In-situ vacuum preparation system and memristor preparation method

Abstract

The invention discloses an in-situ vacuum preparation system and a memristor preparation method, and belongs to the technical field of electronic device manufacturing. The in-situ vacuum preparation system comprises a glove box, one side of the glove box is connected with a vacuum collecting and connecting pipeline, and insulating material thermal evaporation, metal material thermal evaporation, reactive ion etching, ion beam etching, electron beam evaporation and magnetron sputtering can be conducted in the vacuum collecting and connecting pipeline; the insulating material evaporation and the electron beam evaporation both adopt electron beam evaporation equipment; magnetron sputtering equipment is adopted in the thermal evaporation and magnetron sputtering of the metal material; the reactive ion etching adopts reactive ion etching equipment; according to ion beam etching, material deposition and electrode manufacturing in the memristor preparation process of ion beam etching equipment are both carried out in an in-situ vacuum preparation system, material pollution and interface defects are avoided, the performance of the memristor is remarkably improved, and the preparation technology is simplified.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic device manufacturing, and in particular relates to an in-situ vacuum preparation system and a preparation method of a memristor. Background Art

[0002] Memristor, also known as memory resistor (Memristor), is an electronic device with adjustable resistance. It has broad application prospects in the fields of memory, computer hardware and neural network. The current memristor preparation methods mainly rely on traditional thin film deposition technology, but these methods usually require complex post-processing steps, and there may be material contamination and interface problems during the preparation process. Therefore, an improved in-situ vacuum preparation method is urgently needed to simplify the process flow, improve material purity and device performance. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide an in-situ vacuum preparation system and a method for preparing a memristor, which solve the problems in the prior art.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] An in-situ vacuum preparation system comprises a glove box, one side of which is connected to a vacuum manifold, in which the following operations can be performed: thermal evaporation of insulating materials, thermal evaporation of metal materials, reactive ion etching, ion beam etching, electron beam evaporation and magnetron sputtering;

[0006] The insulating material evaporation and electron beam evaporation both adopt: electron beam evaporation equipment; the metal material thermal evaporation and magnetron sputtering both adopt: magnetron sputtering equipment; reactive ion etching adopts: reactive ion etching equipment; ion beam etching adopts: ion beam etching equipment.

[0007] Furthermore, the glove box adopts an argon environment.

[0008] A method for preparing a memristor, using the above-mentioned in-situ vacuum preparation system, is characterized by comprising the following steps:

[0009] S1, ultrasonically clean the silicon substrate, then put it into the original vacuum preparation system, and use magnetron sputtering equipment to sequentially prepare the bottom electrode, the resistive switching layer and the top electrode on the substrate;

[0010] S2, photolithography the top electrode to control the required part, and etching the top electrode to remove the excess top electrode material;

[0011] S3, photolithography and silicon dioxide deposition are performed on the top of the device to serve as a protective layer, and the excess part is peeled off;

[0012] S4, photolithography is performed on the top of the device to control the electrode evaporation area, and ion washing is performed, and then Ag is evaporated as the top electrode, and finally the excess part is stripped off.

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

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

[0015] Furthermore, in S3, the silicon dioxide is deposited using an electron beam evaporation device.

[0016] Furthermore, in S4, ion washing uses ion beam etching equipment, and evaporation uses magnetron sputtering equipment.

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

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

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

[0020] Beneficial effects of the present invention:

[0021] 1. The present invention prepares memristors by designing an in-situ vacuum preparation system. During the production process of the memristors, possible material contamination and interface defects can be effectively avoided, thereby significantly improving the overall performance of the memristors.

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

[0023] 3. Compared with the traditional preparation method, the technical solution adopted by the preparation method of the present invention can bring significant improvements in multiple key performance indicators, including the switching ratio, stability and reliability of the memristor, which are important parameters for evaluating the performance of the memristor; the present invention not only has significant innovations at the technical level, but also shows great potential and value in practical applications, opening up a new path for the development and application of memristors. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 is the structure of the memristor of the present invention and the flow chart of its preparation;

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

[0027] Figure 3 is an IV test curve diagram of the memristor of the present invention;

[0028] Figure 4 It is a current curve diagram under pulse application conditions of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work 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] like Figure 2 As shown, an in-situ vacuum preparation system includes a glove box, one side of the glove box is connected to a vacuum manifold, and the vacuum manifold can be used for: thermal evaporation of insulating materials, thermal evaporation of metal materials, reactive ion etching (RIE), ion beam etching (IBE), electron beam evaporation (EBE) and magnetron sputtering. The glove box adopts an argon environment (H2O, O2PPM<0.001); the vacuum degree of the vacuum manifold is 10 -8 Torr, the vacuum degree of each device can reach up to 10 -10 Torr.

[0033] Among them, the insulating material evaporation and electron beam evaporation both adopt: electron beam evaporation equipment; the metal material thermal evaporation and magnetron sputtering both adopt: magnetron sputtering equipment; reactive ion etching adopts: reactive ion etching equipment; ion beam etching adopts: 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: Adnano-tek electron beam evaporation equipment;

[0036] Thermal evaporation of metal materials: Adnano-tek magnetron sputtering equipment;

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

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

[0039] Electron beam evaporation was performed using: Adnano-tek electron beam evaporation equipment;

[0040] Magnetron sputtering: Adnano-tek magnetron sputtering equipment;

[0041] The above etching and evaporation are connected through vacuum pipes. The vacuum degree of the pipes is about 1E-6Torr, and the vacuum degree of the equipment wall is about 1E-8Torr.

[0042] Example 2

[0043] In this embodiment, a method for preparing a memristor using the in-situ vacuum preparation system of embodiment 1 is proposed, such as Figure 1 As shown, the specific steps include:

[0044] S1, select silicon as the substrate, perform ultrasonic cleaning, and then put it into an in-situ vacuum preparation system, and use a magnetron sputtering device to sequentially prepare a bottom electrode, a resistive switching layer, and a top electrode on the substrate;

[0045] In S1, the silicon substrate is placed in an ultrasonicator and ultrasonicated for 15 min each using acetone, anhydrous ethanol, and deionized water in sequence.

[0046] In this embodiment, when preparing the bottom electrode, the resistive switching layer and the top electrode, the vacuum degree of the magnetron sputtering device is less than 10 -6 Pa, the silicon substrate temperature is room temperature 25°C, the working pressure is 1Pa, the sputtering power is 100W, the inert gas protection gas flow is 60sccm, and the time is 60min;

[0047] In other embodiments, when preparing the bottom electrode, the resistive switching layer and the top electrode, the vacuum degree of the magnetron sputtering device is less than 10 -6Pa, the silicon substrate temperature is room temperature 20-25°C, the working pressure is 0.3-1Pa, the sputtering power is 30-100W, the inert gas protection gas flow is 10-60sccm, and the time is 10-60min.

[0048] In this embodiment, the bottom electrode material is Nb, and the resistive layer material is HfO x , the 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 one of other conductive materials; the top electrode material may also be a conductive metal, a metal alloy, a conductive metal compound or one of other conductive materials.

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

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

[0051] S2, performing photolithography on the top electrode to control the required portion, and performing reactive ion etching on the top electrode using a reactive ion etching device to remove excess top electrode material (Ag);

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

[0053] S3, photolithography and silicon dioxide deposition are performed on the top of the device to serve as a protective layer, and the excess part is peeled off;

[0054] Among them, the JD8S-A48P ultraviolet lithography equipment is used, and the equipment parameters are exposure time of 10 seconds and development time of 20 seconds. The silicon dioxide deposition adopts Adnano-tek electron beam evaporation equipment, and the equipment parameters are: working voltage of 8kV, electron beam current of 15mA, and evaporation rate of 0.5nm / s. The ultrasonic machine equipment is used to strip off the excess part, and the equipment parameters are: power 80W, ultrasonic 30 seconds /

[0055] S4, photolithography is performed on the top of the device to control the electrode evaporation area, and ion washing is performed, and then Ag is evaporated as the top electrode, and finally the excess part is stripped;

[0056] Among them, the photolithography uses JD8S-A48P ultraviolet lithography equipment, and the equipment parameters are exposure time of 10 seconds and development time of 20 seconds; ion washing uses Adnano-tek IBE equipment, and the equipment parameters are argon ionization voltage of 500V, etching power of 75W, and etching rate of 1nm / s. Evaporation uses Adnano-tek magnetron sputtering equipment, and the equipment parameters are working gas pressure of 2mTorr, DC power of 200W, target substrate distance of 10mm, and evaporation rate of 2nm / s. Stripping uses ultrasonic equipment, power of 80W, and ultrasonic for 30 seconds.

[0057] Example 3

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

[0059] like Figure 3 As shown in the figure, it is the IV test curve of the memristor. The set voltage (Vset) and reset voltage (Vreset) of the memristor are concentrated in a smaller 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 heating effect, improves the thermal stability of the device, and prevents the 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] like Figure 4 As shown, after a pulse with an amplitude of -2V is applied to the top electrode of the memristor, the resistance of the memristor is successfully controlled by increasing the relative time of the peak signal. As the pulse time increases, the resistance of the memristor decreases, showing an increase in current. It can be seen that the device prepared by this experimental method can successfully achieve short-term plasticity (STP), which is similar to the behavior of biological neurons and helps to simulate the function of biological neural networks, showing its potential application in programmable circuits and neural network simulation, especially in information storage and processing capabilities.

[0061] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0062] The above shows and describes 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, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. An in-situ vacuum preparation system, characterized in that: It includes a glove box, one side of which is connected to a vacuum manifold, in which the following processes can be performed: thermal evaporation of insulating materials, thermal evaporation of metal materials, reactive ion etching, ion beam etching, electron beam evaporation and magnetron sputtering; The insulating material evaporation and electron beam evaporation both adopt: electron beam evaporation equipment; the metal material thermal evaporation and magnetron sputtering both adopt: magnetron sputtering equipment; reactive ion etching adopts: reactive ion etching equipment; ion beam etching adopts: ion beam etching equipment.

2. An in-situ vacuum preparation system according to claim 1, characterized in that: The glove box adopts an argon environment.

3. A method for preparing a memristor, using the in-situ vacuum preparation system according to claim 1 or 2, characterized in that: The following steps are involved: S1, ultrasonically clean the silicon substrate, then put it into the original vacuum preparation system, and use magnetron sputtering equipment to sequentially prepare the bottom electrode, the resistive switching layer and the top electrode on the substrate; S2, photolithography the top electrode to control the required part, and etching the top electrode to remove the excess top electrode material; S3, photolithography and silicon dioxide deposition are performed on the top of the device to serve as a protective layer, and the excess part is peeled off; S4, photolithography is performed on the top of the device to control the electrode evaporation area, and ion washing is performed, and then Ag is evaporated as the top electrode, and finally the excess part is stripped off.

4. The method for preparing a memristor according to claim 3, characterized in that: In S1, the silicon substrate is placed in an ultrasonicator and ultrasonicated for 15 min each using acetone, anhydrous ethanol, and deionized water in sequence.

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

6. The method for preparing a memristor according to claim 3, characterized in that: In S3, silicon dioxide is deposited using an electron beam evaporation device.

7. The method for preparing a memristor according to claim 3, characterized in that: In S4, ion washing uses ion beam etching equipment, and evaporation uses magnetron sputtering equipment.

8. A memristor, characterized in that: The memristor is prepared using the method for preparing a memristor as described in any one of claims 3 to 7.

9. A memristor according to claim 8, characterized in that: The bottom electrode material is Nb, and the resistive layer material is HfO x , the top electrode material is Ag.

10. A memristor according to claim 8 or 9, characterized in that: The thickness of the bottom electrode is 50-200nm, the thickness of the resistive layer is 10-100nm, and the thickness of the top electrode is 50-200nm.

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