Radio frequency front-end structure integrated with pa, and preparation method therefor

Abstract

Disclosed in the present application are a radio frequency front-end structure integrated with a PA, and a preparation method therefor. The radio frequency front-end structure integrated with a PA comprises: a substrate; a BAW filter structure, which is arranged on the substrate; an IPD MIM capacitor structure, which is arranged on the BAW filter structure; a GaN HENT transistor structure, which is arranged on the IPD MIM capacitor structure; and an IPD TGV inductor structure, which is arranged on the GaN HENT transistor structure. By means of the present application, a PA is integrated into a radio frequency front-end structure, so as to reduce space occupation, and also reduce the production costs. The present application relates to the fields of semiconductor technology and radio frequency front-end devices.

Description

Integrated PA radio frequency front-end structure and preparation method thereof TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor technology and radio frequency front-end devices, in particular to an integrated PA radio frequency front-end structure and a preparation method thereof. BACKGROUND

[0002] Body acoustic wave resonator (BAW) has the advantages of high frequency, miniaturization, high performance, low power consumption, high power capacity, etc., and the manufacturing process of BAW filter is compatible with IC process, which can be integrated, thereby being conducive to reducing device power consumption and reducing device size. BAW filter is the only integrated radio frequency front-end filter at present. Therefore, BAW filter will become a core component of 5G high-frequency communication. The working frequency range of BAW filter using micro-machining technology (MEMS) can be from several hundred MHz to several tens of GHz, which completely covers the requirements of wireless communication frequency band. The traditional dielectric filter is too large in size, the insertion loss of SAW filter is larger than that of BAW filter, and it cannot meet the demand of high frequency (>3GHz), so BAW filter is the optimal solution for high frequency band above 3GHz.

[0003] Radio frequency power amplifiers composed of gallium nitride (GaN) based high electron mobility transistors (HEMTs) exhibit unique advantages in the field of radio frequency. First, GaN HEMTs exhibit excellent power density, enabling high power output in relatively small device sizes, making them suitable for applications requiring high power density, such as communication and radar systems. Second, GaN HEMTs have outstanding high-frequency performance, with high cutoff frequencies and wideband characteristics, making them superior in high-frequency ranges, suitable for high-speed data transmission and wideband communication. In addition, GaN HEMTs have high operating temperature adaptability, maintaining stability in relatively high temperature environments, meeting the needs of high temperature applications. Most importantly, their excellent linearity and fast switching characteristics make them an ideal choice for high-efficiency and high-performance radio frequency systems. GaN HEMTs have significant advantages over other radio frequency power amplifier technologies in terms of power density, high-frequency performance, operating temperature adaptability, linearity, and switching characteristics, providing advanced solutions for radio frequency applications.

[0004] Under the background of pursuing the miniaturization and high performance of electronic devices, the monolithic integration of bulk acoustic wave filters and power amplifiers (PAs) based on high electron mobility transistors (HEMTs) has become one of the focuses of key technologies in radio frequency front-end modules. The integration of bulk acoustic wave filters and HEMT power amplifiers can simplify the system design and layout of radio frequency front-end modules, and also reduce manufacturing costs. This is particularly important for mass production. Reducing costs not only makes the integration technology more attractive, but also makes the product more competitive in the market.

[0005] SUMMARY

[0006] The present application aims to at least solve one of the problems in the prior art, and provide a radio frequency front end structure integrated with a PA and a preparation method thereof, which can occupy less space and reduce manufacturing cost.

[0007] According to the first aspect of the present application, a radio frequency front end structure integrated with a PA is provided, comprising:

[0008] a substrate;

[0009] a BAW filter structure disposed on the substrate;

[0010] an IPD MIM capacitor structure disposed on the BAW filter structure;

[0011] a GaN HENT transistor structure disposed on the IPD MIM capacitor structure;

[0012] an IPD TGV inductor structure disposed on the GaN HENT transistor structure.

[0013] According to the first aspect of the present application, further, the BAW filter structure comprises, from bottom to top, a sound wave reflection layer, a filter bottom electrode, a filter piezoelectric layer and a filter top electrode.

[0014] According to the first aspect of the present application, further, the IPD MIM capacitor structure comprises, from bottom to top, a first capacitor metal layer, a capacitor insulating layer and a second capacitor metal layer.

[0015] According to the first aspect of the present application, further, an electromagnetic shielding layer is disposed between the BAW filter structure and the IPD MIM capacitor structure.

[0016] According to the first aspect of the present application, further, the GaN HENT transistor structure comprises, from bottom to top, a buffer layer, a channel layer, a barrier layer and a field effect transistor, the field effect transistor comprising a source, a gate and a drain.

[0017] According to the first aspect of the present application, further, the GaN HENT transistor structure further comprises a mesa isolation layer, the mesa isolation layer being disposed outside the channel layer, the barrier layer and the field effect transistor.

[0018] According to the first aspect of the present application, further, the IPD TGV inductance structure comprises inductance metal layers and inductance insulating layers stacked in turn from bottom to top.

[0019] According to the first aspect of the present application, further, the IPD TGV inductance structure and the GaN HENT transistor structure are connected together through a solder joint.

[0020] According to the second aspect of the present application, a preparation method of the radio frequency front end structure of the integrated PA is provided, comprising the following steps:

[0021] The substrate is cleaned;

[0022] A sound wave reflection layer is obtained by spin coating and curing on the surface of the substrate;

[0023] A filter bottom electrode is prepared on the surface of the cured sound wave reflection layer;

[0024] A filter piezoelectric layer is prepared on the basis of the filter bottom electrode by magnetron sputtering;

[0025] The filter piezoelectric layer is etched, and a filter top electrode is prepared thereon, and the BAW filter structure is prepared;

[0026] An electromagnetic shielding layer is laid on the surface of the filter top electrode;

[0027] A first capacitor metal layer is prepared on the surface of the electromagnetic shielding layer;

[0028] A capacitor insulating layer is prepared on the surface of the first capacitor metal layer;

[0029] A second capacitor metal layer is prepared on the surface of the capacitor insulating layer, and the IPD MIM capacitor structure is prepared;

[0030] A buffer layer is prepared on the second capacitor metal layer by metal organic chemical vapor deposition epitaxial growth;

[0031] A channel layer is prepared on the buffer layer by metal organic chemical vapor deposition epitaxial growth;

[0032] A barrier layer is prepared on the channel layer by metal organic chemical vapor deposition epitaxial growth;

[0033] A field effect transistor is prepared on the barrier layer;

[0034] A cavity is etched on the side of the field effect transistor, and a passivation material is filled in the cavity to obtain a mesa isolation layer, and the GaN HENT transistor structure is prepared;

[0035] Prepare another substrate, spin-coat solidification to obtain an inductor metal layer on the substrate;

[0036] Deposition of SiO2 on the surface of the inductor metal layer by low-temperature CVD;

[0037] Prepare an inductor insulating layer on the SiO2 film, and the IPD TGV inductor structure is prepared;

[0038] Turn over the IPD TGV inductor structure, and combine the IPD TGV inductor structure with the GaN HENT transistor structure through the solder joints to obtain the integrated PA radio frequency front-end structure.

[0039] According to the second aspect of the present application, further, after the filter top electrode is prepared, deep hole etching is performed on the filter top electrode, which penetrates the filter piezoelectric layer to the filter bottom electrode, and a layer of Mo metal is deposited on the surface of the deep hole by physical vapor deposition, connecting the top and bottom electrodes of the two resonators, so that the two resonators are connected in series.

[0040] The beneficial effects of the embodiments of the present application at least include: by integrating the PA into the radio frequency front-end structure, the space occupation is reduced, and the production cost is also reduced. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly described below. Obviously, the described drawings are only part of the embodiments of the present application, not all embodiments, and those skilled in the art can obtain other design schemes and drawings from these drawings without creative labor.

[0042] FIG. 1 is a structural schematic diagram of the integrated PA radio frequency front-end structure according to the first aspect of the present application;

[0043] FIG. 2 is a preparation schematic diagram of the sound wave reflection layer 2 in the preparation method according to the second aspect of the present application;

[0044] FIG. 3 is a preparation schematic diagram of the filter bottom electrode 3 in the preparation method according to the second aspect of the present application;

[0045] FIG. 4 is a preparation schematic diagram of the filter piezoelectric layer 4 in the preparation method according to the second aspect of the present application;

[0046] FIG. 5 is a preparation schematic diagram of the filter top electrode 5 in the preparation method according to the second aspect of the present application;

[0047] FIG. 6 is a preparation schematic diagram of deep hole etching on the filter top electrode 5 in the preparation method according to the second aspect of the present application;

[0048] Figure 7 is a schematic diagram of the preparation of the deep hole for depositing the Mo metal layer in the preparation method of the second aspect of the present application;

[0049] Figure 8 is a schematic diagram of the preparation of the electromagnetic shielding layer 6 in the preparation method of the second aspect of the present application;

[0050] Figure 9 is a schematic diagram of the preparation of the first capacitor metal layer 7 in the preparation method of the second aspect of the present application;

[0051] Figure 10 is a schematic diagram of the preparation of the capacitor insulating layer 8 in the preparation method of the second aspect of the present application;

[0052] Figure 11 is a schematic diagram of the preparation of the second capacitor metal layer 9 in the preparation method of the second aspect of the present application;

[0053] Figure 12 is a schematic diagram of the preparation of the buffer layer 10 in the preparation method of the second aspect of the present application;

[0054] Figure 13 is a schematic diagram of the preparation of the channel layer 11 in the preparation method of the second aspect of the present application;

[0055] Figure 14 is a schematic diagram of the preparation of the barrier layer 12 in the preparation method of the second aspect of the present application;

[0056] Figure 15 is a schematic diagram of the preparation of the field effect transistor in the preparation method of the second aspect of the present application;

[0057] Figure 16 is a schematic diagram of the preparation after excavating the cavity in the preparation method of the second aspect of the present application;

[0058] Figure 17 is a schematic diagram of the preparation of filling the mesa isolation layer 16 in the preparation method of the second aspect of the present application;

[0059] Figure 18 is a schematic diagram of the preparation of the inductor metal layer 17 in the preparation method of the second aspect of the present application;

[0060] Figure 19 is a schematic diagram of the preparation of the inductor insulating layer 18 in the preparation method of the second aspect of the present application;

[0061] Figure 20 is a schematic diagram of the preparation of stacking the inductor metal layer 17 and the inductor insulating layer 18 in the preparation method of the second aspect of the present application;

[0062] Figure 21 is a schematic diagram of the preparation of the input pin 22, the ground pin 23 and the output pin 24 in the preparation method of the second aspect of the present application;

[0063] Figure 22 is a schematic diagram of the preparation of the solder joint 25 in the preparation method of the second aspect of the present application;

[0064] Figure 23 is a filter curve diagram of the radio frequency front end structure of the integrated PA;

[0065] Figure 24 is a GaN HEMT output characteristic curve of the integrated PA's RF front end structure.

[0066] Reference numerals: 1 - substrate, 2 - acoustic wave reflecting layer, 3 - filter bottom electrode, 4 - filter piezoelectric layer, 5 - filter top electrode, 6 - electromagnetic shielding layer, 7 - first capacitive metal layer, 8 - capacitive insulating layer, 9 - second capacitive metal layer, 10 - buffer layer, 11 - channel layer, 12 - barrier layer, 13 - source, 14 - gate, 15 - drain, 16 - mesa isolation layer, 17 - inductive metal layer, 18 - inductive insulating layer, 22 - input pin, 23 - ground pin, 24 - output pin, 25 - soldering point. DETAILED DESCRIPTION

[0067] This part will describe the specific embodiments of the present application in detail, the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part with graphics, so that people can intuitively and visually understand each technical feature and the overall technical solution of the present application, but it cannot be understood as a limitation on the protection scope of the present application.

[0068] In the description of the present application, it is understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right and the like, is based on the orientation or position relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application.

[0069] In the description of the present application, several meanings are one or more, and the meaning of multiple is more than two, greater than, less than, more than and the like are not included in the number, above, below, within and the like are understood to include the number. If it is described as first, second, it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0070] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting and the like should be understood broadly, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0071] In the background of pursuing miniaturization and high performance of electronic devices, monolithic integration of bulk acoustic wave filter and high electron mobility transistor (HEMT) based power amplifier (PA) becomes one of the focuses of key technologies in radio frequency front-end module. The integration of bulk acoustic wave filter and HEMT power amplifier can simplify the system design and layout of radio frequency front-end module, and also can reduce the manufacturing cost. This is particularly important for mass production. Reducing cost not only makes the integration technology more attractive, but also makes the product more competitive in the market.

[0072] Based on this concept, the present application proposes a radio frequency front-end structure integrated with PA and a preparation method thereof, which can make the radio frequency front-end structure integrated with PA occupy less space and reduce manufacturing cost.

[0073] Referring to FIG. 1, the radio frequency front-end structure integrated with PA in the first aspect embodiment of the present application includes a substrate 1, a BAW filter structure, an IPD MIM capacitor structure, a GaN HENT transistor structure and an IPD TGV inductor structure. Among them, the BAW filter structure is arranged on the substrate 1, the IPD MIM capacitor structure is arranged on the BAW filter structure, the GaN HENT transistor structure is arranged on the IPD MIM capacitor structure, and the IPD TGV inductor structure is arranged on the GaN HENT transistor structure.

[0074] Specifically, the material for preparing the substrate 1 is selected from silicon, sapphire, GaN, LiGaO2 or metal.

[0075] The BAW filter structure includes, from bottom to top, a sound wave reflection layer 2, a filter bottom electrode 3, a filter piezoelectric layer 4 and a filter top electrode 5, and the sound wave reflection layer 2 is stacked on the substrate 1. The preparation material of the filter bottom electrode 3 and the filter top electrode 5 is at least one of Al, Mo, W, Pt, Ti and Au.

[0076] The IPD MIM capacitor structure includes, from bottom to top, a first capacitor metal layer 7, a capacitor insulating layer 8 and a second capacitor metal layer 9.

[0077] Further, an electromagnetic shielding layer 6 is arranged between the BAW filter structure and the IPD MIM capacitor structure, and the electromagnetic shielding layer 6 is arranged between the first capacitor metal layer 7 and the filter top electrode 5, for reducing electromagnetic interference between the BAW filter structure and the IPD MIM capacitor structure.

[0078] The GaN HENT transistor structure includes a buffer layer 10, a channel layer 11, a barrier layer 12 and a field effect transistor stacked in sequence from bottom to top, and the field effect transistor includes a source electrode 13, a gate electrode 14 and a drain electrode 15. The GaN HENT transistor structure further includes a mesa isolation layer 16 arranged outside the channel layer 11, the barrier layer 12 and the field effect transistor.

[0079] The IPD TGV inductor structure includes an inductor metal layer 17 and an inductor insulating layer 18 stacked in sequence from bottom to top, and the inductor metal layer 17 and the inductor insulating layer 18 can be provided with multiple groups and stacked in sequence. The IPD TGV inductor structure is connected together with the GaN HENT transistor structure through a solder joint 25.

[0080] The second aspect of the application is a method for manufacturing the above-mentioned integrated PA RF front-end structure, comprising the following steps:

[0081] S100. Clean the substrate 1, which is a high-resistance silicon wafer, with acetone, anhydrous ethanol and water, and then clean it with H2SO4:H2O2:H2O (3:1:1) and HF:H2O (1:10) to remove silicon surface oxides and contaminants. Then clean it with deionized water for 10 minutes, and finally spin dry it in an HF solution with a concentration of 1.5% and place it in an oven for drying.

[0082] S200. Refer to FIG. 2, spin-coat and cure the substrate 1 surface to obtain the acoustic wave reflection layer 2. Specifically, apply a polyimide precursor solution on the substrate 1, and cure it under vacuum and at 350°C to form a polyimide film with a thickness of 9μm. Polyimide is a high-molecular polymer material with high acoustic impedance, which can effectively reflect bulk acoustic waves leaked from the BAW filter;

[0083] S300. Refer to FIG. 3, prepare the filter bottom electrode 3 on the surface of the cured acoustic wave reflection layer 2. Specifically, use a direct-current vacuum magnetron sputtering coating machine to sputter and deposit a layer of metal molybdenum (Mo) on the surface of the substrate after lithography as the filter bottom electrode 3. The filter top electrode 5 and the filter bottom electrode 3 are made of molybdenum (Mo) with a thickness of 100nm. Soak in acetone for 3 minutes to remove the metal on the photoresist to obtain the patterned filter bottom electrode 3.

[0084] S400. Refer to Fig. 4, the filter piezoelectric layer 4 is prepared by magnetron sputtering on the basis of the filter bottom electrode 3, and the specific process is as follows: adjusting the equipment parameters and target material, the chamber back pressure in the PVD wafer cavity is 5*10-7Torr, the AlN is sputtered and grown under the condition of AC power 6kw, Ar input speed 10sccm, N2 input speed 45sccm, and the thickness is 200nm; the sputtering gas is 99.9999% high-purity N2 and Ar, the purity of the sputtering Al target is 99.999%, and the Al target is also pre-sputtered and cleaned for 10 minutes before starting sputtering growth; the single-crystal AlN piezoelectric material can provide higher electromechanical coupling coefficient for the BAW filter, and ensure higher effective relative bandwidth;

[0085] S500. Refer to Fig. 5, the filter piezoelectric layer 4 is etched, and the filter top electrode 5 is prepared on the basis thereof, and the specific process is as follows: coating the filter piezoelectric layer 4 with adhesion promoter, spin coating photoresist, ultraviolet light exposure for 5s, and developing to obtain a sample with the filter top electrode 5; then, using a direct-current vacuum magnetron sputtering coating machine, sputtering and depositing a layer of metal molybdenum on the surface of the substrate after photolithography as the filter top electrode 5, the filter top electrode 5 usually adopts molybdenum, and the thickness is 100nm; soaking in acetone for 3min, and stripping the metal on the photoresist to obtain the patterned filter top electrode 5; thus, the BAW filter structure preparation is completed;

[0086] S600. Refer to Fig. 8, a layer of electromagnetic shielding layer 6 is laid on the surface of the filter top electrode 5, the wafer is heated to a process temperature of 350±10℃ before deposition, and the system is pumped to a low vacuum degree; thereafter, the workpiece surface is etched and cleaned with argon ions or metal ions; then, the arc layer is deposited, the aluminum oxide film is formed by PVD sputtering deposition of a metal target in a mixed atmosphere of argon and oxygen, and the electromagnetic shielding layer is laid between the acoustic element and the lumped electrical element to effectively improve the Q value of the lumped element (IPD capacitance and inductance are both lumped elements); then, the wafer is loaded into the PVD wafer cavity, the chamber back pressure is 5*10-7Torr, and Cu is sputtered and grown under the condition of AC power 5.2kw; thereafter, the Cu thin film is patterned by stripping, the via material usually adopts copper, and the thickness is 150nm; soaking in acetone for 5min, and stripping the metal on the photoresist to obtain the patterned aluminum oxide film;

[0087] S700. Refer to FIG. 9, a first capacitive metal layer 7 is prepared on the surface of the electromagnetic shielding layer 6, specifically, an adhesion promoter is coated on the surface of the prepared electromagnetic shielding layer 6, a photoresist is spin-coated, a pre-baking is performed to remove water vapor, an ultraviolet light exposure is performed for 5s, and the sample with capacitive shape is obtained by immersing in a developing solution for 40-60s; then, the wafer is loaded into a PVD carrier cavity with a back pressure of 5x10-7 Torr, and a Cu is sputtered under an AC power of 4kw; before the sputtering growth starts, the Cu target is pre-sputtered for 10 minutes; subsequently, the Cu thin film is patterned by lift-off, and the capacitive material is usually copper with a thickness of 100nm; the metal on the photoresist is removed by immersing in acetone for 3min to obtain the patterned first capacitive metal layer 7;

[0088] S800. Refer to FIG. 10, a capacitive insulating layer 8 is prepared on the surface of the first capacitive metal layer 7, specifically, a SiO2 is deposited on the surface of the first capacitive metal layer 7 by low-temperature CVD, and the deposition temperature of silane low-temperature oxidation is 400℃; the silane (SiH4) is thermally decomposed on the surface of the substrate in an oxygen-containing atmosphere, and reacts with oxygen to form SiO2, which is used as the capacitive insulating layer 8 of the MIM capacitor;

[0089] S900. Refer to FIG. 11, a second capacitive metal layer 9 is prepared on the surface of the capacitive insulating layer 8, specifically, a Cu thin film is deposited on the prepared SiO2 film by CVD, an adhesion promoter is coated on the surface of the prepared SiO2 film, a photoresist is spin-coated, a pre-baking is performed to remove water vapor, an ultraviolet light exposure is performed for 5s, and the patterned capacitive metal layer 9 is obtained by immersing in a developing solution for 40-60s; thus, the IPD MIM capacitor structure is prepared;

[0090] S1000. Refer to FIG. 12, a buffer layer 10 is prepared on the second capacitive metal layer 9 by metal organic chemical vapor deposition epitaxial growth;

[0091] S1100. Refer to FIG. 13, a channel layer 11 is prepared on the buffer layer 10 by metal organic chemical vapor deposition epitaxial growth;

[0092] S1200. Refer to FIG. 14, a barrier layer 12 is prepared on the channel layer by metal organic chemical vapor deposition epitaxial growth;

[0093] S1300. Refer to FIG. 15, a field effect transistor is prepared on the barrier layer 12, specifically, a metal layer in which a source electrode 13, a drain electrode 15 and a gate electrode 14 are deposited on the barrier layer 12 by electron beam evaporation deposition method, and the source electrode area, the gate electrode area and the drain electrode area are etched on the metal layer by inductively coupled plasma etching method, and then an annealing treatment is performed to finally obtain the source electrode 13, the gate electrode 14 and the drain electrode 15;

[0094] S1400. Refer to FIGS. 16 and 17, a cavity is etched on the side of the field effect tube by inductively coupled plasma etching, and a passivation material is filled in the cavity to obtain a mesa isolation layer 16, and the GaN HENT transistor structure is prepared.

[0095] S1500. Another substrate is prepared, refer to FIG. 18, an inductive metal layer 17 is obtained by spin coating and curing, specifically, a Cu thin film is deposited on a high resistance wafer by CVD, an adhesion promoter is coated on the surface of the prepared Cu thin film, a photoresist is spin coated, a front baking is performed to remove water vapor, an ultraviolet light exposure is performed for 5 s, and the sample with an inductive shape is obtained by immersing in a developing solution for 40-60 s; then, the wafer is loaded into a PVD loading chamber, the back pressure of the chamber is 5x10-7 Torr, and the Cu is sputtered under the condition of an AC power of 4 kw; before the sputtering growth starts, the Cu target is pre-sputtered and cleaned for 10 minutes; subsequently, the Cu thin film is patterned by stripping, the inductive material is usually copper, and the thickness is 100 nm; the metal on the photoresist is stripped by immersing in acetone for 3 min to obtain the patterned inductive metal layer 17.

[0096] S1600. SiO2 is deposited on the surface of the inductive metal layer 17 by low-temperature CVD, the deposition temperature of silane low-temperature oxidation is 400°C, silane (SiH4) is thermally decomposed on the surface of the substrate in an oxygen-containing atmosphere, and reacts with oxygen to generate SiO2.

[0097] S1700. Refer to FIG. 19, the inductive insulating layer 18 is prepared on the SiO2 thin film;

[0098] S1800. Refer to FIG. 20, the steps S1600 and S1700 are repeatedly performed, so that the multi-layer inductive metal layer 17 and the inductive insulating layer 18 are stacked in sequence, and the IPD TGV inductive structure is prepared;

[0099] S1900. Refer to FIG. 21, the inductive metal layer 17 is obtained by ICP etching through the substrate and photoetching stripping on the back side of the substrate, and the input pin 22, the ground pin 23 and the output pin 24 are obtained by PVD deposition of copper with a thickness of 100 nm;

[0100] S2000. Refer to FIG. 22, the wafer is inverted, and the solder joint 25 is prepared on the inductive metal layer 17, and the IPD TGV inductive structure is prepared;

[0101] S2100. The IPD TGV inductive structure is flipped, the IPD TGV inductive structure is combined with the GaN HENT transistor structure through the solder joint 25, and the integrated PA radio frequency front end structure is obtained.

[0102] Further, referring to FIGS. 6 and 7, after the filter top electrode 5 is completed, deep hole etching is performed on the filter top electrode 5, penetrating through the filter piezoelectric layer 4 to the filter bottom electrode 3, and a layer of Mo metal is deposited on the surface of the deep hole by physical vapor deposition, connecting the top and bottom electrodes of the two resonators, so that the two resonators are connected in series. If the above steps are not performed, the two resonators can be connected in series topology.

[0103] Referring to FIGS. 23 and 24, it can be seen from the curves that the effective relative bandwidth exceeds 300 MHz at the -3 dB frequency point, which is due to the use of single-crystal AlN as the piezoelectric material of the integrated PA radio frequency front-end structure, which maximizes the physical limit of AlN, and the near-band out-of-band rejection exceeds 35 dB, and the far-end rejection exceeds 55 dB.

[0104] The above is a specific description of the preferred embodiments of the present application, but the present application is not limited to the embodiments described above. Those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. An integrated PA radio frequency front end structure, characterized by Comprising: a substrate (1); a BAW filter structure, which is arranged on the substrate (1); an IPD MIM capacitor structure, which is arranged on the BAW filter structure; a GaN HENT transistor structure, which is arranged on the IPD MIM capacitor structure; an IPD TGV inductor structure, which is arranged on the GaN HENT transistor structure.

2. The integrated PA radio frequency front-end structure of claim 1, wherein: The BAW filter structure comprises, from bottom to top, a sound wave reflection layer (2), a filter bottom electrode (3), a filter piezoelectric layer (4), and a filter top electrode (5) stacked in sequence.

3. The integrated PA radio frequency front-end structure of claim 1, wherein: The IPD MIM capacitor structure comprises, from bottom to top, a first capacitor metal layer (7), a capacitor insulating layer (8), and a second capacitor metal layer (9) stacked in sequence.

4. The integrated PA radio frequency front-end structure of claim 1, wherein: An electromagnetic shielding layer (6) is arranged between the BAW filter structure and the IPD MIM capacitor structure.

5. The integrated PA radio frequency front-end structure of claim 1, wherein: The GaN HENT transistor structure comprises, from bottom to top, a buffer layer (10), a channel layer (11), a barrier layer (12), and a field effect transistor, which comprises a source electrode (13), a gate electrode (14), and a drain electrode (15).

6. The integrated PA radio frequency front-end structure of claim 5, wherein: The GaN HENT transistor structure further comprises a mesa isolation layer (16), which is arranged outside the channel layer (11), the barrier layer (12), and the field effect transistor.

7. The integrated PA radio frequency front-end structure of claim 1, wherein: The IPD TGV inductor structure comprises, from bottom to top, an inductor metal layer (17) and an inductor insulating layer (18) stacked in sequence.

8. The integrated PA radio frequency front-end structure of claim 1, wherein: The IPD TGV inductor structure and the GaN HENT transistor structure are connected together through a solder joint (25).

9. A method of manufacturing a radio frequency front end structure for the integrated PA of any of claims 1 to 8, characterized by, Comprising: cleaning the substrate (1); spinning and curing on the surface of the substrate (1) to obtain a sound wave reflection layer (2); preparing a filter bottom electrode (3) on the surface of the cured sound wave reflection layer (2); preparing a filter piezoelectric layer (4) on the filter bottom electrode (3) by magnetron sputtering; etching the filter piezoelectric layer (4) and preparing a filter top electrode (5) thereon, and the BAW filter structure is prepared; spreading an electromagnetic shielding layer (6) on the surface of the filter top electrode (5); preparing a first capacitor metal layer (7) on the surface of the electromagnetic shielding layer (6); preparing a capacitor insulating layer (8) on the surface of the first capacitor metal layer (7); preparing a second capacitor metal layer (9) on the surface of the capacitor insulating layer (8), and the IPD MIM capacitor structure is prepared; preparing a buffer layer (10) on the second capacitor metal layer (9) by metal organic chemical vapor deposition epitaxy; preparing a channel layer (11) on the buffer layer (10) by metal organic chemical vapor deposition epitaxy; preparing a barrier layer (12) on the channel layer by metal organic chemical vapor deposition epitaxy; preparing a field effect transistor on the barrier layer (12); ​ Etching a cavity on the side of the field effect tube, filling the cavity with passivation material to obtain a mesa isolation layer (16), and the GaN HENT transistor structure is prepared; Prepare another substrate, spin-coat and solidify to obtain an inductor metal layer (17); Depositing SiO2 on the surface of the inductor metal layer (17) by low-temperature CVD; Preparation of an inductor insulating layer (18) on the SiO2 film, and the IPD TGV inductor structure is prepared; Turn over the IPD TGV inductor structure, combine the IPD TGV inductor structure with the GaN HENT transistor structure through the solder joint (25), and obtain the integrated PA radio frequency front-end structure.

10. The method of claim 9, wherein: After the completion of the preparation of the filter top electrode (5), deep hole etching is performed on the filter top electrode (5), which penetrates through the filter piezoelectric layer (4) to the filter bottom electrode (3), and a layer of Mo metal is deposited on the surface of the deep hole by physical vapor deposition, connecting the top and bottom electrodes of the two resonators, so that the two resonators are connected in series.

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