Method for quantitative regulation of multiphase vanadium oxide and application of multiphase vanadium oxide

Abstract

The present application relates to a kind of quantitative regulation method of multiphase vanadium oxide and the application of multiphase vanadium oxide, belong to laser application technical field.The purpose of the present application is to solve the problems such as low thermal sensitivity of existing temperature measuring device, miniaturization is difficult, application is limited greatly, provide a kind of quantitative regulation method of multiphase vanadium oxide and the application of multiphase vanadium oxide;The temperature measuring device is based on femtosecond laser direct writing technology processing, without mask, can flexibly realize the characteristic regulation of thermosensitive material, high-precision microstructured preparation etc..Meanwhile, the temperature measuring device has high performance (high TCR, low noise) and high response speed, has microscale thin film design (can maximize the specific surface area of device), can be applied to calorimetric ionizing radiation dosimetry, microbolometer etc. technical field.

Description

TECHNICAL FIELD

[0001] The application relates to a method for quantitatively regulating multiphase vanadium oxide and application of the multiphase vanadium oxide and belongs to the technical field of laser application. BACKGROUND

[0002] Temperature sensors realize temperature detection by sensing temperature changes and converting them into available output signals. Thermal sensitive temperature measuring devices are one of the most widely used temperature sensors and have been widely applied to various fields such as aerospace, industrial manufacturing, medical health, metrology science and the like. With the progress and development of science and technology, the performance and design requirements of the temperature measuring devices are increasingly high, and microscale low disturbance, high performance (μK measurement level, low noise) and high response speed need to be considered. Conventional thermal sensitive temperature measuring devices based on metal Pt, Ni and the like and having a bulk design have faced severe challenges.

[0003] Vanadium oxide is a new type of thin film thermal sensitive material, has a high temperature coefficient of resistance (TCR), a low sheet resistance and a low noise coefficient, has been reported to be used for application researches such as calorimetric ionizing radiation dosimetry and microbolometer, and provides an advantageous material for the preparation of high-performance and miniaturized temperature measuring devices. Vanadium oxides have various phase forms (such as vanadium dioxide (VO2), divanadium trioxide (V2O3), divanadium pentoxide (V2O5) and the like), however, although single phases such as VO2 / V2O5 both have a high TCR, VO2 has a significant temperature hysteresis effect, and V2O5 has a too large resistivity at room temperature; V2O3 has a small resistivity at room temperature, but its TCR is low. Researches show that vanadium oxide films with high TCR and low sheet resistance are generally multiphase vanadium oxides composed of proper proportions of VO2, V2O3, V2O5 and the like, and therefore it is crucial to explore a flexible and controllable regulation method of the multiphase vanadium oxide and a high-efficiency and high-precision preparation technology of a multiphase vanadium oxide thin film microstructured thermal sensitive unit. Traditional methods such as high-temperature annealing and ion doping can be used for phase regulation of vanadium oxides, but the above methods are difficult to regulate and control the formation of multiphase vanadium oxide with specific proportions, and the preparation process is complex. Femtosecond laser is a pulsed laser with a pulse width in the order of femtosecond (1 fs = 10 -15 s), has the advantages of short irradiation period, high intensity and small thermal influence area, can flexibly realize controllable regulation of material physical and chemical properties, efficient and high-quality manufacturing of micro-nano structures and the like. The application relates to a method for quantitatively regulating multiphase vanadium oxide and application design and scheme of the multiphase vanadium oxide. SUMMARY

[0004] The application aims at solving the problems of low thermal sensitivity, difficulty in miniaturization and application limitation of the existing temperature measuring device, and provides a method for quantitatively regulating multiphase vanadium oxide and application of the multiphase vanadium oxide; the temperature measuring device is processed based on femtosecond laser direct writing technology, does not need a mask, and can flexibly realize regulation of thermal sensitive material characteristics, high-precision micro-structured preparation and the like. Meanwhile, the temperature measuring device has high performance (high TCR and low noise) and high response speed, has a micro-scale thin film design (which can maximize the specific surface area of the device), and can be applied to technical fields such as calorimetric ionizing radiation dosimetry and microbolometer.

[0005] The application aims at solving the problems of low thermal sensitivity, difficulty in miniaturization and application limitation of the existing temperature measuring device, and provides a method for quantitatively regulating multiphase vanadium oxide and application of the multiphase vanadium oxide; the temperature measuring device is processed based on femtosecond laser direct writing technology, does not need a mask, and can flexibly realize regulation of thermal sensitive material characteristics, high-precision micro-structured preparation and the like. Meanwhile, the temperature measuring device has high performance (high TCR and low noise) and high response speed, has a micro-scale thin film design (which can maximize the specific surface area of the device), and can be applied to technical fields such as calorimetric ionizing radiation dosimetry and microbolometer.

[0006] A method for quantitatively regulating multiphase vanadium oxide and application of the multiphase vanadium oxide, by sequentially regulating vanadium oxide thin film material quantitatively based on femtosecond laser in a condition of oxygen (O2) filled in a quasi-vacuum environment and a condition of inert gas filled in a quasi-vacuum environment, forming multiphase vanadium oxide VO x x by etching VO x thin film material based on femtosecond laser direct writing in a condition of inert gas filled in a quasi-vacuum environment, realizing flexible and efficient processing of VO x thin film with any microstructure, forming a temperature sensitive unit; finally, depositing a metal electrode and insulating packaging, and preparing a multiphase vanadium oxide thin film temperature measuring device.

[0007] The ratio of VO2, V2O3 and V2O5 vanadium oxides formed by regulating VO2 thin film quantitatively based on femtosecond laser is (1-6):(1-5):(1-6); the microstructured VO x The thermal sensitive unit structure is square wave form, the structure period is 100-1000 μm, and the structure width is 25-250 μm.

[0008] A method for quantitatively regulating multiphase vanadium oxide and application of the multiphase vanadium oxide, including the following steps:

[0009] Step 1: using low pressure chemical vapor deposition (LPCVD) process to deposit 300 nm thick silicon nitride on a silicon wafer as a substrate for thin film material deposition, and then using magnetron sputtering technology to deposit 200 nm thick vanadium oxide material on the silicon nitride substrate and preparing VO2 thin film through annealing treatment;

[0010] Step 2: On the basis of the VO2 thin film prepared in step 1, first, irradiate the surface of the VO2 thin film material with a focused femtosecond laser beam in an oxygen-filled quasi-vacuum environment, induce local excitation of a large number of free electrons to cause lattice instability, thereby causing rapid melting and bond breaking of vanadium oxide, and re-bonding with oxygen molecules under femtosecond pulse excitation to form V2O5. In this process, the amount of VO2 to V2O5 conversion is directly related to the laser action process and the pressure in the vacuum chamber. Through first-principle calculation, the parameter design is guided to controllably adjust the VO2 to V2O5 conversion. Subsequently, on the basis of the previous step, in an inert gas-filled quasi-vacuum environment, irradiate by femtosecond laser direct writing to control the interaction process of laser and material, locally excite a large number of free electrons, promote the change of crystal lattice, induce the bond breaking and oxygen removal of vanadium oxide material. By controlling the laser flux and pulse injection, the local electron density is adjusted to control the phase transition process, and V2O3 is controllably formed. Through first-principle calculation, the laser action parameters are guided to adjust the proportion of V2O3 formation. In the above process, the processed area is characterized by X-ray photoelectron spectroscopy (XPS), the relative concentrations of VO2, V2O3, and V2O5 phases in the sample are calculated and analyzed by XPS peak fitting and area ratio of each peak, and the above parameters are further optimized to process a multiphase vanadium oxide VO x with a specific proportion of VO2, V2O3, and V2O5, to realize quantitative phase transition control of the vanadium oxide thin film;

[0011] A multiphase vanadium oxide thin film temperature measuring device is prepared by using the multiphase vanadium oxide prepared by the method of claim 1. In an inert gas-filled quasi-vacuum environment, the VO x thin film material is locally etched by femtosecond laser direct writing to realize the processing of any microstructured VO x thin film, form a temperature sensitive unit; on the basis of the temperature sensitive unit, a Au / Cr electrode is deposited by direct current sputtering, an outer layer of polyimide is spin-coated as a protective layer; then the silicon substrate is etched by etching technology, the polyimide is encapsulated, finally the lead wire is prepared by wire drawing technology and the electrical insulation is performed by using silica gel, to prepare the multiphase vanadium oxide thin film temperature measuring device.

[0012] An apparatus for realizing the above method, comprising a femtosecond laser system, a half-wave plate, a linear polarizer, a mechanical shutter, a dichroic mirror, a vacuum chamber, a gas filling device (oxygen, inert gas, etc.), a three-dimensional precision displacement platform, a beam splitter, a white light source, a charge-coupled device (CCD), an industrial computer, etc.

[0013] Connection relationship: femtosecond laser pulses are emitted from the laser, pass through the energy adjusting device composed of half-wave plate and linear polarizer, mechanical shutter in turn, are reflected and guided by the dichroic mirror to enter the vacuum cavity vertically, reach the light inlet of the objective lens, and are focused by the objective lens to irradiate the sample surface for femtosecond laser processing; the focusing objective lens, the sample to be processed and the precision moving platform are all placed in the vacuum cavity, and the sample to be processed is placed on the precision moving platform to control the exposure area and position; through the inflation device, O2, inert gas and the like can be filled into the vacuum cavity to adjust the processing atmosphere; the charge-coupled device (CCD) camera and the white light source are used to observe the entire laser processing process; the laser pulse trigger mode, the precision moving platform, the mechanical shutter, the vacuum cavity and the like are realized by the industrial computer to achieve the expected processing.

[0014] Working process:

[0015] (1) VO2 thin film is prepared by using magnetron sputtering technology to deposit vanadium oxide material on a silicon nitride substrate and performing annealing treatment;

[0016] (2) The femtosecond laser system generates Gaussian femtosecond laser, which is adjusted by half-wave plate and attenuator for uniform energy control, and is reflected by dichroic mirror to enter the vacuum cavity vertically, reaches the light inlet of the objective lens, and is focused by the objective lens to irradiate the sample surface;

[0017] (3) In the condition of filling O2 in the quasi-vacuum environment, the focused femtosecond laser beam is used to irradiate the surface of the VO2 thin film material, to induce local excitation of a large number of free electrons to cause lattice instability, so as to cause local rapid melting and bond breaking of vanadium oxide, and to re-form bonds with oxygen molecules under the excitation of femtosecond pulses, to form V2O5. In this process, the conversion amount of VO2 to V2O5 is directly related to the laser action process and the pressure of the vacuum cavity, and through first principle calculation, the parameter design is guided to control the conversion of VO2 to V2O5. Subsequently, on the basis of the above processing, in the condition of filling inert gas in the quasi-vacuum environment, the femtosecond laser direct writing irradiation is used to control the interaction process of laser and material, to locally excite a large number of free electrons, to promote the change of lattice, to induce the bond breaking of V-O in vanadium oxide material and the removal of oxygen. By controlling the laser flux and pulse injection, the local electron density is controlled, the phase change process is controlled, and V2O3 is controllably formed. Through first principle calculation, the laser action parameters are guided to adjust the formation proportion of V2O3. In the above process, X-ray photoelectron spectroscopy (XPS) is used to characterize the processed area, the relative concentration of VO2, V2O3 and V2O5 phases in the sample is calculated and analyzed through XPS peak fitting and the area ratio of each peak, and the above parameters are further optimized to process a multiphase vanadium oxide VO x , to realize quantitative phase change control of vanadium oxide film;

[0018] (4) In the quasi-vacuum environment, the VO x thin film material is not damaged by the laser action process on the silicon nitride substrate, and the material properties of the VO x thin film material do not change. The three-dimensional displacement platform is controlled by a programmed computer to drive the high-precision movement of the sample to be processed, so that any patterned high-efficiency processing and microstructured VO x thin film forms a temperature sensitive unit;

[0019] (5) Au / Cr electrodes are deposited by direct current sputtering, and an outer layer of polyimide is spin-coated as a protective layer. Then, the silicon substrate is etched by etching technology, the polyimide is encapsulated, and finally, the lead wires are prepared by wire drawing technology and electrically insulated by silicone to prepare a multiphase vanadium oxide thin film temperature measuring device.

[0020] Beneficial effects

[0021] 1. The method for quantitatively regulating multiphase vanadium oxide and the application of multiphase vanadium oxide, by regulating VO2 thin film material quantitative phase transition to form multiphase vanadium oxide VO x under the condition of quasi-vacuum environment filled with gas (oxygen, inert gas, etc.), based on femtosecond pulse induced material ultrafast dynamics. x thin film forms a temperature sensitive unit, a multiphase vanadium oxide microscale thin film temperature measuring device is prepared, which can realize the preparation of a temperature measuring device with high performance (high TCR, low noise), microscale thin film design, and can realize high-precision measurement of μK resolution micro temperature rise, and is applied to the technical fields of calorimetry ionizing radiation dosimetry and microbolometer.

[0022] 2. The method for quantitatively regulating multiphase vanadium oxide and the application of multiphase vanadium oxide, which adopts a maskless, gas-assisted processing technology, so that the system of the present application is flexible, efficient and has strong controllability of material properties.

[0023] 3. The method for quantitatively regulating multiphase vanadium oxide and the application of multiphase vanadium oxide, which has fast response speed and small disturbance, and effectively promotes the application range in the sensing application field. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic diagram of the experimental processing light path of the method for quantitatively regulating multiphase vanadium oxide and the application of multiphase vanadium oxide;

[0025] Figure 2 The flowchart of femtosecond laser regulated multiphase vanadium oxide and femtosecond laser etching processing microstructured sensitive unit is shown in the figure;

[0026] Figure 3 The schematic diagram of the preparation of a thin film temperature measuring device based on microstructured multiphase vanadium oxide is shown in the figure.

[0027] Wherein, 1-femtosecond laser, 2-half wave plate, 3-linear polarizer, 4-mechanical shutter, 5-dichroic mirror, 6-focusing objective lens, 7-sample to be processed, 8-precision displacement platform, 9-vacuum cavity, 10-gas filling device, 11-beam splitter, 12-white light source, 13-CCD, 14-industrial computer. DETAILED DESCRIPTION

[0028] The application will be further described below in conjunction with the drawings and examples.

[0029] Example 1

[0030] A method for quantitatively regulating multiphase vanadium oxide, comprising the following steps:

[0031] Step 1: depositing silicon nitride on a silicon wafer as a substrate for thin film material deposition, and then depositing vanadium oxide material on the silicon nitride substrate and performing annealing treatment to obtain a VO2 thin film;

[0032] Step 2: irradiating the surface of the VO2 thin film material with a focused femtosecond laser beam under the condition of filling O2 in a quasi-vacuum environment, inducing local excitation of a large number of free electrons to cause lattice instability, thereby causing local rapid melting and bond breaking of vanadium oxide, and re-bonding with oxygen molecules under femtosecond pulse excitation to regulate the formation of V2O5; in this process, the conversion amount of VO2 to V2O5 is directly related to the laser action process and the pressure of the vacuum cavity, and through first principle calculation, the parameter design is guided to controllably adjust the conversion of VO2 to V2O5; filling inert gas; under the condition of filling inert gas in a quasi-vacuum environment, the interaction process of laser and material is controlled through femtosecond laser direct writing irradiation, inducing V-O bond breaking and oxygen removal of the material, and locally phase changing to form V2O3; through first principle calculation, the laser action parameters are guided to adjust the formation proportion of V2O3; in the above process, the processed area is characterized by X-ray photoelectron spectroscopy (XPS), the relative concentrations of VO2, V2O3 and V2O5 phases in the sample are calculated and analyzed through XPS peak fitting and the area proportion of each peak, and the above parameters are further optimized to process a multiphase vanadium oxide VO x , realizing quantitative phase change regulation of the vanadium oxide thin film.

[0033] A method for preparing a micro-scale thin film temperature measuring device using multiphase vanadium oxide, comprising the following steps:

[0034] (1) as shown in FIG. 1, a white light source 12 is used to illuminate the sample to be processed 7, and a beam splitter 11 is used to split the reflected light into two beams, one of which is used to form a white light source for illuminating the sample to be processed 7, and the other is used to form a white light source for illuminating the sample to be processed 7. Figure 1As shown, the Ti:sapphire femtosecond laser system 1 serves as the laser source, providing a Gaussian femtosecond laser beam with a center wavelength of 800 nm and a pulse duration of 100 fs. The femtosecond pulses are controlled by an energy adjustment system consisting of a half-wave plate 2 and a linear polarizer 3, and the laser beam is switched on and off by a mechanical shutter 4. The number of pulses irradiating the sample is adjusted by controlling the opening time of the mechanical shutter and the laser repetition rate. Subsequently, the femtosecond laser beam is reflected and guided perpendicularly into the vacuum cavity 9 by a dichroic mirror 5, reaching the entrance of the objective lens 6, and then focused by the objective lens onto the surface of the sample 7 for laser processing. The sample to be processed is placed on a precision moving platform 8 to control the exposure area and position. O2, inert gases, etc., are introduced into the vacuum cavity through a gas filling device 10 to adjust the processing atmosphere.

[0035] (2) As attached Figure 2 As shown in (I-II), a 300 nm thick silicon nitride layer was deposited on a silicon wafer using low-pressure chemical vapor deposition (LPCVD) as the substrate for thin film deposition. Subsequently, a 200 nm thick vanadium oxide layer was deposited on the silicon nitride substrate using magnetron sputtering and annealed to prepare a VO2 thin film. First, under quasi-vacuum conditions filled with O2, a focused femtosecond laser beam was used to irradiate the surface of the VO2 thin film, inducing a large number of locally excited free electrons, causing lattice instability. This led to rapid local melting and bond breaking of the vanadium oxide, which then re-bonded with oxygen molecules under femtosecond pulse excitation, thus controlling the formation of V2O5. In this process, the VO2 to V2O5 transformation is directly related to the laser irradiation process and the vacuum chamber pressure. First-principles calculations guided parameter design, allowing for controllable adjustment of the VO2 to V2O5 transformation. Subsequently, based on the previous processing step, under quasi-vacuum conditions filled with inert gas, femtosecond laser direct writing irradiation was used to control the interaction between the laser and the material. This locally excited and generated a large number of free electrons, causing lattice changes and inducing VO bond breakage and oxygen removal in the vanadium oxide material. By controlling the laser flux and pulse injection, the local electron density was modulated, controlling the phase transition process and controllably forming V₂O₃. First-principles calculations guided the laser interaction parameters, adjusting the V₂O₃ formation ratio. During the above process, X-ray photoelectron spectroscopy (XPS) was used to characterize the processed area. The relative concentrations of VO₂, V₂O₃, and V₂O₅ phases in the sample were analyzed by XPS peak fitting and the area ratio of each peak, further guiding the optimization of the above parameters to form a multiphase vanadium oxide VO₂O₃ composed of VO₂, V₂O₃, and V₂O₅ in a specific ratio. x This enables quantitative phase transition control of vanadium oxide thin films;

[0036] (3) As attached Figure 2 As shown in (III-IV), under quasi-vacuum conditions filled with inert gas, VO was locally and precisely etched away by direct writing with a femtosecond laser. xThe thin film material is not damaged by the laser action process on the silicon nitride substrate, and the VO x The material properties do not change. By controlling the three-dimensional displacement platform with a programmed computer, the sample to be processed is moved with high precision, realizing efficient processing of any patterned microstructured VO x The thin film forms a temperature sensitive unit;

[0037] (4) as shown in Figure 3 (I-III), Au / Cr electrodes are deposited by direct current sputtering, and an outer layer of polyimide is spin-coated as a protective layer. Then, the silicon substrate is etched away using etching technology, and polyimide is used for packaging. Finally, wires are prepared using the wire drawing technology and electrically insulated with silicone to prepare the multiphase vanadium oxide thin film temperature measuring device.

[0038] Example 2

[0039] A method for quantitatively regulating multiphase vanadium oxide and the application of multiphase vanadium oxide, comprising the following steps:

[0040] (1) as shown in Figure 1 Titanium blue sapphire femtosecond laser system 1 as a laser source, it provides a Gaussian femtosecond laser beam, the center wavelength is 800nm, the pulse duration is 100fs. The femtosecond pulse passes through the energy adjustment system composed of half-wave plate 2 and linear polarizer 3 to control the energy, mechanical shutter 4 controls the on-off of the laser beam, and the pulse number of the sample irradiated is adjusted by controlling the opening time of the mechanical shutter and the laser repetition frequency. Subsequently, the femtosecond laser beam is reflected and guided by dichroic mirror 5 to be perpendicular to the incident into vacuum chamber 9, reaches the light inlet of objective lens 6, and is focused by the objective lens to irradiate the surface of sample 7 for laser processing; the sample to be processed is placed on the precision moving platform 8 to control the exposure area and position; through the inflation device 10, O2, inert gas and the like are filled into the vacuum chamber to adjust the processing atmosphere;

[0041] (2) as shown in Figure 2(I-II) as shown, using a low pressure chemical vapor deposition (LPCVD) process to deposit a 300 nm thick silicon nitride on a silicon wafer, used as a substrate for thin film material deposition, followed by using a magnetron sputtering technique to deposit a 200 nm thick vanadium oxide material on the silicon nitride substrate and annealing to prepare a VO2 thin film. First, in an O2-filled quasi-vacuum environment, a focused femtosecond laser beam is used to irradiate the surface of the VO2 thin film material, inducing local excitation of a large number of free electrons to cause lattice instability, resulting in rapid melting and bond breaking of vanadium oxide, and re-bonding with oxygen molecules under femtosecond pulse excitation, and the formation of V2O5 is regulated; inert gas is filled; in an inert gas-filled quasi-vacuum environment, the laser is irradiated by direct writing, the interaction process of laser and material is controlled, the V-O bond of the material is broken and oxygen is removed, and the local phase transition forms V2O3; by designing laser action parameters, the proportion of V2O3 formation can be controlled and adjusted; the processed area is characterized by X-ray photoelectron spectroscopy (XPS), the relative concentrations of VO2, V2O3, and V2O5 phases in the sample are calculated and analyzed by XPS peak fitting and the area ratio of each peak, and further guidance is provided to optimize the above parameters to process a multiphase vanadium oxide VO x with a specific proportion of VO2, V2O3, and V2O5, realizing quantitative phase transition regulation of vanadium oxide thin film. The quantitative regulation is implemented as follows: ① in the above femtosecond laser regulation process, in an O2-filled quasi-vacuum environment, the laser flux F is controlled to be 20.3 mJ / cm 2 , the effective pulse number N is 30, the repetition frequency f is 1000 Hz, and the gas pressure P is 0.2 Torr. Subsequently, in an inert gas-filled quasi-vacuum environment, the laser flux F is controlled to be 25.6 mJ / cm 2 , the effective pulse number N is 30, the repetition frequency f is 1000 Hz, and the gas pressure P is 0.5 Torr, realizing quantitative regulation of VO2 thin film material to form a multiphase vanadium oxide VO x with a ratio of VO2, V2O3, and V2O5 of 6:1:1; ② in the above femtosecond laser regulation process, in an O2-filled quasi-vacuum environment, F is controlled to be 33.7 mJ / cm 2 , N is 61, f is 1000 Hz, and P is 0.6 Torr. Subsequently, in an inert gas-filled quasi-vacuum environment, F is controlled to be 25.6 mJ / cm 2 , N is 30, f is 1000 Hz, and P is 0.5 Torr, realizing quantitative regulation of VO2 thin film material to form a multiphase vanadium oxide VO x with a ratio of VO2, V2O3, and V2O5 of 5:1:4; ③ in the above femtosecond laser regulation process, in an O2-filled quasi-vacuum environment, F is controlled to be 20.3 mJ / cm 2N = 30, f = 1000 Hz, P = 0.2 Torr. Subsequently, under quasi-vacuum conditions filled with inert gas, F was controlled to be 38.3 mJ / cm². 2 With N = 58, f = 1000 Hz, and P = 0.5 Torr, quantitative control of the formation of vanadium oxide (VO2, V2O3, V2O5) in VO2 thin film materials with a ratio of 5:4:1 was achieved. x ④ During the above femtosecond laser modulation process, under quasi-vacuum O2-filled conditions, F = 46.6 mJ / cm² was controlled. 2 N = 100, f = 1000 Hz, P = 0.8 Torr. Subsequently, under quasi-vacuum conditions filled with inert gas, F was controlled to be 51.2 mJ / cm². 2 With N = 100, f = 1000 Hz, and P = 0.5 Torr, quantitative control of the formation of vanadium oxide (VO2, V2O3, V2O5) in VO2 thin film materials with a ratio of 1:5:6 was achieved. x ;

[0042] (3) As attached Figure 2 As shown in (III-IV), under quasi-vacuum conditions filled with inert gas, VO was locally and precisely etched away by direct writing with a femtosecond laser. x Thin film materials, the laser treatment process does not damage the silicon nitride substrate, and the VO in the area not affected by the laser... x The material properties remain unchanged. A computer-controlled three-dimensional displacement platform moves the sample to be processed with high precision, enabling efficient processing of arbitrary patterns and microstructured VO. x Thin film formation of temperature-sensitive units. Microstructured VO x The thin film structure is a square waveform with a period of 160 μm and a width of 40 μm;

[0043] (4) As attached Figure 3 As shown in (I-III), an Au / Cr electrode was deposited by DC sputtering, and a layer of polyimide was spin-coated as a protective layer. Subsequently, the silicon substrate was etched away using etching technology, encapsulated with polyimide, and finally, wires were fabricated using wire drawing technology and electrically insulated with silicone to form a multiphase vanadium oxide thin-film temperature sensing device. The fabricated multiphase vanadium oxide microscale thin-film temperature sensing device is waterproof and can achieve miniaturized designs with a length ≤800μm, width ≤600μm, and thickness ≤30μm. The fabricated multiphase vanadium oxide microscale thin-film temperature sensing device exhibits a measurement repeatability of <0.1%, a TCR value better than -3% / K (3 times higher than the TCR of conventional thermistors based on metals such as Pt and Ni), and a sheet resistance of <50KΩ / sq, making it applicable to fields such as calorimetric ionizing radiation dosimetry and microbolometers.

[0044] Example 3

[0045] A method for controlling heterogeneous vanadium oxide and its application include the following steps:

[0046] (1) The Ti:sapphire femtosecond laser system 1 serves as the laser source, providing a Gaussian femtosecond laser beam with a center wavelength of 800 nm and a pulse duration of 100 fs. The femtosecond pulses are controlled by an energy adjustment system consisting of a half-wave plate 2 and a linear polarizer 3, and the laser beam is controlled by a mechanical shutter 4. The number of pulses irradiating the sample is adjusted by controlling the opening time of the mechanical shutter and the laser repetition rate. Subsequently, the femtosecond laser beam is reflected and guided perpendicularly to the entrance of the objective lens 6 by a dichroic mirror 5, and then focused by the objective lens to irradiate the surface of the sample 7 for laser processing. The sample to be processed is placed on a precision moving platform 8 to control the exposure area and position.

[0047] (2) A 300 nm thick silicon nitride layer was deposited on a silicon wafer using low-pressure chemical vapor deposition (LPCVD) as the substrate for thin film deposition. Subsequently, a 200 nm thick vanadium oxide layer was deposited on the silicon nitride substrate using magnetron sputtering and annealed to prepare a VO2 thin film. Under atmospheric conditions, a focused femtosecond laser beam was used to irradiate the surface of the VO2 thin film, inducing a local phase transition in the vanadium oxide. The laser parameters were controlled (laser flux F = (20.3-51.2) mJ / cm²). 2 Effective pulse count N = 30-100, repetition frequency f = 1000Hz;

[0048] (3) Under atmospheric conditions, VOCs are removed locally with high precision by direct writing with femtosecond laser. x Thin film materials, through a computer-controlled three-dimensional displacement platform, drive the sample to be processed with high precision, achieving efficient processing of arbitrary patterns and microstructured VOCs. x Thin film formation of temperature-sensitive units. Microstructured VO x The thin film structure is a square waveform with a period of 160 μm and a width of 40 μm;

[0049] (4) As attached Figure 3 As shown in (I-III), an Au / Cr electrode was deposited by DC sputtering, and a layer of polyimide was spin-coated as a protective layer. Subsequently, the silicon substrate was etched away using etching technology, encapsulated with polyimide, and finally, wires were fabricated using wire drawing technology and electrically insulated with silicone to form a multiphase vanadium oxide thin-film temperature sensing device. The fabricated microscale thin-film temperature sensing device has a TCR value below -1.5% / K.

[0050] The above detailed description of the specific description, the purpose, technical scheme and beneficial effects of the application are further described in detail, it should be understood that the above description is only a specific embodiment of the application, and is not used to limit the protection scope of the application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. A method for quantitatively controlling heterogeneous vanadium oxide, characterized in that: The steps include the following: Step 1: Deposit silicon nitride on a silicon wafer as a substrate for thin film material deposition, then deposit vanadium oxide on the silicon nitride substrate and perform annealing to obtain a VO2 thin film; Step 2: Under quasi-vacuum conditions filled with O2, a focused femtosecond laser beam is used to irradiate the surface of the VO2 thin film material, inducing a large number of free electrons to cause lattice instability, resulting in rapid local melting and bond breaking of vanadium oxide. Under femtosecond pulse excitation, the vanadium oxide reacts with oxygen molecules to re-bond, controlling the formation of V2O5. An inert gas is then introduced. Under quasi-vacuum conditions filled with inert gas, femtosecond laser direct writing irradiation is used to control the interaction between the laser and the material, inducing VO bond breaking and oxygen removal, leading to a local phase transition to V2O3. The V2O3 formation ratio can be controlled by designing laser interaction parameters. X-ray photoelectron spectroscopy (XPS) is used to characterize the processed area. The relative concentrations of VO2, V2O3, and V2O5 phases in the sample are calculated and analyzed by XPS peak fitting and the area ratio of each peak, further guiding the optimization of the above parameters to process and form a multiphase vanadium oxide VO2 composed of VO2, V2O3, and V2O5 in a specific ratio. x This enables quantitative phase transition control of vanadium oxide thin films; The quantitative phase transition control is as follows: ① In the above femtosecond laser modulation process, under the condition of a quasi-vacuum environment filled with O2, the laser flux is controlled. F =20.3mJ / cm 2 Valid pulse count N =30, repetition frequency f =1000Hz, air pressure intensity P =0.2Torr; Subsequently, under quasi-vacuum conditions filled with inert gas, the laser flux was controlled. F =25.6mJ / cm 2 Valid pulse count N =30, repetition frequency f =1000Hz, air pressure intensity P =0.5 Torr, achieving quantitative control of the formation of vanadium oxide (VO2, V2O3, V2O5) in VO2 thin film materials with a 6:1:1 ratio, resulting in a heterogeneous vanadium oxide (VO2, V2O3, V2O5). x ; ② During the above femtosecond laser modulation process, under the quasi-vacuum environment filled with O2, control F =33.7mJ / cm 2 , N= 61, f =1000Hz, P =0.6Torr; Subsequently, under quasi-vacuum conditions filled with inert gas, control F =25.6mJ / cm 2 , N= 30, f =1000Hz, P =0.5 Torr, achieving quantitative control of the formation of vanadium oxide (VO2, V2O3, V2O5) in VO2 thin film materials with a ratio of 5:1:4, resulting in a heterogeneous vanadium oxide (VO2, V2O3, V2O5). x ; ③ During the above femtosecond laser modulation process, under the quasi-vacuum environment filled with O2, control F =20.3mJ / cm 2 , N= 30, f =1000Hz, P =0.2Torr; Subsequently, under quasi-vacuum conditions filled with inert gas, control F =38.3mJ / cm 2 , N= 58, f =1000Hz, P =0.5 Torr, achieving quantitative control of the formation of heterogeneous vanadium oxide VO2, V2O3, V2O5 in VO2 thin film materials with a ratio of 5:4:

1. x ; ④ During the above femtosecond laser modulation process, under the quasi-vacuum environment filled with O2, control F =46.6mJ / cm 2 , N= 100, f =1000Hz, P =0.8 Torr; Subsequently, under quasi-vacuum conditions filled with inert gas, control F =51.2mJ / cm 2 , N= 100, f =1000Hz, P =0.5 Torr, achieving quantitative control of the formation of vanadium oxide (VO2, V2O3, V2O5) in VO2 thin film materials with a VO2:V2:V2O3:V2O5 ratio of 1:5:6, resulting in a heterogeneous vanadium oxide (VO2) composition. x .

2. A method for preparing a multiphase vanadium oxide thin film temperature sensing device using the multiphase vanadium oxide prepared according to claim 1, characterized in that: VO was locally etched away by direct writing using a femtosecond laser under quasi-vacuum conditions filled with inert gas. x Thin film materials for realizing arbitrary microstructured VOCs x The thin film is processed to form a temperature-sensitive unit; based on the temperature-sensitive unit, an Au / Cr electrode is deposited by DC sputtering, and a layer of polyimide is spin-coated on the outer layer as a protective layer; then the silicon substrate is etched away using etching technology, and polyimide is used for encapsulation. Finally, wires are prepared using wire drawing technology and electrically insulated with silicone to form a multiphase vanadium oxide thin film temperature sensing device.

3. An apparatus for implementing the method as described in claim 2, characterized in that: Includes femtosecond laser systems, half-wave plates, linear polarizers, mechanical shutters, dichroic mirrors, vacuum cavities, gas filling devices, three-dimensional precision displacement platforms, beam splitters, white light sources, and charge-coupled devices (CCDs). The laser emits a femtosecond laser, which passes through an energy adjustment device consisting of a half-wave plate and a linear polarizer, a mechanical shutter, and is then reflected by a dichroic mirror and directed vertically into the vacuum cavity. The laser then reaches the objective lens entrance and is focused by the objective lens before irradiating the sample surface for femtosecond laser processing. The focusing objective, the sample to be processed, and the precision positioning stage are all placed inside the vacuum chamber. The sample to be processed is placed on the precision positioning stage to control the exposure area and position. A gas filling device is used to fill the vacuum chamber with O2 and inert gas to adjust the processing atmosphere. A charge-coupled device (CCD) camera and a white light source are used to observe the entire laser processing process.

4. A method for preparing a multiphase vanadium oxide thin film temperature sensing device using the apparatus described in claim 3, characterized in that: (1) VO2 thin films were prepared by depositing vanadium oxide material on silicon nitride substrates using magnetron sputtering and then annealing them; (2) The femtosecond laser system generates Gaussian femtosecond laser, and the energy is uniformly controlled by adjusting the half-wave plate and the attenuator. The laser is reflected by the dichroic mirror and enters the vacuum cavity perpendicularly. It reaches the entrance of the objective lens and is focused by the objective lens to irradiate the sample surface. (3) Under quasi-vacuum conditions filled with O2, a focused femtosecond laser beam is used to irradiate the surface of the VO2 thin film material, inducing a large number of free electrons to cause lattice instability, thereby leading to rapid local melting and bond breaking of vanadium oxide. Under femtosecond pulse excitation, it interacts with oxygen molecules to re-bond, regulating the formation of V2O5. Inert gas is introduced. Under quasi-vacuum conditions filled with inert gas, the interaction process between the laser and the material is controlled by direct writing irradiation with a femtosecond laser, inducing VO bond breaking and oxygen removal, and local phase transformation to form V2O3. The V2O3 formation ratio can be controlled by designing laser interaction parameters. The processed area is characterized by X-ray photoelectron spectroscopy (XPS). The relative concentrations of VO2, V2O3, and V2O5 phases in the sample are calculated and analyzed by XPS peak fitting and the area ratio of each peak, further guiding the optimization of the above parameters, and processing to form a multiphase vanadium oxide VO2 composed of a specific ratio of VO2, V2O3, and V2O5. x This enables quantitative phase transition control of vanadium oxide thin films; (4) Under the condition of quasi-vacuum environment filled with inert gas, VO is removed locally with high precision by femtosecond laser direct writing. x Thin film materials, the laser treatment process does not damage the silicon nitride substrate, and the VO in the area not affected by the laser... x The material properties remain unchanged; a three-dimensional displacement platform controlled by a programmable computer moves the sample to be processed with high precision, enabling efficient processing of arbitrary patterns and microstructured VO. x Thin film forms temperature-sensitive units; (5) An Au / Cr electrode was deposited by DC sputtering, and a layer of polyimide was spin-coated on the outer layer as a protective layer. Then, the silicon substrate was etched away by etching technology, and polyimide was used for encapsulation. Finally, wires were prepared by wire drawing technology and electrically insulated with silicone to form a multiphase vanadium oxide thin film temperature measuring device.

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