Radio frequency front-end module, radio frequency terminal and preparation method of radio frequency front-end module

Abstract

The invention relates to the technical field of semiconductors, and discloses a radio frequency front-end module, a radio frequency terminal and a preparation method thereof, and the radio frequency front-end module comprises a base substrate which is provided with a first surface and a second surface which are opposite to each other; the first epitaxial layer is arranged on the first surface, and the material type of the first epitaxial layer is matched with the device type of the first device, so that the surface, away from the basic substrate, of the first epitaxial layer is suitable for arranging the first device; the second epitaxial layer is arranged on the second surface, and the material type of the second epitaxial layer is matched with the device type of the second device, so that the surface, away from the basic substrate, of the second epitaxial layer is suitable for arranging the second device; the first epitaxial layer, the second epitaxial layer and the basic substrate are different in material type, and the device type of the first device is different from that of the second device. The radio frequency front-end module has the beneficial effects that the device integration level in the radio frequency front-end module is effectively improved, and the size of the radio frequency front-end module is remarkably reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a radio frequency front-end module, a radio frequency terminal, and a method for manufacturing the same. Background Art

[0002] With the rapid development of wireless communication technology, the complexity of transmitted signals continues to increase. To effectively transmit, receive, and process these complex signals, RF front-end modules (RFFEMs) must possess more functions to meet the needs of signal transmission. This places higher demands on the functional integration of RFFEMs. To achieve these multiple functions, RFFEMs integrate a variety of components, including signal amplifiers, duplexers, filters, and RF switches. However, due to processing technology and size limitations, these components occupy a large amount of space within the RFFEM, further limiting its miniaturization.

[0003] In related technologies, the device integration level of RF front-end modules still needs to be improved. Summary of the Invention

[0004] The present application provides a radio frequency front-end module, a radio frequency terminal, and a method for preparing the same, in which epitaxial layers of different materials are integrated on the two surfaces of a base substrate, respectively, and the material types of the epitaxial layers match the different device types, thereby enabling the integration of various types of devices on the surface of the epitaxial layers, effectively improving the device integration level in the radio frequency front-end module and significantly reducing the size of the radio frequency front-end module.

[0005] In order to achieve the above objectives, the main technical solutions adopted in this application include:

[0006] In a first aspect, an embodiment of the present application provides a radio frequency front-end module, comprising:

[0007] a base substrate having opposing first and second surfaces;

[0008] a first epitaxial layer, the first epitaxial layer being disposed on the first surface, the material type of the first epitaxial layer matching the device type of the first device, so that the surface of the first epitaxial layer away from the base substrate is suitable for arranging the first device;

[0009] a second epitaxial layer, the second epitaxial layer being disposed on the second surface, wherein a material type of the second epitaxial layer matches a device type of the second device, so that a surface of the second epitaxial layer away from the base substrate is suitable for disposing the second device;

[0010] The material type of the first epitaxial layer is different from the material type of the base substrate, the material type of the second epitaxial layer is different from the material type of the base substrate, the material type of the first epitaxial layer is different from the material type of the second epitaxial layer, and the device type of the first device is different from the device type of the second device.

[0011] The RF front-end module proposed in the embodiment of the present application integrates a first epitaxial layer on the first surface of the base substrate, and integrates a second epitaxial layer of a different material on the opposite second surface, thereby realizing multi-material epitaxial layer integration on the base substrate; and the material types of the first epitaxial layer and the second epitaxial layer are matched with different device types, so that the surfaces of the first epitaxial layer and the second epitaxial layer can be respectively provided with devices of different device types, thereby realizing multi-device integration suitable for different epitaxial layer materials in the RF front-end module, significantly improving the device integration level in the RF front-end module. By integrating multi-material epitaxial layers and multiple devices suitable for different epitaxial layer materials into the RF front-end module, the present application reduces the area of ​​the RF front-end module by half compared with the related technologies, and significantly increases the number of devices that can be integrated in the same RF front-end module, effectively improving the device integration level in the RF front-end module, thereby being able to adapt to the requirements of wireless communication technology for multi-functional communication.

[0012] Optionally, there are multiple first devices, and the first devices are electrically connected to each other via a first signal line, and the first signal line is provided on a surface of the first epitaxial layer away from the base substrate;

[0013] The plurality of first components and the first signal traces are all obtained by processing through the same photomask.

[0014] Optionally, there are multiple second devices, and the second devices are electrically connected to each other via a second signal line, and the second signal line is provided on a surface of the second epitaxial layer away from the base substrate;

[0015] The plurality of second devices and the second signal traces are all obtained by processing through the same photomask.

[0016] Optionally, conductive vias are provided through the base substrate, the first epitaxial layer, and the second epitaxial layer, and the first device and the second device are electrically connected through the conductive vias.

[0017] Optionally, a surface of the first epitaxial layer away from the base substrate is provided with a first protective layer wrapping the first device, and a surface of the second epitaxial layer away from the base substrate is provided with a second protective layer wrapping the second device;

[0018] The RF front-end module further includes a connection interface, which is provided on a surface of the first protective layer or the second protective layer away from the base substrate.

[0019] Optionally, a first buffer layer is provided between the first epitaxial layer and the base substrate, and a second buffer layer is provided between the second epitaxial layer and the base substrate.

[0020] Optionally, the first epitaxial layer is a single crystal silicon thin film, and the device types of the first device include signal amplifiers, radio frequency switches and passive devices.

[0021] Optionally, the second epitaxial layer is a piezoelectric film, and the device types of the second device include a duplexer and a filter.

[0022] In a second aspect, an embodiment of the present application provides a radio frequency terminal, which includes the radio frequency front-end module described in any one of the above embodiments.

[0023] In a third aspect, an embodiment of the present application provides a method for preparing a radio frequency front-end module, the method comprising:

[0024] Providing a base substrate, forming a first epitaxial layer on a first surface of the base substrate, and forming a second epitaxial layer on a second surface of the base substrate; wherein the material type of the first epitaxial layer is different from the material type of the base substrate, the material type of the second epitaxial layer is different from the material type of the base substrate, and the material type of the first epitaxial layer is different from the material type of the second epitaxial layer;

[0025] Using a first photomask, etching a surface of the first epitaxial layer away from the base substrate to form a first device; wherein the device type of the first device matches the material type of the first epitaxial layer;

[0026] Using a second photomask, etching a surface of the second epitaxial layer away from the base substrate to form a second device; wherein the device type of the second device matches the material type of the second epitaxial layer;

[0027] A first protective layer is formed around the first device, and a second protective layer is formed around the second device; a connection interface is made on the surface of the first protective layer or the second protective layer away from the base substrate to obtain a radio frequency front-end module. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0029] Figure 1 Schematic diagram of the signal transmission link within the RF front-end module in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of the structure of the radio frequency front-end module provided in an embodiment of the present application;

[0031] Figure 3a Schematic diagram of the structure of a single crystal silicon substrate;

[0032] Figure 3b Schematic diagram of the structure of a piezoelectric material substrate;

[0033] Figure 3c Schematic diagram of the structure of a gallium arsenide substrate alone;

[0034] Figure 4 Schematic diagram of a module structure including a first device and a second device in an embodiment of the present application;

[0035] Figure 5 Schematic diagram of a device obtained by photomask processing in an embodiment of the present application;

[0036] Figure 6 This is a schematic diagram of the structure of the radio frequency front-end module in an embodiment of the present application;

[0037] Figure 7 A diagram showing the steps of a method for preparing a radio frequency front-end module according to an embodiment of the present application;

[0038] Figure 8a This is a schematic diagram of the first process of the preparation method in the embodiment of the present application;

[0039] Figure 8b This is a second flow chart of the preparation method in the embodiment of the present application;

[0040] Figure 8c This is a third flow chart of the preparation method in the examples of this application.

[0041] Among them, the figure numbers of the drawings in the specification are as follows: 100, base substrate, 110, conductive through hole, 200, first epitaxial layer, 210, first device, 211, transistor, 212, metal wiring, 213, passive device, 220, first signal line, 230, first protective layer, 240, first buffer layer, 300, second epitaxial layer, 310, second device, 311, filter fork finger, 320, second signal line, 330, second protective layer, 340, second buffer layer, 400, connection interface. DETAILED DESCRIPTION

[0042] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings provide embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0044] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or there can be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types, and / or portions, these elements, components, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, doping type, or portion from another element, component, region, layer, doping type, or portion. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer, doping type or portion discussed below may be represented as a second element, component, region, layer or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0045] Spatially relative terms such as "under," "beneath," "beneath," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, spatially relative terms also include different orientations of the device in use and operation. For example, if the device in the drawings is turned over, the element or feature described as "under" or "beneath" or "beneath" the other elements will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" can include both upper and lower orientations. In addition, the device can also include alternative orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0046] As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include," "comprising," "having," and the like specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. Also, in this specification, the term "and / or" includes any and all combinations of the relevant listed items.

[0047] With the rapid development of wireless communication technology, the complexity of transmission signals in the communication process continues to increase. In order to effectively transmit, receive and process these complex transmission signals, the RF front-end module needs to have more functions to adapt to the needs of signal transmission, which puts higher requirements on the functional integration of the RF front-end module.

[0048] Reference Figure 1 As shown, in order to achieve multiple functions, the RF front-end module integrates various types of devices, including signal amplifiers, duplexers, filters, and RF switches. These devices need to be processed separately on the surface of substrates of different materials during the processing process, and different processing techniques are used to obtain the finished device. In the related art, the device processing process usually includes: providing a suitable separate substrate for each device, and processing each device separately on the surface of each separate substrate to obtain a device chip; finally, the device chip is mounted on the surface of the mainboard, or packaged in the same module through system packaging technology (SiP), thereby obtaining the RF front-end module. However, in actual situations, the separately processed device chips occupy a large amount of space inside the RF front-end module, resulting in the inability to reduce the size of the RF front-end module, which limits the miniaturization of the RF front-end module. In addition, the separate processing of each device increases the complexity of the processing process, while increasing the processing cost and affecting the production efficiency of the RF front-end module.

[0049] Based on the above problems, the present application provides a radio frequency front-end module, a radio frequency terminal and a preparation method thereof, including: a base substrate having a first surface and a second surface relative to each other; a first epitaxial layer is arranged on the first surface, and the material type of the first epitaxial layer matches the device type of the first device, so that the surface of the first epitaxial layer away from the base substrate is suitable for setting the first device; a second epitaxial layer is arranged on the second surface, and the material type of the second epitaxial layer matches the device type of the second device, so that the surface of the second epitaxial layer away from the base substrate is suitable for setting the second device; the material type of the first epitaxial layer is different from the material type of the base substrate, the material type of the second epitaxial layer is different from the material type of the base substrate, the material type of the first epitaxial layer is different from the material type of the second epitaxial layer, and the device type of the first device is different from the device type of the second device.

[0050] The RF front-end module provided in the present application integrates a first epitaxial layer on the first surface of a base substrate, and integrates a second epitaxial layer of a different material on the opposite second surface, thereby realizing multi-material epitaxial layer integration on the base substrate; and the material types of the first epitaxial layer and the second epitaxial layer are respectively matched with different device types, so that devices of different device types can be respectively set on the surfaces of the first epitaxial layer and the second epitaxial layer, thereby realizing multi-device integration suitable for different epitaxial layer materials in the RF front-end module, significantly improving the device integration level in the RF front-end module.

[0051] This application integrates multi-material epitaxial layers and multiple devices suitable for different epitaxial layer materials into the RF front-end module, so that the area of ​​the RF front-end module is reduced by half compared with the related technologies, and the number of devices that can be integrated in the same RF front-end module is significantly increased, effectively improving the degree of device integration in the RF front-end module, thereby being able to adapt to the needs of wireless communication technology for multi-functional communication.

[0052] The RF front-end module provided in this specification can be applied to RF terminals suitable for wireless communication technology, including but not limited to laptops, desktop computers, smartphones, smart wearable devices (virtual reality glasses, smart watches, etc.), and tablet computers. It is understood that after adaptive modification, this application can also be used in other fields that require miniaturization of RF front-end modules, such as data center servers and edge computing devices.

[0053] Embodiments of the invention are described herein with reference to cross-sectional views which are schematic illustrations of idealized embodiments (and intermediate structures) of the invention, such that variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances are anticipated. Accordingly, embodiments of the invention should not be limited to the specific shapes of the regions shown herein, but rather include deviations in shapes due to, for example, manufacturing techniques. For example, an implanted region shown as a rectangle typically has rounded or curved features and / or an implant concentration gradient at its edges rather than a binary change from an implanted region to a non-implanted region. Similarly, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation occurs. Accordingly, the regions shown in the figures are schematic in nature, their shapes do not represent the actual shape of the region of the device, and do not limit the scope of the invention.

[0054] In this embodiment, a radio frequency front-end module is provided, which can be used in the above radio frequency terminal. Figure 2 As shown, the RF front-end module includes: a base substrate having a first surface and a second surface relative to each other; a first epitaxial layer is arranged on the first surface, and the material type of the first epitaxial layer matches the device type of the first device, so that the surface of the first epitaxial layer away from the base substrate is suitable for setting the first device; a second epitaxial layer is arranged on the second surface, and the material type of the second epitaxial layer matches the device type of the second device, so that the surface of the second epitaxial layer away from the base substrate is suitable for setting the second device; the material type of the first epitaxial layer is different from the material type of the base substrate, the material type of the second epitaxial layer is different from the material type of the base substrate, the material type of the first epitaxial layer is different from the material type of the second epitaxial layer, and the device type of the first device is different from the device type of the second device.

[0055] Specifically, the RF front-end module includes a base substrate 100, a first epitaxial layer 200, and a second epitaxial layer 300, and the first epitaxial layer 200 and the second epitaxial layer 300 are respectively arranged on different surfaces of the base substrate 100. The base substrate 100 can be made of materials such as silicon, glass, quartz or ceramics. Using relatively conventional materials to support the base substrate 100 can reduce the processing cost of the RF front-end module while also having mass production capabilities. The base substrate 100 serves as the main supporting structure of the RF front-end module. It has a first surface and a second surface relative to each other, wherein the first surface is used to set the first epitaxial layer 200 and provide support for the first epitaxial layer 200 and the first device 210; the second surface is used to set the second epitaxial layer 300 and provide support for the second epitaxial layer 300 and the second device 310.

[0056] Furthermore, the first epitaxial layer 200 is provided on the first surface of the base substrate 100, and the material type of the first epitaxial layer 200 is different from the material type of the base substrate 100. It should be noted that the material type of the first epitaxial layer 200 can be determined based on the functional requirements of the RF front-end module, the device type of the first device 210 is determined according to the functional requirements of the RF front-end module, and the material type is matched according to the device type of the first device 210 to determine the material type of the first epitaxial layer 200. It is understandable that the material type of the first epitaxial layer 200 matches the device type of the first device 210, so that the first epitaxial layer 200 is suitable for providing the first device 210, so that the first device 210 can be provided on the surface of the first epitaxial layer 200 to integrate the first device 210 into the RF front-end module.

[0057] Furthermore, similar to the first epitaxial layer 200, the second epitaxial layer 300 is provided on the first surface of the base substrate 100, and the material type of the second epitaxial layer 300 is different from the material type of the base substrate 100. It should be noted that the material type of the second epitaxial layer 300 can be determined based on the functional requirements of the RF front-end module, the device type of the second device 310 is determined according to the functional requirements of the RF front-end module, and the material type is matched according to the device type of the second device 310 to determine the material type of the second epitaxial layer 300. It is understandable that the material type of the second epitaxial layer 300 matches the device type of the second device 310, making the second epitaxial layer 300 suitable for providing the second device 310, so that the second device 310 can be provided on the surface of the second epitaxial layer 300 to integrate the second device 310 into the RF front-end module.

[0058] Furthermore, the material type of the first epitaxial layer 200 is different from the material type of the second epitaxial layer 300. Exemplarily illustrating the material type of the epitaxial layer, the material type of the first epitaxial layer 200 and the second epitaxial layer 300 can be any of single crystal silicon, piezoelectric material and gallium arsenide. Among them, when the material of the epitaxial layer is single crystal silicon, it forms an insulating silicon (Silicon on Insulator, SOI) substrate on the surface of the base substrate 100. The structure of the conventional insulating silicon substrate is referred to as Figure 3a As shown, the structure consists of a vertically stacked high-resistance silicon substrate, a buried oxide layer, and a single-crystal silicon layer. The high-resistance silicon substrate provides support for the buried oxide layer and the single-crystal silicon layer; the buried oxide layer provides electrical isolation between the high-resistance silicon substrate and the single-crystal silicon layer; and the single-crystal silicon layer is used to construct devices on the substrate surface. Devices suitable for insulating silicon substrates include radio frequency switches and low-noise amplifiers.

[0059] When the epitaxial layer is made of piezoelectric material, a piezoelectric (Porous Silicon on Insulator, POI) substrate is formed on the surface of the base substrate 100. The structure of the conventional piezoelectric substrate is similar to that of the conventional piezoelectric substrate. Figure 3b As shown, the device consists of a vertically stacked high-resistance silicon substrate, a buried oxide layer, and a single-crystal piezoelectric layer. The high-resistance silicon substrate provides support for the buried oxide layer and the single-crystal piezoelectric layer; the buried oxide layer provides electrical isolation between the high-resistance silicon substrate and the single-crystal piezoelectric layer; and the single-crystal piezoelectric layer is used to construct devices on the substrate surface. Devices suitable for piezoelectric substrates include duplexers and filters.

[0060] When the epitaxial layer is made of gallium arsenide, a gallium arsenide (GaAs) substrate is formed on the surface of the base substrate 100. The structure of the conventional gallium arsenide substrate is as follows: Figure 3c As shown, the GaAs substrate comprises a GaAs substrate, a GaAs epitaxial layer, and multiple GaAs doped layers stacked vertically. The GaAs substrate provides support for the GaAs epitaxial layer and the multiple GaAs doped layers. The GaAs epitaxial layer adjusts the lattice matching between the multiple GaAs doped layers and the GaAs substrate, improving the reliability of devices on the GaAs substrate surface. The multiple GaAs doped layers form specific functional structures to construct devices. Devices suitable for GaAs substrates include power amplifiers.

[0061] When the material of the base substrate is glass, among the above-mentioned epitaxial layer materials, the single crystal silicon epitaxial layer and the piezoelectric epitaxial layer can be directly integrated with the base substrate 100, but the lattice mismatch between gallium arsenide and the base substrate 100 is large, resulting in lower effectiveness of the integration of the gallium arsenide substrate and the base substrate 100 compared with the insulating silicon substrate and the piezoelectric substrate. It may be necessary to set a buffer layer between the gallium arsenide substrate and the base substrate 100 for adaptation.

[0062] It should be noted that the material type of the first epitaxial layer 200 is different from the material type of the second epitaxial layer 300, so the device type of the first device 210 is also different from the device type of the second device 310, that is, the first device 210 and the second device 310 can respectively realize different functions, such as signal transmission, signal reception and power amplification, etc., thereby integrating multiple functions into the interior of the RF front-end module to meet the multifunctional requirements of the RF front-end module. In addition, the first epitaxial layer 200 and the second epitaxial layer 300 are respectively located on two opposite surfaces of the base substrate 100, and both fully utilize the space on different surfaces of the base substrate 100, effectively reducing the internal space occupied by the device in the RF front-end module, so that the area of ​​the RF front-end module can be reduced by half, significantly reducing the size of the RF front-end module.

[0063] The RF front-end module provided in this embodiment integrates a first epitaxial layer on the first surface of the base substrate, and integrates a second epitaxial layer of a different material on the opposite second surface, thereby realizing multi-material epitaxial layer integration on the base substrate; and the material types of the first epitaxial layer and the second epitaxial layer are respectively matched with different device types, so that devices of different device types can be respectively set on the surfaces of the first epitaxial layer and the second epitaxial layer, thereby realizing multi-device integration suitable for different epitaxial layer materials in the RF front-end module, significantly improving the device integration level in the RF front-end module.

[0064] This application integrates multi-material epitaxial layers and multiple devices suitable for different epitaxial layer materials into the RF front-end module, so that the area of ​​the RF front-end module is reduced by half compared with the related technologies, and the number of devices that can be integrated in the same RF front-end module is significantly increased, effectively improving the degree of device integration in the RF front-end module, thereby being able to adapt to the needs of wireless communication technology for multi-functional communication.

[0065] As an embodiment of the present application, there are multiple first devices, and the first devices are electrically connected through first signal lines. The first signal lines are arranged on the surface of the first epitaxial layer away from the base substrate; the multiple first devices and first signal lines are all obtained through the same mask processing.

[0066] Reference Figure 4 As shown, there may be multiple first devices 210 formed on the surface of the first epitaxial layer 200, and the device types of different first devices 210 may be different, that is, different first devices 210 may respectively implement different functions. It should be noted that the first device 210 may be provided on the surface of the first epitaxial layer 200 in the form of a device circuit. The multiple first devices 210 are distributed on the surface of the first epitaxial layer 200 away from the base substrate 100 according to the module design, and are electrically connected through the first signal traces 220, so that the first devices 210 can interact with each other, realizing multi-functional integration in the RF front-end module.

[0067] Furthermore, the material type on the surface of the first epitaxial layer 200 is consistent, so when device processing is performed on the surface of the first epitaxial layer 200 away from the base substrate 100, multiple first devices 210 and first signal traces 220 can be processed simultaneously using the same mask. Figure 5As shown, during the processing, the device type of the first device 210 is first determined based on the module design, and the distribution of the first devices 210 and the signal routing between different first devices 210 are designed to obtain a corresponding mask. Next, the obtained mask is used to expose the surface of the first epitaxial layer 200 away from the base substrate 100, thereby transferring the pre-designed device circuit pattern and the first signal routing 220 pattern to the surface of the first epitaxial layer 200 away from the base substrate 100. Then, the first devices 210 and the first signal routing 220 are formed through processes such as etching.

[0068] It should be noted that in related art, different devices are typically processed into separate device chips, each of which is processed using a separate mask, resulting in the need to design and obtain multiple different masks during the processing. In this embodiment, the surface of the first epitaxial layer 200 away from the base substrate 100 can be processed using the same mask for multiple first devices 210 and first signal traces 220, effectively reducing the number of masks required during the processing, simplifying the processing process and reducing processing costs.

[0069] As an embodiment of the present application, there are multiple second devices, and the second devices are electrically connected through second signal lines. The second signal lines are arranged on the surface of the second epitaxial layer away from the base substrate; the multiple second devices and second signal lines are all obtained through the same mask processing.

[0070] Reference Figure 4 As shown, there may be multiple second devices 310 formed on the surface of the second epitaxial layer 300, and the device types of different second devices 310 may be different, that is, different second devices 310 may respectively implement different functions. It should be noted that the second device 310 may be provided on the surface of the second epitaxial layer 300 in the form of a device circuit. The multiple second devices 310 are distributed on the surface of the second epitaxial layer 300 away from the base substrate 100 according to the module design, and are electrically connected through the second signal traces 320, so that the second devices 310 can interact with each other, realizing multi-functional integration in the RF front-end module.

[0071] Furthermore, the material type on the surface of the second epitaxial layer 300 is consistent, so when device processing is performed on the surface of the second epitaxial layer 300 away from the base substrate 100, multiple second devices 310 and second signal traces 320 can be processed simultaneously using the same mask. Figure 5As shown, during the processing, the device type of the second device 310 is first determined based on the module design, and the distribution of the second devices 310 and the signal routing between different second devices 310 are designed to obtain a corresponding mask. Next, the obtained mask is used to expose the surface of the second epitaxial layer 300 away from the base substrate 100, thereby transferring the pre-designed device circuit pattern and the second signal routing 320 pattern to the surface of the second epitaxial layer 300 away from the base substrate 100. Then, the second devices 310 and the second signal routing 320 are formed through processes such as etching.

[0072] It should be noted that in related art, different devices are typically processed into separate device chips, each of which is processed using a separate mask, resulting in the need to design and obtain multiple different masks during the processing. In this embodiment, the surface of the second epitaxial layer 300 away from the base substrate 100 can be processed using the same mask for multiple second devices 310 and second signal traces 320, effectively reducing the number of masks required during the processing, simplifying the processing and reducing processing costs.

[0073] As an embodiment of the present application, conductive vias are provided through the base substrate, the first epitaxial layer, and the second epitaxial layer, and the first device and the second device are electrically connected through the conductive vias.

[0074] Reference Figure 4 As shown, the conductive via 110 passes through the first epitaxial layer 200, the base substrate 100, and the second epitaxial layer 300, connecting the side of the first epitaxial layer 200 away from the base substrate 100 and the side of the second epitaxial layer 300 away from the base substrate 100. The conductive via 110 is filled with a metal dielectric to electrically connect the two ends of the conductive via 110. One end of the conductive via 110 is electrically connected to the first device 210 or the first signal trace 220 for electrical connection with the first device 210; the other end of the conductive via 110 is electrically connected to the second device 310 or the second signal trace 320 for electrical connection with the second device 310; thus, the first device 210 and the second device 310 are electrically connected through the conductive via 110, allowing the first device 210 and the second device 310 to interact with each other, realizing multifunctional integration in the RF front-end module.

[0075] It should be noted that due to the different material types of base substrate 100, first epitaxial layer 200, and second epitaxial layer 300, the specific forms of conductive vias 110 in different layers vary. For example, when base substrate 100 is made of glass, conductive vias 110 in base substrate 100 are through-glass vias; when the epitaxial layer is made of single-crystal silicon, conductive vias 110 in the epitaxial layer are through-silicon vias; and when the epitaxial layer is made of piezoelectric material, conductive vias 110 in the epitaxial layer are piezoelectric vias.

[0076] As an embodiment of the present application, a first protective layer wrapping the first device is provided on a surface of the first epitaxial layer away from the base substrate, and a second protective layer wrapping the second device is provided on a surface of the second epitaxial layer away from the base substrate; the RF front-end module also includes a connection interface, which is provided on the surface of the first protective layer or the second protective layer away from the base substrate.

[0077] Specifically, the material of the first protective layer 230 and the second protective layer 330 can be an insulating dielectric. The insulating dielectric is deposited and cured on the surface of the first epitaxial layer 200 away from the base substrate 100 to form an insulating dielectric layer serving as the first protective layer 230. Similarly, the insulating dielectric is deposited and cured on the surface of the second epitaxial layer 300 away from the base substrate 100 to form an insulating dielectric layer serving as the second protective layer 330. It will be appreciated that the protective layer provides physical protection for the device, while the insulating dielectric can also provide signal isolation for the device, reducing radio frequency noise interference to the device.

[0078] Furthermore, the connection interface 400 can be a pad or a bump, and the connection interface 400 is provided on the surface of the first protective layer 230 away from the base substrate 100 or on the surface of the second protective layer 330 away from the base substrate 100. When the connection interface 400 is provided on the surface of the first protective layer 230 away from the base substrate 100, it is electrically connected to the first device 210; when the connection interface 400 is provided on the surface of the second protective layer 330 away from the base substrate 100, it is electrically connected to the second device 310.

[0079] It is understandable that the surface of the connection interface 400 is also provided with a welding protection layer, which is used to protect the RF front-end module when welding the RF front-end module to the outside world, thereby reducing interference and damage to the RF front-end module during the welding process.

[0080] As an embodiment of the present application, a first buffer layer is provided between the first epitaxial layer and the base substrate, and a second buffer layer is provided between the second epitaxial layer and the base substrate.

[0081] Specifically, because the material type of the first epitaxial layer 200 is different from that of the base substrate 100, there are various differences in physical and thermal properties between the two materials, which affects the connection reliability between the first epitaxial layer 200 and the base substrate 100. These differences include differences in thermal expansion coefficients, mechanical properties, interface adhesion issues, and integration process complexity. To address these issues, a first buffer layer 240 can be provided between the first epitaxial layer 200 and the base substrate 100 to mitigate the material differences between the first epitaxial layer 200 and the base substrate 100, improve the connection reliability between the first epitaxial layer 200 and the base substrate 100, and thereby enhance the performance of the RF front-end module.

[0082] Furthermore, the material type of the first buffer layer 240 can be the same as that of the base substrate 100, thereby reducing the material difference between the first buffer layer 240 and the base substrate 100 and improving the connection reliability between the first buffer layer 240 and the base substrate 100. In addition, using the same material type to produce the first buffer layer 240 and the base substrate 100 can also improve mass production feasibility, increase production efficiency, and reduce production costs.

[0083] It is understood that the second buffer layer 340 is similar to the first buffer layer 240 .

[0084] As an embodiment of the present application, the first epitaxial layer is a single crystal silicon thin film, and the device types of the first device include a signal amplifier, a radio frequency switch, and a passive device.

[0085] Specifically, in this embodiment, the material type of the first epitaxial layer 200 can be single crystal silicon. In this case, the first epitaxial layer 200 is a single crystal silicon thin film, which forms an insulating silicon substrate on the surface of the base substrate 100. Devices suitable for the insulating silicon substrate include radio frequency switches, low noise amplifiers, power amplifiers, etc., and also include passive devices 213 such as resistors, capacitors, and inductors.

[0086] For example, referring to Figure 6 As shown, the specific structure of the first device 210 in this embodiment includes a transistor 211, at least one layer of metal wiring 212, and a passive device 213. Among them, the transistor 211 is provided on the surface of the first epitaxial layer 200 away from the base substrate 100. The gate is formed in the middle of the transistor 211, and the source and drain are formed on both sides. The transistor 211 can constitute a low-noise amplifier to achieve power amplification, or a radio frequency switch to achieve electrical connectivity control. Different transistors 211 can be electrically connected through the first signal line 220.

[0087] Metal wiring 212 may be formed on a surface of first epitaxial layer 200 away from base substrate 100 using redistribution layer (RDL) technology to electrically connect transistor 211, conductive via 110, or connection interface 400. Metal wiring 212 is embedded in an insulating dielectric to form at least one routing dielectric layer containing metal wiring 212.

[0088] Passive devices 213 are disposed in the routing dielectric layer and are electrically connected to the metal wiring 212. Passive devices 213 may be resistors or MIM capacitors (Metal-Insulator-Metal Capacitors), etc., to form functional circuits with complex functions together with the metal wiring 212.

[0089] As an embodiment of the present application, the second epitaxial layer is a piezoelectric film, and the device types of the second device include a duplexer and a filter.

[0090] Specifically, in this embodiment, the material type of the second epitaxial layer 300 can be a piezoelectric material. In this case, the second epitaxial layer 300 is a piezoelectric film, which forms a piezoelectric substrate on the surface of the base substrate 100. Devices suitable for piezoelectric substrates include duplexers and filters.

[0091] For example, referring to Figure 6 As shown, in this embodiment, the second device 310 includes a filter. The filter may include filter fingers 311 disposed on a surface of the second epitaxial layer 300 away from the base substrate 100 to perform frequency selection and filter the transmitted and received signals. The second device 310 may also include a duplexer. Different types of second devices 310 are electrically connected via second signal traces 320.

[0092] The present application also provides a radio frequency terminal, which includes the radio frequency front-end module described in any one of the above embodiments.

[0093] Reference Figure 7 As shown, the present application also provides a method for preparing a radio frequency front-end module, which is used to prepare the radio frequency front-end module described in any one of the above embodiments. The method includes:

[0094] S710. Provide a base substrate, fabricate a first epitaxial layer on a first surface of the base substrate, and fabricate a second epitaxial layer on a second surface of the base substrate; wherein, the material type of the first epitaxial layer is different from the material type of the base substrate, the material type of the second epitaxial layer is different from the material type of the base substrate, and the material type of the first epitaxial layer is different from the material type of the second epitaxial layer.

[0095] S720. Use a first photomask to etch a surface of the first epitaxial layer away from the base substrate to form a first device; wherein the device type of the first device matches the material type of the first epitaxial layer.

[0096] S730. Use a second photomask to etch a surface of the second epitaxial layer away from the base substrate to form a second device; wherein the device type of the second device matches the material type of the second epitaxial layer.

[0097] S740. Form a first protective layer around the first device and form a second protective layer around the second device; make a connection interface on the surface of the first protective layer or the second protective layer away from the base substrate to obtain a radio frequency front-end module.

[0098] Reference Figure 8a As shown, in the process of preparing the RF front-end module, a base substrate is first prepared. The material of the base substrate can be glass, quartz or ceramic, etc., which has a first surface and a second surface relative to each other.

[0099] Reference Figure 8b As shown, the first surface of the base substrate is placed vertically upward, and the material used for the first epitaxial layer is stacked on the first surface to form a first epitaxial layer on the first surface. Exemplarily, the material of the first epitaxial layer can be any one of the types such as single crystal silicon, piezoelectric material and gallium arsenide. In some embodiments, a first buffer layer may also be provided between the first epitaxial layer and the first surface to alleviate the material difference between the first epitaxial layer and the base substrate. It should be noted that placing the first surface of the base substrate vertically upward is only for the purpose of enabling the first epitaxial layer to be formed on the first surface, and is not used to limit the first surface to be vertically above the second surface.

[0100] Reference Figure 8c As shown, the second surface of the base substrate is placed vertically upward, and the material used for the second epitaxial layer is stacked on the second surface to form a second epitaxial layer on the second surface. Exemplarily, the material of the second epitaxial layer can be any of the types such as single crystal silicon, piezoelectric material and gallium arsenide. In some embodiments, a second buffer layer may be further provided between the second epitaxial layer and the second surface to alleviate the material difference between the second epitaxial layer and the base substrate. It should be noted that placing the second surface of the base substrate vertically upward is only for the purpose of enabling the second epitaxial layer to be formed on the second surface, and is not used to limit the second surface to be vertically above the first surface.

[0101] Furthermore, a corresponding first photomask is obtained based on the module design of the RF front-end module, and the first photomask is used to expose the surface of the first epitaxial layer away from the base substrate, thereby transferring the pre-designed device circuit pattern and the first signal trace pattern to the surface of the first epitaxial layer away from the base substrate, and then forming the first device and the first signal trace through processes such as etching. Similarly, a corresponding second photomask is obtained based on the module design of the RF front-end module, and the second photomask is used to expose the surface of the second epitaxial layer away from the base substrate, thereby transferring the pre-designed device circuit pattern and the second signal trace pattern to the surface of the second epitaxial layer away from the base substrate, and then forming the second device and the second signal trace through processes such as etching.

[0102] It should be noted that in this application, the surface of the epitaxial layer away from the base substrate is processed through the same mask to form corresponding devices and signal lines, so that only two different masks are required during the processing of the RF front-end module, which effectively reduces the number of masks required during the processing, simplifies the processing process and reduces the processing cost.

[0103] Furthermore, an insulating dielectric is deposited to form a first protective layer around the first device and a second protective layer around the second device, respectively, to provide physical protection and signal isolation for the first and second devices. A connection interface is formed on a surface of the first or second protective layer away from the base substrate, and the connection interface is electrically connected to the device in the adjacent protective layer, thereby obtaining an RF front-end module.

[0104] The RF front-end module obtained by this embodiment integrates a first epitaxial layer on the first surface of the base substrate, and integrates a second epitaxial layer of a different material on the opposite second surface, thereby realizing multi-material epitaxial layer integration on the base substrate; and the material types of the first epitaxial layer and the second epitaxial layer are matched with different device types, so that devices of different device types can be respectively set on the surfaces of the first epitaxial layer and the second epitaxial layer, thereby realizing multi-device integration suitable for different epitaxial layer materials in the RF front-end module, significantly improving the device integration level in the RF front-end module.

[0105] This application integrates multi-material epitaxial layers and multiple devices suitable for different epitaxial layer materials into the RF front-end module, so that the area of ​​the RF front-end module is reduced by half compared with the related technologies, and the number of devices that can be integrated in the same RF front-end module is significantly increased, effectively improving the degree of device integration in the RF front-end module, thereby being able to adapt to the needs of wireless communication technology for multi-functional communication.

[0106] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0107] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0108] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

[0109] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. A radio frequency front-end module, characterized in that: include: a base substrate having opposing first and second surfaces; a first epitaxial layer, the first epitaxial layer being disposed on the first surface, the material type of the first epitaxial layer matching the device type of the first device, so that the surface of the first epitaxial layer away from the base substrate is suitable for arranging the first device; a second epitaxial layer, the second epitaxial layer being disposed on the second surface, wherein a material type of the second epitaxial layer matches a device type of the second device, so that a surface of the second epitaxial layer away from the base substrate is suitable for disposing the second device; The material type of the first epitaxial layer is different from the material type of the base substrate, the material type of the second epitaxial layer is different from the material type of the base substrate, the material type of the first epitaxial layer is different from the material type of the second epitaxial layer, and the device type of the first device is different from the device type of the second device.

2. The RF front-end module according to claim 1, wherein: There are multiple first devices, the first devices are electrically connected to each other via a first signal line, and the first signal line is provided on a surface of the first epitaxial layer away from the base substrate; The plurality of first components and the first signal traces are all obtained by processing through the same photomask.

3. The RF front-end module according to claim 1, wherein: There are multiple second devices, the second devices are electrically connected to each other via a second signal line, and the second signal line is provided on a surface of the second epitaxial layer away from the base substrate; The plurality of second devices and the second signal traces are all obtained by processing through the same photomask.

4. The RF front-end module according to claim 1, wherein: Conductive vias are provided through the base substrate, the first epitaxial layer, and the second epitaxial layer, and the first device and the second device are electrically connected through the conductive vias.

5. The RF front-end module according to claim 1, wherein: A first protective layer wrapping the first device is provided on a surface of the first epitaxial layer away from the base substrate, and a second protective layer wrapping the second device is provided on a surface of the second epitaxial layer away from the base substrate; The RF front-end module further includes a connection interface, which is provided on a surface of the first protective layer or the second protective layer away from the base substrate.

6. The RF front-end module according to claim 1, wherein: A first buffer layer is provided between the first epitaxial layer and the base substrate, and a second buffer layer is provided between the second epitaxial layer and the base substrate.

7. The RF front-end module according to claim 1, wherein: The first epitaxial layer is a single crystal silicon thin film, and the device types of the first device include signal amplifiers, radio frequency switches and passive devices.

8. The RF front-end module according to claim 1, wherein: The second epitaxial layer is a piezoelectric film, and the device types of the second device include a duplexer and a filter.

9. A radio frequency terminal, characterized in that: The radio frequency terminal includes the radio frequency front-end module according to any one of claims 1 to 8.

10. A method for preparing a radio frequency front-end module, characterized in that: The method comprises: Providing a base substrate, forming a first epitaxial layer on a first surface of the base substrate, and forming a second epitaxial layer on a second surface of the base substrate; wherein the material type of the first epitaxial layer is different from the material type of the base substrate, the material type of the second epitaxial layer is different from the material type of the base substrate, and the material type of the first epitaxial layer is different from the material type of the second epitaxial layer; Using a first photomask, etching a surface of the first epitaxial layer away from the base substrate to form a first device; wherein the device type of the first device matches the material type of the first epitaxial layer; Using a second mask, etching a surface of the second epitaxial layer away from the base substrate to form a second device; wherein the device type of the second device matches the material type of the second epitaxial layer; A first protective layer is formed around the first device, and a second protective layer is formed around the second device; a connection interface is made on the surface of the first protective layer or the second protective layer away from the base substrate to obtain a radio frequency front-end module.

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