KR20220154723A - A wireless communication infrastructure system consisting of a single crystal piezo resonator and filter structure using a thin film transfer process. - Google Patents

Abstract

A system for a wireless communications infrastructure using monocrystalline devices. A wireless system can include a power supply, a signal processing module, and a controller coupled to a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. Each of the transmit modules includes at least a transmit filter with one or more filter devices, while each of the receive modules includes at least a receive filter. Each of these filter devices includes a single crystal acoustic resonator device formed in a thin film transfer process with at least a first electrode material, a single crystal material, and a second electrode material. Wireless infrastructures using the present monocrystalline technology perform better in high power density applications, enable higher out of band rejection (OOBR), and also achieve higher linearity.

Description

A wireless communication infrastructure system consisting of a single crystal piezo resonator and filter structure using a thin film transfer process.

CROSS REFERENCES TO RELATED APPLICATIONS

This application claims priority to US Patent Application Serial No. 16/818,841, filed March 13, 2020.

In accordance with the present invention, techniques generally associated with electronic devices are provided. More specifically, the present invention relates to single crystal devices, bulk acoustic wave resonator devices, single crystal filter and resonator devices, power amplifiers (PAs), noise amplifiers (LNAs), Provides techniques for methods and devices for wireless communication systems using switches, and the like. By way of example only, the present invention has been applied to single crystal resonator devices for communication devices, mobile devices, computing devices, among others.

Mobile communication devices have been used successfully and efficiently all over the world. More than one billion mobile devices, including cell phones and smart phones, are manufactured each year, and unit volume continues to increase each year. With the ramp of 4G/LTE around 2012 and the explosion of mobile data traffic, data rich content is driving growth in the smartphone segment - expected to reach 2B per year in the next few years. do. The coexistence of new and legacy standards and the desire for higher data rate requirements are driving the complexity of wireless communication within smartphones. Unfortunately, there are limitations when using conventional wireless technology that are problematic and can lead to disadvantages in the future.

From the foregoing, it can be seen that techniques for improving electronic communication devices are strongly desired.

In accordance with the present invention, techniques related to electronic devices generally are provided. More specifically, the present invention relates to single crystal devices, bulk acoustic wave resonator devices, single crystal filter and resonator devices, power amplifiers (PAs), noise amplifiers (LNAs), switches, and Provides techniques for methods and devices for wireless communication systems using the like. By way of example only, the present invention has been applied to single crystal resonator devices for communication devices, mobile devices, computing devices, among others.

According to one example, the present invention provides a wireless communication infrastructure using monocrystalline devices. A wireless system can include a power supply, a signal processing module, and a controller coupled to a plurality of transceiver modules. Each of the transceiver modules includes a transmit module configured on a transmit path and a receive module configured on a receive path. Each of the transmit modules includes at least a transmit filter with one or more filter devices, while each of the receive modules includes at least a receive filter. In certain instances, the power source may include a power supply, a battery-based power supply, or a power supply coupled with a battery backup, or the like. The signal processing module may be a baseband signal processing module. Additionally, transceiver modules may include RF transmit and receive modules. Those skilled in the art will recognize other variations, modifications, and alternatives.

Each of these filter devices includes a single crystal acoustic resonator device. As an example, each device may include a substrate, a support layer, a piezoelectric film, a bottom electrode, a top electrode, a top metal, a first contact metal, and a second contact metal. The substrate includes a substrate surface area. The support layer is formed to overlie the substrate surface area and has air cavities formed therein. A piezoelectric film is formed to overlie the support layer and the substrate, and the piezoelectric film has contact vias formed therein. The bottom electrode is formed to lie under a portion of the piezoelectric film such that it is configured within the air cavity of the support layer and lies below the contact vias of the piezoelectric film. The top electrode is formed to overlie a portion of the piezoelectric film. The top metal is formed overlying a portion of the piezoelectric film so that it is configured within the contact vias of the piezoelectric film. A first contact metal is formed overlying a portion of the piezoelectric film such that it is electrically coupled to the top electrode. A second contact metal is formed overlying a portion of the piezoelectric film such that it is electrically coupled to the top metal and to the bottom electrode through the contact via of the piezoelectric film. As discussed above, there may be variations, modifications, and alternatives to these devices.

An antenna is coupled to each of the transmit modules and each of the receive modules. An antenna control module is coupled to each of the receive path, transmit path, and transceiver modules. This antenna control module is configured to select one of the receive paths or one of the transmit paths in enabling communication path operations.

In one example, a power amplifier module can be coupled to controller, power supply, and transceiver modules. A power amplifier module may be configured on each of the transmit paths and each of the receive paths. This power amplifier module may also include a plurality of communication bands, each of which may have a power amplifier. The filters of the transceiver modules may each be configured for one or more of the communication bands.

One or more advantages over existing techniques are achieved using the present invention. Wireless infrastructures using the present monocrystalline technology achieve better thermal conductivity, which enables these infrastructures to perform better in high power density applications. The present monocrystalline infrastructures also provide low loss, thus enabling higher out of band rejection (OOBR). With better thermal properties and resilience over higher power, these single crystal infrastructures also achieve higher linearity. Depending on the embodiment, one or more of these advantages may be achieved. Of course, other variations, modifications, and alternatives may exist.

A further understanding of the nature and advantages of the present invention may be obtained by reference to the accompanying drawings and portions of the detailed description that follow.

For a more complete understanding of the present invention, reference is made to the accompanying drawings. It is understood that these drawings are not to be regarded as limitations on the scope of the present invention, and that the presently described embodiments of the present invention and the presently understood best mode are described with additional details using the accompanying drawings. It should be.
1A is a simplified diagram illustrating an acoustic resonator device with top surface interconnections according to one embodiment of the present invention.
1B is a simplified diagram illustrating an acoustic resonator device with bottom surface interconnections according to one embodiment of the present invention.
1C is a simplified diagram illustrating an acoustic resonator device with interposer/cap-free structure interconnections according to an example of the present invention.
1D is a simplified diagram illustrating an acoustic resonator device having interposer/cap-free structure interconnections with a shared backside trench in accordance with one example of the present invention.
2 and 3 are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention.
4A is a simplified diagram illustrating steps for a method of creating a top surface micro-trench according to an example of the present invention.
4B and 4C are simplified diagrams illustrating alternative methods for performing the method step of forming a top surface micro-trench as described in FIG. 4A.
4D and 4E are simplified diagrams illustrating an alternative method for performing the method step of forming a top surface micro-trench as described in FIG. 4A.
5-8 are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention.
9A is a simplified diagram illustrating method steps for forming back surface trenches in accordance with one example of the present invention.
9B and 9C show an alternative method for performing the method step of singulating a seed substrate while simultaneously forming back surface trenches as described in FIG. 9A, in accordance with one embodiment of the present invention. These are simplified drawings illustrating.
10 is a simplified diagram illustrating method steps for forming the back surface metallization and electrical interconnections between the top and bottom surfaces of a resonator according to one example of the present invention.
11A and 11B are simplified diagrams illustrating alternative steps for a manufacturing method for an acoustic resonator device according to an example of the present invention.
12A-12E are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device using a blind via interposer according to an example of the present invention.
13 is a simplified diagram illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention.
14A-14G are simplified diagrams illustrating method steps for a cap wafer process for an acoustic resonator device according to an example of the present invention.
15A-15E are simplified diagrams illustrating method steps for making an acoustic resonator device with a shared back surface trench, which can be implemented with both interposer/cap and interposer free versions, according to examples of the present invention. drawings that have been
16A-16C-31A-31C show method steps for a transfer process using a sacrificial layer for single crystal acoustic resonator devices and various single crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views.
32A-32C-46A-46C are simplified diagrams illustrating method steps for a cavity coupled transfer process for single crystal acoustic resonator devices and various cross-sectional views of a single crystal acoustic resonator device according to an example of the present invention. admit.
47A-47C-59A-59C show method steps for a solidly mounted transfer process for single crystal acoustic resonator devices and various cross-sectional views of a single crystal acoustic resonator device according to an example of the present invention. These are simplified drawings illustrating them.
60A-60E are simplified circuit diagrams illustrating various monolithic single chip single crystal devices according to various examples of the invention.
61 is a simplified circuit diagram illustrating monolithic single chip single crystal device integrated multiple circuit functions in accordance with examples of the present invention.
62A-62E are simplified diagrams illustrating cross-sectional views of various monolithic single chip single crystal devices according to various examples of the present invention.
63 is a simplified flow chart illustrating a method for manufacturing an acoustic resonator device according to an example of the present invention.
64 is a simplified graph illustrating the results of forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention. The graph highlights the ability to tune the material's acoustic properties for a given aluminum mole fraction. This flexibility allows the resulting resonator properties to be tuned for individual applications.
65A is a simplified diagram illustrating a method for forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention.
65B is a simplified diagram illustrating a method for forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention.
65C is a simplified diagram illustrating a method for forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention.
66 is a simplified diagram illustrating a smart phone according to an example of the present invention.
67 is a simplified system diagram with a smart phone according to an example of the present invention.
68 is a simplified diagram of a smart phone system diagram according to an example of the present invention.
69 is a simplified diagram of a transmit module and a receive module according to examples of the invention.
70 is an example of a filter response in an example of the present invention.
71 is a simplified diagram of a smart phone RF power amplifier module according to an example of the present invention.
72 is a simplified diagram of a fixed wireless communications infrastructure system according to an example of the present invention.

In accordance with the present invention, techniques generally associated with electronic devices are provided. More specifically, the present invention relates to single crystal devices, bulk acoustic wave resonator devices, single crystal filter and resonator devices, power amplifiers (PAs), noise amplifiers (LNAs), switches, and Provides techniques for methods and devices for wireless communication systems using the like. By way of example only, the present invention has been applied to single crystal resonator devices for communication devices, mobile devices, computing devices, among others.

Typically, base stations provide connections for voice and data between mobile phones and the wider telephone network. These base stations are characterized as macro, micro, nano, pico, or femto, depending on the area of wireless coverage. Macro-cells are the base stations that cover the largest coverage of a service provider and are generally located in rural areas and near highways. Micro-cells are low-power base stations that cover areas where the mobile network needs additional coverage to maintain quality of service to subscribers. These micro-cells are generally located in suburban and urban areas. Pico-cells are smaller base stations that provide more localized coverage in areas with large numbers of users where network quality is poor. Pico-cells are generally located inside buildings. Macro base stations can have a range of up to 35 kilometers (about 22 miles). In comparison, pico-cells may have a range of 200 meters or less, and femto-cells may have a range of 10 to 40 meters.

These base stations operate at significantly higher power levels, especially compared to mobile devices. Mobile phones are typically capable of outputting 1 milliwatt (mW) to 1 watt (W), while base stations can output several watts to hundreds of watts. With smaller device sizes highly desirable in the industry (eg, smaller than 3x3 sq. mm for wireless infrastructure and smaller than 1.5x1.5 sq. mm for mobile devices), the wireless infrastructure requirements The power density, ie RF power per unit area, is also much higher than that of mobile devices. Monocrystalline devices have better thermal conductivity compared to conventional devices, which means that wireless infrastructures implementing monocrystalline devices, eg filters, are better suited for high power density operations.

Wireless infrastructures using monocrystalline devices benefit from higher out-of-band rejection (OOBR), which is the amount by which an undesired signal is attenuated relative to a desired signal. In wireless infrastructure filters, the specification for OOBR can be 10 to 20 dB stricter than for mobile device filters. Typically, filter designs require a trade-off between insertion loss and OOBR. Therefore, improving OOBR without deteriorating insertion loss requires a lower loss RF filter technology, i.e. single crystal RF filter technology.

The improved thermal conductivity of monocrystalline devices also enables present wireless infrastructures to operate with higher linearity. The root cause of non-linearity is any variation in the properties of device materials over temperature and power levels. According to examples of the present invention, a wireless infrastructure using monocrystalline devices achieves higher linearity due to improved thermal properties and consistency across higher power levels. The following paragraphs will generally describe the various components of wireless communication devices and their implementations in a system.

1A is a simplified diagram illustrating an acoustic resonator device 101 with top surface interconnections according to one embodiment of the present invention. As shown, device 101 includes a thinned seed substrate 112 having an overlying single crystal piezoelectric layer 120 with micro-vias 129 . The micro-via 129 may include a top micro-trench 121 , a top metal plug 146 , a back surface trench 114 , and a back surface metal plug 147 . Although device 101 is shown with a single micro-via 129, device 101 may have multiple micro-vias. A top metal electrode 130 is formed to overlie the piezoelectric layer 120 . The top cap structure is coupled to the piezoelectric layer 120 . This top cap structure includes one or more top bond pads 143, one or more bond pads 144, and one or more through-vias 151 connected to a top metal 145 having a top metal plug 146. It includes an interposer substrate 119 having a ). Solder balls 170 are electrically coupled to one or more top bonding pads 143 .

The thinned substrate 112 has first and second back surface trenches 113 and 114 . The back surface metal electrode 131 is formed to lie under a portion of the top surface metal electrode 130 , the first back surface trench 113 , and the thinned seed substrate 112 . A back surface metal plug 147 is formed to underlie the top surface metal 145 , the second back surface trench 114 , and a portion of the thinned seed substrate 112 . The back metal plug 147 is electrically coupled to the top metal plug 146 and the back metal electrode 131 . The back cap structure 161 is bonded to the thinned seed substrate 112 to lie under the first and second back surface trenches 113 and 114 . Additional details regarding the fabrication method of such a device will be discussed starting with FIG. 2 .

1B is a simplified diagram illustrating an acoustic resonator device 102 with rear surface interconnections according to one embodiment of the present invention. As shown, device 102 includes a thinned seed substrate 112 having an overlying piezoelectric layer 120 with micro-vias 129 . The micro-via 129 may include a top micro-trench 121 , a top metal plug 146 , a back surface trench 114 , and a back surface metal plug 147 . Although device 102 is shown with a single micro-via 129, device 102 may have multiple micro-vias. A top metal electrode 130 is formed to overlie the piezoelectric layer 120 . The top cap structure is coupled to the piezoelectric layer 120 . The top cap structure 119 includes one or more bond pads 144 on the piezoelectric layer 120 and bond pads connected to the top metal 145 . The top metal 145 includes a top metal plug 146 .

The thinned substrate 112 has first and second back surface trenches 113 and 114 . The back surface metal electrode 131 is formed to lie under a portion of the top surface metal electrode 130 , the first back surface trench 113 , and the thinned seed substrate 112 . A rear surface metal plug 147 is formed to underlie the top surface metal plug 146 , the second rear surface trench 114 , and a portion of the thinned seed substrate 112 . The rear metal plug 147 is electrically coupled to the top metal plug 146 . The back cap structure 162 is coupled to the thinned seed substrate 112 to underlie the first and second back surface trenches. One or more back surface bonding pads 171 , 172 , 173 are formed in one or more portions of back cap structure 162 . Solder balls 170 are electrically coupled to one or more back surface bonding pads 171-173. Additional details regarding the fabrication method of such a device will be discussed starting with FIG. 14A.

1C is a simplified diagram illustrating an acoustic resonator device with interposer/cap-free structure interconnections according to an example of the present invention. As shown, the device 103 includes a thinned seed substrate 112 having an overlying single crystal piezoelectric layer 120 with micro-vias 129 . The micro-via 129 may include a top micro-trench 121 , a top metal plug 146 , a back surface trench 114 , and a back surface metal plug 147 . Although device 103 is shown with a single micro-via 129, device 103 may have multiple micro-vias. A top metal electrode 130 is formed to overlie the piezoelectric layer 120 . The thinned substrate 112 has first and second back surface trenches 113 and 114 . The back surface metal electrode 131 is formed to lie under a portion of the top surface metal electrode 130 , the first back surface trench 113 , and the thinned seed substrate 112 . A back surface metal plug 147 is formed to underlie the top surface metal 145 , the second back surface trench 114 , and a portion of the thinned seed substrate 112 . The rear metal plug 147 is electrically coupled to the top metal plug 146 and the rear metal electrode 131 . Additional details regarding the fabrication method of such a device will be discussed starting with FIG. 2 .

1D is a simplified diagram illustrating an acoustic resonator device having interposer/cap-free structure interconnections with a shared backside trench in accordance with one example of the present invention. As shown, the device 104 includes a thinned seed substrate 112 having an overlying single crystal piezoelectric layer 120 with micro-vias 129 . The micro-via 129 may include a top micro-trench 121 , a top metal plug 146 , and a back metal 147 . Although device 104 is shown with a single micro-via 129, device 104 may have multiple micro-vias. A top metal electrode 130 is formed to overlie the piezoelectric layer 120 . The thinned substrate 112 has a first backside trench 113 . The back surface metal electrode 131 is formed to lie under a portion of the top surface metal electrode 130 , the first back surface trench 113 , and the thinned seed substrate 112 . A back surface metal 147 is formed to underlie the top surface metal 145 , the second back surface trench 114 , and a portion of the thinned seed substrate 112 . The back metal 147 is electrically coupled to the top metal plug 146 and the back metal electrode 131 . Additional details regarding the fabrication method of such a device will be discussed starting with FIG. 2 .

2 and 3 are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention. This method illustrates a process for fabricating an acoustic resonator similar to that shown in FIG. 1A. 2 may represent method steps for providing a partially processed piezoelectric substrate. As shown, the device 200 includes a seed substrate 110 having a piezoelectric layer 120 formed thereon. In a particular example, the seed substrate may include silicon (Si), silicon carbide (SiC), aluminum oxide (AlO), or monocrystalline aluminum gallium nitride (GaN) materials, or the like. In certain instances, SiC substrates may provide better thermal conductivity, which may be desirable depending on the application. The piezoelectric layer 120 may include a piezoelectric single crystal layer or a thin film piezoelectric single crystal layer.

As shown in device 300 , FIG. 3 may represent method steps for forming top surface metallization or top resonator metal electrode 130 . In certain examples, the top metal electrode 130 may include a molybdenum, aluminum, ruthenium, or titanium material, or the like, and combinations thereof. This layer may be deposited and patterned on top of the piezoelectric layer by a lift-off process, a wet etch process, a dry etch process, a metal printing process, a metal lamination process, or the like. The lift-off process may include a sequential process of lithographic patterning, metal deposition, and lift-off steps to create a top metal layer. Wet/dry etching processes may include sequential processes of metal deposition, lithographic patterning, metal deposition, and metal etching steps to create a top metal layer. Those skilled in the art will recognize other variations, modifications, and alternatives.

4A is a simplified diagram illustrating steps for a manufacturing method for an acoustic resonator device 401 according to an example of the present invention. These figures may represent method steps for forming one or more top surface micro-trenches 121 in a portion of the piezoelectric layer 120 . This top surface micro-trench 121 may serve as the primary interconnection junction between the top and bottom surfaces of an acoustic membrane, which will be developed in later method steps. In one example, the top micro-trench 121 extends completely through the piezoelectric layer 120 and stops at the seed substrate 110 . These top surface micro-trenches 121 may be formed through a dry etching process, a laser drilling process, or the like. 4b and 4c describe these options in more detail.

4B and 4C are simplified diagrams illustrating alternative methods for performing a method step as described in FIG. 4A. As shown with device 402 , FIG. 4B shows method steps using a laser drill that can quickly and accurately form a top surface micro-trench 121 in piezoelectric layer 120 . In one example, a laser drill drills holes between 10 um and 500 um in diameter, or nominally 50 um holes, through the piezoelectric layer 120 and stopping in the seed substrate 110 below the interface between the layers 120 and 110. can be used to form A protective layer 122 may be formed to overlie the piezoelectric layer 120 and the top metal electrode 130 . This protective layer 122 may serve to protect the device from laser debris and provide a mask against etching of the top micro-vias 121 . In a specific example, the laser drill may be an 11 W high power diode-pumped UV laser, or similar. This mask 122 can then be removed before proceeding to other steps. This mask can also be omitted from the laser drilling process and an air flow can be used to remove the laser fragments.

4C may represent method steps for using a dry etching process to form top surface micro-trenches 121 in piezoelectric layer 120 . As shown by device 403 , a lithographic masking layer 123 may be formed overlying piezoelectric layer 120 and top metal electrode 130 . The top micro-trench 121 may be formed by exposure to plasma, or the like.

4D and 4E are simplified diagrams illustrating an alternative method for performing a method step as described in FIG. 4A. These figures may represent method steps for simultaneously fabricating multiple acoustic resonator devices. In FIG. 4D , two devices are shown on die #1 and die #2 of wafer 404 , respectively. 4E shows the process of forming a micro-via 121 on each of these dies of wafer 405 while also etching a scribe line 124 or dicing line. In one example, etching of the scribe line 124 singulates the piezoelectric single crystal layer 120 and relieves stress therein.

5-8 are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention. As shown with device 500 , FIG. 5 illustrates method steps for forming one or more bond pads 140 and forming a top metal 141 electrically coupled to at least one of bond pads 140 . can indicate The top metal 141 may include a top metal plug 146 formed in the top micro-trench 121 . In a particular example, top metal plug 146 fills top micro-trench 121 to form a top portion of a micro-via.

In one example, bond pads 140 and top metal 141 may include a gold material or other interconnect metal material depending on the application of the device. These metal materials may be formed by a lift-off process, a wet etch process, a dry etch process, a metal printing process, or the like. In a specific example, the deposited metal materials can also serve as bond pads to a cap structure, which will be described below.

6 may represent method steps for preparing an acoustic resonator device for coupling, which may be a hermetic coupling. As shown with device 600, the top cap structure is placed over an acoustic resonator device that has been partially processed as described in previous figures. The top cap structure may be formed using the interposer substrate 119 in two configurations: fully processed interposer version 601 (through glass vias) and partially processed interposer version 602 (blind via version). In the 601 version, interposer substrate 119 includes through-via structures 151 that extend through interposer substrate 119 and are electrically coupled to bottom bond pads 142 and top bond pads 143. includes In the 602 version, the interposer substrate 119 includes blind via structures 152 that extend from the bottom through only a portion of the interposer substrate 119 . These blind via structures 152 are also electrically coupled to bottom bond pads 142 . In certain examples, the interposer substrate may include silicon, glass, smart-glass, or other similar materials.

7 may represent method steps for coupling a top cap structure to a partially processed acoustic resonator device. As shown by device 700, interposer substrate 119 is formed by bonding pads 140, 142 and top metal 141, now indicated as bond pad 144 and top metal 145, to a piezoelectric layer. coupled to This bonding process may be accomplished using a compression bonding method or the like. As shown with device 800 , FIG. 8 may represent method steps for thinning a seed substrate 110 , now indicated as thinned seed substrate 111 . This substrate thinning process may include grinding and etching processes or the like. In a specific example, this process may include a wafer backgrinding process followed by stress relief, which may involve dry etching, CMP polishing, or annealing processes.

9A is a simplified diagram illustrating steps for a manufacturing method for an acoustic resonator device 901 according to an example of the present invention. 9A may represent method steps for forming backside trenches 113 and 114 to enable access to the piezoelectric layer from the backside of the thinned seed substrate 111 . In one example, the first back surface trench 113 may be formed within the thinned seed substrate 111 and underlying the top metal electrode 130 . A second back surface trench 114 may be formed within the thinned seed substrate 111 and underlying the top surface micro-trench 121 and top surface metal plug 146 . This substrate is now denoted as thinned substrate 112 . In a particular example, these trenches 113 and 114 may be formed using deep reactive ion etching (DRIE) processes, Bosch processes, or the like. The size, shape, and number of trenches may vary depending on the design of the acoustic resonator device. In various examples, the first back surface trench may be formed to have a top metal electrode shape or a trench shape similar to that of the back surface metal electrode. The first back surface trench may also be formed with a trench shape different from the shape of both the top surface metal electrode and the back surface metal electrode.

9B and 9C are simplified diagrams illustrating an alternative method for performing a method step as described in FIG. 9A. Like FIGS. 4D and 4E , these figures may represent method steps for simultaneously fabricating multiple acoustic resonator devices. In FIG. 9B , two devices with cap structures are shown on die #1 and die #2 of wafer 902 , respectively. 9C shows the process of forming back surface trenches 113 and 114 on each of these dies of wafer 903 while also etching a scribe line 115 or dicing line. In one example, etching of the scribe line 115 provides an optional method for singulating the backside wafer 112 .

10 is a simplified diagram illustrating steps for a manufacturing method for an acoustic resonator device 1000 according to an example of the present invention. These figures may represent method steps for forming a back surface metal electrode 131 and a back surface metal plug 147 in the back surface trenches of the thinned seed substrate 112 . In one example, the back surface metal electrode 131 is formed within the first back surface trench 113 to overlie the top surface metal electrode 130 and to underlie one or more portions of the thinned substrate 112 . It can be. This process completes the resonator structure within the acoustic resonator device. A back surface metal plug 147 may be formed within the second back surface trench 114 , under the top surface micro-trench 121 , and under one or more portions of the thinned substrate 112 . The rear metal plug 147 may be electrically coupled to the top metal plug 146 and the rear metal electrode 131 . In certain examples, the rear metal electrode 130 may include molybdenum, aluminum, ruthenium, or titanium material, or the like, and combinations thereof. The rear metal plug may include gold material, low resistivity interconnect metals, electrode metals, or the like. These layers may be deposited using the deposition methods described above.

11A and 11B are simplified diagrams illustrating alternative steps for a manufacturing method for an acoustic resonator device according to an example of the present invention. These figures show methods of bonding the back cap structure to lie underneath the thinned seed substrate 112 . In the device 1101 of FIG. 11A , the back cap structure is a dry film cap 161 that may include a permanent photo-imageable dry film such as solder mask, polyimide, or the like. )to be. Joining such a cap structure is cost-effective and reliable, but may not create a hermetic seal. In the device 1102 of FIG. 11B , the back cap structure is a substrate 162 that may include silicon, glass, or other similar material. Bonding these substrates can provide a hermetic seal, but can be more expensive and require additional processes. Depending on the application, one of these backside cap structures can be combined to underlie the first and second backside vias.

12A-12E are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention. More specifically, these figures describe additional steps for processing the blind via interposer “602” version of the top cap structure. 12A shows an acoustic resonator device 1201 with blind vias 152 in the top cap structure. In device 1202 of FIG. 12B , interposer substrate 119 is thinned, which forms a thinned interposer substrate 118 for exposing blind vias 152 . This thinning process may be a combination of a grinding process and an etching process as described for thinning the seed substrate. In the device 1203 of FIG. 12C , the redistribution layer (RDL) process and the metallization process form a top cap bonding pad overlying and electrically coupled to the blind vias 152. s (160). As shown in device 1204 of FIG. 12D , a ball grid array (BGA) process involves placing solder balls overlying and electrically coupled to top cap bonding pads 160 . 170) can be applied to form. This process leaves the acoustic resonator device ready for wire coupling 171 , as shown by device 1205 in FIG. 12E .

13 is a simplified diagram illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention. As shown, device 1300 includes two fully processed acoustic resonator devices ready to singulate to create separate devices. In one example, the die singulation process may be accomplished using a wafer dicing sawing process, a laser cutting singulation process, or other processes and combinations thereof.

14A-14G are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention. This method illustrates a process for fabricating an acoustic resonator similar to that shown in FIG. 1B. The method for this example of an acoustic resonator may go through steps similar to those described in FIGS. 1-5. 14A (device 1401) shows how this method differs from that described above. Here, the top cap structure substrate 119 includes only one layer of metallization with one or more bottom bond pads 142 . Compared to FIG. 6, there are no via structures in the top cap structure since the interconnections will be formed on the underside of the acoustic resonator device.

14B-14F show method steps similar to those described in the first process flow. 14B (device 1402) now shows top metal 145 with top metal plug 146 and top metal pads 140, 142 and top metal 141, denoted as bonding pads 144. Through this, steps of a method of coupling the top cap structure to the piezoelectric layer 120 may be indicated. FIG. 14C (device 1403 ) may represent a method step for thinning a seed substrate 110 , forming a thinned seed substrate 111 , similar to that described in FIG. 8 . 14D (device 1404) may represent method steps for forming first and second back surface trenches similar to those described in FIG. 9A. 14E (device 1405) may represent method steps for forming a back metal electrode 131 and a back metal plug 147, similar to those described in FIG. 10 . 14F (device 1406) can represent method steps for bonding the back cap structure 162, similar to those described in FIGS. 11A and 11B.

14G (device 1407) shows another step different from the process flow described above. Here, the rear bonding pads 171 , 172 , and 173 are formed in the rear cap structure 162 . In one example, these backside bond pads 171-173 may be formed through masking, etching, and metal deposition processes similar to those used to form other metal materials. A BGA process may be applied to form solder balls 170 that contact these backside bonding pads 171-173, which prepares the acoustic resonator device 1407 for wire bonding.

15A-15E are simplified diagrams illustrating steps for a manufacturing method for an acoustic resonator device according to an example of the present invention. This method illustrates a process for fabricating an acoustic resonator similar to that shown in FIG. 1B. The method for this example may undergo steps similar to those described in FIGS. 1-5 . 15A (device 1501) shows the differences of this method from that described above. A temporary carrier 218 having a layer of temporary adhesive 217 is attached to the substrate. In certain examples, the temporary carrier 218 may include a glass wafer, silicon wafer, or other wafer and the like.

15B-15F show method steps similar to those described in the first process flow. FIG. 15B (device 1502 ) may represent method steps for thinning a seed substrate 110 , forming a thinned substrate 111 similar to that described in FIG. 8 . In certain examples, thinning of the seed substrate 110 may include a backside grinding process followed by a stress relief process. The stress relief process may include dry etching, chemical mechanical planarization (CMP), and annealing processes.

15C (device 1503) may represent method steps for forming the shared back surface trench 113, similar to the techniques described in FIG. 9A. The main difference is that the shared back surface trench is configured to underlie all of the top metal electrode 130 , the top micro-trench 121 , and the top metal plug 146 . In one example, the shared back surface trench 113 is a back surface resonator that can vary in size, shape (all possible geometries), and sidewall profile (tapered convex, tapered concave, or right angle). is a cavity In a particular example, formation of the shared back surface trench 113 may include a litho-etch process that may include back-to-front alignment and dry etching of the back surface substrate 111. . The piezoelectric layer 120 may serve as an etch stop layer for forming the shared back surface trench 113 .

15D (device 1504) may represent method steps for forming back surface metal electrode 131 and back surface metal 147, similar to those described in FIG. 10 . In one example, formation of the back surface metal electrode 131 may include deposition and patterning of metal materials within the shared back surface trench 113 . Here, back surface metal 131 serves as the electrode in micro-via 121 and back surface plug/connection metal 147 . The thickness, shape, and type of metal can vary as a function of resonator/filter design. As an example, the back electrode 131 and the via plug metal 147 may be different metals. In a particular example, these backside metals 131 and 147 may be deposited and patterned on the surface of the piezoelectric layer 120 or routed back to the backside of the substrate 112 . In one example, the back surface metal electrode may be patterned such that it is configured within the boundaries of the shared back surface trench such that the back surface metal electrode does not come into contact with one or more sidewalls of the seed substrate created while forming the shared back surface trench. can

15E (device 1505) is shown in FIGS. 11A and 11B after de-bonding of the temporary carrier 218 to remove the temporary adhesive 217 and cleaning the top surface of the device. Similar method steps for assembling the rear cap structure 162 may be presented. Those skilled in the art will recognize other variations, modifications, and alternatives to the method steps described above.

As used herein, the term “substrate” may refer to a bulk substrate, or aluminum, gallium, or ternary compounds of aluminum and gallium and nitrogen, combinations, and the like comprising epitaxial regions, or functional regions. It may include overlying growth structures such as those.

One or more advantages over existing techniques are achieved using the present invention. Specifically, the device can be fabricated in a relatively simple and cost effective manner using conventional materials and/or methods according to one of the techniques common in the art. Using this method, it is possible to create a reliable single crystal based acoustic resonator using multiple methods of 3-dimensional stacking via a wafer level process. These filters or resonators may be implemented within an RF filter device, RF filter system, or the like. Depending on the embodiment, one or more of these advantages may be achieved. Of course, other variations, modifications, and alternatives may exist.

As 4G LTE and 5G become more popular day by day, wireless data communication requires high performance RF filters with frequencies around 5 GHz and higher. Bulk acoustic wave resonators (BAWRs), which are widely used in such filters operating at frequencies of about 3 GHz and below, are leading candidates for meeting these needs. Current bulk acoustic wave resonators use polycrystalline piezoelectric AlN thin films, in which the c-axis of each grain is aligned perpendicular to the surface of the film, allowing high piezoelectric performance, while the a- or b-axis of the grain -Axes are randomly distributed. This particular grain distribution works well when the thickness of the piezoelectric film is about 1 μm and greater, which is perfect for bulk acoustic wave (BAW) filters operating at frequencies ranging from 1 to 3 GHz. is the thickness However, the quality of polycrystalline piezoelectric films degrades rapidly as thicknesses decrease below about 0.5 um required for resonators and filters operating at frequencies of about 5 GHz and above.

Monocrystalline or epitaxial piezoelectric thin films grown on compatible crystalline substrates exhibit good crystalline quality and high piezoelectric performance even at very thin thicknesses, for example 0.4 um. The present invention provides fabrication processes and structures for high quality bulk acoustic wave resonators with monocrystalline or epitaxial piezoelectric thin films for high frequency BAW filter applications.

BAWRs require a piezoelectric material, eg AlN, in crystalline form, ie polycrystalline or monocrystalline form. The quality of a film strongly depends on the chemical, crystalline, or topographical quality of the layer on which the film is grown. In conventional BAWR processes (including film bulk acoustic resonator (FBAR) or solidly mounted resonator (SMR) geometry), a piezoelectric film is grown on a patterned bottom electrode and , which is usually made of molybdenum (Mo), tungsten (W), or ruthenium (Ru). The surface geometry of the patterned bottom electrode greatly affects the crystalline orientation and crystalline quality of the piezoelectric film, which requires complex modification of the structure.

Accordingly, the present invention uses monocrystalline piezoelectric films and thin film transfer processes to create a BAWR with improved ultimate quality factor and electro-mechanical coupling to RF filters. These methods and structures enable fabrication methods and structures for RF filters using monocrystalline or epitaxial piezoelectric films to meet the growing demands of modern data communications.

In one example, the present invention provides transfer structures and processes for acoustic resonator devices, which provide a planar, high-quality, monocrystalline piezoelectric film for high Q and excellent acoustic wave control at high frequencies. As explained above, polycrystalline piezoelectric layers limit Q at high frequencies. Also, growing epitaxial piezoelectric layers on patterned electrodes affects the crystalline orientation of the piezoelectric layer, which limits the ability of the resulting resonators to have tight boundary control. As described further below, embodiments of the present invention may overcome these limitations and exhibit improved performance and cost-effectiveness.

16A-16C-31A-31C illustrate a fabrication method for an acoustic resonator device using a transfer structure with a sacrificial layer. In this series of figures described below, the "a" figures are simplified views illustrating a top cross-sectional view of a single crystal resonator device in accordance with various embodiments of the present invention. The "b" figures show simplified diagrams illustrating longitudinal cross-sections of the same devices in the "a" figures. Likewise, the "c" figures show simplified diagrams illustrating transverse cross-sectional views of the same devices in the "a" figures. In some cases, certain features are omitted to emphasize other features and relationships between these features. Those skilled in the art will recognize variations, modifications, and alternatives to the examples shown in this series of figures.

16A-16C (devices 1601-1603, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming a piezoelectric film 1620 to overlie a growth substrate 1610 . In one example, the growth substrate 1610 may include silicon (S), silicon carbide (SiC), or other similar materials. The piezoelectric film 1620 may be an epitaxial film comprising aluminum nitride (AlN), gallium nitride (GaN), or other similar materials. Additionally, such piezoelectric substrates may undergo a thickness trim.

17A-17C (devices 1701-1703, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming the first electrode 1710 to overlie the surface area of the piezoelectric film 1620 . In one example, the first electrode 1710 may include molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials. In a specific example, the first electrode 1710 may undergo dry etching with a gradient. In one example, the slope may be about 60 degrees.

18A-18C (devices 1801-1803, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices according to an example of the present invention and various single-crystal acoustic resonator devices. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming a first passivation layer 1810 to overlie the first electrode 1710 and the piezoelectric film 1620 . In one example, the first passivation layer 1810 may include silicon nitride (SiN), silicon oxide (SiO), or other similar materials. In a specific example, the first passivation layer 1810 can have a thickness ranging from about 50 nm to about 100 nm.

19A-19C (devices 1901-1903, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming a sacrificial layer 1910 overlying a portion of the first electrode 1810 and a portion of the piezoelectric film 1620 . In one example, the sacrificial layer 1910 may include polycrystalline silicon (poly-Si), amorphous silicon (a-Si), or other similar materials. In a specific example, this sacrificial layer 1910 may undergo a dry etch with a gradient and may be deposited to a thickness of about 1 um. Additionally, phosphorus-doped SiO ₂ (PSG) can be used as a sacrificial layer with different combinations of support layers (eg, SiN _x ).

20A-20C (devices 2001-2003, respectively) show method steps for a transfer process using a sacrificial layer for single crystal acoustic resonator devices and various single crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming the support layer 2010 to overlie the sacrificial layer 1910 , the first electrode 1710 , and the piezoelectric film 1620 . In one example, the support layer 2010 may include silicon dioxide (SiO ₂ ), silicon nitride (SiN), or other similar materials. In a specific example, this support layer 2010 may be deposited to a thickness of about 2-3 um. As described above, other support layers (eg SiN _x ) may be used in the case of the PSG sacrificial layer.

21A-21C (devices 2101-2103, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for polishing support layer 2010 to form polished support layer 2011 . In one example, the polishing process may include a chemical-mechanical planarization process or the like.

22A-22C (devices 2201-2203, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate turning the device over and physically bonding the overlying support layer 2011 to overlie the bonded substrate 2210 . In one example, the bonding substrate 2210 is a bonding support layer overlying a substrate having silicon (Si), sapphire (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), silicon carbide (SiC), or other similar materials. 2220) (SiO ₂ or similar material). In certain embodiments, bonded support layer 2220 of bonding substrate 2210 is physically bonded to polished support layer 2011 . Additionally, the physical bonding process may include a room temperature bonding process followed by a 300 degree Celsius annealing process.

23A-23C (devices 2301-2303, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate the method steps of removing the growth substrate 1610 or otherwise transferring the piezoelectric film 1620 . In one example, the removal process may include a grinding process, a blanket etch process, a film transfer process, an ion implantation transfer process, a laser crack transfer process, or the like, and combinations thereof.

24A-24C (devices 2401-2403, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures form an electrode contact via 2410 in a piezoelectric film 1620 (which becomes the piezoelectric film 1621) to overlie the first electrode 1710, and overlying the sacrificial layer 1910. The method step of forming one or more release holes 2420 in the piezoelectric film 1620 and the first passivation layer 1810 to be Via formation processes can include various types of etching processes.

25A-25C (devices 2501-2503, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming the second electrode 2510 to overlie the piezoelectric film 1621 . In one example, formation of the second electrode 2510 may be accomplished by depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials; and then etching the second electrode 2510 to form the electrode cavity 2511 and to remove the portion 2511 from the second electrode to form the top metal 2520 . Additionally, top metal 2520 is physically coupled to first electrode 1720 via electrode contact via 2410 .

26A-26C (devices 2601-2603, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures form a first contact metal 2610 to overlie a portion of the second electrode 2510 and a portion of the piezoelectric film 1621, and a portion of the top metal 2520. and a method step of forming the second contact metal 2611 to overlie a portion of the piezoelectric film 1621 . In one example, the first and second contact metals are gold (Au), aluminum (Al), copper (Cu), nickel (Ni), aluminum bronze (AlCu), or related alloys of these materials, or other Similar materials may be included.

27A-27C (devices 2701-2703, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming a second passivation layer 2710 to overlie the second electrode 2510 , the top metal 2520 , and the piezoelectric film 1621 . In one example, the second passivation layer 2710 may include silicon nitride (SiN), silicon oxide (SiO), or other similar materials. In certain examples, the second passivation layer 2710 can have a thickness ranging from about 50 nm to about 100 nm.

28A-28C (devices 2801-2803, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for removing the sacrificial layer 1910 to form the air cavity 2810 . In one example, the removal process may include a poly-Si etch or an a-Si etch, or the like.

29A-29C (devices 2901-2903, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for processing second electrode 2510 and top metal 2520 to form processed second electrode 2910 and processed top metal 2920 . This step may follow the formation of second electrode 2510 and top metal 2520 . In one example, processing these two components may include depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar material; and then etching (eg, dry etching or the like) these materials to form a processed second electrode 2910 with an electrode cavity 2912 and a processed top metal 2920 . The processed top metal 2920 remains separated from the processed second electrode 2910 by the removal of portion 2911 . In a specific example, the processed second electrode 2910 is characterized by the addition of an energy confinement structure configured on the processed second electrode 2910 to increase Q.

30A-30C (devices 3001-3003, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for processing the first electrode 1710 to form the processed first electrode 2310 . This step may follow formation of the first electrode 1710 . In one example, processing of these two components may include depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials; and then etching (eg, dry etching or the like) this material to form a processed first electrode 3010 having an electrode cavity, similar to the processed second electrode 2910. do. Air cavity 2811 shows the change in cavity shape due to the processed first electrode 3010 . In a particular example, the processed first electrode 3010 is characterized by the addition of an energy confinement structure configured on the processed second electrode 3010 to increase Q.

31A-31C (devices 3101-3103, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures show a first electrode 1710 to form a processed first electrode 2310 and a second electrode to form a processed second electrode 2910/processed top metal 2920. The method steps for processing the electrode 2510/top metal 2520 are illustrated. These steps may follow the formation of each individual electrode as described with respect to FIGS. 29A-29C and 30A-30C. Those skilled in the art will recognize other variations, modifications, and alternatives.

32A-32C-46A-46C illustrate a fabrication method for an acoustic resonator device using a transfer structure without a sacrificial layer. In this series of figures described below, “a” figures are simplified figures illustrating a top cross-sectional view of a single crystal resonator device according to various embodiments of the present invention. The "b" figures show simplified diagrams illustrating longitudinal cross-sections of the same devices in the "a" figures. Likewise, the "c" figures show simplified diagrams illustrating transverse cross-sectional views of the same devices in the "a" figures. In some cases, certain features are omitted to emphasize other features and relationships between these features. Those skilled in the art will recognize variations, modifications, and alternatives to the examples shown in this series of figures.

32A-32C (devices 3201-3203, respectively) are simplified diagrams illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming a piezoelectric film 3220 to overlie a growth substrate 3210 . In one example, the growth substrate 3210 may include silicon (S), silicon carbide (SiC), or other similar materials. The piezoelectric film 3220 may be an epitaxial film comprising aluminum nitride (AlN), gallium nitride (GaN), or other similar materials. Additionally, such piezoelectric substrates may undergo thickness trimming.

33A-33C (devices 3301-3303, respectively) are simplified diagrams illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming the first electrode 3310 to overlie the surface area of the piezoelectric film 3220 . In one example, the first electrode 3310 may include molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials. In a specific example, the first electrode 3310 may undergo dry etching with a gradient. In one example, the slope may be about 60 degrees.

34A-34C (devices 3401-3403, respectively) are simplified diagrams illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming a first passivation layer 3410 to overlie the first electrode 3310 and the piezoelectric film 3220 . In one example, the first passivation layer 3410 may include silicon nitride (SiN), silicon oxide (SiO), or other similar materials. In a specific example, the first passivation layer 3410 can have a thickness ranging from about 50 nm to about 100 nm.

35A-35C (devices 3501-3503, respectively) are simplified illustrations illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming a support layer 3510 to overlie the first electrode 3310 and the piezoelectric film 3220 . In one example, the support layer 3510 may include silicon dioxide (SiO ₂ ), silicon nitride (SiN), or other similar materials. In a specific example, this support layer 3510 may be deposited to a thickness of about 2-3 um. As described above, other support layers (eg SiN _x ) may be used in the case of the PSG sacrificial layer.

36A-36C (devices 3601-3603, respectively) are simplified illustrations illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate the optional method steps of processing support layer 3510 (to form support layer 3511) within region 3610. In one example, processing may include partial etching of the support layer 3510 to create a planar bonding surface. In certain examples, processing may include a cavity region. In other examples, this step may be replaced with polishing processes such as a chemical-mechanical planarization process or the like.

37A-37C (devices 3701-3703, respectively) are simplified illustrations illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming an air cavity 3710 within a portion of support layer 3511 (to form support layer 3512). In one example, cavity formation may include an etching process stopping at the first passivation layer 3410 .

38A-38C (devices 3901-3903, respectively) are simplified diagrams illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming one or more cavity vent holes 3810 in a portion of the piezoelectric film 3220 through the first passivation layer 3410 . In one example, cavity vent holes 3810 connect to air cavity 3710.

39A-39C (devices 3901-3903, respectively) are simplified diagrams illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate turning the device over and physically bonding the overlying support layer 3512 to overlie the bonding substrate 3910 . In one example, the bonded substrate 3910 is a bonded support layer overlying a substrate having silicon (Si), sapphire (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), silicon carbide (SiC), or other similar materials. 3920) (SiO ₂ or similar material). In certain embodiments, bonded support layer 3920 of bonding substrate 3910 is physically bonded to polished support layer 3512 . Additionally, the physical bonding process may include a room temperature bonding process followed by a 300 degree Celsius annealing process.

40A-40C (devices 4001-4003, respectively) are simplified illustrations illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate the method steps of removing the growth substrate 3210 or otherwise transferring the piezoelectric film 3220 . In one example, the removal process may include a grinding process, a blanket etch process, a film transfer process, an ion implantation transfer process, a laser crack transfer process, or the like, and combinations thereof.

41A-41C (devices 4101-4103, respectively) are simplified illustrations illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming an electrode contact via 4110 in the piezoelectric film 3220 to overlie the first electrode 3310 . Via formation processes can include various types of etching processes.

42A-42C (devices 4201-4203, respectively) are simplified diagrams illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures illustrate method steps for forming the second electrode 4210 to overlie the piezoelectric film 3220 . In one example, formation of the second electrode 4210 may be accomplished by depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials; and then etching the second electrode 4210 to form the electrode cavity 4211 and to remove the portion 4211 from the second electrode to form the top metal 4220 . Additionally, top metal 4220 is physically coupled to first electrode 3310 via electrode contact via 4110 .

43A-43C (devices 4301-4303, respectively) are simplified diagrams illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to an example of the present invention. drawings that have been As shown, these figures form a first contact metal 4310 to overlie a portion of the second electrode 4210 and a portion of the piezoelectric film 3220, and a portion of the top metal 4220. and method steps of forming the second contact metal 4311 to overlie a portion of the piezoelectric film 3220. In one example, the first and second contact metals may include gold (Au), aluminum (Al), copper (Cu), nickel (Ni), aluminum bronze (AlCu), or other similar materials. These figures also illustrate method steps for forming a second passivation layer 4320 to overlie the second electrode 4210 , the top metal 4220 , and the piezoelectric film 3220 . In one example, the second passivation layer 4320 may include silicon nitride (SiN), silicon oxide (SiO), or other similar materials. In certain examples, the second passivation layer 4320 can have a thickness ranging from about 50 nm to about 100 nm.

44A-44C (devices 4401-4403, respectively) are simplified illustrations illustrating method steps for a transfer process for single-crystal acoustic resonator devices and various cross-sectional views of single-crystal acoustic resonator devices according to another example of the present invention. drawings that have been As shown, these figures illustrate method steps for processing second electrode 4210 and top metal 4220 to form processed second electrode 4410 and processed top metal 4420 . This step may follow the formation of second electrode 4210 and top metal 4220 . In one example, processing these two components may include depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar material; and then etching (eg, dry etching or the like) these materials to form a processed second electrode 4410 with an electrode cavity 4412 and a processed top metal 4420 . The processed top metal 4420 remains separated from the processed second electrode 4410 by the removal of portion 4411 . In a particular example, the processed second electrode 4410 is characterized by the addition of an energy confinement structure configured on the processed second electrode 4410 to increase the Q.

45A-45C (devices 4501-4503, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for processing the first electrode 3310 to form the processed first electrode 4510. This step may follow formation of the first electrode 3310 . In one example, processing of these two components may include depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials; and then etching (eg, dry etching or the like) this material to form a processed first electrode 4510 having an electrode cavity, similar to the processed second electrode 4410. . Air cavity 3711 shows the change in cavity shape due to the processed first electrode 4510. In a specific example, the processed first electrode 4510 is characterized by the addition of an energy confinement structure configured on the processed second electrode 4510 to increase Q.

46A-46C (devices 4601-4603, respectively) show method steps for a transfer process using a sacrificial layer for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures show a first electrode 3310 to form a processed first electrode 4510, and a first electrode 3310 to form a processed second electrode 4410/processed top metal 4420. Illustrates method steps for processing the 2 electrode 4210/top metal 4220. These steps may follow formation of each individual electrode as described with respect to FIGS. 44A-44C and 45A-45C. Those skilled in the art will recognize other variations, modifications, and alternatives.

47A-47C-59A-59C illustrate a fabrication method for an acoustic resonator device using a transfer structure with a multilayer mirror structure. In this series of figures described below, “a” figures are simplified figures illustrating a top cross-sectional view of a single crystal resonator device according to various embodiments of the present invention. The "b" figures show simplified diagrams illustrating longitudinal cross-sections of the same devices in the "a" figures. Likewise, the "c" figures show simplified diagrams illustrating transverse cross-sectional views of the same devices in the "a" figures. In some cases, certain features are omitted to emphasize other features and relationships between these features. Those skilled in the art will recognize variations, modifications, and alternatives to the examples shown in this series of figures.

47A-47C (devices 4701-4703, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming a piezoelectric film 4720 to overlie a growth substrate 4710 . In one example, the growth substrate 4710 may include silicon (S), silicon carbide (SiC), or other similar materials. The piezoelectric film 4720 may be an epitaxial film comprising aluminum nitride (AlN), gallium nitride (GaN), or other similar materials. Additionally, such piezoelectric substrates may undergo thickness trimming.

48A-48C (devices 4801-4803, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming the first electrode 4810 to overlie the surface area of the piezoelectric film 4720 . In one example, the first electrode 4810 may include molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials. In a specific example, the first electrode 4810 may undergo a dry etch with a gradient. In one example, the slope may be about 60 degrees.

49A-49C (devices 4901-4903, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming a multilayer mirror or reflector structure. In one example, the multilayer mirror includes at least one pair of layers having a low impedance layer 4910 and a high impedance layer 4920 . In Figures 49A-49C, two pairs of low/high impedance layers are shown (low: 4910 and 4911; high: 4920 and 4921). In one example, the mirror/reflector area may be larger than the resonator area and may surround the resonator area. In certain embodiments, the thickness of each layer is about 1/4 the wavelength of an acoustic wave at the target frequency. The layers can be deposited sequentially and then etched, or each layer can be deposited and etched separately. In another example, the first electrode 4810 may be patterned after the mirror structure is patterned.

50A-50C (devices 5001-5003, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures show a method of forming the support layer 5010 to overlie the mirror structure (layers 4910, 4911, 4920, and 4921), the first electrode 4810, and the piezoelectric film 4720. Illustrate the steps. In one example, the support layer 5010 may include silicon dioxide (SiO ₂ ), silicon nitride (SiN), or other similar materials. In a specific example, this support layer 5010 may be deposited to a thickness of about 2-3 um. As described above, other support layers (eg SiN _x ) may be used.

51A-51C (devices 5101-5103, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for polishing support layer 5010 to form polished support layer 5011 . In one example, the polishing process may include a chemical-mechanical planarization process or the like.

52A-52C (devices 5201-5203, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate turning the device over and physically bonding the overlying support layer 5011 to overlie the bonded substrate 5210 . In one example, the bonding substrate 5210 is a bonding support layer overlying a substrate having silicon (Si), sapphire (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), silicon carbide (SiC), or other similar materials. 5220) (SiO ₂ or similar material). In certain embodiments, bonded support layer 5220 of bonding substrate 5210 is physically bonded to polished support layer 5011 . Additionally, the physical bonding process may include a room temperature bonding process followed by a 300 degree Celsius annealing process.

53A-53C (devices 5301-5303, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate the method steps of removing the growth substrate 4710 or otherwise transferring the piezoelectric film 4720. In one example, the removal process may include a grinding process, a blanket etch process, a film transfer process, an ion implantation transfer process, a laser crack transfer process, or the like, and combinations thereof.

54A-54C (devices 5401-5403, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming an electrode contact via 5410 in the piezoelectric film 4720 to overlie the first electrode 4810 . Via formation processes can include various types of etching processes.

55A-55C (devices 5501-5503, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for forming the second electrode 5510 to overlie the piezoelectric film 4720. In one example, formation of the second electrode 5510 may be accomplished by depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials; and then etching the second electrode 5510 to form the electrode cavity 5511 and to remove the portion 5511 from the second electrode to form the top metal 5520. Additionally, top metal 5520 is physically coupled to first electrode 5520 via electrode contact via 5410 .

56A-56C (devices 5601-5603, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to an example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures form a first contact metal 5610 to overlie a portion of the second electrode 5510 and a portion of the piezoelectric film 4720, and a portion of the top metal 5520. and method steps of forming the second contact metal 5611 to overlie a portion of the piezoelectric film 4720. In one example, the first and second contact metals may include gold (Au), aluminum (Al), copper (Cu), nickel (Ni), aluminum bronze (AlCu), or other similar materials. These figures also illustrate method steps for forming a second passivation layer 5620 to overlie the second electrode 5510 , the top metal 5520 , and the piezoelectric film 4720 . In one example, the second passivation layer 5620 may include silicon nitride (SiN), silicon oxide (SiO), or other similar materials. In a specific example, the second passivation layer 5620 can have a thickness ranging from about 50 nm to about 100 nm.

57A-57C (devices 5701-5703, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for processing second electrode 5510 and top metal 5520 to form processed second electrode 5710 and processed top metal 5720. This step may follow the formation of second electrode 5710 and top metal 5720 . In one example, processing these two components may include depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar material; and then etching (eg, dry etching or the like) these materials to form a processed second electrode 5410 with an electrode cavity 5712 and a processed top metal 5720 . The processed top metal 5720 remains separated from the processed second electrode 5710 by the removal of portion 5711 . In a particular example, this processing provides a greater thickness to the second electrode and top metal while creating electrode cavity 5712 . In a particular example, the processed second electrode 5710 is characterized by the addition of an energy confinement structure configured on the processed second electrode 5710 to increase the Q.

58A-58C (devices 5801-5803, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures illustrate method steps for processing the first electrode 4810 to form the processed first electrode 5810. This step may follow formation of the first electrode 4810 . In one example, processing of these two components may include depositing molybdenum (Mo), ruthenium (Ru), tungsten (W), or other similar materials; and then etching (eg, dry etching or the like) this material to form a processed first electrode 5810 having an electrode cavity, similar to the processed second electrode 5710. . Compared to the two more examples, there are no air cavities. In a particular example, the processed first electrode 5810 is characterized by the addition of an energy confinement structure configured on the processed second electrode 5810 to increase Q.

59A-58C (devices 5901-5903, respectively) show method steps for a transfer process using a multi-layer mirror for single-crystal acoustic resonator devices and various single-crystal acoustic resonator devices according to another example of the present invention. These are simplified drawings illustrating cross-sectional views. As shown, these figures show a first electrode 4810 to form a processed first electrode 5810, and a first electrode to form a processed second electrode 5710/processed top metal 5720. Illustrates method steps for processing the 2 electrode 5510/top metal 5520. These steps may follow formation of each individual electrode as described with respect to FIGS. 57A-57C and 58A-58C. Those skilled in the art will recognize other variations, modifications, and alternatives.

According to various examples, the present invention provides a resonator and RF filter using both textured polycrystalline materials (deposited using PVD methods) and single crystal piezoelectric materials (grown using CVD techniques on a seed substrate). includes devices. A variety of substrates may be used to fabricate acoustic devices, such as silicon substrates of various crystallographic orientations. Additionally, the method may use sapphire substrates, silicon carbide substrates, gallium nitride (GaN) bulk substrates, or aluminum nitride (AlN) bulk substrates. The method may also use GaN templates, AlN templates, and Al _x Ga _1-x N templates, where x varies between 0.0 and 1.0. These substrates and templates may have polar, non-polar, or quasi-polar crystallographic orientations. Additionally, the piezoelectric materials disposed on the substrate may be alloys selected from at least one of the following: AlN, MgHfAlN, GaN, InN, InGaN, AlInN, AlInGaN, ScAlN, ScAlGaN, ScGaN, ScN, BAlN, BAlScN, and BN. can include

In each of the preceding examples, the piezoelectric material may include monocrystalline materials, polycrystalline materials, or a combination thereof, or the like. Piezoelectric materials may also include substantially single-crystal materials, ie essentially single-crystal materials, exhibiting certain polycrystalline qualities. In a specific example, the first, second, third, and fourth piezoelectric materials are each essentially a single-crystal aluminum nitride (AlN)-containing material or an aluminum scandium nitride (AlScN)-containing material, a single-crystal gallium nitride (GaN)-containing material, or gallium aluminum nitride (GaAlN) containing material, magnesium hafnium aluminum nitride (MgHfAlN) material, or the like. In another specific example, these piezoelectric materials are a polycrystalline aluminum nitride (AlN)-containing material or an aluminum scandium nitride (AlScN)-containing material, or a polycrystalline gallium nitride (GaN)-containing material or a gallium aluminum nitride (GaAlN)-containing material, magnesium, respectively. hafnium aluminum nitride (MgHfAlN) material, or the like. In other examples, the piezoelectric materials may include an aluminum gallium nitride (Al _x Ga _1-x N) material or an aluminum scandium nitride (Al _x Sc _1-x N) material characterized by a composition of 0≤X < 1.0. . As discussed above, the thickness of piezoelectric materials can vary and in some cases can be greater than 250 nm.

In each of the preceding examples of transfer processes, energy confinement structures may be formed on the first electrode, the second electrode, or both. In one example, these energy confinement structures are mass loaded regions surrounding the resonator region. The resonator region is a region where the first electrode, the piezoelectric layer, and the second electrode overlap. The larger the mass load in the energy confinement structures, the lower the cut-off frequency of the resonator. The cutoff frequency is a lower limit or an upper limit of a frequency at which acoustic waves can propagate in a direction parallel to the surface of the piezoelectric film. Thus, the cutoff frequency is the resonant frequency at which the wave travels along the thickness direction and thus is determined by the total stack structure of the resonator along the vertical direction. In piezoelectric films (e.g., AlN), acoustic waves with a frequency lower than the cutoff frequency can propagate in a parallel direction along the surface of the film, that is, the acoustic wave is a high-band-cutoff type of dispersion. represents a characteristic. In this case, the mass loaded region surrounding the resonator provides a barrier that prevents acoustic waves from propagating out of the resonator. In doing so, this feature increases the quality factor of the resonator, improves the performance of the resonator, and consequently improves the performance of the filter.

In addition to this, the top monocrystalline piezoelectric layer may be replaced with a polycrystalline piezoelectric film. In these films, the lower portion closer to the interface with the substrate has poor crystalline quality with smaller grain sizes and a wider distribution of piezoelectric polarization orientation than the upper portion of the film closer to the surface. This is due to the polycrystalline growth of the piezoelectric film, i.e., nucleation and the initial film having random crystalline orientations. Considering AlN as a piezoelectric material, the polarization orientation or growth rate along the c-axis is higher than other crystalline orientations which increase the proportion of grains with the c-axis perpendicular to the growth surface as the film grows thicker. For a typical polycrystalline AlN film with a thickness of about 1 um, the upper portion of the film close to the surface has better crystalline quality and better alignment with respect to piezoelectric polarization. By using the thin film transfer process contemplated in the present invention, it is possible to use an upper portion of a polycrystalline film in high frequency BAW resonators with very thin piezoelectric films. This can be done by removing a portion of the piezoelectric layer during the growth substrate removal process. Of course, other variations, modifications, and alternatives may exist.

In one example, the present invention provides a structure and method of fabrication of a monolithic single-chip single crystal device. A monolithic design uses a common single-crystal material layer stack to integrate both passive and active device elements on a single chip. This design can be applied to various device components such as single crystal bulk acoustic resonators, filters, power amplifiers (PAs), switches, low noise amplifiers (LNAs), and the like. These components may be integrated as a mobile radio front-end module (FEM) or other type of FEM. In a specific example, such a monolithic single-chip single crystal device may be a single crystal group III-nitride single chip integrated front end module (SCIFEM). Also, a CMOS based controller chip can be integrated into the package along with the SCIFEM chip to provide a complete communication RF FEM.

60A-60E are simplified circuit diagrams illustrating various monolithic single chip single crystal devices according to various examples of the present invention. 60A shows an antenna switch module 6001 that monolithically incorporates a series of switches 6010. 60B shows a PA duplexer (PAD) 6002 that monolithically integrates a filter 6020 and a PA 6030. 60C shows a switched duplexer bank 6003 that monolithically integrates an antenna switch module 6001, filters 6020, a transmit switch module 6011, and a receive switch module 6012. 60D shows a transmit module 6004 that monolithically integrates an antenna switch module 6001, filters 6020, and PAs 6030. 60E shows a receive diversity module 6005 that monolithically integrates filters 6020, antenna switch module 6001, high band LNA 6041 and low band LNA 6042. These are examples only, and those skilled in the art will recognize other variations, modifications, and alternatives.

61 shows a monolithically integrated system 6100 having an LNA 6140 and PA 6130 coupled to duplexers and filters 6120 coupled to transmit and receive switches 6110. do. These integrated components may include those described in FIGS. 61A-61E. Of course, other variations, modifications, and alternatives may exist.

62A-62E are simplified diagrams illustrating cross-sectional views of various monolithic single chip single crystal devices according to various examples of the present invention. In FIG. 62A, a substrate 6210 serves as the basis for an epitaxial film stack. The substrate may include silicon, silicon carbide, or other similar materials. As shown in device 6201, a first epitaxial layer 6220 is formed overlying the substrate. In a particular example, this first epitaxial layer may include monocrystalline aluminum nitride (AlN) materials and may have a thickness ranging from about 0.01 um to about 10.0 um. Such an epitaxial film may be grown using the processes described above and may be configured for switch/amplifier/filter device applications.

One or more second epitaxial layers 6230 are formed overlying the first epitaxial layer. In one example, these second epitaxial layers may include monocrystalline aluminum gallium nitride (Al _x Ga _1-x N) materials and may be configured for switch/amplifier/filter applications or other passive or active components. can In a particular example, at least one of the second layers may be characterized by a composition of 0 ≤ X < 1.0 and may have a thickness ranging from about 200 nm to about 1200 nm. In another specific example, at least one of the second layers can be characterized by a composition of 0.10 < X < 1.0 and can have a thickness ranging from about 10 nm to about 40 nm. One or more second epitaxial layers may also be grown using the processes described above. The monolithic device 6201 can also include a cap layer 6240 that can include gallium nitride (GaN) materials or the like. The cap layer may have a thickness ranging from about 0.10 nm to about 5.0 nm and may be used to prevent oxidation of one or more second epitaxial layers.

62B shows a cross-sectional view of an example of a single crystal device having an active device with non-recessed contacts. As shown in device 6202 , an active device 6250 is formed overlying cap layer 6240 . If no cap layer is present, the active device will be formed overlying the top layer of one or more second single crystal epitaxial layers 6230 . Such an active device may be a PA, LNA, or switch, or any other active device component.

62C shows a cross-sectional view of an example of a single crystal device having an active device with recessed contacts. As shown in device 6203, an active device 6251 is formed overlying cap layer 6240. Here, the contacts of elements “S” and “D” extend beyond the cap layer and into one or more second single crystalline epitaxial layers 1530 . As mentioned above, such an active device may be a PA, LNA, or switch, or any other active device component.

62D shows a cross-sectional view of an example of a single crystal device having a passive filter device. As shown in device 6204 , filter device 6260 is formed through first single crystal epitaxial layer 6220 with a cavity underlying in substrate 6210 . Other passive elements may also be implemented here.

62E shows a cross-sectional view of an example of a monolithic single chip single crystal device having an active device with non-recessed contacts and a passive filter device. As shown, device 6205 monolithically integrates the devices of FIGS. 62B and 62D with active device element 6250 and filter device 6260 . Of course, other variations, modifications, and alternatives may exist.

In one example, the monolithically integrated components described in FIGS. 60A-60E and 61 may be implemented in an epitaxial stack structure as shown in FIGS. 62A-62E and/or acoustic resonator devices. It may be combined with any of the preceding methods of manufacturing. Compared to conventional embodiments that combine various discrete packaged components into a larger packaged device, the present invention provides multiple unpackaged active and passive single crystal components to monolithically integrate into a single chip package. A method for growing single crystal device layers of This method is possible due to the use of single crystal bulk fabrication processes such as those described above. Using this approach, the resulting device can benefit from reduced size, improved performance, lower integration cost, and faster time to market.

One or more advantages over existing techniques are achieved using the present invention. In particular, the device can be manufactured with lower integration costs by using a smaller PCB area and fewer passive components. The monolithic single chip design of the present invention reduces front end module complexity by eliminating wire bonds and discrete component packaging. Device performance may also be improved due to optimal impedance matching, lower signal loss, and less assembly variability. Depending on the embodiment, one or more of these advantages may be achieved. Of course, other variations, modifications, and alternatives may exist.

According to one example, the present invention provides a method of fabricating a monolithic single chip single crystal device. The method includes providing a substrate having a substrate surface area; forming a first single-crystal epitaxial layer overlying the substrate surface region; processing the first single crystal epitaxial layer to form one or more active or passive device components; forming one or more second single-crystal epitaxial layers to overlie the first single-crystal epitaxial layer; and processing the one or more second single crystal epitaxial layers to form one or more active or passive device components. The first single crystalline epitaxial layer and one or more second single crystalline epitaxial layers may form a monolithic epitaxial stack incorporating multiple circuit functions.

The substrate may be selected from one of the following: silicon substrate, sapphire substrate, silicon carbide substrate, GaN bulk substrate, GaN template, AlN bulk, AlN template, and Al _x Ga _1-x N template. In a specific example, the first single crystalline epitaxial layer includes an aluminum nitride (AlN) material used for RF filter functionality, wherein the first single crystalline epitaxial layer is characterized by a thickness of about 0.01 um to about 10.0 um. In a specific example, at least one of the one or more second single crystalline epitaxial layers comprises a single crystalline aluminum gallium nitride (Al _x Ga _1-x N) material, wherein the second single crystalline epitaxial layer has a composition of 0 ≤ X < 1.0 and characterized by a thickness of about 200 nm to about 1200 nm or about 10 nm to about 40 nm. One or more active or passive device components may include one or more filters, amplifiers, switches, or the like.

In one example, the method may further include forming a cap layer overlying the third epitaxial layer, wherein the cap layer comprises gallium nitride (GaN) materials. In certain instances, the cap layer is characterized by a thickness of about 0.10 nm to about 5.0 nm.

According to one example, the present invention also provides the resulting structure of a monolithic single chip single crystal device. The device includes a substrate having a substrate surface area; a first single-crystal epitaxial layer formed overlying the substrate surface region, the first single-crystal epitaxial layer having one or more active or passive device components; and one or more second single crystalline epitaxial layers formed overlying the first single crystalline epitaxial layer, the one or more second single crystalline epitaxial layers having one or more active or passive device components. include The first single crystalline epitaxial layer and one or more second single crystalline epitaxial layers are formed as a monolithic epitaxial stack incorporating multiple circuit functions.

63 is a flow chart illustrating a method for manufacturing an acoustic resonator device according to an example of the present invention. The following steps are examples only and should not unduly limit the scope of the claims herein. One skilled in the art will recognize many other variations, modifications, and alternatives. For example, the various steps outlined below may be added, removed, modified, rearranged, repeated, and/or overlapped as considered within the scope of the present invention. A typical growth process 6300 can be outlined as follows:

6301. Provides a substrate having the required material properties and crystallographic orientation. A variety of substrates such as silicon, sapphire, silicon carbide, gallium nitride (GaN) or aluminum nitride (AlN) bulk substrates may be used in the method to fabricate the acoustic resonator device. The method may also use GaN templates, AlN templates, and Al _x Ga _1-x N templates, where x varies between 0.0 and 1.0. These substrates and templates may have polar, non-polar, or quasi-polar crystallographic orientations. Those skilled in the art will recognize other variations, modifications, and alternatives;

6302. Place the selected substrate into the processing chamber in a controlled environment;

6303. Heat the substrate to the first desired temperature. At reduced pressure between 5-800 mbar, the substrates are heated to a temperature in the range of 1100° - 1350°C in the presence of purified hydrogen gas as a means to clean the exposed surface of the substrate. The purified hydrogen flow must be in the range of 5-30 slpm (standard liter per minute), and the gas must have a purity greater than 99.9995%;

6304. Cool the substrate to the second desired temperature. After 10-15 minutes at elevated temperature, the substrate surface temperature should decrease by 100-200°C; The temperature offset here is determined by the selection of the substrate material and the initial layer to be grown (highlighted in FIGS. 18A-18C );

6305. Reactants are introduced into the processing chamber. After the temperature has stabilized, group III and group V reactants are introduced into the processing chamber and growth is initiated.

6306. Upon completion of the nucleation layer, the growth chamber pressures, temperatures, and gas phase mixtures may be further adjusted to grow the layer or layers of interest for the acoustic resonator device.

6307. During the film growth process, the strain-state of the material can be adjusted either through modification of growth conditions or by controlled introduction of impurities into the film (as opposed to modification of the electrical properties of the film).

6308. At the end of the growth process, the group III reactants are turned off and the temperature resulting film or films are controllably lowered to room temperature. The rate of thermal change depends on the layer or layers being grown, and in a preferred embodiment, the physical parameters of the substrate containing the films are balanced to be suitable for subsequent processing.

Referring to step 6305, growth of single crystal material is initiated on the substrate via one of several growth methods: direct growth on a nucleation layer, growth on a superlattice nucleation layer, and growth on a staged transition nucleation layer. It can be. Growth of single crystal material may be homoepitaxial, heteroepitaxial, or the like. In the homoepitaxial method, there is minimal lattice mismatch between the substrate and the films, as is the case for native III-N single crystal substrate materials. In heteroepitaxial methods, there is a variable lattice mismatch between the substrate and the film based on in-plane lattice parameters. As described further below, combinations of layers within a nucleation layer may be used to engineer strain within a subsequently formed structure.

Referring to step 6306, a variety of substrates can be used in the method to fabricate an acoustic resonator device. Silicon substrates of various crystallographic orientations may be used. Additionally, the method may use sapphire substrates, silicon carbide substrates, gallium nitride (GaN) bulk substrates, or aluminum nitride (AlN) bulk substrates. The method may also use GaN templates, AlN templates, and Al _x Ga _1-x N templates, where x varies between 0.0 and 1.0. These substrates and templates may have polar, non-polar, or quasi-polar crystallographic orientations. Those skilled in the art will recognize other variations, modifications, and alternatives.

In one example, the method involves controlling the nucleation and material properties of the piezoelectric layer(s). In a particular example, these layers may include single crystal materials constructed with defect densities of less than 1E+11 defects per square centimeter. Single crystal materials may include alloys selected from at least one of the following: AlN, AlGaN, ScAlN, ScGaN, GaN, InN, InGaN, AlInN, AlInGaN, and BN. In various examples, any one or combination of the materials described above may be used for the nucleation layer(s) and/or piezoelectric layer(s) of the device structure.

According to one example, the method involves strain engineering through modification of growth parameters. Even more specifically, the method involves changing the piezoelectric properties of the epitaxial films in the piezoelectric layer through modification of the film growth conditions (such modifications can be measured and compared through the speed of sound of the piezoelectric films). These growth conditions may include nucleation conditions and piezoelectric layer conditions. Nucleation conditions may include temperature, thickness, growth rate, gas phase ratio (V/III), and the like. Piezoelectric layer conditions may include transition conditions from the nucleation layer, growth temperature, layer thickness, growth rate, gaseous phase ratio (V/III), annealing after growth, and the like. Additional details of the method can be found below.

64 is a simplified graph illustrating the results of forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention. This graph highlights the ability to tune the material's acoustic properties for a given aluminum mole fraction. Referring to step 6307 above, this flexibility allows the resulting resonator properties to be tuned for individual applications. As shown, graph 6400 shows a plot of sound velocity (m/s) over aluminum mole fraction (%). Marked region 6420 shows the modulation of sound velocity through strain engineering of the piezoelectric layer at an aluminum mole fraction of 0.4. Here, the data show that the change in sound velocity ranges from about 7,500 m/s to about 9,500 m/s, which is approximately ±1,000 m/s around the initial sound velocity of 8,500 m/s. Thus, modification of the growth parameters provides a large tunable range for the acoustic velocity of the acoustic resonator device. This tunable range will exist for all aluminum mole fractions from 0 to 1.0, a degree of freedom that does not exist in other conventional embodiments of this technology.

The method also includes strain engineering by introducing impurities, or doping, to affect the rate at which sound waves will propagate through the material. Referring to step 6307 above, impurities may be introduced specifically to enhance the rate at which sound waves will propagate through a material. In one example, the impurity species are, but are not limited to, silicon (Si), magnesium (Mg), carbon (C), oxygen (O), erbium (Er), rubidium (Rb), strontium (Sr) ), scandium (Sc), beryllium (Be), molybdenum (Mo), zirconium (Zr), hafnium (Hf), and vanadium (Va). Silicon, magnesium, carbon, and oxygen are common impurities used in the growth process, and their concentrations can be varied for different piezoelectric properties. In certain instances, the impurity concentration ranges from about 1E+10 to about 1E+21 per cubic centimeter. The impurity source used to deliver the impurities can be a source gas, which can be delivered directly after being derived from an organometallic source or through other similar processes.

The method also includes strain engineering by introduction of alloying elements to affect the rate at which sound waves will propagate through the material. Referring to step 6407 above, alloying elements may be introduced specifically to enhance the rate at which sound waves will propagate through the material. In one example, the alloying elements are, but are not limited to, magnesium (Mg), erbium (Er), rubidium (Rb), strontium (Sr), scandium (Sc), titanium (Ti), zirconium (Zr). ), hafnium (Hf), vanadium (Va), niobium (Nb), and tantalum (Ta). In certain embodiments, the concentration of an alloying element (ternary alloys) or elements (in the case of quaternary alloys) ranges from about 0.01% to about 50%. Similarly to the above, the alloying source used to deliver the alloying elements can be a source gas, which can be delivered directly after being derived from an organometallic source or delivered through other similar processes. Those skilled in the art will recognize other variations, modifications, and alternatives.

Methods for introducing impurities can be during film growth (in-situ) or after growth (ex-situ). During film growth, methods for impurity introduction may include bulk doping, delta doping, co-doping, and the like. For bulk doping, a flow process can be used to create a uniform dopant mix. For delta doping, flow processes can be intentionally manipulated for localized regions of higher dopant mixing. For co-doping, any doping methods can be used to simultaneously introduce two or more dopant species during the film growth process. Following film growth, methods for impurity introduction may include ion implantation, chemical treatment, surface modification, diffusion, co-doping, or the like. Those skilled in the art will recognize other variations, modifications, and alternatives.

65A is a simplified diagram illustrating a method for forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention. As shown in device 6501 , a piezoelectric layer 6531 , or film, is grown directly on a nucleation layer 6521 formed overlying a surface region of substrate 6510 . The nucleation layer 6521 can be of the same or different atomic composition as the piezoelectric layer 6531 . Here, the piezoelectric film 6531 may be doped with one or more species during growth (in-situ) or after-growth (ex-situ) as described above.

65B is a simplified diagram illustrating a method for forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention. As shown in device 6502, a piezoelectric layer 6532 or film is grown on a superlattice nucleation layer 6522 composed of layers with alternating compositions and thicknesses. This superlattice layer 6522 is formed overlying the surface area of the substrate 6510. The deformation of the device 6502 can be tuned by the number of alternating layers or cycles in the superlattice layer 6522 or by changing the atomic composition of the constituent layers. Similarly, the piezoelectric film 6532 may be doped with one or more species during growth (in-situ) or post-growth (ex-situ) as described above.

65C is a simplified diagram illustrating a method for forming a piezoelectric layer for an acoustic resonator device according to an example of the present invention. As shown in device 6503, a piezoelectric layer 6533 or film is grown over the graded transition layers 6523. These transition layers 6523 formed to overlie the surface area of the substrate 6510 can be used to adjust the deformation of the device 6503. In one example, the alloy (binary or ternary) content may decrease as a function of growth in the growth direction. These functions can be linear, step-wise, or continuous. Similarly, the piezoelectric film 6533 may be doped with one or more species during growth (in-situ) or post-growth (ex-situ) as described above.

In one example, the present invention provides a method for manufacturing an acoustic resonator device. As described above, the method may include a piezoelectric film growth process, such as direct growth on a nucleation layer, growth on a superlattice nucleation layer, or growth on staged transition nucleation layers. Each process may use nucleation layers comprising materials or alloys having, without limitation, at least one of the following: AlN, AlGaN, GaN, InN, InGaN, AlInN, AlInGaN, and BN. Those skilled in the art will recognize other variations, modifications, and alternatives.

One or more advantages over existing techniques are achieved using the present invention. Specifically, the device can be manufactured in a relatively simple and cost effective manner using conventional materials and/or methods according to one of the techniques common in the art. Using this method, it is possible to create a reliable single crystal based acoustic resonator using multiple methods of 3-dimensional stacking via a wafer level process. These filters or resonators may be implemented within an RF filter device, RF filter system, or the like. Depending on the embodiment, one or more of these advantages may be achieved. Of course, other variations, modifications, and alternatives may exist.

As an example, a packaged device may include any combination of elements described above, as well as those outside of this specification. As used herein, the term “substrate” may refer to a bulk substrate or a substrate such as aluminum, gallium or a ternary compound of aluminum and gallium and nitrogen, combinations, and the like comprising epitaxial regions, or functional regions. It may include overlying growth structures.

66 is a simplified diagram 6600 illustrating a smart phone with a captured image of a user according to one embodiment of the present invention. As shown, a smart phone includes a housing 6610, a display 6620, and an interface device 6630, which may include buttons, a microphone, or a touch screen. Preferably, the phone has a high-resolution camera device that can be used in various modes. One example of a smart phone may be an iPhone from Apple Computer of Cupertino, Calif. Alternatively, the smart phone may be a Galaxy from Samsung or others.

In one example, a smart phone may include the following features (as found on Apple Computer's iPhone 4, but variations may exist), see www.apple.com.

● GSM models: UMTS/HSDPA/HSUPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz)

● CDMA model: CDMA EV-DO Rev. A (800, 1900 MHz)

● 802.11b/g/n Wi-Fi (802.11n 2.4GHz only)

● Bluetooth 2.1 + EDR wireless technology

● Assisted GPS

● Digital compass

● Wi-Fi

● Cellular

● Retina Display

● 3.5-inch (diagonal) widescreen multi-touch display

● 800:1 contrast ratio (typical)

● 500 cd/m2 maximum brightness (typical)

● Anti-fingerprint oleophobic coating on the front and back

● Support for simultaneous display of multiple languages and characters

● 5-megapixel iSight camera

● Video recording, HD (720p) up to 30 frames per second with audio

● VGA-quality photos and videos up to 30 frames per second with front-facing camera

● Tap to focus video or still images

● LED flash

● Photo and video geotagging

● Built-in rechargeable lithium-ion battery

● Charge to computer system or power adapter via USB

● Call time: 3G up to 7 hours, 2G (GSM) up to 14 hours

● Standby time: up to 300 hours

● Internet use: 3G up to 6 hours, Wi-Fi up to 10 hours

● Video playback: up to 10 hours

● Audio playback: up to 40 hours

● Frequency response: 20Hz to 20,000Hz

● Supported audio formats: AAC (8 to 320 Kbps), Protected AAC (from iTunes Store), HE-AAC, MP3 (8 to 320 Kbps), MP3 VBR, Audible (formats 2, 3, 4, Audible Enhanced Audio, AAX and AAX+), Apple Lossless, AIFF and WAV

● User-configurable maximum volume limit

● Up to 720p with Apple Digital AV Adapter or Apple VGA Adapter; 576p and 480p with Apple component AV cables; Supports video output for 576i and 480i with Apple Composite AV Cable (cable sold separately)

● Supported video formats: H.264 video up to 720p in .m4v, .mp4 and .mov file formats, Main Profile Level 3.1 with AAC-LC audio at 30 frames per second, up to 160 Kbps, 48 kHz, stereo audio; MPEG-4 video up to 2.5 Mbps in .m4v, .mp4 and .mov file formats, 640 x 480 pixels, 30 frames per second, simple profile with AAC-LC audio up to 160 Kbps per channel, 48 kHz, stereo audio; Motion JPEG (M-JPEG) in .avi file format up to 35 Mbps, 1280 x 720 pixels, 30 frames per second, audio from ulaw, PCM stereo audio

● 3-axis gyro

● Accelerometer

● Proximity sensor

● Ambient light sensor."

An exemplary electronic device may be a portable electronic device such as a media player, cellular phone, personal data organizer, or the like. Indeed, in these embodiments, a portable electronic device may include a combination of functionalities of these devices. Additionally, an electronic device may enable a user to connect and communicate over the Internet or other networks, such as local or wide area networks. For example, a portable electronic device may enable a user to access the Internet and communicate using e-mail, text messaging, instant messaging, or other forms of electronic communication. As an example, the electronic device may be an iPod or iPhone with a display screen available from Apple Inc.

In certain embodiments, a device may be powered by one or more rechargeable and/or replaceable batteries. Such embodiments may be highly portable, allowing a user to carry the electronic device while traveling, working, exercising, and the like. In this way, and depending on the functionalities provided by the electronic device, the user can listen to music, play games or video, record video or take pictures, make phone calls while moving freely with the device. Send and receive, communicate with others, and control other devices (eg, via remote control and/or Bluetooth functionality). Additionally, the device may be sized so that the device fits relatively easily within a user's hand or pocket. Although particular embodiments of the present invention are described with respect to a portable electronic device, the presently disclosed techniques are applicable to a wide variety of other, less portable, electronic devices and systems configured to render graphics data, such as a desktop computer. It should be noted that there may be

In the presently illustrated embodiment, the exemplary device includes an enclosure or housing 6610, a display, user input structures, and/or input/output connectors. The enclosure may be formed of plastic, metal, composite materials, or other suitable materials, or any combination thereof. The enclosure may protect internal components of the electronic device from physical damage and may also shield internal components from electromagnetic interference (EMI).

The display 6620 may be a liquid crystal display (LCD), a light emitting diode (LED) based display, an organic light emitting diode (OLED) based display, or some other suitable display. According to certain embodiments of the invention, the display may display various other images and user interfaces, such as logos, avatars, photos, album art, and the like. Additionally, in one embodiment, the display may include a touch screen through which a user may interact with the user interface. The display may also include various functional and/or system indicators to provide feedback to the user, such as power status, call status, memory status, or the like. These indicators may be incorporated into a user interface displayed on a display.

In one embodiment, one or more of the user input structures 6630 are configured to control the device, such as by controlling the mode of operation, output level, output type, among other things. For example, user input structures may include a button to turn a device on or off. Additionally, user input structures may enable a user to interact with a user interface on a display. Embodiments of a portable electronic device may include any number of user input structures, including buttons, switches, control pads, scroll wheels, or any other suitable input structures. User input structures can operate in conjunction with a user interface displayed on a device to control the function of the device and/or any interfaces or devices coupled to or used by the device. For example, user input structures may enable a user to return a displayed user interface to a default or home screen or navigate a displayed user interface.

The example device can also include various input and output ports to enable connection of additional devices. For example, the port may be a headphone jack providing connection of headphones. Additionally, the port may have both input/output capabilities to provide connection of a headset (eg, headphone and microphone combination). Embodiments of the present invention may include any number of inputs and/or outputs, such as headphone and headset jacks, universal serial bus (USB) ports, IEEE-1394 ports, AC and/or DC power connectors. may contain ports. Additionally, the device may use the input and output ports to connect to and transmit or receive data to any other device, such as other portable electronic devices, personal computers, printers, or the like. For example, in one example, a device may connect to a personal computer via an IEEE-1394 connection to send and receive data files, such as media files. Additional details of the device can be found in US Pat. No. 8,294,730 assigned to Apple, Inc.

67 is a simplified system diagram 6700 with a smart phone according to one embodiment of the present invention. Server 6701 includes processor 6707, memory 6709, graphics accelerator 6711, accelerometer 6713, communication interface 6715, compass 6717, GPS 6719, display 6712, and input Device 6723 is in electronic communication with a handheld electronic device 6705 having the same functional components. Each device is not limited to the illustrated components. Components may be hardware, software, or a combination of both.

In some examples, instructions that instruct the processor 6707 to execute functions in the electronic imaging application are input to the handheld electronic device 6705 via input device 6723. One potential command could be to create a wireframe of a captured image of a portion of a human user. In this case, the processor 6707 communicates with the server 6701 via the Internet 6703 or the like and instructs the communication interface 6715 to transmit human wireframe or image data. Data transmitted by communication interface 6715 is either processed by processor 6707 immediately after image capture or stored in memory 6709 for later use, or both. Processor 6707 also receives information about attributes of display 6712, for example information from accelerometer 6713 and/or compass heading from compass 6717 or from a GPS chip. External data, such as the GPS location of the device, can be used to calculate the orientation of the device, and the processor then uses the information to determine the orientation to display the image, depending on the example.

In one example, the captured image may be drawn by the processor 6707, by the graphics accelerator 6711, or by a combination of the two. In some embodiments, processor 6707 may be a graphics accelerator. The image may first be drawn to memory 6709, or, if available, memory directly associated with graphics accelerator 6711. The methods described herein may be implemented by the processor 6707, the graphics accelerator 6711, or a combination of the two to generate images and associated wireframes. Once the image or wire frame is drawn to memory, it can be displayed on the display 6721.

68 is a simplified diagram of a smart phone system diagram according to an example of the present invention. System 6800 is an example of hardware, software, and firmware that can be used to implement the above disclosures. System 6800 includes a processor 6801 representing any number of physically and/or logically discrete resources capable of executing software, firmware, and hardware configured to perform the identified computations. Processor 6801 communicates with chipset 6803, which can control inputs to and outputs from processor 6801. In this example, chipset 6803 outputs information to display 6819, reads information from and writes information to non-volatile storage 6821, which can include, for example, magnetic media and solid state media. can be entered. The chipset 6803 can read data from and write data to the RAM 68213. A bridge 6809 for interfacing with various user interface components may be provided for interfacing with the chipset 6803. These user interface components may include a keyboard 6811, a microphone 6813, touch-detection-and-processing circuitry 6815, a pointing device such as a mouse 6817, and the like. In general, inputs to system 6800 may come from any of a variety of sources, machine-generated and/or human-generated.

Chipset 6803 may also interface with one or more data network interfaces 6805, which may have different physical interfaces 6807. These data network interfaces may include interfaces to wired and wireless local area networks, to broadband wireless networks, as well as to personal area networks. Some applications of the methods for creating, displaying, and using GUIs disclosed herein may include receiving data through a physical interface 6807 or a processor that analyzes data stored in memory 6821 or 68213 ( 6801) can be created by the machine itself. In addition, the machine receives inputs from the user via the devices keyboard 6811, microphone 6813, touch device 6814 and pointing device 6817, and interprets these inputs using the processor 6801 to perform browsing You can execute appropriate functions such as functions.

A transmitting module and a receiving module are coupled between the antenna and the data network interfaces. In one example, the transmitting module and receiving module may be separate devices or may be integrated with each other in a single module. Of course, alternatives, modifications, and variations may exist. Additional details of the module can be found throughout this specification and more specifically below.

69 is a simplified diagram of a device 2200 that includes a transmit module and a receive module 6910 according to examples of the invention. In one example, the transmit module and receive module are shown as one block structure. As shown, an RF transmit module is configured on transmit path 6911. An RF receive module is configured on receive path 6912. In one example, antenna 6940 is coupled to RF transmit module 6931 and RF receive module 6932. As shown, an antenna control device 6950 is coupled to receive path 6912 and transmit path 6911 and is configured to select either receive path 6912 or transmit path 6911 . In other examples, antenna control may include various features. These features include signal tracking, filtering, and the like.

In one example, a receive filter 6932 is provided within the RF receive module. In one example, a low noise amplifier device 6960 is coupled to the RF receiving module. The low noise amplifier may be CMOS, GaAs, SiGe process technology, or similar. In one example, transmit filter 6931 is provided within the RF transmit module. The transmit filter includes filter 6930 comprising a single crystal acoustic resonator device. As shown in FIG. 69, filter 6930 includes both transmit and receive filters 6931 and 6932. In one example, power amplifier 6920 is coupled to the RF transmit module and is configured to drive a signal through transmit path 6911 to antenna 6940. In one example, the power amplifier is a CMOS, GaAs, SiGe process technology, or similar.

In one example, band-to-band isolation is such that the difference between pass band and reject band, measured in relative decibels (dBc), is greater than 10 dBc and less than 100 dBc transmit filter characterize In other examples, the difference may have a wider or narrower range. In one example, as the insertion loss characterizing the transmit filter, the insertion loss is less than 3 dB and greater than 0.5 dB. In other examples, the center frequency is configured to define a passband.

In one example, a single crystal acoustic resonator device is included. In one example, a device includes a substrate having a surface area. In one example, the resonator device comprises a first electrode material coupled to a portion of a substrate, and a single crystal capacitor dielectric material having a thickness greater than 0.4 microns and overlying the exposed portion of the surface area and coupled to the first electrode material. have In one example, the monocrystalline capacitor dielectric material is characterized by a dislocation density of less than 10 ¹² defects/cm ² . In one example, the device has a second electrode material overlying the single crystal capacitor dielectric material.

70 is an example of a filter response in an example of the present invention. As shown, response graph 7000 shows attenuation plotted against frequency. Attenuation is measured in decibels (dB), and frequency is measured in hertz. The first region represents the transmit filter response, while the second region represents the receive filter response.

71 is a simplified diagram of a smart phone RF power amplifier module 7100 according to an example of the present invention. In one example, as shown, the RF power amplifier module 7110 is coupled to the processor device as described above in FIGS. 67 and 68 . In one example, RF power amplifier module 7110 is configured in the transmit path and receive path. Additionally, any of the power amplifier modules may include one or more single crystal acoustic wave filters.

In one example, the module has an antenna coupled to the RF power amplifier module 7110. In one example, the module has an antenna control device 7150 configured within the RF power amplifier module 7110. In one example, the control device 7150 is coupled to the receive path and the transmit path and is configured to select either the receive path or the transmit path.

As shown, the module has a plurality of communication bands 7110 configured within the RF power amplifier module. In one example, the plurality of communication bands may be numbered 1 through N, where N is an integer greater than 2 and less than 50, although variations may exist. In one example, each of the communication bands may include a power amplifier. In one example, the power amplifier is a CMOS, GaAs, SiGe process technology, or similar.

In one example, one or more of the communication bands may be configured with a filter device. Filter device 7140 is constructed from a single crystal acoustic resonator device. An example of such a device can be found in US Patent Application Serial No. 14/298,057, assigned to the same applicant and hereby incorporated by reference herein. The module, as shown, may have a single crystal acoustic resonator filter device configured with at least one of a plurality of communication bands. One or more of the communication bands may also be configured with a switching device 7120. Switching device 7120 is coupled to the output impedance matching circuit, as shown. The matching circuit is composed of multiple acoustic wave filters 7140, as shown. Switching device 7120 may also be coupled to transmit (Tx) filter devices 7130 coupled to antenna controller circuit device 7150 . These filter devices 7130 can also be constructed from single crystal resonator devices or any of the acoustic resonator devices discussed above. Paths are controlled by a switching device. In one example, the module performs band-to-band separation between any pair of adjacent communication bands such that the difference between the pass band and the reject band, measured in relative decibels (dBc), is greater than 10 dBc and less than 100 dBc. have In one example, the module has a control device coupled to the RF power amplifier module.

72 is a simplified diagram of a fixed wireless communications infrastructure system according to an example of the present invention. The present invention includes specific architectures for wireless communications infrastructure applications using a variety of single crystal piezoelectric devices. Typical infrastructure systems include controllers, power supplies and/or batteries, cooling infrastructure, transceivers (transmit and/or receive modules), power amplifiers, low-noise amplifiers, switches, antennas, and the like.

As an example, wireless system 7200 includes a controller 7210 coupled to a power source 7221, a signal processing module 7230, and at least one transceiver module 7240. Each of the transceiver modules includes a transmit module 7241 configured on the transmit path and a receive module 7242 configured on the receive path. These pathways may be implemented individually or together. Each of the transmit modules 7241 includes at least a transmit filter having one or more filter devices, while each of the receive modules 7242 includes at least a receive filter. The signal processing module 7230 may be a baseband signal processing module. Additionally, transceiver modules 7240 may include RF transmit and receive modules. Those skilled in the art will recognize other variations, modifications, and alternatives.

Each of these filter (or diplexer) devices includes a single crystal acoustic resonator device. As an example, each device may include a first electrode material, a single crystal material, and a second electrode material. The first electrode material may be bonded to a portion of the substrate. Also, a reflector region may be constructed in the first electrode material. A single crystal material may be formed overlying the exposed areas of the substrate surface area and bonded to the first electrode material. The second electrode material may be formed to overlie the single crystal material. The structure of these resonator devices may also be similar to those described above in FIGS. 1A-12E, 62A-62E, and 65A-65C.

Depending on whether the communication system is a frequency division duplex (FDD) type or a time division duplex (TDD) type, the transmit and receive paths may be separated or shared. In FDD systems, filters are needed to separate transmit and receive and thus separate transmit and receive paths. In TDD systems, since transmission and reception occur on the same channel, there is no need for diplexers to separate transmission and reception. As shown in FIG. 72 , the present invention can have separate channels using filters 7222 (FDD system) or a shared communication channel using diplexers 7222 (TDD system). Those skilled in the art will recognize other variations, modifications, and alternatives.

An antenna section 7251 having an antenna or array of antennas may be coupled to each of the transmit modules 7241 and to each of the receive modules 7242 . An antenna control module 7250 is coupled to each of the receive path, transmit path, and transceiver modules 7240. This antenna control module 7250 is configured to select one of the receive paths or one of the transmit paths in enabling communication path operations. In one example, antenna control module 7250 may be physically configured with a controller and/or signal processing module (as shown). Alternatively, antenna control module 7250 may be physically configured within front-end module 7220, within antenna section 7251, or otherwise closer to antenna section 7251.

In one example, a front-end module 7220 (RF, Bluetooth, or similar) can be coupled to the power supply and conditioning unit 7220 and can be configured between the transceiver 7240 and the antenna 7251. . A switch bank 7221 may be coupled to an antenna 7251, and transmit and receive filters may be configured in a filter module 7222 (which may be a bank of filters). Filter 7222 may be coupled to two switches (or switch banks) 7223 and 7224 configured on the transmit and receive paths, respectively. These switches or switch banks are configured to switch different paths into or out of the signal flow. On the receive path, a switch 7224 may be coupled to a power amplifier 7225 (or bank of PAs) and through it to a transceiver 7240. On the transmit path, a switch 7223 can be coupled to a low noise amplifier 7226 (or bank of LNAs) and through it to a transceiver 7240.

In one example, power supply 7221 and power amplifier module 7222 may be part of a power supply and conditioning unit 7220 coupled to controller 7210, power supply 7220, and transceiver module 7240. A power amplifier module 7260 can be configured on each of the transmit paths and each of the receive paths. This power amplifier module may also include a plurality of communication bands, each of which may have a power amplifier. The filters of transceiver modules 7240 may each be configured for one or more of the communications bands. The number of filters and switches can vary depending on the number of supported bands and other tradeoffs in systems design. Additionally, the power supply and conditioning unit 7220 can be coupled to other sections of the wireless system 7200 or base station (BTS) system (represented by block 2599).

One or more advantages over existing techniques are achieved using the present invention. Wireless infrastructures using the present monocrystalline technology achieve better thermal conductivity, which enables these infrastructures to perform better in high power density applications. The present monocrystalline infrastructures also provide low loss, thus enabling higher out of band rejection (OOBR). With better thermal properties and higher resilience over power, these single crystal infrastructures also achieve higher linearity. Depending on the embodiment, one or more of these advantages may be achieved. Of course, other variations, modifications, and alternatives may exist.

While the above is a complete description of specific embodiments, various modifications, alternative constructions, and equivalents may be used. Accordingly, the above description and examples should not be taken as limiting the scope of the present invention, which is defined by the appended claims.

Claims (20)

As a fixed wireless communication system,
controller;
a power source coupled to the controller;
a baseband signal processing module coupled to the controller;
One or more transceiver modules, each of the transceiver modules comprising:
An RF transmit module coupled to the baseband processing module and configured on a transmit path, the RF transmit module comprising a transmit filter having one or more filter devices, each of the one or more filter devices comprising a single crystal acoustic resonator device. To, the RF transmission module;
the one or more transceiver modules comprising an RF receive module coupled to the baseband signal processing module and configured on a receive path, the RF receive module including a receive filter;
an antenna coupled to each of the RF transmit modules and to each of the RF receive modules;
An antenna control device coupled to each of the receive paths and each of the transmit paths and configured to select one of the receive paths or one of the transmit paths, the antenna control device coupled to the one or more transceiver modules. said antenna control device;
a power amplifier module coupled to the controller, the power supply, and the one or more transceiver modules, the power amplifier module configured on each of the transmit paths and each of the receive paths, the power amplifier module comprising a plurality of communication a power amplifier module comprising bands, each communication band having a power amplifier, wherein the one or more filter devices of each transceiver module are configured in one or more of the plurality of communication bands;
Each single crystal acoustic resonator device of the filter devices comprises:
a substrate having a substrate surface area;
a support layer formed overlying the substrate surface region, the support layer having an air cavity formed therein;
a piezoelectric film formed to overlie the support layer and the substrate, the piezoelectric film having a contact via formed therein;
a bottom electrode configured to underlie a portion of the piezoelectric film, the bottom electrode being configured within the air cavity of the support layer and underlying the contact via of the piezoelectric film;
an upper electrode formed to be placed on a portion of the piezoelectric film;
a top metal formed to overlie a portion of the piezoelectric film, the top metal configured within the contact via of the piezoelectric film;
a first contact metal formed overlying a portion of the piezoelectric film, the first contact metal electrically coupled to the top electrode; and
a second contact metal formed to overlie a portion of the piezoelectric film, the second contact metal electrically coupled to the top metal and to the bottom electrode through the contact via of the piezoelectric film; A system containing metal.
The method of claim 1,
The system further comprises a cooling module coupled to the power supply, the one or more transceiver modules, and the power amplifier module.
The method of claim 1,
wherein the power source comprises a power supply, a battery-based power supply, or a power supply coupled with a battery backup.
The method of claim 1,
The system is configured as a base station, wherein the base station is characterized as macro, micro, nano, pico, or femto, depending on range, capacity, and power capability.
The method of claim 1,
wherein the system is configured as a Wi-Fi access point.
The method of claim 1,
wherein the substrate comprises silicon (S), silicon carbide (SiC), sapphire (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), or other silicon materials.
The method of claim 1,
The piezoelectric film is made of aluminum nitride (AlN), aluminum scandium nitride (AlScN), gallium nitride (GaN), aluminum gallium nitride (AlGaN), Al _x Sc _1-x N or Al _x Ga _1-x N materials (0 ≤ X < 1.0), or a single- or polycrystalline piezoelectric film comprising magnesium hafnium aluminum nitride (MgHfAlN).
The method of claim 1,
The piezoelectric film is made of aluminum nitride (AlN), aluminum scandium nitride (AlScN), gallium nitride (GaN), aluminum gallium nitride (AlGaN), Al _x Sc _1-x N or Al _x Ga _1-x N materials (0 ≤ X < 1.0), or an upper part of a polycrystalline piezoelectric film comprising magnesium hafnium aluminum nitride (MgHfAlN).
The method of claim 1,
The first electrode, the second electrode, and the upper metal include molybdenum (Mo), ruthenium (Ru), tungsten (W), or other conductive materials, and the first and second contact metals are gold (Au ), aluminum (Al), copper (Cu), nickel (Ni), aluminum bronze (AlCu), or other metallic materials.
The method of claim 1,
The substrate comprises a bare and exposed crystalline material, the piezoelectric film is configured to propagate a longitudinal signal at an acoustic velocity greater than 6000 meters per second, the first contact metal and the second contact metal. The system of claim 1 , wherein the contacting metals are configured in a co-planar arrangement.
As a fixed wireless communication system,
controller;
a signal processing module coupled to the controller;
One or more transceiver modules coupled to the controller, each of the transceiver modules comprising:
a transmit module coupled to the signal processing module and configured on a transmit path, the transmit module comprising a transmit filter having one or more filter devices, each of the one or more filter devices comprising a single crystal acoustic resonator device; transmission module;
the one or more transceiver modules comprising a receive module coupled to the signal processing module and configured on a receive path, the receive module comprising a receive filter;
an antenna coupled to each of the transmit modules and to each of the receive modules;
An antenna control device coupled to each of the receive paths and each of the transmit paths and configured to select one of the receive paths or one of the transmit paths, the antenna control device coupled to the one or more transceiver modules. Including the antenna control device, which is,
Each single crystal acoustic resonator device of the filter devices comprises:
a substrate having a substrate surface area;
a support layer formed overlying the substrate surface region, the support layer having an air cavity formed therein;
a piezoelectric film formed to overlie the support layer and the substrate, the piezoelectric film having a contact via formed therein;
a bottom electrode configured to underlie a portion of the piezoelectric film, the bottom electrode being configured within the air cavity of the support layer and underlying the contact via of the piezoelectric film;
an upper electrode formed to be placed on a portion of the piezoelectric film;
a top metal formed to overlie a portion of the piezoelectric film, the top metal configured within the contact via of the piezoelectric film;
a first contact metal formed overlying a portion of the piezoelectric film, the first contact metal electrically coupled to the top electrode; and
a second contact metal formed to overlie a portion of the piezoelectric film, the second contact metal electrically coupled to the top metal and to the bottom electrode through the contact via of the piezoelectric film; A system containing metal.
The method of claim 11,
The system further includes a power amplifier module coupled to the controller, the power supply, and the one or more transceiver modules, the power amplifier module configured on each of the transmit paths and each of the receive paths, wherein the power amplifier module is configured on each of the transmit paths and each of the receive paths; The system of claim 1 , wherein a power amplifier module includes a plurality of communication bands, each communication band having a power amplifier, and wherein the one or more filter devices of each transceiver module are configured in one or more of the plurality of communication bands.
The method of claim 12,
The system,
Any pair of adjacent communication bands within the plurality of communication bands characterizing each of the transmit filters such that the difference between the pass band and the reject band, measured in relative decibels (dBc), is greater than 10 dBc and less than 100 dBc. system further comprising band-to-band separation between
The method of claim 11,
The system further comprises a power source coupled to the controller, the power source comprising a power supply, a battery-based power supply, or a power supply coupled with a battery backup.
As a fixed wireless communication system,
processing device;
As a plurality of transceiver modules, each of the transceiver modules,
an RF transmit module coupled to the processing device and configured on a transmit path, the RF transmit module comprising a transmit filter having one or more filter devices, each of the one or more filter devices comprising a single crystal acoustic resonator device. the RF transmission module;
the one or more transceiver modules comprising an RF receive module coupled to the processing device and configured on a receive path, the RF receive module comprising a receive filter;
a plurality of antennas coupled to the plurality of transceiver modules, each of the plurality of antennas coupled to one of the RF transmit modules and one of the RF receive modules;
A plurality of antenna control devices coupled to the plurality of antennas, each of the plurality of antenna control devices coupled to one of the receive paths and one of the transmit paths, and wherein one of the receive paths or the transmit path the plurality of antenna control devices configured to select one of the paths, wherein the plurality of antenna control devices are also coupled to the plurality of transceiver modules;
A power amplifier module coupled to the processing device and the plurality of transceiver modules, the power amplifier module configured on the transmit path and the receive path of each transceiver module, the power amplifier module configured to transmit a plurality of communication bands. wherein each communication band has a power amplifier, wherein the one or more filter devices of each transceiver module are configured in one or more of the plurality of communication bands;
Any pair of adjacent communication bands within the plurality of communication bands characterizing each of the transmit filters such that the difference between the pass band and the reject band, measured in relative decibels (dBc), is greater than 10 dBc and less than 100 dBc. band-to-band separation between;
an insertion loss characterizing each of the transmission filters, wherein the insertion loss is less than 3 dB and greater than 0.5 dB; and
a center frequency configured to define the passband;
Each single crystal acoustic resonator device of the filter devices comprises:
a substrate having a substrate surface area;
a support layer formed overlying the substrate surface region, the support layer having an air cavity formed therein;
a piezoelectric film formed to overlie the support layer and the substrate, the piezoelectric film having a contact via formed therein;
a bottom electrode configured to underlie a portion of the piezoelectric film, the bottom electrode being configured within the air cavity of the support layer and underlying the contact via of the piezoelectric film;
an upper electrode formed to be placed on a portion of the piezoelectric film;
a top metal formed to overlie a portion of the piezoelectric film, the top metal configured within the contact via of the piezoelectric film;
a first contact metal formed overlying a portion of the piezoelectric film, the first contact metal electrically coupled to the top electrode; and
a second contact metal formed to overlie a portion of the piezoelectric film, the second contact metal electrically coupled to the top metal and to the bottom electrode through the contact via of the piezoelectric film; A system containing metal.
The method of claim 15
wherein the substrate comprises silicon (S), silicon carbide (SiC), sapphire (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), or other silicon materials.
The method of claim 15
The piezoelectric film is made of aluminum nitride (AlN), aluminum scandium nitride (AlScN), gallium nitride (GaN), aluminum gallium nitride (AlGaN), Al _x Sc _1-x N or Al _x Ga _1-x N materials (0 ≤ X < 1.0), or a single- or polycrystalline piezoelectric film comprising magnesium hafnium aluminum nitride (MgHfAlN).
The method of claim 15
The piezoelectric film is made of aluminum nitride (AlN), aluminum scandium nitride (AlScN), gallium nitride (GaN), aluminum gallium nitride (AlGaN), Al _x Sc _1-x N or Al _x Ga _1-x N materials (0 ≤ X < 1.0), or an upper part of a polycrystalline piezoelectric film comprising magnesium hafnium aluminum nitride (MgHfAlN).
The method of claim 15
The first electrode, the second electrode, and the upper metal include molybdenum (Mo), ruthenium (Ru), tungsten (W), or other conductive materials, and the first and second contact metals are gold (Au ), aluminum (Al), copper (Cu), nickel (Ni), aluminum bronze (AlCu), or other metallic materials.
The method of claim 15
The surface region of the substrate is bare and exposed crystalline material, the piezoelectric film is configured to propagate a longitudinal signal at an acoustic speed of 6000 meters/second or more, and the first contact metal and the second contact metal are identical. -A system, consisting of a planar arrangement.

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