A gate tube based on lithium nickel oxide material and its manufacturing method

Abstract

The present invention provides a gate tube based on lithium nickel oxide material and its manufacturing method. The gate tube includes a bottom electrode; an intermediate layer material located on the surface of one side of the bottom electrode; and a top electrode located on the surface of the gate tube material layer away from the bottom electrode. The bottom electrode material is one of nickel foam (Ni form), copper foam, metal nickel sheet, metal copper sheet, metal nickel film and metal copper film; the intermediate layer material is lithium nickel oxide Li x NiO 2‑δ (0<x≤1); the top electrode is either platinum or gold. The present invention's gate transistor, based on lithium nickel oxide, is form-free, exhibiting bidirectional threshold transition performance without requiring a forming process. It also exhibits stable threshold voltage and holding voltage. Used as a rectifying device, it can effectively suppress crosstalk current in RRAM memory arrays. The gate transistor of the present invention features a simple structure, simple process, and low cost.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor devices and integrated circuits, and particularly relates to a novel gate tube based on lithium nickel oxide material and a preparation method thereof. Background Art

[0002] With the continuous development of technologies such as cloud computing and artificial intelligence, application data is experiencing explosive growth, and the demand for information storage capabilities is increasing. To overcome the bottleneck of ultra-high-density integration technology imposed by the physical limitations of traditional flash memory, years of research have led to the development of a variety of new non-volatile storage technologies, such as phase-change memory, magnetic memory, ferroelectric memory, and resistive random access memory. Among these, resistive random access memory (RRAM) has become one of the most promising next-generation non-volatile memories due to its excellent performance, simple structure, and CMOS compatibility.

[0003] As the preferred solution for high-density storage, stacking memories in a cross-array structure theoretically achieves the highest integration density. However, this structure suffers from severe crosstalk, one of the most critical issues facing high-density integration, affecting device performance and causing information misreading. Therefore, to address this issue, the one-selector one-resistor (1S-1R) structure has been proposed. This utilizes the threshold transition characteristics of the selector, using it as a rectifying device, to effectively suppress crosstalk currents and enable large-scale array integration.

[0004] Similar to resistive random access memory (RRAM), gate transistors typically employ a sandwich structure with a transition layer formed between electrodes to achieve threshold transition characteristics. Currently, a new type of gate transistor based on Mott insulator materials (such as VO2 and NbO2) is gaining increasing attention in the memory industry. Transition metal oxides, such as niobium oxide, are widely used as gate devices in RRAM. Niobium oxide gate transistors have high nonlinearity and on-state current density, which can suppress crosstalk currents in RRAM memory arrays, thereby overcoming crosstalk issues. However, the on-off ratio of niobium oxide gate transistors is limited. Current research focuses on improving device performance by adding new dielectric layers, such as ZrO2 and MgO. However, this complicates the device structure and increases the difficulty of the manufacturing process, thereby limiting gate transistor performance. Therefore, developing new gate transistors with high gate performance and simple manufacturing processes is of great research and application value. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a gate transistor based on lithium nickel oxide material and a method for preparing the same. This gate transistor device has the advantages of simple structure, simple process, and low cost. To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] 1) A gate tube based on lithium nickel oxide material, comprising a bottom electrode (1), an intermediate layer material (2), and a top electrode (3) in close contact with each other in sequence;

[0007] The material of the bottom electrode (1) is one of foam nickel, foam copper, metal nickel sheet, metal copper, metal nickel film and metal copper film;

[0008] The intermediate layer material (2) is lithium nickel oxide Li x NiO 2-δ (0<x≤1) material;

[0009] The material of the top electrode (3) is one of metal platinum and metal gold.

[0010] 2) A method for preparing a novel gate tube based on lithium nickel oxide material, characterized in that the specific production steps are as follows:

[0011] (a) Clean and dry the bottom electrode;

[0012] (b) a 0.2 μm to 500 μm thick layer of Li-ion battery is prepared on the bottom electrode obtained above by slurry coating or thin film deposition. x NiO 2-δ (0<x≤1) intermediate layer; at the same time, a portion of the bottom electrode needs to be reserved on the bottom electrode; the thickness of the intermediate layer material should be controlled as needed during the coating or deposition process;

[0013] (c) drying the device obtained in step (b) at 100°C to 120°C for 20-60 minutes, and pressing it into a ceramic sheet using a tablet press. x NiO 2-δ (0<x≤1) the pressing thickness of the intermediate layer is controlled in the range of 0.1μm~200μm;

[0014] (d) A top electrode is prepared on the above device to obtain a gate tube based on lithium nickel oxide material.

[0015] The slurry preparation steps described in step (b) are:

[0016] Ⅰ): Use electronic balance to press Li x NiO 2-δ(0<x≤1) Weigh a certain proportion of LiOH·H2O and NiO2H2 powder, mix and grind them evenly, put them into a muffle furnace and heat them to 500-850℃ at a rate of 1-10℃ / min, sinter them for 4-9h, and obtain Li x NiO 2-δ (0<x≤1), and then ground into uniform powder;

[0017] Ⅱ): Powdered Li x NiO 2-δ (0<x≤1) and terpineol are mixed evenly in a mass ratio of 2:1-4:1 and set aside;

[0018] The method for preparing the top electrode in step (d) is any one of sputtering, evaporation, chemical vapor deposition, plasma enhanced chemical vapor deposition, low pressure chemical vapor deposition, metal compound vapor deposition, molecular beam epitaxy or atomic layer deposition.

[0019] In step (b), Li x NiO 2-δ The slurry coating method of the intermediate layer (0<x≤1) includes any one of spin coating, brush coating, spray coating, screen printing, and the like.

[0020] In step (b), Li x NiO 2-δ The thin film deposition method of the intermediate layer (0<x≤1) includes any one of electrochemical deposition, physical deposition and chemical deposition.

[0021] When using thin film deposition to prepare Li x NiO 2-δ When the intermediate layer is (0<x≤1), step (c) can be omitted or retained.

[0022] The beneficial effects of adopting the above technical solution are: the present invention selects a new gating material, proposes a gating tube with a new structure, and provides a simple method for preparing the gating tube.

[0023] Lithium nickel oxide (LiNiO) is used as the intermediate layer material for the gate tube. LiNiO exhibits phase change properties at high temperatures, enabling a reversible change in resistance under the combined action of an electric field and thermal effects, ensuring the high cycling stability of the LiNiO gate tube. Furthermore, compared to currently common gate tubes, which have very high requirements for the manufacturing process and thickness of the gate material, LiNiO gate tubes have lower manufacturing requirements, and the gate characteristics can be achieved over a wide range of lithium nickel oxide thickness differences. Therefore, LiNiO gate tubes are easier to manufacture and are less expensive.

[0024] The present invention proposes a gate transistor based on lithium nickel oxide material, which has the characteristics of forming-free. It can directly exhibit the performance of bidirectional threshold transition without the need for a forming process, the gate ratio can be greater than 10, and it has stable threshold voltage and holding voltage. It has the characteristics of simple structure, low process difficulty and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the cross-sectional structure of the gating tube of the present invention;

[0026] Among them, 1---bottom electrode; 2---Li x NiO 2-δ (0<x≤1) middle layer; 3---top electrode.

[0027] Figure 2 This is a 50-cycle IV performance curve of the gate tube of the present invention using LiNiO2 as the intermediate layer material, nickel foam as the bottom electrode, and Pt as the top electrode. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0029] Example 1:

[0030] 1) A Φ13x1.5 mm nickel foam disc was used as the bottom electrode. It was ultrasonically cleaned in a 3.0 mol.L-1 HCl solution for 20 min to remove the oxide layer on its surface. The nickel foam was removed and repeatedly rinsed with anhydrous ethanol and deionized water. Finally, it was ultrasonically cleaned in deionized water for 20 min. After removal, it was naturally dried and set aside.

[0031] 2) Use an electronic balance to press Li 0.8 NiO 2-δ Weigh a certain proportion of LiOH·H2O and NiO2H2 powder, mix and grind them evenly, put them into a muffle furnace and heat them to 700℃ at 10℃ / min, sinter them for 6h to obtain Li 0.8 NiO 2-δ (0<x≤1) and then grind into uniform powder; 0.8 NiO 2-δ Mix the mixture evenly with terpineol in a mass ratio of 2:1 and set aside;

[0032] 3) coating the slurry on the bottom electrode nickel foam cleaned and dried in step (1) by coating, and leaving a portion of the bottom electrode to dry at 120° C. to control the thickness of the intermediate layer material during the coating process;

[0033] 4) Then use a tablet press to press the Li-coated nickel foam support 0.8 NiO 2-δ The device is pressed into a ceramic sheet, and the obtained Li 0.8 NiO 2-δ The pressing thickness is about 150μm;

[0034] 5) Finally, a 100 nm thick platinum electrode is prepared on the side of the above device away from the bottom electrode by ion sputtering. The top electrode is rectangular or circular in shape, with a side length of 50 to 1000 μm and a diameter of 50 to 1000 μm, to obtain a new type of gating tube.

[0035] Example 2:

[0036] 1) Use a Φ13x2 mm nickel foam disc as the bottom electrode and ultrasonically clean it in a 3.0 mol.L-1 HCl solution for 20 min to remove the oxide layer on its surface. Remove the nickel foam and rinse it repeatedly with anhydrous ethanol and deionized water. Finally, immerse it in deionized water and ultrasonically clean it for 20 min. Remove it and let it dry naturally for later use.

[0037] 2) Use an electronic balance to weigh a certain proportion of LiOH*H2O and NiO2H2 powder according to LiNiO2, mix and grind evenly, put it into a muffle furnace and heat it to 700℃ at 10℃ / min, sinter it for 6h to obtain Li 0.8 NiO 2-δ (0<x≤1) and then grind into uniform powder; mix the powdered LiNiO2 and terpineol in a mass ratio of 3:1 and set aside;

[0038] 3) Screen printing the slurry onto the bottom electrode nickel foam that was cleaned and dried in step (1), and leaving a portion of the bottom electrode to dry at 120° C. During the printing process, the thickness of the intermediate layer material is controlled;

[0039] 4) The LiNiO2-coated device supported by nickel foam was then pressed into a ceramic sheet using a tablet press. The obtained LiNiO2 had a thickness of about 80 μm.

[0040] 5) Finally, an 80 nm thick platinum electrode is prepared by ion sputtering on the side of the above device away from the bottom electrode. The top electrode is rectangular or circular in shape, with a side length of the rectangle being 50 to 1000 μm and a diameter of the circle being 50 to 1000 μm, thereby obtaining a new gating tube.

[0041] The test results are attached. Figure 2 , it can be seen from the figure that it has a gating effect with obvious bidirectional threshold transition performance.

[0042] Example 3:

[0043] 1) Use a Φ13x1 mm copper foam disc as the bottom electrode and ultrasonically clean it in a 3.0 mol.L-1 HCl solution for 20 min to remove the oxide layer on its surface. Remove the nickel foam and rinse it repeatedly with anhydrous ethanol and deionized water. Finally, immerse it in deionized water and ultrasonically clean it for 20 min. Remove it and let it dry naturally for later use.

[0044] 2) Use an electronic balance to weigh a certain proportion of LiOH*H2O and NiO2H2 powder according to LiNiO2, mix and grind them evenly, put them in a muffle furnace and heat them to 700℃ at 10℃ / min, sinter them for 6h to obtain LiNiO2, and then grind them into uniform powder; mix the powdered LiNiO2 and terpineol in a mass ratio of 3:1 and set aside;

[0045] 3) The above slurry is printed on the bottom electrode nickel foam cleaned and dried in step (1) by screen printing, and a part of the bottom electrode is reserved and dried at 120°C. The thickness of the intermediate layer material is controlled during the printing process.

[0046] 4) The LiNiO2-coated device supported by nickel foam is then pressed into a ceramic sheet using a tablet press. The obtained LiNiO2 has a pressed thickness of about 50 μm.

[0047] 5) Finally, a 100 nm thick gold electrode is prepared on the side of the above device away from the bottom electrode by ion sputtering. The top electrode is rectangular or circular in shape, with a side length of 50 to 1000 μm and a diameter of 50 to 1000 μm, to obtain a new type of gating tube.

[0048] Example 4:

[0049] 1) A Φ13x1 mm nickel disc was used as the bottom electrode. It was ultrasonically cleaned in a 3.0 mol.L-1 HCl solution for 20 min to remove the oxide layer on its surface. The nickel foam was removed and repeatedly rinsed with anhydrous ethanol and deionized water. Finally, it was ultrasonically cleaned in deionized water for 20 min. After removal, it was naturally dried and set aside.

[0050] 2) Use an electronic balance to press Li 0.5 NiO 2-δ Weigh a certain proportion of LiOH*H2O and NiO2H2 powder, mix and grind them evenly, put them into a muffle furnace and heat them to 700℃ at 10℃ / min, sinter them for 6h to obtain Li 0.5 NiO 2-δ Grind into uniform powder; 0.5 NiO 2-δ Mix the mixture evenly with terpineol in a mass ratio of 4:1 and set aside;

[0051] 3) The above slurry is printed on the bottom electrode nickel foam cleaned and dried in step (1) by screen printing, and a part of the bottom electrode is reserved and dried at 120°C. The thickness of the intermediate layer material is controlled during the printing process.

[0052] 4) Then use a tablet press to press the Li-coated nickel foam support 0.5 NiO 2-δ The device is pressed into a ceramic sheet, and the obtained Li 0.5 NiO 2-δ The pressing thickness is about 100μm;

[0053] 5) Finally, a 100 nm thick gold electrode is prepared on the side of the above device away from the bottom electrode by ion sputtering. The top electrode is rectangular or circular in shape, with a side length of 50 to 1000 μm and a diameter of 50 to 1000 μm, to obtain a new type of gating tube.

[0054] Performance testing:

[0055] The gate transistor devices prepared in Examples 1 and 2 were subjected to IV tests respectively. The tests were performed on an Agilent B1500A semiconductor parameter analyzer test platform. Here, the gate transistor device in Example 2 is mainly described in detail.

[0056] Two probes are respectively in contact with the top electrode and the bottom electrode of the gate tube device in Example 2, wherein the end in contact with the top electrode is at a negative voltage. Using the Agilent B1500A test software, a -10V to 10V DC scanning voltage is applied to the top electrode, the top electrode is grounded, and the IV curve is measured. A scanning voltage cycle includes four parts: first scanning from 0 to +10V, then scanning from +10V to 0, then scanning in reverse, scanning from 0 to -10V, and then scanning from -10V to 0, that is, completing a scanning cycle, and the number of scanning steps in each part is the same. In order to prevent the device from being broken down due to excessive current during the test, a limiting current (I CC =7mA).

[0057] Depend on Figure 2It can be seen that the gating ratio of the gating tube device is about 32, and it has a gating effect with obvious bidirectional threshold transition performance. The cycle curves basically overlap with each other, the distribution is concentrated, and the IV curve has excellent electrical cycle stability. For positive scanning, when the scanning voltage is greater than the threshold voltage of the gating tube device, the gating tube device is turned on, and the device switches from a high-resistance state to a low-resistance state; when the scanning voltage scans back to the holding voltage of the gating tube device, the gating tube device is turned off and returns to a high-resistance state. For negative scanning, when the scanning voltage is greater than the threshold voltage of the gating tube device, the gating tube device is turned on, and the device switches from a high-resistance state to a low-resistance state; when the scanning voltage scans back to the holding voltage of the gating tube device, the gating tube device is turned off and returns to a high-resistance state. Figure 2 As can be seen in the figure, the threshold voltage of the gate transistor of the present invention is approximately 5.8V. When the voltage is scanned before the threshold voltage, as the voltage applied to the gate transistor increases, the current of the device decreases, and the device is in a high-impedance state. Only when the voltage reaches the threshold voltage does the current of the device suddenly increase, and the on-state current can reach 7mA, indicating a transition to a low-impedance state. When the voltage drops below the holding voltage, the device immediately returns to the high-impedance state, meaning that the gate transistor is turned off.

[0058] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A gate tube based on lithium nickel oxide material, comprising a bottom electrode (1), an intermediate layer material (2), and a top electrode (3) in close contact with each other, characterized in that: The material of the bottom electrode (1) is one of foam nickel, foam copper, metal nickel sheet, metal copper sheet, metal nickel film and metal copper film; The intermediate layer material (2) is lithium nickel oxide Li x NiO 2-δ , where 0.5≤x≤1; The material of the top electrode (3) is one of metal platinum and metal gold; The gate tube is a gate tube with bidirectional threshold switching characteristics; The preparation method of the gate tube comprises the following steps: (a) Clean and dry the bottom electrode; (b) A 0.2 μm to 500 μm thick layer of Li-ion battery is prepared on the bottom electrode obtained above by slurry coating or thin film deposition. x NiO 2-δ Intermediate layer; at the same time, a portion of the bottom electrode needs to be reserved on the bottom electrode; the thickness of the intermediate layer material should be controlled as needed during the coating or deposition process; (c) The device obtained in step (b) is dried at 100°C to 120°C for 20-60 minutes and then pressed into a ceramic sheet using a tablet press. x NiO 2-δ The pressing thickness of the middle layer is controlled in the range of 0.1 μm to 200 μm; (d) A top electrode is fabricated on the above device to obtain a gate transistor based on lithium nickel oxide material.

2. A method for preparing a gate tube based on lithium nickel oxide material according to claim 1, characterized in that The specific production steps are as follows: (a) Clean and dry the bottom electrode; (b) A 0.2 μm to 500 μm thick layer of Li-ion battery is prepared on the bottom electrode obtained above by slurry coating or thin film deposition. x NiO 2-δ Intermediate layer; at the same time, a portion of the bottom electrode needs to be reserved on the bottom electrode; the thickness of the intermediate layer material should be controlled as needed during the coating or deposition process; (c) The device obtained in step (b) is dried at 100°C to 120°C for 20-60 minutes and then pressed into a ceramic sheet using a tablet press. x NiO 2-δ The pressing thickness of the middle layer is controlled in the range of 0.1 μm to 200 μm; (d) A top electrode is fabricated on the above device to obtain a gate transistor based on lithium nickel oxide material; Among them, 0.5≤x≤1.

3. The method for preparing a gate tube based on lithium nickel oxide material according to claim 2, characterized in that: The slurry preparation steps described in step (b) are: Ⅰ): Use electronic balance to press Li x NiO 2-δ Weigh a certain proportion of LiOH·H2O and NiO2H2 powder, mix and grind evenly, put it into a muffle furnace and heat it to 500-850 ℃ at a rate of 1-10 ℃ / min, sinter it for 4-9 h, and obtain Li x NiO 2-δ , and then grind into uniform powder; Ⅱ): Powdered Li x NiO 2-δ and terpineol in a mass ratio of 2:1-4:1 and mix well for later use.

4. The method for preparing a gate tube based on lithium nickel oxide material according to claim 2, characterized in that: The method for preparing the top electrode in step (d) is any one of sputtering, evaporation, chemical vapor deposition, plasma enhanced chemical vapor deposition, low pressure chemical vapor deposition, metal compound vapor deposition, molecular beam epitaxy or atomic layer deposition.

5. The method for preparing a gate tube based on lithium nickel oxide material according to claim 2, characterized in that: Li in step (b) x NiO 2-δ The slurry coating method for the intermediate layer includes any one of spin coating, brush coating, spray coating, and screen printing.

6. The method for preparing a gate tube based on lithium nickel oxide material according to claim 2, characterized in that: Li in step (b) x NiO 2-δ The thin film deposition method of the intermediate layer includes any one of electrochemical deposition, physical deposition and chemical deposition.

7. The method for preparing a gate tube based on lithium nickel oxide material according to claim 2, characterized in that: When using thin film deposition to prepare Li x NiO 2-δ When the intermediate layer is used, step (c) is omitted or retained.

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