Thermochromic structures and methods of making the same, microelectronic devices

Abstract

The application relates to a thermochromic structure, a preparation method thereof and a microelectronic device. The thermochromic structure comprises a reflective layer, a spacer layer and a thermochromic layer which are sequentially stacked, the reflective layer comprises an indium tin oxide layer, the spacer layer comprises a zinc oxide layer, and the thermochromic layer comprises a vanadium oxide layer. When the temperature rises, the thermochromic structure can improve the thermal emissivity of the thermochromic structure in response to temperature change, conduct heat to the outside world, realize effective heat dissipation, and be suitable for heat dissipation of microelectronic devices with small sizes.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to thermochromic structures and their preparation methods, and microelectronic devices. Background Technology

[0002] With the continuous iteration of semiconductor manufacturing processes and the rapid evolution of electronic devices towards miniaturization, high power, and integration, the power density of microelectronic devices continues to break through the upper limit. Accompanying this is a sharp increase in heat flux density, and high temperature has become one of the core bottlenecks restricting the development of microelectronic devices. High-temperature environments degrade the electrical performance parameters of devices, leading to signal transmission delays and increased power consumption. At the same time, they accelerate the aging and wear of internal materials, significantly reducing their operational reliability, shortening their service life, and in severe cases, even causing thermal failure of the devices.

[0003] Currently, heat dissipation for electronic devices mainly includes natural heat dissipation, forced heat dissipation, liquid heat dissipation, refrigeration, heat conduction, and thermal isolation. Natural heat dissipation relies on natural convection and thermal radiation, requiring no additional power source. It is simple in structure, low in cost, and suitable for low-power, low-heat-flux-density scenarios, achieving temperature control through natural heat exchange between the heat-generating device and its surrounding environment. Forced heat dissipation uses fans, blowers, and other powered components to accelerate airflow around the device, enhancing convective heat transfer efficiency. Liquid heat dissipation utilizes the high specific heat capacity and thermal conductivity of liquid working fluids to remove heat from the device through indirect heat exchange or direct contact. Refrigeration primarily achieves active cooling through refrigerant phase change heat absorption or the semiconductor cooling effect, achieving cooling below ambient temperature. Heat conduction uses heat pipes to transfer heat dissipated by electronic devices to another environment. Thermal isolation heat dissipation utilizes insulating materials or structural design to treat heat dissipation and cooling of electronic devices.

[0004] Although there are various methods for heat dissipation of electronic devices, traditional heat dissipation technologies have significant limitations due to the small size of microelectronic devices: the power components such as fans required for forced cooling are too large to be integrated with microelectronic devices; the structural design and manufacturing process of heat pipes are difficult to adapt to the micron-scale, and their heat conduction advantages cannot be effectively utilized; the piping and sealing structure of liquid cooling is difficult to miniaturize, which greatly increases the risk of leakage; and the high energy consumption and complex structure of refrigeration cannot meet the miniaturization and low power consumption requirements of microelectronic devices.

[0005] Therefore, it is necessary to improve traditional technologies. Summary of the Invention

[0006] Based on this, this application provides a thermochromic structure adapted to the microscale, which has both temperature response and efficient heat dissipation, as well as its preparation method and microelectronic device.

[0007] The technical solution to the above-mentioned technical problems in this application is as follows.

[0008] The first aspect of this application provides a thermochromic structure, comprising a reflective layer, a spacer layer and a thermochromic layer stacked sequentially, wherein the reflective layer comprises an indium tin oxide layer, the spacer layer comprises a zinc oxide layer and the thermochromic layer comprises a vanadium oxide layer.

[0009] In some embodiments, the thermochromic structure satisfies at least one of the following characteristics:

[0010] (1) The thickness of the spacer layer is 50 nm to 140 nm;

[0011] (2) The thickness of the thermochromic layer is 30 nm to 100 nm.

[0012] In some embodiments, the thickness ratio of the spacer layer to the thermochromic layer in the thermochromic structure is 1 to 4:1.

[0013] In some embodiments, the thickness of the reflective layer in the thermochromic structure is 100 nm to 200 nm.

[0014] In some embodiments, in the thermochromic structure, the reflective layer is an indium tin oxide layer, the spacer layer is a zinc oxide layer, and the thermochromic layer is a vanadium oxide layer.

[0015] A second aspect of this application provides a method for preparing a thermochromic structure, comprising the following steps:

[0016] A reflective layer, a spacer layer, and a thermochromic layer are sequentially deposited on a substrate. The reflective layer includes an indium tin oxide layer, the spacer layer includes a zinc oxide layer, and the thermochromic layer includes a vanadium oxide layer.

[0017] In some embodiments, the methods for depositing the indium tin oxide layer, the zinc oxide layer, and the vanadium oxide layer in the preparation method of the thermochromic structure are independently selected from magnetron sputtering or sol-gel methods.

[0018] In some embodiments, the parameters of the magnetron sputtering method used in the fabrication of the thermochromic structure include: cavity vacuum degree ≤ 5.0 × 10⁻⁶. -4 Pa, the working gas is argon, the working pressure is 0.5 Pa~0.6 Pa, and the sputtering power is 20 W~60 W.

[0019] A third aspect of this application provides a microelectronic device, including a device body and a thermochromic structure prepared by the method of preparing the thermochromic structure provided in the first aspect or the method of preparing the thermochromic structure provided in the second aspect, wherein the thermochromic structure is disposed on the surface of the device body and the reflective layer is disposed between the device body and the spacer layer.

[0020] In some embodiments, the device body in a microelectronic device includes a CPU or a Micro-LED.

[0021] The thermochromic structure of this application includes a reflective layer, a spacer layer, and a thermochromic layer stacked sequentially. An indium tin oxide layer is used as the reflective layer, providing high reflectivity in the near-infrared and mid-infrared bands. A vanadium oxide layer is used as the thermochromic layer, and a zinc oxide layer is used as the spacer layer. Utilizing the structural induction effect of zinc oxide on vanadium oxide, when the temperature exceeds the phase transition point, vanadium oxide transforms from a low-temperature monoclinic phase to a high-temperature rutile phase, increasing its emissivity in the infrared band. This allows the thermochromic structure to respond to temperature changes and increase its thermal emissivity as the temperature rises, conducting heat to the outside for effective heat dissipation and improving the stability of the optical resonance environment.

[0022] The thermochromic structure of this application is suitable for heat dissipation of small-sized microelectronic devices. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of a thermochromic structure provided in one embodiment;

[0025] Figure 2 A schematic diagram of the structure of a microelectronic device provided in one embodiment;

[0026] Figure 3 Comparison of infrared emissivity spectra of the thermochromic structures prepared in Examples 1, 2 and 3 at low temperature (27°C) and high temperature (80°C).

[0027] Figure label:

[0028] 10: Thermochromic structure; 11: Reflective layer; 12: Spacer layer; 13: Thermochromic layer; 20: Device body. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive.

[0030] It should also be understood that this application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various alterations or modifications without departing from the spirit of this application, and the resulting equivalent forms also fall within the protection scope of this application. For example, features described or illustrated as part of one embodiment can be combined in a suitable manner in another embodiment to produce new embodiments. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of this application; it should be understood that this application can be implemented without one or more of these details.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for descriptive purposes only and is not intended to be limiting of the application.

[0032] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0033] In this application, the terms "multiple", "various", "multiple times", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0034] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0035] In this document, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0036] In this document, terms such as "preferred," "better," "more suitable," and "ideal" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0037] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0038] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0039] In this application, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0040] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0041] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0042] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0043] In this application, the terms "room temperature" or "normal temperature" generally refer to 4℃ to 35℃, for example, 20℃ ± 5℃. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10℃ to 30℃. In some embodiments of this application, "room temperature" or "normal temperature" refers to 20℃ to 30℃.

[0044] In this application, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0045] The mass or weight of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship of mass or weight between the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass or weight mentioned in the embodiments of this application can be units known in the chemical industry, such as μg, mg, g, and kg.

[0046] See Figure 1 One embodiment of this application provides a thermochromic structure 10, including a reflective layer 11, a spacer layer 12 and a thermochromic layer 13 stacked sequentially. The reflective layer 11 includes an indium tin oxide layer, the spacer layer 12 includes a zinc oxide layer, and the thermochromic layer 13 includes a vanadium oxide layer.

[0047] The aforementioned thermochromic structure utilizes the reflection and transmission properties of different layers to regulate light transmission and reflection through interference effects and phase transitions in the thermochromic material, thereby achieving directional control of thermal radiation. Specifically, an indium tin oxide (ITO) layer serves as the reflective layer, providing high reflectivity in the near-infrared and mid-infrared bands; a zinc oxide (ZnO) layer acts as the spacer layer, controlling the structure's radiation characteristics through optical interference effects; and a vanadium oxide (VO2) layer serves as the thermochromic layer, with a phase transition temperature of approximately 68°C. When the temperature exceeds the phase transition point, VO2 transitions from a low-temperature monoclinic phase (semiconductor phase) to a high-temperature rutile phase (metallic phase), effectively enhancing its emissivity in the infrared band. When the thermochromic structure is at low temperatures, its overall emissivity is low, which is beneficial for heat preservation and preventing overcooling of the device. When the operating temperature of the microelectronic device rises and triggers the VO2 phase transition, the thermal emissivity of the thermochromic structure increases, effectively dissipating the heat generated by the device to the external environment through radiation, achieving passive radiative heat dissipation.

[0048] The aforementioned thermochromic structure is suitable for heat dissipation of small-sized microelectronic devices.

[0049] In some of these examples, the thermochromic structure has an indium tin oxide layer as the reflective layer, a zinc oxide layer as the spacer layer, and a vanadium oxide layer as the thermochromic layer.

[0050] In some examples, the thickness of the spacer layer in the thermochromic structure is 50 nm to 140 nm. It is understood that the thickness of the spacer layer in the thermochromic structure includes, but is not limited to, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, and 140 nm; in some examples, it can be within a range formed by any two of these point values ​​as endpoints. Optionally, the thickness of the spacer layer in the thermochromic structure is 90 nm to 140 nm. Further, the thickness of the spacer layer in the thermochromic structure is 120 nm to 140 nm.

[0051] Studies have found that ZnO has a higher refractive index (n≈2.0) compared to SiO2 (n≈1.45). Using a zinc oxide layer as a spacer allows for better optical path at a thinner physical thickness, which is beneficial for thin-film integration on the surface of microelectronic devices and reduces the additional thermal resistance introduced by excessively thick coatings. Furthermore, the structural induction effect of ZnO on VO2 can improve the stability of the optical resonance environment.

[0052] In some examples, the thickness of the thermochromic layer in the thermochromic structure is 30 nm to 100 nm. It is understood that the thickness of the thermochromic layer in the thermochromic structure includes, but is not limited to, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, and 100 nm; in some examples, it can be within a range formed by any two of these point values ​​as endpoints. Optionally, the thickness of the thermochromic layer in the thermochromic structure is 40 nm to 60 nm. Further, the thickness of the thermochromic layer in the thermochromic structure is 45 nm to 50 nm.

[0053] By controlling the thickness of the thermochromic layer, a good emissivity adjustment capability is ensured while maintaining good light transmittance.

[0054] In some examples, the thickness ratio of the spacer layer to the thermochromic layer in the thermochromic structure is 1 to 4:1. It can be understood that the thickness ratio of the spacer layer to the thermochromic layer in the thermochromic structure includes, but is not limited to, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, and 4:1; in some examples, it can be any two of these point values ​​forming a range. Optionally, in the thermochromic structure, the thickness ratio of the spacer layer to the thermochromic layer is 2~3.5:1. Further, in the thermochromic structure, the thickness ratio of the spacer layer to the thermochromic layer is 3~3.2:1.

[0055] By controlling the thickness ratio of the spacer layer to the thermochromic layer, the precision of controlling the location of interference maxima and the bandwidth of the spectral response can be improved.

[0056] In some examples, the thickness of the reflective layer in the thermochromic structure is 100 nm to 200 nm. It can be understood that the thickness of the reflective layer in the thermochromic structure includes, but is not limited to, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, 155 nm, 160 nm, 165 nm, 170 nm, 175 nm, 180 nm, 185 nm, 190 nm, 195 nm, and 200 nm; in some examples, it can be within a range formed by any two of these point values ​​as endpoints. Optionally, the thickness of the reflective layer in the thermochromic structure is 100 nm to 150 nm. Further, in the thermochromic structure, the thickness of the reflective layer is 100 nm to 120 nm.

[0057] By controlling the thickness of the reflective layer, sufficient carrier concentration and thickness are ensured to achieve optical opacity in the infrared band. This improves lateral conductivity, aids in electrostatic shielding, and ensures that the film stress is not affected, thus guaranteeing the stability of the thermochromic structure in microelectronic devices.

[0058] The thermochromic structure provided in this application can passively respond to and regulate radiation at high temperatures without the need for external energy input, thereby cooling microelectronic devices.

[0059] The thermochromic structure provided in this application can be used in conjunction with existing thermal interface materials, heat sinks and other traditional heat dissipation solutions to form a composite heat dissipation path of "conduction + radiation" and further improve the overall heat dissipation performance.

[0060] One embodiment of this application provides a method for preparing a thermochromic structure, including the following steps:

[0061] A reflective layer, a spacer layer, and a thermochromic layer are sequentially deposited on a substrate. The reflective layer includes an indium tin oxide layer, the spacer layer includes a zinc oxide layer, and the thermochromic layer includes a vanadium oxide layer.

[0062] ZnO exhibits c-axis preferred orientation growth characteristics, resulting in high-quality crystal templates formed on substrates, even on amorphous surfaces of glass or microelectronic devices. The epitaxial growth quality of VO2 largely depends on the lattice matching of the deposition plane. Depositing VO2 films on zinc oxide layers results in a superior (011) crystal plane orientation, enhancing the steepness of the metal-insulator transition and improving infrared modulation contrast.

[0063] In some of these examples, the methods for preparing the thermochromic structure, including depositing the indium tin oxide layer, the zinc oxide layer, and the vanadium oxide layer, are independently selected from either magnetron sputtering or sol-gel methods.

[0064] In some of these examples, the parameters for magnetron sputtering in the fabrication methods of thermochromic structures include: cavity vacuum degree ≤ 5.0 × 10⁻⁶. -4Pa, the working gas is argon, the working pressure is 0.5 Pa~0.6 Pa, and the sputtering power is 20 W~60 W. It is understood that in magnetron sputtering, the working gas pressure includes, but is not limited to, 0.5 Pa, 0.51 Pa, 0.52 Pa, 0.53 Pa, 0.54 Pa, 0.55 Pa, 0.56 Pa, 0.57 Pa, 0.58 Pa, 0.59 Pa, and 0.6 Pa; the sputtering power includes, but is not limited to, 20 W, 21 W, 22 W, 23 W, 24 W, 25 W, 26 W, 27 W, 28 W, 29 W, 30 W, 31 W, 32 W, 33 W, 34 W, 35 W, 36 W, 37 W, 38 W, 39 W, 40 W, 41 W, 42 W, 43 W, 44 W, 45 W, 46 W, 47 W, 48 W, 49 W, 50 W, 51 W, 52 W, 53 W, 54 W, 55 W, 56 W, 57 W, 58 W, 59 W, and 60 W. W; in some examples, it can be any two of these point values ​​forming a range. Optionally, in magnetron sputtering, the working gas pressure is 0.5 Pa to 0.55 Pa. Further, in magnetron sputtering, the working gas pressure is 0.5 Pa to 0.52 Pa. Optionally, in magnetron sputtering, the sputtering power is 30 W to 40 W. Further, in magnetron sputtering, the sputtering power is 35 W to 40 W. By controlling the sputtering power, the uniformity of the film thickness is ensured, while the deposition rate is maintained, and the time cost is controlled.

[0065] In some of these examples, the cavity vacuum level is 1.0 × 10⁻⁶ in magnetron sputtering. -5 Pa ~ 5.0 × 10 -4 Pa. It is understood that the cavity vacuum level includes, but is not limited to, 1.0 × 10⁻⁶ Pa. -5 Pa, 5.0 × 10 -5 Pa, 1.0 × 10 -4 Pa, 5.0 × 10 -4 Pa.

[0066] It is understandable that the substrate can be glass, the surface of a microelectronic device, etc., to form a thermochromic structure on the substrate surface.

[0067] In some of these examples, the substrate is cleaned and surface-treated before the reflective layer is deposited in the fabrication method of the thermochromic structure.

[0068] In some of these examples, the cleaning agents include at least one of acetone, ethanol, and water.

[0069] In some examples, ultrasonic cleaning is performed sequentially using acetone, ethanol, and water. Further, the surface is dried after cleaning. Optionally, the surface is dried using nitrogen gas.

[0070] In some of these examples, a plasma cleaner is used to surface-treat the substrate to remove contaminants from the substrate surface.

[0071] See Figure 2 One embodiment of this application provides a microelectronic device, including a device body 20 and a thermochromic structure 10. The thermochromic structure 10 is disposed on the surface of the device body 20, and a reflective layer 11 is disposed between the device body 20 and the spacer layer 12.

[0072] It can be understood that the thermochromic structure 10 is the thermochromic structure described above or the thermochromic structure prepared by the above method.

[0073] Applying the aforementioned thermochromic structure or the thermochromic structure prepared by the aforementioned method to the surface of a device body enables thermal management of microelectronic devices. When the device temperature rises during operation, the thermochromic structure on the surface responds to the temperature change by increasing its thermal emissivity, effectively dissipating heat from the device through the internal-surface-thermal-thermal-color-structure surface. At low temperatures, the thermochromic structure exhibits a low thermal emissivity, reducing heat loss and preventing overcooling, thus ensuring normal device startup in low-temperature environments.

[0074] In some of these examples, the main components of the microelectronic device include a CPU (Central Processing Unit), a Micro-LED (Micro Light-Emitting Diode), or a PA (Power Amplifier).

[0075] One embodiment of this application provides a method for fabricating a microelectronic device, comprising the following steps:

[0076] A reflective layer, a spacer layer, and a thermochromic layer are sequentially deposited on the device body. The reflective layer includes an indium tin oxide layer, the spacer layer includes a zinc oxide layer, and the thermochromic layer includes a vanadium oxide layer.

[0077] Another embodiment of this application provides a thermal management method for microelectronic devices, including:

[0078] A reflective layer, a spacer layer, and a thermochromic layer are sequentially deposited on the device body. The reflective layer includes an indium tin oxide layer, the spacer layer includes a zinc oxide layer, and the thermochromic layer includes a vanadium oxide layer.

[0079] During device operation, when the temperature rises above the phase transition temperature, the thermal emissivity of the thermochromic structure adaptively increases to enhance infrared radiation heat dissipation and suppress the continuous rise in device temperature.

[0080] This application provides a new solution for heat dissipation in microelectronic devices. The process is simple, low-cost, and easy to scale up, making it suitable for thermal management of devices such as Micro-LEDs and CPUs.

[0081] The present application will be described in further detail below with reference to specific embodiments, but the embodiments of the present application are not limited thereto.

[0082] Example 1

[0083] S1: Take a glass substrate and ultrasonically clean it for 10 minutes in sequence with acetone, anhydrous ethanol and deionized water. Dry the surface with high-purity nitrogen and then remove contaminants from the substrate surface with a plasma cleaner.

[0084] S2: Place the sample stage containing the cleaned substrate into the cavity of the magnetron sputtering instrument and evacuate to 5.0 × 10⁻⁶. -4 Below Pa, high-purity argon gas was introduced as the working gas, and the flow rate was adjusted to stabilize the working gas pressure at 0.5 Pa. The sputtering power was adjusted to 35 W, and pre-sputtering was performed for 5 minutes to clean the ITO target surface. The baffle was then opened, and an ITO thin film with a thickness of 100 nm was sputtered and deposited.

[0085] S3: Replace with ZnO target material and deposit ZnO thin film with a thickness of 140 nm under the same process conditions;

[0086] S4: Replace with VO2 target material and deposit VO2 thin film with a thickness of 45 nm under the same process conditions;

[0087] The resulting structure is Glass / ITO (100 nm) / ZnO (140 nm) / VO2 (45 nm).

[0088] See Figure 2 ,Will Figure 1 The thermochromic structure in this paper is applied to the surface of Micro-LED devices:

[0089] Example 2

[0090] S1: Using the Micro-LED surface as a substrate, ultrasonically clean it for 10 minutes in sequence with acetone, anhydrous ethanol and deionized water, dry the surface with high-purity nitrogen, and then remove contaminants from the substrate surface using a plasma cleaner.

[0091] S2: Place the sample stage containing the cleaned substrate into the cavity of the magnetron sputtering instrument and evacuate to 5.0 × 10⁻⁶.-4 Below Pa, high-purity argon gas was introduced as the working gas, and the flow rate was adjusted to stabilize the working gas pressure at 0.5 Pa. The sputtering power was adjusted to 35 W, and pre-sputtering was performed for 5 minutes to clean the ITO target surface. The baffle was then opened, and an ITO thin film with a thickness of 100 nm was sputtered and deposited.

[0092] S3: Replace with ZnO target material and deposit ZnO thin film with a thickness of 90 nm under the same process conditions;

[0093] S4: Replace with VO2 target material and deposit VO2 thin film with a thickness of 45 nm under the same process conditions;

[0094] The resulting structure is Glass / ITO (100 nm) / ZnO (90 nm) / VO2 (45 nm).

[0095] Example 3

[0096] S1: Using the Micro-LED surface as a substrate, ultrasonically clean it for 10 minutes in sequence with acetone, anhydrous ethanol and deionized water, dry the surface with high-purity nitrogen, and then remove contaminants from the substrate surface using a plasma cleaner.

[0097] S2: Place the sample stage containing the cleaned substrate into the cavity of the magnetron sputtering instrument and evacuate to 5.0 × 10⁻⁶. -4 Below Pa, high-purity argon gas was introduced as the working gas, and the flow rate was adjusted to stabilize the working gas pressure at 0.5 Pa. The sputtering power was adjusted to 35 W, and pre-sputtering was performed for 5 minutes to clean the ITO target surface. The baffle was then opened, and an ITO thin film with a thickness of 100 nm was sputtered and deposited.

[0098] S3: Replace with ZnO target material and deposit ZnO thin film with a thickness of 50 nm under the same process conditions;

[0099] S4: Replace with VO2 target material and deposit VO2 thin film with a thickness of 45 nm under the same process conditions;

[0100] The resulting structure is Glass / ITO (100 nm) / ZnO (50 nm) / VO2 (45 nm).

[0101] Emissivity test: The spectral reflectance and transmittance of the sample in the 2μm~15μm band were measured using an FTIR spectrometer (equipped with an integrating sphere or heating platform), and the total positive emissivity at each temperature was calculated.

[0102] Figure 3 The infrared emissivity spectra of the thermochromic structures prepared in Examples 1, 2, and 3 at low temperature (27°C) and high temperature (80°C) are compared. Figure 3 In this context, "140nm-Low T" refers to the infrared emissivity spectrum of the thermochromic structure prepared in Example 1 at low temperature (27°C), "140nm-High T" refers to the infrared emissivity spectrum of the thermochromic structure prepared in Example 1 at high temperature (80°C), "90nm-Low T" refers to the infrared emissivity spectrum of the thermochromic structure prepared in Example 2 at low temperature (27°C), "90nm-High T" refers to the infrared emissivity spectrum of the thermochromic structure prepared in Example 2 at high temperature (80°C), "50nm-Low T" refers to the infrared emissivity spectrum of the thermochromic structure prepared in Example 3 at low temperature (27°C), and "50nm-High T" refers to the infrared emissivity spectrum of the thermochromic structure prepared in Example 3 at high temperature (80°C).

[0103] from Figure 3 It can be seen that the emissivity of Example 1 is 0.3 at 27℃, and the emissivity increases to 0.53 after the VO2 in the thermochromic structure undergoes a phase transition at 80℃, significantly enhancing the radiative heat dissipation capacity. The emissivity of Example 2 is 0.26 at 27℃, and the emissivity increases to 0.4 after the VO2 in the thermochromic structure undergoes a phase transition at 80℃. The emissivity of Example 3 is 0.26 at 27℃, and the emissivity increases to 0.38 after the VO2 in the thermochromic structure undergoes a phase transition at 80℃. However, the initial emissivity of the sapphire surface used in Micro-LEDs without a deposited thermochromic structure is <0.2, meaning that under high-temperature and high-power operating conditions, it is difficult to dissipate heat through radiation, and the heat load is concentrated on limited conduction and convection paths.

[0104] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0105] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A thermochromic structure, characterized in that, It includes a reflective layer, a spacer layer and a thermochromic layer stacked in sequence. The reflective layer includes an indium tin oxide layer, the spacer layer includes a zinc oxide layer and the thermochromic layer includes a vanadium oxide layer.

2. The thermochromic structure as described in claim 1, characterized in that, The thermochromic structure satisfies at least one of the following characteristics: (1) The thickness of the spacer layer is 50 nm to 140 nm; (2) The thickness of the thermochromic layer is 30 nm to 100 nm.

3. The thermochromic structure as described in claim 2, characterized in that, The thickness ratio of the spacer layer to the thermochromic layer is 1 to 4:

1.

4. The thermochromic structure according to any one of claims 1 to 3, characterized in that, The thickness of the reflective layer is 100 nm to 200 nm.

5. The thermochromic structure according to any one of claims 1 to 3, characterized in that, The reflective layer is an indium tin oxide layer, the spacer layer is a zinc oxide layer, and the thermochromic layer is a vanadium oxide layer.

6. A method for preparing a thermochromic structure, characterized in that, Includes the following steps: A reflective layer, a spacer layer, and a thermochromic layer are sequentially deposited on a substrate. The reflective layer includes an indium tin oxide layer, the spacer layer includes a zinc oxide layer, and the thermochromic layer includes a vanadium oxide layer.

7. The method for preparing the thermochromic structure as described in claim 6, characterized in that, The deposition of the indium tin oxide layer, the zinc oxide layer, and the vanadium oxide layer are each independently selected from magnetron sputtering or sol-gel methods.

8. The method for preparing the thermochromic structure as described in claim 7, characterized in that, The parameters for the magnetron sputtering method include: cavity vacuum degree ≤ 5.0 × 10⁻⁶. -4 Pa, the working gas is argon, the working pressure is 0.5 Pa~0.6 Pa, and the sputtering power is 20 W~60 W.

9. A microelectronic device, characterized in that, The device includes a device body and a thermochromic structure prepared by the method described in any one of claims 1 to 5 or the method described in any one of claims 6 to 8, wherein the thermochromic structure is disposed on the surface of the device body and the reflective layer is disposed between the device body and the spacer layer.

10. The microelectronic device as claimed in claim 9, characterized in that, The main body of the device includes a CPU, Micro-LED, or PA.

Images