Quick-response graphene high-temperature temperature sensor and preparation method thereof

Abstract

The invention discloses a fast-response graphene high-temperature temperature sensor and a preparation method thereof, and belongs to the technical field of sensors. The fast-response graphene high-temperature temperature sensor comprises a metal substrate, and an insulating layer, a metal electrode layer, a graphene sensing layer, a ceramic layer and a metal multilayer anti-oxidation layer which are sequentially arranged on the metal substrate. According to the invention, the ceramic and the quaternary metal multilayer gradient anti-oxidation coating are used to form a composite protection structure, so that compared with the single use of ceramic, the thickness of the original protection structure is greatly reduced on the basis of ensuring the anti-oxidation performance, and the problem of large residual stress retention caused by overlarge thickness is avoided; the use of the multi-layer gradient structure can ensure that the thermal expansion coefficient difference between the transition layers is small, and the thermal stress is reduced, so that the reliability and durability of the sensor are improved, and the thermal response speed of the sensor can be improved by virtue of excellent thermal conductivity of the quaternary metal multi-layer gradient anti-oxidation coating.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a fast-response graphene high-temperature temperature sensor and a preparation method thereof. Background Art

[0002] Spacecraft will experience severe aerodynamic heating during flight, which affects the safety of the aircraft during flight. Flight thermal environment data is related to the design of thermal protection system. Therefore, the temperature parameters of the aircraft are particularly important. In order to reflect the changes in the heating state of the aircraft wall, the temperature sensor is required to not only work stably at high temperatures but also have a faster response speed.

[0003] In an oxygen-free environment, graphene can work normally at a high temperature of 2100°C. Graphene can stably exist in an oxygen-free high-temperature environment and its thermal conductivity is as high as 5300W / (m·K). Therefore, the sensor made of graphene film has a very short response time to temperature. However, the conventional graphene high-temperature temperature sensor has a low thermal conductivity and slow temperature conduction due to the fact that the substrate material and protective structure are mostly ceramic structures, which limit the sensor's response speed and are not suitable for instantaneous high-temperature measurement. Therefore, it is necessary to improve the sensor's substrate material and protective structure. Summary of the invention

[0004] In order to solve the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a fast-response graphene high-temperature temperature sensor and a preparation method thereof, so as to solve the problem that the existing graphene high-temperature temperature sensor has low thermal conductivity and slow temperature conduction.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a fast-response graphene high-temperature temperature sensor is provided, comprising: a metal substrate and an insulating layer, a metal electrode layer, a graphene sensing layer, a ceramic layer and a metal multilayer anti-oxidation layer sequentially arranged on the metal substrate.

[0006] The beneficial effects of the present invention are as follows: the present invention uses metal as a substrate, and the metal multi-layer gradient anti-oxidation layer isolates oxygen. Due to the high thermal conductivity of the metal substrate and the anti-oxidation coating, the thermal response speed of the resistive graphene high-temperature temperature sensor is greatly improved. At the same time, the graphene sensing layer is wrapped by a ceramic layer, and the outermost metal multi-layer gradient anti-oxidation coating is used to effectively isolate the sensor from oxygen, and the gradient structure reduces the thermal stress of the sensor, thereby improving the high temperature resistance and stability of the graphene sensor. It has the technical characteristics of fast response, high accuracy, good protection, etc., and can be widely used in transient testing of aerospace vehicles. It is an ideal high-temperature temperature sensor with high practical value.

[0007] On the basis of the above technical solution, the present invention can also be improved as follows:

[0008] Furthermore, the thickness of the metal substrate is 500-1000 μm; the thickness of the insulating layer is 100-300 nm; the thickness of the metal electrode layer is 10-50 nm; and the thickness of the ceramic layer is 200-600 nm.

[0009] Furthermore, the metal substrate is a metal material, such as a stainless steel alloy or a cemented carbide.

[0010] Furthermore, the insulating layer is made of ceramic material, such as aluminum nitride ceramic.

[0011] Further, the metal electrode layer consists of wiring, internal interconnect electrodes, and vertical platinum electrodes connected to the sensor pads.

[0012] Furthermore, the internal interconnection electrodes are made of metal platinum.

[0013] Furthermore, the graphene sensing layer is a single-layer graphene film, such as a single-layer graphene film with a thickness of 0.34 nm.

[0014] Furthermore, the ceramic layer is silicon nitride ceramic.

[0015] Furthermore, the metal multilayer anti-oxidation layer includes a first metal anti-oxidation layer, a second metal anti-oxidation layer, a third metal anti-oxidation layer and a fourth metal anti-oxidation layer; the thicknesses of the first metal anti-oxidation layer, the second metal anti-oxidation layer, the third metal anti-oxidation layer and the fourth metal anti-oxidation layer are 30-50nm, 1-2μm, 0.5-1μm and 0.3-0.7μm respectively.

[0016] Furthermore, the first metal anti-oxidation layer is titanium nitride; the second metal anti-oxidation layer is titanium aluminum nitride; the third metal anti-oxidation layer is titanium aluminum silicon nitride; and the fourth metal anti-oxidation layer is titanium silicon nitride.

[0017] The present application sequentially deposits a first metal anti-oxidation layer, a second metal anti-oxidation layer, a third metal anti-oxidation layer and a fourth metal anti-oxidation layer on the ceramic layer to form a metal anti-oxidation coating. The structure and composition of the four layers all show a gradient change, thereby minimizing the difference in thermal expansion coefficients between layers as much as possible, enhancing the bonding strength of the coating, resisting the expansion of cracks, and extending the service life of the coating.

[0018] Specifically, when preparing the metal anti-oxidation coating, the nitrogen flow rate is controlled to circulate. During the process of linear change of the nitrogen flow rate, the nitrogen content of each layer in the coating will also change gradually, thereby forming a continuous transition of the metal anti-oxidation coating, so that the thermal expansion coefficient of the coating changes from 9.4×10 -6 It gradually decreases and then increases slowly to 8.9×10 -6 , which makes the structure and composition of the metal anti-oxidation coating change gradually.

[0019] The method for preparing the above-mentioned fast-response graphene high-temperature temperature sensor comprises the following steps:

[0020] (1) depositing an insulating layer on a metal substrate;

[0021] (2) heating the deposited insulating layer to 900-1100°C, keeping the temperature for 80-100 minutes and then cooling it naturally;

[0022] (3) coating the surface of the insulating layer treated in step (2) with photoresist, then sequentially performing pre-baking, exposure and post-baking, and finally developing the metal substrate with a developer;

[0023] (4) removing excess insulating layer and photoresist, and cleaning and drying the metal substrate;

[0024] (5) depositing a metal electrode layer on the surface of the insulating layer obtained in step (4), then attaching a graphene sensing layer on the surface of the metal electrode layer, and finally depositing a ceramic layer on the graphene sensing layer;

[0025] (6) applying photoresist on the ceramic layer, and then performing pre-baking, exposure and post-baking in sequence, and finally developing the metal substrate with a developer;

[0026] (7) removing the excess ceramic layer and photoresist, and cleaning and drying the metal substrate;

[0027] (8) depositing a metal multilayer gradient anti-oxidation layer on the ceramic layer obtained in step (7);

[0028] (9) removing the ceramic layer and the metal multilayer gradient anti-oxidation layer perpendicular to the surface of the platinum electrode in the metal electrode layer to open a window for the graphene high-temperature temperature sensor;

[0029] (10) The released vertical platinum electrode is raised to form a sensor pad, and finally a fast-response graphene high-temperature temperature sensor is obtained.

[0030] The above deposition can be carried out by atomic layer deposition process, magnetron sputtering process, plasma enhanced chemical vapor deposition technology, etc.

[0031] The present invention has the following beneficial effects:

[0032] The fast-response graphene high-temperature temperature sensor provided by the present invention is a graphene high-temperature temperature sensor based on a metal-ceramic composite substrate. The sensor can measure the externally applied temperature value by detecting the current change of the graphene sensing layer. At the same time, in this process, the insulating layer and the metal substrate and the ceramic protective layer and the metal multi-layer gradient anti-oxidation coating effectively isolate the graphene sensing layer from direct contact with the outside world, providing oxygen-free protection for the graphene sensing layer.

[0033] The present invention utilizes a metal substrate with relatively high melting point and hardness and a metal anti-oxidation protective layer packaging structure to make the sensor have good high temperature resistance, anti-interference and anti-corrosion properties, and can effectively ensure the use effect of the sensor in harsh working environments.

[0034] Compared with the graphene high-temperature temperature sensor with traditional substrate and ceramic protective layer, the present invention adopts a metal-ceramic composite substrate and a metal multi-layer gradient anti-oxidation coating. Under the same substrate and coating thickness, due to the high thermal conductivity of the metal, it can quickly transmit the external temperature and has the advantage of faster response.

[0035] The present invention uses ceramic and quaternary metal multilayer gradient anti-oxidation coating to form a composite protection structure. Compared with the use of ceramics alone, the thickness of the original protection structure is greatly reduced while ensuring the anti-oxidation performance, avoiding the problem of large residual stress retention caused by excessive thickness. Moreover, the use of the multilayer gradient structure can ensure that the difference in thermal expansion coefficients between transition layers is small, reducing thermal stress, thereby improving the reliability and durability of the sensor. The quaternary metal multilayer gradient anti-oxidation coating can improve the thermal response speed of the sensor by virtue of its excellent thermal conductivity.

[0036] The present invention can improve the shortcoming of slow response speed of traditional graphene high-temperature temperature sensors, and provide an important hardware foundation and technical means for the optimization and innovation of temperature measurement methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the cross-sectional structure of a graphene high-temperature temperature sensor.

[0038] Figure 2 Schematic diagram of the cross-sectional structure of the metal electrode layer of the graphene high-temperature temperature sensor.

[0039] Figure 3 This is a schematic diagram of the top view structure of the graphene sensing layer and the metal electrode layer of the graphene high-temperature temperature sensor.

[0040] Figure 4 Schematic diagram of the graphene sensing layer of the graphene high-temperature temperature sensor.

[0041] Figure 5 Schematic diagram of the structure of the ceramic layer of the graphene high-temperature temperature sensor.

[0042] Among them, 1-metal substrate; 2-insulating layer; 3-metal electrode layer; 4-graphene sensing layer; 5-ceramic layer; 6-first metal anti-oxidation coating; 7-second metal anti-oxidation coating; 8-third metal anti-oxidation coating; 9-third metal anti-oxidation coating; 10-wiring; 11-internal interconnection electrode; 12-vertical platinum electrode; 13-sensor pad. DETAILED DESCRIPTION

[0043] The following examples are only used to explain the present invention and are not intended to limit the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0044] Embodiment 1:

[0045] A fast-response graphene high-temperature temperature sensor comprises: a metal substrate 1 and an insulating layer 2, a metal electrode layer 3, a graphene sensing layer 4, a ceramic layer 5, a first metal anti-oxidation coating 6, a second metal anti-oxidation coating 7, a third metal anti-oxidation coating 8, and a fourth metal anti-oxidation coating 9 which are sequentially arranged on the metal substrate 1.

[0046] Among them, the metal electrode layer is composed of wiring 10, internal interconnection electrode 11 and vertical platinum electrode 12 connected to sensor pad 13; the internal interconnection electrode 11 is metal platinum, the internal interconnection electrode 11 is respectively connected to the two ends of the graphene sensing layer 4, and the vertical platinum electrode 12 is connected to the internal interconnection electrode 11 through the wiring 10.

[0047] The material of the metal substrate is 316 stainless steel alloy; the material of the insulating layer is aluminum nitride ceramic; the graphene sensing layer is a single-layer graphene film; the ceramic layer is silicon nitride ceramic; the first metal anti-oxidation layer is titanium nitride; the second metal anti-oxidation layer is titanium aluminum nitride; the third metal anti-oxidation layer is titanium aluminum silicon nitrogen; and the fourth metal anti-oxidation layer is titanium silicon nitride.

[0048] The graphene sensing layer in the above-mentioned fast-response graphene high-temperature temperature sensor is a bent structure, such as a "disc"-shaped bent structure similar to the spiral shape of mosquito coils, or other bent structures.

[0049] The above-mentioned fast-response graphene high-temperature temperature sensor is prepared by the following method:

[0050] (1) Wiping and cleaning a metal substrate with a side length of 1 cm and a thickness of 0.5 cm to remove severe contamination on the surface of the metal substrate, and controlling the surface roughness to 100-400 nm through grinding and chemical mechanical polishing;

[0051] (2) A magnetron sputtering process is used to obtain an insulating layer with a thickness of 100 nm on the surface of the metal substrate obtained in step (1); wherein the specific conditions of the magnetron sputtering process are: vacuuming to 6×10 4 Pa, oxygen and argon were introduced, pre-sputtering was performed for 5 minutes to remove impurities and oxide layer on the target surface, and then formal sputtering was started, the deposition temperature was 200 °C, the sputtering power was 60 W, and the target material was aluminum target;

[0052] (3) treating the insulating layer by an annealing process, specifically: heating the deposited insulating layer to 1000°C, keeping the temperature for 90 minutes, and then cooling it naturally to eliminate defects;

[0053] (4) Etching the insulating layer, the specific process is as follows: a layer of photoresist with a thickness of 1-5 μm is evenly coated on the treated insulating layer, the metal substrate with the insulating layer and the photoresist is pre-baked at 100°C for 90 seconds, the pre-baked metal substrate is exposed to light using a mask on a photolithography machine for 14 seconds, and then placed in a developer PD-238 for development for 60 seconds, and finally the metal substrate is post-baked at 120°C for 30 minutes; the excess insulating layer on the metal substrate is etched using a metal dry etching process, and then it is placed in acetone for 15 minutes, and the photoresist is removed using a degumming machine, and finally the metal substrate is cleaned and blown dry; wherein the degumming machine power is 300W, the O2 concentration is 300sccm, and the degumming time is 10 minutes;

[0054] (5) A metal electrode layer with a thickness of 50 nm was deposited on the surface of the insulating layer obtained in step (4) by magnetron sputtering and stripping process; the specific process conditions were: the substrate was cleaned with acetone alcohol, the wafer was baked in an oven at 120°C for 30 minutes, and then pretreated in a HMDS vacuum oven for 15 minutes to improve the adhesion between the substrate and the photoresist. NR9-3000PY negative photoresist was spin-coated, and two steps of photoresist were set. The first step was to rotate at a speed of 700 r / min for 9 seconds, and the second step was to rotate at a speed of 4000 r / min for 40 seconds. Pre-bake at 120°C for 90 seconds to harden the film. Photolithography was performed using a Canon N-550 photolithography machine with an exposure time of 14 seconds. Medium bake at 120°C for 90 seconds. The wafer was developed using negative developer RD-6 for 70 seconds. The electrode layer was sputtered using a magnetron sputtering coater with a pressure of 2 Pa, an Ar flow rate of 110 sccm, and a power of 400 W. Soak the sheet in acetone solution for 5 minutes to peel off the metal electrode;

[0055] The metal electrode layer has wiring, internal interconnect electrodes and vertical platinum electrodes connected to sensor pads;

[0056] (6) Use graphene transfer technology to adhere a single layer of graphene to the surface of the metal electrode layer. The specific process is as follows: Use one-step transfer graphene (TTG) to cut the graphene into a size of 1.5 cm × 1.5 cm. Use a dropper to gently drop water around the TTG to fully wet the TTG. Use tweezers to clamp the edge of the filter membrane and slowly put it into the water to allow the graphene to be completely released in the water and soak for 2 hours. Use tweezers to clamp the substrate to pick up the graphene, and use the vibration generated by the water droplets to smooth the graphene while picking it up. Gradually transfer the graphene to the required substrate. After the transfer, the substrate should be upright for 2 minutes to allow the water to drip out completely, then dry for 30 minutes, and then bake at 100°C for 20 minutes. Then soak in acetone. Soak in acetone three times at room temperature to remove the glue. Prepare three cups of acetone solution, soak in the first cup for 3 minutes, soak in the second cup for 5 minutes, and soak in the third cup for 10 minutes. The acetone liquid surface completely immerses the upper surface of the graphene. Then put it in an oven and dry it for 10 minutes; use graphene patterning technology to obtain the graphene sensing layer. The specific process is: clean the substrate with acetone alcohol, bake the sheet in an oven at 120°C for 30 minutes, and pre-treat it in an HMDS vacuum oven for 15 minutes. Spin-coat AZ-601 positive photoresist and set up two-step glue spreading. The first step is to rotate at a speed of 700r / min for 9s, and the second step is to rotate at a speed of 3000r / min for 40s. Pre-bake at 100°C for 90s to harden the film. Use an LED photolithography machine for exposure processing with an exposure time of 14s. Use developer PD-238 to develop the film for 60s. After the film is naturally dried, use a Plasma degumming machine to pattern the graphene. After the graphene patterning is completed, place the film in acetone for 15 minutes to remove the photoresist;

[0057] (7) using plasma enhanced chemical vapor deposition technology to deposit a ceramic layer with a thickness of 400 nm on the graphene sensing layer; during the plasma enhanced chemical vapor deposition process, the deposition temperature is 300° C., the radio frequency power is 80 W, the SiH4 concentration is 19 sccm, the NH3 concentration is 8 sccm, and the N2 concentration is 541 sccm;

[0058] (8) Etching the ceramic layer, the specific process is as follows: a layer of photoresist with a thickness of 1-5 μm is evenly coated on the ceramic layer, and then pre-baked at 100°C for 90 seconds, and the pre-baked metal substrate is exposed to light using a mask on a photolithography machine for 14 seconds, and then placed in a developer PD-238 for development treatment for 60 seconds, and finally the metal substrate is post-baked at 120°C for 30 minutes; the excess ceramic layer is etched using a reactive ion etching process at an etching rate of 1000 A / min, and then placed in acetone for 15 minutes, and the photoresist is removed using a degumming machine, and finally cleaned and blown dry; wherein the degumming machine power is 300 W, the O2 concentration is 300 sccm, and the degumming time is 10 minutes;

[0059] (9) Using cathode arc ion plating technology, a first metal anti-oxidation coating with a thickness of 0.0417 μm, a second metal anti-oxidation coating with a thickness of 1.5083 μm, a third metal anti-oxidation coating with a thickness of 0.95 μm, and a fourth metal anti-oxidation coating with a thickness of 0.5 μm are sequentially deposited on the ceramic layer obtained in step (8); the specific process of cathode arc ion plating technology is as follows: evacuate the gas pressure so that it is not higher than 0.6 Pa, and approximately reach vacuum. The temperature inside the furnace chamber is gradually heated to 450°C, and the heating time is 15 minutes. Then argon gas is introduced, and the substrate bias is maintained at -800V. Under the action of a strong electric field, ionized argon gas and titanium ions move along the direction of the electric field, bombard the substrate surface, and complete the cleaning work. The Ti target and the TiSi alloy target are opened, and the two targets evaporate at high temperature to form an ion flow that collides with the argon gas. The substrate bias is adjusted from -900V to -700V, and the argon ions bombard the substrate surface to complete ion etching, and the etching time is 15 minutes. Temperature 420℃, pressure 3Pa, control the power-on sequence of the four targets and the N2 flow rate, and deposit the four layers of the coating in sequence. First turn off the N2, then turn off the bias power supply and the target, the temperature is 160℃, and cool to room temperature with the furnace;

[0060] (10) using a plasma etching process to remove the ceramic layer, the first metal anti-oxidation coating, the second metal anti-oxidation coating, the third metal anti-oxidation coating and the fourth metal anti-oxidation coating on the surface of the vertical platinum electrode, and opening a window for the graphene high-temperature temperature sensor; the specific process of the plasma etching process is: power 200 W, etching rate 100 nm / min, chamber pressure 15000 mTorr, etching gas CHF3, SF6 and He, CHF3 gas concentration of 10 sccm, SF6 gas concentration of 8 sccm, He gas concentration of 150 sccm;

[0061] (11) Using magnetron sputtering and stripping technology, the vertical platinum electrode released by etching in step (10) is raised to form a sensor pad, and finally a fast-response graphene high-temperature temperature sensor is obtained; the specific process of magnetron sputtering and stripping technology is: pressure 2Pa, Ar flow rate 110sccm, power 400W. The wafer is placed in an acetone solution and soaked for 5 minutes to strip the metal electrode.

[0062] Embodiment 2:

[0063] A fast-response graphene high-temperature temperature sensor comprises: a metal substrate 1 and an insulating layer 2, a metal electrode layer 3, a graphene sensing layer 4, a ceramic layer 5, a first metal anti-oxidation coating 6, a second metal anti-oxidation coating 7, a third metal anti-oxidation coating 8, and a fourth metal anti-oxidation coating 9 which are sequentially arranged on the metal substrate 1.

[0064] Among them, the metal electrode layer is composed of wiring 10, internal interconnection electrode 11 and vertical platinum electrode 12 connected to sensor pad 13; the internal interconnection electrode 11 is metal platinum, the internal interconnection electrode 11 is respectively connected to the two ends of the graphene sensing layer 4, and the vertical platinum electrode 12 is connected to the internal interconnection electrode 11 through the wiring 10.

[0065] The material of the metal substrate is WC-12Co cemented carbide; the material of the insulating layer is aluminum nitride ceramic; the graphene sensing layer is a single-layer graphene film; the ceramic layer is silicon nitride ceramic; the first metal anti-oxidation layer is titanium nitride; the second metal anti-oxidation layer is titanium aluminum nitride; the third metal anti-oxidation layer is titanium aluminum silicon nitrogen; and the fourth metal anti-oxidation layer is titanium silicon nitride.

[0066] The graphene sensing layer in the above-mentioned fast-response graphene high-temperature temperature sensor is a bent structure, such as a "disc"-shaped bent structure similar to the spiral shape of mosquito coils, or other bent structures.

[0067] The above-mentioned fast-response graphene high-temperature temperature sensor is prepared by the following method:

[0068] (1) Wiping and cleaning a metal substrate with a side length of 0.8 cm and a thickness of 0.5 cm to remove severe contamination on the surface of the metal substrate, and controlling the surface roughness to 100-400 nm through grinding and chemical mechanical polishing;

[0069] (2) An atomic layer deposition process is used on the surface of the metal substrate obtained in step (1) to obtain an insulating layer with a thickness of 200 nm. The specific process of the atomic layer deposition process is as follows: ultrasonically clean the atomic layer deposition (ALD) device with acetone solution, heat the ALD chamber to 300°C, place the metal substrate in the ALD reaction chamber, and use a carrier gas device to introduce two precursors, TMA (Al(CH3)3) and water (H2O), into the reaction chamber, and self-chemically adsorb with the substrate surface for 30ms; after sufficient reaction of 2Al(CH3)3+3H2O=Al2O3+6CH4, extract the reaction by-product gas CH4, clean the collective surface and the reaction chamber for 10s, and obtain a single-layer aluminum oxide film with CH3 surface groups; transport deionized water to the reaction chamber through a carrier gas device, react chemically with the single-layer aluminum oxide with CH3 surface groups for 100ms, and generate an aluminum oxide coating on the substrate; after the deionized water pulse ends, extract the reaction by-product CH4 and residual deionized water in the chamber, clean the tool surface and the reaction chamber for 10s, and complete a cycle. The ALD cycle was repeated 1806 times to prepare a 200nm thick Al2O3 coating. ALD process parameters: the vacuum pressure of the reaction chamber was about 100Pa, and the reaction chamber was kept at a constant temperature of 300℃.

[0070] (3) treating the insulating layer by an annealing process, specifically: heating the deposited insulating layer to 1000°C, keeping the temperature for 90 minutes, and then naturally cooling it to room temperature to eliminate defects;

[0071] (4) Etching the insulating layer, the specific process is as follows: a layer of photoresist with a thickness of 1-5 μm is evenly coated on the treated insulating layer, the metal substrate with the insulating layer and the photoresist is pre-baked at 100°C for 90 seconds, the pre-baked metal substrate is exposed to light using a mask on a photolithography machine for 14 seconds, and then placed in a developer PD-238 for development for 60 seconds, and finally the metal substrate is post-baked at 120°C for 30 minutes; the excess insulating layer on the metal substrate is etched using a metal dry etching process, and then it is placed in acetone for 15 minutes, and the photoresist is removed using a degumming machine, and finally the metal substrate is cleaned and blown dry; wherein the degumming machine power is 300W, the O2 concentration is 300sccm, and the degumming time is 10 minutes;

[0072] (5) A metal electrode layer with a thickness of 40 nm was deposited on the surface of the insulating layer obtained in step (5) by magnetron sputtering and stripping process; the specific process conditions were: the substrate was cleaned with acetone alcohol, the wafer was baked in an oven at 120°C for 30 minutes, and then pretreated in a HMDS vacuum oven for 15 minutes to improve the adhesion between the substrate and the photoresist. NR9-3000PY negative photoresist was spin-coated, and two steps of photoresist were set. The first step was to rotate at a speed of 700 r / min for 9 seconds, and the second step was to rotate at a speed of 4000 r / min for 40 seconds. Pre-bake at 120°C for 90 seconds to harden the film. Photolithography was performed using a Canon N-550 photolithography machine with an exposure time of 14 seconds. Medium bake at 120°C for 90 seconds. The wafer was developed using negative developer RD-6 for 70 seconds. The electrode layer was sputtered using a magnetron sputtering coater with a pressure of 2 Pa, an Ar flow rate of 110 sccm, and a power of 400 W. Soak the sheet in acetone solution for 5 minutes to peel off the metal electrode;

[0073] The metal electrode layer has wiring, internal interconnect electrodes and vertical platinum electrodes connected to sensor pads;

[0074] (6) Use graphene transfer technology to adhere a single layer of graphene to the surface of the metal electrode layer. The specific process is as follows: Use one-step transfer graphene (TTG) to cut the graphene into a size of 1.5 cm × 1.5 cm. Use a dropper to gently drop water around the TTG to fully wet the TTG. Use tweezers to clamp the edge of the filter membrane and slowly put it into the water to allow the graphene to be completely released in the water and soak for 2 hours. Use tweezers to clamp the substrate to pick up the graphene, and use the vibration generated by the water droplets to smooth the graphene while picking it up. Gradually transfer the graphene to the required substrate. After the transfer, the substrate should be upright for 2 minutes to allow the water to drip out completely, then dry for 30 minutes, and then bake at 100°C for 20 minutes. Then soak in acetone. Soak in acetone three times at room temperature to remove the glue. Prepare three cups of acetone solution, soak in the first cup for 3 minutes, soak in the second cup for 5 minutes, and soak in the third cup for 10 minutes. The acetone liquid surface completely immerses the upper surface of the graphene. Then put it in an oven and dry it for 10 minutes; and use graphene patterning technology to obtain the graphene sensing layer. The specific process is: clean the substrate with acetone alcohol, bake the sheet in an oven at 120°C for 30 minutes, and pre-treat it in an HMDS vacuum oven for 15 minutes. Spin-coat AZ-601 positive photoresist and set up two-step glue spreading. The first step is to rotate at a speed of 700r / min for 9s, and the second step is to rotate at a speed of 3000r / min for 40s. Pre-bake at 100°C for 90s to harden the film. Use an LED photolithography machine for exposure processing with an exposure time of 14s. Use developer PD-238 to develop the film for 60s. After the film is naturally dried, use a Plasma degumming machine to pattern the graphene. After the graphene patterning is completed, place the film in acetone for 15 minutes to remove the photoresist;

[0075] (7) Using low pressure chemical vapor deposition (LPCVD) technology to deposit a ceramic layer with a thickness of 500 nm on the graphene sensing layer; the specific process parameters are: low pressure 50 Pa, temperature 700 ° C, low stress mode;

[0076] (8) Etching the ceramic layer; the specific process is: evenly spin-coat a layer of 1-5μm thick positive photoresist AZ-601 on the ceramic layer, then pre-bake at 100°C for 90s. After spin-coating AZ-601, use a mercury lamp lithography machine to expose it for 14s. Then place it in the developer PD-238 for development for 60s, and finally post-bake the metal substrate at 120°C for 30min; use the reactive ion etching process to etch the excess ceramic layer, reactive ion etcher (model: NE-550H), RF power: 300W, bias power: 30W, C4F8 concentration: 10sccm, CF4 concentration: 40sccm. Then place it in acetone and soak for 15min, and use a degumming machine to remove the photoresist, and finally clean and blow dry; among which, the degumming machine power is 300W, the O2 concentration is 300sccm, and the degumming time is 10min;

[0077] (9) Using cathode arc ion plating technology, a first metal anti-oxidation coating with a thickness of 0.0417 μm, a second metal anti-oxidation coating with a thickness of 1.5083 μm, a third metal anti-oxidation coating with a thickness of 0.95 μm, and a fourth metal anti-oxidation coating with a thickness of 0.5 μm are sequentially deposited on the ceramic layer obtained in step (8); the specific process of cathode arc ion plating technology is as follows: evacuate the gas pressure so that it is not higher than 0.6 Pa, and approximately reach vacuum. The temperature inside the furnace chamber is gradually heated to 450°C, and the heating time is 15 minutes. Then argon gas is introduced, and the substrate bias is maintained at -800V. Under the action of a strong electric field, ionized argon gas and titanium ions move along the direction of the electric field, bombard the substrate surface, and complete the cleaning work. The Ti target and the TiSi alloy target are opened, and the two targets evaporate at high temperature to form an ion flow that collides with the argon gas. The substrate bias is adjusted from -900V to -700V, and the argon ions bombard the substrate surface to complete ion etching, and the etching time is 15 minutes. Temperature 420℃, pressure 3Pa, control the power-on sequence of the four targets and the N2 flow rate, and deposit the four layers of the coating in sequence. First turn off the N2, then turn off the bias power supply and the target, the temperature is 160℃, and cool to room temperature with the furnace;

[0078] (10) using a plasma etching process to remove the ceramic layer, the first metal anti-oxidation coating, the second metal anti-oxidation coating, the third metal anti-oxidation coating and the fourth metal anti-oxidation coating on the surface of the vertical platinum electrode, and opening a window for the graphene high-temperature temperature sensor; the specific process of the plasma etching process is: power 200 W, etching rate 100 nm / min, chamber pressure 15000 mTorr, etching gas CHF3, SF6 and He, CHF3 gas concentration of 10 sccm, SF6 gas concentration of 8 sccm, He gas concentration of 150 sccm;

[0079] (11) Using magnetron sputtering and stripping technology, the vertical platinum electrode released by etching in step (10) is raised to form a sensor pad, and finally a fast-response graphene high-temperature temperature sensor is obtained; the specific process of magnetron sputtering and stripping technology is: pressure 2Pa, Ar flow rate 110sccm, power 400W. The wafer is placed in an acetone solution and soaked for 5 minutes to strip the metal electrode.

[0080] The fast-response graphene high-temperature temperature sensor proposed in the present invention can measure the externally applied temperature value by detecting the current change of the graphene sensing layer. At the same time, in this process, the insulating layer and the metal substrate and the protective layer and the metal multi-layer gradient anti-oxidation coating effectively isolate the graphene sensing layer from direct contact with the outside world, providing oxygen-free protection for the graphene sensing layer. The traditional graphene temperature sensor has a low measurement temperature range, currently mostly below 300°C, and the response time is affected by the conventional substrate and is mostly around 100ms. However, the high temperature resistance of the present invention can reach 25°C to 1500°C, can work stably at a high temperature of 1500°C, and the transient response time is 12ms.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fast-response graphene high-temperature temperature sensor, characterized in that: include: A metal substrate and an insulating layer, a metal electrode layer, a graphene sensing layer, a ceramic layer and a metal multilayer anti-oxidation layer which are sequentially arranged on the metal substrate.

2. The fast-response graphene high-temperature temperature sensor according to claim 1, characterized in that: The thickness of the metal substrate is 500-1000 μm; the thickness of the insulating layer is 100-300 nm; the thickness of the metal electrode layer is 10-50 nm; and the thickness of the ceramic layer is 200-600 nm.

3. The fast-response graphene high-temperature temperature sensor according to claim 1 or 2, characterized in that: The metal base is made of stainless steel alloy or hard alloy; the insulating layer is made of ceramic material.

4. The fast-response graphene high-temperature temperature sensor according to claim 1 or 2, characterized in that: The metal electrode layer consists of wiring, internal interconnect electrodes, and vertical platinum electrodes connecting the sensor pads.

5. The fast-response graphene high-temperature temperature sensor according to claim 4, characterized in that: The internal interconnect electrodes are made of platinum.

6. The fast-response graphene high-temperature temperature sensor according to claim 1, characterized in that: The graphene sensing layer is a single-layer graphene film.

7. The fast-response graphene high-temperature temperature sensor according to claim 1, characterized in that: The ceramic layer is silicon nitride ceramic.

8. The fast-response graphene high-temperature temperature sensor according to claim 1, characterized in that: The metal multilayer anti-oxidation layer includes a first metal anti-oxidation layer, a second metal anti-oxidation layer, a third metal anti-oxidation layer and a fourth metal anti-oxidation layer; the thicknesses of the first metal anti-oxidation layer, the second metal anti-oxidation layer, the third metal anti-oxidation layer and the fourth metal anti-oxidation layer are 30-50nm, 1-2μm, 0.5-1μm and 0.3-0.7μm respectively.

9. The fast-response graphene high-temperature temperature sensor according to claim 8, characterized in that: The first metal anti-oxidation layer is titanium nitride; the second metal anti-oxidation layer is titanium aluminum nitride; the third metal anti-oxidation layer is titanium aluminum silicon nitride; and the fourth metal anti-oxidation layer is titanium silicon nitride.

10. The method for preparing the fast-response graphene high-temperature temperature sensor according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) depositing an insulating layer on a metal substrate; (2) heating the deposited insulating layer to 900-1100°C, keeping the temperature for 80-100 minutes and then cooling it naturally; (3) coating the surface of the insulating layer treated in step (2) with photoresist, then sequentially performing pre-baking, exposure and post-baking, and finally developing the metal substrate with a developer; (4) removing excess insulating layer and photoresist, and cleaning and drying the metal substrate; (5) depositing a metal electrode layer on the surface of the insulating layer obtained in step (4), then attaching a graphene sensing layer on the surface of the metal electrode layer, and finally depositing a ceramic layer on the graphene sensing layer; (6) applying photoresist on the ceramic layer, and then performing pre-baking, exposure and post-baking in sequence, and finally developing the metal substrate with a developer; (7) removing the excess ceramic layer and photoresist, and cleaning and drying the metal substrate; (8) depositing a metal multilayer gradient anti-oxidation layer on the ceramic layer obtained in step (7); (9) removing the ceramic layer and the metal multilayer gradient anti-oxidation layer perpendicular to the surface of the platinum electrode in the metal electrode layer to open a window for the graphene high-temperature temperature sensor; (10) The released vertical platinum electrode is raised to form a sensor pad, and finally a fast-response graphene high-temperature temperature sensor is obtained.

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