In-situ vacuum preparation system and preparation method of memristor

Abstract

The application discloses an in-situ vacuum preparation system and a preparation method of a memristor, and belongs to the technical field of electronic device manufacturing. The in-situ vacuum preparation system comprises a glove box, and a vacuum collecting and connecting pipeline is connected to one side of the glove box; the vacuum collecting and connecting pipeline can be used for carrying out the following processes respectively: insulating material thermal evaporation, metal material thermal evaporation, reactive ion etching, ion beam etching, electron beam evaporation and magnetron sputtering; the insulating material evaporation and the electron beam evaporation both adopt an electron beam evaporation device; the metal material thermal evaporation and the magnetron sputtering both adopt a magnetron sputtering device; the reactive ion etching adopts a reactive ion etching device; and the ion beam etching adopts an ion beam etching device. Material deposition and electrode manufacturing in the preparation process of the memristor are carried out in the in-situ vacuum preparation system, material pollution and interface defects are avoided, the performance of the memristor is significantly improved, and the preparation process is simplified.

Description

An in-situ vacuum preparation system and a method for preparing memristors Technical Field

[0001] This invention belongs to the field of electronic device manufacturing technology, specifically relating to an in-situ vacuum preparation system and a method for preparing memristors. Background Technology

[0002] Memristors, or memory resistors, are electronic devices with adjustable resistance and have broad application prospects in memory, computer hardware, and neural networks. Current memristor fabrication methods mainly rely on traditional thin-film deposition techniques, but these methods typically require complex post-processing steps and may introduce material contamination and interface problems during fabrication. Therefore, there is an urgent need for an improved in-situ vacuum fabrication method to simplify the process, improve material purity, and enhance device performance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide an in-situ vacuum preparation system and a method for preparing memristors, thereby solving the problems in the prior art.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] An in-situ vacuum preparation system includes a glove box, one side of which is connected to a vacuum conduit. The vacuum conduit is capable of performing the following processes: thermal evaporation of insulating materials, thermal evaporation of metallic materials, reactive ion etching, ion beam etching, electron beam evaporation, and magnetron sputtering.

[0006] The evaporation of the insulating material and electron beam evaporation are both carried out using electron beam evaporation equipment; the thermal evaporation and magnetron sputtering of the metal material are both carried out using magnetron sputtering equipment; reactive ion etching is carried out using reactive ion etching equipment; and ion beam etching is carried out using ion beam etching equipment.

[0007] Furthermore, the glove box is provided in an argon atmosphere.

[0008] A method for fabricating a memristor, using the aforementioned in-situ vacuum fabrication system, is characterized by comprising the following steps:

[0009] S1. The silicon substrate is ultrasonically cleaned and then placed in the original vacuum preparation system. The bottom electrode, resistive switching layer and top electrode are sequentially prepared on the substrate using magnetron sputtering equipment.

[0010] S2, perform photolithography on the top electrode to control the required parts, and etch the top electrode to remove excess top electrode material;

[0011] S3, perform photolithography and silicon dioxide deposition on the top of the device to form a protective layer, and peel off the excess part;

[0012] S4. Photolithography is performed on the top of the device to control the electrode deposition area, followed by ion washing. Ag is then deposited as the top electrode, and finally the excess is stripped off.

[0013] Furthermore, in S1, the silicon substrate is placed in an ultrasonic instrument and ultrasonicated for 15 minutes each with acetone, anhydrous ethanol, and deionized water in sequence.

[0014] Furthermore, in S2, Al is used as the mask material for photolithography, and reactive ion etching equipment is used for top motor etching.

[0015] Furthermore, in S3, silica deposition is performed using an electron beam evaporation device.

[0016] Furthermore, in S4, ion washing employs ion beam etching equipment, and vapor deposition employs magnetron sputtering equipment.

[0017] A memristor is prepared using the above-described method for preparing a memristor.

[0018] Furthermore, the bottom electrode material is Nb, and the resistive switching layer material is HfO. x The top electrode material is Ag.

[0019] Furthermore, the bottom electrode has a thickness of 50-200 nm, the resistive switching layer has a thickness of 10-100 nm, and the top electrode has a thickness of 50-200 nm.

[0020] The beneficial effects of this invention are:

[0021] 1. This invention uses an in-situ vacuum fabrication system to fabricate memristors, which effectively avoids potential material contamination and interface defects during the memristor production process, thereby significantly improving the overall performance of the memristor.

[0022] 2. The memristor fabrication method proposed in this invention, through ingenious process design, not only greatly simplifies the fabrication process and makes it more efficient, but also significantly reduces material waste.

[0023] 3. Compared with traditional preparation methods, the preparation method of this invention can bring significant improvements to several key performance indicators, including the on / off ratio, stability, and reliability of the memristor. These are important parameters for evaluating the performance of memristors. This invention not only has significant innovations at the technical level, but also shows great potential and value in practical applications, opening up new avenues for the development and application of memristors. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 is a flowchart illustrating the structure and fabrication process of the memristor of the present invention.

[0026] Figure 2 is a schematic diagram of the in-situ vacuum preparation system of the present invention;

[0027] Figure 3 is a graph of the IV test curve of the memristor of the present invention;

[0028] Figure 4 is a current curve under the applied pulse condition of the present invention. Detailed Implementation

[0029] 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 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 are within the scope of protection of the present invention.

[0030] Example 1

[0031] In this embodiment, an in-situ vacuum preparation system is proposed;

[0032] As shown in Figure 2, an in-situ vacuum preparation system includes a glove box with a vacuum conduit connected to one side. The vacuum conduit can perform the following processes: thermal evaporation of insulating materials, thermal evaporation of metallic materials, reactive ion etching (RIE), ion beam etching (IBE), electron beam evaporation (EBE), and magnetron sputtering. The glove box uses an argon atmosphere (H₂O, O₂ PPM < 0.001); the vacuum level of the vacuum conduit is 10⁻⁶. -8 Torr, the vacuum level of each device can reach up to 10. -10 Torr.

[0033] The insulating material evaporation and electron beam evaporation are both carried out using electron beam evaporation equipment; the metal material thermal evaporation and magnetron sputtering are both carried out using magnetron sputtering equipment; reactive ion etching is carried out using reactive ion etching equipment; and ion beam etching is carried out using ion beam etching equipment.

[0034] The memristor completes all the preparation processes in an in-situ vacuum preparation system, thereby avoiding oxidation and contamination during the memristor preparation process and improving the purity and performance of the material.

[0035] In this embodiment, the insulating material is evaporated using an Adnano-tek electron beam evaporation device.

[0036] Thermal evaporation of metallic materials is achieved using Adnano-tek magnetron sputtering equipment.

[0037] Reactive ion etching: Adnano-tek 80RIE;

[0038] Ion beam etching: Adnano-tek IBE;

[0039] Electron beam evaporation is performed using the Adnano-tek electron beam evaporation system.

[0040] The magnetron sputtering method is: Adnano-tek magnetron sputtering equipment;

[0041] The etching and vapor deposition processes are connected via vacuum pipes, with a vacuum level of approximately 1E-6 Torr and a vacuum level of approximately 1E-8 Torr on the equipment walls.

[0042] Example 2

[0043] In this embodiment, a method for fabricating a memristor using the in-situ vacuum fabrication system of Example 1 is proposed, as shown in Figure 1, and specifically includes the following steps:

[0044] S1. Silicon is selected as the substrate and ultrasonically cleaned. Then it is placed in an in-situ vacuum preparation system and the bottom electrode, resistive switching layer and top electrode are sequentially prepared on the substrate using a magnetron sputtering device.

[0045] In S1, the silicon substrate is placed in an ultrasonic instrument and ultrasonicated for 15 minutes each with acetone, anhydrous ethanol, and deionized water in sequence.

[0046] In this embodiment, the vacuum level of the magnetron sputtering equipment is less than 10 when fabricating the bottom electrode, resistive switching layer, and top electrode. -6 Pa, silicon substrate temperature is room temperature 25℃, working pressure is 1Pa, sputtering power is 100W, inert gas protective gas flow rate is 60sccm, time is 60min;

[0047] In other embodiments, the vacuum level of the magnetron sputtering equipment is less than 10 when fabricating the bottom electrode, resistive switching layer, and top electrode. -6 Pa, silicon substrate temperature is room temperature 20-25℃, working pressure is 0.3~1Pa, sputtering power is 30~100W, inert gas protective gas flow rate is 10-60sccm, time is 10-60min.

[0048] In this embodiment, the bottom electrode material is Nb, and the resistive switching layer material is HfO. xThe top electrode material is Ag; in other embodiments, the bottom electrode material may also be a conductive metal, a metal alloy, a conductive metal compound, or other conductive material; the top electrode material may also be a conductive metal, a metal alloy, a conductive metal compound, or other conductive material.

[0049] In this embodiment, the bottom electrode thickness is 50 nm, the resistive switching layer thickness is 40 nm, and the top electrode thickness is 50 nm; in other embodiments, the bottom electrode thickness is 50-200 nm, the resistive switching layer thickness is 10-100 nm, and the top electrode thickness is 50-200 nm.

[0050] In addition, in other embodiments, the bottom electrode and top electrode can also be prepared by ion beam sputtering or chemical vapor deposition.

[0051] S2, perform photolithography on the top electrode to control the required parts, and use reactive ion etching equipment to perform reactive ion etching on the top electrode to remove excess top electrode material (Ag);

[0052] In the photolithography process, Al is used as the mask material to select the desired pattern. A JD8S-A48P ultraviolet lithography machine is used with the following parameters: exposure time of 10 seconds and development time of 20 seconds. In this embodiment, the parameters for reactive ion etching are: CF4 gas as the reactive gas, power of 100W, and reaction time of 5 minutes.

[0053] S3, perform photolithography and silicon dioxide deposition on the top of the device to form a protective layer, and peel off the excess part;

[0054] The process employed a JD8S-A48P ultraviolet lithography machine with an exposure time of 10 seconds and a development time of 20 seconds. Silica deposition was performed using an Adnano-tek electron beam evaporation system with the following parameters: operating voltage of 8kV, electron beam current of 15mA, and deposition rate of 0.5nm / s. Excess material was removed using an ultrasonic stripper with the following parameters: power of 80W and ultrasonic treatment time of 30 seconds / second.

[0055] S4. Photolithography is performed on the top of the device to control the electrode deposition area, followed by ion washing. Ag is then deposited as the top electrode, and finally the excess is stripped off.

[0056] The photolithography process employed a JD8S-A48P ultraviolet lithography machine with an exposure time of 10 seconds and a development time of 20 seconds. Ion washing utilized an Adnano-tek IBE system with an argon ionization voltage of 500V, etching power of 75W, and an etching rate of 1nm / s. Evaporation was performed using an Adnano-tek magnetron sputtering system with a working gas pressure of 2mTorr, DC power of 200W, target-substrate distance of 10mm, and an evaporation rate of 2nm / s. Lifting was completed using an ultrasonic machine with a power of 80W and an ultrasonic treatment time of 30 seconds.

[0057] Example 3

[0058] In this embodiment, the memristor prepared in Example 2 was experimentally tested;

[0059] Figure 3 shows the IV test curve of the memristor. The set voltage (Vset) and reset voltage (Vreset) of the memristor are concentrated in a small range. The average value of Vset / Vreset under the corresponding conditions is -0.87V / 0.80V, which can effectively reduce the overall power consumption. The low voltage operation reduces the heat generation effect, improves the thermal stability of the device, and prevents performance degradation caused by overheating. The lower voltage can also reduce the stress and fatigue of the device, thereby extending the service life of the memristor.

[0060] As shown in Figure 4, after applying a pulse with an amplitude of -2V to the top electrode of the memristor, the resistance of the memristor was successfully controlled by increasing the relative time of the peak signal. As the pulse time increased, the resistance of the memristor decreased, and the current increased. It can be seen that the device prepared by this experimental method can successfully achieve short-term plasticity (STP). This characteristic is similar to the behavior of biological neurons, which helps to realize the function of simulating biological neural networks and shows its potential application in programmable circuits and neural network simulation, especially in information storage and processing.

[0061] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for fabricating a memristor, characterized in that, Includes the following steps: S1. The silicon substrate is ultrasonically cleaned and then placed in an in-situ vacuum fabrication system. A bottom electrode, a resistive switching layer, and a top electrode are sequentially fabricated on the substrate using magnetron sputtering. S2. The top electrode is photolithographically etched to control the required area, and then etched to remove excess material. S3. The top of the device is photolithographically etched and silicon dioxide deposited, and excess material is removed. S4. The top of the device is photolithographically etched to control the electrode deposition area, ion-washed, and then Ag is deposited as the top electrode. Finally, excess material is removed. The top electrode is in direct contact with the resistive switching layer. The top electrode material is Ag, and the resistive switching layer material is... 。 2. The method for fabricating a memristor according to claim 1, characterized in that, In S1, the silicon substrate is placed in an ultrasonic instrument and ultrasonicated for 15 minutes each with acetone, anhydrous ethanol, and deionized water in sequence.

3. The method for fabricating a memristor according to claim 1, characterized in that, In S2, Al is used as the mask material for photolithography, and reactive ion etching equipment is used for etching the top electrode.

4. The method for fabricating a memristor according to claim 1, characterized in that, In S3, silica deposition is performed using an electron beam evaporation device.

5. The method for fabricating a memristor according to claim 1, characterized in that, In S4, ion washing is performed using ion beam etching equipment, and deposition is performed using magnetron sputtering equipment.

6. A memristor, characterized in that, It is prepared using the method for preparing a memristor according to any one of claims 1-5.

7. A memristor according to claim 6, characterized in that, The bottom electrode material is Nb, and the resistive switching layer material is... The top electrode material is Ag.

8. A memristor according to claim 6 or 7, characterized in that, The bottom electrode has a thickness of 50-200 nm, the resistive switching layer has a thickness of 10-100 nm, and the top electrode has a thickness of 50-200 nm.

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