Thermal imaging device and thermal imaging method

Abstract

The present application belongs to the field of semiconductor equipment technology, and particularly relates to a thermal imaging device and a thermal imaging method. The thermal imaging device is used to detect the surface temperature of a chip to be tested. The thermal imaging device includes a light source component for emitting light of a preset wavelength; a reflective component for reflecting the light emitted by the light source to a reflective layer on the surface of the chip to be tested; the reflective layer is arranged on the surface of the chip to be tested, and the bandgap width of the reflective layer is less than the energy of the light emitted by the light source; and an imaging component is used to receive the light reflected by the reflective layer and output an image of the surface of the chip to be tested. The thermal imaging device and the thermal imaging method provided by the present application use a reflective layer with a bandgap width less than the light energy of the light source component to reflect the surface temperature of the chip to be tested, which effectively solves the problem in the prior art that the thermal reflection imaging of the surface of the chip to be tested cannot be performed due to the excessively large bandgap of the chip to be tested, and meets the thermal reflection imaging temperature measurement requirements of the chip.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor equipment, and more specifically, to a thermal imaging device and a thermal imaging method. Background Art

[0002] Semiconductor chips are one of the core components of modern computing and are crucial to the realization of modern computing architectures, power electronics, rewritable media, and data storage and transmission. However, as the performance of these chips continues to improve, the feature scales that support the main functional elements (such as transistors, etc.) are getting smaller and smaller. Due to the physical limitations of chip size that have led to the failure of Moore's Law, chip self-heating is a key bottleneck problem that needs to be solved urgently. Effective thermal design and thermal management of chips requires knowing the temperature distribution and junction temperature of the chip first. The key to the problem is how to accurately measure the temperature of the chip, so effective microscopic thermal reflection imaging of the chip is a very important technology.

[0003] Although silicon-based chips are the mainstream of existing semiconductor chips, wide-bandgap and ultra-wide-bandgap semiconductors represented by gallium nitride (GaN), silicon carbide (SiC) and diamond are in the development stage from research and development to full application. Due to their wide bandgap and transparent to visible light, optical temperature measurement technology for traditional semiconductors such as silicon devices is extremely challenging. Currently, existing thermal reflection imaging devices generally use light in the visible light band for detection (such as the commonly used 532nm green light), but because the energy of such light is far less than the bandgap width of semiconductors such as gallium nitride (the bandgap width is about 3.2eV), such light is transparent to wide-bandgap chips and cannot be thermally reflected. It is urgent to develop new temperature measurement and microscopic thermal reflection imaging technology for wide-bandgap semiconductor devices. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a thermal imaging device and a thermal imaging method to solve the technical problem in the prior art that it is difficult for thermal imaging devices to perform thermal reflection imaging on wide bandgap chips.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is:

[0006] On the one hand, an embodiment of the present application provides a thermal imaging device for detecting the surface temperature of a chip to be tested, comprising:

[0007] A light source assembly, used for emitting light of a preset wavelength;

[0008] A reflective layer, disposed on the surface of the chip to be tested, and a bandgap width of the reflective layer is smaller than the energy of the light emitted by the light source;

[0009] A reflective component, used for reflecting the light emitted by the light source to the reflective layer on the surface of the chip to be tested;

[0010] An imaging component is used to receive the light reflected by the reflective layer and output an image of the surface of the chip to be tested.

[0011] Optionally, the reflective layer is a transition metal sulfide layer.

[0012] Optionally, the reflective layer is a molybdenum disulfide layer.

[0013] Optionally, the light source assembly includes a light source and a lens group for expanding and collimating light emitted by the light source.

[0014] Optionally, the light source is a visible light source, and / or the light source is an incoherent light source.

[0015] Optionally, the thermal imaging device further comprises a focusing lens located between the reflective component and the chip to be tested.

[0016] Optionally, the thermal imaging device further comprises an automatic focusing component for placing the chip to be tested and for automatic focusing.

[0017] A thermal imaging device provided in an embodiment of the present application has at least the following beneficial effects: Compared with the prior art, the thermal imaging device provided in an embodiment of the present application can be used to measure the surface temperature of a chip to be tested, and a light source component emits light of a preset wavelength, and at the same time, because the bandgap width of the reflective layer is smaller than the energy of the light, the reflective layer can reflect the light to the imaging component, and finally the imaging component outputs an image of the surface of the chip to be tested, thereby obtaining the temperature information of the surface of the chip to be tested. In this way, the surface temperature of the chip to be tested is reflected by the reflective layer on the surface of the chip to be tested, which effectively solves the problem of light directly passing through the chip to be tested due to the bandgap width of the material of the chip to be tested being greater than the light energy of the light source component, so that the thermal reflection imaging device can also perform thermal reflection imaging on wide bandgap chips.

[0018] On the other hand, the embodiment of the present application further provides a thermal imaging method, using the above-mentioned thermal imaging device, comprising the following steps:

[0019] A preparation step, preparing the reflective layer, and transferring the reflective layer to the surface of the chip to be tested;

[0020] In a calibration step, the light source component emits light to the chip to be tested at different temperatures, and the light is reflected to the imaging component via the reflective layer. The imaging component outputs images at different temperatures, and the thermal reflection coefficient of the reflective layer is obtained according to the gray value changes of the images at different temperatures.

[0021] The thermal imaging step is to place the chip to be tested into the thermal imaging device and power it on to obtain an image under current conditions, and obtain a temperature distribution image under current conditions based on the image information of the chip to be tested before power is supplied and the thermal reflection coefficient of the reflective layer.

[0022] Optionally, transition metal sulfide is grown on a substrate by chemical vapor deposition, and a single layer of transition metal sulfide is peeled off from the substrate to obtain the reflective layer.

[0023] Optionally, in the calibration step, the chip to be tested is heated to different temperatures by a heating component, and images of the chip to be tested at at least two different temperatures are acquired.

[0024] A thermal imaging method provided in an embodiment of the present application has at least the following beneficial effects: Compared with the prior art, the thermal imaging method provided in an embodiment of the present application uses the above-mentioned thermal imaging device to perform thermal reflection imaging on the chip to be tested, and uses a reflective layer whose bandgap width is smaller than the light energy of the light source component to reflect the surface temperature of the chip to be tested, which effectively solves the problem in the prior art that thermal reflection imaging of the chip to be tested cannot be performed due to the excessively large bandgap width of the chip to be tested, and meets the thermal reflection imaging temperature measurement requirements of the chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A schematic diagram of the structure of a thermal imaging device provided in an embodiment of the present application.

[0027] Among them, the reference numerals in the figure are:

[0028] 10. Light source assembly; 11. Light source; 12. Lens group; 20. Reflection assembly; 21. Reflector; 30. Imaging assembly; 40. Autofocus assembly; 50. Focusing mirror; 60. Chip to be tested; 61. Reflection layer. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0031] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0032] The various specific technical features and embodiments described in the specific implementation methods can be combined in any suitable manner unless there is any contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments / implementations. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features / embodiments / implementations in this application will not be described separately.

[0033] At present, existing thermal imaging devices generally use light in the visible light band for detection (such as the commonly used green light with a wavelength of 532nm), but because the energy of such light is much smaller than the bandgap width of semiconductors such as gallium nitride (the bandgap width is about 3.2eV), such light is transparent to wide bandgap chips and cannot perform thermal reflection imaging on their surfaces. Some existing thermal imaging devices use ultraviolet light sources for imaging, which requires various optical devices in the thermal imaging devices to have high ultraviolet light transmittance and imaging components with high quantum efficiency for ultraviolet light. In addition, considering that traditional semiconductor materials need to use visible light for thermal reflection imaging, it is necessary to switch light sources of different wavelengths and corresponding optical path components for devices based on different semiconductor materials, which greatly increases the complexity of equipment use and the cost of the device, making it difficult to promote and apply.

[0034] Therefore, the embodiments of the present application provide a thermal imaging device and a thermal imaging method, which can perform thermal reflection imaging on wide bandgap semiconductor chips and can also be applied to traditional semiconductor chips, so as to solve the technical problem in the prior art that thermal imaging devices are difficult to perform thermal reflection imaging on wide bandgap chips.

[0035] Please refer to Figure 1 The thermal imaging device provided in the embodiment of the present application includes a light source assembly 10, a reflective layer 61, a reflective assembly 20 and an imaging assembly 30. Specifically, when the imaging device of the present embodiment is used to detect the temperature of the surface of the chip 60 to be tested, the chip 60 to be tested can be placed on the detection station first, and the pre-prepared reflective layer 61 can be set on the surface of the chip. Then, the light source assembly 10 is used to emit a light of a preset wavelength, the energy of which is higher than the bandgap width of the reflective layer 61, and the light can be irradiated onto the reflective assembly 20, and the reflective assembly 20 reflects the light onto the reflective layer 61 on the surface of the chip 60 to be tested. After being reflected by the reflective layer 61, the light will be irradiated onto the imaging assembly 30, and the imaging assembly 30 is used to output an image of the surface of the chip 60 to be tested, thereby obtaining the temperature information of the surface of the chip 60 to be tested. Through such a design, the reflective layer 61 on the surface of the chip to be tested 60 is used to reflect the surface temperature of the chip to be tested 60, and because the bandgap width of the reflective layer 61 is smaller than the light energy of the light source 11, the reflective layer 61 will not be transparent to the light, and can effectively reflect the light to the imaging component 30. In this way, even if the bandgap width of the chip to be tested 60 is larger than the light energy of the light source 11, it will not affect the reflection and imaging of the light on the reflective layer 61 on the surface of the chip to be tested 60, which effectively solves the problem that the existing thermal imaging device is difficult to apply to the temperature measurement of wide bandgap chips. At the same time, when measuring the chips to be tested 60 with different bandgap widths, there is no need to replace the light source 11 lamp device in the thermal imaging device, which effectively reduces the complexity and device cost of the thermal imaging device, and has the characteristics of simple structure and convenient operation.

[0036] As one of the optional implementations of this embodiment, the reflective layer 61 can be a transition metal sulfide layer. Specifically, the bandgap width of the two-dimensional layered material of the transition metal sulfide is generally about 1.5 eV, and its bandgap energy is lower than the light energy of the commonly used light source component 10, such as the commonly used green light with a wavelength of 532 nm, and the transition metal sulfide will not interfere with the electrical performance of the chip to be tested 60, ensuring the normal operation of the chip to be tested 60. In this way, the light of the light source component 10 can be reflected by the reflective layer 61 on the chip surface, so as to obtain the temperature data of the surface of the chip to be tested 60.

[0037] Specifically, as one of the optional implementations of this embodiment, the reflective layer 61 can be a molybdenum disulfide layer. Of course, the reflective layer 61 can also be made of other suitable materials, such as tungsten disulfide, etc. In specific applications, the reflective layer 61 can be a single-layer molybdenum disulfide layer, and its thickness can be in the nanometer scale. In this way, when the reflective layer 61 is transferred to the surface of the chip to be tested 60, the extremely thin reflective layer 61 can be closely attached to the surface of the chip to be tested, so that the reflective layer 61 can effectively reflect the surface temperature of the chip to be tested 60, thereby improving the accuracy of detection.

[0038] As an optional implementation of this embodiment, please refer to Figure 1 The light source assembly 10 includes a light source 11 and a lens group 12. The lens group 12 can be located between the light source 11 and the reflective assembly 20. The light emitted by the light source 11 can first pass through the lens group 12 and then irradiate the reflective assembly 20. In this way, the lens group 12 can be used to expand and collimate the light of the light source 11, which is beneficial to improve the accuracy of the thermal imaging device.

[0039] Specifically, as one of the optional implementations of this embodiment, the light source 11 can be a visible light source. Specifically, the light source 11 can emit light within the visible light band, such as a green LED (Light-Emitting Diode) light source with a wavelength of 532nm. In this way, optical components such as the lens group 12, the reflective component 20 and the imaging device in the thermal imaging device can be selected from optical components in existing visible light thermal imaging devices, without the need for high transmittance to ultraviolet light, so as to reduce the cost of the thermal imaging device. At the same time, it is also convenient for the thermal imaging device to measure traditional semiconductor chips without replacing various components, thereby improving the practicality of the thermal imaging device.

[0040] In specific applications, the chip to be tested 60 detected by this embodiment can be a gallium nitride chip, a silicon carbide chip, a zinc oxide chip or a diamond chip. Such semiconductor chips have a wide bandgap width, are transparent to general visible light, and cannot be effectively imaged using visible light. The reflective layer 61 of this embodiment can reflect the surface temperature of such semiconductor chips, and is opaque to visible light, and can be imaged on the imaging component 30. Of course, the chip to be tested 60 detected by this embodiment can be a traditional semiconductor chip, such as a silicon-based chip, a germanium-based chip, etc., and in the case of such a chip to be tested 60, a reflective layer 61 may be provided on its surface, or the reflective layer 61 may not be provided.

[0041] Specifically, as one of the optional implementations of this embodiment, the light source 11 can be an incoherent light source. The light emitted by the light source 11 is incoherent, which can reduce the interference effect of the reflective layer 61 on the light and improve the measurement accuracy of the thermal imaging device.

[0042] As an optional implementation of this embodiment, please refer to Figure 1 The thermal imaging device also includes a focusing mirror 50, which can be arranged between the reflective component 20 and the chip to be tested 60. The focusing mirror 50 can focus the light reflected by the reflective component 20 onto the reflective layer 61 on the surface of the chip to be tested 60, which is beneficial to improving the accuracy of thermal imaging.

[0043] As an optional implementation of this embodiment, please refer to Figure 1 The thermal imaging device also includes an automatic focusing component 40. In a specific application, when detecting the chip to be tested 60, the chip to be tested 60 can be placed on the automatic focusing component 40. The automatic focusing component 40 can adjust the relative position of the chip to be tested 60 and the imaging component 30. Specifically, the automatic focusing component 40 can move the chip to be tested 60 in the horizontal direction or the vertical direction, so that the surface of the chip to be tested 60 can be located at the focus of the imaging component 30, thereby obtaining a clear image. In addition, when the chip to be tested 60 is powered on and generates heat, the chip to be tested 60 may expand. The automatic focusing component 40 can adjust the position of the chip to be tested 60 so that the imaging component 30 can obtain a clear image. Correspondingly, when the chip to be tested 60 cools down and recovers, it can also be adjusted through the automatic focusing component 40 to ensure the clarity of the image output by the imaging component 30.

[0044] As an optional implementation of this embodiment, please refer to Figure 1 , the reflection component 20 includes a reflection mirror 21. Specifically, the reflection mirror 21 can be a beam splitter, which can be tilted. The light source 11 and the chip to be tested 60 can be vertically arranged (vertical means that the light from the light source 11 irradiating the beam splitter is perpendicular to the light reflected by the beam splitter to the chip to be tested 60), and the chip to be tested 60 can be arranged opposite to the imaging component 30. In this way, when the light from the light source 11 irradiates the beam splitter, the beam splitter can reflect the light to the reflection layer 61 of the chip to be tested 60, and after being reflected by the reflection layer 61, it can pass through the beam splitter and fall on the imaging component 30. Of course, in other embodiments, the relative positions of the light source component 10, the chip to be tested 60, the imaging component 30 and the reflection component 20 can be reasonably adjusted according to actual conditions, and this embodiment is not limited thereto.

[0045] As one of the optional implementations of this embodiment, the imaging component 30 may be an area array camera. When the light reflected by the reflective layer 61 is irradiated onto the area array camera, the area array camera may output a corresponding image. In specific applications, the area array camera may be a CCD (Charge-coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera.

[0046] A thermal imaging device provided in the embodiment of the present application has at least the following beneficial effects: Compared with the prior art, the thermal imaging device provided in the embodiment of the present application can be used to measure the surface temperature of the chip to be tested 60, and the light source assembly 10 emits light of a preset wavelength, and the light is reflected to the reflective layer 61 on the surface of the chip to be tested 60 via the reflective assembly 20, and the surface temperature of the chip to be tested 60 is reflected by the reflective layer 61. At the same time, since the bandgap width of the reflective layer 61 is smaller than the energy of the light, the reflective layer 61 can reflect the light to the imaging assembly 30, and finally the imaging assembly 30 outputs the image of the surface of the chip to be tested 60, thereby obtaining the temperature information of the surface of the chip to be tested 60. In this way, the surface temperature of the chip to be tested 60 is reflected by the reflective layer 61 on the surface of the chip to be tested 60, which effectively solves the problem that the light directly passes through the chip to be tested 60 due to the bandgap width of the chip to be tested 60 being greater than the light energy of the light source assembly 10, so that the thermal imaging device can also perform thermal reflection imaging on wide bandgap chips.

[0047] The present application also provides a thermal imaging method, which uses the thermal imaging device described above and includes the following steps:

[0048] Preparation step, preparing the reflective layer 61, and transferring the reflective layer 61 to the surface of the chip to be tested 60;

[0049] In the calibration step, the light source assembly 10 emits light to the chip 60 to be tested at different temperatures. The light is reflected to the imaging assembly 30 via the reflective layer 61. The imaging assembly 30 outputs images at different temperatures. The thermal reflection coefficient of the reflective layer 61 is obtained according to the gray value changes of the images at different temperatures.

[0050] In the thermal imaging step, the chip to be tested 60 is placed in a thermal imaging device to obtain an image under current conditions, and a temperature distribution image under current conditions is obtained according to the thermal reflection coefficient of the reflective layer 61 .

[0051] In specific applications, a suitable material of the reflective layer 61 can be selected according to the specific type of the chip to be tested 60. Taking gallium nitride chips as an example, since the bandgap width of gallium nitride is relatively wide, visible light is transparent to such chips, so a reflective layer 61 with a relatively narrow bandgap width can be prepared in advance. After the reflective layer 61 is prepared, the reflective layer 61 can be transferred to the surface of the chip to be tested 60, and the chip to be tested 60 is placed on the automatic focusing component 40, and the position of the chip to be tested 60 is adjusted by the automatic focusing component 40 at room temperature (for example, 25 degrees Celsius). At this time, the chip to be tested 60 is in an unpowered state, the light source component 10 emits light, which is reflected to the chip to be tested 60 through the reflection component 20, and the reflective layer 61 on the surface of the chip to be tested 60 reflects the light to the imaging component 30, and the imaging component 30 outputs an image of the chip to be tested 60 in the unpowered state. Then, the chip to be tested 60 is heated, and the real-time temperature of the chip to be tested 60 on the temperature measuring component side is measured, and the position of the chip to be tested 60 is adjusted by the automatic focusing component 40, so that the imaging component 30 outputs an image at the current temperature. Finally, according to the change in the grayscale value of the image before and after heating, the thermal reflection coefficient of the reflective layer 61 (i.e., the correspondence between the grayscale value of the image and the temperature) is obtained, and a more accurate thermal reflection coefficient can be obtained by acquiring images and temperatures multiple times under different conditions to reduce errors.

[0052] Then, under different conditions, the chip to be tested 60 provided with the reflective layer 61 can be powered on, so that the chip to be tested 60 can run and self-heat, the position of the chip to be tested 60 can be adjusted and the corresponding image can be output, and then the temperature distribution under the current conditions can be obtained according to the image information before the chip to be tested 60 is powered on and the thermal reflection coefficient obtained in the calibration step, and the final thermal image of the chip to be tested 60 can be rendered in different colors through software. In this way, after obtaining the thermal reflection coefficient of the reflective layer 61, the temperature distribution image of the chip to be tested 60 can be directly obtained according to the image output by the imaging component 30, which effectively solves the problem of difficulty in thermal reflection imaging of wide-band chips in the prior art and reduces the imaging cost.

[0053] As one of the optional implementations of this embodiment, in the calibration step, the corresponding relationship between the image of the chip to be tested 60 and the temperature can be obtained under at least two sets of different temperature conditions to obtain the thermal reflection coefficient of the reflective layer 61. The two sets of different conditions can be the chip to be tested at room temperature and the chip to be tested heated to a preset temperature by a heating component (such as a heating table), or the chip to be tested can be heated to two different preset temperatures by a heating component. In order to improve the accuracy of the thermal reflection coefficient, the corresponding relationship between the image of the chip to be tested 60 and the temperature under multiple sets of different conditions can be obtained to reduce the error of the thermal reflection coefficient. In addition, in order to further improve the accuracy of the thermal reflection coefficient, each time imaging is performed at a preset temperature, multiple imaging can be performed at the temperature to reduce the noise error of the imaging component 30.

[0054] As one of the optional implementations of this embodiment, in the step of preparing the reflective layer 61 , a single layer of transition metal sulfide can be grown on the substrate by chemical vapor deposition, and the single layer of transition metal sulfide can be peeled off from the substrate to obtain the reflective layer 61 .

[0055] In specific applications, a suitable material for the reflective layer 61 can be selected according to the type of the chip 60 to be tested and the type of the light source assembly 10. For example, taking the reflective layer 61 as a molybdenum disulfide layer as an example, Mo(CO)6 (diluted to 15torr in nitrogen) can be used as a metal precursor for the growth of molybdenum disulfide, (C2H5)2S as a sulfur source at room temperature, nitrogen and hydrogen as carrier gases, a growth temperature of 525 degrees Celsius, a growth time of 15h to 20h, and organic chemical vapor deposition is used to grow a large area of ​​molybdenum disulfide on a SiO2 / Si substrate in a hot wall tube furnace. Then, PMMA (polymethyl methacrylate, 495K, diluted with 4% anisole) can be spin-coated on the molybdenum disulfide, the rotation speed can be 2800rpm, the spin coating time can be 60s, and baked at 180 degrees Celsius for about 3min. Then, a polymer adhesive film can be spin-coated on the thermal release tape, the thermal release tape can be pressed onto the substrate, and the molybdenum disulfide layer can be peeled off from the substrate. Then, according to the thickness of the molybdenum disulfide layer, the peeling step can be repeated under vacuum until the desired molybdenum disulfide reflective layer 61 is obtained, and finally the prepared molybdenum disulfide is released and transferred to the surface of the chip to be tested 60. Of course, in other embodiments, according to the different materials of the reflective layer 61, a suitable preparation method can be selected, and this embodiment is not limited thereto, for example, W(CO)6 is selected as the metal precursor for the growth of the tungsten disulfide reflective layer 61.

[0056] A thermal imaging method provided in an embodiment of the present application has at least the following beneficial effects: compared with the prior art, the thermal imaging method provided in the embodiment of the present application uses the above-mentioned thermal imaging device to perform thermal reflection imaging on the chip to be tested 60, and uses the reflective layer 61 whose bandgap width is smaller than the light energy of the light source assembly 10 to reflect the surface temperature of the chip to be tested 60, which effectively solves the problem in the prior art that thermal reflection imaging of the chip to be tested 60 cannot be performed due to the excessively large bandgap width of the chip to be tested 60, and meets the thermal reflection imaging temperature measurement requirements of the chip.

[0057] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A thermal imaging device for detecting the surface temperature of a chip to be tested, characterized in that: include: A light source assembly, used to emit light of a preset wavelength, wherein the light source is a visible light source; A reflective layer is disposed on the surface of the chip to be tested, and the bandgap width of the reflective layer is smaller than the energy of the light emitted by the light source; the reflective layer is a transition metal sulfide layer; A reflective component, used for reflecting the light emitted by the light source to the reflective layer on the surface of the chip to be tested; An imaging component, used for receiving the light reflected by the reflective layer and outputting an image of the surface of the chip to be tested; The chip to be tested is a gallium nitride chip, a silicon carbide chip, a zinc oxide chip or a diamond chip.

2. The thermal imaging device according to claim 1, characterized in that: The reflective layer is a molybdenum disulfide layer.

3. The thermal imaging device according to claim 1, characterized in that: The light source assembly comprises a light source and a lens group for expanding and collimating the light emitted by the light source.

4. The thermal imaging device according to claim 3, characterized in that: The light source is an incoherent light source.

5. The thermal imaging device according to any one of claims 1 to 4, characterized in that: The thermal imaging device also includes a focusing lens located between the reflection component and the chip to be tested.

6. The thermal imaging device according to any one of claims 1 to 4, characterized in that: The thermal imaging device also includes an automatic focusing component for placing the chip to be tested and for automatic focusing.

7. A thermal imaging method, characterized in that: The thermal imaging device according to any one of claims 1 to 6 comprises the following steps: A preparation step, preparing the reflective layer, and transferring the reflective layer to the surface of the chip to be tested; In a calibration step, the light source component emits light to the chip to be tested at different temperatures, and the light is reflected to the imaging component via the reflective layer. The imaging component outputs images at different temperatures, and the thermal reflection coefficient of the reflective layer is obtained according to the gray value changes of the images at different temperatures. The thermal imaging step is to place the chip to be tested into the thermal imaging device and power it on to obtain an image under current conditions, and obtain a temperature distribution image under current conditions based on the thermal reflection coefficient of the reflective layer according to the image information of the chip to be tested before power is turned on.

8. The thermal imaging method according to claim 7, characterized in that: Transition metal sulfide is grown on a substrate by chemical vapor deposition, and a single layer of transition metal sulfide is peeled off from the substrate to obtain the reflective layer.

9. The thermal imaging method according to claim 8, characterized in that: In the calibration step, the chip to be tested is heated to different temperatures by a heating component, and images of the chip to be tested at at least two different temperatures are obtained.

Images