Memristor containing indium oxide layer and metal oxide mixed doped layer and preparation method thereof

Abstract

The application discloses a memristor containing an indium oxide layer and a metal oxide mixed doped layer and a preparation method thereof, and relates to the technical field of microelectronic device preparation. The memristor comprises, from bottom to top, a substrate, a bottom electrode, an indium oxide layer, a metal oxide mixed doped layer and a top electrode, wherein the material of the metal oxide mixed doped layer is selected from multiple kinds of aluminum oxide, hafnium oxide, zirconium oxide, zinc oxide and thallium oxide. The indium oxide layer and the metal oxide mixed doped layer are arranged in the application, and the two layers synergistically work to make the prepared memristor have excellent resistive switching performance and high stability non-volatility. The application prepares the memristor with excellent performance and stability under the premise of keeping simple process steps.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of microelectronic device preparation, and particularly relates to a memristor containing an indium oxide layer and a metal oxide mixed doped layer and a preparation method thereof. BACKGROUND

[0002] Memristors have attracted wide attention from academia and industry due to their simple structure, easy integration and resistance switching characteristics. The resistance switching characteristics can be applied to programmable logic circuits, artificial neural network simulation and resistive random access memory (RRAM). The most promising application is as RRAM. RRAM has many advantages such as high integration density, fast speed, low power consumption and non-volatility. The performance indicators of RRAM include switching ratio, set and reset voltage, durability, resistance state retention characteristics, and erase and write speed. Therefore, the performance of the memristor is excellent in the application of RRAM, and the development direction is high switching ratio, low voltage, ultra-high durability, stable resistance state retention characteristics, and ultra-fast erase and write speed.

[0003] In recent years, researchers have focused on some materials with special properties and proposed some memristor models. The most common memristor model is a "sandwich" structure, that is, a thin film material with insulating or semiconducting properties is sandwiched between two metal layers. The middle layer can be referred to as a "resistance switching layer". Different resistance switching layer materials and electrode materials will produce different resistance switching mechanisms. Among the many resistance switching layer materials, metal oxides have always been considered as potential candidates for memristor materials. The resistance switching layer material of the currently widely prepared "sandwich" structure memristor is a single layer of wide band gap metal oxide. However, although the single layer of wide band gap metal oxide layer can make these memristors temporarily exhibit a large switching ratio, the resistance state retention and durability are poor. Therefore, in view of the above shortcomings, the present application provides a memristor containing an indium oxide layer and a metal oxide mixed doped layer and a preparation method thereof. By using indium oxide and metal oxide mixed doped material to prepare a double-layer structure memristor, the excellent conductivity of indium oxide and the wide band gap insulating property of metal oxide are combined, and the performance stable resistance state retention and durability are significantly improved. SUMMARY

[0004] The present application provides a memristor containing an indium oxide layer and a metal oxide mixed doped layer and a preparation method thereof. The structure is simple, and the process is simple. By preparing a memristor containing an indium oxide layer and a metal oxide mixed doped layer, the switching ratio and cycle durability of the memristor are improved, and the device reliability and stability of the memristor applied to RRAM are improved. At the same time, the preparation method is simple, which provides a feasible preparation scheme for the commercial application of the memristor in RRAM.

[0005] To solve the above problems, the present application provides the following technical solutions:

[0006] In a first aspect, an memristor comprising an indium oxide layer and a metal oxide mixed doped layer is provided, comprising a substrate, a bottom electrode, an indium oxide layer, a metal oxide mixed doped layer and a top electrode arranged in order from bottom to top, wherein the material of the metal oxide mixed doped layer is selected from multiple kinds of aluminum oxide, hafnium oxide, zirconium oxide, zinc oxide and thallium oxide.

[0007] Further, the material of the metal oxide mixed doped layer is aluminum oxide and hafnium oxide, and the atomic percentage content ratio of the aluminum oxide to the hafnium oxide is x:(100-x), wherein 1≤x≤50.

[0008] Preferably, the atomic percentage content ratio of the aluminum oxide to the hafnium oxide is 3.5:96.5.

[0009] Further, the material of the metal oxide mixed doped layer is zinc oxide and hafnium oxide, and the atomic percentage content ratio of the zinc oxide to the hafnium oxide is x:(100-x), wherein 1≤x≤50.

[0010] Further, the material of the substrate is selected from one of silicon, silicon dioxide, silicon carbide, glass, polyimide and polydimethylsiloxane, the material of the bottom electrode is indium tin oxide, and the material of the top electrode is one or more of aluminum, gold, silver, copper, titanium, nickel, titanium nitride, indium tin oxide and graphene.

[0011] Further, the thickness of the indium oxide layer is 2-100 nm, and the thickness of the metal oxide mixed doped layer is 2-100 nm.

[0012] Further, the thickness of the bottom electrode is 20-1000 nm, and the thickness of the top electrode is 10-1000 nm.

[0013] In a second aspect, a preparation method of the memristor comprising the indium oxide layer and the metal oxide mixed doped layer is provided, comprising the following steps:

[0014] (1) cleaning and drying the substrate;

[0015] (2) depositing the bottom electrode on the substrate by using a physical vapor deposition method;

[0016] (3) after depositing the bottom electrode, performing mask on the bottom electrode, and depositing the indium oxide layer by using a magnetron sputtering method;

[0017] (4) after depositing the indium oxide layer, depositing the metal oxide mixed doped layer by using a magnetron sputtering method;

[0018] (5) removing the mask in step (3), covering and fixing the patterned mask plate on the mixed metal oxide doped layer, and depositing the top electrode by physical vapor deposition to prepare the device;

[0019] (6) annealing the device prepared in step (5) in a heating stage, and then taking out the device to obtain the memristor containing the indium oxide layer and the mixed metal oxide doped layer.

[0020] Preferably, in step (2), the bottom electrode is deposited by physical vapor deposition by using a magnetron sputtering method, keeping the sputtering chamber at a pressure of 0.1-1.5 Pa, and sputtering the bottom electrode target under the condition of keeping the argon atmosphere at 30-60 sccm and adjusting the sputtering power to 35-60 W.

[0021] Further, in step (3), the indium oxide resistive switching layer is deposited by using a magnetron sputtering method by keeping the sputtering chamber at a pressure of 0.1-1.5 Pa after vacuumizing, sputtering the indium oxide target under the condition of an argon and oxygen atmosphere at a ratio of (10-5):1, adjusting the sputtering power to 35-60 W, and sputtering under the condition of keeping the heating temperature of the base table carrying the substrate at 40-200℃ and the rotation speed at 5-20 r / min, and the sputtering time is 2-10 min.

[0022] Further, in step (4), the mixed metal oxide doped layer is deposited by using a magnetron sputtering method by keeping the sputtering chamber at a pressure of 0.1-1.5 Pa after vacuumizing, sputtering the metal oxide target under the condition of keeping no oxygen or keeping the argon atmosphere at 45-60 sccm, adjusting the sputtering power to 35-60 W, and sputtering under the condition of keeping the heating temperature of the base table carrying the substrate at 40-200℃ and the rotation speed at 5-20 r / min, and the sputtering time is 2-15 min.

[0023] Preferably, in step (5), the top electrode is deposited by physical vapor deposition by using a magnetron sputtering method, keeping the sputtering chamber at a pressure of 0.1-1.5 Pa, sputtering the top electrode target under the condition of keeping the argon atmosphere at 30-60 sccm, and sputtering under the condition of keeping the heating temperature of the base table carrying the substrate at 40-100℃ and the rotation speed at 5-20 r / min, and the sputtering time is 2-20 min.

[0024] Preferably, in step (5), the top electrode is deposited by physical vapor deposition by using a vacuum thermal evaporation method, evaporating the aluminum particles by gradually increasing the evaporation current, and keeping the temperature of the substrate carrying the aluminum particles at 80-120℃.

[0025] Further, in step (6), the annealing temperature is 100-500 DEG C, and the annealing time is 1-500 min.

[0026] Compared with the prior art, the application has the beneficial effects that:

[0027] 1. Indium oxide is used as one of the resistive switching layer materials; wherein, as a highly potential new type of semiconductor material, indium oxide has high transparency and excellent electrical conductivity, and has electron transmission performance similar to that of graphene, and is a very good conductive material. Indium oxide has very good mechanical properties, high hardness, good toughness, and good wear resistance and corrosion resistance, and thus can be used to prepare high-quality thin film materials. As an emerging thin film material, indium oxide has unique performance and characteristics in semiconductor devices, especially excellent performance in transparency, electrical conductivity and mechanical properties, and provides a broad prospect for its application in microelectronic devices. In addition, indium oxide, like aluminum oxide and hafnium oxide, has high temperature stability and can work stably at high temperature. And hafnium oxide and aluminum oxide are materials with large dielectric constant, and are often used in the manufacture of capacitors and other devices.

[0028] 2. The method for depositing an indium oxide layer by magnetron sputtering is used, different thicknesses of the indium oxide layer are prepared by changing the sputtering power, sputtering time and other preparation processes, and different degrees of oxidation of the indium oxide layer are obtained by different oxygen flow rates during sputtering and different annealing temperatures, so that the memory resistor with the mixed doped layer containing the indium oxide layer and the metal oxide layer with different performances is prepared.

[0029] 3. The top electrode of the memory resistor of the application can be other metal or non-metal materials.

[0030] 4. The memory resistor with the mixed doped layer containing the indium oxide layer and the metal oxide layer provided by the application has excellent resistive switching performance and high stability non-volatility by setting the indium oxide layer and the mixed doped layer containing the metal oxide, and the synergistic effect of the two makes the prepared memory resistor have excellent performance and stability. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0032] Figure 1 The structure schematic diagram of the memory resistor with the mixed doped layer containing the indium oxide layer and the metal oxide of the application embodiment 1 is shown in the figure.

[0033] Figure 2 Flow chart for the preparation method of the memristor with the indium oxide layer and the metal oxide mixed doped layer according to the embodiment 1 of the present application;

[0034] Figure 3 I-V curve diagram of the memristor with the indium oxide layer and the metal oxide mixed doped layer according to the embodiment 1 of the present application, which was tested by 5 cycles of scanning period;

[0035] Figure 4 I-V curve diagram of the memristor with the indium oxide layer and the metal oxide mixed doped layer according to the embodiment 4 of the present application, which was tested by 5 cycles of scanning period;

[0036] Figure 5 I-V curve diagram of the memristor with the metal oxide mixed doped layer according to the comparative example 1 of the present application, which was tested by 5 cycles of scanning period;

[0037] Figure 6 I-V curve diagram of the memristor with the indium oxide layer according to the comparative example 2 of the present application, which was tested by 5 cycles of scanning period.

[0038] Figure 7 I-V curve diagram of the memristor with the indium oxide layer and the metal oxide mixed doped layer according to the comparative example 3 of the present application, which was tested by 5 cycles of scanning period.

[0039] Explanation of the figure:

[0040] 1-substrate; 2-bottom electrode; 3-indium oxide layer; 4-metal oxide mixed doped layer; 5-top electrode. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the embodiments described below are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without any creative work, fall within the protection scope of the present application.

[0042] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all the technical and scientific terms used in the present application have the same meaning as generally understood by a person of ordinary skill in the art to which the present application belongs.

[0043] In the present application, the terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only a relationship word determined for the convenience of describing the structural relationship of the components or elements of the present application, and cannot be understood as a limitation on the present application.

[0044] Embodiment 1

[0045] As shown in Figure 1 , the present application provides a memristor containing an indium oxide layer and a metal oxide mixed doped layer, which comprises, from bottom to top, a substrate 1, a bottom electrode 2, an indium oxide layer 3, a metal oxide mixed doped layer 4 and a top electrode 5. The material of the metal oxide mixed doped layer 4 is aluminum oxide and hafnium oxide, and the atomic percentage content ratio of aluminum oxide to hafnium oxide is 3.5:96.5. The material of the substrate 1 is silicon dioxide, the material of the bottom electrode 2 is indium tin oxide, and the material of the top electrode 5 is copper.

[0046] As shown in Figure 2 , the present application provides a preparation method of a memristor containing an indium oxide layer and a metal oxide mixed doped layer, which comprises the following steps:

[0047] (1) cleaning and drying the substrate;

[0048] (2) depositing the bottom electrode on the substrate using the physical vapor deposition method: using the magnetron sputtering method, keeping the sputtering instrument at an air pressure of 1 Pa, sputtering the bottom electrode target material under the condition of keeping an atmosphere of 40 sccm of argon gas, adjusting the sputtering power to 45 W;

[0049] (3) after depositing the bottom electrode, masking the bottom electrode (sticking masking tape on the bottom electrode), depositing the indium oxide layer using the magnetron sputtering method: after evacuating the sputtering instrument chamber to keep the air pressure at 1 Pa, sputtering the indium oxide target material under the condition of an atmosphere with a ratio of argon gas to oxygen gas of 8:1 (40 sccm of argon gas and 5 sccm of oxygen gas), adjusting the sputtering power to 45 W, and sputtering under the condition of keeping the base station carrying the substrate at a heating temperature of 60℃ and a rotation speed of 15r / min, the sputtering time is 4min;

[0050] (4) after depositing the indium oxide layer, depositing the metal oxide mixed doped layer using the magnetron sputtering method: after evacuating the sputtering instrument chamber to keep the air pressure at 1 Pa, sputtering the metal oxide mixed doped target material under the condition of keeping an atmosphere without oxygen gas, adjusting the sputtering power to 45 W, and sputtering under the condition of keeping the base station carrying the substrate at a heating temperature of 60℃ and a rotation speed of 15r / min, the sputtering time is 3min;

[0051] (5) Remove the mask in step (3) (remove the mask tape), cover and fix the patterned mask plate on the metal oxide mixed doped layer, and deposit the top electrode using the physical vapor deposition method: using the magnetron sputtering method, the sputtering chamber is kept at a pressure of 1 Pa, the argon gas is kept at a flow rate of 45 sccm, and the substrate is kept at a heating temperature of 80°C and a rotation speed of 10 r / min. The sputtering time is 8 min; the device is prepared;

[0052] (6) Put the device prepared in step (5) into the heating stage, anneal at a temperature of 400°C for 10 min, and then take it out, thereby obtaining the indium oxide layer and the metal oxide mixed doped layer of the memristor of Example 1.

[0053] The prepared indium oxide layer and metal oxide mixed doped layer of the memristor of Example 1 are tested by I-V scanning test using a semiconductor analyzer B1500A, and after the test, the sample is prepared using a focused ion beam (FIB), and then the thickness of each layer is observed using a transmission electron microscope (TEM). The thickness of the indium oxide layer is 20 nm, the thickness of the metal oxide mixed doped layer is 10 nm, the thickness of the bottom electrode is 200 nm, and the thickness of the top electrode is 30 nm.

[0054] The I-V curve of the memristor prepared in Example 1 is tested by 5 cycles of scanning period using a semiconductor analyzer B1500A, as shown in Figure 3 The abscissa represents the scanning voltage, and the ordinate represents the current value flowing through the device. From Figure 3 , it can be observed that the thick curve presents a high resistance state when scanning from 0V to 3V, and the current flowing through the device is relatively small. When the voltage increases to about 3V, the current increases sharply, which indicates that the device changes the resistance state at this moment, showing a low resistance value, so the current suddenly increases. This process is called setting process, and the voltage at this time is called set voltage. Then the current remains in a low resistance state from 3V to 0V. Subsequently, the voltage is scanned from 0V to -3V, and the device shows a non-volatile characteristic, still maintaining a large current and a low resistance state. When the voltage is scanned from -3V to 0V, the current can be seen to decrease sharply between -1V and -0.5V, and the device switches to a high resistance state at this moment, and the current flowing through the device remains small. The voltage is scanned in this cycle repeatedly for 5 periods. Although the position of the set voltage changes slightly in the subsequent cycles, it remains within the range of 1.5V to 3V. From Figure 3The current of the high and low resistance states can be observed to be very stable and have very good repeatability, and each voltage scanning cycle can better coincide with the track of the last cycle. And under the 0.2V reading voltage, the ratio (on-off ratio) of the high and low resistance states of the device reaches 15-30.

[0055] Example 2

[0056] The memristor containing an indium oxide layer and a metal oxide mixed doped layer comprises, from bottom to top, a substrate, a bottom electrode, an indium oxide layer, a metal oxide mixed doped layer and a top electrode. The material of the metal oxide mixed doped layer is aluminum oxide and hafnium oxide, and the atomic percentage content ratio of aluminum oxide to hafnium oxide is 50:50. The material of the substrate is silicon dioxide, the material of the bottom electrode is indium tin oxide, and the material of the top electrode is copper.

[0057] The preparation method of the memristor containing an indium oxide layer and a metal oxide mixed doped layer of Example 2 comprises the following steps:

[0058] (1) clean and dry the substrate;

[0059] (2) deposit the bottom electrode on the substrate using the physical vapor deposition method: use the magnetron sputtering method, keep the sputtering instrument at an air pressure of 1Pa, sputter the bottom electrode target material under the condition of keeping an atmosphere of 40sccm of argon gas, and adjust the sputtering power to 45W;

[0060] (3) after depositing the bottom electrode, mask the bottom electrode (paste the mask tape on the bottom electrode), and deposit the indium oxide layer using the magnetron sputtering method: after vacuumizing the sputtering instrument, keep it at an air pressure of 1Pa, sputter the indium oxide target material under the condition of an atmosphere of argon and oxygen in a ratio of 8:1 (argon 40sccm and oxygen 5sccm), adjust the sputtering power to 45W, and sputter under the condition of keeping the base station carrying the substrate at a heating temperature of 60℃ and a rotation speed of 15r / min, and the sputtering time is 4min; (4) after depositing the indium oxide layer, deposit the metal oxide mixed doped layer using the magnetron sputtering method: after vacuumizing the sputtering instrument, keep it at an air pressure of 1Pa, sputter the metal oxide mixed doped target material under the condition of keeping an atmosphere without oxygen, adjust the sputtering power to 45W, and sputter under the condition of keeping the base station carrying the substrate at a heating temperature of 60℃ and a rotation speed of 15r / min, and the sputtering time is 3min;

[0061] (5) Remove the mask in step (3) (remove the mask tape), cover and fix the patterned mask plate on the metal oxide mixed doped layer, and deposit the top electrode using the physical vapor deposition method: using the magnetron sputtering method, the sputtering instrument is maintained at a gas pressure of 1 Pa, the top electrode target material is sputtered under the condition of maintaining an atmosphere of 45 sccm of argon gas, and the sputtering is carried out under the condition of maintaining a heating temperature of 80°C and a rotation speed of 10 r / min for the base station of the mounted substrate, and the sputtering time is 8 min; the device is prepared;

[0062] (6) Put the device prepared in step (5) into a heating station, and take it out after annealing at an annealing temperature of 400°C for 10 min, thereby obtaining the indium oxide layer and the metal oxide mixed doped layer of the memristor of example 2.

[0063] The prepared indium oxide layer and metal oxide mixed doped layer of the memristor of example 2 are tested by I-V scanning test using a semiconductor analyzer B1500A, and after the test, the sample is prepared using a focused ion beam (FIB), and then the thickness of each layer is observed using a transmission electron microscope (TEM), and the thickness of the indium oxide layer is 20 nm, the thickness of the metal oxide mixed doped layer is 10 nm, the thickness of the bottom electrode is 200 nm, and the thickness of the top electrode is 30 nm.

[0064] The atomic percentage content of aluminum oxide and hafnium oxide in the metal oxide mixed doped layer of the memristor of example 2 is 50:50. After 5 I-V scanning cycle tests of the memristor prepared in example 2 using a semiconductor analyzer B1500A, the results show that the switching ratio of example 2 is slightly smaller than that of example 1, but the performance in switching durability and repeatability of the resistance state is comparable to that of example 1.

[0065] After mathematical calculation,

[0066] Because the mass ratio of aluminum oxide and hafnium oxide is 50:50, i.e. (Al2O3:HfO2=50:50);

[0067] Assuming that the total mass of the deposited metal oxide is N mol;

[0068] Then the content of aluminum oxide is 0.5N mol, and the content of hafnium oxide is also 0.5N mol;

[0069] Then the total atomic content is: 0.5N mol×5+0.5N mol×3=4N mol;

[0070] Then the content of oxygen atoms is: 0.5N mol×3+0.5N mol×2=2.5N mol;

[0071] The percentage of oxygen atoms in the total atomic content is (2.5N mol / 4N mol) x 100% = 62.5%

[0072] The oxygen atom content of the metal oxide mixed doped layer in Example 2 is smaller than that of the target material in Example 1, and the oxygen atom plays an important role in the conduction process of the memristor. Thus, it is explored by experiments and test results that when the atomic percentage content of aluminum oxide and hafnium oxide is 50:50, the comprehensive performance of the memristor is still considerable.

[0073] Example 3

[0074] A memristor containing an indium oxide layer and a metal oxide mixed doped layer, comprising a substrate, a bottom electrode, an indium oxide layer, a metal oxide mixed doped layer and a top electrode arranged in order from bottom to top. The material of the metal oxide mixed doped layer is aluminum oxide and hafnium oxide, and the atomic percentage content ratio of aluminum oxide and hafnium oxide is 1:99. The material of the substrate is silicon dioxide, the material of the bottom electrode is indium tin oxide, and the material of the top electrode is copper.

[0075] The preparation method of the memristor containing an indium oxide layer and a metal oxide mixed doped layer in Example 3, comprising the following steps:

[0076] (1) cleaning and drying the substrate;

[0077] (2) depositing the bottom electrode on the substrate using the physical vapor deposition method: using the magnetron sputtering method, keeping the sputtering instrument at 1 Pa of air pressure, sputtering the bottom electrode target material under the condition of keeping 40 sccm of argon gas atmosphere, adjusting the sputtering power to 45 W;

[0078] (3) after depositing the bottom electrode, masking the bottom electrode (sticking masking tape on the bottom electrode), depositing the indium oxide layer using the magnetron sputtering method: after vacuumizing the sputtering instrument, keeping it at 1 Pa of air pressure, sputtering the indium oxide target material under the condition of argon and oxygen ratio of 8:1 (argon 40 sccm and oxygen 5 sccm) atmosphere, adjusting the sputtering power to 45 W, and keeping the base station carrying the substrate at a heating temperature of 60℃ and a rotation speed of 15r / min to sputter, the sputtering time is 4min; (4) after depositing the indium oxide layer, depositing the metal oxide mixed doped layer using the magnetron sputtering method: after vacuumizing the sputtering instrument, keeping it at 1 Pa of air pressure, sputtering the metal oxide mixed doped target material under the condition of keeping no oxygen gas, adjusting the sputtering power to 45 W, and keeping the base station carrying the substrate at a heating temperature of 60℃ and a rotation speed of 15r / min to sputter, the sputtering time is 3min;

[0079] (5) Remove the mask in step (3) (remove the mask tape), cover and fix the patterned mask plate on the metal oxide mixed doped layer, and deposit the top electrode using the physical vapor deposition method: using the magnetron sputtering method, the sputtering instrument is maintained at a gas pressure of 1 Pa, the top electrode target material is sputtered under the condition of maintaining an atmosphere of 45 sccm of argon gas, and the base of the mounted substrate is maintained at a heating temperature of 80°C and a rotation speed of 10 r / min. The sputtering time is 8 min; the device is prepared;

[0080] (6) Put the device prepared in step (5) into a heating stage, and anneal at an annealing temperature of 400°C for 10 min, then take out, to obtain the indium oxide layer and the metal oxide mixed doped layer of the memristor of example 3.

[0081] The prepared indium oxide layer and metal oxide mixed doped layer of the memristor of example 3 are tested by I-V scanning test using a semiconductor analyzer B1500A, and after the test, the sample is prepared using a focused ion beam (FIB), and then the thickness of each layer is observed using a transmission electron microscope (TEM). The thickness of the indium oxide layer is 20 nm, the thickness of the metal oxide mixed doped layer is 10 nm, the thickness of the bottom electrode is 200 nm, and the thickness of the top electrode is 30 nm.

[0082] The atomic percentage content of aluminum oxide and hafnium oxide in the metal oxide mixed doped layer of the memristor of example 3 is 1:99. The I-V scanning test results of the indium oxide layer and the metal oxide mixed doped layer of the memristor prepared in example 3 using a semiconductor analyzer B1500A show that the switching ratio of the memristor in example 3 is larger than that of the memristor in example 1, and the performance is slightly better, but the switching durability and the repeatability of the resistance state are slightly worse than those of the memristor in example 1. As in the calculation in example 2, the atomic percentage content of oxygen in example 3 is calculated to be 66.56%, and the increase of the oxygen atomic content slightly increases the switching ratio of the memristor, but the stability is worse. Therefore, according to the experimental results of example 3, when the atomic percentage content of aluminum oxide and hafnium oxide is 1:99, the switching ratio performance of the memristor is better, but the stability is slightly worse. Overall, the balanced performance of the two performances is relatively moderate.

[0083] Example 4

[0084] The memory resistor with an indium oxide layer and a metal oxide mixed doped layer comprises, from bottom to top, a substrate, a bottom electrode, an indium oxide layer, a metal oxide mixed doped layer and a top electrode, wherein the material of the metal oxide mixed doped layer is hafnium oxide and zinc oxide, the atomic percentage ratio of the hafnium oxide and the zinc oxide is 50:50, the material of the substrate is silicon dioxide, the material of the bottom electrode is indium tin oxide, and the material of the top electrode is aluminum.

[0085] The preparation method of the memory resistor with an indium oxide layer and a metal oxide mixed doped layer comprises the following steps:

[0086] (1) cleaning and drying the substrate;

[0087] (2) depositing the bottom electrode on the substrate by using a physical vapor deposition method: using a magnetron sputtering method, keeping the sputtering instrument at an air pressure of 1 Pa, sputtering a bottom electrode target under the condition of keeping an atmosphere of 40 sccm of argon gas, and adjusting the sputtering power to 45 W;

[0088] (3) after depositing the bottom electrode, performing mask on the bottom electrode (pasting a mask tape on the bottom electrode), and depositing the indium oxide layer by using a magnetron sputtering method: after vacuumizing the sputtering instrument, keeping the sputtering instrument at an air pressure of 1 Pa, sputtering an indium oxide target under the condition of an atmosphere of argon and oxygen in a ratio of 8:1 (40 sccm of argon and 5 sccm of oxygen), adjusting the sputtering power to 45 W, and sputtering under the condition of keeping the heating temperature of the base station carrying the substrate at 80℃ and the rotation speed at 10 r / min, and the sputtering time is 3.5 min;

[0089] (4) after depositing the indium oxide layer, depositing the metal oxide mixed doped layer by using a magnetron sputtering method: after vacuumizing the sputtering instrument, keeping the sputtering instrument at an air pressure of 1 Pa, sputtering a metal oxide target under the condition of keeping an atmosphere of 45 sccm of argon gas, adjusting the sputtering power to 40 W, and sputtering under the condition of keeping the heating temperature of the base station carrying the substrate at 80℃ and the rotation speed at 10 r / min, and the sputtering time is 3 min;

[0090] (5) removing the mask in step (3) (removing the mask tape), covering and fixing a patterned mask plate on the metal oxide mixed doped layer, and depositing the top electrode by using a physical vapor deposition method: using a vacuum thermal evaporation method, evaporating the top electrode in the thermal evaporation instrument, taking 2 g of aluminum particles, gradually increasing the evaporation current, evaporating the aluminum particles, keeping the temperature of the carrier base station above the aluminum particles at 100℃, and obtaining the device;

[0091] The prepared memory resistor of Example 4 was tested by I-V scan using semiconductor analyzer B1500A. After the test, the memory resistor was sampled using focused ion beam (FIB), and then the thicknesses of the layers were observed using transmission electron microscope (TEM). The thickness of the indium oxide layer was 20 nm, the thickness of the metal oxide mixed doped layer was 10 nm, the thickness of the bottom electrode was 200 nm, and the thickness of the top electrode was 30 nm.

[0092] The I-V curve of the memory resistor of Example 4 with the indium oxide layer and the metal oxide mixed doped layer tested by 5-cycle scan using semiconductor analyzer B1500A is shown in FIG. 2. The abscissa represents the scan voltage, and the ordinate represents the current value flowing through the device. Figure 4 Figure 4 As can be seen from FIG. 2, when scanning from 0 V to 3 V, the device shows a high resistance state when the voltage is less than 1 V. When the voltage increases to between 1 V and 2 V, the current suddenly increases, the memory resistor switches to a low resistance state, and the memory resistor completes the set process. Then the current remains in the low resistance state from 3 V to 0 V. Subsequently, the voltage is scanned from 0 V to -3 V, and the device shows a non-volatile characteristic, still in a low resistance state. When the voltage is scanned from -3 V to 0 V, it can be seen that the current decreases, and the memory resistor switches to a high resistance state. This cycle is repeated 5 times. As can be observed from FIG. 2, the on-off ratio of the device reaches 5-10 at a read voltage of 0.2 V, and the current flowing through the device is relatively stable, and the repeatability is also good. Figure 4

[0093] Comparative Example 1

[0094] A memory resistor with a metal oxide mixed doped layer includes, from bottom to top, a substrate, a bottom electrode, a metal oxide mixed doped layer, and a top electrode. The material of the metal oxide mixed doped layer is aluminum oxide and hafnium oxide, and the atomic percentage content ratio of aluminum oxide to hafnium oxide is 3.5:96.5. The material of the substrate is silicon dioxide, the material of the bottom electrode is indium tin oxide, and the material of the top electrode is copper.

[0095] A method for preparing a memory resistor with a metal oxide mixed doped layer includes the following steps:

[0096] (1) cleaning and drying the substrate;

[0097] (2) depositing the bottom electrode on the substrate using physical vapor deposition: using a magnetron sputtering method, the sputtering instrument is maintained at a pressure of 1 Pa, the bottom electrode target material is sputtered under the condition of maintaining an atmosphere of 40 sccm of argon gas, and the sputtering power is adjusted to 45 W;

[0098] ​​(3) After the deposition of the bottom electrode, the bottom electrode was masked (a mask tape was pasted on the bottom electrode), and a metal oxide mixed doped layer was deposited by using a magnetron sputtering method: the sputtering instrument was vacuumized and kept at an air pressure of 1 Pa, a metal oxide mixed doped target was sputtered under the condition of keeping an oxygen-free atmosphere, the sputtering power was adjusted to 45 W, and the sputtering was performed under the condition of keeping the heating temperature of the base table of the substrate at 60 °C and the rotation speed at 15 r / min, and the sputtering time was 3 min;

[0099] (4) The mask in step (3) was removed (the mask tape was removed), a patterned mask plate was overlaid and fixed on the metal oxide mixed doped layer, and a top electrode was deposited by using a physical vapor deposition method: the top electrode target was sputtered by using a magnetron sputtering method, the sputtering instrument was kept at an air pressure of 1 Pa, and the sputtering was performed under the condition of keeping the atmosphere of 45 sccm of argon gas and keeping the heating temperature of the base table of the substrate at 80 °C and the rotation speed at 10 r / min, and the sputtering time was 8 min; and the device was prepared;

[0100] (5) The device prepared in step (4) was placed in a heating table, annealed at an annealing temperature of 400 °C for 10 min, and then taken out, thereby obtaining the metal oxide mixed doped layer-containing memristor of Comparative Example 1.

[0101] The prepared metal oxide mixed doped layer-containing memristor of Comparative Example 1 was subjected to I-V scan testing by using a semiconductor analyzer B1500A. After the testing, the memristor was sampled by using a focused ion beam (FIB), and then the thicknesses of the layers were observed by using a transmission electron microscope (TEM), and it was found that the thickness of the metal oxide mixed doped layer was 30 nm, the thickness of the bottom electrode was 200 nm, and the thickness of the top electrode was 30 nm.

[0102] The I-V curve obtained by using the semiconductor analyzer B1500A to test the metal oxide mixed doped layer-containing memristor prepared in Comparative Example 1 for 5 cycles of scanning is shown in FIG. 1. Figure 5 In the first cycle of scanning, when the voltage was scanned from 0 V to 3 V, the device was switched to a low resistance state at about 2.7 V, and a large current was maintained to return to 0 V. Figure 5 It can be directly seen from FIG. 1 that the on-off ratio of the device is very large, and reaches the order of 10 5 at a read voltage of 0.2 V. However, in the subsequent 4 cycles of scanning, the super-high on-off ratio performance disappeared, and the ratio of the high resistance state to the low resistance state was very small, which indicated that the reliability and stability of the device as a resistive random access memory (RRAM) for storing information were poor. At the same time, this also indicated that the indium oxide layer played a certain role in improving the performance of the memristor.

[0103] Comparative Example 2

[0104] The memory resistor with indium oxide layer comprises, from bottom to top, a substrate, a bottom electrode, an indium oxide layer and a top electrode. The substrate is made of silicon dioxide, the bottom electrode is made of indium tin oxide, and the top electrode is made of copper.

[0105] The preparation method of the memory resistor with indium oxide layer comprises the following steps:

[0106] (1) cleaning and drying the substrate;

[0107] (2) depositing the bottom electrode on the substrate by physical vapor deposition: using a magnetron sputtering method, keeping the sputtering instrument at an air pressure of 1 Pa, sputtering the bottom electrode target under the condition of keeping an atmosphere of 40 sccm of argon gas, and adjusting the sputtering power to 45 W;

[0108] (3) after depositing the bottom electrode, masking the bottom electrode (pasting a masking tape on the bottom electrode), and depositing the indium oxide layer by using a magnetron sputtering method: after vacuumizing the sputtering instrument, keeping the air pressure at 1 Pa, sputtering the indium oxide target under the condition of an atmosphere of argon and oxygen in a ratio of 8:1 (40 sccm of argon and 5 sccm of oxygen), adjusting the sputtering power to 45 W, and sputtering under the condition of keeping the base station carrying the substrate at a heating temperature of 60 DEG C and a rotation speed of 15 r / min, and the sputtering time is 4 min;

[0109] (4) removing the mask in step (3) (removing the masking tape), covering and fixing the patterned mask plate on the indium oxide layer, and depositing the top electrode by physical vapor deposition: using a magnetron sputtering method, keeping the sputtering instrument at an air pressure of 1 Pa, sputtering the top electrode target under the condition of keeping an atmosphere of 45 sccm of argon gas, and sputtering under the condition of keeping the base station carrying the substrate at a heating temperature of 80 DEG C and a rotation speed of 10 r / min, and the sputtering time is 8 min; and obtaining the device;

[0110] (5) placing the device prepared in step (4) into a heating station, annealing under the condition of an annealing temperature of 400 DEG C and an annealing time of 10 min, and then taking out, to obtain the memory resistor with indium oxide layer of Comparative Example 2.

[0111] The memory resistor with indium oxide layer prepared in Comparative Example 2 is subjected to I-V scanning test by using B1500A, and after the test, the sample of the memory resistor is prepared by using focused ion beam (FIB), and then the thicknesses of the layers are observed by using transmission electron microscope (TEM), to obtain that the thickness of the indium oxide layer is 25 nm, the thickness of the bottom electrode is 200 nm, and the thickness of the top electrode is 30 nm.

[0112] The I-V curve diagram of the memory resistor with indium oxide layer prepared in Comparative Example 2 subjected to 5-cycle scanning test by using semiconductor analyzer B1500A is as follows:Figure 6 The horizontal axis represents the scanning voltage, and the vertical axis represents the current value flowing through the device. As can be seen from the figure, the current is almost the same during the voltage scanning from 0 V to 3 V and from 3 V to 0 V in the 5 scanning cycles. Figure 6 It can be seen that the current is almost the same during the voltage scanning from 0 V to 3 V and from 3 V to 0 V in the 5 scanning cycles. This indicates that the resistance state of the device does not change obviously, and there is no high resistance state and low resistance state, and the on-off ratio tends to 1 (i.e. no switching behavior). The device performance is poor. This indicates that the metal oxide mixed doped layer plays an important role in the switching performance of the memristor.

[0113] Comparative Example 3

[0114] Comparative Example 3 is different from Example 1 in that the atomic percentage ratio of aluminum oxide to hafnium oxide is 60:40, and the rest of the conditions are the same.

[0115] The prepared memristor of Comparative Example 3 containing an indium oxide layer and a metal oxide mixed doped layer was subjected to I-V scanning test using a semiconductor analyzer B1500A, and after the test, the sample was prepared using a focused ion beam (FIB), and then the thicknesses of the layers were observed using a transmission electron microscope (TEM), and the thickness of the indium oxide layer was 20 nm, the thickness of the metal oxide mixed doped layer was 10 nm, the thickness of the bottom electrode was 200 nm, and the thickness of the top electrode was 30 nm.

[0116] The I-V curve of the memristor of Comparative Example 3 containing an indium oxide layer and a metal oxide mixed doped layer was subjected to 5-cycle scanning using a semiconductor analyzer B1500A, and the result is shown in Figure 7 The horizontal axis represents the scanning voltage, and the vertical axis represents the current value flowing through the device. As can be seen from the figure, the current is almost the same during the voltage scanning from 0 V to 3 V and from 3 V to 0 V in the 5 scanning cycles. Figure 7 It can be seen that the switching ratio performance of the device is slightly worse than that of Example 1, which is related to the increase of the doping concentration of aluminum oxide and the decrease of the oxygen atom content. Therefore, it can be concluded that this doping ratio is not the best doping ratio of aluminum oxide and hafnium oxide.

[0117] In summary, the memristor containing an indium oxide layer and a metal oxide mixed doped layer and the preparation method thereof provided by the present application can exhibit stable high-low dual resistance state switching and non-volatile storage behavior through the synergistic effect of the indium oxide layer and the metal oxide mixed doped layer. The presence of the indium oxide layer has a significant improvement and help on the performance index of the non-volatile storage of the memristor. In addition, the present application provides a simple structure and simple process scheme for the application and development of the memristor in non-volatile memory.

[0118] In the above examples, the description of each example has its own focus, and the parts not described in detail in a certain example can be referred to the related description of other examples.

[0119] The above is a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for manufacturing a memristor comprising an indium oxide layer and a mixed-doped metal oxide layer, characterized in that, It comprises the following steps: (1) cleaning and drying the substrate; (2) depositing the bottom electrode on the substrate by using the method of physical vapor deposition; (3) after depositing the bottom electrode, masking the bottom electrode, and depositing the indium oxide layer by using the method of magnetron sputtering; (4) after depositing the indium oxide layer, depositing the metal oxide mixed doped layer by using the method of magnetron sputtering; (5) removing the mask in step (3), covering and fixing the patterned mask plate on the metal oxide mixed doped layer, depositing the top electrode by using the method of physical vapor deposition, and preparing the device; (6) placing the device prepared in step (5) into a heating table for annealing, and then taking it out, thereby obtaining the memristor containing the indium oxide layer and the metal oxide mixed doped layer; In step (3), the method of depositing the indium oxide layer by using magnetron sputtering is as follows: after the sputtering instrument is vacuumed, it is kept at a pressure of 0.1-1.5 Pa, the indium oxide target is sputtered in an atmosphere with a ratio of argon to oxygen being (10-5):1, the sputtering power is adjusted to 35-60 W, the base table carrying the substrate is kept at a heating temperature of 40-200℃ and a rotating speed of 5-20 r / min, and the sputtering time is 2-10 min; In step (4), the method of depositing the metal oxide mixed doped layer by using magnetron sputtering is as follows: after the sputtering instrument is vacuumed, it is kept at a pressure of 0.1-1.5 Pa, the metal oxide target is sputtered in an atmosphere with no oxygen or 40-60 sccm argon, the sputtering power is adjusted to 35-60 W, the base table carrying the substrate is kept at a heating temperature of 40-200℃ and a rotating speed of 5-20 r / min, and the sputtering time is 2-15 min; The memristor containing the indium oxide layer and the metal oxide mixed doped layer comprises, from bottom to top, a substrate, a bottom electrode, an indium oxide layer, a metal oxide mixed doped layer, and a top electrode; The material of the metal oxide mixed doped layer is aluminum oxide and hafnium oxide, the atomic percentage content ratio of the aluminum oxide to the hafnium oxide is x:(100-x), 1≤x≤50, or the material of the metal oxide mixed doped layer is aluminum oxide and hafnium oxide, the atomic percentage content ratio of the aluminum oxide to the hafnium oxide is x:(100-x), 1≤x≤50.

2. The method of claim 1, wherein the method further comprises: depositing a metal oxide layer on the metal oxide layer; and depositing a metal layer on the metal oxide layer. In step (6), the annealing temperature is 100-500℃, and the annealing time is 1-500 min.

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