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0168] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 10% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0169] 3) Using a circular mask with a diameter of 100 micrometers, a 100-nanometer thick Pt metal conductive film is deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0170] In Example 16, the doping concentration of Mg ions was 10% of that of Y ions. At this higher doping concentration, the memory window of this memristor also decreased compared to the device with a doping concentration of 5%.

[0171] Example 17

[0172] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0173] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0174] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 5 sccm; and the deposition time was 300 seconds.

[0175] 3) Using a circular mask with a diameter of 20 micrometers, a 100-nanometer thick Pt metal conductive film was deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0176] In Example 17, both the argon and oxygen flow rates were 5 sccm. At this low flow rate, the thickness of the resistive switching layer was thin, affecting the stability of the device. The mask diameter was 20 micrometers; at this small diameter, the device stability deteriorated.

[0177] Example 18

[0178] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0179] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0180] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 20 sccm; and the deposition time was 300 seconds.

[0181] 3) Using a circular mask with a diameter of 200 micrometers, a 100-nanometer thick Pt metal conductive film was deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0182] In Example 18, the flow rates of both argon and oxygen were 20 sccm. At this high flow rate, the surface roughness of the prepared resistive switching layer was relatively large, which affected the reliability and stability of the memristor. The diameter of the mask was 200 micrometers. At this large diameter, the storage density of the device was reduced.

[0183] Example 19

[0184] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0185] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a gold conductive film with a thickness of 100 nanometers was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0186] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0187] 3) Using a circular mask with a diameter of 100 micrometers, a gold conductive film with a thickness of 50 nanometers was deposited on the storage layer as the upper electrode of the memristor using a sputtering process.

[0188] In Example 19, the thickness of the lower electrode is 100 nanometers and the thickness of the upper electrode is 50 nanometers. Due to the thinness of the upper electrode, the stability of the memristor cannot be guaranteed, and it exhibits certain fluctuations. Similarly, gold is used as the upper and lower electrodes, and the performance of the prepared memristor is basically consistent with that of Pt, but the cost of gold is relatively high.

[0189] Example 20

[0190] A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y2O3 thin film includes the following steps:

[0191] 1) SiO2 / Si was selected as the substrate for the high storage window memristor, and a 100-nanometer thick Pt metal conductive film was deposited on the substrate by sputtering process as the lower electrode of the memristor.

[0192] 2) High-purity magnesium and yttrium targets were selected as raw materials for depositing Mg ions and amorphous Y2O3 thin films; Mg:Y2O3 thin films were prepared by co-sputtering; the sputtering power of the yttrium and magnesium targets was 100 W and 5 W, respectively, and the doping concentration of Mg ions was 5% of that of Y ions; during the deposition process, the substrate needed to be kept at 250 °C; the flow rates of argon and oxygen were both 15 sccm; and the deposition time was 300 seconds.

[0193] 3) Using a circular mask with a diameter of 100 micrometers, a Pt metal conductive film with a thickness of 200 nanometers was deposited on the storage layer as the upper electrode of the memristor using the sputtering process.

[0194] In Example 20, the thickness of the lower electrode is 100 nanometers and the thickness of the upper electrode is 200 nanometers.

[0195] In summary, the method for fabricating a high-storage-window memristor based on Mg-doped amorphous Y₂O₃ thin film proposed in this invention has the following characteristics:

[0196] 1) The present invention proposes a high storage window memristor based on Mg ion-doped amorphous Y2O3 thin film. The structure is simple. By controllably doping the amorphous Y2O3 thin film with Mg ions, the memristor device prepared by the present invention has a high storage window.

[0197] 2) Compared with undoped amorphous Y2O3 thin film memristors, the device prepared in this invention has not only a higher storage window, but also stable properties.

[0198] 3) The present invention proposes a high storage window memristor based on Mg ion-doped amorphous Y2O3 thin film. The preparation method is controllable, economical and environmentally friendly, and has good market application prospects in terms of large-scale production.

[0199] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y₂O₃ thin film, characterized in that, Includes the following steps: 1) A metal conductive film is deposited on a non-conductive substrate using a sputtering process as the lower electrode; 2) A Mg ion and amorphous Y2O3 thin film is deposited on the lower electrode obtained in step 1) by sputtering process to form a Mg ion doped amorphous Y2O3 thin film as a storage layer; the Mg ion and amorphous Y2O3 thin film are deposited by co-sputtering. 3) A metal conductive film is deposited on the storage layer obtained in step 2) using a sputtering process as the top electrode; a high storage window memristor based on Mg ion-doped amorphous Y2O3 film is obtained.

2. The method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y₂O₃ thin film according to claim 1, characterized in that, In step 2), Mg ions and amorphous Y2O3 films are deposited by co-sputtering; in the formed Mg ion-doped amorphous Y2O3 film, the doping concentration of Mg ions is 2% to 10% of that of Y ions.

3. The method for fabricating a high-storage-window memristor based on Mg-ion-doped amorphous Y₂O₃ thin film according to claim 1, characterized in that, In step 2), during the deposition of Mg ions and amorphous Y2O3 thin films, the temperature of the non-conductive substrate is 100~350 ℃; and argon and oxygen are introduced simultaneously; the argon flow rate is 5~20 sccm, and the oxygen flow rate is 5~20 sccm.

4. The method for fabricating a high-storage-window memristor based on Mg-ion-doped amorphous Y₂O₃ thin film according to claim 1, characterized in that, In step 2), the deposition time for Mg ions and amorphous Y2O3 thin films is 200-400 seconds.

5. The method for fabricating a high-storage-window memristor based on Mg-ion-doped amorphous Y₂O₃ thin film according to claim 1, characterized in that, In step 2), the sputtering source for the Mg ions is a high-purity magnesium target; the sputtering source for the amorphous Y2O3 thin film is a high-purity yttrium target.

6. The method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y₂O₃ thin film according to claim 5, characterized in that, In step 2), the sputtering power of the magnesium target is 2 to 10 watts; the sputtering power of the yttrium target is 50 to 200 watts.

7. The method for fabricating a high-storage-window memristor based on Mg-ion-doped amorphous Y₂O₃ thin film according to claim 1, characterized in that, The non-conductive substrate is SiO2 / Si or highly planarized non-conductive glass; the lower electrode is a conductive thin film of gold, platinum, copper or ITO; the upper electrode is a conductive thin film of gold, platinum, copper or ITO.

8. The method for fabricating a high-storage-window memristor based on Mg ion-doped amorphous Y₂O₃ thin film according to claim 1, characterized in that, The thickness of the lower electrode is 80–150 nanometers; the thickness of the upper electrode is 50–200 nanometers; the shape of the upper electrode is controlled by a circular mask with a diameter of 20–200 micrometers.

9. A high-storage-window memristor based on a Mg-ion-doped amorphous Y₂O₃ thin film, prepared by any one of the preparation methods of claims 1 to 8.

10. The application of the high storage window memristor based on Mg ion-doped amorphous Y2O3 thin film as described in claim 9 in non-volatile memory.

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