Method for treating niobium oxide gated tube by supercritical fluid using hydrogen peroxide as reactant

Abstract

The present invention provides a method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, comprising the following steps: placing the niobium oxide gated tube in a reaction chamber, adding water and hydrogen peroxide into the reaction chamber; introducing supercritical carbon dioxide fluid into the reaction chamber, controlling the pressure in the reaction chamber to be 2800 - 3200 psi, the temperature to be 110 - 130 °C, and the reaction time to be 1 - 2 h. The method of the present invention adopts the supercritical carbon dioxide fluid technology, uses hydrogen peroxide and deionized water together as reactive substances to treat the pre-prepared titanium-doped niobium oxide gated tube, successfully reducing the OFF-state current of the device and greatly improving the gating ratio. Since hydrogen peroxide has better oxidizing property than deionized water, using hydrogen peroxide and deionized water together as reactive substances can better passivate the defects inside the material and the device as well as at the interfaces between different materials compared to using deionized water alone as the reaction substance.

Description

Technical Field

[0001] The present invention relates to the technical field of niobium oxide gated tube processing, and particularly to a method for processing niobium oxide gated tubes by supercritical fluid using hydrogen peroxide as a reactant. Background Art

[0002] With the development of information technology, the requirements for information storage capacity are also getting higher and higher. In order to increase the density of memories, the size of devices is continuously reduced. Gated tubes based on the Metal Insulator Transition (MIT) effect have attracted extensive attention due to their simple material composition and easy preparation. For MIT-type gated tubes, gated tubes based on titanium-doped NbO x exhibit a series of advantages such as Forming-free, ultra-high drive current, self-limiting current, and excellent transition voltage consistency. However, it has the disadvantages of a relatively large OFF-state current and a relatively small gate ratio, which is not conducive to suppressing crosstalk current in the memory array and is also not conducive to improving the read margin of memories in the array. Therefore, for titanium-doped NbOx gated tubes, it is still necessary to further optimize their performance to better apply them to three-dimensional memories.

[0003] Currently, thermal annealing treatment (TAT) is a common heat treatment method in thin film preparation processes. The annealing process can effectively improve the defects of thin films and make the structure of thin films more uniform and dense, thereby improving the performance of devices in various aspects. However, a relatively high annealing temperature (about 1000 °C) will introduce some additional problems, such as heat balance, impurity (or dopant) diffusion, deformation caused by thermal stress, etc. Most importantly, TAT is difficult to apply in the back-end processes of integrated circuit processes.

[0004] In addition, from the material perspective, seeking and using high-k materials with a large dielectric constant as the intermediate functional layer of devices. High-k functional layers have been adopted to ensure the reduction of the functional layer thickness. It has become increasingly difficult to use high-k materials to meet the continuous reduction of EOT, and the benefits are also decreasing. At the same time, high-k materials will lead to a relatively high interface state density and a reduction in mobility and reliability, which is also a problem that needs to be solved.

[0005] Based on the defects of current titanium-doped NbOx gated tubes, it is necessary to improve them. Summary of the Invention

[0006] In view of this, the present invention proposes a method for processing niobium oxide gated tubes by supercritical fluid using hydrogen peroxide as a reactant, which solves or at least partially solves the technical defects existing in the prior art.

[0007] In a first aspect, the present invention provides a method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, comprising the following steps:

[0008] Place the niobium oxide gated tube in a reaction chamber, and add 450 - 500 μL of water and 10 - 50 μL of hydrogen peroxide with a mass concentration of 25 - 35% into the reaction chamber;

[0009] Introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 2800 - 3200 psi, the temperature to be 110 - 130 °C, and the reaction time to be 1 - 2 h.

[0010] Preferably, in the method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, place the niobium oxide gated tube in a reaction chamber, and add 500 μL of water and 10 - 50 μL of hydrogen peroxide with a mass concentration of 30% into the reaction chamber.

[0011] Preferably, in the method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, add 500 μL of water and 40 μL of hydrogen peroxide with a mass concentration of 30% into the reaction chamber; introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 3000 psi, the temperature to be 120 °C, and the reaction time to be 1.5 h.

[0012] Preferably, in the method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, the niobium oxide gated tube comprises:

[0013] A bottom electrode;

[0014] A conversion layer, which is located on one side of the bottom electrode;

[0015] A top electrode, which is located on the side of the conversion layer away from the bottom electrode;

[0016] Wherein, the material of the conversion layer is titanium-doped niobium oxide.

[0017] Preferably, in the method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, the material of the bottom electrode is one of Ti, Pt, W or TiN; the material of the top electrode is one of Pt or Ti.

[0018] The method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant according to the present invention has the following beneficial effects compared with the prior art:

[0019] (1) The method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant of the present invention adopts the supercritical carbon dioxide fluid technology, uses hydrogen peroxide and deionized water together as reactive substances, treats the prepared titanium-doped niobium oxide gated tube, successfully reduces the OFF-state current of the device, and greatly improves the gating ratio, providing strong support for the further integration and application of the device. Since hydrogen peroxide has better oxidizing property than deionized water, compared with using deionized water alone as a reaction substance, using hydrogen peroxide and deionized water together as reactive substances can better passivate the defects inside the material and the device as well as at the interfaces of different materials;

[0020] (2) In the method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant of the present invention, when the content of hydrogen peroxide increases from 10 μL to 40 μL, the gating ratio reaches a maximum value of 10 5 , and when the content of hydrogen peroxide continues to increase to 50 μL, the gating ratio decreases. From this, it can be known that for the niobium oxide gated tube device, at a reaction chamber temperature of 120 °C, a pressure of 3000 Psi, adding 40 μL of hydrogen peroxide with a mass concentration of 30% and 500 μL of deionized water as reactive substances and reacting for 1.5 h, the performance optimization effect of the niobium oxide gated tube device is the best, and this set of conditions is the optimal reaction conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is a schematic structural diagram of the niobium oxide gated tube of the present invention;

[0023] Figure 2 is a cross-sectional SEM image of the niobium oxide gated tube prepared in Example 1 of the present invention;

[0024] Figure 3 is an I-V characteristic curve graph of the niobium oxide gated tube not treated by supercritical fluid in Comparative Example 1;

[0025] Figure 4 is an I-V characteristic curve graph of the niobium oxide gated tube treated according to the method in Comparative Example 1;

[0026] Figure 5 is an I-V characteristic curve graph of the niobium oxide gated tube treated according to the method in Comparative Example 2;

[0027] Figure 6 The I-V characteristic curve diagram after processing the niobium oxide gated tube according to the method in Comparative Example 3;

[0028] Figure 7 The I-V characteristic curve diagram after processing the niobium oxide gated tube according to the method in Example 1;

[0029] Figure 8 The I-V characteristic curve diagram after processing the niobium oxide gated tube according to the method in Example 2;

[0030] Figure 9 The I-V characteristic curve diagram after processing the niobium oxide gated tube according to the method in Example 3;

[0031] Figure 10 The I-V characteristic curve diagram after processing the niobium oxide gated tube according to the method in Example 4;

[0032] Figure 11 The I-V characteristic curve diagram after processing the niobium oxide gated tube according to the method in Example 5;

[0033] Figure 12 The graph of the gating ratio after processing the niobium oxide gated tube according to the methods in Examples 1 to 5;

[0034] Figure 13 The I-V characteristic curve and the Forming process curve diagram after processing the niobium oxide gated tube according to the method in Example 4;

[0035] Figure 14 The comparison diagram of the OFF-state current before and after processing the niobium oxide gated tube according to the method in Example 4 and the gated tube of the device;

[0036] Figure 15 The cumulative distribution diagram of the transition voltage in 100 I-V cycles after processing the niobium oxide gated tube according to the method in Example 4;

[0037] Figure 16 The distribution diagram of the ON-state current and the OFF-state current in 100 I-V cycles after processing the niobium oxide gated tube according to the method in Example 4. Detailed implementation manners

[0038] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] The present invention provides a method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, comprising the following steps:

[0040] S1. Place the niobium oxide gated tube in a reaction chamber, and add 450 - 500 μL of water and 10 - 50 μL of hydrogen peroxide with a mass concentration of 25 - 35% into the reaction chamber;

[0041] S2. Introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 2800 - 3200 psi, the temperature to be 110 - 130 °C, and the reaction time to be 1 - 2 h.

[0042] It should be noted that in the method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant in this application, the supercritical carbon dioxide fluid technology (SCCO 2 ) is adopted, and hydrogen peroxide and deionized water are used together as reactive substances to treat the prepared titanium-doped niobium oxide gated tube, successfully reducing the OFF-state current of the device and greatly improving the gate ratio, providing strong support for the further integration and application of the device. Since hydrogen peroxide has better oxidizing property than deionized water, compared with using deionized water alone as a reaction substance, using hydrogen peroxide and deionized water together as reactive substances can better passivate the defects inside the material and the device and at the interfaces of different materials.

[0043] Specifically, when the temperature and pressure of carbon dioxide reach above a certain critical point, it will turn into a supercritical state, having properties different from those of substances in the traditional solid, liquid or gaseous states. For the density, viscosity (cP) and diffusion coefficient (cm 2 / s) of supercritical carbon dioxide, they are all between those of liquids and gases, and it is a special material state between liquids and gases. In addition, supercritical carbon dioxide has almost no surface tension and has the advantages of high liquid solubility and high gas permeability. The effective reactive substances water and hydrogen peroxide are carried into the device by the supercritical fluid, thereby effectively passivating the interface defects.

[0044] In some embodiments, place the niobium oxide gated tube in a reaction chamber, and add 500 μL of water and 10 - 50 μL of hydrogen peroxide with a mass concentration of 30% into the reaction chamber.

[0045] In some embodiments, add 500 μL of water and 40 μL of hydrogen peroxide with a mass concentration of 30% into the reaction chamber; introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 3000 psi, the temperature to be 120 °C, and the reaction time to be 1.5 h.

[0046] During the supercritical fluid treatment process, the addition amounts of water and hydrogen peroxide into the reaction cavity both have a great influence on the performance of the niobium oxide gated tube after supercritical treatment. When the addition amount of water is 500 μL, the addition amount of hydrogen peroxide is 40 μL, the pressure is 3000 psi, the temperature is 120 °C, and the reaction time is 1.5 h, it is the optimal reaction process.

[0047] Specifically, the reaction cavity is a cavity resistant to high pressure, high temperature, and corrosion. For example, it can be a special cavity with an air inlet and a liquid inlet and capable of being heated. Through the air inlet, supercritical carbon dioxide fluid can be introduced into the reaction cavity, and through the liquid inlet, water and hydrogen peroxide can be added into the reaction cavity. At the same time, the cavity can be heated to reach the reaction temperature.

[0048] Specifically, in the embodiments of the present application, the pressure in the reaction cavity can be made 3000 psi through the following method:

[0049] Provide a gas storage cylinder storing carbon dioxide. The gas storage cylinder is connected to the air inlet on the reaction cavity through a pipeline. At the same time, a high-pressure injection pump is also provided on the pipeline. The carbon dioxide fluid in the gas storage cylinder is compressed by the high-pressure injection pump and then pumped into the reaction cavity to make the pressure in the reaction cavity 3000 psi.

[0050] Specifically, in some embodiments, before adding water and hydrogen peroxide into the reaction cavity, the reaction cavity is also cleaned with absolute ethanol and then dried. At the same time, a quartz bracket is provided. The quartz bracket is used to fix the niobium oxide gated tube. Before the supercritical fluid treatment of the niobium oxide gated tube, the quartz bracket is also immersed in ethanol and ultrasonically oscillated to remove impurities and organic pollutants on the quartz bracket. After the cleaning is completed, the quartz bracket is dried, and then the niobium oxide gated tube is fixed on the quartz bracket and placed in the reaction cavity for supercritical fluid treatment.

[0051] It should be noted that in the present application, water and hydrogen peroxide are added to the bottom of the reaction cavity, and it is not necessary to drop them on the niobium oxide gated tube or immerse the niobium oxide gated tube. The supercritical carbon dioxide fluid is used to carry water and hydrogen peroxide into the interior of the niobium oxide gated tube to react.

[0052] In some embodiments, as Figure 1 shown, the niobium oxide gated tube includes:

[0053] Bottom electrode 1;

[0054] Conversion layer 2, which is located on one side of the bottom electrode 1;

[0055] Top electrode 3, which is located on the side of the conversion layer 2 away from the bottom electrode 1;

[0056] Among them, the material of the conversion layer 2 is titanium-doped niobium oxide.

[0057] In some embodiments, the material of the bottom electrode is one of Ti, Pt, W or TiN; the material of the top electrode is one of Pt or Ti.

[0058] Specifically, in this application, the material of the bottom electrode is a platinum (Pt) substrate as the bottom electrode, with a thickness of about 180 nm, in a rectangular shape, and the side length is 1 - 2 cm; a titanium-doped niobium oxide thin film is used as the conversion layer, with a thickness of about 230 nm, in the same shape as the bottom electrode; titanium (Ti) metal is used as the top electrode, with a thickness of about 86 nm; titanium (Ti) metal is used as the top electrode, in a rectangular or circular shape, and its diameter or side length is 100 - 900 μm. The top electrode 3 can be arranged in an array on the conversion layer 2.

[0059] The preparation method of the niobium oxide gated tube of this application can be obtained by using the conventional magnetron sputtering method. Specifically:

[0060] Provide the bottom electrode;

[0061] Using metallic titanium and niobium pentoxide as the targets, co-deposit titanium-doped niobium oxide on the surface of the bottom electrode by magnetron sputtering to obtain the conversion layer;

[0062] Using metallic titanium as the target, deposit titanium on the surface of the conversion layer by magnetron sputtering to obtain the top electrode;

[0063] During the preparation of the conversion layer, the sputtering power of niobium pentoxide is 40 - 60 W, and the sputtering power of titanium is 15 - 30 W.

[0064] The following further illustrates the method for supercritical fluid treatment of the niobium oxide gated tube with hydrogen peroxide as the reactant in this application with specific examples.

[0065] Example 1

[0066] The embodiment of this application provides a method for supercritical fluid treatment of the niobium oxide gated tube with hydrogen peroxide as the reactant, including the following steps:

[0067] S1. Provide a reaction chamber, clean the reaction chamber with anhydrous ethanol, and then dry it; provide a quartz bracket, immerse the quartz bracket in an ethanol solution with a mass concentration of 99.5%, perform ultrasonic oscillation, after the cleaning is completed, dry the quartz bracket; fix the niobium oxide gated tube on the quartz bracket, place the quartz bracket with the niobium oxide gated tube fixed in the reaction chamber, and add 500 μL of deionized water and 10 μL of hydrogen peroxide with a mass concentration of 30% into the reaction chamber;

[0068] S2. Introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 3000 psi and the temperature to be 120 °C, react for 1.5 h, cool down and release the pressure, and then take out the niobium oxide gated tube;

[0069] Among them, the preparation method of the niobium oxide gated tube is as follows:

[0070] Use a platinum (Pt) substrate with a thickness of about 160 nm as the bottom electrode;

[0071] Use metallic titanium and niobium pentoxide as targets, and co-deposit on the surface of the bottom electrode by magnetron sputtering to obtain titanium-doped niobium oxide, which is the conversion layer; the sputtering temperature is 300 K, and the sputtering powers of the niobium pentoxide target and the titanium dioxide target are set to 60 W and 20 W respectively, and the two targets start sputtering at the same time, and the sputtering time is set to 3000 s;

[0072] Use metallic titanium as the target, and deposit on the surface of the conversion layer by magnetron sputtering to obtain titanium with a thickness of about 86 nm as the top electrode; the sputtering temperature is 300 K, the set sputtering power is 50 W, and the sputtering time is set to 3000 s.

[0073] Example 2

[0074] The method for supercritical fluid treatment of niobium oxide gated tubes provided in the embodiment of the present application using hydrogen peroxide as a reactant is the same as that in Example 1, except that 20 μL of hydrogen peroxide with a mass concentration of 30% is added in step S1, and the remaining process conditions are the same as those in Example 1.

[0075] Example 3

[0076] The method for supercritical fluid treatment of niobium oxide gated tubes provided in the embodiment of the present application using hydrogen peroxide as a reactant is the same as that in Example 1, except that 30 μL of hydrogen peroxide with a mass concentration of 30% is added in step S1, and the remaining process conditions are the same as those in Example 1.

[0077] Example 4

[0078] The method for supercritical fluid treatment of niobium oxide gated tubes provided in the embodiment of the present application using hydrogen peroxide as a reactant is the same as that in Example 1, except that 40 μL of hydrogen peroxide with a mass concentration of 30% is added in step S1, and the remaining process conditions are the same as those in Example 1.

[0079] Example 5

[0080] The method for supercritical fluid treatment of niobium oxide gated tubes provided in the embodiment of the present application using hydrogen peroxide as a reactant is the same as that in Example 1, except that 50 μL of hydrogen peroxide with a mass concentration of 30% is added in step S1, and the remaining process conditions are the same as those in Example 1.

[0081] Comparative Example 1

[0082] This comparative example provides a method for supercritical fluid treatment of niobium oxide gated tubes, including the following steps:

[0083] S1. Provide a reaction chamber, clean the reaction chamber with anhydrous ethanol, and then dry it. Provide a quartz support, immerse the quartz support in an ethanol solution with a mass concentration of 99.5%, perform ultrasonic oscillation, and after the cleaning is completed, dry the quartz support. Fix the niobium oxide gated tube on the quartz support, place the quartz support with the niobium oxide gated tube fixed in the reaction chamber, and add 800 μL of deionized water to the reaction chamber.

[0084] S2. Introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 3000 psi and the temperature to be 120 °C, react for 1.5 h, cool down and release the pressure, and then take out the niobium oxide gated tube.

[0085] Among them, the preparation method of the niobium oxide gated tube is the same as that in Example 1.

[0086] Comparative Example 2

[0087] The method for treating the niobium oxide gated tube with supercritical fluid provided in this comparative example is the same as that in Comparative Example 1, except that 1.0 mL of deionized water is added in step S1, and the other process conditions are the same as those in Comparative Example 1.

[0088] Comparative Example 3

[0089] The method for treating the niobium oxide gated tube with supercritical fluid provided in this comparative example is the same as that in Comparative Example 1, except that 1.2 mL of deionized water is added in step S1, and the other process conditions are the same as those in Comparative Example 1.

[0090] Performance Test

[0091] Figure 2 It is the cross-sectional SEM image of the niobium oxide gated tube prepared in Example 1.

[0092] Test the resistive switching characteristics of the niobium oxide gated tube that has not been treated with supercritical fluid in Comparative Example 1. The specific test method is as follows: Use an Agilent B1500A semiconductor parameter analyzer for testing. Place the niobium oxide gated tube that has not been treated with supercritical fluid in Comparative Example 1 on the probe stage, contact the probe applying voltage with the bottom electrode (Pt), and contact the other grounded probe with the top electrode (Ti). Apply a DC sweep voltage of -2V to 2V on the top electrode, and set a current limit of 10 mA, and perform 25 cycles of sweep voltage tests. The results are as Figure 3 shown. It can be seen from Figure 3 that the niobium oxide gated tube that has not been treated with supercritical fluid does not need to undergo an additional Forming process, and the device can directly exhibit threshold switching characteristics.

[0093] Test the resistive switching characteristics of the niobium oxide gated transistor added with 800 μL of deionized water and treated by supercritical fluid. According to the same test method above, apply a DC scanning voltage of -1.5 V to 1.5 V on the top electrode, and set a current limit of 2 mA, and conduct 25 scanning voltage cycle tests. The results are as Figure 4 shown. It can be seen from Figure 4 that for the niobium oxide gated transistor added with 800 μL of deionized water and treated by supercritical fluid, it has undergone the necessary Forming process. After being treated by supercritical fluid (SCF), read the OFF-state current of the device before (corresponding to Figure 3 ) and after supercritical fluid (SCF) treatment at 0.5 V. The current of the niobium oxide gated transistor device decreased from 0.77 mA to 0.055 mA, a decrease of 14 times. This indicates that the supercritical fluid treatment technology does reduce the OFF-state current of the niobium oxide gated transistor, and can reduce the leakage current and operating power consumption in the array.

[0094] Test the resistive switching characteristics of the niobium oxide gated transistor added with 1.0 mL of deionized water and treated by supercritical fluid. According to the same test method above, apply a DC scanning voltage of -2 V to 2 V on the top electrode, and set a current limit of 3 mA, and conduct 10 scanning voltage cycle tests. The results are as Figure 5 shown.

[0095] Test the resistive switching characteristics of the niobium oxide gated transistor added with 1.2 mL of deionized water and treated by supercritical fluid. According to the same test method above, apply a DC scanning voltage of -2 V to 2 V on the top electrode, and set a current limit of 5 mA, and conduct multiple scanning voltage cycle tests. The results are as Figure 6 shown.

[0096] From Figures 5 - 6 it can be seen that after the addition amount of deionized water increases to 1.0 mL and 1.2 mL, the niobium oxide gated transistor device loses the threshold transition characteristic and shows the 1S1R characteristic. Therefore, during the supercritical fluid treatment process, the amount of deionized water added cannot be too much, otherwise the device will lose the threshold transition characteristic.

[0097] As can be seen from the above, using deionized water as a reactive substance during the supercritical fluid treatment process does reduce the OFF-state current of the niobium oxide gated transistor device, but the reduction amplitude of the OFF-state current of the device after treatment is not obvious, and the gate ratio cannot reach the ideal value (~10 2 ), and an additional large voltage needs to be applied to make the device undergo the Forming process. Therefore, during the supercritical fluid treatment process, hydrogen peroxide and deionized water are used together as reactive substances because hydrogen peroxide has better oxidizing property than deionized water and can better passivate the defects inside the material and device and at the interfaces between different materials.

[0098] The resistive switching characteristics of the niobium oxide gated tube were tested in Test Example 1 by adding 500 μL of deionized water and 10 μL of 30% hydrogen peroxide and then subjecting it to supercritical fluid treatment. According to the same testing method as above, a DC scanning voltage of -2V to 2V was applied to the top electrode, and a current limit of 3 mA was set. The results of multiple scanning voltage cycle tests are as Figure 7 shown.

[0099] The resistive switching characteristics of the niobium oxide gated tube were tested in Test Example 2 by adding 500 μL of deionized water and 20 μL of 30% hydrogen peroxide and then subjecting it to supercritical fluid treatment. According to the same testing method as above, a DC scanning voltage of -2V to 2V was applied to the top electrode, and a current limit of 5 mA was set. The results of multiple scanning voltage cycle tests are as Figure 8 shown.

[0100] The resistive switching characteristics of the niobium oxide gated tube were tested in Test Example 3 by adding 500 μL of deionized water and 30 μL of 30% hydrogen peroxide and then subjecting it to supercritical fluid treatment. According to the same testing method as above, a DC scanning voltage of -2V to 2V was applied to the top electrode, and a current limit of 3 mA was set. The results of multiple scanning voltage cycle tests are as Figure 9 shown.

[0101] The resistive switching characteristics of the niobium oxide gated tube were tested in Test Example 4 by adding 500 μL of deionized water and 40 μL of 30% hydrogen peroxide and then subjecting it to supercritical fluid treatment. According to the same testing method as above, a DC scanning voltage of -2V to 2V was applied to the top electrode, and a current limit of 5 mA was set. The results of multiple scanning voltage cycle tests are as Figure 10 shown.

[0102] The resistive switching characteristics of the niobium oxide gated tube were tested in Test Example 5 by adding 500 μL of deionized water and 50 μL of 30% hydrogen peroxide and then subjecting it to supercritical fluid treatment. According to the same testing method as above, a DC scanning voltage of -2V to 2V was applied to the top electrode, and a current limit of 30 mA was set. The results of multiple scanning voltage cycle tests are as Figure 11 shown.

[0103] It can be Figures 7 - 11 seen that when the amount of hydrogen peroxide added is 10 μL, 20 μL, and 30 μL, the reduction amplitude of the OFF-state current of the niobium oxide gated tube device is relatively small; when the amount of hydrogen peroxide increases to 40 μL, the OFF-state current of the niobium oxide gated tube device shows a relatively large reduction; while when the amount of hydrogen peroxide continues to increase to 50 μL, the OFF-state current of the niobium oxide gated tube device increases instead. The gating ratios of the gated tubes in the above five groups of experiments were calculated, and the results are as Figure 12As shown, when the content of hydrogen peroxide increased from 10 μL to 40 μL, the gating ratio reached a maximum value of 105. However, when the content of hydrogen peroxide continued to increase to 50 μL, the gating ratio decreased. It can be seen that for the niobium oxide gating tube device, at a reaction chamber temperature of 120 °C, a pressure of 3000 Psi, adding 40 μL of hydrogen peroxide with a mass concentration of 30% and 500 μL of deionized water as reactive substances and reacting for 1.5 h, the performance optimization effect of the niobium oxide gating tube device is the best, and this set of conditions is the best reaction conditions.

[0104] It should be noted that the method for calculating the gating ratio here is that the gating ratio is equal to the ratio of the current corresponding to the threshold voltage to the current corresponding to half of the threshold voltage. The gating ratio is a very important parameter of the gating tube. The larger the gating ratio, the larger the reading range in the data reading of the memory array, which also means more beneficial for the further integration and application of the device.

[0105] The resistive switching characteristics of the niobium oxide gating tube after adding 500 μL of deionized water and 40 μL of hydrogen peroxide with a mass concentration of 30% and being treated by supercritical fluid in Test Example 4, as well as the niobium oxide gating tube in Example 4 without supercritical fluid treatment, and the Forming process of the niobium oxide gating tube after being treated by supercritical fluid in Example 4 are as Figure 13 shown. Figure 13 In it, SCF treated means that the niobium oxide gating tube is treated by supercritical fluid according to the method in Example 4, WithoutSCF treated means that the niobium oxide gating tube is not treated by supercritical fluid, and The forming process means the Forming process of the niobium oxide gating tube after being treated by supercritical fluid.

[0106] From Figure 13 it can be seen that the Forming voltage of the niobium oxide gating tube device after being treated by supercritical fluid is 2 V, which is much smaller than the Forming voltage of most gating tubes and is close to the transition voltage. Such a small Forming voltage is beneficial to avoid damage to the device, so it can also be considered that this device has the Forming-free characteristic. At the same time, the ON-state current of the niobium oxide gating tube device after being treated by supercritical fluid can reach 5 mA, which is sufficient to drive most RRAMs.

[0107] Further, the niobium oxide gating tube is treated by supercritical fluid according to the method in Example 4, and at the same time, the niobium oxide gating tube without supercritical fluid treatment is used as a comparison to test the OFF-state current read at 0.4 V and the comparison of the gating ratio of the niobium oxide gating tube after different treatments. The results are as Figure 14 shown. Figure 14SCF treated means that the niobium oxide gated tube is treated with supercritical fluid according to the method in Example 4, and Without SCF treated means that the niobium oxide gated tube is not treated with supercritical fluid.

[0108] It can be seen from Figure 14 that, compared with the niobium oxide gated tube without supercritical fluid treatment, the OFF-state current of the niobium oxide gated tube device after supercritical fluid treatment has decreased by 90%, and the gating ratio of the device has increased by 700%.

[0109] Further, the niobium oxide gated tube is treated with supercritical fluid according to the method in Example 4. On the basis of Test Example 4, a scanning voltage of 0→2V→0→-2V→0 is applied to the device, and a current limit of 5 mA is set. The transition voltages (V th+ , V hold+ , V th- , V hold- ) of the treated niobium oxide gated tube device are cumulatively distributed as shown in Figure 15 . It can be seen that whether it is positive or negative, the threshold voltage and the holding voltage of the device are always equal and there is almost no fluctuation. Further, we analyze their degree of dispersion through the coefficient of variation of the four voltages. It is calculated that the coefficients of variation of (V th+ , V hold+ , V th- , V hold- ) are 2.2%, 1.6%, 1.6% and 1.8% respectively, all less than 3%. This indicates that the transition voltages of the niobium oxide gated tube device after supercritical fluid treatment are very stable, without large fluctuations, and have good consistency.

[0110] At the same time, during 100 such DC cycles, the changes in the ON-state current and OFF-state current of the device at 0.82 V and 0.41 V during 100 cycles are shown in Figure 16 . It can be seen that the OFF-state current of the device is very stable, with almost no fluctuation, and during the whole process, the gating ratio of the device is stably maintained at about two orders of magnitude. The niobium oxide gated tube device after supercritical fluid treatment not only has a lower leakage current and a larger gating ratio, but also its threshold transition performance is very stable. The niobium oxide gated tube device after supercritical fluid treatment better meets the requirements of the memory array.

[0111] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant, characterized in that, it includes the following steps: Place the niobium oxide gated tube in the reaction chamber, and add 450 - 500 μL of water and 10 - 50 μL of hydrogen peroxide with a mass concentration of 25 - 35% into the reaction chamber; Introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 2800 - 3200 psi, the temperature to be 110 - 130 °C, and the reaction time to be 1 - 2 h; The niobium oxide gated tube includes: A bottom electrode; A conversion layer, which is located on one side of the bottom electrode; A top electrode, which is located on the side of the conversion layer away from the bottom electrode; wherein, the material of the conversion layer is titanium-doped niobium oxide; The material of the bottom electrode is one of Ti, Pt, W or TiN; the material of the top electrode is one of Pt or Ti.

2. The method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant according to claim 1, characterized in that, Place the niobium oxide gated tube in the reaction chamber, and add 500 μL of water and 10 - 50 μL of hydrogen peroxide with a mass concentration of 30% into the reaction chamber.

3. The method for treating a niobium oxide gated tube by supercritical fluid using hydrogen peroxide as a reactant according to claim 2, characterized in that, Add 500 μL of water and 40 μL of hydrogen peroxide with a mass concentration of 30% into the reaction chamber; introduce supercritical carbon dioxide fluid into the reaction chamber, control the pressure in the reaction chamber to be 3000 psi, the temperature to be 120 °C, and the reaction time to be 1.5 h.

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