Integrated Chip, Its Manufacturing Method, and Integrated Circuit

Abstract

The application discloses an integrated chip, a manufacturing method thereof and an integrated circuit. The integrated chip includes a substrate, an epitaxial layer, an isolation structure, a gallium nitride high electron mobility transistor and a surface acoustic wave filter. The isolation structure divides the epitaxial layer into a first epitaxial layer and a piezoelectric layer, and isolates the gallium nitride high electron mobility transistor and the surface acoustic wave filter. The gallium nitride high electron mobility transistor includes a source electrode, a drain electrode and a gate electrode disposed on the first epitaxial layer. The surface acoustic wave filter includes a first interdigital transducer and a second interdigital transducer disposed on the piezoelectric layer. The gallium nitride high electron mobility transistor and the surface acoustic wave filter are interconnected through metal wires. Through the above design, the gallium nitride high electron mobility transistor and the surface acoustic wave filter in the radio frequency front end are integrated on one chip, thereby increasing the integration degree of radio frequency devices, achieving the purposes of reducing the device area, reducing losses and improving the overall performance of the device.

Description

Technical Field

[0001] This application relates to the field of wireless communication, and particularly to an integrated chip, a manufacturing method thereof, and an integrated circuit. Background Art

[0002] With the development of communication technology, radio frequency devices have been more and more widely used. In the radio frequency front end (RFFE), power amplifiers and filters are core components. Due to the good performance of bulk acoustic wave filters (SAW or BAW), they will be widely used in mobile communication systems; and high-performance gallium nitride high electron mobility transistor (GaN HEMT) devices will be adopted for power amplifiers.

[0003] Currently, filters based on SAW (surface acoustic wave resonator) and power amplifiers based on GaN HEMT (gallium nitride high electron mobility transistor) are fabricated separately, and then the separately fabricated filters and power amplifiers are integrated together during packaging, resulting in high device manufacturing cost, large chip area, and large system loss. Summary of the Invention

[0004] The purpose of this application is to provide an integrated chip, a manufacturing method thereof, and an integrated circuit that integrate gallium nitride high electron mobility transistors and surface acoustic wave filters on one chip, so as to reduce manufacturing cost, chip area, and system loss.

[0005] This application discloses an integrated chip, including a substrate, an epitaxial layer, an isolation structure, a gallium nitride high electron mobility transistor, and a surface acoustic wave filter. The epitaxial layer is disposed on the substrate and includes a channel layer and a barrier layer that are sequentially stacked on the substrate. The isolation structure penetrates the epitaxial layer and divides the epitaxial layer into a first epitaxial layer and a piezoelectric layer. The first epitaxial layer correspondingly forms a gallium nitride high electron mobility transistor, and the piezoelectric layer correspondingly forms a surface acoustic wave filter. The gallium nitride high electron mobility transistor includes a source electrode, a drain electrode, and a gate electrode disposed on the first epitaxial layer, and the source electrode, the drain electrode, and the gate electrode are arranged in parallel. The surface acoustic wave filter includes a first interdigital transducer and a second interdigital transducer disposed on the piezoelectric layer. The first interdigital transducer serves as the input transducer of the surface acoustic wave filter, and the second interdigital transducer serves as the output transducer of the surface acoustic wave filter. The gallium nitride high electron mobility transistor and the surface acoustic wave filter are interconnected through metal wires.

[0006] Optionally, the surface acoustic wave filter further includes a first reflector and a second reflector disposed on the piezoelectric layer. The first reflector is disposed between the isolation structure and the first interdigital transducer, and the second reflector is disposed on a side of the second interdigital transducer away from the first interdigital transducer. The first reflector and the second reflector are respectively composed of a plurality of juxtaposed metal strips.

[0007] Optionally, the epitaxial layer is an aluminum nitride material layer or an aluminum gallium nitride material layer, and the piezoelectric layer is an aluminum nitride material layer or an aluminum gallium nitride material layer doped with at least one rare metal particle.

[0008] Optionally, the thickness of the piezoelectric layer corresponding to the surface acoustic wave filter is greater than or equal to the thickness of the first epitaxial layer corresponding to the gallium nitride high electron mobility transistor.

[0009] Optionally, the epitaxial layer further includes one or more of a transition layer, a stress absorption layer, a nucleation layer, a buffer layer, and a superlattice layer.

[0010] Optionally, the integrated chip further includes a back hole and a back metal layer. The back hole penetrates through the substrate and the epitaxial layer, and the back metal layer is disposed on a side of the substrate away from the epitaxial layer and is connected to the source electrode through the back hole.

[0011] Optionally, the gallium nitride high electron mobility transistor serves as a power amplifier, a low noise amplifier, or a radio frequency switch in the integrated chip, and the surface acoustic wave filter serves as a radio frequency filter or a duplexer in the integrated chip.

[0012] The present application also discloses a method for manufacturing an integrated chip for manufacturing the integrated chip as described above, including the steps of:

[0013] Forming an epitaxial layer on a substrate;

[0014] Forming an isolation structure penetrating through the epitaxial layer. The isolation structure divides the epitaxial layer into a first epitaxial layer and a piezoelectric layer. The first epitaxial layer correspondingly forms a gallium nitride high electron mobility transistor, and the piezoelectric layer correspondingly forms a surface acoustic wave filter. The gallium nitride high electron mobility transistor and the surface acoustic wave filter are interconnected through metal wires.

[0015] Optionally, in the step of forming the epitaxial layer on the substrate, it includes:

[0016] Forming a channel layer made of gallium nitride material on the substrate; and

[0017] Forming a barrier layer made of aluminum nitride material on the channel layer;

[0018] Forming an isolation structure penetrating the epitaxial layer, the isolation structure dividing the epitaxial layer into a first epitaxial layer and a piezoelectric layer, where the first epitaxial layer correspondingly forms a gallium nitride high electron mobility transistor and the piezoelectric layer correspondingly forms a surface acoustic wave filter, includes:

[0019] Forming an isolation structure penetrating the epitaxial layer, the isolation structure dividing the epitaxial layer into a first epitaxial layer and a piezoelectric layer;

[0020] Synchronously forming a gate, a source, and a drain on the first epitaxial layer;

[0021] Synchronously forming a first interdigital transducer, a second interdigital transducer, a first reflector, and a second reflector on the piezoelectric layer;

[0022] Forming a passivation layer on the gate, the source, the drain, the first interdigital transducer, the second interdigital transducer, the first reflector, and the second reflector; and

[0023] Interconnecting the gallium nitride high electron mobility transistor and the first interdigital transducer of the surface acoustic wave filter through a metal.

[0024] This application also discloses an integrated circuit, including a wafer and the integrated chip as described above, where the integrated chip is disposed on the wafer.

[0025] Compared with the solution of separately manufacturing each part of the radio frequency front end, this application integrates the gallium nitride high electron mobility transistor and the surface acoustic wave filter in the radio frequency front end onto one chip, thereby reducing the area of the radio frequency device, improving the integration degree and overall performance of the device, and achieving the effects of reducing the manufacturing cost, chip area, and system loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings included are used to provide a further understanding of the embodiments of this application, which form a part of the specification, are used to illustrate the embodiments of this application, and together with the text description are used to explain the principles of this application. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings:

[0027] Figure 1 is a schematic diagram of an integrated circuit provided by an embodiment of this application;

[0028] Figure 2 is a schematic diagram of an integrated chip provided by an embodiment of this application;

[0029] Figure 3 is a schematic diagram of a wireless communication system;

[0030] Figure 4 is Figure 3 a schematic diagram of a radio frequency front end;

[0031] Figure 5 is a schematic diagram of a transmitting channel of a radio frequency front end provided by an embodiment of the present application;

[0032] Figure 6 is a schematic diagram of a receiving channel of a radio frequency front end provided by an embodiment of the present application;

[0033] Figure 7 is a schematic diagram of a transceiver channel of a radio frequency front end provided by an embodiment of the present application;

[0034] Figure 8 is a schematic diagram of a transmitting channel of a radio frequency front end of a multi-channel system provided by an embodiment of the present application;

[0035] Figure 9 is a schematic diagram of a receiving channel of a radio frequency front end of a multi-channel system provided by an embodiment of the present application;

[0036] Figure 10 is a schematic diagram of another transmitting channel of a radio frequency front end of a multi-channel system provided by an embodiment of the present application;

[0037] Figure 11 is a schematic diagram of another receiving channel of a radio frequency front end of a multi-channel system provided by an embodiment of the present application;

[0038] Figure 12 is a schematic diagram of a single-channel transceiver system provided by an embodiment of the present application;

[0039] Figure 13 is a schematic diagram of an integrated chip with an intermediate layer provided by an embodiment of the present application;

[0040] Figure 14 is a schematic diagram of an epitaxial layer provided by an embodiment of the present application;

[0041] Figure 15 is a cross-sectional schematic diagram of another integrated chip provided by an embodiment of the present application;

[0042] Figure 16 is a planar schematic diagram of a surface acoustic wave filter provided by an embodiment of the present application;

[0043] Figure 17 is a schematic diagram of an integrated chip combined with a back hole process provided by an embodiment of the present application;

[0044] Figure 18 is a flowchart of a method for manufacturing an integrated chip provided by an embodiment of the present application;

[0045] Figure 19 It is a flowchart of another integrated chip manufacturing method provided by an embodiment of the present application.

[0046] Among them, 100 is a wireless communication system; 110 is a radio frequency front end; 111 is a power amplifier; 113 is a duplexer; 114 is a low-noise amplifier; 115 is a radio frequency switch; 120 is a baseband chip; 130 is a transceiver; 140 is an antenna; 200 is an integrated circuit; 210 is a wafer; 220 is an integrated chip; 221 is a substrate; 222 is a channel layer; 223 is an epitaxial layer; 2231 is a barrier layer; 2232 is a piezoelectric layer; 224 is an isolation structure; 225 is a gallium nitride high electron mobility transistor; 2251 is a source electrode; 2252 is a gate electrode; 2253 is a drain electrode; 226 is a surface acoustic wave filter; 2261 is a first interdigital transducer; 2262 is a second interdigital transducer; 2263 is a first reflector; 2264 is a second reflector; 227 is an intermediate layer; 228 is a back hole; 2281 is a back metal layer; 229 is a passivation layer; 2291 is a first via hole; 2292 is a second via hole; 2293 is a third via hole; 230 is a metal wire; 240 is a first epitaxial layer. Detailed implementation manners

[0047] It should be understood that the terms, specific structures and functional details disclosed here are only for describing specific embodiments and are representative, but the present application can be specifically implemented in many alternative forms and should not be construed as being limited only to the embodiments set forth herein.

[0048] The present application will be described in detail below with reference to the accompanying drawings and optional embodiments.

[0049] As Figure 1 shown, it is a schematic diagram of an integrated circuit provided by an embodiment of the present application. The integrated circuit 200 includes a wafer 210 and an integrated chip 220. The integrated chip 220 is disposed on the wafer 210. Each small square on the wafer 210 in the figure is an integrated chip 220, and an integrated solution for manufacturing various radio communication radio frequency front ends 110, such as a power amplifier 111, a surface acoustic wave filter 226, a low-noise amplifier 114, a radio frequency switch 115, etc. is made thereon; wherein the initial thickness of the wafer 210 is 0.3 - 1 mm, and the general thickness after manufacturing is between 25 - 150 um.

[0050] As Figure 2As shown, the integrated chip 220 in the integrated circuit 200 includes a substrate 221, an epitaxial layer 223, an isolation structure 224, a gallium nitride high electron mobility transistor 225, and a surface acoustic wave filter 226. The epitaxial layer 223 is disposed on the substrate 221 and includes a channel layer 222 and a barrier layer 2231 that are sequentially stacked on the substrate 221. The isolation structure 224 penetrates through the epitaxial layer 223 and divides the epitaxial layer 223 into a first epitaxial layer 240 and a piezoelectric layer 2232. The first epitaxial layer 240 correspondingly forms the gallium nitride high electron mobility transistor 225, and the piezoelectric layer 2232 correspondingly forms the surface acoustic wave filter 226. The gallium nitride high electron mobility transistor 225 includes a source electrode 2251, a drain electrode 2253, and a gate electrode 2252 disposed on the first epitaxial layer 240, and the source electrode 2251, the drain electrode 2253, and the gate electrode 2252 are arranged in parallel. The surface acoustic wave filter 226 includes a first interdigital transducer 2261 and a second interdigital transducer 2262 disposed on the piezoelectric layer 2232. The first interdigital transducer 2261 serves as the input transducer of the surface acoustic wave filter 226, and the second interdigital transducer 2262 serves as the output transducer of the surface acoustic wave filter 226. The gallium nitride high electron mobility transistor 225 and the surface acoustic wave filter 226 are interconnected by a metal wire 230.

[0051] The integrated chip 220 in this application is used for radio frequency devices, especially radio frequency front-ends. In a wireless communication system, the radio frequency front-end is a very important part and is the core part for receiving and transmitting radio frequency signals at the very front end of the entire wireless communication intelligent terminal, directly affecting the signal reception and transmission of mobile phones. Compared with the solution of separately manufacturing each part of the radio frequency front-end, in this application, the gallium nitride high electron mobility transistor and the surface acoustic wave filter in the radio frequency front-end are integrated on one chip, thereby reducing the volume of the radio frequency device, improving the overall performance of the device, and achieving the effects of reducing manufacturing costs, chip area, and system losses.

[0052] As Figure 3As shown in the figure, it is a schematic diagram of a wireless communication system. The wireless communication system 100 includes a baseband chip 120, a transceiver 130, a radio frequency front-end 110, and an antenna 140. The radio frequency front-end 110 is connected to the antenna 140 and is used to receive and transmit radio frequency signals. The radio frequency front-end 110 conducts the received signal (Rx) to the radio frequency transceiver 130 and simultaneously receives the transmitted signal (Tx) from the transceiver 130. The baseband chip 120 is responsible for demodulating, descrambling, despreading, and decoding wireless signals in the mobile network. During the process of transmitting signals, the radio frequency front-end 110 receives the binary signal from the transceiver 130 and converts it into a high-frequency radio electromagnetic wave signal to be sent to the antenna 140. During the process of receiving signals, the electromagnetic wave signal received from the antenna 140 is converted into a binary digital signal and sent to the transceiver 130.

[0053] In 5G and future communications, radio frequency devices will be more and more widely used, such as Figure 4 As shown in the figure, it is a schematic diagram of the radio frequency front-end in a wireless communication system. The radio frequency front-end 110 in this application includes devices such as a power amplifier 111 (PA), a surface acoustic wave filter 226 (SAW), a duplexer 113, a low-noise amplifier 114 (LNA), and a radio frequency switch 115 (Switch). Among them, the power amplifier 111, the low-noise amplifier 114, and / or the radio frequency switch 115 are composed of gallium nitride high electron mobility transistors 225. The power amplifier 111 (PA) is used to amplify the radio frequency signal in the transmission channel. The radio frequency switch 115 (Switch) is used to switch between receiving and transmitting radio frequency signals. The surface acoustic wave filter 226 is used to retain signals within a specific frequency band and filter out signals outside the specific frequency band. The duplexer 113 (Duplexer) is composed of a receiving surface acoustic wave filter and a transmitting surface acoustic wave filter, and is used to isolate the transmitted and received signals to ensure normal operation when receiving and transmitting share the same antenna 140. The low-noise amplifier 114 (LNA) is used to amplify the radio frequency signal in the receiving channel.

[0054] In the present application, the gallium nitride high electron mobility transistor 225 can serve as a power amplifier, a low-noise amplifier, or a radio frequency switch in the integrated chip 220, and the surface acoustic wave filter 226 can serve as a radio frequency filter or a duplexer in the integrated chip. The integrated gallium nitride high electron mobility transistor (GaN HEMT) 225 and the surface acoustic wave filter (SAW) 226 can be used in various radio frequency scenarios. When the gallium nitride high electron mobility transistor 225 serves as a power amplifier and the surface acoustic wave filter 226 serves as a filter, one gallium nitride high electron mobility transistor 225 and one surface acoustic wave filter 226 are combined to form the transmission channel of the radio frequency front end 110; when the gallium nitride high electron mobility transistor 225 serves as a low-noise amplifier and the surface acoustic wave filter 226 serves as a filter, one gallium nitride high electron mobility transistor 225 and one surface acoustic wave filter 226 are combined to form the receiving channel of the radio frequency front end 110; additionally, by adjusting the spacing of the interdigital transducers, the surface acoustic wave filter 226 can act as a duplexer to isolate the transmitted and received signals. At this time, one gallium nitride high electron mobility transistor 225 serves as a power amplifier and one gallium nitride high electron mobility transistor 225 serves as a low-noise amplifier, respectively combined with the duplexer, providing another new solution for the radio frequency front end of the wireless communication system.

[0055] Specifically, the transmission channel of the radio frequency front end 110 is as Figure 5 shown, and the receiving channel of the radio frequency front end 110 is as Figure 6 shown. The duplexer 113 of the radio frequency front end 110, that is, the transceiver channel, is as Figure 7 shown. For a multi-channel system, different solutions can be adopted. For example, a solution of one power amplifier 111 plus multiple radio frequency switches 115 and multiple surface acoustic wave filters 226 can be adopted. Its transmission channel is as Figure 8 shown, and its receiving channel is as Figure 9 shown; as shown in the figure, there are 8 channels, with a total of 8 surface acoustic wave filters 226 and 16 radio frequency switches 115; the 8 surface acoustic wave filters 226 are filters with different frequencies, and the 16 radio frequency switches 115 are 16 GaN HEMT transistors. All the components are integrated on the same chip to achieve the purpose of reducing the device size, lowering the cost, and improving the performance. Of course, the multi-channel system can also adopt a solution of multiple power amplifiers 111 plus multiple radio frequency switches 115 and multiple surface acoustic wave filters 226; as Figure 10 shown, it is a schematic diagram of the transmission channel of this solution. The power amplifier 111 is a GaN HEMT transistor, corresponding one by one to the surface acoustic wave filter 226; the receiving channel of this solution is as Figure 11As shown, an equal number of low-noise amplifiers (LNAs) based on GaN HEMT and RF switches 115 based on GaN HEMT are adopted. All components are integrated on the same chip to achieve the purpose of reducing device size, lowering cost, and improving performance.

[0056] Furthermore, all devices of the RF front-end 110 can be integrated on the same chip, as Figure 12 shown, which is the simplest single-channel transceiver system. Based on the present patented technology, since the power amplifier, low-noise amplifier, transceiver filter, and RF switch are all integrated on the same chip, only one chip is needed, greatly reducing the device size, lowering the cost, and improving the performance.

[0057] For a multi-channel system, in the existing solutions, multiple PAs and LNAs are required, and the number of receive filters and transmit filters equal to the number of channels is needed. Therefore, the number of required chips will increase significantly as the number of channels increases, and the total number of chips reaches dozens or even hundreds. While the present application can select any of the above solutions or a combination of different solutions, only the corresponding number of power amplifiers, low-noise amplifiers, receive filters, transmit filters, and RF switches need to be added on the integrated chip, without increasing the number of chips. In this way, regardless of which solution, the number of chips will be greatly reduced. Among them, the power amplifier 111 (PA), low-noise amplifier 114 (LNA), and RF switch 115 are all made based on gallium nitride high electron mobility transistors 221, and the receive (Rx) and transmit (Tx) filters 112 are surface acoustic wave filters 226 with different designs. The patented product of the present invention will be widely applied in 5G and future communications or other terminal devices.

[0058] In the integrated chip 220, the substrate 221 is made of silicon, silicon oxide, silicon carbide, sapphire, or other materials, and the size of the substrate 221 is between 3 - 12 inches; among them, the substrate 221 can be formed by SOI (Silicon-On-Insulator) silicon technology. As Figure 13 shown, the channel layer 222 is made of gallium nitride material, and an intermediate layer 227 is further provided between the channel layer 222 and the substrate 221. The average lattice constant of the intermediate layer 227 is between the lattice constant of the substrate 221 material and the lattice constant of the channel layer 222 material. The intermediate layer 227 can be a nucleation layer, buffer layer, transition layer, or superlattice layer, etc. The epitaxial layer 223 includes one or more of a transition layer, stress absorption layer, nucleation layer, buffer layer, and superlattice layer. By adding the intermediate layer 227, the purpose of absorbing stress and reducing dislocations can be achieved, preventing dislocations, warping, and cracking caused by lattice mismatch and different thermal expansion coefficients between the substrate 221 and the channel layer 222.

[0059] In addition, the barrier layer 2231 is disposed on the channel layer 222, and it can be aluminum nitride (AlN), aluminum gallium nitride (AlGaN), or other materials. The material and thickness of the barrier layer 2231 are determined by the design of the GaN HEMT transistor. When the barrier layer 2231 is made of aluminum nitride material, the thickness of the barrier layer 2231 is 2 - 20 nm; when the barrier layer 2231 is made of aluminum gallium nitride, the thickness of the barrier layer 2231 is 15 - 50 nm. The piezoelectric layer 2232 is disposed in parallel with the barrier layer 2231 on the channel layer 222, and it can be aluminum nitride, gallium nitride, or aluminum gallium nitride, or other materials.

[0060] The isolation structure 224 located between the first epitaxial layer 240 and the piezoelectric layer 2232 can be an isolation groove. After the epitaxial layer 223 is fabricated, the epitaxial layer 223 is etched to form an isolation groove penetrating the epitaxial layer 223, dividing the epitaxial layer 223 into the first epitaxial layer 240 and the piezoelectric layer 2232. Thus, in subsequent processes, the gallium nitride high electron mobility transistor 225 is fabricated on the first epitaxial layer 240, and the surface acoustic wave filter 226 is fabricated on the piezoelectric layer 2232, and interference between the gallium nitride high electron mobility transistor 225 and the surface acoustic wave filter 226 is avoided.

[0061] Furthermore, at least one rare metal particle can be doped into the piezoelectric layer 2232. Commonly used doping metals include scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), erbium (Er), and chromium (Cr). Taking Sc as an example, when the piezoelectric layer 2232 is made of aluminum nitride material, after doping, Sc atoms replace some Al atoms to form scandium nitride (ScN). Scandium nitride is a non-polar III-V nitride with a rock salt structure, while aluminum nitride is a polar III-V nitride with a wurtzite structure. When Sc doping is achieved for AlN, a transition region between the wurtzite structure and the rock salt structure is formed, thereby improving the piezoelectric coefficient of the aluminum nitride thin film. Appropriate Sc doping can increase the piezoelectric coefficient of the AlN thin film by 100 - 500%, greatly improving the performance of the surface acoustic wave filter 226.

[0062] Moreover, as Figure 14As shown, the height of the piezoelectric layer 2232 can also be increased such that the thickness of the piezoelectric layer 2232 is greater than the thickness of the first epitaxial layer 240. When the thickness of the piezoelectric layer 2232 increases, the electromechanical coupling coefficient of the piezoelectric layer 2232 is further improved. In terms of the manufacturing process, a relatively thick epitaxial layer 223 can be fabricated, and then the corresponding part of the barrier layer 2231 can be thinned; alternatively, after the epitaxial layer 223 is fabricated, a film layer of the same material can be further added to the corresponding part of the piezoelectric layer 2232. Of course, the thickness of the first epitaxial layer 240 can also be equal to the thickness of the piezoelectric layer 2232.

[0063] In the gallium nitride high electron mobility transistor 225, it includes a source electrode 2251, a drain electrode 2253, and a gate electrode 2252 located above the barrier layer 2231. The source electrode 2251 and the drain electrode 2253 can be directly fabricated on the surface of the barrier layer 2231, and can be composed of materials such as Ti, Al, Ni, or Au, and are deposited layer by layer onto the piezoelectric layer 2232 through metal sputtering or metal evaporation; or they can be composed of an alloy formed by annealing a combination of several metals, which can further reduce the resistance. After the source electrode 2251 and the drain electrode 2253 are fabricated, a passivation layer 229 is formed on the source electrode 2251 and the drain electrode 2253. Subsequently, the passivation layer 229 is etched to form a first via 2291, and then the gate electrode 2252 is fabricated into the first via 2291; the gate electrode 2252 can be composed of metals such as Ni, Au, Pt, Ti, or Al, and the cross-sectional shape of the gate electrode 2252 can be rectangular, or can be in the shape of "T" or "Y", etc., which is not limited herein; moreover, an insulating layer can be added between the gate electrode 2252 and the barrier layer 2231, and the insulating layer can adopt materials such as aluminum oxide (Al2O3) or silicon nitride (Si3N).

[0064] In the surface acoustic wave filter 226, it includes a dual-port resonator disposed on the piezoelectric layer 2232. The dual-port resonator includes a first interdigital transducer 2261 and a second interdigital transducer 2262. The first interdigital transducer 2261 and the second interdigital transducer 2262 are arranged in parallel. The first interdigital transducer 2261 is connected to the drain electrode 2253 in the gallium nitride high electron mobility transistor 225 to input a filter signal, and the second interdigital transducer 2262 is connected to other devices in the integrated chip 220 to output a filter signal. Moreover, as Figure 15 and Figure 16As shown, the surface acoustic wave filter 226 in the present application further includes a first reflector 2263 and a second reflector 2264 disposed on the piezoelectric layer 2232. The first reflector 2263 is disposed between the isolation structure 224 and the first interdigital transducer 2261, and the second reflector 2264 is disposed on the side of the second interdigital transducer 2262 away from the first interdigital transducer 2261. Of course, the dual-port resonator can also be replaced with a single-port resonator, and the interdigital transducer can be correspondingly modified.

[0065] Since the function of the piezoelectric layer 2232 is to realize the mutual conversion between mechanical energy and electrical energy, after the first interdigital transducer 2261 receives an electrical signal, through the piezoelectric effect, the electrical signal is converted into an acoustic wave signal, and the acoustic wave signal propagates along the surface of the piezoelectric layer 2232, and then the acoustic wave signal is converted into an electrical signal and output through the second interdigital transducer 2262. In the present application, corresponding first reflector 2263 and second reflector 2264 are respectively added outside the first interdigital transducer 2261 and the second interdigital transducer 2262, and the reflectors are made of a metal material or other materials that can reflect acoustic waves.

[0066] And the first reflector 2263 and the second reflector 2264 are respectively composed of a plurality of metal strips arranged in parallel. The properties of the surface acoustic wave filter 226 can be adjusted by adjusting the number of metal strips and the spacing between adjacent metal strips in the first reflector 2263 and the second reflector 2264.

[0067] The first reflector 2263, the second reflector 2264, the first interdigital transducer 2261 and the second interdigital transducer 2262 are all made of a metal material, which can be Au, Al, Ti, Mo, Cr, Cu, W, etc., and are fabricated by methods such as metal sputtering and evaporation. Moreover, the first reflector 2263, the second reflector 2264, the first interdigital transducer 2261 and the second interdigital transducer 2262 can be formed by the same process, and further can be formed by the same process with the source electrode 2251 and the drain electrode 2253 in the gallium nitride high electron mobility transistor 225, so as to shorten the manufacturing time of the integrated chip 220.

[0068] While forming the first via 2291 in the etch stop layer 229, the etch stop layer 229 can be etched synchronously to form a second via 2292 and a third via 2293. The second via 2292 is located above the drain 2253, and the third via 2293 is located above the first interdigital transducer 2261. Then, while depositing a metal material in the first via 2291 to form the gate 2252, a metal material can be deposited synchronously in the second via 2292 and the third via 2293, as well as on the etch stop layer 229, to form a metal bridge 230 connecting the drain 2253 and the first interdigital transducer 2261. Through the above design, the manufacturing efficiency of the integrated chip 220 can be further improved, and the production cost can be reduced.

[0069] In addition, as Figure 17 shown, the integrated chip 220 further includes a back hole 228 and a back metal layer 2281. The back hole 228 penetrates through the substrate 221 and the epitaxial layer 223. The back metal layer 2281 is disposed on a surface of the substrate 221 away from the epitaxial layer 223 and is connected to the source 2251 through the back hole 228. In this way, the source 2251 of the transistor can be grounded through the back metal layer 2281, thereby further reducing the inductance of the source 2251 and increasing the device performance.

[0070] As Figure 18 shown, the present application also discloses a manufacturing method of the above integrated chip, including the steps of:

[0071] S1: Form an epitaxial layer on a substrate;

[0072] S2: Form an isolation structure penetrating through the epitaxial layer. The isolation structure divides the epitaxial layer into a first epitaxial layer and a piezoelectric layer. The first epitaxial layer correspondingly forms a gallium nitride high electron mobility transistor, and the piezoelectric layer correspondingly forms a surface acoustic wave filter. The gallium nitride high electron mobility transistor and the surface acoustic wave filter are interconnected through a metal wire.

[0073] Specifically, as Figure 19 shown, in step S1, it includes:

[0074] S11: Form a channel layer made of gallium nitride material on a substrate;

[0075] S12: Form a barrier layer made of aluminum nitride material on the channel layer.

[0076] In step S2, it includes:

[0077] S21: Form an isolation structure penetrating through the epitaxial layer. The isolation structure divides the epitaxial layer into a first epitaxial layer and a piezoelectric layer;

[0078] S22: Synchronously form a gate, a source, and a drain on the first epitaxial layer;

[0079] S23: Synchronously form a first interdigital transducer, a second interdigital transducer, a first reflector, and a second reflector on the piezoelectric layer;

[0080] S24: Form a passivation layer on the gate, the source, the drain, the first interdigital transducer, the second interdigital transducer, the first reflector, and the second reflector;

[0081] S25: Interconnect the gallium nitride high electron mobility transistor and the first interdigital transducer of the surface acoustic wave filter through metal.

[0082] In step S21, the width of the isolation structure is between 1 - 20 um; moreover, S22 can be completed first and then S23, or S23 can be completed first and then S22, or S22 and S23 can be completed synchronously. Of course, the manufacturing process of the gallium nitride high electron mobility transistor can also be completed first and then the manufacturing process of the surface acoustic wave filter can be started; or the manufacturing process of the surface acoustic wave filter can be completed first and then the manufacturing process of the gallium nitride high electron mobility transistor can be started.

[0083] The above steps are the front - end processes of the integrated chip. After completing step S2, the substrate is bonded, thinned, and polished, and then the back - hole process of the gallium nitride high electron mobility transistor is started, including the steps of etching vias on the back of the substrate corresponding to the gallium nitride high electron mobility transistor and depositing a back - side metal layer.

[0084] It should be noted that the limitations of each step involved in this solution do not, on the premise of not affecting the implementation of the specific solution, be regarded as limiting the sequence of the steps. The steps written in the front can be executed first, or later, or even simultaneously. As long as the solution can be implemented, it should be regarded as falling within the protection scope of this application.

[0085] The above content is a further detailed description of this application in combination with specific optional implementation manners. It cannot be determined that the specific implementation of this application is only limited to these descriptions. For those of ordinary skill in the technical field to which this application belongs, without departing from the concept of this application, several simple deductions or substitutions can still be made, and all should be regarded as falling within the protection scope of this application.

Claims

1. An integrated chip, characterized in that, Comprising: A substrate; An epitaxial layer, including a channel layer and a barrier layer stacked in sequence on the substrate; An isolation structure, penetrating through the epitaxial layer, dividing the epitaxial layer into a first epitaxial layer and a piezoelectric layer, the first epitaxial layer corresponding to form a gallium nitride high electron mobility transistor, and the piezoelectric layer corresponding to form a surface acoustic wave filter; The gallium nitride high electron mobility transistor includes a source electrode, a drain electrode, and a gate electrode disposed on the first epitaxial layer, and the source electrode, the drain electrode, and the gate electrode are arranged in parallel; The surface acoustic wave filter includes a first interdigital transducer and a second interdigital transducer disposed on the piezoelectric layer, the first interdigital transducer serving as the input transducer of the surface acoustic wave filter; the second interdigital transducer serving as the output transducer of the surface acoustic wave filter; The gallium nitride high electron mobility transistor and the surface acoustic wave filter are interconnected by metal wires; The epitaxial layer is an aluminum nitride material layer or an aluminum gallium nitride material layer, and the piezoelectric layer is an aluminum nitride material layer doped with a rare metal particle of scandium; after doping the aluminum nitride material layer with scandium metal particles, a transition region between the wurtzite structure and the rock salt structure is formed in the piezoelectric layer; wherein, the scandium metal particles replace some aluminum atoms in the aluminum nitride material layer to form scandium nitride, and scandium nitride is a non-polar III-V nitride with a rock salt structure, and aluminum nitride is a polar III-V nitride with a wurtzite structure; The thickness of the piezoelectric layer corresponding to the surface acoustic wave filter is greater than the thickness of the first epitaxial layer corresponding to the gallium nitride high electron mobility transistor.

2. The integrated chip according to claim 1, characterized in that, The surface acoustic wave filter further includes a first reflector and a second reflector disposed on the piezoelectric layer, the first reflector is disposed between the isolation structure and the first interdigital transducer, and the second reflector is disposed on the side of the second interdigital transducer away from the first interdigital transducer; The first reflector and the second reflector are respectively composed of a plurality of metal strips arranged in parallel.

3. The integrated chip according to claim 1, wherein The epitaxial layer further includes one or more of a transition layer, a stress absorption layer, a nucleation layer, a buffer layer, and a superlattice layer.

4. The integrated chip according to claim 3, wherein The integrated chip further includes a back hole and a back metal layer, the back hole penetrates through the substrate and the epitaxial layer, and the back metal layer is disposed on the side of the substrate away from the epitaxial layer and is connected to the source electrode through the back hole.

5. The integrated chip according to any one of claims 1-4, characterized in that, The gallium nitride high electron mobility transistor serves as a power amplifier, a low noise amplifier, or a radio frequency switch in the integrated chip, and the surface acoustic wave filter serves as a radio frequency filter or a duplexer in the integrated chip.

6. A method for manufacturing an integrated chip, which is used to manufacture the integrated chip as described in any one of claims 1-5, characterized in that, Including steps: Forming an epitaxial layer on a substrate; Forming an isolation structure penetrating through the epitaxial layer, the isolation structure dividing the epitaxial layer into a first epitaxial layer and a piezoelectric layer, the first epitaxial layer corresponding to form a gallium nitride high electron mobility transistor, the piezoelectric layer corresponding to form a surface acoustic wave filter, and the gallium nitride high electron mobility transistor and the surface acoustic wave filter are interconnected by metal wires.

7. The manufacturing method of the integrated chip according to claim 6, characterized in that, In the step of forming the epitaxial layer on the substrate, it includes: Forming a channel layer made of gallium nitride material on the substrate; and Forming a barrier layer made of aluminum nitride material on the channel layer; The step of forming an isolation structure penetrating the epitaxial layer, the isolation structure dividing the epitaxial layer into a first epitaxial layer and a piezoelectric layer, the first epitaxial layer correspondingly forming a gallium nitride high electron mobility transistor, and the piezoelectric layer correspondingly forming a surface acoustic wave filter includes: Forming an isolation structure penetrating the epitaxial layer, the isolation structure dividing the epitaxial layer into a first epitaxial layer and a piezoelectric layer; Synchronously forming a gate, a source, and a drain on the first epitaxial layer; Synchronously forming a first interdigital transducer, a second interdigital transducer, a first reflector, and a second reflector on the piezoelectric layer; Forming a passivation layer on the gate, the source, the drain, the first interdigital transducer, the second interdigital transducer, the first reflector, and the second reflector; and Interconnecting the gallium nitride high electron mobility transistor and the first interdigital transducer of the surface acoustic wave filter through a metal.

8. An integrated circuit, characterized in that, Including a wafer and an integrated chip as described in any one of claims 1-5, the integrated chip being disposed on the wafer.

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