Temperature sensor based on thermal resistance characteristics of thin film of triniobium octachloride

Abstract

The application provides a temperature sensor based on thermal resistance characteristics of a triniobium octachloride film and a manufacturing method thereof. The temperature sensor comprises a first layer substrate, a second layer substrate, a first electrode, a second electrode, a temperature sensing material layer and a protective material layer. The first layer substrate is made of a semiconductor material, the second layer substrate is made of an insulating material, and the second layer substrate covers the upper surface of the first layer substrate. The first electrode and the second electrode are isolated from each other and are manufactured on the upper surface of the second layer substrate. The temperature sensing material layer is a long strip-shaped triniobium octachloride film, and the triniobium octachloride film covers the upper surfaces of the first electrode, the second electrode and the second layer substrate. The external electrode leads of the temperature sensor are bonded on the first electrode and the second electrode. The protective material layer covers the upper surface of the temperature sensing material layer.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor temperature sensor technology, and particularly relates to a temperature sensor based on the thermal resistance characteristics of niobium octachloride (Nb3Cl8) thin film. Background Technology

[0002] Niobium octachloride, as a novel two-dimensional material, possesses excellent mechanical strength, foldability, thermal stability, and good temperature-sensitive properties. Furthermore, it exhibits memristor switching characteristics with significantly reduced resistance at high temperatures, making it suitable as a temperature-sensitive material for temperature sensors. Currently, temperature sensors can be mainly classified into resistance temperature sensors, fiber optic temperature sensors, and strain gauge temperature sensors. Among these, resistance temperature sensors are the most widely used. Temperature sensors based on the resistance effect typically exhibit a continuous and stable change in resistance with temperature, thus lacking a significant switching effect, which limits the improvement of the sensor's sensitivity and sensing range. Summary of the Invention

[0003] To address the limitation on sensitivity and sensing range caused by the insignificant thermal resistance effect in conventional temperature sensors, this invention provides a temperature sensor based on the memristor switching characteristics of a niobium octachloride thin film. Compared to the temperature-sensitive materials used in conventional thermal resistance temperature sensors, the niobium octachloride thin film, while meeting basic temperature detection requirements, can also switch between conductor and insulator based on ambient temperature or memristor switching caused by high voltage, exhibiting a significant switching effect. This allows for ambient temperature detection and improves the thermal resistance sensitivity within the room temperature range.

[0004] The first aspect of the present invention provides a temperature sensor, the temperature sensor comprising: a first substrate, a second substrate, a first electrode, a second electrode, a temperature-sensing material layer of niobium octachloride thin film, and a protective material layer;

[0005] The first substrate is made of semiconductor material, the second substrate is made of insulating material, and the second substrate covers the upper surface of the first substrate.

[0006] A first electrode and a second electrode, which are isolated from each other, are fabricated on the upper surface of the second substrate;

[0007] The temperature-sensitive material layer of the niobium octachloride thin film covers the upper surface of the first electrode, the upper surface of the second electrode, and the upper surface of the second substrate, respectively; specifically, it covers the upper surface of the first electrode, the upper surface of the second electrode, and the upper surface of the second substrate between the first and second electrodes.

[0008] The external electrode lead of the temperature sensor is bonded to the first and second electrodes.

[0009] The protective material layer completely covers the upper surface of the temperature sensor and encapsulates the temperature-sensing material layer of the first electrode, the second electrode, and the niobium octachloride thin film. Preferably, the first electrode, the second electrode, and the temperature-sensing material layer of the niobium octachloride thin film are encapsulated in the space formed between the protective material layer and the second substrate.

[0010] The temperature sensor as described in the first aspect of the present invention uses silicon semiconductor as the semiconductor material and silicon dioxide as the insulating material.

[0011] The temperature sensor as described in the first aspect of the present invention, wherein the silicon semiconductor material is a P-type doped silicon semiconductor material; or the silicon semiconductor material is an N-type doped silicon semiconductor material.

[0012] As described in the first aspect of the present invention, the first electrode and the second electrode are strip-shaped thin-film electrodes made of a high conductivity material, wherein the high conductivity material includes: metallic materials and / or compound materials.

[0013] As described in the first aspect of the present invention, the temperature sensor used in the strip-shaped thin-film electrode is a metal material selected from gold, silver, copper, and aluminum, or a combination of one or more of these materials.

[0014] As described in the first aspect of the present invention, the temperature sensor has a protective material layer made of an insulating material.

[0015] As described in the first aspect of the present invention, the insulating material of the temperature sensor comprises an insulating compound material; the insulating compound material is one or more of silicone, epoxy resin, etc. The silicone is, for example, a two-component polydimethylsiloxane silicone.

[0016] A second aspect of the present invention provides a method for fabricating a temperature sensor, the method comprising the following steps:

[0017] Step 1: Select a semiconductor material as the first substrate of the sensor; clean the first substrate.

[0018] Step 2: An insulating material layer is formed on the first substrate layer to serve as the second substrate layer;

[0019] Step 3: Sputter an electrode layer on the second substrate and use photolithography to divide the electrode layer into a first electrode and a second electrode that are isolated and insulated from each other.

[0020] Step 4: Fabricate a niobium octachloride thin film layer.

[0021] Step 5: Transfer the niobium octachloride thin film to the upper surfaces of the first and second electrodes;

[0022] Step 6: After the niobium octachloride thin film cools naturally at room temperature, wire bonding of the first and second electrodes is performed to obtain an unencapsulated temperature sensor, which is then encapsulated using a protective material layer.

[0023] As described in the second aspect of the present invention, in step 2, the method of forming an insulating material layer on the first substrate includes: oxidizing or nitriding a semiconductor material to form an insulating material layer.

[0024] Step 4 includes the following sub-steps:

[0025] Step 4.1: Under an argon atmosphere, high-purity niobium pentachloride and niobium are thoroughly mixed and then placed into a quartz tube;

[0026] Step 4.2: Vacuum the quartz tube and heat-seal it.

[0027] Step 4.3: Heat the quartz tube to the high-temperature crystallization temperature at a predetermined heating rate, and maintain the high-temperature crystallization temperature for a predetermined single crystallization time;

[0028] Step 4.4: After the single crystallization time is reached, turn off the heating equipment and allow the quartz tube to cool naturally.

[0029] Step 4.5: Cut open the quartz tube and select the niobium octachloride single crystal from the quartz tube.

[0030] The predetermined heating rate mentioned in step 4.3 above is, for example, 1-5 °C / min. The predetermined single crystallization time is, for example, 100-200 hours.

[0031] As described in the second aspect of the present invention, step 5 includes the following sub-steps:

[0032] Step 5.1: Use the adhesive side of the heat-release tape to attach the niobium octachloride single crystal from top to bottom;

[0033] Step 5.2, repeat step 5.1 until a continuous light green translucent niobium octachloride film is formed on the adhesive side of the heat release tape;

[0034] Step 5.3: Apply the heat-release tape with the niobium octachloride film to the top of the insulating material layer, and ensure that the niobium octachloride film covers the first electrode and the second electrode;

[0035] Step 5.4: Heat the non-adhesive side of the heat-release tape, for example, to 120°C, until the heat-release tape detaches spontaneously from the insulating material layer and the upper surfaces of the first and second electrodes. If the heat-release tape is transparent, it can also be heated until it becomes opaque and detaches spontaneously from the insulating material layer and the upper surfaces of the first and second electrodes.

[0036] As described in the second aspect of the present invention, step 6 includes the following sub-steps:

[0037] Step 6.1: Mix the A and B components of the two-component silicone (polydimethylsiloxane) according to the specified ratio and stir until a large number of bubbles appear.

[0038] Step 6.2: Place the unencapsulated sensor into a petri dish and pour liquid silicone to a level 0.5-1.5 mm above the upper surface of the unencapsulated sensor;

[0039] Step 6.3: Place the petri dish into the vacuum vessel, use a mechanical pump to evacuate for 10-30 minutes, and then maintain the vacuum state for 10-24 hours.

[0040] Step 6.4: Remove the petri dish, cut off the excess silicone around the edges, and obtain the encapsulated temperature sensor.

[0041] This invention addresses the problem that the insignificant thermal resistance effect of conventional temperature sensors limits the improvement of sensor sensitivity and sensing range. It provides a temperature sensor based on the memristor switching characteristics of niobium octachloride thin film. While meeting basic temperature detection requirements, the niobium octachloride thin film can also switch between conductor and insulator based on the memristor switching caused by high ambient temperature or strong current thermal effects, exhibiting a significant switching effect. This allows for ambient temperature detection and improves the thermal resistance sensitivity within the room temperature range. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the temperature sensor structure proposed in this invention.

[0043] Figure 2 A graph showing the relationship between the test voltage and the resistance of the temperature sensor in a specific implementation method;

[0044] Figure 3 A graph showing the relationship between the measured temperature of the temperature sensor and the current flowing through the temperature sensor in a specific implementation method.

[0045] Figure 4 The graph shows the relationship between the current flowing through the temperature sensor and the sensor input voltage in a specific implementation.

[0046] Wherein: 1-first substrate, 2-second substrate, 3-1.first electrode, 3-2.second electrode, 4-temperature sensing material layer, 5-protective material layer. Detailed Implementation

[0047] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0048] The first aspect of the present invention provides a temperature sensor, the temperature sensor comprising: a first substrate 1, a second substrate 2, a first electrode 3-1, a second electrode 3-2, a temperature-sensing material layer 4 of a strip-shaped niobium octachloride thin film, and a protective material layer 5;

[0049] The first substrate 1 is made of P-type doped silicon semiconductor material, and the second substrate 2 is a silicon dioxide layer, which covers the upper surface of the first substrate 1.

[0050] The first electrode 3-1 and the second electrode 3-2, which are isolated from each other, are fabricated on the upper surface of the second substrate 2;

[0051] The niobium octachloride thin film layer 4 covers the upper surface of the first electrode 3-1, the upper surface of the second electrode 3-2, and the upper surface of the second substrate 2, respectively; the niobium octachloride thin film layer 4 may cover part or all of the upper surface of the first electrode 3-1, the upper surface of the second electrode 3-2, and the upper surface of the second substrate 2.

[0052] The external electrode lead of the temperature sensor is bonded to the first and second electrodes.

[0053] A protective material layer 5, made of polydimethylsiloxane, completely covers the upper surface of the temperature sensor. The area covered by the protective material layer includes: a first substrate, a second substrate, a first electrode, a second electrode, and a temperature-sensing material layer of niobium octachloride thin film.

[0054] A second aspect of the present invention provides a method for fabricating a temperature sensor, the method comprising the following steps:

[0055] Step 1: Select silicon semiconductor material as the first substrate of the sensor; perform routine cleaning on the first substrate;

[0056] Step 2: Fabricate a silicon dioxide insulating material layer on the first substrate;

[0057] Step 3: Sputter a gold electrode layer onto the insulating material layer, and use photolithography to divide the gold electrode layer into a first electrode and a second electrode that are isolated from and insulated from each other.

[0058] Step 4: Fabricate a niobium octachloride thin film layer.

[0059] Step 5: Transfer the niobium octachloride thin film to the upper surfaces of the first and second electrodes;

[0060] Step 6: After the niobium octachloride thin film cools naturally at room temperature, the first electrode and the second electrode lead bonding is performed to obtain an unencapsulated temperature sensor, which is then encapsulated using a polydimethylsiloxane protective material layer.

[0061] As described in the second aspect of the present invention, in step 2, the method of forming an insulating material layer on a silicon semiconductor material substrate includes: oxidizing a silicon semiconductor material to form a silicon dioxide insulating material layer.

[0062] Step 4 includes the following sub-steps:

[0063] Step 4.1: Under an argon atmosphere, high-purity niobium pentachloride and niobium are thoroughly mixed and then placed into a quartz tube;

[0064] Step 4.2: Vacuum the quartz tube and heat-seal it.

[0065] Step 4.3: Heat the quartz tube to the high-temperature crystallization temperature at a predetermined heating rate, and maintain the high-temperature crystallization temperature for a predetermined single crystallization time.

[0066] Step 4.4: After the single crystallization time is reached, turn off the heating equipment and allow the quartz tube to cool naturally.

[0067] Step 4.5: Cut open the quartz tube and select the niobium octachloride single crystal from the quartz tube.

[0068] In step 4.3, the quartz tube is heated to a high-temperature crystallization temperature of 817°C at a predetermined heating rate of 1°C / min, and maintained at 817°C for a predetermined single crystallization time of 168 hours. After the predetermined single crystallization time is reached, the heating furnace is turned off and natural cooling is performed. The quartz tube is cut open, and niobium octachloride single crystals are selected from the quartz tube.

[0069] As described in the second aspect of the present invention, the transfer method in step 5 employs a heat-release tape transfer method.

[0070] Step 5 includes the following sub-steps:

[0071] Step 5.1: Use the adhesive side of the heat-release tape to attach the niobium octachloride single crystal from top to bottom;

[0072] Step 5.2, repeat step 5.1 until a continuous light green translucent niobium octachloride film is formed on the adhesive side of the heat release tape;

[0073] Step 5.3: Apply heat-release tape with a niobium octachloride thin film to the top of the first electrode, the second electrode, and the insulating material layer between the first electrode and the second electrode;

[0074] Step 5.4: Heat the non-adhesive side of the heat release tape to 120°C until the heat release tape detaches from the insulating material layer and the upper surfaces of the first and second electrodes.

[0075] As described in the second aspect of the present invention, step 6 includes the following sub-steps:

[0076] Step 6.1: Mix the A and B components of polydimethylsiloxane in the specified ratio and stir until a large number of bubbles appear;

[0077] Step 6.2: Place the sensor in a petri dish and pour liquid polydimethylsiloxane up to 1 mm above the top surface of the unencapsulated temperature sensor;

[0078] Step 6.3: Place the petri dish into the vacuum vessel, use a mechanical pump to evacuate for 30 minutes, and then maintain the vacuum state for 24 hours;

[0079] Step 6.4: Remove the petri dish, cut off the excess polydimethylsiloxane around the edges, and obtain the encapsulated temperature sensor.

[0080] Example

[0081] Sample preparation

[0082] (a) Si / SiO2 was selected as the substrate, with a length, width, and thickness of 1.5 × 10⁻⁶. 5 μm×1.5×10 5 (a) A 200 nm thick gold electrode with a spacing of 5 μm is sputtered on the silicon dioxide substrate. (b) A niobium octachloride film is transferred to the sputtered electrode substrate using a thermal release tape transfer method. After the niobium octachloride film cools naturally at room temperature, wire bonding and polydimethylsiloxane protective layer encapsulation are performed to complete the sample preparation.

[0083] The temperature sensor described above, based on the switching characteristics of a niobium octachloride thin-film memristor, has a substrate with dimensions of 1.5 × 10⁻⁶ mm (length, width, and thickness). 5 μm×1.5×10 5 The thickness of the Si electrode is 500 μm × 500 μm, the thickness of the SiO2 electrode is 300 nm, the thickness of the gold electrode is 200 nm, and the spacing between the electrodes is 5 μm.

[0084] Test steps

[0085] The sensor testing principle of this invention is as follows: a heating stage is used to simulate different ambient temperatures, the sensor is connected to an active device Keithley 2400s, its output current is tested under constant voltage, and its IV curve is obtained. The obtained data is analyzed using Origin to obtain the performance parameters of the temperature sensor of this invention.

[0086] The specific test steps are as follows: (a) Fix the sensor on the heating stage and connect the gold electrode leads to the two ports of the Keithley 2400s. (b) Set the heating stage hot plate parameters to 40℃. After the hot plate temperature stabilizes at 40℃, wait 10 minutes for the sensor temperature to fully stabilize. Set the Keithley 2400s scanning voltage to -2V to 2V, take 40 sampling points, repeat 3 times, and set the point test delay time to 0.4s. After completing the scan, export the data to Excel format. (c) Repeat steps (b) to increase the temperature from 40℃ to 260℃ in 20℃ increments. Because the protective material layer of the test circuit will change shape above 260℃, the hot plate temperature is set to a maximum of 200℃ to ensure the repeatability and stability of the sensor test. (d) Input the obtained IV data into Origin for processing and fitting. Analyze the relevant performance of the sensor.

[0087] The niobium octachloride thin-film temperature sensor designed in this invention, based on memristor switching characteristics, has a sensitivity of up to 2.70% / ℃ and a linearity of 0.9917, with a temperature sensing range of 40℃-260℃.

[0088] Figure 1 This is a schematic diagram of the sensor structure of the present invention.

[0089] Figure 2 This is a graph showing the relationship between the sensor's test voltage and resistance at low test voltages at room temperature. The purpose is to investigate the effect of the test voltage on this temperature sensor.

[0090] Figure 3 This graph shows the relationship between the measured temperature and the current flowing through the sensor when the test voltage is fixed. The data shows the change in current through the temperature sensor as a function of temperature. By fitting this data using Origin software and performing related calculations, we can obtain relevant data such as the linearity and sensitivity of the temperature sensor. Based on the fitted data, the linearity of the sensor is 0.9917, and the sensitivity is 2.70% / ℃.

[0091] Figure 4 This is a graph showing the relationship between the current through the sensor and the sensor input voltage at room temperature. The strong current thermal effect drives the sensor's thermistor material to undergo a memristor transition, causing the sensor's resistance to switch between conductor and insulator states.

[0092] Experiments have confirmed that using niobium octachloride thin film material with memristor transition characteristics can improve the temperature sensitivity of the thermal resistance temperature sensor while enhancing its thermal resistance sensitivity in the memristor transition temperature range. Furthermore, based on the traditional thermal resistance temperature sensor, a switching effect controlled by the memristor transition temperature is introduced at high temperatures, enabling a switching between conductors and insulators.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit them. Although the embodiments of the present invention have been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the embodiments of the present invention should not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A temperature sensor based on thermal resistance characteristics of a thin film of triniobium octachloride, characterized by, The temperature sensor comprises a first layer substrate, a second layer substrate, a first electrode, a second electrode, a temperature sensing material layer of a thin film of triniobium octachloride and a protective material layer; The first layer substrate is made of semiconductor material, and the second layer substrate is made of insulating material and covers the upper surface of the first layer substrate; The first electrode and the second electrode, which are isolated from each other, are made on the upper surface of the second layer substrate; The temperature sensing material layer of the thin film of triniobium octachloride covers the upper surfaces of the first electrode, the second electrode and the second layer substrate respectively; External electrode leads of the temperature sensor are bonded on the first electrode and the second electrode; The protective material layer completely covers the upper surface of the temperature sensor and realizes encapsulation of the first electrode, the second electrode and the temperature sensing material layer of the thin film of triniobium octachloride.

2. The temperature sensor of claim 1, wherein, The semiconductor material is silicon semiconductor, and the insulating material is silicon dioxide.

3. The temperature sensor of claim 2, wherein, The silicon semiconductor material is P-type doped silicon semiconductor material or N-type doped silicon semiconductor material.

4. The temperature sensor of claim 1, wherein, The first electrode and the second electrode are strip-shaped thin film electrodes made of high-conductivity material, and the high-conductivity material includes metal material and / or compound material.

5. The temperature sensor of claim 4, wherein, The metal material used by the strip-shaped thin film electrode is one of gold, silver, copper and aluminum or a combination of one or more of the above materials.

6. The temperature sensor of claim 1, wherein, The protective material layer is made of insulating material.

7. The temperature sensor of claim 6, wherein the temperature sensor is configured to output a signal indicative of the temperature of the temperature sensor. The insulating material includes insulating compound material, and the insulating compound material is one of silica gel and epoxy resin or a combination of one or more of the above materials.

8. The method for preparing a temperature sensor based on the thermal resistance characteristics of a thin film of triniobium octachloride according to any one of claims 1 to 7, characterized in that, The preparation method comprises the following steps: Step 1: selecting semiconductor material as the first layer substrate of the sensor and performing conventional cleaning on the first layer substrate; Step 2: making an insulating material layer on the first layer substrate as the second layer substrate; Step 3: sputtering an electrode layer on the insulating material layer and dividing the electrode layer into the first electrode and the second electrode which are isolated from each other and insulated from each other by using a photolithography method; Step 4: making a triniobium octachloride single crystal film layer; Step 5: transferring the triniobium octachloride thin film to the upper surfaces of the first electrode and the second electrode; Step 6: after the triniobium octachloride thin film is naturally cooled at room temperature, performing lead bonding of the first electrode and the second electrode to obtain an unpackaged temperature sensor, and encapsulating the temperature sensor by using a protective material layer.

9. The method of claim 8, wherein, In step 2, the method for making the insulating material layer on the first layer substrate includes oxidizing or nitriding the semiconductor material layer to make the insulating material layer.

10. The method of claim 8, wherein, The step 4 comprises the following sub-steps: Step 4.1: mixing high-purity niobium pentachloride with niobium in an argon atmosphere and loading the mixture into a quartz tube; Step 4.2: vacuumizing the quartz tube and heat-sealing the tube; Step 4.3: heating the quartz tube to a high-temperature crystallization temperature at a predetermined heating rate and maintaining the quartz tube at the high-temperature crystallization temperature for a predetermined single-crystallization time; Step 4.4: after the single-crystallization time is reached, turning off the heating device and naturally cooling the quartz tube; Step 4.5: cutting open the quartz tube and picking out the triniobium octachloride single crystal from the quartz tube.

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