CN108227243A - Automatically controlled THz wave regulation and control device of silicon substrate all dielectric type and preparation method thereof - Google Patents

Abstract

The invention provides a silicon-based all-dielectric electronically controlled terahertz wave control device and a preparation method thereof, including a double-layer cylindrical silicon micron structure, a high-resistance silicon substrate, doped silicon interdigitated electrodes, and a silicon dioxide nano-oxide layer And the vanadium dioxide film, the double-layer cylindrical silicon microstructure is located on the upper side of the high-resistance silicon substrate, the doped silicon interdigitated electrode, the silicon dioxide nano-oxide layer, and the vanadium dioxide film are located on the high-resistance silicon substrate from top to bottom. The underside of the substrate; the semiconductor high-resistance silicon material is selected as the main dielectric material in the present invention, which is easy to obtain, low in cost and mature in semiconductor processing technology; this device has very high terahertz wave transmittance and extremely low device insertion loss , and has a large working bandwidth; by introducing an oxide insulating layer between the vanadium dioxide film and the doped silicon interdigital electrode, the Joule heat generated by the current can be effectively suppressed, thereby increasing the switching speed of the device, which can be widely used in terahertz wave Detection, terahertz wave imaging and other fields.

Description

Silicon-based all-dielectric electrically controlled terahertz wave control device and preparation method thereof

technical field

The invention belongs to the technical field of terahertz wave applications, in particular to a silicon-based all-dielectric electrically controlled terahertz wave control device and a preparation method thereof.

Background technique

Terahertz wave (terahertz wave) is an electromagnetic wave spectrum whose waveband is between millimeter wave and infrared wave, its frequency is 0.1-10THz, and its wavelength is in the range of 30μm-3mm. It has unique electromagnetic properties and occupies an important position in the electromagnetic spectrum. In recent years, terahertz science and technology have developed rapidly, and have played a leading role in the fields of wireless communication, detection imaging, electronic countermeasures, security inspection, biomedical diagnosis and environmental monitoring, and have very important application value. has great significance. In these applications, terahertz imaging and communication technology has attracted more and more people's attention, and terahertz regulator is an indispensable key component in the system, and the quality of the control device directly affects the performance of the entire system Bad.

Silicon-based terahertz regulators have received extensive attention because they are compatible with existing semiconductor processes, such as literature: Wen T, Zhang D, Wen Q, et al. Enhanced Optical Modulation Depth of Terahertz Waves by Self‐Assembled Monolayer of Plasmonic Gold Nanoparticles[J].Advanced Optical Materials,2016,4. proposed a silicon-based optically controlled terahertz modulator, but in these devices, due to the high refractive index of the Si substrate, the device loss is very large, The insertion loss of the device is as high as 3-5dB, and due to the use of light control technology, it is not compatible with existing highly integrated electronic devices.

Vanadium dioxide (VO ₂ ) is a room temperature insulator-metal phase transition (MIT) material, which undergoes a transformation from an insulating phase to a metal phase driven by heat, light or an electric field, and its conductivity can generally range from 3 to 5 change in magnitude. In the insulator phase, vanadium dioxide has excellent transparency to terahertz waves, and the absorption and reflection losses are very small; while in the metal phase, vanadium dioxide can strongly reflect and partially absorb terahertz waves. Therefore, the amplitude regulation of terahertz waves can be achieved by using the phase transition of vanadium dioxide thin films. However, conventional thermal and optical actuation methods require additional thermal and optical devices, which cannot be integrated with current mainstream microelectronic systems. Although the electric drive method solves the compatibility problem of the electronic system, the metal electrode used has a strong reflection effect on the terahertz wave, which significantly increases the insertion loss of the device. More importantly, the use of conventional bias loading to drive the phase transition of _VO2 leads to a large accumulation of Joule heat in the vanadium dioxide material, which limits its regulation speed to less than 1 Hz due to the slow heat dissipation process. These factors limit the practical application of vanadium dioxide as an effective terahertz regulator.

Therefore, it is necessary to develop a terahertz wave control device that is compatible with semiconductor processes and existing highly integrated electronic systems, and has low insertion loss, large control depth, and high switching rate. The development of practical application systems such as existing terahertz imaging systems is of great value.

Contents of the invention

The object of the present invention is to provide a silicon-based all-dielectric electrically controlled terahertz wave control device and a preparation method thereof.

In order to realize the foregoing invention object, the technical scheme of the present invention is as follows:

A silicon-based all-dielectric electronically controlled terahertz wave control device, including a double-layer cylindrical silicon microstructure, a high-resistance silicon substrate, doped silicon interdigitated electrodes, a silicon dioxide nano-oxide layer and a vanadium dioxide film, wherein The double-layer cylindrical silicon microstructure is located on the upper side of the high-resistance silicon substrate, and the doped silicon interdigitated electrode, silicon dioxide nano-oxide layer, and vanadium dioxide film are located on the lower side of the high-resistance silicon substrate in sequence from top to bottom. The entire device does not contain metal materials and metal structures; the double-layer cylindrical silicon microstructure layer on the upper side of the high-resistance silicon substrate plays the role of terahertz wave anti-reflection, and the vanadium dioxide thin film structure layer on the lower side of the high-resistance silicon substrate acts To the regulation of the amplitude of terahertz waves.

As a preferred method, the double-layer cylindrical silicon microstructure, doped silicon interdigitated electrodes, and silicon dioxide nano-oxide layer in the entire device are all made of the same high-resistance silicon substrate through etching, doping, oxidation, and photolithography. Processed by standard semiconductor process.

As a preferred mode, the double-layer cylindrical silicon microstructure is a periodic array of silicon-based double-layer cylinders arranged in multiple rows and columns at equal intervals. The double-layer cylinders include an upper cylinder, a lower cylinder concentrically arranged below the upper cylinder, and an upper cylinder. The diameter of the cylinder is smaller than the diameter of the lower cylinder, the diameters of the two cylinders are all ≤ 100 microns, and the total height of the two cylinders is ≤ 100 microns.

As a preferred mode, the silicon-based double-layer cylindrical micron structure is directly processed from a high-resistance silicon substrate by semiconductor technology, and both belong to the same high-resistance silicon material.

As a preferred manner, the high-resistance silicon substrate is an intrinsic or high-resistance semiconductor Si material with a resistivity ≥ 3000Ω.cm and a thickness between 200 μm and 600 μm.

As a preferred mode, the doped silicon finger electrodes are formed by selectively doping the high-resistance silicon substrate, and its conductivity is adjusted by controlling the doping concentration. The width of the doped silicon finger electrodes is 3 μm Between -10μm and thickness between 50nm and 3μm.

As a preferred manner, the silicon dioxide nano-oxide layer is formed by oxidizing the high-resistance silicon substrate and doped silicon interdigital electrodes, and its thickness is between 50nm and 100nm.

As a preferred mode, the thickness of the vanadium dioxide film is 100nm-500nm, the change of resistivity before and after the phase transition reaches more than 3 orders of magnitude, and the square resistance of the film in the metal phase is ≤50Ω/Ω.

As a preferred method, the insertion loss of the device in the ultra-broadband terahertz frequency range exceeding 450 GHz is ≤1.5 dB, the control depth of the device reaches more than 76.5%, and the control speed is greater than 100 Hz.

In order to achieve the purpose of the above invention, the present invention also provides a method for preparing the above-mentioned silicon-based all-dielectric electrically controlled terahertz wave control device, which includes the following steps:

Step 1. Use the electromagnetic simulation software CST Microwave Studio to establish a 3D model of the silicon-based double-layer cylindrical microstructure unit. The total thickness of the model is 500 μm. After setting the boundary conditions and solver, optimize the radius r1 of the double-layer cylinder in the microstructure. r2, column height d1, d2, distance p between each double-layer column, to obtain maximum transmittance and working bandwidth;

Step 2. Clean the semiconductor silicon substrate: first put the silicon substrate into a beaker filled with acetone and ultrasonically clean it for 15 minutes, then use alcohol to ultrasonically clean it for 15 minutes, and finally use deionized water to ultrasonically clean it for 15 minutes. Blow dry with nitrogen, and dry in oven;

Step 3. After designing and processing the mask plate according to the designed microstructure size, first put the silicon substrate into a thermal oxidation furnace, and grow a 3μm thick silicon dioxide mask layer by dry oxygen oxidation method, and then use semiconductor photolithography to Process and ICP etching technology to process the silicon substrate, first make the bottom large-size cylinder, and then make the uppermost small-size cylinder to form a double-layer stepped cylinder microstructure;

Step 4. Preparation of doped silicon interdigitated electrodes: firstly, the SiO ₂ layer grown in the previous step is selected as the barrier layer for thermal diffusion doping, and secondly, the electromagnetic simulation software CST Microwave Studio is used for simulation to make the interdigitated electrodes transmit terahertz waves No effect, after optimization, the interdigital electrode lines and line gaps are both 7um, use photolithography technology to make interdigital electrode patterns on the barrier layer, and then dry etch the barrier layer to form interdigital electrode doping grooves; then use P is used as a thermal diffusion source; during the pre-diffusion experiment, under the nitrogen flow of 1L/min, the temperature in the furnace is raised to 850°C in 50 minutes, and the substrate is sent into the substrate at this temperature; it is raised to 1000°C in 15 minutes, Keep at ℃ for 40min, then cool down to 850℃ within 30min, take out the substrate, and finally use BOE water bath method to remove the remaining silicon dioxide barrier layer;

Step 5. Preparation of silicon dioxide insulating layer: dry oxygen oxidation method is adopted, and the density is better; the temperature in the furnace is raised to 850°C for 50 minutes under a nitrogen flow of 1L/min, and sent into the base at this temperature Continue to heat up, change to oxygen at this time, the flow rate is 1L/min, rise to 1000°C after 15min, and keep it for 30min; then start to cool down, let the temperature in the furnace drop to 850°C within 30min, take out the substrate, and prepare the The thickness of silicon dioxide is 50nm; this step is also the re-diffusion after pre-diffusion in the previous step, so that the performance of the doped silicon interdigitated electrode prepared in this way is better, and the measured electrode square resistance is 4Ω/Ω;

Step 6. Preparation of vanadium dioxide thin film: using radio frequency magnetron sputtering method, high-purity metal vanadium target is used in magnetron sputtering system parameters: radio frequency power 180w-220w, working pressure 1Pa, oxygen-argon flow ratio 4%-6 %, under the condition of a heating temperature of 550°C, deposit a 200nm vanadium dioxide film on the silicon dioxide insulating layer;

Step 7. Use the terahertz time-domain spectroscopy system THz-TDS to test the terahertz transmission performance of the device. The terahertz wave is incident on one side of the double-layer cylindrical microstructure, and the voltage applied to the device is provided by a constant voltage source. Connect to both ends of the interdigital electrodes, and record the THz-TDS system data immediately after the required voltage is applied.

The silicon-based double-layer cylindrical microstructure in the device is used to improve the control depth of the silicon-based vanadium dioxide type terahertz regulator and overcome the problem of large insertion loss of the original regulator substrate for terahertz waves. The core of the present invention is to use semiconductor high-resistance silicon material as the substrate, and use semiconductor photolithography and ICP etching technology to process the silicon substrate to form a surface microstructure that increases the transmission of terahertz waves, which can greatly improve the transmission of terahertz waves. The transmittance range is above 85% in a certain frequency range; at the same time, doped silicon interdigitated electrodes are fabricated on the other side of the substrate, and then an oxide insulating layer and a vanadium dioxide core control nanolayer are prepared. The all-dielectric device is used to solve the problem of being compatible with the existing microelectronic system, and at the same time suppress the problem of Joule heat generated by the device. The terahertz controller realized by the present invention has the advantages of low insertion loss, large working bandwidth, large regulation depth, and insensitivity to incident terahertz wave direction polarization, and can be widely used in terahertz imaging and detection systems.

In terms of working principle:

In the double-sided device proposed by the present invention, two functional layers are distributed on both sides of the high-resistance silicon substrate, one side plays the role of terahertz wave anti-reflection, and the other side plays the role of terahertz wave transmission regulation. A novel structure can simultaneously reduce device insertion loss and realize large-scale and rapid regulation. In the structure of the present invention, the high-resistance silicon material is selected as the substrate material because of its easy acquisition, low cost and mature semiconductor process characteristics. Etch the silicon surface into a specific three-dimensional structure, change the refractive index of the surface layer of the silicon substrate according to the equivalent refractive index model, and form a graded refractive index structure between the air and the silicon substrate to form an anti-reflection component, thereby increasing the transmission of terahertz waves At the same time, the control device of the present invention uses doped silicon interdigitated electrodes to load the voltage in order to be compatible with the microelectronic system process, and to reduce the terahertz wave loss caused by conventional metal electrodes; at the same time, an insulating layer with good compactness is selected to suppress the generation of Joule heat ; After the electrode of the device is loaded with a voltage, an electric field is generated to control the transition of the vanadium dioxide film from an insulating phase to a metal phase, and absorb the incident terahertz wave, thereby achieving the function of regulating the terahertz wave.

In sum, advantage and effect of the present invention have:

The invention provides a design theory and a preparation scheme of a silicon-based all-dielectric electronically controlled terahertz wave control device, which is based on the equivalent refractive index gradient anti-reflection theory. In the present invention, the semiconductor high-resistance silicon material is selected as the substrate, which is easy to obtain, low in cost, and the semiconductor processing technology is mature; moreover, the technology for preparing the vanadium dioxide thin film is relatively mature. Secondly, this device greatly improves the transmittance of terahertz waves, reduces insertion loss and has a large operating bandwidth; and the introduction of an oxide insulating layer between the vanadium dioxide film and the doped silicon interdigitated electrode can effectively suppress the current generation. Joule heat, and then improve the device control rate, to achieve the purpose of the present invention, can be widely used in terahertz wave communication systems, terahertz wave detection, terahertz wave imaging and other fields.

Description of drawings

Fig. 1 is a three-dimensional schematic diagram of the structure of the silicon-based all-dielectric electrically controlled terahertz wave regulating device of the present invention.

Fig. 2(a) is a simulation result diagram of a silicon-based double-layer cylindrical microstructure model and a bare silicon chip model of the present invention.

Fig. 2(b) is a diagram of experimental test results of a silicon-based double-layer cylindrical microstructure sample and a bare silicon chip of the present invention.

Fig. 3 (a) is the vanadium dioxide thin film test R-T thermal hysteresis loop that the present invention uses directly on the silicon dioxide insulating layer preparation

Fig. 3(b) is the XRD spectrum of the vanadium dioxide thin film prepared directly on the silicon dioxide insulating layer used in the present invention.

Fig. 4 is an actual test time-domain spectrum of the silicon-based all-dielectric electronically controlled terahertz wave control device of the present invention.

Fig. 5 is a fitting diagram of the actual test terahertz wave transmittance of the silicon-based all-dielectric electrically controlled terahertz wave control device of the present invention.

Fig. 6 is a fitting diagram of the actual test terahertz wave maximum control depth of the silicon-based all-dielectric electrically controlled terahertz wave control device of the present invention.

Among them, 1 is a double-layer cylindrical silicon microstructure, 2 is a high-resistance silicon substrate, 3 is a doped silicon interdigitated electrode, 4 is a silicon dioxide nano-oxide layer, 5 is a vanadium dioxide film, and 6 is an incident terahertz Wave.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

A silicon-based all-dielectric electronically controlled terahertz wave control device, including a double-layer cylindrical silicon microstructure 1, a high-resistance silicon substrate 2, a doped silicon interdigitated electrode 3, a silicon dioxide nano-oxide layer 4, and a silicon dioxide Vanadium thin film 5, wherein double-layer cylindrical silicon microstructure 1 is located on the upper side of high resistance silicon substrate 2, doped silicon interdigitated electrode 3, silicon dioxide nano-oxide layer 4, and vanadium dioxide thin film 5 are sequentially arranged from top to bottom Located on the lower side of the high-resistance silicon substrate 2, the entire device does not contain metal materials and metal structures; the double-layer cylindrical silicon microstructure layer on the upper side of the high-resistance silicon substrate 2 plays the role of terahertz wave anti-reflection, and the high-resistance silicon The structural layer of the vanadium dioxide thin film 5 on the underside of the substrate 2 plays a role in regulating the amplitude of the terahertz wave.

The double-layer cylindrical silicon microstructure 1, doped silicon interdigitated electrodes 3, and silicon dioxide nano-oxide layer 4 in the entire device are all made of the same high-resistance silicon substrate 2 through etching, doping, oxidation, and photolithography. Processed by standard semiconductor process.

The double-layer cylindrical silicon microstructure 1 is a periodic array of silicon-based double-layer cylinders arranged at equal intervals in multiple rows and columns. The double-layer cylinder includes an upper cylinder and a lower cylinder concentrically arranged below the upper cylinder. The diameter of the upper cylinder is less than The diameter of the lower cylinder, the diameters of the two layers of cylinders are all ≤ 100 microns, and the total height of the two layers of cylinders is ≤ 100 microns.

The silicon-based double-layer cylindrical microstructure 1 is directly processed from a high-resistance silicon substrate 2 by semiconductor technology, and both belong to the same high-resistance silicon material.

The high-resistance silicon substrate 2 is an intrinsic or high-resistance semiconductor Si material with a resistivity ≥ 3000Ω.cm and a thickness between 200 μm and 600 μm.

The doped silicon interdigital electrode 3 is formed by selectively doping the high-resistance silicon substrate 2, and its conductivity is adjusted by controlling the doping concentration. The width of the doped silicon interdigital electrode 3 is between 3 μm- Between 10μm and thickness between 50nm and 3μm. .

The silicon dioxide nano-oxide layer 4 is formed by oxidizing the high-resistance silicon substrate 2 and the doped silicon interdigital electrodes 3, and its thickness is between 50nm and 100nm.

The thickness of the vanadium dioxide thin film 5 is 100nm-500nm, the change of resistivity before and after the phase transition reaches more than 3 orders of magnitude, and the square resistance of the thin film in the metal phase is ≤50Ω/μm.

In the ultra-broadband terahertz frequency range exceeding 450GHz, the insertion loss of the device is ≤1.5dB, the control depth of the device reaches more than 76.5%, and the control speed is greater than 100Hz.

The preparation method of the above-mentioned silicon-based all-dielectric electrically controlled terahertz wave control device includes the following steps:

Step 1. Use the electromagnetic simulation software CST Microwave Studio to establish a 3D model of the silicon-based double-layer cylindrical microstructure unit. The total thickness of the model is 500 μm. After setting the boundary conditions and solver, optimize the radius r1 of the double-layer cylinder in the microstructure. r2, column height d1, d2, distance p between each double-layer column, to obtain maximum transmittance and working bandwidth;

Step 2. Clean the semiconductor silicon substrate: first put the silicon substrate into a beaker filled with acetone and ultrasonically clean it for 15 minutes, then use alcohol to ultrasonically clean it for 15 minutes, and finally use deionized water to ultrasonically clean it for 15 minutes. Blow dry with nitrogen, and dry in oven;

Step 3. After designing and processing the mask plate according to the designed microstructure size, first put the silicon substrate into a thermal oxidation furnace, and grow a 3μm thick silicon dioxide mask layer by dry oxygen oxidation method, and then use semiconductor photolithography to Process and ICP etching technology to process the silicon substrate, first make the bottom large-size cylinder, and then make the uppermost small-size cylinder to form a double-layer stepped cylinder microstructure;

Step 4. Preparation of doped silicon interdigitated electrodes: firstly, the SiO ₂ layer grown in the previous step is selected as the barrier layer for thermal diffusion doping, and secondly, the electromagnetic simulation software CST Microwave Studio is used for simulation to make the interdigitated electrodes transmit terahertz waves No effect, after optimization, the interdigital electrode lines and line gaps are both 7um, use photolithography technology to make interdigital electrode patterns on the barrier layer, and then dry etch the barrier layer to form interdigital electrode doping grooves; then use P is used as a thermal diffusion source; during the pre-diffusion experiment, under the nitrogen flow of 1L/min, the temperature in the furnace is raised to 850°C in 50 minutes, and the substrate is sent into the substrate at this temperature; it is raised to 1000°C in 15 minutes, Keep at ℃ for 40min, then cool down to 850℃ within 30min, take out the substrate, and finally use BOE water bath method to remove the remaining silicon dioxide barrier layer;

Step 5. Preparation of silicon dioxide insulating layer: dry oxygen oxidation method is adopted, and the density is better; the temperature in the furnace is raised to 850°C for 50 minutes under a nitrogen flow of 1L/min, and sent into the base at this temperature Continue to heat up, change to oxygen at this time, the flow rate is 1L/min, rise to 1000°C after 15min, and keep it for 30min; then start to cool down, let the temperature in the furnace drop to 850°C within 30min, take out the substrate, and prepare the The thickness of silicon dioxide is 50nm; this step is also the re-diffusion after pre-diffusion in the previous step, so that the performance of the doped silicon interdigitated electrode prepared in this way is better, and the measured electrode square resistance is 4Ω/Ω;

Step 6. Preparation of vanadium dioxide thin film: using radio frequency magnetron sputtering method, high-purity metal vanadium target is used in magnetron sputtering system parameters: radio frequency power 180w-220w, working pressure 1Pa, oxygen-argon flow ratio 4%-6 %, under the condition of a heating temperature of 550°C, deposit a 200nm vanadium dioxide film on the silicon dioxide insulating layer;

Step 7. Use the terahertz time-domain spectroscopy system THz-TDS to test the terahertz transmission performance of the device. The terahertz wave is incident on one side of the double-layer cylindrical microstructure, and the voltage applied to the device is provided by a constant voltage source. Connect to both ends of the interdigital electrodes, and record the THz-TDS system data immediately after the required voltage is applied.

The relevant test results are as follows:

Fig. 2 (b) is the actual test transmittance result figure of the silicon-based double-layer cylindrical microstructure designed in the specific embodiment of the present invention, it can be seen that the transmittance of this structure reaches more than 85% in a certain frequency band, compared with the same The parameter high-resistance bare silicon chip has increased by more than 15%. Compared with the simulation data in Figure 2(a), it can be seen that the design expectation has been achieved.

Fig. 3 is the square resistance change curve and XRD of the vanadium dioxide thin film prepared according to the specific embodiment of the present invention as the temperature changes, showing that the film undergoes a phase transition near 70°C, and the thin film square resistance changes more than 3 orders of magnitude; the XRD pattern shows The single crystal orientation of the thin film is good.

The THz-TDS time-domain spectrum 4 tested by the finished controller of the present invention is then processed to obtain the fitting diagram of the transmittance of the device in Figure 5 and the fitting diagram of the maximum control depth of the device in Figure 6 . From the analysis of the actual test results of the final product of the present invention, it can be seen that under the condition of no applied voltage, the vanadium dioxide film, the _SiO2 insulating layer and the fabricated doped silicon interdigitated electrodes have no insertion loss for the terahertz wave; As the applied voltage increases, the transmittance of the terahertz wave decreases continuously. When the voltage is increased to 3.5V, the vanadium dioxide film completely transforms from the insulating phase to the metal phase, and the transmittance of the device to the terahertz wave drops to about 20%. , it is calculated that the control depth of the whole device can reach more than 76.5%, indicating that the terahertz regulator provided by the present invention has low insertion loss and very high control depth.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims (10)

1. A silicon-based all-dielectric electronically controlled terahertz wave control device, characterized in that it includes a double-layer cylindrical silicon microstructure (1), a high-resistance silicon substrate (2), and doped silicon interdigitated electrodes (3 ), a silicon dioxide nano-oxide layer (4) and a vanadium dioxide film (5), wherein the double-layer cylindrical silicon microstructure (1) is located on the upper side of the high-resistance silicon substrate (2), and doped silicon interdigitated electrodes (3), silicon dioxide nano oxide layer (4), vanadium dioxide thin film (5) are located in the underside of high resistance silicon substrate (2) successively from top to bottom, and the whole device does not contain metal material and metal structure; The double-layer cylindrical silicon microstructure layer on the upper side of the resistive silicon substrate (2) plays the role of anti-reflection of terahertz waves, and the structural layer of vanadium dioxide film (5) on the lower side of the high-resistive silicon substrate (2) plays the role of antireflection. Terahertz wave amplitude regulation. 2. A kind of silicon-based all-dielectric type electronically controlled terahertz wave regulating device according to claim 1, characterized in that: the double-layer cylindrical silicon microstructure (1) in the whole device, doped silicon interdigitated electrodes ( 3) The silicon dioxide nano-oxide layer (4) is both processed from the same high-resistance silicon substrate (2) through standard semiconductor processes of etching, doping, oxidation, and photolithography. 3. A silicon-based all-dielectric electronically controlled terahertz wave control device according to claim 1, characterized in that: the double-layer cylindrical silicon microstructure (1) is arranged in multiple rows and columns with equal intervals A periodic array of silicon-based double-layer cylinders. The double-layer cylinders include the upper cylinder and the lower cylinder concentrically arranged under the upper cylinder. The diameter of the upper cylinder is smaller than the diameter of the lower cylinder. Height ≤ 100 microns. 4. A silicon-based all-dielectric type electronically controlled terahertz wave regulating device according to claim 1, characterized in that: the silicon-based double-layer cylindrical microstructure (1) is obtained from a high-resistance silicon substrate ( 2) It is processed directly on the surface, and both belong to the same high-resistance silicon material. 5. A silicon-based all-dielectric electronically controlled terahertz wave regulating device according to claim 1, characterized in that: the high-resistance silicon substrate (2) is an intrinsic or high-resistance semiconductor Si material, and its resistance Ratio ≥ 3000Ω.cm, thickness between 200μm ~ 600μm. 6. A silicon-based all-dielectric electronically controlled terahertz wave control device according to claim 1, characterized in that: the doped silicon interdigitated electrode (3) passes through the high-resistance silicon substrate (2) It is formed by selective doping, and its conductivity can be adjusted by controlling the doping concentration. The width of the doped silicon interdigital electrode (3) is between 3 μm and 10 μm, and the thickness is between 50 nm and 3 μm. 7. A silicon-based all-dielectric electronically controlled terahertz wave control device according to claim 1, characterized in that: the silicon dioxide nano-oxide layer (4) is formed by the high-resistance silicon substrate (2) And the doped silicon interdigitated electrode (3) is oxidized, and its thickness is between 50nm and 100nm. 8. A silicon-based all-dielectric electronically controlled terahertz wave regulating device according to claim 1, characterized in that: the thickness of the vanadium dioxide film (5) is 100nm-500nm, and the change in resistivity before and after the phase transition reaches More than 3 orders of magnitude, and the square resistance of the film in the metal phase is ≤50Ω/port. 9. A silicon-based all-dielectric electronically controlled terahertz wave control device according to claim 1, characterized in that: the insertion loss of the device in the ultra-wideband terahertz frequency range exceeding 450 GHz is ≤ 1.5 dB, and the control depth of the device is Reach more than 76.5%, the control speed is greater than 100Hz. 10. The method for preparing the silicon-based all-dielectric electrically controlled terahertz wave control device according to any one of claims 1 to 9, characterized in that it comprises the following steps: Step 1. Use the electromagnetic simulation software CST Microwave Studio to establish a 3D model of the silicon-based double-layer cylindrical microstructure unit. The total thickness of the model is 500 μm. After setting the boundary conditions and solver, optimize the radius r1 of the double-layer cylinder in the microstructure. r2, column height d1, d2, distance p between each double-layer column, to obtain maximum transmittance and working bandwidth; Step 2. Clean the semiconductor silicon substrate: first put the silicon substrate into a beaker filled with acetone and ultrasonically clean it for 15 minutes, then use alcohol to ultrasonically clean it for 15 minutes, and finally use deionized water to ultrasonically clean it for 15 minutes. Blow dry with nitrogen, and dry in oven; Step 3. After designing and processing the mask plate according to the designed microstructure size, first put the silicon substrate into a thermal oxidation furnace, and grow a 3μm thick silicon dioxide mask layer by dry oxygen oxidation method, and then use semiconductor photolithography to Process and ICP etching technology to process the silicon substrate, first make the bottom large-size cylinder, and then make the uppermost small-size cylinder to form a double-layer stepped cylinder microstructure; Step 4. Preparation of doped silicon interdigitated electrodes: firstly, the SiO ₂ layer grown in the previous step is selected as the barrier layer for thermal diffusion doping, and secondly, the electromagnetic simulation software CST Microwave Studio is used for simulation to make the interdigitated electrodes transmit terahertz waves No effect, after optimization, the interdigital electrode lines and line gaps are both 7um, use photolithography technology to make interdigital electrode patterns on the barrier layer, and then dry etch the barrier layer to form interdigital electrode doping grooves; then use P is used as a thermal diffusion source; during the pre-diffusion experiment, under the nitrogen flow of 1L/min, the temperature in the furnace is raised to 850°C in 50 minutes, and the substrate is sent into the substrate at this temperature; it is raised to 1000°C in 15 minutes, Keep at ℃ for 40min, then cool down to 850℃ within 30min, take out the substrate, and finally use BOE water bath method to remove the remaining silicon dioxide barrier layer; Step 5. Preparation of silicon dioxide insulating layer: dry oxygen oxidation method is adopted, and the density is better; the temperature in the furnace is raised to 850°C for 50 minutes under a nitrogen flow of 1L/min, and sent into the base at this temperature Continue to heat up, change to oxygen at this time, the flow rate is 1L/min, rise to 1000°C after 15min, and keep it for 30min; then start to cool down, let the temperature in the furnace drop to 850°C within 30min, take out the substrate, and prepare the The thickness of silicon dioxide is 50nm; this step is also the re-diffusion after pre-diffusion in the previous step, so that the performance of the doped silicon interdigitated electrode prepared in this way is better, and the measured electrode square resistance is 4Ω/Ω; Step 6. Preparation of vanadium dioxide thin film: using radio frequency magnetron sputtering method, high-purity metal vanadium target is used in magnetron sputtering system parameters: radio frequency power 180w-220w, working pressure 1Pa, oxygen-argon flow ratio 4%-6 %, under the condition of a heating temperature of 550°C, deposit a 200nm vanadium dioxide film on the silicon dioxide insulating layer; Step 7. Use the terahertz time-domain spectroscopy system THz-TDS to test the terahertz transmission performance of the device. The terahertz wave is incident on one side of the double-layer cylindrical microstructure, and the voltage applied to the device is provided by a constant voltage source. Connect to both ends of the interdigital electrodes, and record the THz-TDS system data immediately after the required voltage is applied.