Gallium oxide resistive random access memory with MXene coated metal particles

Abstract

The invention provides a gallium oxide resistive random access memory with MXene coated metal particles, and belongs to the technical field of semiconductors. The preparation method of the gallium oxide resistive random access memory comprises the following steps: selecting and cleaning a substrate to obtain a cleaned substrate; putting the cleaned substrate on a mask plate, putting the mask plate on electron beam evaporation equipment, and preparing a bottom electrode; performing first magnetron sputtering, and growing a first gallium oxide thin film on the bottom electrode to form a first resistive function layer; preparing an MXene coating layer on the first resistive random function layer through spin coating; preparing a metal particle layer on the MXene coating layer; performing second magnetron sputtering, and growing a second gallium oxide thin film on the metal particle layer to form a second resistive function layer; and evaporating a top electrode on the second gallium oxide thin film to obtain the MXene coated metal particle gallium oxide resistive random access memory.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a gallium oxide resistive random access memory with MXene-coated metal particles. Background Art

[0002] In recent years, the explosive growth of data has driven the demand for high-capacity, high-performance memory. However, due to the physical limitations of devices, traditional flash memory can no longer achieve increased storage density by reducing its size, and its low write speed cannot meet the needs of real-time data processing (such as AI).

[0003] The conductive filament theory is widely recognized as the operating mechanism of resistive random access memory. Among them, the electrochemical mechanism explains the operation of devices with active metals as the top electrodes of resistive random access memory. In this mechanism, the positive set voltage causes the top electrode metal to undergo an oxidation reaction, lose electrons and become ions that move freely in the solid electrolytic material. Under the action of the electric field, it moves toward the cathode, and obtains electrons at the cathode to undergo a reduction reaction and deposit, forming a conductive filament composed of the top electrode metal. On the other hand, the valence change mechanism explains that in addition to the electrochemical reaction of the top electrode metal, the oxygen vacancies inside the resistive random access material also participate in the formation of the conductive filament.

[0004] Previous resistive memory devices mostly replaced the metal constituting the top electrode based on the conductive filament theory, or introduced heterojunctions to regulate the distribution of oxygen vacancies inside the resistive material, thereby optimizing the performance of the device. However, the problem of excessive injection of top electrode metal still exists. In addition, the improvement of device performance (such as the reduction of the set voltage) depends on a large number of experimental trial and error, and is highly random.

[0005] Therefore, it is of great practical significance to provide a new type of memory that has high storage density, high read and write speed, and high reliability to meet the data needs of the information age. Summary of the invention

[0006] The purpose of the present invention is to provide a gallium oxide resistive random access memory with MXene-coated metal particles, aiming to solve the technical problems in the prior art that traditional memories cannot further improve storage density and have strong randomness in device performance and high and unstable error frequency.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a MXene-coated metal particle gallium oxide resistive memory, comprising: a substrate, a bottom electrode, a first resistive functional layer, a MXene coating layer, a metal particle layer, a second

[0009] The resistive switching functional layer and the top electrode;

[0010] Wherein, the first resistive switching functional layer and the second resistive switching functional layer are made of gallium oxide;

[0011] The thickness of the first resistive switching functional layer and the second resistive switching functional layer is 20-30 nm;

[0012] The MXene coating layer is a MXene film prepared by spin coating.

[0013] Preferably, the substrate is made of one of SiO2, sapphire or Si.

[0014] Preferably, the bottom electrode is made of any one of Pt, heavily doped Si or TiN, and the thickness of the bottom electrode is 100-150 nm.

[0015] Preferably, the metal particles used in the metal particle layer are any metal that can form nanoparticles, and the particle size of the metal particles is 2 to 10 nm.

[0016] Preferably, the top electrode is made of active metal material.

[0017] The present invention also provides a method for preparing the MXene-coated metal particle gallium oxide resistive random access memory described in the above technical solution, comprising the following steps:

[0018] Select a substrate and clean it to obtain a cleaned substrate;

[0019] Placing the cleaned substrate on a mask and placing it on an electron beam evaporation device to prepare a bottom electrode;

[0020] Performing a first magnetron sputtering to grow a first gallium oxide film on the bottom electrode to form a first resistive switching functional layer;

[0021] Preparing a MXene coating layer on the first resistive switching functional layer by spin coating;

[0022] preparing a metal particle layer on the MXene coating layer;

[0023] Performing a second magnetron sputtering to grow a second gallium oxide film on the metal particle layer to form a second resistive switching functional layer;

[0024] A top electrode is evaporated on the second gallium oxide film to obtain the gallium oxide resistive random access memory having the MXene-coated metal particles.

[0025] Preferably, the specific conditions of the first magnetron sputtering and the second magnetron sputtering are: sputtering power of 110-130 W, sputtering temperature of 20 ° C, sputtering pressure of 0.6 Pa, argon flow rate of 45 sccm, oxygen flow rate of 5 sccm, sputtering time of 7-12 min, vacuum degree of 5×10-4 ~9×10 -4 Pa, the substrate tray rotates at 10-15 r / min.

[0026] Preferably, the conditions for preparing the MXene coating layer by spin coating are as follows: the concentration of the MXene solution is 2 to 0.5 mg / mL, the spin coating speed is 2000 to 4000 r / min, the spin coating time is 30 s, the heating temperature after spin coating is 70 to 120° C., and the heating time is 8 to 15 min.

[0027] Preferably, the conditions for evaporating the top electrode are as follows: the evaporation current is 100-120A, the evaporation rate is 0.3-0.7nm / s, the vacuum degree is 5×10 -4 ~9×10 -4 Pa, the tray speed is 10~5r / min.

[0028] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0029] (1) The present invention uses wide bandgap semiconductor gallium oxide as the resistive switching functional layer. Based on the excellent resistive switching performance, good thermal stability, compatibility with CMOS technology, and strong light response to deep ultraviolet light, the resistive switching memory of the present invention can realize photoelectric co-modulation;

[0030] (2) The metal particle layer of the present invention uses any metal that can form nanoparticles, preferably Ag, Cu or Au. Since Cu / Ag can migrate through electrochemical reactions in the gallium oxide resistive memory device, the voltage requirement for the formation of conductive filaments is reduced. At the same time, metal particles with a relatively small particle size can produce a local electric field enhancement effect inside the resistive material, so that the electric field is enhanced near the metal particles, further improving the controllability of the formation of conductive filaments. When no metal particles are added, the set voltage of the device floats in the range of 0.4V-1.5V. After adding the metal particle buried layer, the set voltage of the device can be reduced to 0.2V-0.4V, and is relatively stable, with higher stability.

[0031] (3) The present invention uses MXene as a coating layer for metal particles. MXene, as a two-dimensional material, has good conductivity, and its two-dimensional sheet structure can effectively block the participation of active metal particles. When the MXene coating layer is not added, the conductive filaments will be formed directly along the position of the metal particles from the top electrode, and the metal particles will also directly participate in the subsequent formation of the conductive filaments. However, when the MXene coating layer is added, the conductive filaments can only pass through the gaps in the sheet structure, thereby reducing the participation of active metals and effectively increasing the life of the device;

[0032] (4) The present invention uses active metals such as Ag as the top electrode. This metal can effectively reduce the set voltage of the device and increase the storage window in the gallium oxide resistive memory device, so that it has a higher storage density. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the structure of the gallium oxide resistive random access memory with MXene-coated metal particles of the present invention;

[0034] Figure 2 The present invention is a flow chart for preparing the gallium oxide resistive random access memory with MXene-coated metal particles;

[0035] Figure 3 This is a semi-logarithmic current-voltage curve of the gallium oxide resistive random access memory with MXene-coated metal particles described in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] The present invention provides a MXene-coated metal particle gallium oxide resistive memory, comprising: a substrate 1, a bottom electrode 2, a first resistive functional layer 3, a MXene coating layer 4, a metal particle layer 5, a second resistive functional layer 6 and a top electrode 7;

[0037] Wherein, the first resistive switching functional layer 3 and the second resistive switching functional layer 6 are made of gallium oxide;

[0038] The thickness of the first resistive switching functional layer 3 and the second resistive switching functional layer 6 is 20-30 nm;

[0039] The MXene coating layer 4 is a MXene film prepared by spin coating.

[0040] In the present invention, the substrate 1 is made of one of SiO2, sapphire or Si.

[0041] In the present invention, the bottom electrode 2 is made of any one of Pt, heavily doped Si or TiN, and the thickness of the bottom electrode 2 is 100-150 nm.

[0042] In the present invention, the metal particles used in the metal particle layer 5 can be any metal that can form nanoparticles, preferably Ag, Cu or Au; the particle size of the metal particles is preferably 2 to 10 nm.

[0043] The present invention adopts metal materials such as Ag, Cu or Au as the metal particle layer. Since Cu / Ag can migrate through electrochemical reaction in the gallium oxide resistive memory device, the voltage requirement for the formation of conductive filaments is reduced. At the same time, metal particles with relatively low particle size can produce a local electric field enhancement effect inside the resistive material, so that the electric field is enhanced near the metal particles, further improving the controllability of the formation of conductive filaments. When no metal particles are added, the set voltage of the device floats in the range of 0.4V-1.5V. After adding the metal particle buried layer, the set voltage of the device can be reduced to 0.2V-0.4V, and is relatively stable, with higher stability.

[0044] In the present invention, the top electrode 7 is made of active metal material, preferably Ag, Cu, Al or a material having similar properties to Ag, Cu, Al.

[0045] The present invention uses active metals such as Ag as the top electrode. The metal can effectively reduce the set voltage of the device and increase the storage window in the gallium oxide resistive memory device, so that it has a higher storage density.

[0046] The present invention also provides a method for preparing the MXene-coated metal particle gallium oxide resistive random access memory described in the above technical solution, comprising the following steps:

[0047] Select a substrate and clean it to obtain a cleaned substrate;

[0048] Placing the cleaned substrate on a mask and placing it on an electron beam evaporation device to prepare a bottom electrode;

[0049] Performing a first magnetron sputtering to grow a first gallium oxide film on the bottom electrode to form a first resistive switching functional layer;

[0050] Preparing a MXene coating layer on the first resistive switching functional layer by spin coating;

[0051] preparing a metal particle layer on the MXene coating layer;

[0052] Performing a second magnetron sputtering to grow a second gallium oxide film on the metal particle layer to form a second resistive switching functional layer;

[0053] A top electrode is evaporated on the second gallium oxide film to obtain the gallium oxide resistive random access memory having the MXene-coated metal particles.

[0054] Select a substrate and clean it to obtain a cleaned substrate;

[0055] The present invention does not impose any particular limitation on the cleaning means, and any technical means well known to those skilled in the art may be used.

[0056] Placing the cleaned substrate on a mask and placing it on an electron beam evaporation device to prepare a bottom electrode;

[0057] Performing a first magnetron sputtering to grow a first gallium oxide film on the bottom electrode to form a first resistive switching functional layer;

[0058] In the present invention, the specific conditions of the first magnetron sputtering and the second magnetron sputtering are preferably: sputtering power of 110-130 W, sputtering temperature of 20° C., sputtering pressure of 0.6 Pa, argon flow rate of 45 sccm, oxygen flow rate of 5 sccm, sputtering time of 7-12 min, vacuum degree of 5×10 -4 ~9×10 -4 Pa, the substrate tray rotates at 10-15 r / min.

[0059] The present invention uses wide bandgap semiconductor gallium oxide as the resistive switching functional layer. Based on the fact that this material has excellent resistive switching performance, good thermal stability, compatibility with CMOS technology, and strong light response to deep ultraviolet light, the resistive switching memory of the present invention can realize photoelectric co-modulation.

[0060] Preparing a MXene coating layer on the first resistive switching functional layer by spin coating;

[0061] In the present invention, the conditions for preparing the MXene coating layer by spin coating are preferably as follows: the concentration of the MXene solution is 2 to 0.5 mg / mL, the spin coating speed is 2000 to 4000 r / min, the spin coating time is 30 s, the heating temperature after spin coating is 70 to 120° C., and the heating time is 8 to 15 min.

[0062] preparing a metal particle layer on the MXene coating layer;

[0063] When the metal particles are Ag / Au, the process conditions are preferably as follows: the concentration of the Ag / Au suspension is within 0.25-0.01 mg / mL, the spin coating speed is 2000-4000 rpm, the spin coating time is 30 s, the heating temperature after spin coating is 7-120°C, and the heating time is 8-15 min; when the metal particles are Cu, the process conditions are preferably as follows: the sputtering power is 110-130 W, the sputtering temperature is 20°C, the sputtering pressure is 0.6 Pa, the argon flow rate is 50 sccm, the oxygen flow rate is 0 sccm, the sputtering time is within 5-10 s, and the vacuum degree is 5×10 -4 ~9×10 -4 Pa, the substrate tray rotates at 10-15 r / min.

[0064] In the present invention, the conditions for evaporating the top electrode are preferably: the evaporation current is 100-120A, the evaporation rate is 0.3-0.7nm / s, the vacuum degree is 5×10 -4 ~9×10 -4 Pa, the tray speed is 10~5r / min.

[0065] In the present invention, unless otherwise specified, the required raw materials for preparation are all commercially available products well known to those skilled in the art.

[0066] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0067] Example 1

[0068] (1) A 1 cm × 1 cm Si / SiO2 / Ti / Pt sheet was selected as the substrate, which includes a substrate and a bottom electrode. The substrate was ultrasonically cleaned in acetone, alcohol, and deionized water for 15 min each to remove surface impurities. After cleaning, it was blown dry with a nitrogen gun for later use;

[0069] (2) Preparation of the first resistive switching functional layer on the bottom electrode

[0070] The cleaned substrate was fixed on the mask and placed in the magnetron sputtering instrument. The sputtering power was set to 120 W, the sputtering temperature was 20 °C, the sputtering pressure was 0.6 Pa, the argon flow rate was 45 sccm, the oxygen flow rate was 5 sccm, the sputtering time was 7 min, the vertical distance between the substrate tray and the target source was 75 mm, and the vacuum degree was 8x10 -4 The process conditions are as follows: the pressure is 1.2 Pa and the substrate tray rotation speed is 10 r / min, wherein the pressure is first increased to 1.2 Pa with the substrate baffle closed, and then adjusted to 0.6 Pa after observing the glow discharge in the sputtering chamber. After pre-sputtering for 5 minutes, the substrate baffle is opened and sputtering is officially started. A gallium oxide film with a size and shape consistent with the bottom electrode and a thickness of 20 nm is sputtered on the substrate to form a photoelectric memristor functional layer;

[0071] (3) Preparation of MXene coating layer on the first resistive functional layer

[0072] Place the sample with the gallium oxide film sputtered in step 2 into a UV irradiator and irradiate it with UV for 10 minutes to change the hydrophilicity of the film surface. Then, take out the MXene suspension with a concentration of 0.5 mg / ml that has been stirred in advance and spin-coat it on the gallium oxide film after UV irradiation. The spin-coating speed is 3000 rpm and the spin-coating time is 30 seconds. After spin-coating, place the sample on a heating table and heat it at 120°C for 10 minutes to remove moisture from the surface.

[0073] (4) Preparation of Ag metal particle layer on MXene coating layer

[0074] First, put the Ag nanoparticle suspension with a concentration of 0.25 mg / ml into an ultrasonic machine for 3 hours to break up the Ag particle clusters in the suspension and make the Ag particles evenly distributed in the suspension. Then put the sample prepared in step 3 into the UV irradiator again for 10 minutes. Finally, spin-coat the Ag nanoparticle suspension after ultrasound onto the sample at a spin-coating speed of 3000 rpm for 30 seconds. Finally, put the spin-coated sample on a heating table and heat it at 70°C for 10 minutes.

[0075] (5) Preparation of the second resistive switching functional layer on the Ag metal particle layer

[0076] Same as step 2, the sample after spin coating with Ag nanoparticles was fixed on the mask, placed in a magnetron sputtering instrument, and a 20 nm gallium oxide film was sputtered with the same parameters;

[0077] (6) Preparing a top electrode on the second resistive functional layer

[0078] The grown gallium oxide film was placed in a vacuum evaporation device, and the process parameters of the evaporation current was set to 120A, the evaporation rate was set to 0.7nm / s, the vacuum degree was set to 5×10-4Pa, and the tray rotation was set to 10r / min. An Ag electrode with a size of 50μm×50μm and a thickness of 100nm was evaporated on the gallium oxide film to complete the device manufacturing and obtain the MXene-coated metal particle gallium oxide resistive memory, whose structure is as follows Figure 1 shown.

[0079] Example 2

[0080] (1) A 1 cm × 1 cm sapphire / TiN wafer including a substrate and a bottom electrode was selected as a substrate, and ultrasonically cleaned in acetone, alcohol, and deionized water for 20 min each to remove surface impurities. After cleaning, it was dried with a nitrogen gun for later use;

[0081] (2) Fabrication of the first layer of gallium oxide film on the bottom electrode

[0082] The cleaned substrate was fixed on the mask and placed in a magnetron sputtering apparatus. A 40nm thick gallium oxide film with the same size and shape as the bottom electrode was sputtered on the substrate to form a photoelectric memristor functional layer. The sputtering process conditions were as follows: sputtering power of 110W, sputtering temperature of 20°C, sputtering pressure of 0.6Pa, argon flow rate of 45sccm, oxygen flow rate of 5sccm, sputtering time of 14min, vertical distance between substrate tray and target source of 75mm, vacuum degree of 6x10 -4Pa, the substrate tray rotation speed is 12r / min. It should be noted that the sputtering pressure is adjusted by first increasing the pressure to 1.2Pa with the substrate baffle closed, and then adjusting to 0.6Pa after observing glow discharge in the sputtering chamber. After pre-sputtering for 5min, the substrate baffle is opened to officially start sputtering.

[0083] (3) Preparation of MXene coating layer on the first resistive functional layer

[0084] Place the sample with the gallium oxide film sputtered in step 2 in a UV irradiator for 10 minutes. Then spin-coat the sample with a 2 mg / mL MXene suspension. The spin-coating parameters are: spin-coating speed of 2000 rpm, spin-coating time of 30 seconds, heating temperature after spin-coating of 70°C, and heating time of 20 minutes.

[0085] (4) Preparation of Cu metal particle layer on MXene coating layer

[0086] The sample spin-coated in step 3 was fixed on the mask, placed in a magnetron sputtering instrument, and the process conditions were set as follows: sputtering power of 120 W, sputtering temperature of 20 ° C, sputtering pressure of 0.6 Pa, argon flow rate of 50 sccm, sputtering time of 5 seconds, vertical distance between substrate tray and target source of 75 mm, vacuum degree of 8x10-4 Pa, and substrate tray rotation speed of 10 r / min. The pressure was first increased to 1.2 Pa with the substrate baffle closed, and then adjusted to 0.6 Pa after observing glow discharge in the sputtering chamber. After pre-sputtering for 5 minutes, the substrate baffle was opened and sputtering officially started. A thin layer of Cu that was not enough to form a film was sputtered on the MXene film, so that it naturally formed metal particles according to the island growth mode.

[0087] (5) Growing a second resistive switching functional layer on the Cu metal particle layer

[0088] Same as step 2, the sample after spin coating with Ag nanoparticles was fixed on the mask, placed in a magnetron sputtering instrument, and a 40 nm gallium oxide film was sputtered with the same parameters;

[0089] (6) Preparing a top electrode on the second resistive functional layer

[0090] The gallium oxide film sputtered in step 5 is placed in a vacuum evaporation device, and an Ag electrode with a size of 80 μm×80 μm and a thickness of 120 nm is evaporated on the gallium oxide film to complete the device manufacturing and obtain the gallium oxide resistive random access memory with the MXene-coated metal particles; the process parameters are as follows: the evaporation current is 110 A, the evaporation rate is 0.4 nm / s, and the vacuum degree is 7×10 - 4 Pa, the tray rotates at 12r / min.

[0091] Performance Testing

[0092] The semi-logarithmic current-voltage test was performed on the gallium oxide resistive random access memory of the MXene-coated metal particles described in Example 1 of the present invention. The results are as follows: Figure 3 shown; based on Figure 3 It can be seen that during multiple set-reset cycles, the gallium oxide resistive random access memory with MXene-coated metal particles described in Example 1 can ensure that the set voltage floats within the range of 0.2V to 0.4V, which is very stable.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A gallium oxide resistive random access memory with MXene-coated metal particles, characterized in that: include: Substrate, bottom electrode, first resistive functional layer, MXene coating layer, metal particle layer, second resistive functional layer and top electrode; Wherein, the first resistive switching functional layer and the second resistive switching functional layer are made of gallium oxide; The thickness of the first resistive switching functional layer and the second resistive switching functional layer is 20-30 nm; The MXene coating layer is a MXene film prepared by spin coating.

2. The MXene-coated metal particle gallium oxide resistive random access memory according to claim 1, characterized in that: The substrate is made of SiO2, sapphire or Si.

3. The MXene-coated metal particle gallium oxide resistive random access memory according to claim 1, characterized in that: The bottom electrode is made of any one of Pt, heavily doped Si or TiN, and the thickness of the bottom electrode is 100-150 nm.

4. The MXene-coated metal particle gallium oxide resistive random access memory according to claim 1, characterized in that: The metal particles used in the metal particle layer are any metal that can form nanoparticles, and the particle size of the metal particles is 2-10 nm.

5. The MXene-coated metal particle gallium oxide resistive random access memory according to claim 1, characterized in that: The top electrode is made of active metal material.

6. A method for preparing a gallium oxide resistive random access memory having MXene-coated metal particles according to any one of claims 1 to 5, characterized in that: The following steps are involved: Select a substrate and clean it to obtain a cleaned substrate; Placing the cleaned substrate on a mask and placing it on an electron beam evaporation device to prepare a bottom electrode; Performing a first magnetron sputtering to grow a first gallium oxide film on the bottom electrode to form a first resistive switching functional layer; Preparing a MXene coating layer on the first resistive switching functional layer by spin coating; preparing a metal particle layer on the MXene coating layer; Performing a second magnetron sputtering to grow a second gallium oxide film on the metal particle layer to form a second resistive switching functional layer; A top electrode is evaporated on the second gallium oxide film to obtain the gallium oxide resistive random access memory having the MXene-coated metal particles.

7. The method for preparing the MXene-coated metal particle gallium oxide resistive random access memory according to claim 6, characterized in that: The specific conditions of the first magnetron sputtering and the second magnetron sputtering are: sputtering power of 110-130 W, sputtering temperature of 20° C., sputtering pressure of 0.6 Pa, argon flow rate of 45 sccm, oxygen flow rate of 5 sccm, sputtering time of 7-12 min, vacuum degree of 5×10 -4 ~9×10 -4 Pa, the substrate tray rotates at 10-15 r / min.

8. The method for preparing the MXene-coated metal particle gallium oxide resistive random access memory according to claim 6, characterized in that: The conditions for preparing the MXene coating layer by spin coating are specifically as follows: the concentration of the MXene solution is 2 to 0.5 mg / mL, the spin coating speed is 2000 to 4000 r / min, the spin coating time is 30 s, the heating temperature after spin coating is 70 to 120° C., and the heating time is 8 to 15 min.

9. The method for preparing the MXene-coated metal particle gallium oxide resistive random access memory according to claim 6, characterized in that: The conditions for evaporating the top electrode are as follows: the evaporation current is 100-120A, the evaporation rate is 0.3-0.7nm / s, the vacuum degree is 5×10 -4 ~9×10 -4 Pa, the tray speed is 10~5r / min.

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