Composite functional film, preparation method, semiconductor device and electronic packaging structure

Abstract

The application provides a composite functional film, belonging to the technical field of films, comprising at least two functional layers, and a composite heat dissipation functional layer is located above the interface passivation layer, the composite heat dissipation functional layer takes dielectric material as a matrix, and high-thermal-conductivity insulating nano filler is uniformly dispersed in the matrix to form a heat conduction path penetrating through the composite heat dissipation functional layer, the application changes the passivation layer from a 'thermal insulator' to a 'thermal path', and efficiently conducts heat from a heat source, so that the working temperature of a channel is fundamentally reduced; through an integrated structure, 'low interface state' and 'high heat dissipation capacity' are simultaneously realized, so that the device not only has excellent performance under static or small signal conditions, but also can maintain high output power, high efficiency and low dynamic resistance under actual high-power radio frequency working conditions, and the performance decline caused by self-heating is eliminated; and the device can work safely and stably under a higher power density, so that the performance advantages of GaN material are completely released.

Description

Technical Field

[0001] This application relates to the field of thin film materials technology, and in particular to a composite functional thin film, its preparation method, semiconductor device, and electronic packaging structure. Background Technology

[0002] Gallium nitride (GaN) high electron mobility transistors (HEMTs), with their wide bandgap, high critical breakdown electric field, and extremely high electron saturation velocity, have become the core of a new generation of high-frequency, high-power radio frequency devices. They have shown great application potential in systems such as 5G communication base stations, radar, and satellite communications, and can provide output power and efficiency far superior to traditional silicon-based and gallium arsenide devices.

[0003] In GaN RF power devices, there is an irreconcilable contradiction between the low thermal conductivity of traditional passivation layers (such as SiN) and the enormous heat dissipation requirements generated during high-power RF operation. This contradiction leads to a sharp increase in the device channel temperature, severely limiting its output power, efficiency, and long-term reliability. Specifically, the following points are addressed: 1. Traditional SiN passivation layers have poor thermal conductivity (~1-3 W / mK), forming a "thermal barrier" above the device channel. Heat generated during RF operation is trapped in the channel region, causing the channel temperature to be much higher than ambient temperature. This results in a sharp drop in carrier mobility at high temperatures, leading to decreased RF output power and reduced power-added efficiency (PAE). 2. High temperature is the "number one killer" of semiconductor devices. Sustained excessively high channel temperatures accelerate all degradation mechanisms, resulting in accelerated current collapse, threshold voltage drift, metal-semiconductor contact degradation, and a significantly shortened mean time to failure (MTTF). 3. To prevent overheating and burnout, system design necessitates derating, operating devices at power levels far below their theoretical capabilities. This limits the full realization of GaN's high power density advantage. For heat dissipation, more complex and expensive back-end packaging and cooling technologies (such as TSV and liquid cooling) must be employed, increasing cost and process complexity. Summary of the Invention

[0004] In view of this, it is necessary to provide a composite functional thin film, preparation method, semiconductor device and electronic packaging structure to address the shortcomings of the existing technology, so as to provide a multilayer composite thin film structure with both excellent electrical passivation function and high thermal conductivity. Through material and process innovation, the thermal management function is embedded into the passivation layer, thereby solving the self-heating problem of GaN RF devices from the source.

[0005] To solve the above problems, this application adopts the following technical solution: One objective of this application is to provide a composite functional thin film for semiconductor devices, the thin film comprising at least two functional layers, wherein the layer directly in contact with the surface of the active region of the semiconductor is an interface passivation layer; and a composite heat dissipation functional layer is located above the interface passivation layer, which is based on a dielectric material and uniformly dispersed with highly thermally conductive insulating nanofillers in the matrix to form a thermally conductive path through the composite heat dissipation functional layer.

[0006] In some embodiments, the thin film comprises, from bottom to top, the interface passivation layer, the composite heat dissipation functional layer, and the uppermost dense protective layer, wherein the material of the dense protective layer is a nitrogen-rich nitride or oxide.

[0007] In some embodiments, an ultrathin oxide layer with a thickness of less than 5 nm is further included between the interface passivation layer and the composite heat dissipation functional layer, formed by atomic layer deposition technology.

[0008] In some embodiments, the highly thermally conductive insulating nanofiller is selected from one or more of the following: aluminum nitride nanowires, boron nitride nanosheets, graphene nanosheets, diamond nanoparticles, and alumina nanoparticles, or a mixture thereof.

[0009] In some embodiments, the volume doping ratio of the highly thermally conductive insulating nanofiller in the composite heat dissipation functional layer is 15% to 35%.

[0010] In some embodiments, the volumetric doping ratio is 22% to 28%.

[0011] In some embodiments, the highly thermally conductive insulating nanofiller has a preferred orientation perpendicular to the surface of the semiconductor active region in the composite heat dissipation functional layer.

[0012] In some embodiments, the material of the interface passivation layer is silicon-rich silicon nitride or silicon oxynitride, with a refractive index of 2.10 to 2.50; the matrix of the composite heat dissipation functional layer is silicon nitride; and the material of the dense protective layer is nitrogen-rich silicon nitride.

[0013] In some embodiments, the thickness of the interface passivation layer is 5-15 nm, the thickness of the composite heat dissipation functional layer is 50-200 nm, and the thickness of the dense protective layer is 20-60 nm.

[0014] The second objective of this application is to provide a method for the aforementioned composite functional thin film, comprising the following steps: forming a silicon-rich interface passivation layer on the surface of a semiconductor active region by a low-damage plasma-enhanced chemical vapor deposition process; and simultaneously depositing a dielectric matrix on the interface passivation layer by a hybrid deposition process and introducing and oriented highly thermally conductive insulating nanofillers in situ to form the composite heat dissipation functional layer.

[0015] In some embodiments, the hybrid deposition process is a combination of plasma-enhanced chemical vapor deposition and aerosol-assisted directional assembly; the external directional field is an electric field, a gas flow field, or a combination thereof.

[0016] In some embodiments, the hybrid deposition process combines sputtering deposition with ion implantation embedding.

[0017] In some embodiments, a dense protective layer is deposited on the composite heat dissipation functional layer, the material of which is a nitrogen-rich nitride or oxide.

[0018] The third objective of this application is to provide a semiconductor device, wherein at least one active region of the device is provided with the aforementioned composite functional thin film.

[0019] In some embodiments, the semiconductor device is a radio frequency device or a power electronic device, and the active region material is selected from gallium nitride, gallium arsenide, silicon carbide, and gallium oxide.

[0020] In some embodiments, the semiconductor device is a light-emitting diode or a laser diode.

[0021] The fourth objective of this application is to provide an electronic packaging structure comprising the aforementioned composite functional thin film, wherein the thin film serves as a dielectric layer in an inter-chip bonding layer or a redistribution layer, or as a substrate dielectric layer for integrating passive devices.

[0022] The present application adopts the above technical solution, and its beneficial effects are as follows: The composite functional thin film provided in this application comprises at least two functional layers, wherein the layer directly contacts the surface of the active region of the semiconductor as an interface passivation layer; and the layer above the interface passivation layer is a composite heat dissipation functional layer, which uses a dielectric material as a matrix and uniformly disperses highly thermally conductive insulating nanofillers in the matrix to form a thermally conductive path through the composite heat dissipation functional layer. This application transforms the passivation layer from a "thermal insulator" into a "thermal pathway," directly and efficiently dissipating heat from the heat source (channel), fundamentally reducing the channel operating temperature. Through this integrated structure, "low interface state" and "high heat dissipation capability" are simultaneously achieved, ensuring that the device not only performs well under static or small signal conditions, but also maintains high output power, high efficiency, and low dynamic resistance under actual high-power RF operating conditions, eliminating performance degradation caused by self-heating. This enables the device to operate safely and stably at higher power densities, thereby fully releasing the performance advantages of GaN materials. Furthermore, since the core heat dissipation problem has been solved in the front-end process, it may reduce the dependence on complex and expensive back-end heat dissipation solutions (such as TSV), which helps to simplify system design and reduce costs. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art 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 This is a schematic diagram of the structure of a composite functional thin film for semiconductor devices provided in an embodiment of this application. Detailed Implementation

[0025] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0027] Please see Figure 1 This invention provides a composite functional thin film for semiconductor devices. The thin film includes at least two functional layers, wherein the layer directly in contact with the surface of the active region of the semiconductor is an interface passivation layer 10; and the layer above the interface passivation layer 10 is a composite heat dissipation functional layer 20, which uses a dielectric material as a matrix and uniformly disperses highly thermally conductive insulating nanofillers in the matrix to form a heat conduction path through the composite heat dissipation functional layer 20. The specific implementation of each component is described in detail below.

[0028] It is understandable that the core mission of the interface passivation layer 10, as the direct contact layer with the GaN surface, is to achieve excellent electrical passivation by significantly reducing the interface state density through saturated surface dangling bonds, thereby suppressing the current collapse effect. At the same time, its low-damage deposition characteristics protect the sensitive GaN surface.

[0029] In this embodiment, the interface passivation layer 10 is preferably silicon-rich silicon nitride or silicon oxynitride, with silicon-rich silicon nitride having a higher silicon atomic ratio than the standard stoichiometric Si3N4. The excess silicon atoms effectively passivate the nitrogen dangling bonds on the GaN surface, reducing the target interface density of states (Dit) to 1 × 10¹² cm⁻¹. - ² eV - ¹ The introduction of oxygen in silicon nitride can further adjust the band alignment and interfacial stress with GaN, thereby achieving more optimized electrical stability. Furthermore, the thickness of the interface passivation layer is controlled in the range of 5-15 nm, which is sufficient to form an effective passivation interface while being thin enough to minimize its contribution to the overall thermal resistance; the refractive index is controlled in the range of 2.10 to 2.50, which is higher than the refractive index range of standard SiN (~2.0), providing direct evidence of silicon-rich composition and a key process control indicator.

[0030] In this embodiment, the matrix is ​​silicon nitride (Si3N4) at or near stoichiometric ratio. It provides mechanical support, electrical insulation, and good adhesion to the upper and lower layers. The highly thermally conductive insulating nanofiller is selected from one or more of the following: aluminum nitride nanowires, boron nitride nanosheets, graphene nanosheets, diamond nanoparticles, and alumina nanoparticles, or a mixture thereof.

[0031] Preferably, the high thermal conductivity insulating nanofiller is AlN nanowire. Single-crystal AlN nanowires have extremely high thermal conductivity along the axial direction (~200-320 W / mK) and are themselves insulators, exhibiting excellent compatibility with semiconductor processes. Preferably, the high thermal conductivity insulating nanofiller is BN nanosheets, which have extremely high in-plane thermal conductivity (~300-600 W / mK), and their sheet-like structure easily forms a thermally conductive network in the planar direction. To ensure uniform dispersion of the nanofiller and enhance its interfacial bonding with the SiN matrix, surface functionalization treatment is required. For example, AlN nanofillers can be treated with a silane coupling agent (such as APTES) to imbue their surface with functional groups capable of forming strong chemical bonds with the SiN matrix.

[0032] Furthermore, the thickness of the composite heat dissipation functional layer 20 is controlled within the range of 50-200 nm. This thickness provides sufficient volume to accommodate an effective heat conduction path without affecting the miniaturization of the device. The filler volumetricity is controlled at 25% ± 3%; too low a volumetricity results in insignificant thermal enhancement, while too high a volumetricity may affect the film's density, insulation, and mechanical strength. Filler orientation: through process control, the nanowires / nanofa are preferably oriented to a certain extent perpendicular to the substrate direction to maximize the vertical thermal conductivity. Testing shows that the overall longitudinal thermal conductivity of this composite layer is 3-8 times higher than that of traditional SiN.

[0033] It should be noted that the filler needs to undergo surface functionalization treatment to improve its dispersibility and interfacial adhesion in the matrix. Electrically, it serves as an extension of the main passivation layer, maintaining insulation and passivation properties. Thermally, it forms a three-dimensional thermally conductive network in the SiN matrix, constructing an efficient heat dissipation path from the channel upwards, significantly improving the longitudinal thermal conductivity of the film (100 nm thickness). The volume doping ratio of the nanofiller is 25% ± 3%. Through process control, the nanowires / nanofa sheets can be optimized to exhibit a certain degree of vertical orientation to maximize the vertical thermal conductivity.

[0034] Furthermore, the volume doping ratio of the highly thermally conductive insulating nanofiller in the composite heat dissipation functional layer is 15% to 35%. Preferably, the volume doping ratio is 22% to 28%.

[0035] It is understandable that if the volume doping ratio of the nanofiller is precisely controlled at this ratio, the longitudinal thermal conductivity of the composite layer can be increased by 3-8 times compared to that of pure SiN film, for example, from ~2 W / mK to 8-16 W / mK.

[0036] Furthermore, the high thermal conductivity insulating nanofiller has a preferred orientation perpendicular to the surface of the semiconductor active region in the composite heat dissipation functional layer to maximize the thermal conductivity in the vertical direction.

[0037] Furthermore, the thin film comprises, from bottom to top, the interface passivation layer 10, the composite heat dissipation functional layer 20, and the uppermost dense protective layer 30, wherein the material of the dense protective layer 30 is a nitrogen-rich nitride or oxide.

[0038] In this embodiment, the thickness of the dense protective layer 30 is 20-60 nm.

[0039] The dense protective layer material uses stoichiometric or slightly nitrogen-rich silicon nitride to provide dense surface protection, exhibiting excellent resistance to moisture and ion contamination. It can also serve as a hard mask and mechanical protective layer for subsequent processes such as photolithography and metal wiring. Its inherent compressive stress also helps balance the stress throughout the stack (40 nm thick), reducing wafer warpage.

[0040] Furthermore, between the interface passivation layer 10 and the composite heat dissipation functional layer 20, there is also an ultrathin oxide layer 40 formed by atomic layer deposition technology, with a thickness of less than 5 nm.

[0041] In this embodiment, an ultrathin (<5nm) ALD (atomic layer deposition) alumina (Al2O3) layer is added between the interface passivation layer and the composite heat dissipation functional layer. This layer provides an extreme interface passivation effect, complementing the SiN layer and further reducing the interface state. The entire structure becomes: GaN / ALD-Al2O3 / interface SiN layer / composite heat dissipation layer / dense capping layer.

[0042] Furthermore, the interface layer can use high-k dielectrics such as Al2O3 and HfO2 deposited by ALD to achieve the ultimate interface quality. The capping layer can use silicon dioxide or carbon-doped silicon nitride to meet different stress control and etching selectivity requirements.

[0043] The composite functional thin film provided in this application comprises at least two functional layers, wherein the layer directly contacts the surface of the active region of the semiconductor as an interface passivation layer; and the layer above the interface passivation layer is a composite heat dissipation functional layer, which uses a dielectric material as a matrix and uniformly disperses highly thermally conductive insulating nanofillers in the matrix to form a thermally conductive path through the composite heat dissipation functional layer. This application transforms the passivation layer from a "thermal insulator" into a "thermal pathway," directly and efficiently dissipating heat from the heat source (channel), fundamentally reducing the channel operating temperature. Through this integrated structure, "low interface state" and "high heat dissipation capability" are simultaneously achieved, ensuring that the device not only performs well under static or small signal conditions, but also maintains high output power, high efficiency, and low dynamic resistance under actual high-power RF operating conditions, eliminating performance degradation caused by self-heating. This enables the device to operate safely and stably at higher power densities, thereby fully releasing the performance advantages of GaN materials. Furthermore, since the core heat dissipation problem has been solved in the front-end process, it may reduce the dependence on complex and expensive back-end heat dissipation solutions (such as TSV), which helps to simplify system design and reduce costs.

[0044] This application also provides a method for preparing the composite functional thin film, comprising the following steps: forming a silicon-rich interface passivation layer on the surface of a semiconductor active region by a low-damage plasma-enhanced chemical vapor deposition process; and simultaneously depositing a dielectric matrix on the interface passivation layer by a hybrid deposition process and introducing and oriented highly thermally conductive insulating nanofillers in situ to form the composite heat dissipation functional layer.

[0045] In this embodiment, on a GaN-on-SiC wafer with source, gate, and drain electrodes fabricated, plasma-enhanced chemical vapor deposition is used to deposit a silicon-rich silicon nitride interface layer at 300-400°C by introducing a high flow rate of silane and a low flow rate of ammonia at a low radio frequency power.

[0046] Specifically, the GaN-on-SiC wafer with completed electrode fabrication was placed in a PECVD reaction chamber, with the chamber temperature set at 300°C. Reaction gases, silane (SiH4) and ammonia (NH3), were introduced, with nitrogen (N2) used as the carrier gas. By setting a high SiH4 / NH3 flow rate (5:1) and using a low RF power (50), a 10 nm silicon-rich silicon nitride layer was deposited under low pressure. Ellipsometry measurements were used, and deposition was stopped when the refractive index reached the target range of 2.10–2.50.

[0047] Furthermore, a hybrid deposition method combining PECVD and micro-area evaporation assembly is employed to uniformly disperse surface-functionalized AlN nanowires or BN nanosheets in a volatile solvent to form an aerosol. Within the PECVD reaction chamber, while depositing a standard SiN matrix, the aerosol is introduced in situ into the reaction chamber. By controlling the airflow direction and electric field within the reaction chamber, the anisotropic nanowires / nanofashes are subjected to directional forces during the deposition process, thereby achieving a partially vertically oriented distribution in the SiN film. By controlling the precursor ratio and deposition time, the filler concentration and the thickness of the functional layer can be precisely controlled.

[0048] Specifically, a hybrid deposition method combining PECVD and aerosol-assisted directional assembly is employed. First, aerosol preparation involves dispersing surface-functionalized AlN nanowires or BN nanosheets in a volatile organic solvent (such as isopropanol). This is followed by ultrasonic disruption and atomization to form a uniform and stable nanofiller aerosol. Next, hybrid deposition and directional assembly occur. After depositing the interface layer, without disrupting the vacuum in the PECVD reaction chamber, the precursors (SiH4, NH3) of the standard SiN matrix are aerated, and high-frequency plasma deposition begins. Simultaneously, the prepared nanofiller aerosol is introduced in situ and controllably into the plasma region through a dedicated injection port. By precisely controlling the airflow distribution of the spray head at the top of the reaction chamber and the radio frequency electric field between the electrode plates, an directional force is applied to the anisotropic and dipole-moment nanofillers entering the plasma region, driving them to preferentially align perpendicular to the substrate during deposition. By controlling the aerosol concentration, injection rate, and deposition time, the final volume ratio of the filler in the matrix (25% ± 3%) and the total thickness of the functional layer (100 nm) are precisely controlled.

[0049] In this embodiment, the hybrid deposition process is a combination of plasma-enhanced chemical vapor deposition and aerosol-assisted directional assembly; the external directional field is an electric field, a gas flow field, or a combination thereof; or, the hybrid deposition process is a combination of sputtering deposition and ion implantation embedding.

[0050] Furthermore, a dense protective layer is deposited on the composite heat dissipation functional layer, and the material of the dense protective layer is a nitrogen-rich nitride or oxide.

[0051] Specifically, the wafer is kept in a vacuum reaction chamber, the process gas is adjusted (e.g., increasing the NH3 / SiH4 ratio), and a dense nitrogen-rich silicon nitride capping layer is directly deposited on the interface layer and functional layer using a standard PECVD process.

[0052] This application provides a method for creating a composite functional thin film, comprising the following steps: forming a silicon-rich interface passivation layer on the surface of a semiconductor active region using a low-damage plasma-enhanced chemical vapor deposition process; simultaneously depositing a dielectric matrix on the interface passivation layer using a hybrid deposition process and in-situ introducing and oriented highly thermally conductive insulating nanofillers to form the composite heat dissipation functional layer, which inherits the excellent electrical properties of traditional passivation layers while possessing a thermal conductivity far exceeding that of traditional SiN; transforming the passivation layer from a "thermal insulator" into a "thermal pathway," directly and efficiently dissipating heat from the heat source (channel), fundamentally reducing the channel operating temperature; and simultaneously achieving "low interface state" and "high heat dissipation capability" through the integrated structure. The aim is to ensure that the device not only performs well under static or small-signal conditions but also maintains high output power, high efficiency, and low dynamic resistance under actual high-power RF operating conditions, eliminating performance degradation caused by self-heating; enabling the device to operate safely and stably at higher power densities, thereby fully releasing the performance advantages of GaN materials. One side effect is that, since the core heat dissipation problem has been solved in the front-end process, it may be possible to reduce the reliance on complex and expensive back-end heat dissipation solutions (such as TSV), which can help simplify system design and reduce costs.

[0053] The composite functional thin film and its preparation method provided in this application successfully break the fundamental contradiction between "electrical passivation" and "heat dissipation" in traditional technologies by integrating "high thermal conductivity nanofillers" into "multilayer SiN passivation structures". During high-power operation, it can significantly reduce the internal temperature of the chip, thereby improving the RF output power and efficiency and fully releasing the performance potential of GaN. It fundamentally alleviates the "thermal bottleneck" that leads to device failure, greatly improving the long-term reliability and lifespan of the device. It provides a front-end, in-situ heat dissipation solution, which may simplify the design dependence on complex back-end heat dissipation and lay the foundation for manufacturing more compact and cost-effective high-performance devices.

[0054] This application also provides a semiconductor device, wherein at least one active region of the device is prepared with the aforementioned composite functional thin film.

[0055] Furthermore, the semiconductor device is a radio frequency device or a power electronic device, and its active region material is selected from gallium nitride, gallium arsenide, silicon carbide, and gallium oxide.

[0056] Specifically, the semiconductor device is a light-emitting diode or a laser diode.

[0057] For example, the semiconductor devices provided in this application are other high-frequency, high-power electronic devices, including: Silicon-based GaN devices: For cost-sensitive silicon-based GaN power and RF devices, the self-heating effect is equally severe, and this invention can be directly applied.

[0058] Gallium arsenide devices: In high-power gallium arsenide pHEMTs, there are also requirements for passivation and heat dissipation. This invention can improve their power density.

[0059] Ultra-wide bandgap devices such as graphene and gallium oxide: These next-generation semiconductor materials have different thermal conductivity, but they all face the challenge of heat dissipation under high power density. This invention can serve as the core passivation heat dissipation technology.

[0060] For example, the semiconductor device provided in this application is a power electronic device, including: GaN power switching devices: GaN power ICs used in fast charging, data centers, and new energy vehicles also suffer from self-heating effects in terms of efficiency and reliability. The thin film structure of this invention can be used as a passivation layer for the device, or embedded as a dielectric layer in thermal vias, directly improving the heat dissipation capacity of the overall module.

[0061] Silicon carbide power MOSFETs: Although SiC MOSFETs have good thermal conductivity, their gate oxide interface and passivation layer remain crucial to their reliability. This invention can be used to optimize their gate oxide reliability and surface passivation, while also aiding in heat dissipation.

[0062] For example, the semiconductor devices provided in this application are optoelectronic integration devices and LEDs, including: High-power laser diodes: Cavity surface temperature and reliability are key issues for lasers. This invention can serve as a passivation and heat dissipation composite layer on the laser end face, effectively reducing operating temperature and extending lifespan.

[0063] Micro-LED Displays: One of the core challenges facing Micro-LEDs is the "sharp drop in efficiency," partly due to the self-heating effect at high current densities. This invention can serve as a sidewall passivation layer for Micro-LED pixels, providing electrical isolation while efficiently dissipating heat, thus improving luminous efficiency and uniformity.

[0064] For example, the semiconductor device provided in this application is an advanced packaged and integrated device, including: Inter-chip dielectric layer: In 2.5D / 3D advanced packaging, the heat generated by chip stacking is a major challenge. The "thermally conductive dielectric" concept described in this invention can be used to fabricate inter-chip bonding layers or dielectric layers with high thermal conductivity, becoming an efficient thermal management path in the vertical direction.

[0065] Integrated passive components: High-performance MIM capacitors or inductors can be directly fabricated on a high thermal conductivity composite dielectric layer, reducing the impact of thermal effects on the performance of passive components.

[0066] This application also provides an electronic packaging structure comprising the aforementioned composite functional thin film, wherein the thin film serves as a dielectric layer in an inter-chip bonding layer, a redistribution layer, or a substrate dielectric layer for integrating passive devices.

[0067] The electronic packaging structure provided in this application includes the aforementioned composite functional thin film. This thin film serves as a dielectric layer in inter-chip bonding layers, redistribution layers, or a substrate dielectric layer for integrated passive devices. It transforms the passivation layer from a "thermal insulator" into a "thermal pathway," directly and efficiently dissipating heat from the heat source (channel), fundamentally reducing the channel operating temperature. Through this integrated structure, "low interface state" and "high heat dissipation capability" are simultaneously achieved, ensuring that the device not only performs well under static or small-signal conditions but also maintains high output power, high efficiency, and low dynamic resistance under actual high-power RF operating conditions, eliminating performance degradation caused by self-heating. This allows the device to operate safely and stably at higher power densities, thereby fully releasing the performance advantages of GaN materials. Furthermore, since the core heat dissipation problem has been solved in the front-end process, it may reduce reliance on complex and expensive back-end heat dissipation solutions (such as TSVs), helping to simplify system design and reduce costs.

[0068] It is understood that the technical features of the above embodiments can be combined arbitrarily. 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.

[0069] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A composite functional thin film for semiconductor devices, characterized in that, The thin film comprises at least two functional layers, wherein the layer directly in contact with the surface of the active region of the semiconductor is an interface passivation layer; and the layer above the interface passivation layer is a composite heat dissipation functional layer, which is based on a dielectric material and has highly thermally conductive insulating nanofillers uniformly dispersed in the matrix to form a heat conduction path through the composite heat dissipation functional layer.

2. The composite functional film according to claim 1, characterized in that, The thin film comprises, from bottom to top, the interface passivation layer, the composite heat dissipation functional layer, and the uppermost dense protective layer, wherein the material of the dense protective layer is a nitrogen-rich nitride or oxide.

3. The composite functional film according to claim 2, characterized in that, Between the interface passivation layer and the composite heat dissipation functional layer, there is also an ultrathin oxide layer formed by atomic layer deposition technology, with a thickness of less than 5 nm.

4. The composite functional film according to claim 1 or 2, characterized in that, The high thermal conductivity insulating nanofiller is selected from one or more of the following: aluminum nitride nanowires, boron nitride nanosheets, graphene nanosheets, diamond nanoparticles, and alumina nanoparticles, or a mixture thereof.

5. The composite functional film according to claim 4, characterized in that, The volume doping ratio of the high thermal conductivity insulating nanofiller in the composite heat dissipation functional layer is 15% to 35%.

6. The composite functional film according to claim 5, characterized in that, The volume doping ratio is 22% to 28%.

7. The composite functional film according to claim 1 or 2, characterized in that, The highly thermally conductive insulating nanofiller has a preferred orientation perpendicular to the surface of the semiconductor active region in the composite heat dissipation functional layer.

8. The composite functional film according to claim 2, characterized in that, The material of the interface passivation layer is silicon-rich silicon nitride or silicon oxynitride, with a refractive index of 2.10 to 2.50; the matrix of the composite heat dissipation functional layer is silicon nitride; and the material of the dense protective layer is nitrogen-rich silicon nitride.

9. The composite functional film according to claim 8, characterized in that, The thickness of the interface passivation layer is 5-15 nm, the thickness of the composite heat dissipation functional layer is 50-200 nm, and the thickness of the dense protective layer is 20-60 nm.

10. A method for preparing a composite functional thin film as described in any one of claims 1-9, characterized in that, The process includes the following steps: forming a silicon-rich interface passivation layer on the surface of the active region of a semiconductor using a low-damage plasma-enhanced chemical vapor deposition process; and simultaneously depositing a dielectric matrix on the interface passivation layer using a hybrid deposition process and introducing and oriented highly thermally conductive insulating nanofillers in situ to form the composite heat dissipation functional layer.

11. The method according to claim 10, characterized in that, The hybrid deposition process combines plasma-enhanced chemical vapor deposition with aerosol-assisted directional assembly; the external directional field is an electric field, a gas flow field, or a combination thereof.

12. The method according to claim 10, characterized in that, The hybrid deposition process combines sputtering deposition with ion implantation embedding.

13. The method according to claim 10, characterized in that, A dense protective layer is deposited on the composite heat dissipation functional layer, and the material of the dense protective layer is a nitrogen-rich nitride or oxide.

14. A semiconductor device, characterized in that, At least one active region surface of the device is prepared with a composite functional thin film as described in any one of claims 1-9.

15. The semiconductor device according to claim 14, characterized in that, The semiconductor device is a radio frequency device or a power electronic device, and its active region material is selected from gallium nitride, gallium arsenide, silicon carbide, and gallium oxide.

16. The semiconductor device according to claim 14, characterized in that, The semiconductor device is a light-emitting diode or a laser diode.

17. An electronic packaging structure, characterized in that, The invention comprises a composite functional thin film as described in any one of claims 1-9, wherein the thin film serves as a dielectric layer in an inter-chip bonding layer, a redistribution layer, or a substrate dielectric layer for integrating passive devices.

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