Gallium nitride temperature sensor and its preparation method and application

Abstract

The application discloses a gallium nitride temperature sensor and a preparation method and application thereof. The gallium nitride temperature sensor comprises a gallium nitride layer, a tunneling layer, a cathode and an anode, the tunneling layer is arranged on at least a part of the surface of the gallium nitride layer, and an electrode hole is arranged on the tunneling layer; the cathode is arranged in the electrode hole and is in contact with the gallium nitride layer; and the anode is arranged on a part of the surface of the tunneling layer, and the anode is not in contact with the cathode. The temperature sensor adopts a new type of metal-tunneling layer-gallium nitride structure, utilizes the principle that the probability of carrier tunneling through the tunneling layer increases after being excited by heat, that is, the thermal tunneling effect, detects the size of the tunneling current to realize temperature detection and sensing, and has the advantages of high temperature resistance, high linearity and high sensitivity, and can better meet the temperature measurement requirements of application scenes such as high power and high temperature.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor materials, and in particular relates to a gallium nitride temperature sensor and a preparation method and application thereof. Background Art

[0002] Temperature sensors are sensors that sense temperature and convert it into a usable output signal. They are widely used across various industries. Traditional temperature sensors are primarily thermistors or thermocouples. Thermistors are simple to manufacture but have poor linearity, while thermocouples have low accuracy. Silicon-based CMOS temperature sensors, while highly linear, have a limited operating range, generally below 120°C. Summary of the Invention

[0003] The present invention aims to at least partially address one of the technical problems in the related art. To this end, one object of the present invention is to provide a gallium nitride temperature sensor, a method for preparing the same, and applications thereof, to meet the performance requirements of temperature sensors for high temperature resistance, high linearity, and high sensitivity in various application scenarios.

[0004] The present invention is mainly proposed based on the following problems:

[0005] Gallium nitride (GaN) is a wide-bandgap semiconductor material. GaN-based devices are widely used in new energy vehicles, rail transit, aerospace, and other fields. These applications often involve high power consumption and high temperatures, requiring device or system temperature monitoring for thermal management and improved reliability. While GaN-based Schottky diode temperature sensors can also detect temperature, their temperature sensitivity is relatively low, typically 1-2mV / K.

[0006] To this end, in one aspect of the present invention, a gallium nitride temperature sensor is provided. According to an embodiment of the present invention, the temperature sensor includes:

[0007] Gallium nitride layer;

[0008] a tunneling layer, the tunneling layer being disposed on at least a portion of the surface of the gallium nitride layer, and the tunneling layer being provided with an electrode hole;

[0009] a cathode disposed in the electrode hole and in contact with the gallium nitride layer;

[0010] An anode is provided on a portion of the surface of the tunneling layer, and the anode is not in contact with the cathode.

[0011] Compared with the prior art, the gallium nitride temperature sensor of the above embodiment of the present invention adopts a novel metal-tunneling layer-gallium nitride structure. It utilizes the principle that the probability of carriers tunneling through the tunneling layer increases after thermal excitation, namely the thermally induced tunneling effect. By detecting the magnitude of the tunneling current, it realizes temperature detection and sensing. It has the advantages of high temperature resistance, high linearity and high sensitivity, and can better meet the temperature measurement requirements of high-power and high-temperature application scenarios.

[0012] In addition, the gallium nitride temperature sensor according to the above embodiment of the present invention may also have the following additional technical features:

[0013] In some embodiments of the present invention, the thickness of the tunneling layer is 0.5-10 nm; and / or the material of the tunneling layer is at least one selected from silicon dioxide, hafnium oxide, aluminum oxide, titanium oxide, silicon nitride and aluminum nitride.

[0014] In some embodiments of the present invention, the gallium nitride layer satisfies at least one of the following conditions: the thickness of the gallium nitride layer is 50 nm to 50 μm; the gallium nitride layer is an undoped gallium nitride layer, an n-type doped gallium nitride layer, or a p-type doped gallium nitride layer; and the gallium nitride layer is a single crystal layer.

[0015] In some embodiments of the present invention, the cathode material is at least one selected from Ti, Ni, Al, Pt, W, TiN and Au; and / or the anode material is at least one selected from Ti, Ni, Au and Al.

[0016] In some embodiments of the present invention, the gallium nitride temperature sensor further includes: a substrate, wherein the gallium nitride layer is provided on at least a portion of a surface of the substrate.

[0017] In some embodiments of the present invention, the gallium nitride temperature sensor further includes: a gallium nitride buffer layer, the gallium nitride buffer layer being disposed on at least a portion of the surface of the substrate, and the gallium nitride layer being disposed on at least a portion of the surface of the gallium nitride buffer layer.

[0018] In some embodiments of the present invention, the cathode and anode are set to be forward biased or reverse biased, the electric field direction of the forward bias is from the metal layer to the gallium nitride layer, and the electric field direction of the reverse bias is from the gallium nitride layer to the metal layer.

[0019] Based on the same inventive concept, according to a second aspect of the present invention, the present invention provides a method for preparing a gallium nitride temperature sensor. According to an embodiment of the present invention, the method includes:

[0020] (1) forming a gallium nitride layer;

[0021] (2) forming a tunneling layer on at least a portion of the surface of the gallium nitride layer, and etching an electrode hole in the tunneling layer;

[0022] (3) preparing an ohmic contact electrode in the electrode hole to form a cathode;

[0023] (4) Depositing a metal layer on a portion of the surface of the tunneling layer to form an anode.

[0024] The method for preparing a gallium nitride temperature sensor according to the above embodiment of the present invention is not only simple in process, but also adopts a novel metal-tunneling layer-gallium nitride structure. Based on the thermally induced tunneling effect, the gallium nitride temperature sensor can detect and sense temperature by detecting the magnitude of the tunneling current. It has the advantages of high temperature resistance, high linearity, and high sensitivity, and can better meet the temperature measurement requirements of high-power and high-temperature application scenarios.

[0025] In some embodiments of the present invention, in step (1), a gallium nitride layer is formed on at least a portion of the surface of the substrate; alternatively, a gallium nitride buffer layer is formed in advance on at least a portion of the surface of the substrate, and then the gallium nitride layer is formed on at least a portion of the surface of the gallium nitride buffer layer.

[0026] According to a third aspect of the present invention, a method for measuring temperature using a gallium nitride temperature sensor is also provided. According to an embodiment of the present invention, the gallium nitride temperature sensor is the aforementioned gallium nitride temperature sensor or is manufactured using the aforementioned method for manufacturing a gallium nitride temperature sensor. The temperature measurement method includes: measuring the current value or voltage value between the cathode and anode of the gallium nitride temperature sensor at different temperatures to obtain a current-temperature curve or a voltage-temperature curve; directly or indirectly contacting the gallium nitride temperature sensor with a device under test, measuring the current value or voltage value between the cathode and anode, and obtaining the temperature of the device under test based on the measured current value and the current-temperature curve or the measured voltage value and the voltage-temperature curve. Compared with existing technologies, this temperature measurement method can not only be performed in high-temperature environments but also adapt to high-power applications. It can better measure or monitor the temperature of the device under test and has the advantages of high-temperature resistance, high linearity, high sensitivity, and high reliability.

[0027] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0029] Figure 1is a structural schematic diagram of a gallium nitride temperature sensor according to an embodiment of the present application.

[0030] Figure 2 is a structural schematic diagram of a gallium nitride temperature sensor according to another embodiment of the present application.

[0031] Figure 3 is a schematic diagram of a thermal tunneling effect principle of a gallium nitride temperature sensor according to an embodiment of the present application.

[0032] Figure 4 is a flow chart of a method for manufacturing a gallium nitride temperature sensor according to an embodiment of the present application.

[0033] Figure 5 is a flow chart of a method for temperature measurement using a gallium nitride temperature sensor according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which like or similar elements are denoted by the same or similar reference signs, and the embodiments described below are examples for explaining the present application and are not to be construed as limiting the present application.

[0035] In the description of the present application, it is to be understood that the terms "thickness", "upper", "lower", and the like indicate the positional or orientation relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element 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. In the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, in the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be that the first feature is directly above or obliquely above the second feature, or it only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be that the first feature is directly below or obliquely below the second feature, or it only means that the horizontal height of the first feature is less than that of the second feature.

[0036] In one aspect of the present invention, a gallium nitride temperature sensor is provided. Figure 1 It is understood that the temperature sensor includes: a gallium nitride layer 4, a tunneling layer 3, a cathode 2 and an anode 1. The tunneling layer 3 is provided on at least a portion of the surface of the gallium nitride layer 4, and an electrode hole (not shown) is provided on the tunneling layer; the cathode 2 is provided in the electrode hole and contacts the gallium nitride layer 4; the anode 1 is provided on a portion of the surface of the tunneling layer 4, and the anode 1 does not contact the cathode 2. The inventors have found that the temperature can be reflected by detecting the tunneling current based on the thermal tunneling effect, referring to Figure 3 It is understood that when a tunneling layer is inserted between the metal layer and the gallium nitride layer, under a certain bias, carriers tunnel from the metal side to the gallium nitride side or vice versa. As the temperature increases, the carriers are thermally excited to a certain energy level, and the probability of carriers passing through the tunneling layer increases, resulting in an increase in the concentration of tunneling carriers. This tunneling carrier concentration changes with temperature (i.e., the thermally induced tunneling effect). As a result, a metal electrode can be pre-formed to form a good ohmic contact electrode with the gallium nitride layer and deposited on the tunneling layer. The temperature change is reflected by measuring the current change between the anode and cathode. Compared with the existing technology, this gallium nitride temperature sensor adopts a novel metal-tunneling layer-gallium nitride structure. It utilizes the principle that the probability of carriers tunneling through the tunneling layer after thermal excitation increases, i.e., the thermally induced tunneling effect. It detects and senses temperature by detecting the magnitude of the tunneling current. It has the advantages of high temperature resistance, high linearity, and high sensitivity, and can better meet the temperature measurement requirements of high-power and high-temperature application scenarios.

[0037] Reference below Figures 1-2 The gallium nitride temperature sensor according to the above embodiment of the present invention is described in detail.

[0038] According to some specific embodiments of the present invention, the thickness of the tunneling layer 3 can be 0.5 to 10 nm, for example, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm. The inventors have found that if the thickness of the tunneling layer is too small, the preparation is difficult and it is difficult to form a continuous tunneling film structure. In addition, if the thickness of the tunneling layer is too small, the reference current is also large; and if the thickness of the tunneling layer is too large, it is also difficult for carriers to pass through the tunneling layer, and fewer carriers pass through the tunneling layer, and the sensitivity is also low. In the present invention, by controlling the tunneling layer to be within the above-mentioned thickness range, it is not only beneficial to the preparation of the tunneling layer, but also can avoid the reference current being too large, while also ensuring that the gallium nitride temperature sensor has a high sensitivity.

[0039] According to still some specific embodiments of the present application, the material used to form the tunneling layer 3 can be at least one selected from silicon dioxide, hafnium oxide, aluminum oxide, titanium oxide, silicon nitride and aluminum nitride, wherein the tunneling layer can be a single layer of silicon dioxide, a single layer of hafnium oxide, a single layer of aluminum oxide, a single layer of titanium oxide, a single layer of silicon nitride or a single layer of aluminum nitride, or a composite layer formed by any of the above materials, or a multi-layered structure formed by any of the above layers, and the inventor has found that the use of the above materials to form the tunneling layer can further ensure that the finally obtained gallium nitride temperature sensor has the advantages of high temperature resistance, high linearity and high sensitivity.

[0040] According to still some specific embodiments of the present application, the gallium nitride layer 4 can be a non-doped gallium nitride layer, or an n-type doped gallium nitride layer or a p-type doped gallium nitride layer, and the inventor has found that the use of the n-type / p-type doped or non-doped gallium nitride layer can have the thermal tunneling effect, and the temperature can be detected and sensed by detecting the size of the tunneling current; and when the doped gallium nitride layer is used, the height of the potential barrier of the contact is changed, and the energy required by the carrier to pass through the tunneling layer and the probability of passing through the tunneling layer are also different, and the use of the n-type doped or p-type doped gallium nitride layer can further improve the sensitivity of the detection.

[0041] According to still some specific embodiments of the present application, the gallium nitride layer 4 can be preferably a single crystal layer, and the inventor has found that the atomic arrangement of the single crystal layer is better than that of the amorphous gallium nitride layer, and the performance of the sensor is better.

[0042] According to still some specific embodiments of the present application, referring to Figure 2It is understood that the substrate 6 can be used as a supporting structure for the gallium nitride temperature sensor. That is, a gallium nitride layer 4 can be formed on the substrate 6 in advance, and then a tunneling layer 3 can be formed on the gallium nitride layer 4. Then, a contact ohmic electrode is prepared that contacts the gallium nitride layer 4 through the tunneling layer 3 as the cathode 2, and a metal electrode deposited on the tunneling layer is prepared as the anode 1. The inventors have found that when the gallium nitride temperature sensor uses the gallium nitride layer as the supporting layer of the overall structure, if the thickness of the gallium nitride layer is too small, its overall strength is also low, the temperature sensor is easily damaged during use, and the product utilization rate is low. If the thickness of the gallium nitride layer is large, although the overall strength can be improved, the raw material cost will be significantly increased, especially when a single crystal gallium nitride layer is used, the raw material cost is even higher. In the present invention, by using the substrate as the supporting layer, the thickness of the gallium nitride layer can be reduced, and a thicker and less expensive substrate can be used to ensure the overall strength of the sensor. Therefore, the service life of the temperature sensor can be improved while ensuring the advantages of reliability and high sensitivity, while reducing the raw material cost. In addition, it should be noted that the material of the substrate used in the present invention is not particularly limited, and those skilled in the art can select it according to actual needs. For example, the substrate can be a heterogeneous substrate (for example, silicon, sapphire, silicon carbide, etc.) or a homogeneous substrate of gallium nitride (for example, an amorphous gallium nitride layer). When a homogeneous substrate is used, for example, when an amorphous or relatively low-crystal gallium nitride is used as a substrate, a gallium nitride layer with higher crystallinity or a single crystal can be directly formed on the substrate; and when a heterogeneous substrate is used, the temperature sensor can further include a gallium nitride buffer layer 5 , wherein the gallium nitride buffer layer 5 is provided on at least a portion of the surface of the substrate 6, and the gallium nitride layer 4 can be provided on at least a portion of the surface of the gallium nitride buffer layer 5. In this case, the gallium nitride buffer layer 5 can be an amorphous gallium nitride layer or a gallium nitride layer with relatively low crystallinity. The inventors have found that if a single crystal or a gallium nitride layer with high crystallinity is directly brought into contact with a foreign substrate, the interface stress between the gallium nitride layer and the substrate is large during high-temperature measurement, and the long-term reliability of the temperature sensor deteriorates. By further providing a gallium nitride buffer layer, the above-mentioned problem can be effectively solved or significantly alleviated, thereby greatly improving the long-term reliability of the temperature sensor.

[0043] According to some further specific embodiments of the present invention, the thickness of the gallium nitride layer 4 is not particularly limited, and those skilled in the art may select the thickness according to actual needs. For example, the thickness of the gallium nitride layer 4 may be 50 nm to 50 μm, or 100 nm, 500 nm, 1 μm, 5 μm, 10 μm, 20 μm, or 50 μm. When a substrate is provided in the temperature sensor, the thickness of the gallium nitride layer 4 may be relatively thin, and when no substrate is provided in the temperature sensor, the thickness of the gallium nitride layer 4 may be relatively thick, thereby ensuring both the detection sensitivity and the overall strength of the sensor.

[0044] According to some other specific embodiments of the present invention, the materials of the cathode 2 and the anode 1 in the present invention are not particularly limited, and those skilled in the art can select them according to actual needs. For example, the cathode material can be at least one selected from Ti, Ni, Al, Pt, W, TiN and Au. Specifically, the cathode can be a Ti electrode, a Ni electrode, an Al electrode, a Pt electrode, a W electrode, a TiN electrode or an Au electrode, or a composite electrode composed of any of Ti, Ni, Al, Pt, W, TiN and Au. For another example, the anode material can be at least one selected from Ti, Ni, Au and Al. Specifically, the anode can be a Ti electrode, a Ni electrode, an Au electrode or an Al electrode, or a composite electrode composed of any of Ti, Ni, Au and Al. The selection of the above-mentioned cathode material and anode material in the present invention can further ensure that a good conductive path can be formed between the cathode and the anode, thereby ensuring the sensitivity of the detection.

[0045] According to some further specific embodiments of the present invention, the cathode 2 and anode 1 can be set to either forward bias or reverse bias, wherein the electric field direction of the forward bias is from the metal layer to the gallium nitride layer, and the electric field direction of the reverse bias is from the gallium nitride layer to the metal layer. The inventors have found that when the cathode and anode are set to forward bias, the detection sensitivity of the temperature sensor is better, while when the cathode and anode are set to reverse bias, the power required for detection is lower. The direction of the electric field can be adjusted according to the direction of the applied voltage.

[0046] Based on the same inventive concept as the gallium nitride temperature sensor, according to the second aspect of the present invention, the present invention proposes a method for preparing a gallium nitride temperature sensor. Figure 4 It is understood that the method includes: (1) forming a gallium nitride layer; (2) forming a tunneling layer on at least a portion of the surface of the gallium nitride layer and etching an electrode hole in the tunneling layer; (3) preparing an ohmic contact electrode in the electrode hole to form a cathode; (4) depositing a metal layer on a portion of the surface of the tunneling layer to form an anode. Compared with the existing technology, this method is not only simple in process, but also the gallium nitride temperature sensor produced adopts a new metal-tunneling layer-gallium nitride structure. It can detect and sense temperature by detecting the magnitude of the tunneling current based on the thermal tunneling effect. It has the advantages of high temperature resistance, high linearity and high sensitivity, and can better meet the temperature measurement requirements of high-power and high-temperature application scenarios.

[0047] According to some specific embodiments of the present invention, when a gallium nitride temperature sensor uses a substrate as a supporting layer, a gallium nitride layer can be formed on at least a portion of the substrate's surface. Furthermore, when a heterogeneous substrate is used as the supporting layer, a gallium nitride buffer layer can be pre-formed on at least a portion of the substrate's surface, and then the gallium nitride layer can be formed on at least a portion of the gallium nitride buffer layer. This ensures the overall strength of the sensor, the reliability, and the high sensitivity of the temperature sensor while reducing the thickness of the gallium nitride layer. It also improves the durability and service life of the temperature sensor while reducing raw material costs.

[0048] It should be noted that the method for preparing a gallium nitride temperature sensor in the present invention and the gallium nitride temperature sensor are proposed based on the same inventive concept. The features and effects described for the above-mentioned gallium nitride temperature sensor are also applicable to the method for preparing a gallium nitride temperature sensor, and will not be described in detail here.

[0049] According to the third aspect of the present invention, the present invention further proposes a method for measuring temperature using a gallium nitride temperature sensor. According to an embodiment of the present invention, the gallium nitride temperature sensor is the above-mentioned gallium nitride temperature sensor or is prepared using the above-mentioned method for preparing a gallium nitride temperature sensor, with reference to Figure 5 It is understood that the temperature measurement method includes: measuring the current value or voltage value between the cathode and anode of the GaN temperature sensor at different temperatures to obtain a current-temperature curve or voltage-temperature curve; directly or indirectly contacting the GaN temperature sensor with the device under test, measuring the current value or voltage value between the cathode and anode, and obtaining the temperature of the device under test based on the measured current value and current-temperature curve or based on the measured voltage value and voltage-temperature curve. The inventors have discovered that the crystallinity of the GaN layer, the thickness and material of the tunneling layer, and the materials of the cathode and anode can all affect the current-temperature curve or voltage-temperature curve. In other words, not all GaN temperature sensors have the same current-temperature curve. Therefore, before using the GaN temperature sensor for temperature measurement, it is necessary to pre-draw the current-temperature curve to ensure the reliability and accuracy of the test results. Furthermore, when using a GaN temperature sensor to measure the temperature of a device under test, the GaN temperature sensor can be placed directly in contact with the device under test or adjacent to it. Testing can be performed after the GaN temperature sensor has been in direct or indirect contact with the device under test for a predetermined period of time, or the current value can be recorded after the current between the cathode and anode of the GaN temperature sensor stabilizes. This further improves the accuracy and reliability of the test results. Compared to existing technologies, this temperature measurement method not only operates in high-temperature environments but is also adaptable to high-power applications, enabling better temperature measurement or monitoring of devices under test. It offers the advantages of high-temperature resistance, high linearity, high sensitivity, and high reliability.

[0050] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0051] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A gallium nitride temperature sensor, characterized in that: include: Gallium nitride layer; a tunneling layer, the tunneling layer being disposed on at least a portion of the surface of the gallium nitride layer, and the tunneling layer being provided with an electrode hole; a cathode disposed in the electrode hole and in contact with the gallium nitride layer; an anode, the anode being disposed on a portion of the surface of the tunneling layer, the anode not being in contact with the cathode, The tunneling layer material is at least one selected from silicon dioxide, hafnium oxide, aluminum oxide, titanium oxide, silicon nitride and aluminum nitride, The thickness of the tunneling layer is 0.5-10 nm.

2. The gallium nitride temperature sensor according to claim 1, characterized in that: The gallium nitride layer satisfies at least one of the following conditions: The thickness of the gallium nitride layer is 50 nm to 50 μm; The gallium nitride layer is an undoped gallium nitride layer, an n-type doped gallium nitride layer or a p-type doped gallium nitride layer; The gallium nitride layer is a single crystal layer.

3. The gallium nitride temperature sensor according to claim 1, characterized in that: The cathode material is at least one selected from Ti, Ni, Al, Pt, W, TiN and Au; and / or the anode material is at least one selected from Ti, Ni, Au and Al.

4. The gallium nitride temperature sensor according to any one of claims 1 to 3, characterized in that Further including: The gallium nitride layer is provided on at least a portion of a surface of the substrate.

5. The gallium nitride temperature sensor according to claim 4, characterized in that: Further including: A gallium nitride buffer layer is provided on at least a portion of the surface of the substrate, and the gallium nitride layer is provided on at least a portion of the surface of the gallium nitride buffer layer.

6. The gallium nitride temperature sensor according to claim 1 or 5, characterized in that: The cathode and the anode are set to be forward biased or reverse biased. The electric field direction of the forward bias is from the metal layer to the gallium nitride layer, and the electric field direction of the reverse bias is from the gallium nitride layer to the metal layer.

7. A method for preparing a gallium nitride temperature sensor, characterized in that: include: (1) forming a gallium nitride layer; (2) forming a tunneling layer on at least a portion of the surface of the gallium nitride layer, and etching an electrode hole in the tunneling layer; (3) preparing an ohmic contact electrode in the electrode hole to form a cathode; (4) depositing a metal layer on a portion of the surface of the tunneling layer to form an anode, The tunneling layer material is at least one selected from silicon dioxide, hafnium oxide, aluminum oxide, titanium oxide, silicon nitride and aluminum nitride.

8. The method according to claim 7, characterized in that In step (1), a gallium nitride layer is formed on at least a portion of the surface of the substrate; or, a gallium nitride buffer layer is formed on at least a portion of the surface of the substrate in advance, and then a gallium nitride layer is formed on at least a portion of the surface of the gallium nitride buffer layer.

9. A method for measuring temperature using a gallium nitride temperature sensor, characterized in that: The gallium nitride temperature sensor is the gallium nitride temperature sensor according to any one of claims 1 to 6 or is manufactured by the method for manufacturing a gallium nitride temperature sensor according to any one of claims 7 to 8, and the temperature measurement method includes: Test the current value or voltage value between the cathode and anode of the GaN temperature sensor at different temperatures to obtain a current-temperature curve or a voltage-temperature curve; The gallium nitride temperature sensor is directly or indirectly contacted with the device under test, and the current value or voltage value between the cathode and the anode is measured. The temperature of the device under test is obtained based on the measured current value and the current-temperature curve or based on the measured voltage value and the voltage-temperature curve.

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