A preparation method of an oxide niobium thin film resistive random access memory with an Au nanoparticle modified lower electrode

Abstract

The application belongs to the technical field of semiconductor resistive random access memory (RRAM), and particularly discloses a preparation method of an NbO thin film RRAM with an Au nanoparticle modified lower electrode. The Au nanoparticle modified substrate is prepared in the following manner: a Pt / Ti / SiO2 / Si substrate with a deposited lower electrode Pt is placed in a solution for preparing Au-NPs by using a chemical reduction method and taking tetrachloroauric acid trihydrate as raw material, and after the reaction is completed, the modified Pt / Ti / SiO2 / Si substrate is taken out; NbO x thin film is deposited on the substrate, and then a Pt-Au / NbO x / W needle RRAM is reassembled. It is detected that the voltage distribution of the RRAM prepared by the method is more concentrated, the retention characteristic is more persistent, and the stability is better.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor resistive switching memory technology, specifically relating to a method for preparing a niobium oxide thin film resistive switching memory with Au nanoparticle-modified electrodes. Background Technology

[0002] With the emergence of new technologies such as cloud computing and big data, the scale and complexity of data storage have reached unprecedented heights. Due to the need for high data storage density and the limitations of traditional memory, there is a need for memory based on new structures and mechanisms. Among emerging non-volatile memories, resistive random access memory (RRAM) stands out as an ideal choice for high-density storage due to its high scalability and multi-value storage capabilities. RRAM has a simple electrode / insulator / electrode structure. In the sandwich structure of RRAM, the resistive switching layer is the most important factor determining the properties of RRAM. However, once the resistive switching layer is determined, other factors also have a significant impact on the resistive switching behavior of the device, such as the contact condition at the electrode-resistive switching layer interface.

[0003] Metal nanoparticles have been extensively studied due to their unique electronic structure and nanoscale properties [Zabet-Khosousi A., et al. Charge transport in nanoparticle assemblies[J]. Chemical Reviews, 2008, 108(10):4072-4124; Talapin D V., et al. Prospects of colloidal nanocrystals for electronic and optoelectronic applications[J]. Chemical Reviews, 2010, 110(1):389-458.]. Introducing metal nanoparticles into transition metal oxide RRAMs can significantly improve the on / off ratio, stability, and concentration of transition voltage distribution. Embedded nanoparticles typically possess good conductivity, which can induce the formation of conductive filaments in a fixed location, reducing the random growth of conductive filaments and thus improving the concentration of transition voltage distribution in the RRAM. Among various nanoparticles, Au-NPs have become a focus of research due to their chemical stability, ease of synthesis, and high work function.

[0004] Existing technologies CN102227014A and CN102903847B disclose the influence of metal nanoparticles on the performance of resistive switching memory devices. CN102227014A describes a method involving first depositing a thin film followed by annealing and then stretching an LB film, or employing a chemical dispersion method for metal nanoparticles to distribute nanocrystalline metal grains on the lower electrode, resulting in a lower electrode with a pointed shape. CN102903847B describes applying a forward bias voltage to the lower electrode to ensure that the nanocrystalline particles grow only between the non-depletion region of the N-region and the bottom electrode. These methods either use metal elements that are easily oxidized, or the prepared nanocrystals exhibit high randomness, making it difficult to control the number and size of the nanocrystals. This leads to instability in the size and number of conductive channels, resulting in highly unstable device performance. Furthermore, these methods can only qualitatively assess, not quantitatively determine, the metal nanoparticles obtained and their impact on device performance, and the processes and operations are complex.

[0005] Currently, there are no reported methods for optimizing the resistivity switching behavior of niobium oxide thin films by Au nanoparticle (Au-NPs) modification. This invention studies the regulation of the switching behavior of the electrode on the RRAM of niobium oxide thin films by Au nanoparticle modification, filling the gap in the prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for preparing a niobium oxide thin-film resistive switching memory with Au nanoparticle-modified electrodes.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for fabricating a niobium oxide thin-film resistive switching memory with Au nanoparticle-modified electrodes includes the following steps:

[0009] Step (1) Au-NPs modification of the substrate with the lower electrode deposited: The substrate Pt / Ti / SiO2 / Si with the lower electrode Pt deposited is placed in a solution of Au-NPs prepared by chemical reduction using tetrachloroauric acid trihydrate as raw material. After the reaction is completed, the substrate is removed.

[0010] Step (2), NbO x Thin film preparation: NbO was deposited on Pt / Ti / SiO2 / Si substrates modified with different concentrations of Au-NPs obtained in step (1) by radio frequency magnetron sputtering. x film;

[0011] Step (3), Pt-Au / NbO x Assembly of / W-needle RRAM: The prepared NbOx thin film is assembled into an RRAM. The lower electrode of the device is a Pt electrode, and no additional upper electrode is required. The upper electrode is the W-needle connected during the test.

[0012] Furthermore, in step (1), the Au-NPs modified on the lower electrode surface are polycrystalline, spherical, and have uniform particle size with a particle diameter of 7-10 nm.

[0013] Furthermore, in step (1), the method for preparing the Au-NPs-modified substrate with the lower electrode deposited is as follows:

[0014] First, place a clean Pt / Ti / SiO2 / Si substrate into a round-bottom flask. Measure 80 ml of deionized water into the flask using a graduated cylinder. Place the flask on a magnetic stirrer with heating function and heat to boiling, adjusting the speed to 200 rpm. Weigh out appropriate amounts of sodium citrate and tetrachloroauric acid trihydrate and quickly add them to the boiling water, continuing stirring. Set the heating temperature to 120℃ and the reaction time to 30 min. After the reaction is complete, remove the substrate and rinse it several times with running deionized water to remove excess Au-containing contaminants from the surface. 3+ The solution was prepared by drying the rinsed substrate in an oven at 60°C for 6 hours for later use.

[0015] Simultaneously, the remaining purple-red solution after the reaction in the above preparation method is centrifuged, and the precipitate is washed with deionized water and centrifuged twice. Finally, the solution containing Au-NPs is dispersed in deionized water. This step is mainly used to remove residual organic matter and impurity ions in the solution, which facilitates the subsequent observation of the shape and particle size of the prepared Au-NPs by transmission electron microscopy.

[0016] Further, in step (1), the appropriate amount is Au. min Sodium citrate 0.048g and tetrachloroauric acid trihydrate 0.0052g; Au med Sodium citrate 0.0815g and tetrachloroauric acid trihydrate 0.014g; Au max Sodium citrate 0.163g and tetrachloroauric acid trihydrate 0.02752g. Au min Au med Au max These represent low-concentration Au-NPs, medium-concentration Au-NPs, and high-concentration Au-NPs, respectively. Accordingly, the lower electrode Pt on the substrate obtained in step (1), modified with different concentrations of Au-NPs, are respectively Pt-Au min Pt-Au med Pt-Au max .

[0017] Furthermore, in step (2), NbO x The film thickness is 100-120 nm; for NbO deposited on the substrate xThe thin film underwent XPS testing (as shown in the attached diagram in the instruction manual). Figure 2 From this, we can know that the deposited NbO x The thin film is Nb2O 5-x film.

[0018] Furthermore, in step (2), NbO is deposited by radio frequency magnetron sputtering. x The film was deposited at room temperature.

[0019] The assembled niobium oxide thin film resistive switching memory (Pt-Au / NbO) x When performing electrical property tests on the NbO ( / W needle RRAM), x A limiting current of 5mA was applied to the thin film, a bias voltage was applied to the W needle, and the Pt electrode was grounded. The applied scanning voltage sequence was 0→2.5V→0→-1.5V→0. Testing showed that the Pt-Au... min / NbO x / W pin RRAM V set The distribution becomes more concentrated, V reset The effect was significantly reduced and the distribution range was narrower, with the retention time increasing to 2.5 × 10⁻⁶. 4 There was no attenuation in s, and the resistance distributions of HRS and LRS of the device modified with Au-NPs became more stable.

[0020] This invention was completed with the support of the National Natural Science Foundation of China (Project No. 12074291) and the Hubei Provincial Science and Technology Program (Project No. 2022AEA001).

[0021] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0022] 1. The method of the present invention is simple and easy to operate, and the synthesis size of Au-NPs can be easily controlled.

[0023] 2. Nb2O deposited on substrates with different concentrations of Au-NPs 5-x The only difference between the thin films and the original films lies in the concentration of Au-NPs attached to the substrate; the Au-NPs are dispersed on the Pt electrode, rather than embedded in the NbO. x In thin films, different concentrations of Au-NPs only modify the morphology of the Pt lower electrode, altering the contact between the lower electrode and the thin film, without changing the composition and properties of the thin film.

[0024] 3. According to general technical knowledge, the modification of the lower electrode by Au-NPs may have two effects: First, NbO xThe microstructure of the thin film may be altered; secondly, Au-NPs can serve as an extension of the Pt electrode. In this invention, the thin film is prepared at room temperature, below that of NbO. x The crystallization temperature of the thin film, therefore the NbO prepared x The thin film is amorphous with a thickness of 100-120 nm, while the Au-NPs attached to the substrate have a particle size of approximately 7-10 nm. The Au-NPs deposited on the substrate can be completely absorbed by NbO. x Thin film coverage, therefore, Au-NPs will not affect NbO. x The film morphology is affected. In this invention, Au-NPs mainly serve as an extension of the Pt electrode.

[0025] 4. Pt-Au obtained using the method of this invention min / NbO x / W tip Niobium oxide thin film resistive switching memory V reset The average voltage is -0.59V, and the cumulative frequency is distributed in the range of -0.74V to -0.44V for 20% to 80% of the time. Device V reset The distribution interval is reduced and the distribution range is narrower; Device V set The distribution dispersion decreased to 19.99%, and the Au-NPs modified device V set Becoming more concentrated, V reset The voltage is reduced and the voltage distribution range is narrowed. The device cycle life can also reach 350 cycles, and the HRS resistance value after stabilization is approximately 7 × 10⁻⁶. 4 The LRS resistance distribution of the device is relatively stable without significant change, ranging from 40Ω to 80Ω, and the on / off ratio is approximately 1000. Au-NPs-modified devices further stabilize the HRS and LRS resistance distributions. The hold time of the device can reach 2.5 × 10⁻⁶. 4 The current value of the device's HRS was relatively stable throughout the test.

[0026] 5. Au-NP modification does not affect the device's conductivity mechanism. The conductivity mechanisms at HRS and LRS are the defect-controlled SCLC mechanism and the ohmic conductivity mechanism, respectively. When the Au-NP modification concentration is low, conductive filaments grow more easily along Au-NPs, thus reducing the randomness of filament growth and ultimately improving device stability and the concentration of transition voltage distribution. In contrast, when the Au-NP modification concentration is too high, cross-connections may occur between different conductive filaments, leading to a high degree of randomness in the formation and breakage of conductive filaments. Therefore, higher Au-NP modification concentrations result in Pt-Au / NbO x Devices such as / W tip exhibited higher voltage variability in their switching voltage. Attached Figure Description

[0027] Figure 1 (a) is a transmission electron microscope image of the Au nanoparticles prepared in Example 2. As can be seen from the image, the Au nanoparticles are spherical with a diameter of about 7-10 nm. (b) is a substrate on which the Au nanoparticles prepared in Example 2 are attached. As can be seen from the image, the Au nanoparticles are scattered on the substrate in groups of two or three. (c) is a thickness diagram of the niobium oxide film deposited on the substrate on which the Au nanoparticles are attached in Example 2. As can be seen from the image, the thickness of the niobium oxide film is about 110-120 nm.

[0028] Figure 2 NbO deposited on different substrates x XPS spectra of Nb, O, and Au core levels in thin films: (a, b) clean substrate, (c, d, e) Au max Substrate, (f) NbO deposited on different substrates x XPS spectrum of the thin film, with the inset showing a magnified view of the area within the orange box.

[0029] Figure 3 (a) Pt / NbO corresponding to the niobium oxide thin film deposited on the clean substrate prepared in Example 1. x (a) IV diagram of the / W tip device; (b) Pt-Au corresponding to the niobium oxide thin film deposited on the Au nanoparticle-modified substrate prepared in Example 2. min / NbO x / W tip device IV diagram; from the diagram, it can be seen that Pt-Au min / NbO x / W needle device V set Becoming more concentrated, V reset (c) The voltage distribution range is narrowed and the voltage is reduced; (d) Pt-Au film corresponding to the niobium oxide film deposited on the Au nanoparticle-modified substrate prepared in Comparative Example 1. med / NbO x / W needle device IV image; (d) is the Pt-Au corresponding to the niobium oxide thin film deposited on the Au nanoparticle-modified substrate prepared in Comparative Example 2. max / NbO x / W pin device IV diagram.

[0030] Figure 4 (a) Pt / NbO corresponding to the niobium oxide thin film deposited on the clean substrate prepared in Example 1. x / W tip device V set and V reset (a) Cumulative frequency distribution diagram; (b) Pt-Au corresponding to the niobium oxide thin film deposited on the Au nanoparticle-modified substrate prepared in Example 2. min / NbO x / W needle device V set and V reset The cumulative frequency distribution plot shows that σ is the standard deviation, μ is the mean, and σ / μ is the coefficient of variation, representing the dispersion of the data. This coefficient can be used to indicate the central tendency of the voltage distribution. From the plot, we can see that Pt-Au... min / NbO x The SET voltage distribution of the / W tip device is more concentrated; (c) shows the Pt-Au film deposited on the Au nanoparticle-modified substrate prepared in Comparative Example 1. med / NbO x / W needle device V set and V reset Cumulative frequency distribution diagram; (d) shows the Pt-Au film deposited on the Au nanoparticle-modified substrate prepared in Comparative Example 2. max / NbO x / W needle device V set and V reset Cumulative frequency distribution diagram.

[0031] Figure 5 (a) Pt / NbO corresponding to the niobium oxide thin film deposited on the clean substrate prepared in Example 1. x The tolerance of / W tip devices, (b) is the Pt-Au corresponding to the niobium oxide thin film deposited on the Au nanoparticle-modified substrate prepared in Example 2. min / NbO x The tolerance of the / W needle device can be seen from the figure, Pt-Au min / NbO x / W needle devices have a higher cycle tolerance and more stable HRS and LRS resistance distributions; (c) shows the Pt-Au thin film deposited on the Au nanoparticle-modified substrate prepared in Comparative Example 1. med / NbO x / W needle device tolerance; (d) is the Pt-Au corresponding to the niobium oxide thin film deposited on the Au nanoparticle-modified substrate prepared in Comparative Example 2. max / NbO x / W needle device tolerance.

[0032] Figure 6 (a) Pt / NbO corresponding to the niobium oxide thin film deposited on the clean substrate prepared in Example 1. x (a) Retention characteristics of the / Wtip device; (b) Pt-Au corresponding to the niobium oxide film deposited on the Au nanoparticle-modified substrate prepared in Example 2. min / NbO x The retention characteristic diagram of the / W needle device shows that Pt-Aumin / NbO x / W needle devices exhibit better retention characteristics; (c) shows the Pt-Au thin film deposited on the Au nanoparticle-modified substrate prepared in Comparative Example 1. med / NbO x / W needle device retention characteristics diagram; (d) is the Pt-Au corresponding to the niobium oxide thin film deposited on the Au nanoparticle modified substrate prepared in Comparative Example 2. max / NbO x Retention characteristics diagram of / W pin device. Detailed Implementation

[0033] The technical solution of the present invention will now be described in detail with reference to specific embodiments and the accompanying drawings.

[0034] The substrate used in the following embodiments is a Pt / Ti / SiO2 / Si substrate, specifically a Pt(111) / Ti / SiO2 / Si(100) substrate purchased from Hefei Yuanjing Technology Materials Co., Ltd., with film thicknesses of: Pt(111) layer: 150nm; Ti layer: 20nm; SiO2 layer: 300nm; Si layer: 0.525mm. After cutting, the substrate used in the following embodiments has dimensions of 1cm in length × 1cm in width.

[0035] The Nb2O5 ceramic target material used was purchased from Beijing Gaodewei Metal Technology Development Co., Ltd., with a purity of 99.99% and dimensions of 50.8 mm in diameter and 3 mm in thickness.

[0036] Example 1

[0037] Niobium oxide films were deposited on clean substrates without Au-NPs modification, and Pt / NbO were assembled. x The fabrication method of the / W pin resistive switching memory is as follows.

[0038] Step (1): Deposit NbO on a clean substrate x Thin film: NbO was deposited using radio frequency magnetron sputtering. x Thin film deposition was performed at room temperature, with a deposition power of 20 W and a deposition time of 20 min.

[0039] Step (2), Pt / NbO x Assembly of / W needle RRAM: The prepared NbO x The thin film is assembled into an RRAM, and the lower electrode of the device is a Pt electrode, eliminating the need for additional deposition of the upper electrode. The upper electrode is the W pin used for testing during the testing process.

[0040] For the above-assembled Pt / NbO x Electrical properties tests were performed on the NbO-N- ... xA limiting current of 5mA is applied to the thin film, a bias voltage is applied to the W-pin, and the Pt electrode is grounded. The applied scanning voltage sequence is 0→2.5V→0→-1.5V→0. The device's IV plot, voltage accumulation probability distribution plot, cycle tolerance, and retention characteristics are shown below. Figure 3-6 As shown.

[0041] Example 2

[0042] The fabrication method of niobium oxide thin film resistive switching memory with Au nanoparticle-modified electrodes is as follows.

[0043] Step (1), Preparation of Au-NPs modified Pt / Ti / SiO2 / Si substrate: First, place the clean Pt / Ti / SiO2 / Si substrate into a round-bottom flask. Measure 80 ml of deionized water into the round-bottom flask using a graduated cylinder. Place the round-bottom flask on a magnetic stirrer with heating function and heat to boiling, adjusting the speed to 200 r / min. Weigh 0.048 g of sodium citrate and 0.0052 g of tetrachloroauric acid trihydrate and quickly add them to the boiling water while continuing to stir. Set the heating temperature to 120℃ and the reaction time to 30 min. After the reaction is complete, remove the substrate and rinse it several times with running deionized water to remove excess Au-containing substances adhering to the surface. 3+ The solution was prepared by drying the rinsed substrate in an oven at 60°C for 6 hours for later use.

[0044] Step (2), NbO x Thin film preparation: NbO was deposited on the Au-NPs modified Pt / Ti / SiO2 / Si substrate obtained in step (1) by radio frequency magnetron sputtering. x Thin film deposition was performed at room temperature, with a deposition power of 20 W and a deposition time of 20 min.

[0045] Step (3), Pt-Au min / NbO x Assembly of / W-pin RRAM: The NbO obtained in step (2) is used to assemble the RRAM. x The thin film is assembled into an RRAM. The lower electrode of the device is a Pt electrode modified with Au-NPs, eliminating the need for additional deposition of the upper electrode. The upper electrode is the W pin used for testing during the testing process.

[0046] The above content contains Pt-Au min This refers to a Pt electrode modified with gold nanoparticles, Au min This refers to the concentration of Au nanoparticles obtained from the complete reaction in step (1) in 80 ml of solution being 0.165 mmol / L (theoretical calculation value, the same in subsequent examples).

[0047] Centrifuge the remaining purple-red solution after the reaction in step (1). Wash the precipitate with deionized water and centrifuge twice. Finally, disperse the Au-NPs-containing solution in deionized water to facilitate subsequent transmission electron microscopy observation of the shape and particle size of the prepared Au-NPs. (See attached instruction manual.) Figure 1 As shown, Au-NPs are spherical with uniform particle size, and the particle diameter is approximately 10 nm. In step (2), NbO... x The film thickness is 117 nm; for NbO deposited on the substrate x The thin film underwent XPS testing (as shown in the attached diagram in the instruction manual). Figure 2 From this, we can know that the deposited NbO x The thin film is Nb2O 5-x film.

[0048] Similar to Example 1, the above-assembled Pt-Au min / NbO x Electrical properties tests were performed on the NbO-N- ... x A limiting current of 5mA was applied to the thin film. During testing, a bias voltage was applied to the W electrode, and the Pt electrode was grounded. The applied scanning voltage sequence was 0→2.5V→0→-1.5V→0. The device's IV plot, voltage cumulative probability distribution plot, cycle withstand, and retention characteristic plots are shown below. Figure 3-6 As shown. Experimental results revealed that Pt-Au min / NbO x / Wtip device V reset The average voltage is -0.59V, and the cumulative frequency is distributed in the range of -0.74V to -0.44V for 20% to 80% of the time. Device V reset The distribution interval is reduced and the distribution range is narrower; Device V set The distribution dispersion decreased to 19.99%, and the Au-NPs modified device V set Becoming more concentrated, V reset The voltage is reduced and the voltage distribution range is narrowed. The device cycle life can also reach 350 cycles, and the HRS resistance value after stabilization is approximately 7 × 10⁻⁶. 4 The LRS resistance distribution of the device is relatively stable without significant change, ranging from 40Ω to 80Ω, and the on / off ratio is approximately 1000. Au-NPs-modified devices further stabilize the HRS and LRS resistance distributions, and the device's V... set The distribution becomes more concentrated, V reset The effect was significantly reduced and the distribution range was narrower, with the retention time increasing to 2.5 × 10⁻⁶. 4 s did not decay.

[0049] Comparative Example 1

[0050] The fabrication method of niobium oxide thin film resistive switching memory with Au nanoparticle-modified electrodes is as follows.

[0051] Step (1), Preparation of Au-NPs modified Pt / Ti / SiO2 / Si substrate: First, place the clean Pt / Ti / SiO2 / Si substrate into a round-bottom flask. Measure 80 ml of deionized water into the round-bottom flask using a graduated cylinder. Place the round-bottom flask on a magnetic stirrer with heating function and heat to boiling, adjusting the speed to 200 r / min. Weigh 0.0815 g of sodium citrate and 0.014 g of tetrachloroauric acid trihydrate and quickly add them to the boiling water while continuing to stir. Set the heating temperature to 120℃ and the reaction time to 30 min. After the reaction is complete, remove the substrate and rinse it several times with running deionized water to remove excess Au-containing substances adhering to the surface. 3+ The solution was prepared by drying the rinsed substrate in an oven at 60°C for 6 hours for later use.

[0052] Step (2), NbO x Thin film preparation: NbO was deposited on the Au-NPs modified Pt / Ti / SiO2 / Si substrate obtained in step (1) by radio frequency magnetron sputtering. x Thin film deposition was performed at room temperature, with a deposition power of 20 W and a deposition time of 20 min.

[0053] Step (3), Pt-Au med / NbO x Assembly of / W-pin RRAM: The NbO obtained in step (2) is used to assemble the RRAM. x The thin film is assembled into an RRAM. The lower electrode of the device is a Pt electrode modified with Au-NPs, eliminating the need for additional deposition of the upper electrode. The upper electrode is the W pin used for testing during the testing process.

[0054] The above content contains Pt-Au med This refers to a Pt electrode modified with gold nanoparticles, Au med This means that the concentration of Au nanoparticles obtained from the complete reaction in step (1) is 0.444 mmol / L in 80 ml of solution.

[0055] Centrifuge the remaining purple-red solution after the reaction in step (1). Wash the precipitate with deionized water and centrifuge twice. Finally, disperse the Au-NPs solution in deionized water to facilitate subsequent transmission electron microscopy observation of the shape and particle size of the prepared Au-NPs. The Au-NPs are spherical with uniform particle size, with a particle diameter of approximately 10 nm. NbO x The film thickness is 106 nm; for NbO deposited on the substrate x The thin film underwent XPS testing (as shown in the attached diagram in the instruction manual). Figure 2 From this, we can know that the deposited NbOx The thin film is Nb2O 5-x film.

[0056] Similarly, for the Pt-Au assembled above med / NbO x Electrical properties tests were performed on the NbO-N- ... x A limiting current of 5mA was applied to the thin film. During testing, a bias voltage was applied to the W electrode, and the Pt electrode was grounded. The applied scanning voltage sequence was 0→2.5V→0→-1.5V→0. The device's IV plot, voltage cumulative probability distribution plot, cycle withstand, and retention characteristic plots are shown below. Figure 3-6 As shown.

[0057] Comparative Example 2

[0058] The fabrication method of niobium oxide thin film resistive switching memory with Au nanoparticle-modified electrodes is as follows.

[0059] Step (1), Preparation of Au-NPs modified Pt / Ti / SiO2 / Si substrate: First, place the clean Pt / Ti / SiO2 / Si substrate into a round-bottom flask. Measure 80 ml of deionized water into the round-bottom flask using a graduated cylinder. Place the round-bottom flask on a magnetic stirrer with heating function and heat to boiling, adjusting the speed to 200 r / min. Weigh 0.163 g of sodium citrate and 0.02752 g of tetrachloroauric acid trihydrate and quickly add them to the boiling water while continuing to stir. Set the heating temperature to 120℃ and the reaction time to 30 min. After the reaction is complete, remove the substrate and rinse it several times with running deionized water to remove excess Au-containing substances adhering to the surface. 3+ The solution was prepared by drying the rinsed substrate in an oven at 60°C for 6 hours for later use.

[0060] Step (2), NbO x Thin film preparation: NbO was deposited on the Au-NPs modified Pt / Ti / SiO2 / Si substrate obtained in step (1) by radio frequency magnetron sputtering. x Thin film deposition was performed at room temperature, with a deposition power of 20 W and a deposition time of 20 min.

[0061] Step (3), Pt-Au max / NbO x Assembly of / W-pin RRAM: The NbO obtained in step (2) is used to assemble the RRAM. x The thin film is assembled into an RRAM. The lower electrode of the device is a Pt electrode modified with Au-NPs, eliminating the need for additional deposition of the upper electrode. The upper electrode is the W pin used for testing during the testing process.

[0062] The above content contains Pt-Au max This refers to a Pt electrode modified with gold nanoparticles, Aumax This means that the concentration of Au nanoparticles obtained from the complete reaction in step (1) is 0.874 mmol / L in 80 ml of solution.

[0063] Centrifuge the remaining purple-red solution after the reaction in step (1). Wash the precipitate with deionized water and centrifuge twice. Finally, disperse the Au-NPs solution in deionized water to facilitate subsequent transmission electron microscopy observation of the shape and particle size of the prepared Au-NPs. The Au-NPs are spherical with uniform particle size, with a particle diameter of approximately 10 nm. NbO x The film thickness is 113 nm; for NbO deposited on the substrate x The thin film underwent XPS testing (as shown in the attached diagram in the instruction manual). Figure 2 From this, we can know that the deposited NbO x The thin film is Nb2O 5-x film.

[0064] Similarly, for the Pt-Au assembled above max / NbO x Electrical properties tests were performed on the NbO-N- ... x A limiting current of 5mA was applied to the thin film. During testing, a bias voltage was applied to the W electrode, and the Pt electrode was grounded. The applied scanning voltage sequence was 0→2.5V→0→-1.5V→0. The device's IV plot, voltage cumulative probability distribution plot, cycle withstand, and retention characteristic plots are shown below. Figure 3-6 As shown.

[0065] Comparing the characterization and test results of Examples 1-2 and Comparative Examples 1-2, it can be seen that: NbO can be deposited on Pt / Ti / SiO2 / Si substrates modified with different concentrations of Au-NPs using radio frequency magnetron sputtering. x Thin film, NbO x Parameters such as power, pressure, and temperature were kept constant during the thin film deposition process to ensure the formation of the prepared NbO. x With essentially the same film composition and thickness, the effect of different bottom electrode morphologies on RRAM switching performance was investigated by varying the Au-NP modification concentration. TEM analysis revealed that Au-NPs of different concentrations had uniform diameters (around 10 nm), and XPS analysis showed that NbO deposited on different substrates... x The thin films are all Nb 5+ Pt layers modified with Au-NPs at different concentrations were used as the lower electrode, and NbO was used as the lower electrode. x The thin film serves as the resistive switching layer, and the W needle used in the test acts as the top electrode, assembled into a Pt-Au / NbO layer. x / W needle damping memory. Pt-Au / NbO modified with different concentrations of Au-NPs. xIV testing of the / W needle damping memory revealed that, compared to Pt / NbO x / W needle damping memory, Pt-Au formed by minimum concentration of Au-NPs modification. min / NbO x The / W needle device has the most superior properties: the device's V set The distribution becomes more concentrated, V reset The effect was significantly reduced and the distribution range was narrower, with the retention time increasing to 2.5 × 10⁻⁶. 4 No attenuation was observed, and the resistance distributions of the HRS and LRS of the Au-NPs-modified device became more stable. Analysis of the device's conduction mechanism revealed that Au-NPs modification did not affect the device's conduction mechanism; the device exhibited a defect-controlled SCLC mechanism in HRS and an ohmic mechanism in LRS. When the Au-NPs modification concentration was low, i.e., Pt-Au... min / NbO x The conductive filaments in the / W needle device grow locally at fixed locations, reducing the randomness of filament growth and improving the uniformity and stability of the device's switching voltage. However, when the Au-NPs modification concentration is too high, cross-connections may occur between different conductive filaments, leading to a high degree of randomness in the formation and breakage of the conductive filaments. Therefore, Pt-Au max / NbO x The switching voltage of the / W needle device exhibited greater dispersion. Therefore, an appropriate concentration of Au-NPs can be used to modify the electrode to improve the NbO content. x RRAM switching voltage concentration and device stability.

[0066] The above description is only a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for fabricating a niobium oxide thin-film resistive switching memory with Au nanoparticle-modified electrodes, characterized in that, Includes the following steps: Step (1) Preparation of Au-NPs modified Pt / Ti / SiO2 / Si substrate: First, place the clean Pt / Ti / SiO2 / Si substrate into a round-bottom flask, measure 80 ml of deionized water into the round-bottom flask using a graduated cylinder, place the round-bottom flask on a magnetic stirrer with heating function and heat to boiling, adjusting the speed to 200 r / min; weigh 0.048 g of sodium citrate and 0.0052 g of tetrachloroauric acid trihydrate and quickly add them to the boiling water and continue stirring, setting the heating temperature to 120℃ and the reaction time to 30 min; the concentration of Au nanoparticles obtained after complete reaction in 80 ml of solution is 0.165 mmol / L; after the reaction is completed, take out the substrate and rinse the substrate several times with running deionized water to remove excess Au-containing substances adhering to the surface. 3+ The solution was prepared by drying the rinsed substrate in an oven at 60°C for 6 hours. The Au nanoparticles modified on the surface of the lower electrode were polycrystalline, spherical, and uniform in size, with a particle diameter of 10 nm. Step (2), NbO x Thin film preparation: NbO was deposited on the Au-NPs modified Pt / Ti / SiO2 / Si substrate obtained in step (1) by radio frequency magnetron sputtering. x Thin film, deposition temperature was room temperature, deposition power was 20 W, deposition time was 20 min; the obtained NbO x The thickness of the thin film is 117 nm; Step (3), Pt-Au max / NbO x Assembly of / W-pin RRAM: The NbO obtained in step (2) is used to assemble the RRAM. x The thin film is assembled into an RRAM. The lower electrode of the device is a Pt electrode modified with Au-NPs, eliminating the need for additional deposition of the upper electrode. The upper electrode is the W pin used for testing during the testing process.

2. The preparation method according to claim 1, characterized in that, In step (2), the deposited NbO x XPS testing of the thin film revealed the deposited NbO. x The thin film is Nb2O 5-x film.

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