A mesfet device based on flexoelectric effect and photoelectric effect enhancement

Abstract

The application discloses a MESFET device based on flexoelectric effect and photoelectric effect enhancement, which comprises a laser light source, a silicon substrate, an insulating layer, a metal gate electrode, a two-dimensional semiconductor layer, a first source-drain electrode and a second source-drain electrode. The insulating layer is arranged on the silicon substrate; the metal gate electrode and the two-dimensional semiconductor layer are arranged on the insulating layer, and the two-dimensional semiconductor layer covers the metal gate electrode. The first source-drain electrode and the second source-drain electrode are arranged on the two-dimensional semiconductor layer and are located on opposite sides of the metal gate electrode respectively. The laser light source is directed towards the two-dimensional semiconductor layer. The first source-drain electrode and the second source-drain electrode each comprise an electrode main body. A plurality of pressing needle tips are arranged on the electrode main body of the first source-drain electrode and / or the second source-drain electrode. The tips of the pressing needle tips are directed towards the two-dimensional semiconductor layer. Under the action of the flexoelectric field, the source-drain current of the MESFET device is more easily saturated, and the driving capacity of the source-drain current of the MESFET device is increased.

Description

Technical Field

[0001] This invention relates to the field of semiconductor electronic components, and more specifically to a two-dimensional semiconductor MESFET device based on enhanced flexural and photoelectric effects. Background Technology

[0002] A field-effect transistor (FET) is a semiconductor device that uses an electric field effect to control the output current. FETs have wide applications in integrated circuits, playing a particularly important role in novel electronic devices. These novel electronic devices mainly include: fitness trackers, flexible electronic screens, biosensors, thin-film technology, and flexible electrochemical energy storage devices. However, the opaque and inflexible nature of traditional silicon semiconductors limits their application in these fields. Molybdenum disulfide (MoS2), as a typical transition metal sulfide, combines the properties of a semiconductor with those of a two-dimensional material. Monolayer molybdenum disulfide is a direct bandgap semiconductor with a bandgap of 1.90 eV. As the number of layers increases, the direct bandgap transforms into an indirect bandgap, with bulk molybdenum disulfide having a bandgap of 1.29 eV. Furthermore, two-dimensional molybdenum disulfide materials possess atomic-level thickness and exhibit flexibility and light transmittance. Bilayer molybdenum disulfide (MoDS) exhibits superior properties compared to monolayer MoDS (such as higher carrier mobility and driving current), and also possesses unique physical properties not found in monolayer structures—the Giant Stark effect and interlayer excitons. These unique electrical and physical properties make MoDS an ideal material for fabricating high-performance electronic and optoelectronic devices. In particular, a major advantage of two-dimensional materials is the absence of dangling bonds on their surface, thus minimizing carrier scattering, which is impossible in traditional bulk semiconductors.

[0003] Two-dimensional materials, due to their nanoscale thickness, exhibit significant size effects. The flexural electrical effect can induce substantial electromechanical coupling in these materials. The flexural electrical effect is an electromechanical coupling phenomenon describing the interaction between polarization and strain gradients or non-uniform strain. Unlike the piezoelectric effect, the flexural electrical effect exists in all dielectric materials. The flexural electrical effect is divided into positive flexural electrical effect, i.e., polarization caused by strain gradients or non-uniform strain, and inverse flexural electrical effect, i.e., stress caused by electric field gradients or non-uniform electric fields. This invention relates to the positive flexural electrical effect, described as: flexural polarization intensity P i =f ijkl S jk，l f ijkl S is a coefficient describing the magnitude of the flexural electrical effect. jk，lIt refers to the strain gradient of the material. Through appropriate loading methods and geometric design, the strain gradient of a material can be made very large, allowing dielectric materials to obtain a sufficiently large flexural electric field. The flexural effect, as a novel research hotspot in the field of smart materials and structures, has great potential in sensing, actuation, and new energy fields.

[0004] A metal-semiconductor field-effect transistor (MESFET) is structurally similar to a junction field-effect transistor (JFET), but instead of using a PN junction as its gate, it employs a Schottky junction formed by the contact between a metal and a semiconductor to create the gate for gate control. MESFETs are typically made of compound semiconductors and operate faster than silicon-based JFETs or MOSFETs. MESFETs generally operate at high frequencies, up to 45 GHz, and are widely used in microwave communication, radar, and other equipment. MESFET devices have a simple structure and are easy to manufacture.

[0005] MESFET devices primarily consist of three electrodes: source, drain, and gate. The source-drain voltage-current characteristics are altered by controlling the voltage at the gate. Applying a gate voltage is a traditional method for controlling the depletion layer width at the MESFET gate. However, applying mechanical force to the semiconductor near the gate achieves the same effect of gate voltage control. The flexural effect significantly enhances MESFET performance. The flexural effect converts mechanical energy applied to the semiconductor into a flexural polarization electric field. The presence of this field improves MESFET device performance, such as carrier mobility. Studies have shown that, using traditional gate control methods, MESFET devices fabricated with 34nm MoS2 and MoOx / Au contacts achieve an electron mobility of 160 cm⁻¹. -2 / (V·s). In traditional MESFET devices, the opaque metal electrode at the gate is covered by the semiconductor surface, causing a significant portion of the semiconductor to lose its photoelectric effect (the phenomenon of converting light energy into electrical energy). Therefore, to improve the photoelectric effect performance of MESFET devices, structural innovations are needed to increase the area of ​​the semiconductor exposed to light, thus enhancing the photoelectric effect. With the enhancement of both flexural and photoelectric effects, the performance of MESFET devices can be further improved. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of low gate voltage control efficiency, inconvenient voltage-controlled gate depletion layer width, small source-drain current output, low carrier mobility, and low photoelectric conversion efficiency of traditional MESFET devices, and to provide a two-dimensional semiconductor MESFET device based on flexural effect and photoelectric effect enhancement.

[0007] In a first aspect, the present invention provides a MESFET device enhanced by flexural and photoelectric effects, comprising a laser source, a silicon substrate, an insulating layer, a metal gate electrode, a two-dimensional semiconductor layer, a first source / drain electrode, and a second source / drain electrode. The insulating layer is disposed on the silicon substrate; the metal gate electrode and the two-dimensional semiconductor layer are disposed on the insulating layer, and the two-dimensional semiconductor layer covers the metal gate electrode. The first source / drain electrode and the second source / drain electrode are disposed on the two-dimensional semiconductor layer and are located on opposite sides of the metal gate electrode. The laser source faces the two-dimensional semiconductor layer.

[0008] Both the first and second source / drain electrodes include an electrode body. Multiple pressure-down tips are disposed on the electrode bodies of the first and / or second source / drain electrodes. The tips of the pressure-down tips face the two-dimensional semiconductor layer.

[0009] Preferably, the laser light source is used to irradiate the area on the metal gate electrode covered by a two-dimensional semiconductor layer.

[0010] Preferably, the two-dimensional semiconductor layer comprises n molybdenum disulfide layers stacked together; 2≤n≤10.

[0011] Preferably, the output wavelength of the laser light source is 500nm to 900nm, and the output power is 1mW to 2mW.

[0012] Preferably, the insulating layer is made of silicon dioxide. The metal gate electrode is disposed in the middle of the side of the insulating layer facing away from the silicon substrate.

[0013] Preferably, the pressure needles are arranged in a matrix.

[0014] Preferably, the pressing needle tip is conical, and the tip has a rounded corner with a radius of r, where r is between 1 nm and 100 nm.

[0015] Preferably, a first source / drain electrode and / or a second source / drain electrode with a pressing tip are provided to apply a pressing force F to the two-dimensional semiconductor layer; the pressing force F is 10nN to 100μN.

[0016] Preferably, the metal gate electrode is made of Pt or a metal with a work function greater than Pt.

[0017] Secondly, the present invention provides a method for fabricating the aforementioned MESFET device, which includes the following steps:

[0018] Step 1: A layer of silicon dioxide is generated on the silicon substrate by thermal oxidation as an insulating layer; a metal gate electrode is generated on the insulating layer by electron beam evaporation deposition of a metal film.

[0019] Step 2: Transfer n single-layer molybdenum disulfide semiconductors sequentially onto a silicon dioxide insulating layer to form a two-dimensional semiconductor layer covering the metal gate electrode.

[0020] Step 3: Install the first source / drain electrode and the second source / drain electrode at both ends of the two-dimensional semiconductor layer, respectively.

[0021] Step 4: Perform vacuum annealing on the device obtained in Step 3.

[0022] Thirdly, the present invention provides an application of the aforementioned MESFET device enhanced by flexural and photoelectric effects as a micro force measurement device; in this application, a first or second source-drain electrode of the pressure needle tip is provided as the detection area of ​​the micro force measurement device.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. This invention provides a pressure-down needle tip on the source and drain electrodes, which applies a compressive force to the two-dimensional semiconductor layer, forming a flexural electric field. Under the action of the flexural electric field, the source and drain currents of the MESFET device are more likely to reach saturation, thereby reducing the gate voltage required for the MESFET device to operate and increasing the driving capability of the source and drain currents of the MESFET device.

[0025] 2. The present invention applies laser irradiation to the two-dimensional semiconductor layer, applies voltage to the gate, and induces a flexural electric field at the source and drain electrodes using a pressure needle tip. Under the combined effect of these three factors, the current conducting at the source and drain electrodes is significantly enhanced, thereby greatly improving the carrier mobility of the MESFET device.

[0026] 3. The minute extrusion pressure change of the pressure needle tip on the source and drain electrodes of the present invention can significantly change the electrical parameters of the MESFET device; therefore, the MESFET device provided by the present invention can be used as a high-precision micro-force measurement sensor. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the MESFET device provided in Embodiment 1 of the present invention.

[0028] Figure 2 This is a side view of the first source / drain electrode or the second source / drain electrode in Embodiment 1 of the present invention.

[0029] Figure 3 This is a three-dimensional schematic diagram of the first source / drain electrode or the second source / drain electrode in Embodiment 1 of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of the pressing needle tip in Embodiment 1 of the present invention.

[0031] Figure 5This is a source-drain voltage-current relationship diagram of the MESFET device provided in Embodiment 1 of the present invention when the extrusion pressure is 0.

[0032] Figure 6 This is the source-drain voltage-current relationship diagram of the MESFET device provided in Embodiment 1 of the present invention when the extrusion pressure is 287.37nN.

[0033] Figure 7 This is the source-drain voltage-current relationship diagram of the MESFET device provided in Embodiment 1 of the present invention when the extrusion pressure is 1149.50nN.

[0034] Figure 8 This is a source-drain voltage-current relationship diagram of the MESFET device provided in Embodiment 2 of the present invention under different extrusion forces in the light and dark states.

[0035] In the figure: 1. Silicon substrate; 2. Insulating layer; 3. First source / drain electrode; 3.1. Pressing tip; 4. Second source / drain electrode; 5. Metal gate electrode; 6. Two-dimensional semiconductor layer. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] Example 1

[0038] like Figure 1 As shown, a MESFET device enhanced by flexural and photoelectric effects includes a laser source, a silicon substrate 1, an insulating layer 2 on the silicon substrate 1, a metal gate electrode 5 on the insulating layer 2, a two-dimensional semiconductor layer 6, and a first source / drain electrode 3 and a second source / drain electrode 4 on the two-dimensional semiconductor layer 6. The two-dimensional semiconductor layer 6 comprises two stacked monolayer molybdenum disulfide layers. The output port of the laser source faces the region on the two-dimensional semiconductor layer 6 corresponding to the metal gate electrode 5. The output wavelength of the laser source is 860 nm, and the output power is 1 mW.

[0039] The insulating layer 2 is made of silicon dioxide. The metal gate electrode 5 is disposed in the middle of the side of the insulating layer 2 facing away from the silicon substrate 1; the two-dimensional semiconductor layer 6 covers the outside of the metal gate electrode 5. The first source / drain electrode 3 and the second source / drain electrode 4 are respectively disposed on opposite sides of the metal gate electrode 5.

[0040] like Figure 1As shown in Figures 2, 3, and 4, the first source / drain electrode 3 and the second source / drain electrode 4 have the same structure, both including a sheet-like electrode body and a plurality of pressing tips 3.1 uniformly arranged in a 10×10 array on the side of the electrode body facing the insulating layer 2. The pressing tips 3.1 are conical in shape, with a rounded corner of radius r at the tip; in this embodiment, r ranges from 1 nm to 100 nm, preferably 20 nm. The tips of each pressing tip 3.1 are pressed against the two-dimensional semiconductor layer 6, applying a preload force to the two-dimensional semiconductor layer 6, so that the first source / drain electrode 3 and the second source / drain electrode 4 apply a continuous pressing force to the two-dimensional semiconductor layer 6. The pressing force can be provided by a mass block on the first source / drain electrode 3 and the second source / drain electrode 4, or by a pressing mechanism mounted on the base. The pressing mechanism can adjust the continuous pressing force applied by the first source / drain electrode 3 and the second source / drain electrode 4 to the two-dimensional semiconductor layer 6. The pressing tips 3.1 serve both as electrodes in contact with molybdenum disulfide and as tools for applying force. The electrode body is made of Au; the pressure needle tip 3.1 is made of Ag.

[0041] In this embodiment, the two-dimensional semiconductor layer 6 is made of double-layer molybdenum disulfide. The two-dimensional semiconductor layer 6 is rectangular with a length of 20 μm and a width of 10 μm; the metal gate electrode 5 is made of Pt, with an arbitrary length and a width of 10 μm; the first source / drain electrode 3 and the second source / drain electrode 4 have arbitrary lengths and a width of 20 μm.

[0042] This embodiment provides a non-essential preferred technical solution: the two-dimensional semiconductor layer 6 has a regular shape, such as a rectangle.

[0043] This embodiment provides a non-essential preferred technical solution: the width of the two-dimensional semiconductor layer 6 is 10nm-20μm.

[0044] This embodiment provides a non-essential preferred technical solution: the width of the metal gate electrode should not be too long or too short. If it is too long, the depletion layer formed at the gate will be too long, resulting in restricted carrier flow at the source and drain; if it is too short, the depletion layer formed at the gate will be too weak, and the gate's role in controlling the source and drain voltage and current characteristics of the MESFET device will not be fully realized. In this embodiment, the width of the metal gate electrode is set to 10nm-20μm.

[0045] This embodiment provides a non-essential preferred technical solution: the distance between the metal gate electrode 5 and the first source / drain electrode 3 is 10nm-20μm. The distance between the metal gate electrode 5 and the second source / drain electrode 4 is 10nm-20μm.

[0046] This embodiment provides a non-essential preferred technical solution: the tip of the pressing needle is a spherical indenter.

[0047] This embodiment provides a non-essential preferred technical solution: the radius of the spherical indenter at the tip of the pressure needle is 1nm-100nm. The smaller the tip radius, the greater the strain gradient on the two-dimensional semiconductor material due to the size effect, resulting in a greater flexural polarization intensity. Due to the influence of the flexural effect, the source-drain current of the MESFET device rises faster with the source-drain voltage.

[0048] This embodiment provides a non-essential preferred technical solution: the extrusion force applied to the two-dimensional semiconductor layer 6 by the first source / drain electrode 3 and the second source / drain electrode 4 is 10nN-100μN. The greater the downward pressure, the greater the strain gradient, and the greater the flexural polarization intensity. The source / drain current of the MESFET device rises faster with the source / drain voltage.

[0049] For the MESFET device provided in Example 1, the compressive force of the first source / drain electrode 3 and the second source / drain electrode 4 on the two-dimensional semiconductor layer 6 is set to 0. Under optical conditions (laser source on), voltages of -2V, -1V, 0V, 1V, 3V, and 5V are applied to the metal gate electrode 5, respectively, and the voltage-current relationship between the first source / drain electrode 3 and the second source / drain electrode 4 is measured as follows: Figure 5 As shown. From Figure 5 As can be seen from this, the gate voltage V GS The larger the value, the greater the source-drain voltage V. DS The source-drain current increases, but the increase is not significant. When the source-drain voltage is applied up to a maximum of 2V, the carrier mobility is 0.8cm². -2 / (V·s) has clearly not yet reached its maximum value, indicating that the driving capability of the MESFET device provided in Example 1 under only optical conditions is relatively weak.

[0050] Example 2

[0051] A MESFET device enhanced by flexural and photoelectric effects. The difference between this embodiment and embodiment 1 is that neither the first source / drain electrode 3 nor the second source / drain electrode 4 has a pressure tip 3.1. The rest of the structure is the same as that of embodiment 1.

[0052] Regarding the MESFET device provided in Example 2. For example... Figure 8 As shown, under light conditions, the MESFET device begins to exhibit significant source-drain current when the source-drain voltage reaches 0.5V, and the voltage-current relationship between the source and drain electrodes changes significantly with the pressure of the probe tip. Under dark conditions, the MESFET device only begins to exhibit significant source-drain current when the source-drain voltage reaches 1.5V, and the voltage-current relationship between the source and drain electrodes does not change significantly with the pressure of the probe tip. Figure 8It can be seen that the MESFET device provided in Example 2 has good force sensing performance under illumination conditions, which proves the role of photoelectric effect in improving the performance of MESFET device. The principle is that the photoelectric effect occurs in the double-layer molybdenum disulfide semiconductor under light, which makes it easier for charge carriers in the device to pass through the channel, thereby turning on the device.

[0053] For the MESFET device provided in Example 2, the compressive force of the first source / drain electrode 3 and the second source / drain electrode 4 on the two-dimensional semiconductor layer 6 is set to 287.37 nN. Under optical conditions, voltages of 0V, 4V, and 5V are applied to the metal gate electrode 5, and the voltage-current relationship between the first source / drain electrode 3 and the second source / drain electrode 4 is measured as follows: Figure 6 As shown. From Figure 6 As can be seen, taking a source-drain voltage of 1V as an example, a source-drain current of 2nA is achieved only with a gate voltage of about 4V; and as the source-drain voltage continues to increase, the source-drain current also increases rapidly.

[0054] For the MESFET device provided in Example 2, the compressive force of the first source / drain electrode 3 and the second source / drain electrode 4 on the two-dimensional semiconductor layer 6 is set to 1149.50 nN. Under optical conditions, voltages of 0V, 2V, and 3V are applied to the metal gate electrode 5, and the voltage-current relationship between the first source / drain electrode 3 and the second source / drain electrode 4 is measured as follows: Figure 7 As shown. From Figure 7 As can be seen, taking a source-drain voltage of 1V as an example, a gate voltage of about 2V is only required to achieve a source-drain current of 2nA. This indicates that as the compressive force increases and the flexural electric field continues to increase, the gate voltage required for the same source-drain voltage and current is smaller, meaning that the required turn-on gate voltage for the device is also smaller.

[0055] Combination Figure 6 and 7 It can be seen that under optical conditions, the larger the flexural electric field, the smaller the turn-on voltage required for the MESFET device provided in Example 1, and the easier it is to switch the MESFET device. Furthermore, as the pressure from the needle tip increases, the strain gradient of the semiconductor increases, resulting in an enhanced flexural polarization electric field, which increases the source-drain current at the same source-drain voltage. Taking the source-drain voltage V... Ds For example, when a force of 1149.50 nN is applied to the Ag / Au source or drain electrode with a pressure-down needle tip, the gate voltage V is... Gs With a gate voltage of 2V, the source-drain current can reach over 2nA; however, without additional tip pressure, the MESFET device provided in Example 1 requires a gate voltage of over 5V to achieve a source-drain current of 2nA. With a source-drain voltage of 2V, a gate voltage of 2V, and a tip pressure of 1436.87nN, the carrier mobility of the MESFET device provided in Example 2 is 470cm⁻¹. -2 / (V·s), but has not yet reached saturation. This demonstrates the significant advantages of MESFET devices with enhanced flexural conductivity mechanisms. Furthermore, it can be seen that the MESFET device provided in Example 2 exhibits source-drain voltage-current relationships corresponding to different forces, making it suitable as a miniature force measurement device.

[0056] Example 3

[0057] A MESFET device enhanced by flexural and photoelectric effects. The difference between this embodiment and Embodiment 1 is that the number of molybdenum disulfide layers in the two-dimensional semiconductor layer 6 is greater than 2 and less than or equal to 10, which is n layers.

[0058] Example 4

[0059] A MESFET device enhanced by flexural and photoelectric effects is presented in this embodiment, which differs from Embodiment 1 in that the metal gate electrode 5 is made of a metal material with a work function greater than Pt. Theoretically, the larger the work function of the electrode at the gate, the better the Schottky rectifier junction is formed, and the better the gate switching effect of the MESFET device.

[0060] Example 5

[0061] A method for fabricating a MESFET device enhanced by flexural and photoelectric effects includes the following steps:

[0062] Step 1: A layer of silicon dioxide is generated on the silicon substrate 1 by thermal oxidation to serve as the insulating layer 2. A metal gate electrode 5 is generated on the insulating layer 2 by electron beam evaporation deposition of a metal film.

[0063] Step 2: Two monolayer molybdenum disulfide semiconductors are sequentially transferred onto a silicon dioxide insulating layer to form a two-dimensional semiconductor layer 6 covering the metal gate electrode 5. Due to the large difference in work function between the metal gate electrode 5 and the two-dimensional semiconductor layer 6, a good Schottky junction is formed between them. The two-dimensional semiconductor layer 6 covering the metal gate electrode 5 increases the exposed semiconductor area, which helps to increase the photoelectric conversion efficiency. Furthermore, since this two-dimensional semiconductor layer 6 (i.e., the double-layer molybdenum disulfide) has no in-plane or out-of-plane piezoelectric effects, the influence of piezoelectric effects on the performance improvement of the MESFET device can be eliminated, which fully demonstrates the significant influence of flexural effects on MESFET devices.

[0064] Step 3: Install Ag / Au electrodes with pressure-down tips at both ends of the two-dimensional semiconductor layer 6 to form the first source / drain electrode 3 and the second source / drain electrode 4. By controlling the pressure applied to the two-dimensional semiconductor layer 6 by the pressure-down tip 3.1, the magnitude of the generated flexural electric field can be controlled. The pressure-down tip 3.1 on the Ag / Au electrode is made of Ag, and the rest is made of Au. Because the work function difference between Ag and the two-dimensional semiconductor layer 6 is small, it is not easy to form a Schottky rectifier junction after contact. The ohmic contact at the source / drain electrode helps to reduce the loss of source / drain voltage and current. The remaining source / drain electrode parts are made of Au because Au electrodes have good conductivity. As part of an integrated circuit, the MESFET device should have the characteristic of good electrode conductivity.

[0065] Step 4: In order to eliminate the gaps between the two monolayer molybdenum disulfide semiconductors in the two-dimensional semiconductor layer 6, between the two-dimensional semiconductor layer 6 and the metal gate electrode 5, and between the two-dimensional semiconductor layer 6 and the silicon substrate 1, the device obtained in Step 3 is vacuum annealed at 200°C for 30 minutes.

[0066] Step 5: Package the device obtained in Step 4 using a press-fit packaging method.

[0067] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A MESFET device based on flexural and photoelectric effects, comprising a laser source, a silicon substrate (1), an insulating layer (2), a metal gate electrode (5), a two-dimensional semiconductor layer (6), a first source / drain electrode (3), and a second source / drain electrode (4); characterized in that: An insulating layer (2) is disposed on a silicon substrate (1); a metal gate electrode (5) and a two-dimensional semiconductor layer (6) are disposed on the insulating layer (2), and the two-dimensional semiconductor layer (6) covers the metal gate electrode (5); a first source / drain electrode (3) and a second source / drain electrode (4) are disposed on the two-dimensional semiconductor layer (6), and are located on opposite sides of the metal gate electrode (5); the laser source faces the two-dimensional semiconductor layer (6). The first source / drain electrode (3) and the second source / drain electrode (4) both include an electrode body; the electrode bodies of the first source / drain electrode (3) and / or the second source / drain electrode (4) are provided with a plurality of pressing tips (3.1); the tips of the pressing tips (3.1) face the two-dimensional semiconductor layer (6).

2. The MESFET device based on flexural and photoelectric effects enhancement according to claim 1, characterized in that: The two-dimensional semiconductor layer (6) comprises n molybdenum disulfide layers stacked together; 2≤n≤10.

3. The MESFET device based on flexural and photoelectric effects enhancement according to claim 1, characterized in that: The laser light source has an output wavelength of 500nm to 900nm and an output power of 1mW to 2mW.

4. The MESFET device based on flexural and photoelectric effects enhancement according to claim 1, characterized in that: The insulating layer (2) is made of silicon dioxide; the metal gate electrode (5) is disposed in the middle of the side of the insulating layer (2) away from the silicon substrate (1); the irradiation position of the laser source is the area on the metal gate electrode (5) covered by the two-dimensional semiconductor layer (6).

5. A MESFET device based on flexural and photoelectric effects enhancement according to claim 1, characterized in that: Each pressing needle tip (3.1) is arranged in a matrix.

6. A MESFET device based on flexural and photoelectric effects enhancement according to claim 1, characterized in that: The pressing needle tip (3.1) is conical, and the tip has a rounded corner with a radius of r; the value of r is 1nm to 100nm.

7. A MESFET device based on flexural and photoelectric effects enhancement according to claim 1, characterized in that: The first source / drain electrode (3) and / or the second source / drain electrode (4) with a pressing tip (3.1) apply a pressing force F to the two-dimensional semiconductor layer (6); the pressing force F is 10nN to 100µN.

8. A MESFET device based on flexural and photoelectric effects enhancement according to claim 1, characterized in that: The metal gate electrode (5) is made of Pt or a metal with a work function greater than Pt.

9. The method for fabricating a MESFET device based on flexural and photoelectric effects as described in claim 1, characterized in that: Includes the following steps: Step 1: A layer of silicon dioxide is generated on the silicon substrate (1) by thermal oxidation as an insulating layer (2); a metal gate electrode (5) is generated on the insulating layer (2) by electron beam evaporation deposition of a metal film. Step 2: Transfer two monolayer molybdenum disulfide semiconductors sequentially onto the silicon dioxide insulating layer to form a two-dimensional semiconductor layer (6) covering the metal gate electrode (5). Step 3: Install the first source / drain electrode (3) and the second source / drain electrode (4) at both ends of the two-dimensional semiconductor layer (6); Step 4: Perform vacuum annealing on the device obtained in Step 3.

10. The application of the MESFET device based on flexural and photoelectric effects as described in claim 1 as a miniature force measurement device; characterized in that: The device is equipped with a pressure needle tip (3.1), a first source / drain electrode (3), or a second source / drain electrode (4) as the detection area of ​​the micro force measurement device.

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