Energy confinement in surface acoustic wave device

Abstract

To provide a surface acoustic wave device and a method of manufacturing the same.SOLUTION: A surface acoustic wave (SAW) resonator 100 includes: a crystal substrate 112; a piezoelectric layer 104 which is formed of LiTaO3 or LiNbO3 and disposed on the crystal substrate; and an interdigital transducer (IDT) electrode 102 which is formed on the piezoelectric layer. The surface acoustic wave device further includes a joint layer 123 which is mounted on the piezoelectric film, and a cap layer 124. The cap layer is formed on the joint layer, thereby substantially confining energy of propagation waves below the cap layer.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a joint venture of "Energy Confinement in Acoustic Wave Devices" filed on November 27, 2019. This application claims priority to U.S. Provisional Application No. 62 / 941,683, entitled "Insertion Method for Injecting Into a Microchip," the disclosure of which is incorporated herein by reference. , the entirety of which is expressly incorporated herein by reference.

[0002] The present disclosure relates to acoustic wave devices, such as surface acoustic wave (SAW) devices. [Background technology]

[0003] Surface acoustic wave (SAW) resonators are typically interdigitated resonators mounted on the surface of a piezoelectric layer. The interdigitated transducer (IDT) electrodes are used to connect two interdigitated sets of fingers. In such a configuration, the distance between two adjacent fingers of the same set is suppressed by the IDT electrodes. It is approximately equal to the wavelength λ of the surface acoustic wave being propagated.

[0004] In many applications, the SAW resonator is used to generate radio frequency signals based on the wavelength λ. Such filters can be used as RF filters, which provide a certain number of desired characteristics. can be given. Summary of the Invention

[0005] According to a number of implementations, the present disclosure provides a quartz substrate and a LiTaO3 or LiNbO3 and a piezoelectric film formed and disposed on the quartz substrate. The surface acoustic wave device further includes an interdigital transducer formed on the piezoelectric film. The surface acoustic wave device further includes a laser electrode and a bonding layer mounted on the piezoelectric film. The cap layer is formed on the bonding layer to provide an energy-reducing layer for the propagation wave. The energy is substantially confined below the cap layer.

[0006] In some embodiments, the bonding layer may be formed from SiO2. In some embodiments, the cap layer may be formed from Si.

[0007] In some embodiments, the interdigital transducer electrodes are The cap layer may be formed directly on the upper surface, and the lower surface of the cap layer may be in direct contact with the upper surface of the bonding layer. In some embodiments, the bonding layer seals the interdigital transducer electrodes. In some embodiments, the interdigital transducer The volume above the pole forms a cavity defined by the upper surface of the piezoelectric film and the lower surface of the cap layer. This exposes the interdigital transducer electrodes to the cavity. can be.

[0008] In some embodiments, the cavity is further laterally defined by sidewalls. In some embodiments, the sidewall may be formed by a peripheral portion of the bonding layer. In some embodiments, the sidewalls comprise a wall structure that is at least partially embedded in the bonding layer. It may be formed by a structure.

[0009] In some embodiments, the wall structure includes one or more trenches that are filled with SiN. The one or more trenches may partially or completely surround the cavity. In an embodiment, the one or more trenches may be a single trench that substantially surrounds the cavity. may include:

[0010] In some embodiments, the cap layer comprises one or more layers resulting from the formation of a cavity. An upper opening may be defined.

[0011] In some embodiments, the acoustic wave device further comprises an insulator formed on the piezoelectric film. a first contact pad electrically connected to the terdigital transducer electrode; and In some embodiments, the acoustic wave device may further include a contact pad. , from each of the first contact pad and the second contact pad to the upper surface of the cap layer The conductive vias may extend therethrough.

[0012] In some embodiments, the acoustic wave device is further mounted on the piezoelectric film. - a first reflector and a second reflector disposed on a first side and a second side of the digital transducer electrode; It may include a reflector.

[0013] According to some implementations, the present disclosure relates to a method for fabricating an acoustic wave device. forming or providing a piezoelectric layer formed from LiTaO3 or LiNbO3; and forming interdigital transducer electrodes on the piezoelectric layer. The method further includes mounting a bonding layer on the piezoelectric layer and attaching a cap layer to the bonding layer. and bonding the cap layer and the piezoelectric layer such that the bonding layer is between the cap layer and the piezoelectric layer. The cap layer is configured to allow energy confinement of the propagating wave in the volume below the cap layer. The method further includes thinning the piezoelectric layer to provide a piezoelectric film.

[0014] In some embodiments, the method further includes attaching a quartz substrate to the piezoelectric film. The piezoelectric layer includes a first surface and a second surface, and the interdigital transducer electrodes are disposed on the first surface and the second surface. A bonding layer is formed on a first surface of the piezoelectric layer, and the bonding layer is mounted on the first surface of the piezoelectric layer.

[0015] In some embodiments, thinning the piezoelectric layer provides a new second surface of the piezoelectric film. The second surface of the piezoelectric layer may be attached to the quartz substrate. may include bonding a quartz substrate to the new second surface of the piezoelectric film.

[0016] In some embodiments, the bonding layer is implemented so that the bonding layer is interdigitated. In some embodiments, sealing the digital transducer electrodes may be provided. The bonding layer is mounted on the interdigital transducer electrodes. A cavity is formed between the first surface of the piezoelectric film and the lower surface of the cap layer. and the interdigital transducer electrodes are exposed to the cavity. will be done.

[0017] In some embodiments, the cavity is further laterally defined by sidewalls. In some embodiments, the bonding layer is mounted to further define a periphery of the bonding layer. A sidewall defined by the edge portion is provided.

[0018] In some embodiments, the method further comprises forming a wall structure at least partially within the bonding layer. The method may include embedding the article such that the wall structure forms a sidewall of the cavity.

[0019] In some embodiments, the method further comprises: a first contact associated with the interdigital transducer electrode at a location a cap layer and a contact layer to provide electrical connection to the pad and the second contact pad, respectively; The method may include forming a first conductive via and a second conductive via through the composite layer.

[0020] According to some implementations, the present disclosure provides a method for filtering a signal by using an input node that receives the signal; and an output node providing a filtered signal. The converter further comprises an input node and an output node electrically coupled to generate a filtered signal. The acoustic wave device is mounted between a quartz substrate and a LiTaO a piezoelectric film formed of LiNbO3 or LiNbO3 and disposed on the quartz substrate; and and an interdigital transducer electrode formed on the surface acoustic wave device. The device further includes a bonding layer mounted on the piezoelectric film and a cap layer, the cap layer , by being formed on the bonding layer, the energy of the propagating wave is substantially Confined below the layer.

[0021] In some implementations, the present disclosure is configured to receive multiple components. and a packaging substrate for transmitting and receiving signals mounted on the packaging substrate. and a radio frequency module including radio frequency circuitry configured to support either or both of the The radio frequency module further comprises filtering at least some of the signals. The radio frequency filter includes a quartz substrate and a a piezoelectric film made of LiTaO3 or LiNbO3 and disposed on the quartz substrate; and an interdigital transducer electrode formed on the piezoelectric film. The surface acoustic wave device further includes a bonding layer mounted on the piezoelectric film. and a cap layer, the cap layer being formed on the bonding layer to prevent the conductive layer from being broken. The energy of the carrier wave is substantially confined below the cap layer.

[0022] In some implementations, the present disclosure provides a transceiver, an antenna, and a method for electrically connecting the transceiver. and a wireless system implemented between the antenna. The system includes a filter configured to provide filtering functionality for a wireless system. The filter includes a quartz substrate and a filter formed of LiTaO3 or LiNbO3. A piezoelectric film disposed on a crystal substrate and an interdigital transistor formed on the piezoelectric film. and a transducer electrode. The surface acoustic wave device further comprises: a bonding layer mounted on the piezoelectric film and a cap layer, the cap layer By forming the cap layer on the surface of the substrate, the energy of the propagating wave is substantially confined below the cap layer. To be confined.

[0023] For purposes of summarizing this disclosure, certain aspects, advantages and novel features of the invention have been identified herein. Not all such advantages may be realized with any particular embodiment of the invention. It should be understood that the present invention is not achieved according to the present invention. It is understood that one of the advantages taught herein may be achieved without necessarily achieving other advantages that may be taught or suggested herein. It can be embodied or carried out in a manner that achieves or optimizes an advantage or group of advantages. do. [Brief explanation of the drawings]

[0024] [Figure 1]1 shows an example of a surface acoustic wave (SAW) device implemented as a SAW resonator. [Figure 2] 2 shows an enlarged and isolated plan view of an exemplary interdigital transducer (IDT) electrode implemented in the SAW resonator of FIG. 1. [Figure 3] In some embodiments, a SAW resonator can include a combination of a quartz substrate, a piezoelectric layer, an interdigital transducer (IDT) electrode, a bonding layer mounted on the piezoelectric layer, and a cap layer formed on the bonding layer. [Figure 4] It is shown that in some embodiments, the SAW resonator of FIG. 3 can be configured to include an internal structure that provides electrical connections for, and generally overlies, the IDT electrodes. [Figure 5] A detailed example of the SAW resonator of FIG. 4 is shown. [Figure 6] Another detailed example of the SAW resonator of FIG. 4 is shown. [Figure 7] 5 shows a further detailed example of the SAW resonator of FIG. [Figures 8A-8E] 8A through 8H illustrate an exemplary process that can be utilized to fabricate the exemplary SAW resonator of FIG. [Figure 8F-8H] 8A through 8H illustrate an exemplary process that can be utilized to fabricate the exemplary SAW resonator of FIG. [Figures 9A-9D] 9A-9D illustrate an exemplary process that can be utilized to fabricate the exemplary SAW resonator of FIG. [Figures 10A-10E] 10A through 10H illustrate an exemplary process that can be utilized to fabricate the exemplary SAW resonator of FIG. [Figures 10F-10H] 10A through 10H illustrate an exemplary process that can be utilized to fabricate the exemplary SAW resonator of FIG. [Figure 11] In some embodiments, we demonstrate that multiple units of SAW resonators can be fabricated while in an array format. [Figure 12] It is noted that in some embodiments, a SAW resonator having one or more features described herein can be implemented as part of a packaged device. [Figure 13] It is shown that in some embodiments, the SAW resonator-based packaged device of FIG. 12 can be a packaged filter device. [Figure 14] In some embodiments, a radio frequency (RF) module may include an assembly of one or more RF filters. [Figure 15] 1 illustrates an example of a wireless device having one or more advantageous features described herein. DETAILED DESCRIPTION OF THE INVENTION

[0025] The headings provided herein, if any, are for convenience only and do not necessarily reflect the nature of the invention claimed. It does not affect the scope or meaning of the invention.

[0026] FIG. 1 shows an example of a surface acoustic wave (SAW) device 98 implemented as a SAW resonator. Such a SAW resonator is made of, for example, LiTaO3 (also referred to herein as LT) or LiN The piezoelectric layer 104 may be formed from BO3 (also referred to herein as LN). The layer has a first surface 110 (e.g., the top surface when the SAW resonator 98 is oriented as shown). , and an opposite second surface. The second surface of the piezoelectric layer 104 may be, for example, a quartz substrate 112. Can be attached to.

[0027] The first surface 110 of the piezoelectric layer 104 includes an interdigital transducer (IDT). The electrode 102 may be implemented with one or more reflector assemblies (e.g., 114, 116). FIG. 2 is an enlarged and isolated plan view of the IDT electrode 102 of the SAW resonator 98 of FIG. It will be appreciated that the IDT electrodes 102 of FIGS. 1 and 2 may be more numerous or A reduced number of fingers may be included for two interlocking sets of fingers.

[0028] In the example of FIG. 2, the IDT electrodes 102 are arranged in a first set 120 in an interdigitated manner. The first set 120a includes fingers 122a and the second set 120b includes fingers 122b. between two adjacent fingers of the same set (e.g., adjacent fingers 122a of the first set 120a) The distance is approximately equal to the wavelength λ of the surface acoustic wave associated with the IDT electrode 102. .

[0029] In the example of FIG. 2, various dimensions associated with the fingers are shown. In particular, each finger (12 2a or 122b) are shown to have a lateral width F, and a gap distance G is defined between the two interlocking neighbors. It is shown to be located between the contact fingers (122a and 122b).

[0030] FIG. 3 shows that in some embodiments, the SAW resonator 100 includes a quartz substrate 112 and a pressure The electrode layer 104 (for example, a film made of LiTaO3 or LiNbO3) and the electrode layer 104 are the same as those in the example of FIG. Such a combination may include an interdigital transducer (IDT) electrode 102. Such IDT electrodes may be similar to the example of FIG. 2, with the first electrodes arranged in an interdigitated manner. For purposes of description, the first set of fingers 122a, 122b may include a first set of fingers and a second set of fingers 122a, 122b. The fingers 122a may be electrically connected to the first contact pads 121a, and the second set of Finger 122b may be electrically connected to second contact pad 121b.

[0031] FIG. 3 shows that the SAW resonator 100 further includes a bonding layer 123 ( For example, silicon dioxide (SiO2) may be included. The bonding layer secures the IDT electrodes 102 and the corresponding contact pads 121a, 121b. It may be implemented to be partially or completely encapsulated.

[0032] FIG. 3 shows that in some embodiments, the SAW resonator 100 further comprises a bonding layer 123. It is shown that the cap layer 124 (e.g., silicon (Si)) may be formed thereon. In some embodiments, such a cap layer substantially transfers the energy of the propagating wave to the bonding layer. 123 and / or the piezoelectric layer 104.

[0033] FIG. 4 illustrates that, in some embodiments, the SAW resonator 100 of FIG. 3 may be (e.g., a corresponding Electrical connections for the IDT electrodes 102 (via contact pads 121a, 121b) 137a, 137b. Examples relating to such electrical connections are given here. This is detailed here.

[0034] FIG. 4 also illustrates that, in some embodiments, the SAW resonator 100 of FIG. 3 generally has an ID 1 shows that the T-electrode 102 can be configured to include an internal structure 139 on the T-electrode 102. Several examples related to construction are detailed herein.

[0035] Figure 5 shows a detailed example of the SAW resonator 100 of Figure 4. In the example of Figure 5, the electrical connections (137a, 137b in FIG. 4) are formed so as to penetrate the cap layer 124 and the bonding layer 123. The first conductive via 125a and the second conductive via 125b may be formed. Therefore, the first via 125a is located at or near the top surface 127 of the cap layer 124. , between the first contact pad 121a and the exposed surface 126a (of the first via 125a) Similarly, the second via 125b can provide electrical connection to the top surface of the cap layer 124. 127 or nearby, the second contact pad 121b (the second via 125b) ) electrical connection can be provided to exposed surface 126b.

[0036] In the example of FIG. 5, the internal structure (139 in FIG. 4) is such that the bonding layer 123 is The semiconductor device may be mounted so as to substantially enclose the contact pads 121a, 121b. In this configuration, the cap layer 124 is a solid layer other than the conductive vias 125a and 125b. That's fine.

[0037] An example of a process that can be utilized to fabricate the SAW resonator 100 of FIG. 8A-8H.

[0038] FIG. 6 shows another detailed example of the SAW resonator 100 of FIG. 4. In the example of FIG. 6, the electrical connections (137a, 137b in FIG. 4) are formed so as to penetrate the cap layer 124 and the bonding layer 123. The first conductive via 125a and the second conductive via 125b may be formed. Therefore, the first via 125a is located at or near the top surface 127 of the cap layer 124. , between the first contact pad 121a and the exposed surface 126a (of the first via 125a) Similarly, the second via 125b can provide electrical connection to the top surface of the cap layer 124. 127 or nearby, the second contact pad 121b (the second via 125b) ) electrical connection can be provided to exposed surface 126b.

[0039] In the example of FIG. 6, the internal structure (139 in FIG. 4) is such that the cavity 128 is located between the IDT electrode 10 2. In some embodiments, such a cabinet The T-shaped portion is connected to the upper surface of the piezoelectric layer 104, the lower surface of the cap layer 124, and the peripheral portion of the bonding layer 123. In such a configuration, the cap layer 124 may be defined by One or more openings 12 extending therethrough and sized to allow the formation of a cavity 128. It may include 9.

[0040] An example of a process that can be utilized to fabricate the SAW resonator 100 of FIG. 9A-9D.

[0041] FIG. 7 shows a further example of the SAW resonator 100 of FIG. 4 in more detail. In the example of FIG. 7, Electrical connections (137a, 137b in FIG. 4) pass through the cap layer 124 and the bonding layer 123. The conductive vias 125a and 125b are implemented as first and second conductive vias 125a and 125b. Therefore, the first via 125a is located at or near the top surface 127 of the cap layer 124. 1, the first contact pad 121a and the exposed surface 12 (of the first via 125a) Similarly, a second via 125b can provide electrical connection to the cap layer 12 4 at or near the top surface 127 thereof, the second contact pad 121b and the second via 1 Electrical connection can be made to exposed surface 126b of the substrate 125b.

[0042] In the example of FIG. 7, the internal structure (139 in FIG. 4) is such that the cavity 128 is located between the IDT electrode 10 2. In some embodiments, such a cabinet Tea is defined by the upper surface of the piezoelectric layer 104, the lower surface of the cap layer 124, and the wall structure 131 (e.g., silicon nitride (SiN)) embedded near the peripheral portion of the bonding layer 123. It can be defined by. In such a configuration, the cap layer 124 may include one or more openings 129 that extend through the cap layer 124 and are sized to allow the formation of the cavity 128. In such a configuration, the cap layer 124 may include one or more openings 129 that extend through the cap layer 124 and are sized to allow the formation of the cavity 128. It can be defined by. In such a configuration, the cap layer 124 may include one or more openings 129 that extend through the cap layer 124 and are sized to allow the formation of the cavity 128. .

[0043] An example of a process that can be used to fabricate the SAW resonator 100 of FIG. 7 is described herein with reference to FIGS. 10A to 10H. It is described here with reference to FIGS. 10A to 10H.

[0044] FIGS. 8A to 8H show an exemplary process that can be used to fabricate the exemplary SAW resonator 100 of FIG. 5. In such an exemplary process, it is understood that other materials having similar properties may also be used, even though the use of specific materials is described. It is understood that other materials having similar properties may also be used, even though the use of specific materials is described. It is understood that other materials having similar properties may also be used, even though the use of specific materials is described. .

[0045] FIG. 8A shows that, in some embodiments, the manufacturing process may include a process step in which a relatively thick piezoelectric layer such as the LiTaO3 (LT) layer 104' is formed or provided. It shows that it may include a process step in which a relatively thick piezoelectric layer such as the LiTaO3 (LT) layer 104' is formed or provided. .

[0046] FIG. 8B shows a process step in which the interdigital transducer (IDT) electrodes 102 and the corresponding contact pads 121a, 121b are formed on the surface of the relatively thick LT layer 104' to result in the assembly 160. It shows a process step in which the interdigital transducer (IDT) electrodes 102 and the corresponding contact pads 121a, 121b are formed on the surface of the relatively thick LT layer 104' to result in the assembly 160. .

[0047] FIG. 8C shows a process step in which a bonding layer such as the silicon dioxide (SiO2) bonding layer 123 is formed on the relatively thick LT layer 104' to result in the assembly 161. It shows a process step in which a bonding layer such as the silicon dioxide (SiO2) bonding layer 123 is formed on the relatively thick LT layer 104' to result in the assembly 161. In some embodiments, such a SiO2 bonding layer may be used to bond the IDT electrodes 102 and the contacts. Deposition and polishing are performed to provide a planar layer that seals the tact pads 121a, 121b. The insulating layer may be formed by a chemical mechanical planarization (CMP) process, for example.

[0048] FIG. 8D illustrates a cap layer, such as a silicon (Si) cap layer 124, in the assembly 16. 1 shows the process steps in which the SiO2 bonding layer 123 is bonded to provide SiO2 bonding layer 123.

[0049] FIG. 8E shows the relatively thick LT layer 104' having its thickness reduced to result in assembly 163. 1 shows the process steps for obtaining the LT layer 104. In some embodiments, The thinning process step may be, for example, a polishing process such as a mechanical polishing process, a chemical mechanical process, etc. This can be achieved by a polishing process.

[0050] FIG. 8F shows how a substrate layer such as quartz crystal layer 112 is bonded to LT layer 10 to result in assembly 164. 4. In some embodiments, such a crystal Attachment of layer 112 to LT layer 104 can be achieved by bonding. In the example, the Si cap layer 124 has a surface 127 (e.g., a top surface when oriented as shown) Shown to include.

[0051] FIG. 8G shows the first opening 165a and the second opening 165b to provide the assembly 166. A first contact (e.g., a via) penetrates the Si cap layer 124 and the SiO2 bonding layer 123. The second contact pad 121a and the second contact pad 121b are shaped to expose their corresponding portions. In some embodiments, such openings are formed by, for example, It may be formed by pattern etching or the like.

[0052] FIG. 8H illustrates the use of a first conductive via 12 to provide a SAW resonator 100 similar to the example of FIG. 5a and second conductive via 125b correspond to the first opening 165a and second opening 165b of FIG. 8G. The process steps shown are formed by introducing a conductive material into the In embodiments, such conductive vias may be formed from a conductive material such as a metal. Such conductive material may be inserted into the first and second openings to provide the corresponding electrical connections described herein. The opening can be partially or completely filled. In the example of FIG. 8H, the first conductive via 125a and second conductive via 125b are connected to or through the top surface 127 of the Si cap layer 124. Shown to include nearby corresponding exposed surfaces 126a, 126b.

[0053] 9A-9D illustrate a method for fabricating the exemplary SAW resonator 100 of FIG. 6. In such exemplary processes, the use of specific materials is noted. Although the materials listed are based on a single material, it is understood that other materials having similar properties may also be utilized. .

[0054] FIG. 9A illustrates that in some embodiments, the manufacturing process may include assembly 164 of FIG. may include process steps that can form or provide an assembly 164 similar to Such an assembly can be formed as described herein.

[0055] FIG. 9B shows a process step of thinning the Si cap layer 124 to expose the surface 127′. The thinned Si cap layer 124' is penetrated to provide the assembly 168. One or more openings 129 are formed through the SiO2 bonding layer 123 to expose corresponding portions of the SiO2 bonding layer 123. In some embodiments, such openings can be formed by, for example, pattern etching. In some embodiments, the number, size and Factors such as the size and arrangement of the molecules may be selected to allow for the formation of the cavities described herein. This can be done.

[0056] FIG. 9C shows the cavity 128 formed over the IDT electrode 102 to result in assembly 169. In some embodiments, such a cavity is formed. 1, by etching (e.g., chemically etching) a portion of the SiO2 bonding layer 123 through the opening 129. In the process step of FIG. 9C, (Si The lateral extent of the cavity 128 (through which O2 is removed) can be determined by, for example, openings 129 and / or This can be controlled by the duration of the etching process.

[0057] FIG. 9D illustrates the use of a first conductive via 12 to provide a SAW resonator 100 similar to the example of FIG. 6. 5a and second conductive via 125b are formed. In the embodiment, such conductive vias are first formed in the lateral direction of the cavity 128 (if necessary). The corresponding opening penetrates the Si cap layer 124 and the SiO2 bonding layer 123 (beyond the boundary). The openings are formed to allow the first contact pads 121a and the second contact pads 121b to be attached to the corresponding portions. exposing a portion of the opening (e.g., etching a via pattern), followed by etching the opening It will be understood that such a conductive material may be introduced. The conductive vias may be formed of a conductive material such as a metal, and the conductive material may be The insulating layer may be partially or completely filled to provide the corresponding electrical connections described in .

[0058] 10A-10H illustrate a method for fabricating the exemplary SAW resonator 100 of FIG. In such an exemplary process, the use of specific materials Although a material is described, it is understood that other materials having similar properties may also be utilized. can be.

[0059] FIG. 10A illustrates that, in some embodiments, a manufacturing process forms an assembly 170. In FIG. 10A, the following process steps may be included: The assembly 170 includes a LiTaO3 (LiTaO3) substrate 112 mounted on a substrate such as a quartz substrate 112. one side of a piezoelectric layer, such as layer 104, and an interdigital transducer (IDT) electrode. The electrode 102 and the corresponding contact pads 121a, 121b are mounted on the other side of the LT layer 104. and a bonding layer, such as a silicon dioxide (SiO2) bonding layer 123, applied to the substrate. In some embodiments, such an assembly may include, for example, a silicon (Si) cap layer 12 4 from the assembly 164 described with reference to FIG. 8F and FIG. 9A. It can be formed by removing (eg, by etching).

[0060] FIG. 10B illustrates the process by which one or more openings 171 are formed to result in assembly 172. In some embodiments, such openings are ID steps when viewed from above. The T-electrode 102 may be partially or completely surrounded by one or more trenches. The trench may be implemented to surround the IDT electrode 102. In this case, such a trench can be formed by, for example, pattern etching. .

[0061] FIG. 10C shows the assembly 172 with the opening 171 inserted therein to provide the assembly 173. It can be filled with a material such as silicon dioxide (SiN) to provide a SiN wall structure 131. In some embodiments, such SiN wall structures include: It can partially or completely surround the IDT electrode 102 when viewed from above. , when there is one trench 171 surrounding the IDT electrode 102, the resulting Si The N-wall structure 131 may also surround the IDT electrode 102. 1, the wall structure 131 is formed by depositing, for example, SiN in the trench 171; A subsequent polishing process removes the bonding layer 123 and the upper portion of the SiN wall structure 131. and providing a desired surface comprising:

[0062] FIG. 10D shows the removal of the silicon (Si) cap layer 124 to result in assembly 174. 1 illustrates process steps in which such a cap layer is formed. A thick Si layer is bonded to a SiO2 bonding layer 123 and thinned to form a Si capacitor with a top surface 127. In this configuration, the Si cap layer 124 is formed by SiO2 The bonding layer 123 and the upper portion of the SiN wall structure 131 may be covered.

[0063] FIG. 10E shows one or more electrodes drilled through the Si cap layer 124 to result in assembly 175. An upper opening 129 can be formed to expose a corresponding portion of the SiO2 bonding layer 123. In some embodiments, such openings can be formed by, for example, In some embodiments, such openings may be formed by turn etching or the like. Factors such as the number, size and arrangement of the electrodes are determined to allow for the formation of the cavities described herein. can be selected.

[0064] FIG. 10F shows the cavity 12 above the IDT electrode 102 to result in assembly 176. 8. In some embodiments, such a cavity The adhesive layer 124 is formed by etching (e.g., chemically etching) a portion of the SiO2 adhesive layer 123 through the opening 129. In the process step of FIG. 10F, S The SiN wall structure 131 is a thin film that is etched horizontally when the SiN wall structure is not present. The lateral direction of the cavity 128 may be increased even if the cavity 128 is expanded in the lateral direction. The range of the

[0065] FIG. 10G shows the first opening 177a and the second opening 177b to provide assembly 178. b (e.g., vias) penetrate the Si cap layer 124 and the SiO2 bonding layer 124 to form the first contact The contact pads 121a and the corresponding portions of the second contact pads 121b are exposed. In some embodiments, such openings are formed, e.g., For example, it may be formed by pattern etching or the like.

[0066] FIG. 10H illustrates the process of removing first conductive via 1 to provide a SAW resonator 100 similar to the example of FIG. 10G. b shows a process step formed by introducing a conductive material into In some embodiments, such conductive vias may be formed from a conductive material such as a metal. Such conductive material may be inserted into the first and second openings to provide the corresponding electrical connections described herein. The opening can be partially or completely filled. In the example of FIG. 10H, the first conductive via The first conductive via 125a and the second conductive via 125b are connected to or on the top surface 127 of the Si cap layer 124. 126a, 126b.

[0067] FIG. 11 illustrates a method for connecting multiple units of SAW resonators in an array format in some embodiments. For example, the wafer 200 can be fabricated while the unit 100 of one array is in a ', and such units remain coupled together through a certain number of process steps. For example, in some embodiments, FIGS. 8A-8H, 9A-9D, 10A to 10H, all of the process steps are performed for such units. This can be accomplished while the array of devices is bonded together in wafer form.

[0068] Upon completion of the above-described process steps in wafer form, the array of units 100' The SAW resonator 100 can be singulated to provide a large number of SAW resonators 100. One of the resonators 100 is depicted. In the example of FIG. 11, the individual SAW resonators 100 are: 5. It will be understood that the singulated SAW resonator 1 of FIG. 00 may also represent other configurations, including the examples of FIGS.

[0069] FIG. 12 illustrates, in some embodiments, an SA having one or more features described herein. It is shown that the W resonator 100 can be implemented as part of a packaged device 300. The packaged device receives and accommodates one or more components, including the SAW resonator 100. In some embodiments, the packaging substrate 302 may include a packaging substrate 302 configured to support the In this regard, the package device 300 may be configured to provide radio frequency (RF) functionality. This can be done.

[0070] FIG. 13 illustrates, in some embodiments, the SAW resonator-based package device of FIG. 3 shows that the device 300 can be a packaged filter device 300. The device may be configured to provide a filtering function, such as an RF filtering function. 1. The SAW resonator 100 includes a packaging substrate 302 suitable for receiving and supporting the SAW resonator 100. obtain.

[0071] FIG. 14 illustrates that in some embodiments, a radio frequency (RF) module 400 4 shows that the RF filter assembly 406 may include the above. W resonator-based filter 100, packaged filter 300, or any combination thereof In some embodiments, the RF module 400 of FIG. For example, an RF integrated circuit (RFIC) 404 and an antenna switch module (ASM) ) 408. Such modules may also include, for example, In some embodiments, the above-mentioned Some or all of the components are mounted by a packaging substrate 402 It may be supported.

[0072] In some implementations, a device and / or The circuitry may be included in an RF device, such as a wireless device. The circuitry may be implemented directly in the wireless device, in a modular format as described herein, or in a In some embodiments, such wireless devices may be implemented in any combination. Examples of such devices include mobile phones, smartphones, and handheld devices with or without telephony capabilities. This may include wireless devices, wireless tablets, etc.

[0073] FIG. 15 illustrates an example of a wireless device 500 having one or more advantageous features described herein. In the context of a module having one or more features described herein, such module The module is generally depicted by a dashed box 400, e.g., a front-end module (FE In such an example, one or more SAWs described herein may be implemented as a The filter may be included in an assembly of filters, such as a duplexer 526. .

[0074] Referring to FIG. 15, a plurality of power amplifiers (PAs) 520 transmit and receive corresponding RF signals. The transceiver 510 may receive an RF signal to be amplified and transmitted. The transceiver may be constructed and operated in a known manner to transmit and process received signals. 510 is shown interacting with the baseband subsystem 408. The service system 408 transmits appropriate data and / or voice signals to the transceiver 51. The transceiver 510 is also configured to provide conversion between the RF signal and the RF signal appropriate for the oscilloscope. a power management component configured to manage power for operation of the wireless device 500; Such power management may also be in communication with the baseband subsystem 506. 08 and the operation of module 400 can also be controlled.

[0075] The baseband subsystem 508 processes the audio and video signals provided to and received from the user. and / or connected to a user interface 502 to facilitate various inputs and outputs of data. The baseband subsystem 508 also facilitates the operation of the wireless device. Stores data and / or instructions to perform a task and / or store information for the user The processor 502 is also connected to a memory 504 configured to:

[0076] In the example wireless device 500, the outputs of the multiple PAs 520 are connected to corresponding duplexers. 526. Such amplified and filtered signal is then transmitted to For transmission purposes, the signal is routed to an antenna 516 via an antenna switch 514. In some embodiments, a duplexer 526 allows a common antenna (e.g., 516) In FIG. 15, the transmission and reception operations are performed simultaneously using the The signal is routed to an "Rx" path (not shown), which may include, for example, a low noise amplifier (LNA). It is shown to be.

[0077] Unless the context clearly requires otherwise, throughout the specification and claims In this regard, the words "including," "comprises," and the like are used in an inclusive sense as opposed to an exclusive or exhaustive sense. In general, the term "including but not limited to" should be interpreted as meaning "including but not limited to" The term "coupled" as used herein means that two or more elements are directly connected or joined together through one or more interconnections. It is noted that the present application may be either connected via an inter-connection element. When used herein, the terms "herein," "above," "below," and words of similar import shall mean the Reference is made to the application as a whole and not to any particular portion of this application. Where permitted, terms in the above detailed description using singular or plural number refer to the respective "Or" and "if" refer to a list of two or more items. The term "or" means any of the items in a list, Covers all of the items in the list, and any combination of the items in the list. .

[0078] The above description of embodiments of the present invention is not intended to be exhaustive or to limit the scope of the present invention. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. While the embodiments and examples are described above for illustrative purposes, those skilled in the art will recognize that the present invention Various equivalent modifications are possible within the scope. For example, if the processes or blocks are arranged in a given order, While presented in the figures, alternative embodiments may perform or have routines with steps in a different order. can use a system with blocks, some processes or blocks These processes or blocks may be deleted, moved, added, subdivided, combined and / or modified. Each of the blocks may be implemented in a variety of different ways. While these processes or blocks may be shown as being performed in a sequence, Alternatively, they may be performed in parallel or at different times.

[0079] The teachings of the present invention provided herein may be applied to other systems, not necessarily the systems described above. The elements and operations of the various embodiments described above may be applied to further implementations. They may be combined to give form.

[0080] While certain embodiments of the present invention have been described, these embodiments are presented by way of example only. and are not intended to limit the scope of the present disclosure. Indeed, The novel methods and systems may be embodied in a variety of other forms and may further be incorporated into the methods and systems described herein. Various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of this disclosure. The accompanying claims and their equivalents are intended to obscure the scope and spirit of this disclosure. It is intended to cover any form or modification thereof that would fit within the scope of the present invention.

Claims

1. A surface acoustic wave device, A quartz substrate; LiTaO ３ or LiNbO ３ a piezoelectric film formed from the above and disposed on the quartz crystal substrate; an interdigital transducer electrode formed on the piezoelectric film; a bonding layer mounted on the piezoelectric film; Cap layer and Including, The cap layer is formed on the bonding layer to substantially absorb the energy of the propagating wave. effectively confining the surface acoustic wave device beneath the cap layer.

2. The bonding layer is made of SiO ２ The acoustic wave device of claim 1 formed from

3. The acoustic wave device of claim 1 , wherein the cap layer is formed from Si.

4. the interdigital transducer electrodes are formed directly on the top surface of the piezoelectric film; The acoustic wave device of claim 1 , wherein the lower surface of the cap layer directly contacts the upper surface of the bonding layer.

5. The elastic substrate of claim 4, wherein the bonding layer seals the interdigital transducer electrodes. Wave device.

6. The volume above the interdigital transducer electrode i is in contact with the upper surface of the piezoelectric film. a cavity defined by a lower surface of the cap layer; 5. The method of claim 4, wherein the interdigital transducer electrodes are exposed to the cavity. Acoustic wave devices

7. 7. The acoustic wave device of claim 6, wherein the cavity is further laterally defined by sidewalls. 。

8. The acoustic wave device of claim 7 , wherein the sidewall is formed by a peripheral portion of the bonding layer.

9. The sidewall is formed by a wall structure at least partially embedded in the bonding layer. The acoustic wave device of claim 7 .

10. the wall structure includes one or more trenches filled with SiN; 10. The elastic member of claim 9, wherein the one or more trenches partially or completely surround the cavity. Wave device.

11. the one or more trenches include a single trench that substantially surrounds the cavity. The acoustic wave device of claim 9.

12. the cap layer defines one or more openings resulting from the formation of the cavities. The acoustic wave device of claim 6.

13. A piezoelectric film is formed on the piezoelectric film and electrically connected to the interdigital transducer electrodes.

10. The elastic member of claim 1, further comprising a first contact pad and a second contact pad connected thereto. Wave device.

14. The first contact pad and the second contact pad are connected to the cap layer. The acoustic wave device of claim 13 , further comprising a conductive via extending to the surface.

15. The first and second sides of the interdigital transducer electrodes are mounted on the piezoelectric film. The acoustic wave device of claim 1 , further comprising a first reflector and a second reflector disposed on either side of the acoustic wave device.

16. 1. A method of fabricating an acoustic wave device, comprising: LiTaO ３ or LiNbO ３ forming or providing a piezoelectric layer formed from forming interdigital transducer electrodes on the piezoelectric layer; mounting a bonding layer on the piezoelectric layer; bonding a cap layer to the bonding layer; thinning the piezoelectric layer to provide a piezoelectric film; Including, the bonding layer is between the cap layer and the piezoelectric layer; The cap layer allows for energy confinement of the propagating wave in the volume below the cap layer. The method is configured to:

17. The method of claim 16 further comprising attaching a quartz substrate to the piezoelectric film.

18. the piezoelectric layer has a first surface and a second surface; the interdigital transducer electrodes are formed on the first surface of the piezoelectric layer; The method of claim 17 , wherein the bonding layer is attached to the first surface of the piezoelectric layer.

19. Thinning the piezoelectric layer creates a new layer of the piezoelectric film on the side of the second surface of the piezoelectric layer.

20. The method of claim 18, wherein the method is performed to provide a second surface.

20. Attaching the quartz substrate to the piezoelectric film involves attaching the water to the new second surface of the piezoelectric film.

20. The method of claim 19, further comprising bonding a crystalline substrate.

21. Mounting the bonding layer may be performed by mounting the bonding layer on the interdigital transducer.

20. The method of claim 18, resulting in sealing the pole.

22. Mounting the bonding layer includes providing a cap over the interdigital transducer electrodes. Bringing cavity, the cavity is defined by the first surface of the piezoelectric film and a lower surface of the cap layer; 10. The method of claim 1, wherein the interdigital transducer electrodes are exposed to the cavity. Method 8.

23. 23. The method of claim 22, wherein the cavity is further laterally defined by sidewalls.

24. Mounting the bonding layer further comprises: the sidewall being formed by a peripheral portion of the bonding layer.

24. The method of claim 23, wherein

25. A wall structure is formed at least partially within the bonding layer, and the wall structure is formed in the cavity.

24. The method of claim 23, further comprising recessing to form sidewalls.

26. The interdigital transistors are disposed at or near the top surface of the cap layer. The first and second contact pads associated with the transducer electrodes a first conductive via extending through the cap layer and the bonding layer to provide electrical connection to each of the first conductive vias; 20. The method of claim 18, further comprising forming a first conductive via and a second conductive via.

27. 1. A radio frequency filter comprising: an input node for receiving a signal; an output node providing the filtered signal; electrically coupled to the input node and the output node to generate the filtered signal. and an acoustic wave device mounted between the Including, The acoustic wave device includes a quartz substrate and a LiTaO ３ or LiNbO ３ and A piezoelectric film disposed on a quartz substrate and an interdigital transducer formed on the piezoelectric film. a transducer electrode; The surface acoustic wave device further includes a bonding layer mounted on the piezoelectric film, a cap layer, and Including, The cap layer is formed on the bonding layer to substantially absorb the energy of the propagating wave. effectively confining the surface acoustic wave device beneath the cap layer.

28. 1. A radio frequency module, comprising: a package substrate configured to receive a plurality of components; A semiconductor integrated circuit (IC) mounted on the package substrate and supporting one or both of transmission and reception of a plurality of signals. a radio frequency circuit configured to a radio frequency filter configured to filter at least some of the signals. and Including, The radio frequency filter comprises a quartz substrate and a LiTaO ３ or LiNbO ３ formed from A piezoelectric film disposed on the quartz substrate, and an interdigital a surface acoustic wave device having a transducer electrode; The surface acoustic wave device further includes a bonding layer mounted on the piezoelectric film, a cap layer, and Including, The cap layer is formed on the bonding layer to substantially absorb the energy of the propagating wave. a radio frequency module substantially enclosed beneath said cap layer.

29. 1. A wireless device, comprising: A transmitter / receiver; The antenna and a wireless system implemented to be electrically present between the transceiver and the antenna; Including, The wireless system is configured to provide a filtering function for the wireless system. Contains filters that can be used The filter is made of a quartz substrate and LiTaO ３ or LiNbO ３ The quartz crystal base is formed from A piezoelectric film disposed on the plate, and an interdigital transformer formed on the piezoelectric film. a transducer electrode; The surface acoustic wave device further includes a bonding layer mounted on the piezoelectric film, a cap layer, and Including, The cap layer is formed on the bonding layer to substantially absorb the energy of the propagating wave. effectively encapsulating a wireless device beneath said cap layer.

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