A method for manufacturing a memristor
By fabricating a heterojunction memristor of cuprous phosphide and zinc oxide on a silicon substrate, the problem of poor performance of zinc oxide-based memristors was solved, achieving low-voltage low-resistance, high-voltage high-resistance switching characteristics and high stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HANGZHOU DIANZI UNIV
- Filing Date
- 2022-05-16
- Publication Date
- 2026-06-16
AI Technical Summary
Existing zinc oxide-based memristors have poor performance, and there is insufficient research on bilayer memristors with different conductivity types.
A bilayer memristor was fabricated using cuprous phosphide and zinc oxide. Gold electrodes, copper films, zinc oxide films, and silver electrodes were deposited on a silicon substrate by thermal evaporation and magnetron sputtering to form a heterojunction structure of p-type and n-type materials.
It achieves the switching characteristics of memristors, which are low-resistance under low voltage and high-resistance under high voltage, with a switching voltage of 0.3-0.4 V, low power consumption, large switching ratio, and high device stability.
Smart Images
Figure CN114944454B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of materials and devices technology, and specifically relates to a method for preparing a memristor. Background Technology
[0002] Zinc oxide is a wide-bandgap semiconductor material with excellent photoelectric and luminescent properties. It has also been applied in memristor research, but zinc oxide-based memristors fabricated with different structures and processes exhibit significantly different and sometimes poor performance. Compared to single-layer semiconductor materials, memristors fabricated with bilayer materials have different working mechanisms and may exhibit better performance. This patent argues that bilayer memristors fabricated with different conductivity types will exhibit superior performance compared to bilayer memristors fabricated with the same conductivity type. Cuprous phosphide is typically a p-type material, while zinc oxide is an n-type material. This patent fabricates a zinc oxide / cuprous phosphide bilayer memristor by preparing zinc oxide on the surface of cuprous phosphide. This memristor exhibits performance different from typical memristors; as the voltage increases, the resistance changes from low to high, and upon reversing the voltage application, it returns from a high-resistance state to a low-resistance state. Summary of the Invention
[0003] This invention addresses the shortcomings of existing research by proposing a method for preparing memristors based on zinc oxide and cuprous phosphide.
[0004] The present invention first thermally deposits a gold electrode on a silicon substrate, then prepares a cuprous phosphide thin film on the surface of the gold electrode, then prepares a zinc oxide thin film on the surface of the cuprous phosphide, and finally deposits a silver electrode on the surface of the zinc oxide thin film.
[0005] This invention discloses a method for fabricating a memristor, which specifically includes the following steps:
[0006] Step (1). A gold thin film with a thickness of 200-1000 nm is deposited on the surface of a silicon substrate by thermal evaporation. The gold thin film serves as the gold electrode.
[0007] Step (2). The product from step (1) is deposited with a copper thin film by thermal evaporation, with a copper film thickness of 1-100 micrometers;
[0008] Step (3). The product from step (2) and red phosphorus or sodium thiosulfate are placed together in an alumina tube under an argon protective atmosphere and heated to 280-300 °C at a heating rate of 10 °C / min. After the temperature reaches 280-300 °C, it is held for 30-60 min. Then it is naturally cooled to room temperature. The alumina tube is evacuated to remove residual gas. Then the substrate with cuprous phosphide grown on the surface of the product is taken out.
[0009] Step (4). Using the product from step (3) as a substrate, deposit a zinc oxide thin film by magnetron sputtering;
[0010] Step (5). On the surface of the zinc oxide film produced in step (4), a silver electrode is deposited by thermal evaporation; the vacuum degree of the thermal evaporation equipment is 5×10⁻⁶. -4 Pa, deposition rate 20 nm / min.
[0011] Preferably, the corundum tube is heated to 280°C using a tube furnace.
[0012] Preferably, the silicon substrate is replaced with a glass substrate or a sapphire substrate.
[0013] Preferably, the gold electrode is replaced with a platinum electrode.
[0014] Preferably, the silver electrode is replaced with a gold, platinum, titanium, aluminum, copper, silver, or ITO conductive glass electrode.
[0015] Preferably, the zinc oxide thin film is prepared by laser pulse deposition.
[0016] Preferably, the oxide film is replaced with titanium dioxide.
[0017] Preferably, in the magnetron sputtering method, the magnetron sputtering equipment has a vacuum degree of 0.1-1.0 Pa, an oxygen flow rate of 1-5 sccm, an argon flow rate of 20-50 sccm, a sputtering voltage of 300-450 V, a current of 30-60 mA, a sputtering time of 60-120 min, and a zinc target; the prepared zinc oxide film has a thickness of 500-1000 nm.
[0018] The advantages of this invention are: the memristor prepared from p-type cuprous phosphide and n-type zinc oxide has a different working mechanism than that prepared from single cuprous phosphide or zinc oxide, and its performance is improved. Unlike general memristors, this device is in a low-resistance state (on state) under low voltage and a high-resistance state (off state) under high voltage, with a switching voltage of 0.3-0.4 V, low power consumption, large switching ratio, and high device stability. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the structure obtained by the present invention;
[0020] Figure 2 This is the current-voltage characteristic diagram of the present invention. Detailed Implementation
[0021] Example 1:
[0022] Step (1). A gold thin film with a thickness of 200 nm is deposited on the surface of a silicon substrate by thermal evaporation. The gold thin film serves as the gold electrode.
[0023] Step (2). The product from step (1) is deposited with a copper thin film by thermal evaporation, and the copper thin film thickness is 2 micrometers.
[0024] Step (3). The product from step (2) and red phosphorus are placed together in an alumina tube under an argon protective atmosphere and heated to 280 ℃ at a heating rate of 10 ℃ / min. After the temperature reaches 280 ℃, it is held for 30 min. Then it is naturally cooled to room temperature. The alumina tube is evacuated to remove residual gas. Then the substrate with cuprous phosphide grown on the surface of the product is taken out.
[0025] Step (4). Using the product from step (3) as a substrate, a zinc oxide thin film is deposited by magnetron sputtering. In the magnetron sputtering method, the vacuum degree of the magnetron sputtering equipment is 0.1 Pa, the oxygen flow rate is 1 sccm, the argon flow rate is 20 sccm, the sputtering voltage is 300 V, the current is 30 mA, the sputtering time is 60 min, and the target material is a metallic zinc target. The thickness of the prepared zinc oxide thin film is 500 nm.
[0026] Step (5). On the surface of the zinc oxide film produced in step (4), a silver electrode is deposited by thermal evaporation; the vacuum degree of the thermal evaporation equipment is 5×10⁻⁶. -4 Pa, deposition rate 20 nm / min.
[0027] like Figure 1 The diagram shows the structure of a memristor, and the obtained current-voltage characteristics of the memristor are as follows. Figure 2 As shown, this memristor is in a low-resistance state under low voltage and a high-resistance state under high voltage. It has a switching voltage of 0.3 V, low power consumption, large switching ratio, and high device stability.
[0028] Example 2:
[0029] Step (1). A platinum thin film with a thickness of 500 nm is deposited on the surface of a glass substrate by thermal evaporation. The platinum thin film serves as a platinum electrode.
[0030] Step (2). The product from step (1) is deposited with a copper thin film by thermal evaporation, with a copper film thickness of 50 micrometers;
[0031] Step (3). The product from step (2) and red phosphorus are placed together in an alumina tube under an argon protective atmosphere and heated to 290 °C at a heating rate of 10 °C / min. After the temperature reaches 290 °C, it is held for 40 min. Then it is naturally cooled to room temperature. The alumina tube is evacuated to remove residual gas. Then the substrate with cuprous phosphide grown on the surface of the product is taken out.
[0032] Step (4). Using the product from step (3) as a substrate, a zinc oxide thin film is deposited by magnetron sputtering. In the magnetron sputtering method, the vacuum degree of the magnetron sputtering equipment is 0.7 Pa, the oxygen flow rate is 3 sccm, the argon flow rate is 40 sccm, the sputtering voltage is 400V, the current is 50 mA, the sputtering time is 90 min, and the target material is a metallic zinc target. The thickness of the prepared zinc oxide thin film is 800 nm.
[0033] Step (5). On the surface of the zinc oxide film produced in step (4), a gold electrode is deposited by thermal evaporation; the vacuum degree of the thermal evaporation equipment is 5×10⁻⁶. -4 Pa, deposition rate 20 nm / min.
[0034] Example 3:
[0035] Step (1). A gold film with a thickness of 1000 nm is deposited on the surface of a sapphire substrate by thermal evaporation. The gold film serves as the gold electrode.
[0036] Step (2). The product from step (1) is deposited with a copper thin film by thermal evaporation, with a copper film thickness of 100 micrometers;
[0037] Step (3). The product from step (2) and red phosphorus are placed together in an alumina tube under an argon protective atmosphere and heated to 300 ℃ at a heating rate of 10 ℃ / min. After the temperature reaches 300 ℃, it is held for 60 min. Then it is naturally cooled to room temperature. The alumina tube is evacuated to remove residual gas. Then the substrate with cuprous phosphide grown on the surface of the product is taken out.
[0038] Step (4). Using the product from step (3) as a substrate, a zinc oxide thin film is deposited by magnetron sputtering. In the magnetron sputtering method, the vacuum degree of the magnetron sputtering equipment is 1.0 Pa, the oxygen flow rate is 5 sccm, the argon flow rate is 50 sccm, the sputtering voltage is 450V, the current is 60 mA, the sputtering time is 120 min, and the target material is a metallic zinc target. The thickness of the prepared zinc oxide thin film is 1000 nm.
[0039] Step (5). A copper electrode is deposited on the surface of the zinc oxide film produced in step (4) by thermal evaporation; the vacuum degree of the thermal evaporation equipment is 5×10⁻⁶. -4 Pa, deposition rate 20 nm / min.
Claims
1. A method for fabricating a memristor, characterized in that, The method specifically includes the following steps: Step (1). A gold thin film with a thickness of 200-1000 nm is deposited on the surface of a silicon substrate by thermal evaporation. The gold thin film serves as the gold electrode. Step (2). The product from step (1) is deposited with a copper thin film by thermal evaporation, with a copper film thickness of 1-100 micrometers; Step (3). The product from step (2) and red phosphorus are placed together in an alumina tube under an argon protective atmosphere and heated to 280-300 °C at a heating rate of 10 °C / min. After the temperature reaches 280-300 °C, it is held for 30-60 min. Then it is naturally cooled to room temperature. The alumina tube is evacuated to remove residual gas. Then the substrate with cuprous phosphide grown on the surface of the product is taken out. Step (4). Using the product from step (3) as a substrate, deposit a zinc oxide thin film by magnetron sputtering; Step (5). On the surface of the zinc oxide film produced in step (4), a silver electrode is deposited by thermal evaporation; the vacuum degree of the thermal evaporation equipment is 5×10⁻⁶. -4 Pa, deposition rate 20 nm / min.
2. The method for fabricating a memristor according to claim 1, characterized in that: The corundum tube is heated to 280°C in a tube furnace.
3. The method for fabricating a memristor according to claim 1, characterized in that: The silicon substrate is replaced with a glass substrate or a sapphire substrate.
4. The method for fabricating a memristor according to claim 1, characterized in that: The gold electrode was replaced with a platinum electrode.
5. The method for fabricating a memristor according to claim 1, characterized in that: The silver electrode is replaced with one of the following: gold, platinum, titanium, aluminum, copper, or ITO conductive glass electrode.
6. The method for fabricating a memristor according to claim 1, characterized in that: The zinc oxide thin film was prepared by laser pulse deposition.
7. The method for fabricating a memristor according to claim 1, characterized in that: The zinc oxide film was replaced with titanium dioxide.
8. The method for fabricating a memristor according to claim 1, characterized in that: In the magnetron sputtering method, the magnetron sputtering equipment has a vacuum degree of 0.1-1.0 Pa, an oxygen flow rate of 1-5 sccm, an argon flow rate of 20-50 sccm, a sputtering voltage of 300-450 V, a current of 30-60 mA, a sputtering time of 60-120 min, and a zinc target. The prepared zinc oxide thin film has a thickness of 500-1000 nm.