A hydrogen sensor with ultrafast hydrogen response speed and a preparation method thereof

Abstract

The application provides a hydrogen sensor with superfast hydrogen response speed and a preparation method thereof, and the hydrogen sensor comprises a silicon oxide substrate and a double-fork electrode structure, the double-fork electrode structure comprises a titanium electrode layer, a tungsten reinforcing layer and a palladium sensitive layer; the silicon oxide substrate is provided with a fork electrode pattern, the titanium electrode layer covers the fork electrode pattern, the tungsten reinforcing layer covers the pin area and the bridge arm resistance area of the titanium electrode, and the palladium sensitive layer covers the titanium electrode layer and corresponds to the position of the fork electrode pattern; the titanium electrode layer is directly arranged on the silicon oxide substrate, the structure is simple, the titanium electrode is used as a bottom electrode, the sensitivity and mechanical stability of the sensor are improved, the tungsten reinforcing layer is arranged in the pin area and the bridge arm resistance area of the titanium electrode, and the overall conductivity and mechanical strength are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas sensors, in particular to a hydrogen sensor with super-fast hydrogen response speed and a preparation method thereof. BACKGROUND

[0002] Hydrogen, as a clean energy, has a wide application prospect in the fields of energy storage, fuel cells, chemical production, etc. However, hydrogen has the characteristics of flammability and explosiveness, and its explosion limit range in air is relatively wide (4.0% - 75.6%), so real-time, rapid and accurate detection of hydrogen is crucial. Traditional hydrogen sensors have problems such as slow response speed, low sensitivity and poor stability, which are difficult to meet the demand of rapid detection of hydrogen in practical application. For example, some hydrogen sensors based on electrochemical principle usually have a response time of several seconds or even tens of seconds, which cannot detect hydrogen leakage in time, and there is a great safety hazard in some scenarios with extremely high safety requirements. In addition, the existing sensors also have a relatively complex preparation process and high cost, which is not conducive to large-scale production and application. Therefore, it is of great practical significance to develop a hydrogen sensor with fast response speed, high sensitivity and simple preparation process.

[0003] A preparation method of a hydrogen sensor based on nickel oxide quantum dot material is disclosed in a Chinese patent application No. 202410285972.3, published on July 26, 2024. A substrate is provided; an insulating layer is formed on the substrate; the insulating layer is patterned to obtain a pre-suspension film structure; a seed layer is formed on the insulating layer; an electrode pattern is photoetched on the seed layer; an electrode layer with a Wheatstone bridge pattern is formed on the surface of the seed layer, and annealing treatment is performed after washing the glue; the excess seed layer and part of the substrate are removed to form a MEMS micro-heating plate with a suspension film structure and a Wheatstone bridge structure electrode; a hydrogen-sensitive material slurry is dropped on the hydrogen-sensitive area of the electrode layer to form a hydrogen-sensitive layer; wherein the hydrogen-sensitive material slurry is prepared by stirring nickel oxide quantum dots and palladium tungsten particles in a mixed solution of alpha-terpineol, isopropyl alcohol and PEG-300.

[0004] The hydrogen sensor first forms an insulating layer on the substrate, then forms a seed layer on the insulating layer, and then photoetches an electrode pattern on the seed layer. This structure is complex and has high manufacturing cost. At the same time, the mechanical strength of the sensor is low, and the sensor is prone to damage. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a hydrogen sensor with super-fast hydrogen response speed and a preparation method thereof. The titanium electrode layer is directly arranged on the silicon oxide substrate, the structure is simple, the titanium electrode is used as the bottom electrode, the sensitivity and mechanical stability of the sensor are improved, the tungsten enhancement layer is arranged in the titanium electrode pin area and the bridge arm resistance area, and the overall conductivity and mechanical strength are improved.

[0006] To solve the above technical problems, the technical solution used by the present application is:

[0007] The hydrogen sensor with super-fast hydrogen response speed provided by the present application comprises a silicon oxide substrate and a double-fork electrode structure, the double-fork electrode structure comprises a titanium electrode layer, a tungsten enhancement layer and a palladium sensitive layer; the silicon oxide substrate is provided with a fork electrode pattern, the titanium electrode layer covers the fork electrode pattern, the tungsten enhancement layer covers the pin area and the bridge arm resistance area of the titanium electrode, and the palladium sensitive layer covers the titanium electrode layer and corresponds to the position of the fork electrode pattern.

[0008] Preferably, the thickness of the titanium electrode layer is 8-12 nm, the thickness of the tungsten enhancement layer is 13-17 nm, and the thickness of the palladium sensitive layer is 11-15 nm.

[0009] Preferably, the titanium electrode layer is provided with a Wheatstone bridge circuit, the Wheatstone bridge circuit comprises a palladium film sensitive resistance R1, a palladium film sensitive resistance R2, a reference resistance R3 and a reference resistance R4; the palladium film sensitive resistance R1 and the reference resistance R4 are arranged diagonally and connected with the bridge input end, and the palladium film sensitive resistance R2 and the reference resistance R3 are arranged diagonally and connected with the bridge input end.

[0010] Preferably, the fork electrode pattern has ten pairs of forks, the finger width is 180-220 μm, the finger spacing is 30-60 μm, and the sensitive area is 7000 μm×5500 μm.

[0011] Another object of the present application is to provide a preparation method of the hydrogen sensor with super-fast hydrogen response speed, comprising the following steps:

[0012] S1, pretreating the silicon oxide substrate;

[0013] S2, photoetching a fork electrode pattern on the pretreated silicon oxide substrate;

[0014] S3, depositing a titanium electrode layer on the fork electrode pattern;

[0015] S4, depositing a tungsten enhancement layer on the pin area and the bridge arm resistance area of the titanium electrode layer;

[0016] S5, stripping the metal thin film above the photoresist not exposed on the silicon oxide substrate;

[0017] S6, depositing a palladium sensitive layer on the corresponding position of the titanium electrode layer and the tungsten enhancement layer and the fork electrode pattern.

[0018] Preferably, S1 specifically comprises sequentially placing the silicon oxide substrate into acetone, ethanol and deionized water for ultrasonic cleaning, and then drying.

[0019] Preferably, S3 is specifically depositing a titanium electrode layer on the interdigital electrode pattern by electron beam evaporation of a titanium target, and the deposition thickness of the titanium electrode layer is 8-12 nm.

[0020] Preferably, S4 is specifically depositing a tungsten enhancement layer on the pin area and bridge arm resistance area of the titanium electrode layer by electron beam evaporation of a tungsten target, and the deposition thickness of the tungsten enhancement layer is 13-17 nm.

[0021] Preferably, S6 is specifically depositing a palladium sensitive layer on the corresponding positions of the titanium electrode layer and the tungsten enhancement layer and the interdigital electrode pattern by electron beam evaporation of a palladium target, and the deposition thickness of the palladium sensitive layer is 11-15 nm.

[0022] Preferably, S5 is specifically placing the silicon oxide substrate into a stripping solution, peeling off the metal thin layer above the unexposed photoresist from the surface of the silicon oxide substrate, and then rinsing the surface of the silicon oxide substrate clean.

[0023] The hydrogen sensor with ultrafast hydrogen response speed provided by the application has the following beneficial effects compared with the prior art:

[0024] The titanium electrode layer is directly arranged on the silicon oxide substrate, and the structure is simple, and the titanium electrode has good conductivity, strong adhesion to the silicon oxide substrate, and strong hydrogen adsorption capacity. The titanium electrode as a bottom electrode improves the sensitivity and mechanical stability of the sensor. The tungsten enhancement layer improves the conductivity and mechanical strength of the pin area and the bridge arm resistance area of the titanium electrode. The palladium sensitive layer can rapidly expand the crystal lattice and instantaneously change the electronic structure when palladium and hydrogen atoms reversibly adsorb, and can respond immediately when in contact with hydrogen, thereby rapidly detecting the hydrogen concentration.

[0025] By limiting the thickness of the tungsten enhancement layer, the total resistance of the sensor is within the reasonable range of hydrogen-sensitive signal acquisition, and does not affect the shunt of the resistance change amount of the palladium membrane sensitive resistance. At the same time, it has good conductivity, and the thickness can provide good mechanical strength for the pin to avoid damage to the pin area of the titanium electrode due to use. By limiting the thickness of the palladium sensitive layer, the response speed, response degree and stability of the sensor are improved.

[0026] In the Wheatstone bridge circuit, the palladium membrane sensitive resistance is used as the working arm, and the reference resistance is used as the compensation arm to form a four-arm bridge circuit. When affected by environmental factors (temperature fluctuations, humidity fluctuations), the resistances of the working arm and the compensation arm change in the same direction and amplitude due to the symmetry of physical properties, and the bridge maintains a balanced state. When hydrogen acts on the palladium membrane sensitive resistance, the working arm changes in resistance due to hydrogen atom adsorption, while the compensation arm is not affected, and the bridge is unbalanced to output a difference signal. The common offset caused by environmental factors is cancelled out, so only the specific resistance change caused by hydrogen is retained, thereby effectively suppressing zero drift.

[0027] By limiting the shape and size of the titanium electrode formed on the interdigital electrode pattern by limiting the structure parameters of the interdigital electrode pattern, the sensitivity and response speed of the sensor can be improved by setting the parameters.

[0028] By matching the titanium electrode layer, the tungsten enhancement layer, the palladium sensitive layer and the Wheatstone bridge circuit, the response speed of the hydrogen sensor is greatly improved, the leakage of hydrogen can be detected in time, and the safety is improved; the influence time of the hydrogen sensor under 1% hydrogen concentration is less than 0.5s.

[0029] The beneficial effects of the preparation method of the hydrogen sensor with ultrafast hydrogen response speed according to the present application mainly include:

[0030] The titanium electrode layer is directly deposited on the interdigital electrode pattern, which simplifies the manufacturing process while ensuring the sensitivity and mechanical stability of the sensor; by peeling off the metal film above the unexposed photoresist on the silicon oxide substrate, the unnecessary metal film is removed, and the interdigital electrode pattern is more clear. In the pretreatment of the silicon oxide substrate, the impurities and contaminants on the surface of the silicon oxide substrate are removed, and only acetone, ethanol and deionized water are used for cleaning, which simplifies the pretreatment process. By controlling the deposition thickness of the tungsten enhancement layer, the evaporation efficiency is improved while providing better mechanical strength to the pin; by controlling the thickness of the palladium sensitive layer, the response speed, response and stability of the hydrogen sensor are improved; by controlling the thickness of the titanium electrode layer and the thickness of the palladium sensitive layer, the deposition quality of the sensitive layer is ensured. The silicon oxide substrate is placed in the stripping liquid to quickly remove the metal film above the unexposed photoresist on the silicon oxide substrate.

[0031] The present application directly sets the titanium electrode layer on the silicon oxide substrate, which is simple in structure, and uses titanium electrode as the bottom electrode to improve the sensitivity and mechanical stability of the sensor. The tungsten enhancement layer is provided in the titanium electrode pin area and the bridge arm resistance area to improve the overall conductivity and mechanical strength. BRIEF DESCRIPTION OF DRAWINGS

[0032] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present application are shown. Like reference numerals refer to like elements throughout the drawings and the figures are not necessarily drawn to scale, emphasis instead being placed upon illustrating the principles of the present application.

[0033] Figure 1 It is a hierarchical diagram of the hydrogen sensor of the present application.

[0034] Figure 2 It is a schematic diagram of the hydrogen sensor of the present application.

[0035] Figure 3 It is a sectional view of the hydrogen sensor of the present application.

[0036] Figure 4 Circuit diagram of the Wheatstone bridge circuit in the hydrogen sensor of the present application.

[0037] Figure 5a Cycle test performance curve of the hydrogen sensor of the present application at 65℃.

[0038] Figure 5b is Figure 5a Zoom-in view of 0-5 seconds in the above.

[0039] Figure 6a Curve of the hydrogen sensor of the present application at different temperatures.

[0040] Figure 6b is Figure 6a Zoom-in view of 0-5 seconds in the above.

[0041] Explanation of the reference numerals: silicon oxide substrate 1, titanium electrode layer 2, tungsten reinforcing layer 3, palladium sensitive layer 4, silicon bottom layer 5. DETAILED DESCRIPTION

[0042] The technical solutions of the present application will be further described in detail below in combination with the drawings and specific embodiments, so that those skilled in the art can better understand the present application and implement it. However, the embodiments are not intended to limit the present application. In the embodiments, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0043] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element and integrated as a whole, or there can be a middle element. The terms "mount", "one end", "the other end" and similar expressions used in the present application are only for the purpose of illustration.

[0044] As Figures 1-6b shown, a hydrogen sensor with ultrafast hydrogen response speed includes a silicon oxide substrate 1 and a double-fork electrode structure, which includes a titanium electrode layer 2, a tungsten reinforcing layer 3 and a palladium sensitive layer 4. The silicon oxide substrate 1 is provided with a fork electrode pattern, the titanium electrode layer 2 covers the fork electrode pattern, the tungsten reinforcing layer 3 covers the pin area and bridge arm resistance area of the titanium electrode, and the palladium sensitive layer 4 covers the titanium electrode layer 2 and corresponds to the position of the fork electrode pattern.

[0045] The titanium electrode layer 2 is directly arranged on the silicon oxide substrate 1, and the structure is simple, the titanium electrode has good conductivity, strong adhesion to the silicon oxide substrate 1 and strong adsorption capacity for hydrogen; the titanium electrode is used as a bottom electrode to improve the sensitivity and mechanical stability of the sensor. The tungsten reinforcing layer 3 is arranged to improve the conductivity and mechanical strength of the titanium electrode pin area and the bridge arm resistance area; the palladium sensitive layer 4 is arranged, and when palladium and hydrogen atoms reversibly adsorb, the crystal lattice rapidly expands and the electronic structure instantaneously changes, and the palladium can respond to hydrogen immediately, thereby quickly detecting the hydrogen concentration.

[0046] The thickness of the titanium electrode layer 2 is 8-12 nm, the thickness of the tungsten reinforcing layer 3 is 13-17 nm, and the thickness of the palladium sensitive layer 4 is 11-15 nm. By limiting the thickness of the tungsten reinforcing layer 3, the total resistance of the sensor is controlled to be within a reasonable range of hydrogen-sensitive signal acquisition, and the shunt effect on the resistance change of the palladium membrane sensitive resistance is avoided. In this way, the total resistance of the sensor is not too large, which causes the current in the circuit to be too small, the signal strength to be weak, the signal to be easily covered by noise, and the detection accuracy to be reduced. At the same time, the total resistance of the sensor is not too small, which causes the current to be too large to exceed the circuit range, causes the sensor to heat, and affects the adsorption properties of the palladium sensitive layer 4 to hydrogen. The total resistance of the sensor is not too small, which causes the current to be too large to cause high power consumption, and the sensor is heated, which affects the adsorption properties of the palladium sensitive layer 4 to hydrogen.

[0047] The tungsten reinforcing layer 3 with a thickness of 13-17 nm has good conductivity, and the tungsten reinforcing layer 3 has good Brinell hardness, which provides good mechanical strength for the pin and avoids damage and wear of the pin area of the titanium electrode due to use. In a preferred embodiment, a probe station is used to test the hydrogen sensor, and the pin area of the titanium electrode is covered with the tungsten reinforcing layer 3, which protects the pin area of the titanium electrode from being worn by the probe.

[0048] By limiting the thickness of the palladium sensitive layer 4, the response speed, response degree and stability of the sensor are improved. By controlling the thickness of the titanium electrode layer 2 and the thickness of the palladium sensitive layer 4, the deposition quality of the sensitive layer is ensured.

[0049] In a preferred embodiment, the thickness of the titanium electrode layer 2 is 10 nm, the thickness of the tungsten reinforcing layer 3 is 15 nm, and the thickness of the palladium sensitive layer 4 is 13 nm. Due to the limitation of the overall thickness of the hydrogen sensor, the palladium sensitive layer 4 with a thickness of 13 nm is arranged to ensure that the thickness of the palladium sensitive layer 4 is greater than the thickness of the titanium electrode layer 2. At the same time, the thickness of the palladium sensitive layer 4 is not too thick, which causes the palladium sensitive layer 4 to expand and break when absorbing hydrogen, so that the resistance cannot be restored to the reference value.

[0050] The titanium electrode layer 2 is provided with a Wheatstone bridge circuit, which comprises a palladium film sensitive resistor R1, a palladium film sensitive resistor R2, a reference resistor R3 and a reference resistor R4; the palladium film sensitive resistor R1 and the reference resistor R4 are arranged diagonally and connected with the bridge input end, and the palladium film sensitive resistor R2 and the reference resistor R3 are arranged diagonally and connected with the bridge input end.

[0051] In the Wheatstone bridge circuit, the palladium film sensitive resistor is used as a working arm, and the reference resistor is used as a compensation arm to form a four-arm bridge circuit; when affected by environmental factors such as temperature fluctuation and humidity fluctuation, the resistances of the working arm and the compensation arm change in the same direction and with the same amplitude due to the symmetry of physical properties, and the bridge maintains a balanced state; when hydrogen acts on the palladium film sensitive resistor, the working arm changes in resistance due to hydrogen atom adsorption, while the compensation arm is not affected, the bridge is unbalanced and outputs a difference signal, which offsets the common offset caused by environmental factors, so that only the specific resistance change caused by hydrogen is retained, thereby effectively inhibiting the zero drift.

[0052] Referring to Figure 2 As shown in the figure, when there is no hydrogen action, the bridge is in a balanced state, the resistance values of the palladium film sensitive resistor R1 and the reference resistor R4 are equal to those of the palladium film sensitive resistor R2 and the reference resistor R3, R1R4=R2R3, and the bridge output voltage Uout=0. When hydrogen is introduced to act on the palladium film sensitive resistor, the resistance value of the palladium film sensitive resistor will change, at which time R1R4≠R2R3, the bridge balance is broken, and the bridge will have a voltage output Uout.

[0053] The interdigital electrode pattern has ten pairs of interdigital electrodes, the finger width is 180-220 μm, the finger spacing is 30-60 μm, and the sensitive area is 7000 μm×5500 μm. In a preferred embodiment, the interdigital electrode pattern has ten pairs of interdigital electrodes, the finger width is 200 μm, the finger spacing is 50 μm, and the sensitive area is 7000 μm×5500 μm. By limiting the structure parameters of the interdigital electrode pattern, the shape and size of the titanium electrode formed on the interdigital electrode pattern are limited, and the setting of the parameters can improve the sensitivity and response speed of the sensor.

[0054] In the embodiment, a silicon bottom layer 5 is arranged at the bottom of the silicon oxide substrate 1; the silicon oxide substrate 1 is formed by thermal oxidation of the surface of the silicon bottom layer into silicon dioxide through a thermal oxidation process.

[0055] Referring to Figure 5a and Figure 5b As shown in the figure, the output parameters of the hydrogen sensor reach 90% of the stable value within 1 second in the cyclic test at a temperature of 65°C; referring to Figure 6a and Figure 6bAs shown, the response time of the hydrogen sensor at 1% hydrogen concentration is within 1 second at temperatures of 45℃, 55℃, 65℃, 75℃, 85℃ and 90℃, respectively; preferably, the response time of the hydrogen sensor is shorter at temperatures of 75℃-115℃, and the response time of the hydrogen sensor is less than 0.5s. The response time is the time required for the output parameter of the hydrogen sensor to reach 90% of the stable value after the hydrogen sensor is in contact with hydrogen.

[0056] The present application greatly improves the response speed of the hydrogen sensor by the cooperation of the titanium electrode layer 2, the tungsten enhancement layer 3, the palladium sensitive layer 4 and the Wheatstone bridge circuit, can timely detect the leakage of hydrogen, and improves the safety; the influence time of the hydrogen sensor at 1% hydrogen concentration is less than 0.5s.

[0057] A preparation method of a hydrogen sensor with ultrafast hydrogen response speed, comprising the following steps:

[0058] S1, pretreating the silicon oxide substrate 1; specifically, the silicon oxide substrate 1 is sequentially placed in acetone, ethanol and deionized water for ultrasonic cleaning, and then dried. Preferably, the silicon oxide substrate 1 is cleaned in acetone, ethanol and deionized water for 15 min, and dried with nitrogen.

[0059] S2, photoetching the interdigital electrode pattern on the pretreated silicon oxide substrate 1; preferably, presetting the sensor size parameters, using a photoetching machine to expose the pattern on the silicon oxide substrate, and then removing the photoresist in the exposed area through a developing process to obtain the interdigital electrode pattern.

[0060] S3, depositing the titanium electrode layer 2 on the interdigital electrode pattern; specifically, depositing the titanium electrode layer 2 on the interdigital electrode pattern by electron beam evaporation of titanium target material, and the deposition thickness of the titanium electrode layer 2 is 8-12 nm. Preferably, the silicon oxide substrate 1 is placed in the electron beam evaporation equipment, the vacuum degree is extracted to 3.8x10 -3 Pa below, setting the base disc rotation speed to 8r / min, depositing the titanium electrode layer 2 with a thickness of 10 nm by electron beam evaporation of titanium target material.

[0061] S4, depositing the tungsten enhancement layer 3 on the pin area and bridge arm resistance area of the titanium electrode layer 2; specifically, depositing the tungsten enhancement layer 3 on the pin area and bridge arm resistance area of the titanium electrode layer 2 by electron beam evaporation of tungsten target material, and the deposition thickness of the tungsten enhancement layer 3 is 13-17 nm. Preferably, the same vacuum degree and base disc rotation speed as when depositing the titanium electrode layer 2 are maintained, the tungsten target material is replaced, and the tungsten enhancement layer 3 with a thickness of 15 nm is deposited.

[0062] S5, stripping the metal film above the photoresist not exposed on the silicon oxide substrate 1; specifically, placing the silicon oxide substrate 1 into a stripping liquid to strip the metal film above the photoresist not exposed from the surface of the silicon oxide substrate 1, and then rinsing the surface of the silicon oxide substrate 1 clean. Preferably, the stripping liquid is NMP stripping liquid, and the silicon oxide substrate 1 is placed into the NMP stripping liquid for 5 min; then the silicon oxide substrate 1 is rinsed with deionized water.

[0063] S6, depositing the palladium sensitive layer 4 at the corresponding positions of the interdigital electrode pattern and the titanium electrode layer 2 and the tungsten enhancement layer 3; specifically, depositing the palladium sensitive layer 4 at the corresponding positions of the interdigital electrode pattern and the titanium electrode layer 2 and the tungsten enhancement layer 3 by electron beam evaporation of a palladium target, and the deposition thickness of the palladium sensitive layer 4 is 11-15 nm. Preferably, after depositing the tungsten enhancement layer 3, the silicon oxide substrate 1 is placed into an electron beam evaporation device with a metal mask clamped, the vacuum degree is extracted to 3.8x10 -3 Pa, the base disk rotation speed is set to 8 r / min, the palladium sensitive layer with a thickness of 13 nm is deposited by electron beam evaporation of a palladium target.

[0064] The above method directly deposits the titanium electrode layer 2 on the interdigital electrode pattern, which simplifies the manufacturing process while ensuring the sensitivity and mechanical stability of the sensor; the metal film above the photoresist not exposed on the silicon oxide substrate is stripped to remove the unnecessary metal film, so that the interdigital electrode pattern is clearer. The impurities and contaminants on the surface of the silicon oxide substrate 1 are removed in the pretreatment of the silicon oxide substrate 1, and the pretreatment process is simplified by using only acetone, ethanol and deionized water for cleaning. By controlling the deposition thickness of the tungsten enhancement layer 3, the evaporation efficiency is improved while providing better mechanical strength to the pin; by controlling the thickness of the palladium sensitive layer 4, the response speed, response and stability of the hydrogen sensor are improved; by controlling the thickness of the titanium electrode layer 2 in cooperation with the thickness of the palladium sensitive layer 4, the deposition quality of the sensitive layer is ensured. Placing the silicon oxide substrate 1 into the stripping liquid can quickly remove the metal film above the photoresist not exposed on the silicon oxide substrate. The cooperation of the titanium electrode layer 2, the tungsten enhancement layer 3, the palladium sensitive layer 4 and the Wheatstone bridge circuit greatly improves the response speed of the hydrogen sensor, which can detect the leakage of hydrogen in time and improve the safety; the influence time of the hydrogen sensor under 1% hydrogen concentration is less than 0.5 s.

[0065] In this specification, unless specifically stated and limited otherwise, a first feature being "on" or "under" a second feature can mean that the first and second features are directly in contact, or that the first and second features are indirectly in contact through an intermediate medium. Also, a first feature being "over", "above" and "on top of" a second feature can mean that the first feature is directly on top of or obliquely on top of the second feature, or that the first feature is merely horizontally higher than the second feature. A first feature being "under", "below" and "underneath" a second feature can mean that the first feature is directly underneath or obliquely underneath the second feature, or that the first feature is merely horizontally lower than the second feature.

[0066] In the description of the specification, the description referring to the terms "preferred embodiment", "further embodiment", "other embodiment" or "specific example" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples, without contradiction.

[0067] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary, and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A hydrogen sensor with ultrafast hydrogen response speed, characterized in that: The application relates to a silicon oxide substrate and a double-fork electrode structure, the double-fork electrode structure comprising a titanium electrode layer, a tungsten reinforcing layer and a palladium sensitive layer; an interdigital electrode pattern is arranged on the silicon oxide substrate, the titanium electrode layer covers the interdigital electrode pattern, the tungsten reinforcing layer covers the pin area and the bridge arm resistance area of the titanium electrode, and the palladium sensitive layer covers the titanium electrode layer and corresponds to the position of the interdigital electrode pattern.

2. The ultrafast hydrogen response speed hydrogen gas sensor of claim 1, wherein: The thickness of the titanium electrode layer is 8-12 nm, the thickness of the tungsten reinforcing layer is 13-17 nm, and the thickness of the palladium sensitive layer is 11-15 nm.

3. The ultrafast hydrogen response speed hydrogen gas sensor of claim 1, wherein: The titanium electrode layer is provided with a Wheatstone bridge circuit, the Wheatstone bridge circuit comprising a palladium film sensitive resistor R1, a palladium film sensitive resistor R2, a reference resistor R3 and a reference resistor R4; the palladium film sensitive resistor R1 and the reference resistor R4 are arranged at opposite angles and are connected with the bridge input end, and the palladium film sensitive resistor R2 and the reference resistor R3 are arranged at opposite angles and are connected with the bridge input end.

4. The ultrafast hydrogen response speed hydrogen gas sensor of claim 1, wherein: The interdigital electrode pattern has ten pairs of interdigital electrodes, the finger width is 180-220 mu m, the finger spacing is 30-60 mu m, and the sensitive area is 7000 mu m*5500 mu m.

5. A method for preparing a hydrogen sensor with ultrafast hydrogen response speed, characterized in that: The application further discloses a preparation method of the sensor, which comprises the following steps: S1, pretreating the silicon oxide substrate; S2, photoetching an interdigital electrode pattern on the pretreated silicon oxide substrate; S3, depositing a titanium electrode layer on the interdigital electrode pattern; S4, depositing a tungsten reinforcing layer on the pin area and the bridge arm resistance area of the titanium electrode layer; S5, stripping the metal film above the unexposed photoresist on the silicon oxide substrate; S6, depositing a palladium sensitive layer on the corresponding positions of the titanium electrode layer and the tungsten reinforcing layer and the interdigital electrode pattern.

6. The method of claim 5, wherein the hydrogen sensor has an ultrafast hydrogen response speed. S1 specifically comprises sequentially placing the silicon oxide substrate into acetone, ethanol and deionized water for ultrasonic cleaning, and then drying.

7. The method of claim 5, wherein the hydrogen sensor has an ultrafast hydrogen response speed. S3 specifically comprises depositing the titanium electrode layer on the interdigital electrode pattern by electron beam evaporation of a titanium target, and the deposition thickness of the titanium electrode layer is 8-12 nm.

8. The method of claim 5, wherein the hydrogen sensor has an ultrafast hydrogen response speed. S4 specifically comprises depositing the tungsten reinforcing layer on the pin area and the bridge arm resistance area of the titanium electrode layer by electron beam evaporation of a tungsten target, and the deposition thickness of the tungsten reinforcing layer is 13-17 nm.

9. The method of claim 5, wherein the hydrogen sensor has an ultrafast hydrogen response speed. S6 specifically comprises depositing the palladium sensitive layer on the corresponding positions of the titanium electrode layer and the tungsten reinforcing layer and the interdigital electrode pattern by electron beam evaporation of a palladium target, and the deposition thickness of the palladium sensitive layer is 11-15 nm.

10. The method of claim 5, wherein the hydrogen sensor has an ultrafast hydrogen response speed. S5 specifically comprises placing the silicon oxide substrate into a photoresist stripping solution, stripping the metal film above the unexposed photoresist on the silicon oxide substrate, stripping the surface of the silicon oxide substrate, and then rinsing the surface of the silicon oxide substrate.

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