Methods and apparatus for measuring the thermophysical properties of heterojunctions based on thermal imaging

Abstract

This invention provides a method and apparatus for measuring the thermophysical properties of heterojunctions based on thermal imaging, comprising: obtaining the thermal conductivity of the substrate of the heterojunction sample under test based on the first discrete point of change within a first test duration using finite element simulation calculations; obtaining the specific heat of the substrate based on the first discrete point of change within a second test duration and the thermal conductivity of the substrate using finite element simulation calculations; obtaining the interfacial thermal resistance and specific heat of the thin film of the heterojunction sample under test based on the second discrete point of change within a third test duration and the thermal conductivity and specific heat of the substrate using finite element simulation calculations; and obtaining the thermal conductivity of the thin film based on the third discrete point of change within a fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate using finite element simulation calculations. This invention enables simultaneous measurement of multiple parameters, improving measurement efficiency, and improves measurement accuracy by utilizing finite element simulation calculations.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a method and apparatus for measuring the thermophysical properties of heterojunctions based on thermal imaging. Background Technology

[0002] Solid-state heterostructures, also known as heterojunctions, are generally composed of a substrate and an epitaxial thin film. The constituent materials include metals, semiconductors, or insulators, and they are widely used in various advanced technology fields such as power electronics, radio frequency communication, photovoltaics, and thermoelectrics.

[0003] However, with the rapid iteration of device performance indicators, heat generation and junction temperature have also increased dramatically. This requires devices to possess good thermal conductivity while maintaining high electron mobility, high breakdown field strength, and high power. To enhance the thermal conductivity of heterojunction devices, researchers have conducted extensive thermal analysis and optimization designs from the near-junction region of heterostructure devices to external heat dissipation structures. However, these efforts still cannot fully meet the increasingly stringent and complex thermal management requirements. One important reason for this is the current lack of truly efficient methods suitable for measuring the thermophysical properties of various heterojunctions.

[0004] In the existing technology, the experimental methods that can be used to measure the thermophysical properties of heterojunctions mainly include time-domain thermal reflectometry, Raman spectroscopy, and 3ω electrical methods.

[0005] Among them, the time-domain thermal reflectometry (TDRT) method uses a beam splitter to divide a picosecond or femtosecond laser into a pump beam and a probe beam. By fitting the relationship between the reflected probe beam signal and the time delay or modulation frequency, parameters such as the thermal conductivity and specific heat of the thin film and substrate of the heterostructure sample under test, as well as the interfacial thermal resistance between them, are derived. Because the laser repetition frequency of this type of method is on the order of 10 MHz, the corresponding thermal penetration depth is very shallow (~100 nm). Therefore, its signal has low sensitivity to the interfacial thermal resistance and substrate thermal conductivity of widely used micron-scale thin film heterostructures, resulting in large measurement uncertainty. Raman spectroscopy is used to detect the surface temperature of specific materials. Incident photons undergo inelastic scattering with atoms, resulting in energy exchange and the generation of a Raman signal. Changes in material temperature cause changes in polarizability, thereby altering the Raman signal. Based on this principle, the internal temperature distribution of a sample can be determined, and the thermal conductivity and interfacial thermal resistance of the thin film and substrate of heterostructures can be derived. The measurement uncertainty of this method is approximately 5 K, and the normal temperature spatial resolution is typically greater than 1 μm. These characteristics severely limit the measurement accuracy of this method. For the 3ω electrical method, a strip-shaped metal thin film needs to be prepared on the sample surface as both a heating electrode and a detection electrode. Alternating current heating is applied, and the 3ω and 2ω voltage signals of the electrodes are extracted to derive the relevant thermophysical properties. However, this method requires precise design of the electrode dimensions to achieve high sensitivity, and it is insensitive to the specific heat of the material at lower frequencies.

[0006] In summary, existing methods for measuring the thermophysical properties of heterojunctions suffer from low measurement accuracy and efficiency. Summary of the Invention

[0007] This invention provides a method for measuring the thermophysical properties of heterojunctions based on thermal imaging, which solves the problem of low efficiency in the measurement of thermophysical properties of heterojunctions in the prior art, and achieves high efficiency and high accuracy in measuring the specific heat, thermal conductivity and interfacial thermal resistance of thin films and substrates of heterojunction samples.

[0008] This invention provides a method for measuring the thermophysical properties of heterojunctions based on thermal imaging, comprising:

[0009] During the test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample to be tested are obtained to obtain the first discrete points of the first average temperature rise value changing with time during the test duration;

[0010] Based on finite element simulation calculations, the thermal conductivity of the substrate of the heterojunction sample under test is obtained according to the discrete points of the first change within the first test duration.

[0011] Based on finite element simulation calculations, the specific heat of the substrate is obtained according to the discrete points of the first change within the second test duration and the thermal conductivity of the substrate;

[0012] Within the test duration, multiple second-average temperature rise values ​​of the second target region and multiple third-average temperature rise values ​​of the third target region of the heterojunction sample under test are obtained to obtain the second variation discrete points of the second-average temperature rise value as a function of time within the test duration, and the third variation discrete points of the third-average temperature rise value as a function of time within the test duration.

[0013] Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate.

[0014] Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained by considering the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate.

[0015] The first average temperature rise value, the second average temperature rise value, and the third average temperature rise value are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method.

[0016] According to a method for measuring the thermophysical properties of a heterojunction based on thermal imaging provided by the present invention, within a test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test are acquired to obtain the first discrete points of the first average temperature rise value changing with time within the first test duration. This method further includes:

[0017] A heating electrode is disposed on at least a portion of the surface of the thin film of the heterojunction sample to be tested, wherein the heating electrode has a predetermined width;

[0018] A pulsed square wave heating current with preset parameters is applied to the heating electrode;

[0019] The pulse width of the pulse current is Δt. a .

[0020] According to the present invention, a method for measuring the thermophysical properties of a heterojunction based on thermal imaging is provided. Based on finite element simulation calculations, the thermal conductivity of the substrate of the heterojunction sample under test is obtained according to the first discrete point of change within a first test duration. Specifically, the method includes:

[0021] After the pulse begins, Δt a ~2Δt a The time range is defined as the first test duration. Within the first test duration, the thermal conductivity k of the substrate is obtained through univariate inversion based on finite element simulation and the first discrete point of change. sub .

[0022] According to the present invention, a method for measuring the thermophysical properties of a heterojunction based on thermal imaging is provided. Based on finite element simulation calculations, the specific heat of the substrate is obtained according to the discrete point of the first change within a second test duration and the thermal conductivity of the substrate. Specifically, the method includes:

[0023] From 0 to Δt after the pulse begins a The time range is used as the second test duration. Based on finite element simulation, the specific heat of the substrate is obtained through univariate inversion according to the discrete points of the first variation and the thermal conductivity of the substrate.

[0024] According to the present invention, a method for measuring the thermophysical properties of a heterojunction based on thermal imaging acquires multiple second-level average temperature rise values ​​of a second-level target region and multiple third-level average temperature rise values ​​of a third-level target region of the heterojunction sample under test, so as to obtain the second-level variation discrete points of the second-level average temperature rise value changing with time during the test duration and the third-level variation discrete points of the third-level average temperature rise value changing with time during the test duration, further comprising:

[0025] A pulsed square wave heating current with preset parameters is applied to the heating electrode;

[0026] The pulse width of the pulse current is Δt. b .

[0027] According to the present invention, a method for measuring the thermophysical properties of heterojunctions based on thermal imaging is provided. Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained from the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Specifically, the method includes:

[0028] From 0 to 2Δt after the pulse begins b The time range is defined as the third test duration. Within the third test duration, based on finite element simulation, the specific heat of the thin film is obtained by least squares inversion using the least squares method according to the discrete points of the second variation and the thermal conductivity and specific heat of the substrate. and the interfacial thermal resistance R between the substrate and the thin film I .

[0029] According to the present invention, a method for measuring the thermophysical properties of a heterojunction based on thermal imaging is provided. Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained according to the discrete points of the third variation within the fourth test duration, the interface thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. Specifically, this includes:

[0030] From 0 to Δt after the pulse begins b The time range is used as the fourth test duration. Based on finite element simulation, the thermal conductivity k of the thin film is obtained by univariate inversion based on the discrete points of the third variation and the interface thermal resistance, the specific heat of the thin film, and the thermal conductivity of the substrate. f .

[0031] The present invention also provides a device for measuring the thermophysical properties of heterojunctions based on thermal imaging, comprising:

[0032] The first test module is used to acquire multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test within the test duration, so as to obtain the first discrete point of the first average temperature rise value changing with time within the test duration;

[0033] The first calculation module is used to calculate the thermal conductivity of the substrate of the heterojunction sample under test based on the first discrete point of change within the first test duration, and to calculate the specific heat of the substrate based on the first discrete point of change within the second test duration and the thermal conductivity of the substrate, based on the finite element simulation.

[0034] The second testing module is used to acquire multiple second average temperature rise values ​​of the second target region and multiple third average temperature rise values ​​of the third target region of the heterojunction sample under test within the test duration, so as to obtain the second variation discrete points of the second average temperature rise value changing with time within the test duration and the third variation discrete points of the third average temperature rise value changing with time within the test duration.

[0035] The second calculation module is used to calculate the interfacial thermal resistance and specific heat of the heterojunction sample under test based on finite element simulation, according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate; and to calculate the thermal conductivity of the thin film based on the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate.

[0036] The first average temperature rise value, the second average temperature rise value, and the third average temperature rise value are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method.

[0037] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement any of the above-described methods for measuring the thermophysical properties of heterojunctions based on thermal imaging.

[0038] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the heterojunction thermophysical property measurement method based on thermal imaging as described above.

[0039] The present invention provides a method and apparatus for measuring the thermophysical properties of heterojunctions based on thermal imaging. This method acquires multiple first-average temperature rise values ​​of a first target region of a heterojunction sample under test within a test duration, thereby obtaining first-discrete points of the first-average temperature rise value changing with time within the test duration. Based on finite element simulation calculations, the thermal conductivity of the substrate of the heterojunction sample under test is obtained based on the first-discrete points of the first-average temperature rise value within a first test duration. Based on finite element simulation calculations, the specific heat of the substrate is obtained based on the first-discrete points of the first-average temperature rise value within a second test duration and the thermal conductivity of the substrate. Within the test duration, multiple second-average temperature rise values ​​of a second target region and multiple third-average temperature rise values ​​of a third target region of the heterojunction sample under test are acquired to obtain the... The second average temperature rise value is defined as the discrete point of the second variation over time within the test duration, and the third average temperature rise value is defined as the discrete point of the third variation over time within the test duration. Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained based on the discrete point of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained based on the discrete point of the third variation within the fourth test duration and the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. The first, second, and third average temperature rise values ​​are obtained by measuring the surface of the heterojunction sample under test using thermal imaging. This invention sets a heating electrode on the surface of the thin film away from the substrate, uses thermal imaging to test the temperature rise changes of different regions of the sample surface at different times, and combines finite element simulation calculations to obtain the required parameters, resulting in high accuracy in parameter measurement. Furthermore, the method provided by this invention enables simultaneous measurement of multiple parameters, avoiding the use of multi-parameter fitting algorithms, facilitating solution, and improving measurement efficiency. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating the method for measuring the thermophysical properties of heterojunctions based on thermal imaging provided by the present invention.

[0042] Figure 2 This is a schematic diagram of a test sample structure cross-section according to an embodiment of the method for measuring the thermophysical properties of heterojunctions based on thermal imaging provided by the present invention.

[0043] Figure 3This is a top view of the test sample structure and test area of ​​an embodiment of the heterojunction thermophysical property measurement method based on thermal imaging provided by the present invention.

[0044] Figure 4 This is a schematic diagram of the pulsed square wave heating current in the heterojunction thermophysical property measurement method based on thermal imaging provided by the present invention.

[0045] Figure 5 This is a schematic diagram of the structure of the heterojunction thermophysical property measurement device based on thermal imaging provided by the present invention;

[0046] Figure 6 This is a schematic diagram of the physical structure of an electronic device provided by the present invention.

[0047] Figure label:

[0048] 510: First test module; 520: First calculation module; 530: Second test module; 540: Second calculation module;

[0049] 610: Processor; 620: Communication interface; 630: Memory; 640: Communication bus. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0051] The following is combined Figures 1-6 This invention describes a method and apparatus for measuring the thermophysical properties of heterojunctions based on thermal imaging.

[0052] In principle, thermal reflection imaging utilizes the functional relationship between a material's reflectivity and temperature. It derives the temperature coefficient of reflectivity based on the change in reflectivity per unit temperature change, and then obtains the temperature change by measuring the change in the intensity of reflected light on the surface of the device under test. An LED light source provides stable incident light to the surface of the device under test, while a charge-coupled device (CCD) detects the intensity of reflected light as a function of temperature. Thermal reflection imaging boasts high spatial resolution (<300 nm) and high temporal resolution (~50 ns), and can image a wide range of materials, including metals and semiconductors commonly used in electronic devices.

[0053] Infrared thermal imaging utilizes the principle of infrared radiation. Any object with a finite temperature can radiate electromagnetic waves, the intensity of which depends on its temperature and emissivity. Infrared thermometers collect electromagnetic waves of infrared wavelengths, and the temperature of the sample can be extracted according to Planck's law of blackbody radiation. To map the temperature distribution on the sample surface, an infrared array detector is used in an infrared microscope. Each pixel converts infrared radiation into a change in the resistance of a single pixel, which is then transformed into a two-dimensional temperature distribution. This technique is a non-contact, non-destructive, and convenient method with extremely fast imaging capabilities. Its temperature resolution can be described by the noise equivalent temperature difference (NETD), which determines the minimum temperature difference that can be detected. The NETD of infrared thermometry can now reach the mK level.

[0054] Therefore, both reflective thermal imaging and infrared thermal imaging methods can perform integrated temperature testing of heterostructure samples in two dimensions and one dimension in one time. They can be used to simultaneously measure the specific heat, thermal conductivity, and interfacial thermal resistance of the thin film and substrate of heterojunction samples, thereby improving the efficiency and accuracy of characterization.

[0055] Figure 1 This is a flowchart illustrating the method for measuring the thermophysical properties of heterojunctions based on thermal imaging provided by the present invention. Figure 1 As shown, the method includes the following steps:

[0056] Step 110: During the test duration, obtain multiple first average temperature rise values ​​of the first target region of the heterojunction sample to be tested, so as to obtain the first discrete point of the first average temperature rise value changing with time during the test duration.

[0057] like Figure 2 As shown, the heterojunction sample structure to be tested includes an insulating layer 201, a thin film 202, an interface 203, and a substrate 204. In one embodiment of the present invention, the material of the insulating layer is not particularly limited. Specifically, the insulating layer is selected from at least one of silicon dioxide, hafnium dioxide, zirconium dioxide, aluminum oxide, gallium oxide, and silicon nitride. Those skilled in the art can select the method in this application to test the thermal conductivity and specific heat of the insulating layer of the sample according to actual needs.

[0058] The material of the thin film must be limited to a hard solid material with a bandgap of less than or equal to 3.40 eV. Specifically, the thin film can be gallium nitride thin film, gallium arsenide thin film, silicon thin film, germanium thin film, molybdenum disulfide thin film, silicon carbide thin film, gallium arsenide thin film, indium gallium arsenide thin film, indium arsenide thin film, aluminum gallium arsenide thin film, aluminum arsenide thin film, gallium phosphide thin film, indium gallium phosphide thin film, indium phosphide thin film, zinc oxide thin film, zinc telluride thin film, or titanium dioxide thin film, etc. According to some embodiments of the present invention, the thickness of the thin film is not particularly limited; for example, the thickness of the thin film can be 50 nm to 20 μm. This avoids the thin film being too thick, which would affect the sensitivity of temperature rise changes to the specific heat, thermal conductivity, and interfacial thermal resistance of the substrate.

[0059] The substrate material is not particularly limited; any hard solid material can be tested using the above method. Specifically, in this invention, the substrate material includes at least one of the following: non-radioactive inorganic non-metallic solid materials, non-radioactive inorganic metallic solid materials, non-radioactive organic non-metallic solid materials, and non-radioactive organic metallic solid materials. Specifically, the substrate is selected from at least one of gallium nitride, aluminum gallium nitride, aluminum nitride, tantalum nitride, gallium oxide, aluminum gallium oxide, aluminum oxide, sapphire, silicon, germanium, silicon-germanium alloy, silicon dioxide, quartz, silicon carbide, silicon nitride, diamond, graphite, highly oriented pyrolytic graphite, boron arsenide, gallium arsenide, indium gallium arsenide, indium arsenide, aluminum gallium arsenide, aluminum arsenide, gallium phosphide, indium gallium phosphide, zinc oxide, hafnium dioxide, titanium dioxide, titanium nitride, magnesium oxide, lithium niobate, strontium titanate, strontium ruthenate, and mica, and their composite materials. According to some embodiments of the present invention, the thickness of the substrate is not particularly limited; for example, the thickness of the substrate can be 10 μm to 1 cm. This avoids the substrate being too thin, thus preventing breakage during testing.

[0060] During operation, a heating electrode 205 with a width of W is first disposed on at least a portion of the surface of the thin film 202 away from the substrate 204. h Structural reference Figure 2 and Figure 3 Then, a pulsed square wave heating current with an amplitude of I is applied to the heating electrode. a Its pulse width is Δt a , Δt a The duration of the first pulse is d, and its duty cycle is d. a Pulse waveform reference Figure 4 Using thermal imaging, the first average temperature rise ΔT1 of region I on the sample surface at a certain position in the width direction of the heating electrode is measured, and the discrete points of ΔT1 change over time are obtained, namely the first discrete points of change.

[0061] Region I is defined as a distance l1 to l1+Δl1 from the heating electrode. The distance parameter l1 can be 3μm to 8μm, and Δl1 can be 2μm to 7μm.

[0062] The amplitude I of the pulsed square wave heating current a It can be 50mA to 500mA, with a pulse width Δt. a The duty cycle can be from 200 ns to 50 μs, with a duty cycle d. a It can be 0.5% to 10%.

[0063] Thermal imaging methods include reflection thermal imaging and infrared thermal imaging.

[0064] In some embodiments of the present invention, in the reflection thermal imaging method, a wavelength of λ is selected. a LED light source, light source wavelength λ a The wavelength range can be 340nm to 780nm, specifically 340nm, 365nm, 405nm, 455nm, 470nm, 505nm, 530nm, 625nm, 656nm, 780nm, etc. The actual selection can be based on the material's temperature coefficient of reflectance (C) at that wavelength. th Choose the corresponding higher C. th The absolute wavelength can be determined by consulting literature or through actual calibration. The reflected thermal light source and the heterojunction sample under test are at a preset distance.

[0065] In some embodiments of the present invention, in the infrared thermal imaging method, the infrared radiation band detected by the infrared array detector can be mid-wave infrared (wavelength range of 3 to 5 μm) or long-wave infrared (wavelength range of 7.5 to 13.5 μm).

[0066] Step 120: Based on finite element simulation calculation, obtain the thermal conductivity of the substrate of the heterojunction sample under test according to the discrete points of the first change within the first test duration.

[0067] After obtaining the first discrete point of change within the first test duration, the thermal conductivity of the substrate of the heterojunction sample under test is obtained based on finite element simulation calculation. It is important to note that finite element simulation refers to constructing a model in a computer with the same structure as the actual sample, setting the same heat flow and temperature boundary conditions, simulating the real situation of the sample under test, and thus calculating the corresponding thermophysical parameters.

[0068] Step 130: Based on finite element simulation calculation, obtain the specific heat of the substrate according to the discrete point of the first change within the second test duration and the thermal conductivity of the substrate.

[0069] In actual operation, after obtaining the thermal conductivity of the first discrete point of change and the substrate during the second test period, the specific heat of the substrate is obtained based on finite element simulation calculation.

[0070] Step 140: During the test duration, acquire multiple average temperature rise values ​​of the second target region and multiple average temperature rise values ​​of the third target region of the heterojunction sample to be tested, so as to obtain the second variation discrete points of the second average temperature rise value changing with time during the test duration, and the third variation discrete points of the third average temperature rise value changing with time during the test duration.

[0071] After obtaining the thermal conductivity and specific heat of the substrate of the heterojunction sample to be tested, a pulsed square wave heating current with an amplitude of I is applied to the heating electrode. b Its pulse width is Δt b , Δt b The duration of the second pulse is d, and its duty cycle is d. b Using thermal imaging methods, such as Figure 3 The average temperature rise ΔT2 of region II at a certain position in the width direction of the heating electrode and the average temperature rise ΔT3 of region III at a certain position in the width direction of the heating electrode are measured to obtain the discrete points of ΔT2 and ΔT3 with time, namely the discrete points of the second and third changes.

[0072] Region II is defined as a distance of l2 to l2 + Δl2 from the heating electrode, and Region III is defined as a distance of l3 to l3 + Δl3 from the heating electrode. The distance parameter l2 can be 1 μm to 5 μm, and Δl2 can be 1 μm to 4 μm. The distance parameter l3 can be 5 μm to 10 μm, and Δl3 can be 1 μm to 4 μm.

[0073] The amplitude I of the pulsed square wave heating current b It can be 50mA to 500mA, with a pulse width Δt. b The duty cycle can be from 200 ns to 50 μs, with a duty cycle d. b It can be 0.5% to 10%.

[0074] In some embodiments of the present invention, in the reflection thermal imaging method, a wavelength of λ is selected. b LED light source, light source wavelength λ b The wavelength range can be 340nm to 780nm, specifically 340nm, 365nm, 405nm, 455nm, 470nm, 505nm, 530nm, 625nm, 656nm, 780nm, etc. The actual selection can be based on the material's temperature coefficient of reflectance (C) at that wavelength. th Choose the corresponding higher C. th The absolute wavelength can be determined by consulting literature or through actual calibration. The reflected thermal light source and the heterojunction sample under test are at a preset distance.

[0075] In some embodiments of the present invention, in the infrared thermal imaging method, the infrared radiation band detected by the infrared array detector can be mid-wave infrared (wavelength range of 3 to 5 μm) or long-wave infrared (wavelength range of 7.5 to 13.5 μm).

[0076] Step 150: Based on finite element simulation calculation, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate.

[0077] After obtaining the second and third variation discrete points within the third test duration, the interfacial thermal resistance and specific heat of the thin film of the heterojunction sample under test are obtained based on finite element simulation calculation.

[0078] Step 160: Based on finite element simulation calculation, according to the discrete points of the third variation within the fourth test duration and the interface thermal resistance, the specific heat of the thin film and the thermal conductivity and specific heat of the substrate, the thermal conductivity of the thin film is obtained;

[0079] The first average temperature rise value, the second average temperature rise value, and the third average temperature rise value are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method.

[0080] During the fourth test duration, the thermal conductivity of the thin film is obtained based on the discrete point of the second variation, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate.

[0081] In some embodiments, within the test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test are acquired to obtain the first discrete points of the first average temperature rise value changing with time within the first test duration, further comprising:

[0082] A heating electrode is disposed on at least a portion of the surface of the thin film of the heterojunction sample to be tested, wherein the heating electrode has a predetermined width;

[0083] A pulsed square wave heating current with preset parameters is applied to the heating electrode;

[0084] The pulse width of the pulse current is Δt. a .

[0085] Specifically, a heating electrode 205 is disposed on at least a portion of the surface of the thin film away from the substrate, the width of which is expressed as W. h Sample structure reference Figure 2 and Figure 3 Then, a pulsed square wave heating current with an amplitude of I is applied to the heating electrode. a Its pulse width is Δt a , Δta The duration of the first pulse is d, and its duty cycle is d. a After obtaining the thermal conductivity and specific heat of the substrate of the heterojunction sample to be tested, a pulsed square wave heating current with an amplitude of I is applied to the heating electrode. b Its pulse width is Δt b , Δt b The duration of the second pulse is d, and its duty cycle is d. b Pulse waveform reference Figure 4 In some embodiments of the present invention, the width W of the heating electrode h It can range from 2μm to 10μm.

[0086] In one embodiment of the present invention, if the material of the thin film has good insulation properties, a wide heating electrode, a narrow heating electrode, and a detection electrode can be directly disposed on the surface of the thin film; if the material forming the thin film has good conductivity, an insulating layer can be disposed on the surface of the thin film to prevent electrode crosstalk and leakage.

[0087] The material of the heating electrode is not particularly limited and can be selected from commonly used electrode materials in the art. For example, the heating electrode in this application is selected independently from at least one of Au, Pt, Pd, Ag, Cr, Ni, Ti, Cu and Al.

[0088] In some embodiments, based on finite element simulation calculations, the thermal conductivity of the substrate of the heterojunction sample under test is obtained according to the first discrete point of change within the first test duration, specifically including:

[0089] After the pulse begins, Δt a ~2Δt a The time range is defined as the first test duration. Within the first test duration, the thermal conductivity k of the substrate is obtained through univariate inversion based on finite element simulation and the first discrete point of change. sub .

[0090] Specifically, within the time range of the first test duration after the pulse begins, based on finite element simulation and through univariate inversion, the thermal conductivity k of the substrate is obtained from the first discrete point of change. sub In other words, the duration of the first test is Δt after the pulse begins. a ~2Δt a Within the time range, at this point, the pulse stops, and the temperature of the heating electrode drops. During the Δt period after the pulse stops... a ~2Δt a Within a time range, the thermal conductivity k of the substrate is obtained from the discrete point of the first change through univariate inversion. sub .

[0091] In some embodiments, based on finite element simulation calculations, the specific heat of the substrate is obtained according to the discrete point of the first change within the second test duration and the thermal conductivity of the substrate, specifically including:

[0092] From 0 to Δt after the pulse begins a The time range is used as the second test duration. Based on finite element simulation, the specific heat of the substrate is obtained through univariate inversion according to the discrete points of the first variation and the thermal conductivity of the substrate.

[0093] Specifically, after obtaining the thermal conductivity of the substrate, within the second test duration after the pulse begins, based on finite element simulation and through univariate inversion, the specific heat of the substrate is obtained according to the first variation discrete point and the thermal conductivity of the substrate. In other words, the second test duration is from 0 to Δt after the pulse begins. a Within the specified time range, at the start of the pulse, the heating electrode begins to operate, and the temperature of the heterojunction sample under test rises. During the initial pulse period (0~Δt),... a Within a given time frame, based on finite element simulation and through univariate inversion, the specific heat capacity of the substrate is obtained from the discrete point of the first variation and the thermal conductivity of the substrate.

[0094] In some embodiments, multiple second-mean average temperature rise values ​​of the second target region and multiple third-mean average temperature rise values ​​of the third target region of the heterojunction sample under test are obtained to obtain the second-mean average temperature rise value as a function of time within the test duration and the third-mean average temperature rise value as a function of time within the test duration. This is further included before:

[0095] A pulsed square wave heating current with preset parameters is applied to the heating electrode;

[0096] The pulse width of the pulse current is Δt. b .

[0097] Specifically, after obtaining the thermal conductivity and specific heat of the substrate of the heterojunction sample to be tested, a pulsed square wave heating current with an amplitude of I is applied to the heating electrode. b Its pulse width is Δt b , Δt b The duration of the second pulse is d, and its duty cycle is d. b Pulse waveform reference Figure 4 In some embodiments of the present invention, the width W of the heating electrode h It can range from 2μm to 10μm.

[0098] In some embodiments, based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Specifically, this includes:

[0099] From 0 to 2Δt after the pulse begins b The time range is defined as the third test duration. Within the third test duration, based on finite element simulation, the specific heat of the thin film is obtained by least squares inversion using the least squares method according to the discrete points of the second variation and the thermal conductivity and specific heat of the substrate. The interfacial thermal resistance R9 between the substrate and the thin film.

[0100] Specifically, within the third test duration after the pulse begins, based on finite element simulation, and according to the discrete point of the second variation and the thermal conductivity and specific heat of the substrate, the specific heat of the thin film is obtained by least squares inversion. and the interfacial thermal resistance R between the substrate and the thin film I In other words, the duration of the third test is 0 to 2Δt after the pulse begins. b The time range is such that the pulse starts at time 0 and lasts for Δt. b Then the pulse stops, lasting Δt. b The heating electrode is in the range of 0 to Δt. b During the time range of operation, the temperature of the heterojunction sample under test rises, lasting Δt. b After that, at Δt b ~2Δt b Within the time range, the pulse stops, and the temperature of the heterojunction sample under test drops (cools down), lasting Δt. b 0–2Δt after the pulse begins b Within a given time frame, based on finite element simulation, and according to the discrete points of the second variation and the thermal conductivity and specific heat of the substrate, the specific heat of the thin film is obtained by least squares inversion. and the interfacial thermal resistance R between the substrate and the thin film I .

[0101] In some embodiments, based on finite element simulation calculations, the thermal conductivity of the thin film is obtained according to the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. Specifically, this includes:

[0102] From 0 to Δt after the pulse begins b The time range is used as the fourth test duration. Based on finite element simulation, the thermal conductivity k of the thin film is obtained by univariate inversion based on the discrete points of the third variation and the interface thermal resistance, the specific heat of the thin film, and the thermal conductivity of the substrate. f .

[0103] Specifically, the specific heat of the thin film is obtained. Interfacial thermal resistance R between substrate and thin film I Subsequently, within the fourth test duration after the pulse begins, based on finite element simulation, and according to the discrete point of the third variation and the interface thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate, the thermal conductivity k of the thin film is obtained through univariate inversion. f In other words, the duration of the fourth test is from 0 to Δt after the pulse begins. b The time range is such that the pulse starts at time 0 and lasts for Δt. b The heating electrode operates, and the heterojunction sample under test is heated. During the pulse's initial phase (0~Δt)... b Within a given time frame, based on finite element simulation, and considering the discrete points of the third variation, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate, the thermal conductivity k of the thin film is obtained through univariate inversion. f .

[0104] Based on the above embodiments, the present invention provides an example of completing a measurement using the above-described method for measuring the thermophysical properties of heterojunctions based on thermal imaging.

[0105] A 2μm gallium nitride heterojunction sample epitaxially grew on a silicon carbide substrate had an insulating layer made of aluminum oxide with a thickness of 50nm placed on the side of the gallium nitride layer away from the silicon carbide. A heating electrode was placed on the surface of the insulating layer away from the gallium nitride film. The specific heat, thermal conductivity, and interfacial thermal resistance of the film and substrate of the heterojunction sample were measured using reflective thermal imaging. The specific process is as follows:

[0106] (1) A heating electrode with a width of 5 μm is disposed on at least a portion of the surface of the thin film away from the substrate.

[0107] (2) A pulsed square wave heating current with an amplitude of 200 mA, a pulse width of 10 μs, and a duty cycle of 5% is applied to the heating electrode. Using reflective thermal imaging, an LED light source with a wavelength of 365 nm is selected to measure the first average temperature rise ΔT1 of region I on the sample surface at a certain position in the width direction of the heating electrode, and the first discrete point of the change of ΔT1 over time is obtained. The range of region I is 5 μm to 10 μm from the heating electrode. Within the time range of 10 μs to 20 μs after the pulse starts, the thermal conductivity k of the substrate is obtained by univariate inversion based on finite element simulation. sub 340 W·m -1 ·K -1 ; obtain k sub Subsequently, within a time range of 0–10 μs after the pulse begins, the specific heat of the substrate is obtained through univariate inversion based on finite element simulation. 675 J·kg -1 K -1 .

[0108] (3) A pulsed square wave heating current with an amplitude of 280 mA, a pulse width of 800 ns, and a duty cycle of 2% is applied to the heating electrode. Using reflective thermal imaging, an LED light source with a wavelength of 365 nm is selected. The average temperature rise ΔT2 in region II at a certain position along the width of the heating electrode and the average temperature rise ΔT3 in region III at a certain position along the width of the heating electrode are measured. The discrete points of the second and third changes of ΔT2 and ΔT3 over time are obtained. The range of region II is 2 μm to 4 μm from the heating electrode, and the range of region III is 8 μm to 10 μm from the heating electrode. Within the time range of 0 to 1.6 μs after the pulse starts, the specific heat of the thin film is obtained by least squares inversion based on finite element simulation. 470 J·kg -1 K -1 The interfacial thermal resistance R between the substrate and the thin film is obtained. I 12m 2 K·GW -1 ;get and R I Then, within a time range of 0–800 ns after the pulse begins, the thermal conductivity k of the thin film is obtained through univariate inversion based on finite element simulation. f 180 W·m -1 K -1 .

[0109] The final test results are shown in Table 1.

[0110] Table 1 Final Test Results

[0111]

[0112] In summary, the experimental results shown in Table 1 demonstrate that the method proposed in this application can accurately measure the specific heat, thermal conductivity, and interfacial thermal resistance of heterostructured thin films and substrates. The measurement results are consistent with the reference values ​​in the literature, proving the practicality and reliability of this method.

[0113] In the above specific embodiments, the method for measuring the thermophysical properties of heterojunctions based on thermal imaging provided by the present invention obtains multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test within a test duration, so as to obtain the first discrete points of the first average temperature rise value changing with time within the test duration; based on finite element simulation calculation, the thermal conductivity of the substrate of the heterojunction sample under test is obtained according to the first discrete points of change within the first test duration; based on finite element simulation calculation, the specific heat of the substrate is obtained according to the first discrete points of change and the thermal conductivity of the substrate within a second test duration; within the test duration, multiple second average temperature rise values ​​of the second target region and multiple third average temperature rise values ​​of the third target region of the heterojunction sample under test are obtained. The discrete points of the second average temperature rise value and the third average temperature rise value over time within the test duration are obtained. Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained according to the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. The first, second, and third average temperature rise values ​​are obtained by measuring the surface of the heterojunction sample under test using thermal imaging methods. This invention utilizes a heating electrode placed on the surface of a thin film away from the substrate, connected to a pulsed square wave heating current, and employs thermal imaging to test the temperature rise changes of different regions on the sample surface at different times. Combined with finite element simulation calculations, the required parameters are obtained, enabling simultaneous measurement of multiple parameters. It only requires pulsed current heating and a limited number of tests, making the testing process efficient and fast. By leveraging the different sensitivities of temperature rise changes in different regions and time periods to different physical properties, thermal properties are gradually inverted, avoiding the use of multi-parameter fitting algorithms and improving the solution accuracy.

[0114] The thermophysical property measurement device based on thermal imaging provided by the present invention will be described below. The thermophysical property measurement device based on thermal imaging described below can be referred to in correspondence with the thermophysical property measurement method based on thermal imaging described above.

[0115] Figure 5 A schematic diagram of the structure of the heterojunction thermophysical property measurement device based on thermal imaging provided by the present invention is shown below. Figure 5 As shown, it includes a first test module 510, a first calculation module 520, a second test module 530, and a second calculation module 540.

[0116] in:

[0117] The first test module 510 is used to acquire multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test within the test duration, so as to obtain the first variation discrete point of the first average temperature rise value as a function of time within the test duration;

[0118] The first calculation module 520 is used to calculate the thermal conductivity of the substrate of the heterojunction sample under test based on the first variation discrete point within the first test duration, and to calculate the specific heat of the substrate based on the first variation discrete point within the second test duration and the thermal conductivity of the substrate, based on the finite element simulation.

[0119] The second test module 530 is used to acquire multiple second average temperature rise values ​​of the second target region and multiple third average temperature rise values ​​of the third target region of the heterojunction sample under test within the test duration, so as to obtain the second variation discrete points of the second average temperature rise value changing with time within the test duration and the third variation discrete points of the third average temperature rise value changing with time within the test duration.

[0120] The second calculation module 540 is used to calculate the interfacial thermal resistance and specific heat of the heterojunction sample under test based on finite element simulation, according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate; and to calculate the thermal conductivity of the thin film based on the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate.

[0121] The first average temperature rise value, the second average temperature rise value, and the third average temperature rise value are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method.

[0122] Based on the above embodiments, in this device, within the test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample to be tested are acquired to obtain the first discrete points of the first average temperature rise value changing with time within the first test duration. Prior to this, the device further includes:

[0123] A heating electrode is disposed on at least a portion of the surface of the thin film of the heterojunction sample to be tested, wherein the heating electrode has a predetermined width;

[0124] A pulsed square wave heating current with preset parameters is applied to the heating electrode;

[0125] The pulse width of the pulse current is Δt. a .

[0126] Based on the above embodiments, in this device, the thermal conductivity of the substrate of the heterojunction sample under test is obtained based on the first discrete point of change within the first test duration, according to finite element simulation calculations. Specifically, this includes:

[0127] After the pulse begins, Δt a ~2Δt a The time range is defined as the first test duration. Within the first test duration, the thermal conductivity k of the substrate is obtained through univariate inversion based on finite element simulation and the first discrete point of change. sub .

[0128] Based on the above embodiments, in this device, the specific heat of the substrate is obtained based on finite element simulation calculations, according to the discrete point of the first change within the second test duration and the thermal conductivity of the substrate, specifically including:

[0129] From 0 to Δt after the pulse begins a The time range is used as the second test duration. Based on finite element simulation, the specific heat of the substrate is obtained through univariate inversion according to the discrete points of the first variation and the thermal conductivity of the substrate.

[0130] Based on the above embodiments, in this device, multiple second-level average temperature rise values ​​of the second target region and multiple third-level average temperature rise values ​​of the third target region of the heterojunction sample to be tested are acquired to obtain the second-level variation discrete points of the second-level average temperature rise value changing with time during the test duration and the third-level variation discrete points of the third-level average temperature rise value changing with time during the test duration. Prior to this, the device further includes:

[0131] A pulsed square wave heating current with preset parameters is applied to the heating electrode;

[0132] The pulse width of the pulse current is Δt. b .

[0133] Based on the above embodiments, in this device, based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate, specifically including:

[0134] From 0 to 2Δt after the pulse begins b The time range is defined as the third test duration. Within the third test duration, based on finite element simulation, the specific heat of the thin film is obtained by least squares inversion using the least squares method according to the discrete points of the second variation and the thermal conductivity and specific heat of the substrate. and the interfacial thermal resistance R between the substrate and the thin film I .

[0135] Based on the above embodiments, in this device, based on finite element simulation calculations, the thermal conductivity of the thin film is obtained according to the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. Specifically, this includes:

[0136] From 0 to Δt after the pulse begins b The time range is used as the fourth test duration. Based on finite element simulation, the thermal conductivity k of the thin film is obtained by univariate inversion based on the discrete points of the third variation and the interface thermal resistance, the specific heat of the thin film, and the thermal conductivity of the substrate. f .

[0137] In the above specific embodiments, the heterojunction thermophysical property measurement device based on thermal imaging provided by the present invention acquires multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test within a test duration, thereby obtaining the first discrete points of the first average temperature rise value changing with time within the test duration; based on finite element simulation calculation, the thermal conductivity of the substrate of the heterojunction sample under test is obtained according to the first discrete points of change within the first test duration; based on finite element simulation calculation, the specific heat of the substrate is obtained according to the first discrete points of change and the thermal conductivity of the substrate within a second test duration; and within the test duration, multiple second average temperature rise values ​​of the second target region and multiple third average temperature rise values ​​of the third target region of the heterojunction sample under test are acquired. The discrete points of the second average temperature rise value and the third average temperature rise value over time within the test duration are obtained. Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained according to the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. The first, second, and third average temperature rise values ​​are obtained by measuring the surface of the heterojunction sample under test using thermal imaging methods. This invention utilizes a heating electrode placed on the surface of a thin film away from the substrate, connected to a pulsed square wave heating current, and employs thermal imaging to test the temperature rise changes of different regions on the sample surface at different times. Combined with finite element simulation calculations, the required parameters are obtained, enabling simultaneous measurement of multiple parameters. It only requires pulsed current heating and a limited number of tests, making the testing process efficient and fast. By leveraging the different sensitivities of temperature rise changes in different regions and time periods to different physical properties, thermal properties are gradually inverted, avoiding the use of multi-parameter fitting algorithms and improving the solution accuracy.

[0138] Figure 6 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 6 As shown, the electronic device may include: a processor 610, a communication interface 620, a memory 630, and a communication bus 640, wherein the processor 610, the communication interface 620, and the memory 630 communicate with each other through the communication bus 640. The processor 610 can call logic instructions in the memory 630 to execute a method for measuring the thermophysical properties of a heterojunction based on thermal imaging. This method includes: acquiring multiple first average temperature rise values ​​of a first target region of the heterojunction sample under test within a test duration, to obtain first discrete points of the first average temperature rise value changing with time within the test duration; calculating the thermal conductivity of the substrate of the heterojunction sample under test based on finite element simulation, according to the first discrete points of the first change within a first test duration; calculating the specific heat of the substrate based on the first discrete points of the first change within a second test duration and the thermal conductivity of the substrate; and acquiring multiple second average temperature rise values ​​of a second target region and multiple third average temperature rise values ​​of a third target region of the heterojunction sample under test within the test duration. The average temperature rise value is used to obtain the second average temperature rise value as a discrete point of change over time within the test duration, and the third average temperature rise value as a discrete point of change over time within the test duration. Based on finite element simulation calculation, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the second average temperature rise value as a discrete point of change over time within the third test duration and the thermal conductivity and specific heat of the substrate. Based on finite element simulation calculation, the thermal conductivity of the thin film is obtained according to the third average temperature rise value as a discrete point of change over time within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. The first, second, and third average temperature rise values ​​are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method.

[0139] Furthermore, the logical instructions in the aforementioned memory 630 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0140] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the method for measuring the thermophysical properties of heterojunctions based on thermal imaging provided by the methods described above. This method includes: acquiring multiple first average temperature rise values ​​of a first target region of a heterojunction sample under test within a test duration, to obtain first discrete points of the first average temperature rise value changing with time within the test duration; obtaining the thermal conductivity of the substrate of the heterojunction sample under test based on finite element simulation calculations and the first discrete points of change within a first test duration; obtaining the specific heat of the substrate based on the first discrete points of change and the thermal conductivity of the substrate within a second test duration based on finite element simulation calculations; and acquiring multiple... The second average temperature rise value and multiple third average temperature rise values ​​of the third target area are used to obtain the second variation discrete points of the second average temperature rise value over time within the test duration, and the third average temperature rise value over time within the test duration. Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the second variation discrete points within the third test duration and the thermal conductivity and specific heat of the substrate. Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained according to the third variation discrete points within the fourth test duration and the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. The first average temperature rise value, the second average temperature rise value, and the third average temperature rise value are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method.

[0141] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0142] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring the thermophysical properties of heterojunctions based on thermal imaging, characterized in that, include: During the test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample to be tested are obtained to obtain the first discrete points of the first average temperature rise value changing with time during the test duration; Based on finite element simulation calculations, the thermal conductivity of the substrate of the heterojunction sample under test is obtained according to the discrete points of the first change within the first test duration. Based on finite element simulation calculations, the specific heat of the substrate is obtained according to the discrete points of the first change within the second test duration and the thermal conductivity of the substrate; Within the test duration, multiple second-average temperature rise values ​​of the second target region and multiple third-average temperature rise values ​​of the third target region of the heterojunction sample under test are obtained to obtain the second variation discrete points of the second-average temperature rise value as a function of time within the test duration, and the third variation discrete points of the third-average temperature rise value as a function of time within the test duration. Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained by considering the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. The first average temperature rise value, the second average temperature rise value, and the third average temperature rise value are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method. Within the test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test are acquired to obtain the first discrete points of the first average temperature rise value changing with time within the first test duration. This process also includes: A heating electrode is disposed on at least a portion of the surface of the thin film of the heterojunction sample to be tested; The first target region is located at a distance of l1 to l1+Δl1 from the heating electrode; l1 is 3μm to 8μm and Δl1 is 2μm to 7μm. The second target region is located at a distance of l2 to l2+Δl2 from the heating electrode; l2 is 1μm to 5μm and Δl2 is 1μm to 4μm. The third target region is located at a distance of l3 to l3+Δl3 from the heating electrode; l3 is 5μm to 10μm and Δl3 is 1μm to 4μm.

2. The method for measuring the thermophysical properties of heterojunctions based on thermal imaging according to claim 1, characterized in that, During the test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test are acquired to obtain the first discrete points of the first average temperature rise value changing with time during the first test duration. Previously, include: The heating electrode has a preset width; A first pulse square wave heating current with preset parameters is applied to the heating electrode; Wherein, the pulse width of the first pulse square wave heating current is .

3. The method for measuring the thermophysical properties of heterojunctions based on thermal imaging according to claim 2, characterized in that, Based on finite element simulation calculations, the thermal conductivity of the substrate of the heterojunction sample under test is obtained according to the discrete points of the first variation within the first test duration, specifically including: After the pulse begins ~ The time range is defined as the first test duration. Within the first test duration, the thermal conductivity of the substrate is obtained through univariate inversion based on finite element simulation and the first discrete point of change. .

4. The method for measuring the thermophysical properties of heterojunctions based on thermal imaging according to claim 2, characterized in that, Based on finite element simulation calculations, the specific heat of the substrate is obtained according to the discrete points of the first change within the second test duration and the thermal conductivity of the substrate, specifically including: After the pulse starts, 0~ The time range is used as the second test duration. Based on finite element simulation, the specific heat of the substrate is obtained through univariate inversion according to the discrete points of the first variation and the thermal conductivity of the substrate. .

5. The method for measuring the thermophysical properties of heterojunctions based on thermal imaging according to claim 1, characterized in that, To obtain multiple second-level average temperature rise values ​​for the second target region and multiple third-level average temperature rise values ​​for the third target region of the heterojunction sample under test, in order to obtain the second-level variation discrete points of the second-level average temperature rise value and the third-level variation discrete points of the third-level average temperature rise value over time during the test duration, the method further includes: A second pulse square wave heating current with preset parameters is applied to the heating electrode; The pulse width of the second pulse square wave heating current is... .

6. The method for measuring the thermophysical properties of heterojunctions based on thermal imaging according to claim 5, characterized in that, Based on finite element simulation calculations, the interfacial thermal resistance and specific heat of the heterojunction sample under test are obtained according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Specifically, this includes: After the pulse starts, 0~ The time range is defined as the third test duration. Within the third test duration, based on finite element simulation, the specific heat of the thin film is obtained by least squares inversion using the least squares method according to the discrete points of the second variation and the thermal conductivity and specific heat of the substrate. and the interfacial thermal resistance between the substrate and the thin film .

7. The method for measuring the thermophysical properties of heterojunctions based on thermal imaging according to claim 5, characterized in that, Based on finite element simulation calculations, and according to the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate, the thermal conductivity of the thin film is obtained, specifically including: After the pulse starts, 0~ The time range is used as the fourth test duration. Based on finite element simulation, the thermal conductivity of the thin film is obtained by univariate inversion based on the discrete points of the third variation and the interface thermal resistance, the specific heat of the thin film, and the thermal conductivity of the substrate. .

8. A device for measuring the thermophysical properties of a heterojunction based on thermal imaging, characterized in that, include: The first test module is used to acquire multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test within the test duration, so as to obtain the first discrete point of the first average temperature rise value changing with time within the test duration; The first calculation module is used to calculate the thermal conductivity of the substrate of the heterojunction sample under test based on the first discrete point of change within the first test duration, using finite element simulation. Based on finite element simulation calculations, the specific heat of the substrate is obtained according to the discrete points of the first change within the second test duration and the thermal conductivity of the substrate; The second testing module is used to acquire multiple second average temperature rise values ​​of the second target region and multiple third average temperature rise values ​​of the third target region of the heterojunction sample under test within the test duration, so as to obtain the second variation discrete points of the second average temperature rise value changing with time within the test duration and the third variation discrete points of the third average temperature rise value changing with time within the test duration. The second calculation module is used to calculate the interfacial thermal resistance and specific heat of the heterojunction sample under test based on finite element simulation calculations, according to the discrete points of the second variation within the third test duration and the thermal conductivity and specific heat of the substrate. Based on finite element simulation calculations, the thermal conductivity of the thin film is obtained by considering the discrete points of the third variation within the fourth test duration, the interfacial thermal resistance, the specific heat of the thin film, and the thermal conductivity and specific heat of the substrate. The first average temperature rise value, the second average temperature rise value, and the third average temperature rise value are obtained by measuring the surface of the heterojunction sample under test using a thermal imaging method. In the device, during the test duration, multiple first average temperature rise values ​​of the first target region of the heterojunction sample under test are acquired to obtain the first discrete points of the first average temperature rise value changing with time during the first test duration. Prior to this, the device further includes: A heating electrode is disposed on at least a portion of the surface of the thin film of the heterojunction sample to be tested; The first target region is located at a distance of l1 to l1+Δl1 from the heating electrode; l1 is 3μm to 8μm and Δl1 is 2μm to 7μm. The second target region is located at a distance of l2 to l2+Δl2 from the heating electrode; l2 is 1μm to 5μm and Δl2 is 1μm to 4μm. The third target region is located at a distance of l3 to l3+Δl3 from the heating electrode; l3 is 5μm to 10μm and Δl3 is 1μm to 4μm.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method for measuring the thermophysical properties of heterojunctions based on thermal imaging as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for measuring the thermophysical properties of heterojunctions based on thermal imaging as described in any one of claims 1 to 7.

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