Asymmetric Schottky barrier modulated memristor transistor based on two-dimensional material and preparation method and application of asymmetric Schottky barrier modulated memristor transistor
By designing an asymmetric Schottky barrier structure in the memristor transistor, the problem of insufficient anti-crosstalk capability of existing memristor transistors is solved, and high rectification characteristics and conductivity are achieved, which are suitable for applications such as neuromorphic computing and memory computing.
Patent Information
- Application Number
- CN202410176505.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-08
- Publication Date
- 2025-08-08
AI Technical Summary
The Schottky barrier structure symmetry of existing memristor transistors leads to insufficient anti-crosstalk capability, affecting signal crosstalk problems during array integration.
Memristor transistors based on two-dimensional materials are designed to form asymmetric Schottky barrier contact by using metals of different work functions at the source and drain electrodes, and high rectification characteristics and nonvolatileness are achieved through the gate voltage controlling the conductivity characteristics of the device.
It improves the anti-crosstalk capability of memristor transistors, realizes high rectification modulation between devices and continuous tunability of conductance, and is suitable for fields such as neuromorphic computing and memory computing.
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Figure CN120456809A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of semiconductor devices and neuromorphic devices, and specifically relates to a memristor transistor with asymmetric Schottky barrier modulation based on two-dimensional materials, and a preparation method and application thereof. Background Art
[0002] As the amount of data generated by society increases dramatically and the complexity of its data types increases, the efficiency of neural network-based information processing models will significantly surpass that of traditional von Neumann architecture computers. Therefore, the development of electronic devices that integrate storage and computing with the characteristics of neuromorphic architectures has become a key direction for the future development of information technology.
[0003] Neuromorphic devices are essential hardware platforms for neuromorphic computing and a key technology for building neuromorphic chips. Based on the number of input ports, neuromorphic devices can be categorized as two-terminal, three-terminal, and multi-terminal. Two-terminal devices include phase-change memory and memristors; three-terminal devices include ferroelectric transistors and organic field-effect transistors; and multi-terminal devices include memristor transistors.
[0004] Traditional memristors are two-terminal devices whose operating mechanism involves the distribution of internal ions or vacancies, achieving significant changes in conductivity by forming and breaking conductive fibers connecting two electrodes. However, memristive devices suffer from instability and crosstalk between cells. In recent years, researchers have conducted research on memristive transistors. Their typical structure is a three-terminal transistor. By applying a voltage at the drain to induce a nonvolatile change in channel resistance and turning the device on and off with a voltage at the gate, they combine the memory function of a memristor with the control function of a transistor. While memristive transistors exhibit unique synaptic and conductive plasticity, the symmetrical Schottky barrier structure between their source and drain electrodes reduces their crosstalk resistance, making them vulnerable to signal crosstalk caused by leakage current between cells when integrated into arrays. In this context, developing memristive transistors with asymmetric Schottky barrier modulation, which improves their rectification properties and thus crosstalk resistance, is an important step in advancing neuromorphic devices. Summary of the Invention
[0005] The purpose of the present invention is to propose a novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials and a preparation method thereof, based on the problem that current memristor transistor devices lack rectification characteristics. Its applications involve signal processing, high-resolution imaging, physical neural networks, neuromorphic computing and memory computing.
[0006] The technical solutions of the present invention are as follows:
[0007] A memristor transistor with asymmetric Schottky barrier modulation based on two-dimensional materials, comprising:
[0008] substrate;
[0009] Two-dimensional semiconductor material on a substrate;
[0010] The source electrode and the drain electrode are respectively on the two-dimensional semiconductor material;
[0011] The gate oxide layer is above the source and drain electrodes;
[0012] The gate electrode is above the gate oxide layer;
[0013] Its characteristics are: by constructing a horizontal short-channel memristor transistor device on a two-dimensional semiconductor crystal with atomic-level thickness; by adjusting the type of metal electrodes that match the source electrode and the drain electrode, an asymmetric Schottky barrier contact with one end high and the other end low is formed at both ends of the memristor transistor to achieve high rectification characteristics; applying voltage to the source and drain electrodes drives the movement of defects such as vacancies in the short channel of the two-dimensional semiconductor material to achieve the non-volatile characteristics of the device; by controlling the gate voltage, the conductance of the memristor transistor device under gate control is continuously adjustable.
[0014] Preferably, the thickness of the short channel is less than 1 nm.
[0015] Preferably, the type of the metal electrode for adjusting and matching the source electrode and the drain electrode is specifically:
[0016] At the high Schottky barrier end, a metal with a high work function, such as platinum or palladium, is used to form a high contact potential difference;
[0017] At the low Schottky barrier end, a low work function metal or semi-metal, such as indium, bismuth, antimony or bismuth-antimony alloy, is used to form a low contact potential difference and eliminate the Fermi pinning effect, thereby obtaining a lower Schottky barrier or ohmic contact;
[0018] The following matching method is adopted: platinum or palladium is selected at the source electrode, and indium, bismuth, antimony or bismuth-antimony alloy is selected at the drain electrode; or indium, bismuth, antimony or bismuth-antimony alloy is selected at the source electrode, and platinum or palladium is selected at the drain electrode.
[0019] Preferably, the control gate voltage is specifically:
[0020] The source is grounded, a bias is applied to the drain, and the bias increases from 0V to a positive value Vds, then decreases from Vds to 0V, decreases from 0V to -Vds, and then increases from -Vds to 0V, sequentially realizing four resistance changes of forward high resistance state, forward low resistance state, reverse high resistance state, and reverse low resistance state, thereby realizing the non-volatile storage characteristics of the memristor.
[0021] By adjusting the gate bias, the carrier concentration in the channel is effectively controlled, achieving continuously adjustable channel conductance. Simultaneously, the gate voltage also regulates the Schottky barrier height of the electrode contact, optimizing and improving the device's rectification characteristics. Preferably, the substrate is glass, aluminum oxide, or silicon oxide.
[0022] Preferably, the two-dimensional semiconductor material is a single atomic layer of transition metal chalcogenides such as molybdenum sulfide, tungsten sulfide, and rhenium sulfide;
[0023] Preferably, the gate oxide layer is made of a high dielectric constant material, including aluminum oxide, hafnium oxide or zirconium oxide.
[0024] Preferably, the gate electrode is gold, platinum, titanium or chromium.
[0025] On the other hand, the present invention also provides a method for preparing a novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials, which is characterized in that the method comprises:
[0026] Step 1: Transfer or grow a single layer of two-dimensional semiconductor material on a substrate;
[0027] Step 2: Form the drain electrode region by photolithography, use an ultra-high vacuum electron beam evaporator to evaporate a layer of high work function metal, and form the drain electrode after stripping;
[0028] Step 3: Precisely overlay to form the drain electrode area, using ultra-high vacuum electron beam evaporation or molecular beam epitaxy to evaporate a layer of low work function metal, and then remove the resist to form the drain electrode;
[0029] Step 4: growing a gate oxide layer using atomic layer deposition;
[0030] Step 5: Precisely overlay to form the gate electrode area, use an ultra-high vacuum electron beam evaporator to evaporate a layer of gate metal, and then remove the glue to form the gate electrode;
[0031] or
[0032] Step 1: Transfer or grow a single layer of two-dimensional semiconductor material on a substrate;
[0033] Step 2: Form the source region by photolithography, use ultra-high vacuum electron beam evaporation to evaporate a layer of high work function metal, and form the source electrode after desmearing;
[0034] Step 3: Precisely overlay to form the drain electrode area, using ultra-high vacuum electron beam evaporation or molecular beam epitaxy to evaporate a layer of low work function metal, and then remove the resist to form the drain electrode;
[0035] Step 4: growing a gate oxide layer using atomic layer deposition;
[0036] Step 5: Accurately overlay to form the gate electrode area, use an ultra-high vacuum electron beam evaporator to evaporate a layer of gate metal, and form the gate electrode after degumming.
[0037] Preferably, in step 1, the substrate is ultrasonically cleaned with acetone, isopropyl alcohol and deionized water in sequence, and then blown dry with a nitrogen gun.
[0038] At the same time, the present invention also provides applications of the above-mentioned asymmetric Schottky barrier modulated memristor based on two-dimensional materials in signal processing, high-resolution imaging, physical neural networks, neuromorphic computing and memory computing.
[0039] The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials and the preparation method thereof of the present invention have the following beneficial effects:
[0040] 1. By constructing a three-terminal memristor device, the non-volatility, cycling stability, and adjustable gate conductance of the memristor are achieved.
[0041] 2. By regulating the metal types of the source and drain electrodes, an asymmetric Schottky barrier is achieved at the source and drain electrodes of the device, achieving high rectification modulation of the device, which can effectively suppress the dark current between devices and improve the anti-crosstalk capability of the memristor transistor array.
[0042] 3. The atomic layer deposition method can be carried out at temperatures below 400 degrees Celsius, effectively reducing the process temperature during device preparation.
[0043] 4. The use of a single layer of transition metal chalcogenides can effectively shorten the physical limit size of device features.
[0044] 5. The use of glass or transparent rigid substrate can have a good early application in integrated current fields such as system panels. BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Figure 1 Schematic diagram of the structure of a new type of asymmetric Schottky barrier modulation memristor based on two-dimensional materials;
[0046] Figure 2 A microscope photo of the device array;
[0047] Figure 3 is a device diagram of the main process steps in the device preparation process, where:
[0048] Figure 3a A schematic cross-sectional view of transferring or growing a two-dimensional material on a substrate;
[0049] Figure 3b A process step for forming an electrode at one end of a transistor;
[0050] Figure 3cA process step for forming an electrode at the other end of the transistor;
[0051] Figure 3d The process step of forming a gate oxide layer;
[0052] Figure 3e A process step for forming a transistor gate electrode.
[0053] Figure 4 is the memristive cycling characteristic of the device.
[0054] Figure 5 It is used to control the drain conductance of the device.
[0055] Figure 6 is the rectification ratio of the device. DETAILED DESCRIPTION
[0056] The present invention will be further described in detail below with reference to specific examples in conjunction with the accompanying drawings.
[0057] The present invention provides a novel asymmetric Schottky barrier modulated memristor transistor device based on two-dimensional materials. Figure 1 A schematic diagram of the device structure.
[0058] like Figure 4 As shown in the figure, a scanning voltage is applied to the source and drain electrodes, and the scanning process is: 0V→maximum positive voltage→0V→minimum negative voltage→0V; in the four processes, the device respectively exhibits high configuration, low resistance state, low resistance state, and high configuration, thus realizing the function of memristor. Figure 5 As shown in Figure 2, by applying voltage to the gate, the channel conductance can be effectively controlled. Figure 6 As shown, the device exhibits modulatable rectification characteristics under different gate voltages.
[0059] Figure 1 As shown, the novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials of the present invention comprises: a substrate 1, a two-dimensional semiconductor material 2, a source electrode 3 and a drain electrode 4, a gate oxide layer 5, and a gate electrode 6, wherein:
[0060] The two-dimensional semiconductor material 2 is on the substrate 1; the source electrode 3 and the drain electrode 4 are respectively on the two-dimensional semiconductor material 2; the gate oxide layer 5 is on the source electrode 3 and the drain electrode 4; and the gate electrode 6 is on the gate oxide layer 5.
[0061] The substrate 1 is made of glass, aluminum oxide or silicon oxide.
[0062] The two-dimensional semiconductor material 2 is a single layer of large area (greater than 2 inches) of molybdenum sulfide, tungsten sulfide, or rhenium sulfide.
[0063] The source electrode 3 is made of bismuth, antimony or bismuth-antimony alloy.
[0064] The drain electrode 4 is made of platinum, palladium or a platinum-palladium alloy.
[0065] The gate oxide layer 5 is made of a high dielectric constant material, such as aluminum oxide, hafnium oxide or zirconium oxide.
[0066] The gate electrode 6 is made of gold, platinum, titanium or chromium.
[0067] The method for preparing the novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials described in claim 1 is characterized in that the method comprises:
[0068] Step 1: Grow or transfer a large area of a single layer of MoS2 film 2 on a substrate 1. Figure 3a As shown, the source electrode region is formed by photolithography.
[0069] Step 2: Use ultra-high vacuum electron beam evaporator to evaporate 20nm bismuth and 30nm Au, and form source electrode 3 after removing the glue, as shown in the following figure: Figure 3b shown.
[0070] Step 3: The drain electrode region is formed by precise overlay. The length of the channel of the prepared device is about 200 nanometers and the width is about 10 micrometers. 20nm platinum and 30nm Au are evaporated using an ultra-high vacuum electron beam evaporator or molecular beam epitaxy. After debonding, the drain electrode 4 is formed. Figure 3c shown.
[0071] Step 4: Grow a 30nm aluminum oxide gate oxide layer 5 using atomic layer deposition, such as Figure 3d shown.
[0072] Step 5: Use precise overlay to form the gate electrode area, use ultra-high vacuum electron beam evaporation to evaporate 10nm Ti and 30nm Au gate metal, and form the gate electrode 4 after stripping. Figure 3e shown.
[0073] Another method for preparing the novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials as described in claim 1 is characterized in that the method comprises:
[0074] Step 1: Grow or transfer a single layer of tungsten disulfide film 2 on a substrate 1. Figure 3a As shown, the electrode area is formed by photolithography. Step 2: Use ultra-high vacuum electron beam evaporation to evaporate 20nm palladium and 30nm gold, and after stripping, form electrode 3, as shown Figure 3b shown.
[0075] Step 3: Form another electrode region by precise overlay. The channel length of the prepared device is about 200 nanometers and the width is about 10 micrometers. Use ultra-high vacuum electron beam evaporation or molecular beam epitaxy to evaporate 20nm bismuth and 30nm gold. After degumming, form electrode 4. Figure 3c shown.
[0076] Step 4: Grow a 30nm hafnium oxide gate oxide layer 5 by atomic layer deposition, as shown in FIG. Figure 3d shown.
[0077] Step 5: Use precise overlay to form the gate electrode area, use ultra-high vacuum electron beam evaporator to evaporate 10nm chromium and 30nm gold gate metal, and form gate electrode 4 after degumming. Figure 3e shown.
[0078] The present invention has been described in detail through the above examples, but it should be appreciated that the above description should not be considered as limiting the present invention. Therefore, the protection scope of the present invention should be defined by the appended claims.
Claims
1. A memristor transistor with asymmetric Schottky barrier modulation based on two-dimensional materials, comprising: substrate (1); A two-dimensional semiconductor material (2) is on a substrate (1); The source electrode (3) and the drain electrode (4) are respectively on the two-dimensional semiconductor material (2); A gate oxide layer (5) is above the source electrode (3) and the drain electrode (4); A gate electrode (6) is on the gate oxide layer (5); Its characteristics are: By constructing a horizontal short-channel memristor transistor device on a two-dimensional semiconductor crystal with atomic-level thickness; by adjusting the type of metal electrodes that match the source electrode and the drain electrode, an asymmetric Schottky barrier contact with one end high and the other end low is formed at both ends of the memristor transistor to achieve high rectification characteristics; applying voltage to the source and drain electrodes drives the movement of defects such as vacancies in the short channel of the two-dimensional semiconductor material, realizing the non-volatile characteristics of the device; and by controlling the gate voltage, the continuously adjustable conductivity characteristics of the memristor transistor device under gate control are achieved.
2. The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to claim 1, characterized in that: The thickness of the short channel is less than 1 nm.
3. The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to claim 1, characterized in that: The type of metal electrode for adjusting and matching the source electrode and the drain electrode is specifically: At the high Schottky barrier end, a metal with a high work function, such as platinum or palladium, is used to form a high contact potential difference; At the low Schottky barrier end, a low work function metal or semi-metal, such as indium, bismuth, antimony or bismuth-antimony alloy, is used to form a low contact potential difference and eliminate the Fermi pinning effect, thereby obtaining a lower Schottky barrier or ohmic contact; The following matching method is adopted: platinum or palladium is selected at the source electrode, and indium, bismuth, antimony or bismuth-antimony alloy is selected at the drain electrode; or indium, bismuth, antimony or bismuth-antimony alloy is selected at the source electrode, and platinum or palladium is selected at the drain electrode.
4. The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to claim 1, characterized in that: The control gate voltage is specifically: The source (3) is grounded, and a bias voltage is applied to the drain (4). The bias voltage increases from 0V to a positive value Vds, then decreases from Vds to 0V, decreases from 0V to -Vds, and then increases from -Vds to 0V, thereby sequentially realizing four resistance value changes of a forward high resistance state, a forward low resistance state, a reverse high resistance state, and a reverse low resistance state, thereby realizing the non-volatile storage characteristics of the memristor. By adjusting the gate (6) bias voltage, the carrier concentration in the channel is effectively regulated to achieve the continuously adjustable characteristics of the channel conductance. At the same time, the gate voltage also regulates the Schottky barrier height of the electrode contact to achieve the optimization and improvement of the device rectification characteristics.
5. The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to claim 1, characterized in that: The substrate (1) is glass, aluminum oxide or silicon oxide.
6. The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to claim 1, characterized in that: The two-dimensional semiconductor material (2) is a single atomic layer of transition metal sulfide such as molybdenum sulfide, tungsten sulfide, rhenium sulfide, etc.
7. The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to claim 1, characterized in that: The gate oxide layer (5) is made of a high dielectric constant material, including aluminum oxide, hafnium oxide or zirconium oxide.
8. The novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to claim 1, characterized in that: The gate electrode (6) is made of gold, platinum, titanium or chromium.
9. A method for preparing a novel asymmetric Schottky barrier modulated memristor based on two-dimensional materials, characterized in that: The method includes: Step 1: Transfer or grow a single layer of two-dimensional semiconductor material on a substrate; Step 2: Form the drain electrode region by photolithography, use an ultra-high vacuum electron beam evaporator to evaporate a layer of high work function metal, and form the drain electrode after stripping; Step 3: Precisely overlay to form the drain electrode area, using ultra-high vacuum electron beam evaporation or molecular beam epitaxy to evaporate a layer of low work function metal, and then remove the resist to form the drain electrode; Step 4: growing a gate oxide layer using atomic layer deposition; Step 5: Precisely overlay to form the gate electrode area, use an ultra-high vacuum electron beam evaporator to evaporate a layer of gate metal, and then remove the glue to form the gate electrode; or Step 1: Transfer or grow a single layer of two-dimensional semiconductor material on a substrate; Step 2: Form the source region by photolithography, use ultra-high vacuum electron beam evaporation to evaporate a layer of high work function metal, and form the source electrode after desmearing; Step 3: Precisely overlay to form the drain electrode area, using ultra-high vacuum electron beam evaporation or molecular beam epitaxy to evaporate a layer of low work function metal, and then remove the resist to form the drain electrode; Step 4: growing a gate oxide layer using atomic layer deposition; Step 5: Accurately overlay to form the gate electrode area, use an ultra-high vacuum electron beam evaporator to evaporate a layer of gate metal, and form the gate electrode after degumming.
10. The method for preparing a memristor transistor with asymmetric Schottky barrier modulation based on two-dimensional materials according to claim 9, characterized in that: In step 1, the substrate is ultrasonically cleaned with acetone, isopropyl alcohol, and deionized water in sequence, and then blown dry with a nitrogen gun.
11. Application of the asymmetric Schottky barrier modulated memristor based on two-dimensional materials according to any one of claims 1 to 10 in signal processing, high-resolution imaging, physical neural networks, neuromorphic computing, and in-memory computing.