TW202221950A - Electrode-defined unsuspended acoustic resonator - Google Patents

Abstract

A bulk acoustic resonator operable in a bulk acoustic mode includes a resonator body mounted to a separate carrier that is not part of the resonator body. The resonator body includes a piezoelectric layer, a device layer, and a top conductive layer on the piezoelectric layer opposite the device layer. The piezoelectric layer is a single crystal of LiNbO3 cut at an angle of 130 DEG ± 30 DEG. A surface of the device layer opposite the piezoelectric layer is for mounting the resonator body to the carrier.

Description

Electrodes define unsuspended acoustic resonators

The present invention relates to a BAW resonator, in particular to a BAW resonator, which has a resonator body, and optionally has one or more connecting structures, the aforementioned connecting structures can be used to supply electrical signals to one or more Conductive layers of a plurality of resonators.

Wireless communication has progressed from the "1G" system in the 1980s to the "2G" system in the 1990s, to the "3G" system in the 2000s, to the "4G" system that has been standardized in 2012. In existing wireless communications, surface-acoustic-wave (SAW) filters or bulk-acoustic-wave (BAW) filters are used to filter RF signals.

Film-bulk-acoustic-resonators (FBAR) and solid-mounted-resonators (SMR) are two types of BAW filters, which are piezoelectrically driven micro-electromechanical systems (micro-electromechanical systems). -mechanical-system; MEMS) devices, which can resonate today's 4G wireless communications at relatively high frequencies and relatively low insertion loss compared to SAW filter devices. These BAW acoustic resonators include a piezoelectric stack having, for example, a film of piezoelectric material sandwiched between an upper electrode film and a lower electrode film. The resonant frequencies of these piezoelectric stacks are thickness-based or depend on the thickness of the films of the piezoelectric stacks. The resonance frequency increases as the thickness of the thin film of the piezoelectric stack decreases. The film thickness of the resonator is critical and must be precisely controlled to obtain the desired resonant frequency. It is difficult and time consuming to modify different areas of the piezoelectric stack to achieve a uniformly high level of thickness in order to achieve a target or specific RF frequency within a reasonable yield of the FBAR and SMR production process.

The 5G wireless communication system under development will eventually replace the earlier, lower-performance communication systems whose RF frequencies were between a few hundred MHz and 1.8 GHz. 5G systems will operate at higher RF frequencies such as: 3-6 GHz (below 6 GHz) or up to 100 GHz.

Due to the increase in frequency, it is necessary to increase the resonant frequency by reducing the film thickness of FBAR and SMR-related RF filters used in 5G applications, which is one of the challenges faced by BAW acoustic resonators in the state of the art. The reduction in the thickness of the piezoelectric film represents a reduction in the distance between the upper and lower electrodes of the piezoelectric stack, resulting in an increase in capacitance. The rise in capacitance results in higher feedthrough of the RF signal and reduces the signal to noise ratio, which is undesirable. The ideal piezoelectric coupling efficiency of the piezoelectric stack (upper electrode, lower electrode, and piezoelectric layer between the upper and lower electrodes) can come from an ideal combination of the thickness of the piezoelectric layer, the thickness of the upper electrode, the thickness of the lower electrode and the alignment and orientation of the piezoelectric crystals. In order to achieve the high RF frequency operation required for 5G communication, reducing the thickness of the piezoelectric film may not achieve optimal piezoelectric coupling efficiency, resulting in higher insertion loss and higher kinetic impedance. The thickness of the electrodes, whether the upper electrode, the lower electrode or both, must be reduced. The reduction in electrode thickness leads to an increase in resistivity, which will lead to another undesired limitation, higher insertion loss.

Also, the product of frequency and the quality factor (or Q value) of the FBAR and SMR devices are generally unchanged, which means that an increase in the resonant frequency will lower the Q value. The decrease in the Q value is not expected, especially because the current state of the art for FBAR and the Q of SMR are about to approach the theoretical limit frequency of 2.45 GHz or lower. Therefore, doubling the frequency results in a lower Q value, making it difficult to manufacture RF devices such as RF filters, RF resonators, RF switches, and RF oscillators.

In view of this, the present invention provides a resonator body that can operate using a bulk acoustic wave mode, ideally a lateral resonance mode. The bottom of the resonator body can be mounted or coupled to a mounting substrate or carrier, and the resonator body can be used as an RF filter, an RF resonator, an RF switch, an RF oscillator, and the like.

The present invention also provides a bulk acoustic wave resonator, which includes a resonator body and one or more connecting structures, which can transmit electrical information to one or more conductive layers of the resonator body. In an ideal and non-limiting embodiment or example, the one or more connecting structures can be integrally formed and/or formed of the same layer of material as the resonator body, so the BAW resonator can be a single object. The bottom of the single-object BAW resonator can be mounted or coupled to a mounting substrate or carrier, and the resonator body can be used as an RF filter, RF resonator, RF switch, and RF oscillator.

The BAW resonator of the present invention is characterized in that it comprises: a resonator body, comprising: a piezoelectric layer; a device layer; and an upper conductive layer, which is located above the piezoelectric layer and between the piezoelectric layer The other side is the device layer; wherein the entire surface of the device layer opposite to the piezoelectric layer is substantially used to mount the resonator body on the carrier and separate the resonator body.

For the purposes of the following detailed description, it is to be understood that the present invention may assume various alternative situations and sequences of steps unless expressly indicated to the contrary. It should also be understood that the specific devices and methods described in the following description are merely exemplary implementations, examples, or aspects of the present invention. Also, except in any operational examples or otherwise specifically stated, the description and the scope of the patent application are in ideal and non-limiting embodiments, examples, and levels, and in all cases, the quantities of ingredients mentioned should be understood as the word "about" . Accordingly, unless expressly indicated to the contrary, the numerical parameters set forth in the following specification and claims are approximations that can vary depending upon the desired properties to be obtained by the present invention. Accordingly, each numerical parameter should at least be construed in light of the number of reported significant digits and by ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

Also, it is to be understood that any numerical range recited herein is intended to include all sub-ranges included therein. For example: a range of "1 to 10" is intended to include (and include) all subranges between the recited minimum value of 1 and the recited maximum value of 10. That is, the minimum value is equal to or greater than 1 and the maximum value is equal to or less than 10.

It should also be understood that the specific devices and steps described in the drawings and the following description are merely exemplary embodiments, examples or aspects of the present invention. Accordingly, exemplary embodiments, instances or aspects of the invention are not limited to specific dimensions or other relevant physical characteristics. Certain desirable and non-limiting embodiments, examples, or aspects of the present invention will be described by means of the like element numbers corresponding to the same or functionally equivalent elements in the drawings.

In the present invention, unless specifically stated otherwise, the use of the singular can include the plural and the plural surrounds the singular. Also, in the present invention, unless otherwise specified, the use of "or" means "and/or", even though "and/or" may be used in a specific situation. Further, in the present invention, the use of "a" means "at least one" unless otherwise specified.

For the purposes of the following description, the words "end", "top", "bottom", "right", "left", "vertical", "horizontal", "top", "bottom", "horizontal", "vertical" and its derivatives should be related to the examples in the figure. It should be understood, however, that the examples may assume various alternative situations and order of steps unless specifically stated otherwise. It should be noted that the drawings and specific examples described in this specification are merely illustrative examples or aspects of the present invention. Therefore, the illustrative examples or aspects disclosed herein should not be limited thereto.

As shown in FIG. 1, in one ideal and non-limiting implementation or example, an unsuspended bulk acoustic resonator (UBAR) 2 can operate in a bulk acoustic wave mode and includes a resonator body in accordance with the principles of the present invention 4. It may comprise stacked layers from top to bottom, the stacked layers comprising an upper conductive layer 6, a piezoelectric layer 8, an optional lower conductive layer 10 and a device layer 12. In the example of the UBAR 2 shown in FIG. 1 , the bottom of the conductive layer 12 can be mounted, for example, directly on the mounting substrate or carrier 14 .

Referring to FIG. 2 and continuing with FIG. 1, in an ideal and non-limiting implementation or example, according to the principles of the present invention, another UBAR2 example may be similar to the UBAR2 shown in FIG. 1, with the difference being the resonance of FIG. 2 The device body 4 may include an optional substrate 16 between the device layer 12 and the carrier 14 . In one example, the bottom of conductive layer 12 may be mounted, eg, directly on top of substrate 16 , and the bottom of substrate 16 may be mounted, eg, directly on carrier 14 .

Referring to FIG. 3 and continuing with FIGS. 1 and 2, in an ideal and non-limiting implementation or example, according to the principles of the present invention, another example of UBAR2 may be similar to the UBAR2 shown in FIG. 2, with the difference of FIG. 3 The resonator body 4 may include an optional second substrate 16-1 between the device layer 12 and the piezoelectric layer 8 or the optional lower conductive layer 10, and/or between the second substrate 16-1 and the piezoelectric layer 10. A second device layer 12-1 is included between the electrical layer 8 or the optional lower conductive layer 10. In an ideal and non-limiting implementation or example, the resonator body 4 of FIG. 3 may further include one or more additional device layers 12 (not specifically shown) and/or one or more additional substrates 16 (not specifically shown) is better. Another example resonator body 4 has several device layers 12 and substrate 16, and may include an exemplary sequence, from piezoelectric layer 8 or optional lower conductive layer 10 to carrier 14, as: first device layer , the first substrate, the second device layer, the second substrate; the third device layer, the third substrate, etc. are so connected. In an ideal and non-limiting embodiment or example, the resonator body 4 may include a plurality of device layers 12 and/or a plurality of substrates 16 , and each device layer 12 may be made of the same or different materials. Material 16 may be made of the same or different materials. In one ideal and non-limiting implementation or example, the number of device layers 12 and the number of substrates 16 may be different. In one example, illustratively from piezoelectric layer 8 or optional lower conductive layer 10 to carrier 14, resonator body 4 may include device layer 12-1, substrate 16-1, device layer 12 as a resonator body 4's bottom layer. Examples of materials that can be used for each device layer 12 and each base material 16 are described below.

In an ideal and non-limiting implementation or example, as shown in FIGS. 1-3, one or more temperature compensation layers 90, 92, 94 may be on the top surface of the upper conductive layer 6; on the piezoelectric layer 8 or on the top surface of the upper conductive layer 6; Optionally between lower conductive layers 10, and device layer 12; and/or between device layer 12 (or 12-1) and substrate 16 (or 16-1). Each temperature compensation layer may contain at least one of silicon and oxygen. For example, each temperature compensation layer may contain silicon dioxide, or a silicon element, and/or an oxygen element. One or more optional temperature compensation layers 90, 92, 94 may help avoid resonant frequency changes due to the use of heat generated by the resonator body 4 of the examples shown in Figures 1-3.

In plan view, the resonator body 4 and/or the UBAR 2 described in the present invention may have the shape of a cube or a rectangular parallelepiped. However, other shapes of the resonator body 4 and/or the UBAR 2 are envisaged.

As shown in FIGS. 4A-4C and following all preceding figures, in one ideal and non-limiting implementation or example, one or both conductive layers 6 and optional conductive layers 10 may be represented by interdigitated electrodes 18 ( FIG. 4A ), which may include conductive wires or springs 20 , supported by the back 22 , interdigitated with the conductive wires or springs 24 , and supported by the back 26 . In one ideal and non-limiting implementation or example, one or both conductive layers 6 and optional conductive layers 10 may be represented by comb electrodes 27 ( FIG. 4B ), which may include a backside 30 Conductive wire or shrapnel 28 that extends over. The ends of the conductive wires or springs 28 on the opposite side of the first back 30 may be connected to an optional second back 32 (shown in phantom in Figure 4B). In one ideal and non-limiting implementation or example, one or both of the conductive layers 6 and optionally the conductive layer 10 may be presented in the form of conductive sheet electrodes 33 (FIG. 4C). The lines or clips 20, 24 and 28 are presented as straight lines. In one example, each wire or clip 20, 24 and 28 may be an arcuate wire or clip, a helical wire or clip, or other suitable and/or desired shape.

In an ideal and non-limiting implementation form or example, the upper conductive layer 6 may be in the form of interdigitated electrodes 18 , or comb-shaped electrodes 27 or sheet-shaped electrodes 33 . Independent of the form of the upper conductive layer 6 , the optional bottom conductive layer 10 may be presented in the form of interdigitated electrodes 18 , or comb electrodes 27 or sheet electrodes 33 . In the following, for descriptive purposes only, in an ideal and non-limiting implementation or example, the upper conductive layer 6 will be described as being presented in the form of a comb-shaped electrode 27, which includes a first backside 30 and an optional first backside 30. The two backsides 32 , and optionally the lower conductive layer 10 will be described in the form of sheet electrodes 33 . However, this embodiment is not limited to this, and any one of the interdigitated electrodes 18 , the comb-shaped electrodes 27 or the sheet-shaped electrodes 33 can be used as the upper conductive layer 6 , and the interdigitated electrodes 18 , the comb-shaped electrodes 27 or the sheet-shaped electrodes 33 can also be used as the upper conductive layer 6 . Any one of the electrodes 33 is incorporated as an optional lower conductive layer 10 .

In an ideal and non-limiting embodiment or example, the resonant frequency of the resonator body 4 having at least the upper conductive layer 6 in the form of interdigitated electrodes 18 or comb electrodes 27 in each example, regardless of the optional lower conductive layer The form of 10 can be adjusted or selected in a conventional manner by appropriately selecting the finger spacing 38 (eg, FIGS. 4A-4B ), wherein the finger spacing 38 = finger width + finger gap (between two adjacent fingers). In one example, the resonant frequency of the resonator body 4 may be increased by reducing the finger spacing 38 in the transverse mode relative to the thickness mode, primarily for each, but not all, of the desired resonator bodies 4 . In one example, the resonant frequency of the resonator body 4 may be reduced by increasing the finger spacing 38 in the thickness mode, relative to the transverse mode, for each, but not all, of the desired resonator bodies.

來計算。 In an ideal and non-limiting implementation or example, the resonator body 4 of each example may be in a thickness mode, a transverse mode, or a mixed/composite mode of a combination of thickness and transverse modes. For thickness mode resonance, the acoustic wave resonates in the thickness direction of the piezoelectric layer 8, and the resonance frequency is based on the thickness of the piezoelectric layer 8, and the thickness of the upper conductive layer 6 and optionally the lower conductive layer 10. The combination of piezoelectric layer 8, optional lower conductive layer 10, and upper conductive layer 6 may be referred to as a piezoelectric stack. The sound velocity determined by the resonant frequency of the resonator body 4 of the examples described here is the composite sound velocity of the piezoelectric stack. In one example, the resonant frequency f can be determined by dividing the composite sound velocity _Va by twice the thickness of the piezoelectric stack

to calculate.

_L減小到小間距尺寸

_S時，頻率增加的百分比，PFI _計算，在一個例子中，可以由下述公式計算 PFI _Calculated = (

_L-

_S) /

_S. 在一個例子中，當指間距38從2.2μm減小到1.8μm時，橫向模式的PFI _計算為22.2％。在另一個例子中，當指間距38從1.8μm減小到1.4μm時，橫向模式的PFI _計算為28.5％。 For transverse mode resonance, the acoustic wave resonates in the transverse direction (x or y direction) of the piezoelectric layer 8, and the resonance frequency can be obtained by dividing the composite sound velocity _Va of the piezoelectric stack by twice the finger spacing 38, f = V _a /2 (referring to the spacing). When the finger spacing is changed from the large spacing size

_L reduced to fine pitch size

When _S , the percentage of frequency increase, PFI _{is calculated} , in one example, PFI can be calculated by the following formula _Calculated = (

_L -

_S ) /

_S. In one example, when the finger pitch 38 was reduced from 2.2 μm to 1.8 μm, the PFI for the lateral mode was _calculated to be 22.2%. In another example, when the finger pitch 38 is reduced from 1.8 μm to 1.4 μm, the PFI for the lateral mode is _calculated to be 28.5%.

_L至小間距尺寸

_S，得到增加頻率的實際比率或測量百分比（PFI _測量）與增加頻率的計算比率（PFI _計算），二者之間的比例來定義。如果存在一個或多個不受控制或不可預見的變化，則橫向模式共振L值可以大於100％。在一例子中，共振器本體4可以在厚度模式、橫向模式或複合模式共振。在複合模式共振的例子中，橫向模式共振的部分 L可以≥20％。在複合模式共振的另一個例子中，橫向模式共振的部分 L可以≥30％。在複合模式共振的另一個例子中，橫向模式共振的部分 L可以≥40％。 Composite mode resonances may include portions of thickness mode resonances and portions of transverse mode resonances. The portion L of the transverse mode resonance in the compound mode resonance can be changed from the large pitch size by changing the finger pitch 38

_L to small pitch size

_S , to get the actual ratio of increased frequency or measured percentage (PFI _measurement ) to the calculated ratio of increased frequency (PFI _calculation ), defined by the ratio between the two. If there are one or more uncontrolled or unpredictable changes, the transverse mode resonance L value can be greater than 100%. In one example, the resonator body 4 may resonate in a thickness mode, a transverse mode or a composite mode. In the case of compound mode resonance, the fraction L of transverse mode resonance may be > 20%. In another example of compound mode resonance, the fraction L of transverse mode resonance may be > 30%. In another example of compound mode resonance, the fraction L of transverse mode resonance may be > 40%.

In an ideal and non-limiting embodiment or example, a resonator body 4 has an optional lower conductive layer 10 in the form of sheet electrodes 33 and an upper conductive layer 6 in the form of comb electrodes 27 , where the 2.2 μm finger spacing 38 can resonate in a composite mode with the following mode resonance frequencies: Mode 1 resonance frequency = 1.34 GHz; Mode 2 resonance frequency = 2.03 GHz; and Mode 4 resonance frequency = 2.82 GHz.

In one example, a resonator body 4 has an optional lower conductive layer 10 in the form of sheet electrodes 33 and an upper conductive layer 6 in the form of comb electrodes 27, wherein the 1.8 μm finger pitch 38 can be Resonates in a composite mode with the following mode resonance frequencies: Mode 1 resonance frequency = 1.49 GHz; Mode 2 resonance frequency = 2.38 GHz; and Mode 4 resonance frequency = 3.05 GHz. In this example, the transverse mode resonance L percentages of composite mode resonances may be: L-mode 1 = 53%; L-mode 2 = 78%; and L-mode 4 = 27%, respectively. See also Figure 10, which is a graph of frequency versus dB for the resonator body 4 in this example. In Figure 10, each peak 82, 84 and 88 represents the response of resonator body 4 to a different mode, mode 1 resonance frequency = 1.49 GHz; mode 2 resonance frequency = 2.38 GHz; and mode 4 resonance frequency = 3.05 GHz.

In one example, the mode 1 resonant frequency may or alternatively be considered or associated with a surface acoustic wave (SAW); the mode 2 resonant frequency may or alternatively be considered or associated with the _S0 (or Extensional) mode; and The mode 4 resonance frequency may or alternatively be considered or related to the A1 ₍ or Flexural) mode. Additionally, the Mode 3 resonance frequency (described below) may or alternatively be considered or associated with the Shear mode. SAW, S ₀ mode, expansion mode, A ₁ mode, shear mode and flexure mode are known to those of ordinary skill and will not be further described here.

In one example, a resonator body 4 has an optional lower conductive layer 10 in the form of a sheet electrode 33 and an upper conductive layer 6 in the form of a comb electrode 27, where the 1.4 μm finger spacing 38 can be used in the composite Resonance in mode with the following mode resonance frequencies: Mode 1 resonance frequency = 1.79 GHz; Mode 2 resonance frequency = 2.88 GHz; and Mode 4 resonance frequency = 3.36 GHz. For the resonator body 4 of this example, the transverse mode resonance percentage of the composite mode resonance L may be: L-mode 1 = 70%; L-mode 2 = 74%; and L-mode 4 = 35%.

In one example, the aforementioned resonator body 4 in thickness mode, transverse mode, or composite mode can be applied to each of the UBAR 2 examples shown in FIGS. 1-3 , which can include a resonator body 4 and one or more The connection structures 34 and 36 are combined, the details of which will be described below.

Next, referring to FIGS. 1-3 , in an ideal and non-limiting implementation or example, the bottom-most resonator bodies 4 shown in FIGS. 1-3 can be directly mounted using any suitable and/or desired mounting technique. Mounted on carrier 14, eg eutectic mount, adhesive, etc. Herein, "directly mounted", "directly mounted" and similar phrases may be understood to mean that the bottommost layer of each resonator body 4 shown in Figs. 1-3 is immediately adjacent to the The carrier 14 is placed and bonded to the carrier 14, such as, in one example, mounting, connecting, and/or by suitable and/or desired methods, such as, in one example, eutectic bonding, conductive adhesive, non- Conductive adhesives, etc. In one ideal and non-limiting implementation or example, the carrier 14 may serve as a surface of a package, such as a conventional integrated circuit (IC) package. After the bottommost layer of the resonator body 4 is mounted to the surface of the aforementioned package, the resonator body 4, and generally, the UBAR 2, is sealed in the aforementioned package in a conventional manner to protect the resonator body 4, and more generally against External environmental conditions protect the UBAR 2. In one example, the package uses a conventional ceramic IC package from Japanese business NTK Ceramic Co., Ltd. for mounting the UBAR. However, this should not be construed in a limiting sense as it is envisaged that the resonator body 4 and/or the UBAR 2 may be mounted in any suitable and/or desired package, now known or later developed.

In another example, the carrier 14 may serve as the surface of a substrate, eg, a ceramic sheet, a conventional sheet of printed circuit board material, or the like. The bottommost layers of the resonator body 4 and/or UBAR 2 of FIGS. 1-3 in each of the substrate examples described herein may be mounted and are for illustrative purposes only and should not be construed as limiting. The carrier 14 can be made of any suitable and/or desired material that is compatible with the bottommost material of each resonator body 4 and/or UBAR 2 shown in FIGS. 1-3 and can The resonator body 4 and/or the UBAR 2 are used in a known manner. The carrier 14 may be in any form deemed suitable and/or desired by one of ordinary skill in the art. Accordingly, this specification is not limiting with respect to the mounting substrate or carrier 14 .

1-3, in one ideal and non-limiting implementation or example, each UBAR 2 may include one or more optional connecting structures 34 and/or 36 that facilitate the application of electrical signals to the upper conductive layer 6 and optionally the lower conductive layer 10 of the resonator body 4 . However, in an ideal and non-limiting implementation or example, one or more of the optional connection structures 34 and/or 36 may be excluded (eg, not provided), wherein the electrical signal may be applied directly to the resonator body 4 upper conductive layer 6 and optional lower conductive layer 10. Thus, in one example, UBAR 2 may include resonator body 4 without connecting structures 34 and 36 . In another example, the UBAR 2 may include the resonator body 4 and a separate connecting structure 34 or 36 . For the purpose of describing the present invention in detail, the UBAR 2 includes an ideal and non-limiting implementation form or example of the resonator body 4 and the connecting structures 34 and 36 in the following description.

The respective connecting structures 34 and 36 may be in any suitable and/or desired form, may be formed by any suitable and/or desired method, and may be fabricated from any suitable and/or desired material , these materials can help provide independent electrical signals to the upper conductive layer 6 and optionally the lower conductive layer 10 . In one example, the upper conductive layer 6 is in the form of a comb-shaped electrode 27 having only one back 30 or 32 , and the optional lower conductive layer 10 is one of only one back 30 or 32 , or a sheet electrode 33 . In the form of comb electrodes 27, electrical signals may be provided to each upper conductive layer 6 and optionally lower conductive layer 10 via a single connection structure 34 or 36, which may be configured to correspond to the upper conductive layer, respectively 6 and optional lower conductive layer 10 provide electrical signals.

In another example, wherein at least one of the upper conductive layer 6 or optionally the lower conductive layer 10 has the form of an interdigitated electrode 18 or a comb electrode 27 and has two backsides 30 and 32 by means of individual connecting structures 34 and 36 to provide one or more electrical signals to the backs 24 and 26 of the interdigitated electrodes 18 and/or the backs 30 and 32 of the comb electrodes 27, respectively. The form of upper conductive layer 6 and optional lower conductive layer 10 and the manner in which electrical signals are provided to upper conductive layer 6 and optional lower conductive layer 10 should not be limiting.

In an ideal and non-limiting implementation or example, and not bound by any particular description, example, or theory, examples of the first and second connecting structures 34 and 36 may be similar to the UBARs 2 shown in FIGS. 1-3 . Examples used together will be described below.

In one ideal and non-limiting embodiment or example, and merely to illustrate the invention in detail, as shown in FIGS. 1-3, each of the connecting structures 34 and 36 will be described as having various layers and/or extensions of the substrate Various examples of the resonator body 4 are formed. This is not intended to be limiting, however, as it is envisaged that each connection structure 34 and 36 may have any suitable and/or desired form and/or structure that can be used for the upper conductive layer 6 and optionally the lower conductive layer 10. Provide one or more individual electrical signals.

In one ideal and non-limiting implementation or example, shown in FIGS. 5A-5B, which are representative graphs along the lines A-A and B-B in any or all of FIGS. 1-3, Upper conductive layer 6 in the form of comb electrodes 27 on top of layer 8, including backside 30 and optionally backside 32. In one example, the upper conductive layer 6 may optionally be present in the form of interdigitated electrodes 18 . In an ideal and non-limiting implementation or example, FIG. 5B shows that the optional lower conductive layer 10 under the piezoelectric layer 8 is in the form of a sheet electrode 33 (shown by the dashed line in FIG. 5B ). In one example, the optional lower conductive layer 10 may optionally be presented in the form of interdigitated electrodes 18 or comb electrodes 27 . The following are examples only, the upper conductive layer 6 and optionally the lower conductive layer 10 will be respectively described as being presented in the form of comb electrodes 18, including backside 30 and optional backside 32, and in the form of sheet electrodes 33, respectively render. However, this will not be limiting.

In an ideal and non-limiting implementation or example, the connection structures 34 and 36 may include bottom metal layers 40 and 44 ( FIG. 5B ) contacting the sheet electrode 33 formed as a part of the resonator body 4 Optional lower conductive layer 10 . Each of the bottom layers 40 and 44 may be sheet-like and covered with the piezoelectric layer 8 . In one example, each of the bottom layers 40 and 44 may be formed simultaneously as an extension of the sheet electrode 33 . In another example, each of the bottom layers 40 and 44 may be formed from the sheet electrode 33 , respectively, and may be of the same or different material as the sheet electrode 33 . In one example, connection structures 34 and 36 may also include top metal layers 42 and 46 on top of piezoelectric layer 8 and backsides 30 and 46 respectively contacting comb electrodes 27 formed as conductive layers 6 over resonator body 4 Back 32.

In one example, the bottom metal layers 40 and 44 may be connected to the contact pads 48 on the top surfaces of the first and second connection structures 34 and 36 via conductive vias 50 formed in the piezoelectric layer 8, the conductive vias 50 extends between the aforementioned contact pads 48 and the bottom metal layers 40 and 44 . For example, each of the top metal layers 42 and 46 may have a sheet shape and be separated from the corresponding contact pad 48 by a gap (not numbered). Each of the top metal layers 42 and 46 may also include a contact pad 58 . The contact pads 48 may be connected, as desired, to a suitable signal source (not shown) which may be electrically driven/biased in any suitable and/or desired manner. Lower conductive layer 10 . Likewise, the contact pads 58 can be connected, as desired, to a suitable signal source (not shown) that can be electrically driven/biased in any suitable and/or desired manner upper conductive layer 6 .

As shown in element codes 18 and 27 in FIGS. 5A-5B , the upper conductive layer 6 can also be in the form of interdigitated electrodes 18 , and the optional lower conductive layer 10 can also be in the form of comb-shaped electrodes 27 or interdigitated electrodes 18 .

As shown in Figures 6A-6B, which are representative graphs along the lines A-A and B-B in any or all of Figures 1-3, in one ideal and non-limiting implementation or example, Figures 6A-6B The example is similar to the example in Figures 5A-5B, except for at least the following differences. Bottom metal layers 40 and 44 may each be in the form of a pair of spaced-apart conductors 52 (relative to the conductive sheets shown in FIGS. 5A-5B ) connected to sheet electrodes 33 by lateral conductors 54 and tether conductors 56 The optional lower conductive layer 10. Top metal layers 42 and 46 may each be in the form of conductors 60 . Each conductor 60 may be connected to the backside 30 or the backside 32 of the comb electrode 27 formed as the upper conductive layer 6 by a tether conductor 62 . Tether conductor 62 may be vertically aligned with tether conductor 56 and separated from tether conductor 56 by piezoelectric layer 8 . In one example, as shown in FIGS. 6A-6B , the width of tether conductor 62 may be less than the width of tether conductor 60 , and the width of tether conductor 56 may be approximately the same as the width of tether conductor 62 .

As shown in Figures 7A-7B, which are representative graphs along the lines A-A and B-B in any or all of Figures 1-3, in one ideal and non-limiting implementation or example, Figures 7A-7B The example is similar to the example in Figures 6A-6B, except for at least the following differences. In part or all of the material of each connection structure 34 and 36 on both sides of the tether conductors 62 and 56, the connection structure portion may be removed, thereby forming a groove, which can be used in the remaining part of the connection structure and the resonator body 4 In between, on both sides of the aforementioned tether conductors extend part or all of the distance from the top to the bottom of the UBAR 2 . In one example, the removal of some or all of the material from each of the connection structures 34 and 36 on both sides of the tether conductors of the aforementioned connection structures defines tether structure 76 , which may include tether conductors 62 and 56 And a portion of the piezoelectric layer 8 is vertically aligned with the tether conductor 62 .

7C and with continued reference to FIGS. 7A-7B, in one ideal and non-limiting implementation or example, some or all of the material of each connection structure 34 and 36 is removed on both sides of the tether conductors 62 and 56, The aforementioned connection structure can be used with any of the UBAR 2 examples in Figures 1-3. For example: FIG. 7C is a side view of the example of UBAR 2 in FIG. 1 , in the material of the first and second connection structures 34 and 36 on both sides of the tether conductors 62 and 56 , with the aforementioned removed as shown in FIGS. 7A-7B . Connect the structural parts. As can be understood from FIGS. 7A-7C, on both sides of the tether conductors 62 and 56 of the aforementioned connection structures, the material removed from each connection structure 34 and 36 may include the upper conductive layer 6, the piezoelectric layer 8, the optional Portions of the lower conductive layer 10 and the device layer 12, therefore, are not visible in the trenches formed by removing the respective connection structures 34 and 36 on both sides of the tether conductors 62 and 56 of the aforementioned connection structures in FIGS. 7A-7B s material. In the example shown in FIGS. 7A-7C , each tether structure 76 may include, from top to bottom: tether conductor 62 , a portion of piezoelectric layer 8 vertically aligned with tether conductor 62 , optional tether conductor 56 (when lower conductive layer 10 is present), and the portion of device layer 12 that is vertically aligned with tether conductor 62 .

In another example, wherein UBAR 2 includes substrate 16 (FIG. 2), shown in phantom in FIG. 7C and optionally one or more additional device layers 12-1 and/or substrate 16-1 (FIG. 3) , in the forming material of each additional device layer 12-1 and/or substrate 16-1 (FIG. 3) and substrate 16 on both sides of tether conductors 62 and 56, each connection structure 34 and 36 may also be removed portion, so there is no visible material in the trenches formed by the removal of each connection structure 34 and 36 on both sides of the tether conductors 62 and 56 of the aforementioned connection structures in FIGS. 7A-7B.

In one example, FIGS. 7A-7B are diagrams of the example UBAR 2 of FIG. 2 , each tether structure 76 may include, from top to bottom, a portion of the tether conductor 62 , the piezoelectric layer 8 and the portion of the tether conductor 62 that are vertically aligned , optional tether conductors 56 (when optional lower conductive layer 10 is present), portions of device layer 12 vertically aligned with tether conductors 62 , and portions of substrate 16 vertically aligned with device layer 12 . In another example, FIGS. 7A-7B are diagrams of the example UBAR 2 in FIG. 3 , each tether structure 76 may include, from top to bottom, a tether conductor 62 , a piezoelectric layer 8 that is vertically aligned with the tether conductor 62 . portion, optional tether conductor 56 (when optional lower conductive layer 10 is present), portion of device layers 12 and 12-1 vertically aligned with tether conductor 62, and substrate 16 and 16-1 and tether The portion of conductor 62 that is vertically aligned.

As shown in Figures 8A-8B, which are representative graphs along the lines A-A and B-B in any or all of Figures 1-3, in one ideal and non-limiting implementation or example, Figures 8A-8B The example is similar to the example in Figures 7A-7B, except for at least the following differences. That is, the material forming all or part of the at least one device layer 12 or 12-1 of each connection structure 34 and 36 remains on both sides of the tether conductors 62 and 56 of the aforementioned connection structure, so the aforementioned at least one device layer 12 or The material of 12-1 can be seen in the grooves on both sides of the tether conductors 62 and 56 of the aforementioned connection structure. In one example, FIGS. 8A-8C are diagrams of the example UBAR 2 in FIG. 1 , each tether structure 76 may include, from top to bottom, a portion of the tether conductor 62 , the piezoelectric layer 8 and the portion of the tether conductor 62 that are vertically aligned , optional tether conductor 56 (when optional lower conductive layer 10 is present). In this example, the device layer 12 is retained in the trenches and can be seen in Figures 8A-8B.

In another example, FIGS. 8A-8B are diagrams of the UBAR 2 example of FIG. 2 , each tether structure 76 may include, from top to bottom, a tether conductor 62 , a piezoelectric layer 8 that is vertically aligned with the tether conductor 62 . portion, optional tether conductor 56 (when optional lower conductive layer 10 is present), portion of device layer 12 vertically aligned with tether conductor 62 . In this example, the device layer 12 is retained in the trenches and can be seen in Figures 8A-8B, and the substrate 16 under the device layer 12 is also retained (shown in dashed lines in Figure 8C), but not visible in Figures 8A-8B groove.

In another example, FIGS. 8A-8B are diagrams of the example of UBAR 2 in FIG. 3 , each tether structure 76 may include, from top to bottom, a tether conductor 62 , a piezoelectric layer 8 that is vertically aligned with the tether conductor 62 . portion, optional tether conductor 56 (when optional lower conductive layer 10 is present), portion of device layer 12 vertically aligned with tether conductor 62 . In one example, the device layer 12 is retained and visible in the trenches of FIGS. 8A-8B, and the substrate 16 underlying the device layer 12 is also retained, but not visible in the trenches of FIGS. 8A-8B, each tether Structure 76 also includes portions of device layer 12 - 1 and substrate 16 - 1 that are vertically aligned with tether conductors 62 . In another example, device layer 12-1 is retained and visible in the trenches of FIGS. 8A-8B, and substrates 16, 16-1 and device layer 12 are also retained but not visible in the trenches of FIGS. 8A-8B.

As another example, as shown in FIG. 8D, the diagram of the example of UBAR 2 in FIG. 1 or 2, each tether structure 76 may include from top to bottom: tether conductor 62, piezoelectric layer 8 and tether conductor 62 vertically aligned Portions, optional tether conductors 56 (when optional lower conductive layer 10 is present), portions of the body of device layer 12 vertically aligned with tether conductors 62, by partially removing the The device layer 12 on both sides of the tether conductors 62 and 56 exposes the portion of the device layer 12 that is vertically aligned with the tether conductor 62 . Where the example of FIG. 8D is the UBAR 2 shown in FIG. 2 , the substrate 16 (shown in phantom in FIG. 8D ) may be left under the device layer 12 but not visible in FIGS. 8A-8B .

In another example, the UBAR 2 example referred to in FIG. 3 , each tether structure 76 may include, from top to bottom, a tether conductor 62 , a portion of the piezoelectric layer 8 vertically aligned with the tether conductor 62 , an optional Tether conductor 56 (when optional lower conductive layer 10 is present), the body of device layer 12 or the portion of device layer 12-1 that is vertically aligned with tether conductor 62, by partial removal at each connection structure 34 and 36 Device layer 12 or device layer 12-1 on both sides of tether conductors 62 and 56 (similar to FIG. 8D partially removing device layer 12) to expose the body of device layer 12 or device layer 12-1 and tether conductor 62 Vertically aligned sections. In one example, when a part of the body of the device layer 12 of the UBAR 2 shown in FIG. 3 is removed (similar to the partial removal of the device layer 12 in FIG. 8D ), the inner part of the forming material of the device layer 12 of the UBAR 2 in FIG. 3 is shown in FIG. As seen in the trenches in 8A-8B, each tether structure 76 may also include portions of device layer 12-1 and substrate 16-1 that are vertically aligned with tether conductors 62. In this example, the substrate 16 is retained, ie no portion of the substrate 16 has been removed, which will not be shown in Figures 8A-8B.

In another example, when a portion of the body of the device layer 12-1 of the UBAR 2 shown in FIG. 3 is removed (similar to the partial removal of the device layer 12 in FIG. 8D ), the inner portion of the forming material of the device layer 12-1 is shown in FIG. 8A . As seen in the trenches in -8B, each tether structure 76 may also include a portion of the device layer 12-1 that is vertically aligned with the tether conductor 62. In this example, the substrates 16, 16-1 and the device layer 12 are retained, ie no portions of the substrates 16, 16-1 and the device layer 12 are removed, which will not be shown in Figures 8A-8B .

Referring to Figures 9A-9B, which are representative views along the lines A-A and B-B in any or all of Figures 1-3, the UBAR 2 of Figure 2 in an ideal or non-limiting implementation or example, Figures 9A-9B The example shown is similar to that of Figures 8A-8B, with at least the following exceptions. Each tether structure 76 may comprise a portion of the device layer 12 forming material, wherein as shown in FIGS. 9A-9C , portions of the substrate 16 can be seen formed on both sides of the tether conductors 62 and 56 of each connection structure 34 and 36 in the groove. In this example, substrate 16 is retained and each tether structure 76 may include, from top to bottom: tether conductor 62 , portion of piezoelectric layer 8 vertically aligned with tether conductor 62 , optional tether conductor 56 (when the optional lower conductive layer 10 is present), and the portion of the device layer 12 that is vertically aligned with the tether conductor 62 .

9A-9B, in an ideal and non-limiting implementation or example of the UBAR 2 shown in FIG. 3, the device layer 12 and the substrates 16, 16-1 are retained as shown in FIGS. 9A-9B, Substrate 16 - 1 can be seen in trenches formed on both sides of tether conductors 62 and 56 of each connection structure 34 and 36 . In this example, each tether structure 76 may include, from top to bottom: tether conductor 62, a portion of piezoelectric layer 8 vertically aligned with tether conductor 62, optional tether conductor 56 (when optional the lower conductive layer 10), and the portion of the device layer 12-1 that is vertically aligned with the tether conductor 62.

In another example, the UBAR 2 shown in FIG. 3 in which the substrate 16 is retained, the substrate 16 is visible on both sides of the tether conductors 62 and 56 of the respective connecting structures 34 and 36 in FIGS. 9A-9B . In the grooves formed, each tether structure 76 may include, from top to bottom: tether conductor 62, a portion of piezoelectric layer 8 vertically aligned with tether conductor 62, optional tether conductor 56 (when optional the lower conductive layer 10), the portion of the device layer 12-1 vertically aligned with the tether conductor 62, the portion of the substrate 16-1 vertically aligned with the tether conductor 62, and the portion of the device layer 12 vertically aligned with the tether conductor 62 part.

In another example shown in FIG. 9D , the example of UBAR 2 shown in FIG. 2 , at the interface of the substrate 16 and the device layer 12 , it can be removed laterally below the resonator body 4 and the connecting structures 34 and 36 A portion of the body of the substrate 16 forms the material, wherein as shown in FIG. 9D , the bottoms 64 and 70 of the connecting structures 34 and 36 are exposed, the bottoms 66 and 68 of the resonator body 4 are exposed, and the surfaces 72 and 70 of the body of the substrate 16 are exposed. 74 were exposed. In this example, the portion of the substrate 16 body from which the material has been removed may extend to the plane of FIG. 9D and the material portion of the substrate 16 is vertically aligned with each tether structure 76 . In this example, each tether structure 76 may include, from top to bottom: tether conductor 62, a portion of piezoelectric layer 8 vertically aligned with tether conductor 62, optional tether conductor 56 (when optional the lower conductive layer 10 ), the portion of the device layer 12 vertically aligned with the tether conductor 62 , and the portion of the substrate 16 vertically aligned with the tether conductor 62 and close to the device layer 12 . In this example, surfaces 72 and 74 can be seen in the trenches of Figures 9A-9B.

In another alternative example, in the example of UBAR 2 shown in FIG. 3 , part of the forming material of the substrate 16 - 1 or 16 may be laterally removed under the resonator body 4 and the connecting structures 34 and 36 , similar to removing The forming material of substrate 16 in Figure 9D, wherein the forming material surfaces of substrate 16-1 or 16 (eg, surfaces 72 and 74) are exposed and visible in the trenches of Figures 9A-9B.

In one example, when the forming material surfaces (eg, surfaces 72 and 74) of the substrate 16-1 of the UBAR 2 example of FIG. 3 are exposed and visible in the trenches of FIGS. 9A-9B, each tether structure 76 may also be The portion of the device layer 12-1 that is vertically aligned with the tether conductor 62 and the substrate 16-1 form the portion of the material vertically aligned with the tether conductor 62 and proximate the device layer 12-1. In this example, only a portion of the body of the substrate 16-1 is removed to form each trench, and the device layer 12 and the substrate 16 are retained, that is, no portion of the device layer 12 and the substrate 16 is removed , not visible in Figures 9A-9B.

In another example, when the forming material surfaces (eg, surfaces 72 and 74 ) of the substrate 16 of the example of UBAR 2 in FIG. 3 are exposed and visible in the trenches shown in FIGS. 9A-9B , each tether structure 76 may also include portions of device layer 12-1 vertically aligned with tether conductors 62, portions of substrate 16-1 vertically aligned with tether conductors 62, portions of device layer 12 vertically aligned with tether conductors 62, substrate 16 The portion of the material that is vertically aligned with the tether conductor 62 and proximate the device layer 12 is formed. In this example, only a portion of the body of the substrate 16-1 is removed to form the grooves.

In one ideal and non-limiting implementation or example, the bottom metal layers 40 and 44 of the connection structures 34 and 36 need not be present when the lower conductive layer 10 is not present in the examples discussed above.

In an ideal and non-limiting implementation form or example, each of the aforementioned tether structures 76 may include at least the tether conductor 62 , the optional tether conductor 56 (when the optional lower conductive layer 10 is present), the only voltage The portion of the electrical layer 8 that is vertically aligned with the tether conductor 62 . In another desirable and non-limiting implementation or example, each tether structure 76 may include one or more of the following vertically aligned with the tether conductors 62: device layer 12, substrate 16, device layer 12-1 , and/or Substrate 16-1. However, it is not limiting here.

In an ideal and non-limiting implementation form or example, the resonator body 4 in each example shown in FIGS. 1-3 has at least one of the upper conductive layer 6 , the optional lower conductive layer 10 , and the lower part of the upper conductive layer 6 . The widths of the portions of the piezoelectric layer 8 may be the same. That is, alternatively, in one example, the width of device layer 12, substrate 16, device layer 12-1, and/or substrate 16-1 may be the same as the width of upper conductive layer 6, optional lower conductive layer 10, and the pressure The widths and/or dimensions of the electrical layers 8 are the same.

In an ideal and non-limiting implementation form or example, any one or a plurality of surfaces and/or any or a plurality of connecting structures 34 and/or of the resonator body 4 in any of the examples shown in FIGS. 1-3 One or all of the surfaces of 36 may be appropriately etched as appropriate and/or desired, desirably optimized for quality factor and/or insertion loss conditions for any of the UBAR 2 examples in Figures 1-3. For example, the upper and lower surfaces of the resonator body 4 in any of the examples shown in FIGS. 1-3 may be etched. That is, alternatively, any one or more of the sides of the resonator body 4 in the examples shown in FIGS. 1-3 may be etched, wherein the aforementioned sides are perpendicular to the plane.

In an ideal and non-limiting implementation form or example, wherein the upper conductive layer 6 , the optional lower conductive layer 10 , or both, are in the form of interdigitated electrodes 18 , a backside 22 of the aforementioned interdigitated electrodes 18 Either or 26 may be connected and driven by a suitable signal source, while the other back 22 or 26 may not be connected to the signal source. In another ideal and non-limiting embodiment or example, the upper conductive layer 6 , the optional lower conductive layer 10 , or both, are in the form of interdigitated electrodes 18 , a backside of the aforementioned interdigitated electrodes 18 . 22 can be connected and driven by a signal source, and a back 26 of the aforementioned interdigitated electrode 18 can be connected and driven by a second signal source. In one example, the second signal source may be the same as or different from the first signal source.

In one ideal and non-limiting implementation or example, the acoustic impedance of each instance of device layer 12 (or 12-1 ) may be ≥ 60 x 10 ⁶ Pa-s/m ³ . In another example, the acoustic impedance of an instance of each device layer 12 (or 12-1 ) may be ≥ 90 x 10 ⁶ Pa-s/m ³ . In another example, the acoustic impedance of an instance of each device layer 12 (or 12-1 ) may be ≥ 500 x 10 ⁶ Pa-s/m ³ . In an ideal and non-limiting implementation or example, the acoustic impedance of each substrate layer 16 may be ≤ 100×10 ⁶ Pa-s/m ³ . In another example, the acoustic impedance of each substrate layer 16 may be ≦60×10 ⁶ Pa-s/m ³ .

In one ideal and non-limiting implementation or example, the acoustic reflectivity (R) of the interface between the device layer 12, the piezoelectric layer 8, or the optional lower conductive layer 10 may be greater than 50%. In another example, the acoustic reflectivity (R) of the interface of device layer 12, piezoelectric layer 8, or optional lower conductive layer 10 may be greater than 70%. In another example, the acoustic reflectivity (R) of the interface of device layer 12, piezoelectric layer 8, or optional lower conductive layer 10 may be greater than 90%.

In an ideal and non-limiting implementation or example, the acoustic reflectivity (R) of the interface between the device layer 12 or 12-1, and the piezoelectric layer 8, or the optional lower conductive layer 10 may be greater than 70%. In one example, the interface reflectance R of any two layers 6 and 8; 8 and 10; 8 or 10 and 12 or 12-1; or 12 or 12-1 and 16 or 16-1, or device layer 12 or 12 The reflectivity R of the interface between -1 and substrate 16 or 16-1 can be calculated by the following equation:

R = ǀ (Zb-Za)/(Za+Zb) ǀ

where Za = the acoustic impedance of the first layer, eg: the piezoelectric layer 8 or optional lower conductive layer 10, which is located above the second layer; and

Zb = acoustic impedance of the second layer, eg: device layer 12.

Other examples of first and second layers may include examples of device layer 12 or 12-1 over substrate 16 or 16-1.

In one ideal and non-limiting implementation or example, the overall reflectivity (R) of any example of the resonator body 4 shown in FIGS. 1-3 may be >90%.

In one ideal and non-limiting implementation or example, the device layer 12 may be a diamond layer or SiC formed in the prior art. In one example, substrate 16 may be formed of silicon.

In an ideal and non-limiting implementation or example, the diamond-formed device layer 12 may be grown by chemical vapor deposition of diamond on the substrate 16 or 16-1 or a sacrificial substrate (not shown) . In an ideal and non-limiting implementation or example, optional lower conductive layer 10, piezoelectric layer 8, and upper conductive layer 6 may be deposited on device layer 12 and patterned as desired (eg, comb electrodes) 27 or the interdigitated electrode 18), the conventional semiconductor fabrication technology used by it will not be described here.

Here, each of the temperature compensation layers 90, 92, 94 may include at least one of silicon or oxygen. For example, each temperature compensation layer may contain silicon dioxide, or silicon element, and/or oxygen element.

In one ideal and non-limiting implementation or example, each of the UBARs 2 shown in FIGS. 1-3 may have an unloaded quality factor ≥ 100. In another example, each of the UBARs 2 shown in Figures 1-3 may have an unloaded quality factor ≥ 50. In an ideal and non-limiting implementation or example, the thicknesses of the piezoelectric layer 8, the device layers 12, and the substrate 16 of each example of the resonator body 4 shown in FIGS. 1-3 may be selected in any suitable and/or In the desired manner, the performance of the resonator body 4 is optimized. Likewise, in one example, the dimensions of the example resonator bodies 4 shown in FIGS. 1-3 may be selected according to target performance, by way of non-limiting example: insertion loss, power carrying capacity, and heat dissipation. In an ideal and non-limiting embodiment or example, when diamond is used as the material of the device layer 12, the interface of the surface of the diamond layer with the underlying layer 12 may be optically completed and/or physically dense. In one example, the diamond material forming device layer 12 may be undoped or doped, eg, P-type or N-type. The diamond material can be polycrystalline, nanocrystalline or super nanocrystalline. In one example, when silicon is used as the material for each of the substrate 16 instances, the aforementioned silicon may be undoped or doped, eg, P-type or N-type, and monocrystalline or polycrystalline. The diamond material forming the device layer may have a Raman half maximum width ≤ 20 cm ^-1 .

In an ideal and non-limiting embodiment or example, the piezoelectric layer 8 can be made of ZnO, AlN, InN, alkali metal or alkaline earth metal niobate, alkali metal or alkaline earth metal titanate, alkali metal or alkaline earth metal tantalum Iron ore, GaN, AlGaN, lead zirconate titanate (PZT), polymers or doped forms of any of the foregoing.

In one ideal and non-limiting implementation or example, the device layer 12 may be formed of any suitable and/or desired high acoustic impedance material. For example: a material with an acoustic impedance between 10 ⁶ Pa-s/m ³ and 630 x 10 ⁶ Pa-s/m ³ or above 630 x 10 ⁶ Pa-s/m ³ can be considered a high acoustic impedance material . Some non-limiting examples of typical high acoustic impedance materials that may be used, such as to form any of the device layers 12 described herein, may include: diamond (~630 x 10 ⁶ Pa-s/m ³ ); W (~99.7 x 10 ⁶ Pa-s/m ³ ); SiC; a condensed phase material such as a metal such as Al, Pt, Pd, Mo, Cr, Ir, Ti, Ta; an element of Group 3A or 4A of the Periodic Table; 1B of the Periodic Table , 2B, 3B, 4B, 5B, 6B, 7B or 8B transition elements; ceramics; glasses and polymers. This non-limiting list of high acoustic impedance materials is not limited thereto.

In one desirable and non-limiting implementation or example, substrate 16 may be formed of any suitable and/or desired low acoustic impedance material. For example: a material having an acoustic impedance between 10 ⁶ Pa-s/m ³ and 30 x 10 ⁶ Pa-s/m ³ can be considered a low acoustic impedance material. Some non-limiting examples of typical low acoustic impedance materials that may be used, such as forming any of the substrates ¹⁶ described herein, may comprise at least one ^of the following: ceramic; Acoustic impedance between ⁶ Pa-s/m ³ metal, glass, crystal, minerals; ivory (1.4 x 10 ⁶ Pa-s/m ³ ); alumina/sapphire (25.5 x 10 ⁶ Pa-s/m 3 ) ³ ); alkali metal K (1.4 x 10 ⁶ Pa-s/m ³ ); silica and silicon (19.7 x 10 ⁶ Pa-s/m ³ ). This non-limiting list of low acoustic impedance materials is not limited thereto.

In one ideal and non-limiting embodiment or example, depending on the choice of material for forming the resonator body 4 for each example, one or more materials generally considered to be high acoustic impedance materials may be used as the low acoustic resistance material. For example, when diamond or SiC is used as the material of the device layer 12 , W may be used as the material of the substrate 16 . Thus, by achieving the desired reflectivity R of the two-layer interface or resonator body 4 (as described above), it is possible to decide which materials can be used as high acoustic impedance and which as low acoustic impedance.

In an ideal and non-limiting embodiment or example, an integrated acoustic wave resonator may include a resonator body 4 in accordance with the principles of the present invention. The resonator body 4 may include a piezoelectric layer 8 ; a device layer 12 ; The entire surface of the device layer 12 opposite to the piezoelectric layer 8 is substantially used to mount the resonator body 4 on the carrier 14 separated from the resonator body 4 . In this example, it is desirable, but not necessary, that the entire surface of the device layer opposite the piezoelectric layer is used to mount the entire resonator body to the carrier. In this example, it may be desirable, but not necessary, for the BAW resonator to include connecting structures 34 or 36 to conduct signals to the upper conductive layer. In one example, the device layer may comprise diamond or SiC. In one example, the upper conductive layer 6 may include a plurality of conductive lines or elastic sheets with spaces. In one example, the aforementioned resonator body 4 may further include an optional lower conductive layer 10 positioned between the piezoelectric layer 8 and the device layer 12 .

In an ideal and non-limiting embodiment or example, the resonator body 4 may further include a substrate 16 connected to the aforementioned device layer 12 and the other side of the aforementioned device layer is the aforementioned piezoelectric layer 8 . In one example, the surface of the aforementioned device layer 12 may be entirely mounted into the aforementioned substrate 16 . In one example, the entire surface of the substrate 16 facing the aforementioned carrier 14 may be directly mounted into the aforementioned carrier 14 .

In an ideal and non-limiting embodiment or example, the surface of the device layer 12 facing the carrier 14 may be entirely mounted into the substrate 16 . In one example, the surface of the aforementioned device layer 12 facing the aforementioned carrier 14 may be entirely mounted into the aforementioned carrier 14 .

In an ideal and non-limiting embodiment or example, the resonator body 4 may further include a second device layer 12-1, which is located between the substrate 16 and the piezoelectric layer 8; or the second substrate 16-1 , which is located between the substrate 16 and the piezoelectric layer 8; or includes both.

In an ideal and non-limiting implementation or example, the use of "entirely mounted" herein may mean directly mounting one layer or substrate, or indirectly mounting another layer or substrate. In one example, the use of "entirely mounted" herein may mean or alternatively mean that no space or separation is intentionally reserved between one layer or substrate and another layer or substrate. In another example, use of "entirely mounted" herein may mean or alternatively include a naturally occurring space between one layer or substrate and another layer or substrate, which is naturally occurring and not intentionally fabricated.

Some non-limiting implementations or examples of UBAR have been described, and the first to sixth UBAR examples will be described here.

first UBAR Example: A mode 3 enabled device layer and or mode 4 Resonant and has a temperature compensation layer.

Referring to FIG. 1, in some non-limiting implementations or examples, a first UBAR2 example (shown in FIG. 1) may include from the top end to the carrier 14: a conductive line including a space between or between the elastic pieces 20 or 28 The upper conductive layer 6 (shown in FIGS. 4A to 4B ), the piezoelectric layer 8 formed of LiNbO ₃ , the temperature compensation layer 92 formed of SiO ₂ , and the device layer 12 formed of diamond or SiC. In one example, the finger pitch 38 (shown in FIGS. 4A-4B ) is 0.6 μm and the thickness of the piezoelectric layer 8 is 0.6 μm.

Throughout the present invention, the value of the variable "λ" may be based on one or more dimensions of the pattern or features defined by the upper conductive layer, or on the thickness of the piezoelectric layer 8. In some non-limiting implementations or examples, the λ value may be twice the finger spacing 38 or twice the thickness of the piezoelectric layer 8 (1.2 µm in this example). However, this should not be construed in a limiting sense as the λ value may be based on the thickness of one or more layers in each UBAR example described herein and/or any other suitable and/or desired size. In this example, the cutting angle of the piezoelectric layer 8 is 0° (or 180°), which is sometimes referred to as Y-cut or YX-cut. In some non-limiting implementations or examples, it can be envisaged that the cutting angle of the piezoelectric layer 8 is 0° (or 180°) ± 20°. Here, unless otherwise specified, the cutting angle of the piezoelectric layer 8 refers to the cutting angle rotated with respect to the X axis.

In some non-limiting implementations or examples, in order to mold the first UBAR2 example, for multiple or multiple different exemplary values of the thickness of the temperature compensation layer 92 formed of SiO ₂ , in the first UBAR2 example An exemplary electrical stimulation frequency sweep (eg: 1 GHz to 6.2 GHz) was performed to confirm frequency response (frequency vs. vibration). In a molding example, the thickness of the temperature compensation layer 92 formed by SiO ₂ is between (9/16)λ and (1/64)λ, and in various thickness values, an exemplary electrical stimulation frequency is performed in the first UBAR2 example is at least between 1 GHz and 6.2 GHz. In one example, a frequency sweep over at least 1 GHz to 6.2 GHz can determine a first graph, graph or relationship of frequency vs. vibration for temperature compensation layer 92 thickness such as (9/16)λ. In one example, a frequency sweep over at least 1 GHz to 6.2 GHz may determine another graph, graph or relationship of frequency vs. vibration for temperature compensation layer 92 thickness such as (3/64)λ. Frequency sweeps at different thicknesses of the temperature compensation layer 92 may determine additional frequency vs. vibration graphs, graphs or relationships.

At least the mode 4 resonant frequency 88 was observed in a graph, graph or relationship for each frequency vs. Zhenfu (FIGS. 10 and 11). In the first UBAR example, however, the mode 4 resonance frequency 88 was unexpectedly observed at 5.2 GHz (FIG. 11) relative to the mode 4 resonance frequency 88 observed at 3.05 GHz (FIG. 10), and the mode 3 resonance was observed at 3.13 GHz Frequency 86 (Figure 11).

In FIG. 11 , the resonance frequencies 82 and 84 of mode 1 and mode 2 (shown in FIG. 10 ) are omitted to the left of the resonance frequency 86 of mode 3 for the sake of brevity. However, it should be understood that in addition to the resonant frequencies 86 and 88 of mode 3 and mode 4, there may also be resonant frequencies 82 and 84 of mode 1 and mode 2 when the frequency sweep is at least 1 GHz and 6.2 GHz (Fig. 10). shown).

In some non-limiting implementations or examples, as shown in FIG. 11 , in each graph, graph or relationship of frequency vs. vibration, the mode 3 resonant frequency 86 includes a positive peak f _s1 and a negative peak f _p1 , the mode The resonant frequency 88 includes a positive peak _fs2 and a negative peak _fp2 .

For illustrative purposes only, the "resonant frequency" observed at "approximately" a particular frequency described herein may be any representative frequency of the positive peak f _s1 and the negative peak f _p1 for the mode 3 resonance frequency 86 . The resonance frequency 88 may be any representative value of the positive peak value f _s2 and the negative peak value f _p2 . Accordingly, any resonant frequency described herein as "about" a particular frequency should not be limited.

In some non-limiting implementations or examples, when the thickness of the temperature compensation layer 92 formed by SiO ₂ is (1/16)λ, the mode 3 coupling efficiency ( M3CE) and mode 4 coupling efficiency (M4CE) can be determined by the following equations EQ1 and EQ2, respectively: EQ1: Mode 3 coupling efficiency (M3CE) = (π ² /4)(( f _p1 – f _s1 )/ f _p1 ) EQ2: Mode 4 Coupling Efficiency (M4CE) = (π ² /4)(( f _p2 – f _s2 )/ f _p2 ) where, when the exemplary values of f _p1 and f _s1 are 3.738 GHz and 3.13 GHz, respectively, M3CE = _40.093 %; and when the exemplary values of fp2 and fs2 are 5.442 GHz and _5.172 GHz, respectively, M4CE = 12.229%.

However, since M3CE values ≥8%, ≥11%, ≥14%, ≥17%, or ≥20% are satisfactory, suitable and/or desirable, the aforementioned M3CE values in this example should not be limiting . Additionally or alternatively, since M4CE values ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8%, or ≥ 10% are satisfactory, suitable and/or desirable, the aforementioned M4CE values in this example are not should be restrictive.

In some non-limiting embodiments or examples, when a specific M3CE value such as ≥8%, ≥11%, ≥14%, ≥17% or ≥20% is desired, the cutting of the piezoelectric layer 8 The angle can extend beyond the above 0° (or 180°) ± 20°, for example: the cutting angle is 0° (or 180°) ≥ ± 20°, ≥ ± 30°, ≥ ± 40°, ≥ ± 50°, etc. In some non-limiting implementations or examples, the piezoelectric layer 8 is not limited, such as LiNbO ₃ crystal, and the desired cutting angle produced from Z-cut or X-cut may also be sufficient to obtain the specific desired value of M3CE.

In some non-limiting embodiments or examples, when a specific M4CE value such as ≥3%, ≥4%, ≥6%, ≥8% or ≥10% is desired, the cutting of the piezoelectric layer 8 The angle can extend beyond the above 130° ± 30° (sometimes called Y cut 130 ± 30 or YX cut 130 ± 30), for example cutting angles are: 130° ≥ ± 30°, ≥ ± 40°, ≥ ± 50°, etc. . In some non-limiting implementations or examples, the piezoelectric layer 8 is not limited such as LiNbO ₃ crystal, and the desired cutting angle produced from Z-cut or X-cut may also be sufficient to obtain the specific desired value of M4CE.

In some non-limiting implementations or examples, equations EQ1 and EQ2 and the above-determined graphs, graphs or relationships of frequency vs. vibration are used to obtain a plurality of thickness values for the temperature compensation layer 92, determined by SiO ₂ . The formed temperature compensation layer 92 and the plurality of thickness values for optimizing the resonance frequencies of the mode 3 and the mode 4 are determined to be (3/64)λ and (1/32)λ, respectively. However, the thickness of the temperature compensation layer 92 formed by SiO ₂ can be any suitable and/or desired and non-limiting thickness, such as ≤1λ, ≤(1/2)λ, ≤(3/8)λ, ≤( 1/4)λ or ≤(1/8)λ, the thickness value should not be restrictive.

Second UBAR Example: A mode 3 enabled device layer and or mode 4 Resonant and without a temperature compensation layer.

In some non-limiting implementations or examples, for comparison and/or modeling purposes, an exemplary electrical stimulation frequency sweep (eg, 1 GHz to 6.2 GHz) was performed on a second UBAR2 instance to confirm frequency response, and The layers of the two UBAR2 examples are similar to the above-mentioned first UBAR2 example (as shown in FIG. 1 ), except that the second UBAR2 example does not include the temperature compensation layer 92 . Perform a frequency sweep to confirm a graph, graph or relationship of frequency vs. Zhenfu.

Using equations EQ1 and EQ2 and the frequency sweep identified frequency vs. Zhenfu graph, graph or relationship, the coupling efficiencies M3CE and M4CE for the mode 3 and mode 4 resonant frequencies 86 and 88 of the second UBAR2 example can be identified as: f _p1 When the values of f p2 and f _s1 are 3.738 GHz and 3.13 GHz, respectively, M3CE = 40.093%; when the values of f _p2 and f _s2 are 6.194 GHz and 5.96 GHz, respectively, M4CE = 9.312%.

However, since M3CE values ≥8%, ≥11%, ≥14%, ≥17%, or ≥20% are satisfactory, suitable and/or desirable, the aforementioned M3CE values of this example should not be limiting. Additionally or alternatively, since M4CE values ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8% or ≥ 10% are satisfactory, suitable and/or desirable, the aforementioned M4CE values of this example should not be Restrictive.

In some non-limiting implementations or examples, when a specific M3CE value is desired, such as ≥8%, ≥11%, ≥14%, ≥17%, or ≥20%, the cutting angle of the piezoelectric layer 8 can be Extend beyond the aforementioned cutting angle of 0° (or 180°) ± 20°, such as a cutting angle of 0° (or 180°) ≥ ± 20°, ≥ ± 30°, ≥ ± 40°, ≥ ± 50°, etc. In some non-limiting embodiments or examples, the piezoelectric layer 8 is not limited, for example, LiNbO ₃ crystal, and the desired specific M3CE value may also be obtained from the desired cutting angle of Z-cut or X-cut.

In some non-limiting implementations or examples, when a specific M4CE value is desired, such as ≥3%, ≥4%, ≥6%, ≥8%, or ≥10%, the cutting angle of the piezoelectric layer 8 can be Extends beyond 130° ± 30° (sometimes called Y cut 130 ± 30 or YX cut 130 ± 30), e.g. at cut angles: 130° ≥ ± 30°, ≥ ± 40°, ≥ ± 50°, etc. In some non-limiting implementations or examples, the piezoelectric layer 8 is not limited such as LiNbO ₃ crystal, and the desired cutting angle produced from Z-cut or X-cut may also be sufficient to obtain the specific desired value of M4CE.

From the M4CE values of UBAR2 with and without the above-mentioned temperature compensation layer 92, it can be understood that when the UBAR2 has the temperature compensation layer 92 formed of SiO ₂ , its coupling efficiency is higher, on the contrary, UBAR2 does not have the temperature compensation layer formed of SiO ₂ . When layer 92 is used, the coupling efficiency is less. In some non-limiting implementations or examples, generally speaking, it is more desirable to obtain a larger value of coupling efficiency.

Third UBAR Example: A mode 3 enabled device layer and or mode 4 It resonates and has a temperature compensation layer and an aluminum nitride layer.

Referring to Figure 12 with continued reference to Figure 11, in some non-limiting implementations or examples, for comparison and/or modeling purposes, exemplary electrical stimulation was performed on a third UBAR2 example (shown in Figure 12) Frequency sweep (ex: 1 GHz to 6.2 GHz) to confirm frequency response, the third UBAR2 example is similar in all aspects to the first UBAR2 example above, except that the third UBAR2 is at least the following: i.e., the third UBAR2 example is made of diamond A layer of aluminum nitride AlN 96 is included between the device layer 12 formed of SiC or the temperature compensation layer 92 formed of SiO ₂ , the temperature compensation layer 92 is on the aluminum nitride layer 96 (as shown in FIG. 12 ), nitrogen The thickness of the aluminum oxide layer 96 is (7/16)λ, the thickness of the temperature compensation layer 92 formed by SiO ₂ is (11/128)λ, and the thickness of the device layer 12 formed by diamond or SiC is (90/16)λ . In this example, λ corresponds to 1.6 µm. A frequency sweep is then performed to confirm a graph, graph or relationship of frequency vs. Zhenfu.

Using equations EQ1 and EQ2 and a graph, graph or relationship of frequency vs. Zhenfu identified by the frequency sweep, the coupling efficiencies M3CE and M4CE for the mode 3 and mode 4 resonant frequencies 86 and 88 of the third UBAR2 example in Figure 12 are identified as : When the values of f _p1 and f _s1 are 3.608 GHz and 3.032 GHz, respectively, M3CE = 39.351%; when the values of f _p2 and f _s2 are 5.02 GHz and 4.8 GHz, respectively, M4CE = 10.802%.

However, the aforementioned M3CE values in this example are not limiting, as M3CE > 8%, > 11%, > 14%, > 17% or > 20% may be satisfactory, suitable and/or desirable. Additionally or alternatively, the aforementioned M4CE values in this example are not limiting, as M4CE ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8% or ≥ 10% may be satisfactory, suitable and/or expected.

In some non-limiting implementations or examples, when a particular M3CE value such as ≥8%, ≥11%, ≥14%, ≥17% or ≥20% is desired, the cutting angle of the piezoelectric layer 8 can be extended Exceeds the aforementioned cutting angle of 0° (or 180°) ± 20°, for example, the cutting angle is 0° (or 180°) ≥ ± 20°, ≥ ± 30°, ≥ ± 40°, ≥ ± 50°, etc. In some non-limiting embodiments or examples, the piezoelectric layer 8 is not limited, for example, LiNbO ₃ crystal, and the desired specific M3CE value may also be obtained from the desired cutting angle of Z-cut or X-cut.

In some non-limiting implementations or examples, when a specific M4CE value is desired, such as ≥3%, ≥4%, ≥6%, ≥8%, or ≥10%, the cutting angle of the piezoelectric layer 8 can be Extends beyond 130° ± 30° (sometimes called Y cut 130 ± 30 or YX cut 130 ± 30), e.g. at cut angles: 130° ≥ ± 30°, ≥ ± 40°, ≥ ± 50°, etc. In some non-limiting implementations or examples, the piezoelectric layer 8 is not limited such as LiNbO ₃ crystal, and the desired cutting angle produced from Z-cut or X-cut may also be sufficient to obtain the specific desired value of M4CE.

In the above-mentioned first to third examples, the values of UBARs, M3CE and M4CE of the piezoelectric layer 8 formed by the LiNbO ₃ crystal cut at 0° (or 180°) were confirmed. In some non-limiting implementations or examples, Applicants have discovered that the piezoelectric layer ₈ formed of LiNbO3 crystals is cut at 130° (sometimes referred to as YX cut 130° or Y cut 130°) to enhance or optimize the mode 4. Coupling efficiency M4CE at resonant frequency 88. In one example, the cutting angle of the piezoelectric layer 8 formed of LiNbO ₃ crystal can be 130°±30°, for example, in the range of 100° to 160°; ideally, it is 130°±20°, such as 110° to 150°; ideally 130° ± 10°, eg, 120° to 140°. However, this ± value or range is not limiting.

In addition, in some non-limiting implementations or examples, the applicant found that when the UBAR 2 was formed, the piezoelectric layer 8 (which was formed of LiNbO ₃ crystal and was formed at about 130° (± 30°, or ± 20°, or ±10°) angle cutting) and device layer 12 (when substrate 16 is omitted) or substrate 16 (when device layer 12 is omitted) or both device layer 12 and substrate 16, with alternating low The coupling efficiency M4CE at the mode 4 resonant frequency 88 can be enhanced or optimized with a high acoustic impedance layer. In some non-limiting implementations or examples, the UBAR 2 having alternating low and high acoustic impedance layers may include a device layer 12 formed of diamond, SiC, W, Ir or AlN and a substrate formed of silicon 16. In some non-limiting implementations or examples, UBAR2 having alternating low and high acoustic impedance layers may include substrate 16 formed of silicon, but may exclude device layer 12 .

Fourth UBAR Example: A stack-enabled flex mode ( Mode 4) Contains at least one low acoustic impedance layer and one high acoustic impedance layer, and optionally a device layer.

Referring to FIG. 13 and with continued reference to FIG. 11, in some non-limiting implementations or examples, a fourth UBAR2 example (shown in FIG. 13) is composed of alternating layers of low and high acoustic impedance materials, which may include : between piezoelectric layer ₈ (formed from LiNbO crystal and cut at an angle of about 130° (± 30°, ± 20°, ± 10°)) and (optional) device layer 12 or substrate 16, It has a first low acoustic impedance layer 100 , a first high acoustic impedance layer 102 , a second low acoustic impedance layer 104 , a second high acoustic impedance layer 106 and a third low acoustic impedance layer 108 . In this example, the interdigitated conductive lines or elastic pieces 20 or 28 in the upper conductive layer 6 (as shown in FIGS. 4A and 4B ) have a finger spacing 38 of 1.2 µm, a λ value of 2.4 µm, and a piezoelectric layer thickness of λ /2. If the device layer 12 has a thickness of 4λ, and the substrate 16 has a thickness of 20 µm. In this example, the cutting angle of the piezoelectric layer 8 may be 100° to 160° for the purpose of molding.

In some non-limiting implementations or examples, each of the low acoustic impedance layers 100, 104, and 108 may be formed from silicon dioxide ( _SiO2 ), and each of the high acoustic impedance layers 102 and 106 may be formed from a metal, such as Tungsten (W), the device layer 12 can be formed from diamond or SiC, and the substrate 16 can be formed from silicon. In one example, the device layer 12 is optional, wherein the third low acoustic impedance layer 108 may directly contact the substrate 16 and the second high acoustic impedance layer 106 .

In some non-limiting implementations or examples, exemplary electrical stimulation frequency sweeps (eg, 1 GHz to 6.2 GHz) were performed on several fourth examples of UBARs 2 for molding purposes to confirm frequency responses (frequency vs. amplitude), with and without device layer 12, respectively, at multiple different cut angles from 100° to 160° at piezoelectric layer 8, at different exemplary levels of low acoustic impedance layers 100, 104, and 108 Thickness, different exemplary thicknesses in the high acoustic impedance layers 102 and 106, for example, in the manner described above for the first UBAR2. In other words, exemplary electrical stimulation frequency sweeps (eg: 1 GHz to 6.2 GHz) were performed on several fourth examples of UBARs 2 to confirm frequency responses (frequency vs. amplitude), with various combinations of the preceding UBARs 2 examples: (1 ) with the device layer 12 or without the device layer 12; (2) a plurality of different cutting angles of the piezoelectric layer 8 from 100° to 160°; (3) different thicknesses of the low acoustic impedance layers 100, 104 and 108; (4) ) different thicknesses of the high acoustic impedance layers 102 and 106.

In some non-limiting embodiments or examples, the cutting angles of the piezoelectric layer 8, the thicknesses of the low acoustic impedance layers 100, 104 and 108 are set at the same value (the first value), the high acoustic impedance The thicknesses of the resistive layers 102 and 106 are set at the same value (the second value), an exemplary electrical stimulation frequency sweep is performed on the fourth instance of UBARs 2, for example, at a frequency of 1 GHz to 6.2 GHz, and the fourth instance of UBARs 2 is recorded. frequency response. Next, changing only the thickness of the low acoustic impedance layer (the first value) or the thickness of the high acoustic impedance layer (the second value), the frequency sweep was repeated, and the response frequency of the fourth example of UBARs 2 was recorded. In order to characterize the frequency response of different thickness values of the low-acoustic impedance layer and the high-acoustic impedance layer of the fourth UBARs 2, the process was repeated several times for different thickness values of the low-acoustic impedance layer and the high-acoustic impedance layer. In some non-limiting implementations or examples, the different thickness values of the low acoustic impedance layers and/or the high acoustic impedance layers may be the same or different. In some non-limiting implementations or examples, diamond, SiC, W, Ir, AlN, etc. can be used as the high acoustic impedance material. A graph, graph, or relationship of frequency vs. amplitude is confirmed for each frequency sweep.

The ideal coupling efficiency M4CE at the mode 4 resonant frequency 88 of the fourth UBAR2 example in Figure 13 with and without With the device layer 12: For f _p2 and f _s2 of 5.43 GHz and 5.08 GHz, respectively, M4CE = 15.888% For example: the cut angle of the piezoelectric layer 8 is 130°, and the low acoustic impedance layers 100, 104 The thickness of 108 is (1/16)λ, and the thickness of each high acoustic impedance layer 102 and 106 is (1/16)λ.

Since M4CE values ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8%, or ≥ 10% may be satisfactory, suitable and/or desirable, the aforementioned M4CE values in this example should not be limiting. In one example, the M4CE value ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8% or ≥ 10% can be adjusted by adjusting the cutting angle of the piezoelectric layer 8 ± a suitable and/or desired value as previously described 130° ± 30°. In some non-limiting embodiments and examples, the piezoelectric layer 8 is not limited, such as LiNbO ₃ crystals produced from a desired cutting angle of Z-cut or X-cut, it is also possible to obtain a desired specific M4CE value.

In addition, the aforementioned thicknesses of each low acoustic impedance layer and/or each high acoustic impedance layer should not be limiting, as the aforementioned thicknesses of each low acoustic impedance layer and/or each high acoustic impedance layer may be suitable and /or desired thickness, for example, without limitation, may be ≤1λ, ≤(1/2)λ, ≤(3/8)λ, ≤(1/4)λ, or ≤(1/8)λ. The thickness of each low acoustic impedance layer and/or each high acoustic impedance layer may be different (or the same) as the thickness of any other low acoustic impedance layer and/or each high acoustic impedance layer. Therefore, there is no limitation when the thickness of the low acoustic impedance layer is the same, the thickness of the high acoustic impedance layer is the same, or the thickness of the low acoustic impedance layer and the thickness of the high acoustic impedance layer are the same.

Fifth UBAR Example: A stack-enabled flex mode ( Mode 4) Contains at least one low acoustic impedance layer and one high acoustic impedance layer, and optionally a device layer.

11 and 13, in some non-limiting implementations or examples, similar to the aforementioned fourth UBAR 2 example, for each of the piezoelectric layers 8 from 100° to 160°. At different cutting angles, for molding purposes, exemplary electrical stimulation frequency sweeps (eg, 1 GHz to 6.2 GHz) were performed at different thickness values of the low and high acoustic impedance layers of the fifth UBAR 2 example to Confirming the frequency response (frequency vs. amplitude), the aforementioned fifth UBAR 2 example is similar in every respect to the aforementioned fourth UBAR 2 example (shown in Figure 13) except that the low acoustic impedance layer 108 is omitted. A graph, graph, or relationship of frequency vs. amplitude is confirmed for each frequency sweep.

Ideal coupling efficiency M4CE for the mode 4 resonant frequency 88 of the fifth UBAR 2 example with and without device layer 12 using equation EQ2 and the frequency vs. Consistent with the fourth UBAR 2 example, namely: M4CE = 15.888% when f _p2 and f _s2 are 5.43 GHz and 5.08 GHz, respectively. When the cutting angle of the piezoelectric layer 8 is 130°, the thickness of each of the low acoustic impedance layers 100 and 104 is (1/16)λ, and the thickness of each of the high acoustic impedance layers 102 and 106 is (1/16)λ.

In some non-limiting implementations or examples, the thickness of each low acoustic impedance layer and/or the thickness of each high acoustic impedance layer may be the same or different. In some non-limiting implementations or examples, diamond, SiC, W, AlN, Ir, etc. can be used as materials for each of the high acoustic impedance layers.

Since M4CE values ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8%, or ≥ 10% are satisfactory, suitable and/or desired, the aforementioned M4CE values in this example should not be limiting . In one example, M4CE values ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8%, or ≥ 10% can be achieved by adjusting the cutting angle of the piezoelectric layer 8 ± a suitable and/or desired value, such as The aforementioned 130° ± 30°. In some non-limiting embodiments or examples, the piezoelectric layer 8 is, for example, a non-limiting LiNbO ₃ crystal, and the desired specific M4CE value may also be obtained from the cutting angle of Z-cut or X-cut.

In addition, the thickness of each of the aforementioned low-acoustic impedance layers and/or each of the high-acoustic impedance layers should not be limited, because the thickness of each of the low-acoustic impedance layers and/or each of the high-acoustic impedance layers can be ideally and/or Expected, without limitation, ≤1λ, ≤(1/2)λ, ≤(3/8)λ, ≤(1/4)λ, or ≤(1/8)λ, each with low and/or high acoustic impedance The thickness of the layer may be different or the same as the thickness of any other low and/or high acoustic impedance layer. Therefore, there is no limitation when the thickness of the low acoustic impedance layer is the same, the thickness of the high acoustic impedance layer is the same, or the thickness of the low acoustic impedance layer and the thickness of the high acoustic impedance layer are the same.

This result indicates that there may be little advantage in having one or more additional low acoustic impedance layers between the high acoustic impedance layer 106 and the device layer 12 or the substrate 16 or both.

Sixth UBAR Example: A stack-enabled flex mode ( Mode 4) comprising at least one low acoustic impedance layer and one high acoustic impedance layer, and optionally one device layer. Referring to FIG. 14 with continued reference to FIG. 11 , in some non-limiting implementations or examples, a sixth UBAR 2 example (shown in FIG. 14 ) is formed from alternating low and high acoustic impedance layer materials, which are formed from piezoelectric layers 8 (formed from LiNbO ₃ crystal, cutting angle is 130° (± 30° or ± 20° or ± 10°)) to device layer 12 may include: a first low acoustic impedance layer 100, a first high acoustic impedance layer 102. The second low acoustic impedance layer 104, the second high acoustic impedance layer 106, the third low acoustic impedance layer 108, the third high acoustic impedance layer 110, the fourth low acoustic impedance layer 112, the fourth high acoustic impedance layer Acoustic impedance layer 114 , fifth low acoustic impedance layer 116 , fifth high acoustic impedance layer 118 , sixth low acoustic impedance layer 120 , sixth high acoustic impedance layer 122 , seventh low acoustic impedance layer 124 , the seventh high acoustic impedance layer 126 , the eighth low acoustic impedance layer 128 , the eighth high acoustic impedance layer 130 and the ninth low acoustic impedance layer 132 .

In this example, the interdigitated conductive lines or elastic pieces 20 or 28 in the upper conductive layer 6 (as shown in FIGS. 4A and 4B ) have a finger spacing 38 of 1.2 µm, a λ value of 2.4 µm, and a piezoelectric layer thickness of ( 0.2)λ, the thickness of each low acoustic impedance layer is (1/16)λ and the thickness of the device layer 12 is 4λ.

To mold the sixth instance of UBAR 2 at several different cutting angles from 100° to 160° for the piezoelectric layer 8 , an exemplary electrical stimulation frequency sweep (eg, 1 GHz to 6.2 GHz) was performed on the sixth instance of UBARs 2 to The frequency response was confirmed, at different exemplary thicknesses of the high acoustic impedance layer, for example in the manner described above for the fourth UBAR2. In this example, for each piezoelectric layer 8 cutting angle and each frequency sweep, each high acoustic impedance layer has the same thickness. A graph, graph, or relationship of frequency vs. amplitude is confirmed for each frequency sweep.

In some non-limiting implementations or examples, the low acoustic impedance layers can be formed from silicon dioxide (SiO ₂ ), the high acoustic impedance layers can be formed from, for example, aluminum nitride (AlN), and the device layer 12 It can be formed from diamond or SiC and substrate 16 can be formed from silicon.

Using equation EQ2 and a graph, graph or relationship of the frequency response identified for the sixth UBAR 2 example, the ideal coupling efficiency M4CE for the mode 4 resonant frequency 88 of the sixth UBAR 2 example can be identified as: When the f _p2 and f _s2 values are equal to At 5.38 GHz and 5.09 GHz, M4CE = 13.287%, when the piezoelectric layer 8 has a 130° cutting angle of 130° and the thickness of each high acoustic impedance layer is (5/16)λ.

In some non-limiting implementations or examples, the thicknesses of the low acoustic impedance layers and/or the high acoustic impedance layers may be the same or different. In some non-limiting embodiments or examples, diamond, SiC, W, AlN, etc. can be used as materials for each high acoustic impedance layer.

Since M4CE values ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8%, or ≥ 10% are satisfactory, suitable and/or desired, the aforementioned M4CE values in this example should not be limiting . In addition, the thickness of each of the aforementioned low-acoustic impedance layers and/or each of the high-acoustic impedance layers should not be limited, as the thickness of each of the low-acoustic impedance layers and/or each of the high-acoustic impedance layers may be suitable and/or or desired, without limitation ≤1λ, ≤(1/2)λ, ≤(3/8)λ, ≤(1/4)λ or ≤(1/8)λ, each with low and/or high acoustic impedance The thickness of the resistive layer may be different (or the same) as the thickness of any other low and/or high acoustic resistive layer. Therefore, the thickness of the low acoustic impedance layer is the same, the thickness of the high acoustic impedance layer is the same, or the thickness of the low acoustic impedance layer and the thickness of the high acoustic impedance layer are not limited herein.

In one example, M4CE values ≥ 3%, ≥ 4%, ≥ 6%, ≥ 8%, or ≥ 10% can be achieved by adjusting the cutting angle of the piezoelectric layer 8 ± a suitable and/or desired value, such as The aforementioned 130° ± 30°. In some non-limiting embodiments or examples, the piezoelectric layer 8 is not limited, such as LiNbO ₃ crystal, and is cut at a specific angle of Z-cut or X-cut, and a specific desired M4CE value can also be obtained.

In some non-limiting implementations or examples, the molds of the aforementioned first to sixth examples of UBARs 2 are represented by computer simulations, and in some cases, in one or more practical examples.

In some non-limiting implementations or examples, it can be known from the first to sixth examples of UBARs 2 that the piezoelectric layer 8 formed from LiNbO ₃ and cut at an angle of 130° or approximately can obtain an ideal M4CE value. However, in some non-limiting embodiments or examples, the piezoelectric layer 8 formed from LiNbO ₃ and cut at an angle of 100° to 160° can also obtain ideal M4CE values; the piezoelectric layer 8 formed from LiNbO ₃ A more ideal M4CE value can be obtained by cutting at an angle of 110° to 150°; a further ideal M4CE value can be obtained by cutting the piezoelectric layer 8 formed from LiNbO ₃ at an angle of 120° to 140°. However, forming the piezoelectric layer ₈ from LiNbO3 and cutting at an angle of 130° results in the most desirable (highest) M4CE values.

In any of the UBAR examples described herein, the thickness of the piezoelectric layer, such as LiNbO ₃ , can be of any suitable and/or desired thickness, for example, in the flex mode example of Mode 4, the thickness is ≤ 0.5λ, ≤ 0.4λ, ≤0.3λ or ≤0.2λ.

In any of the UBAR examples described herein, the thickness of the piezoelectric layer, such as LiNbO ₃ , can be of any suitable and/or desired thickness, eg, in the shear mode example of Mode 3, the thickness is ≤ 2λ, ≤ 1.6 λ, ≤1.2λ or ≤0.8λ.

In any of the UBAR examples described herein, the thickness of the electrodes, such as Al, Mo, W, etc., can be any suitable and/or desired thickness, such as ≥0.010λ, ≥0.013λ, ≥0.016λ, ≥0.019 λ or ≥ 0.022λ.

For any of the UBAR examples described herein, the thickness of the device layers, such as diamond, SiC, AlN, etc., can be any suitable and/or desired thickness, such as ≥50 nm, ≥100 nm, ≥150 nm, or ≥ 200 nm.

For any of the UBAR examples described herein, the thickness of the low acoustic impedance layer may be suitable and/or desired thickness, eg, ≥0.05λ, ≥0.07λ, ≥0.09λ, ≥0.11λ, or ≥0.13λ .

In any of the UBAR examples described herein, the thickness of the high acoustic impedance layer may be suitable and/or desired thickness, eg, ≥0.05λ, ≥0.07λ, ≥0.09λ, ≥0.11λ, or ≥0.13λ .

In any of the UBAR examples described herein, the thickness of the temperature compensation layer can be a suitable and/or desired thickness, eg, ≤2λ, ≤1.5λ, ≤1.0λ, ≤0.5λ, or ≤0.3λ. Ideally, one or more or all of the outer surfaces of any of the UBAR examples described herein are protected by an optional passivation layer. The passivation layer can be a layer of dielectric material, such as AlN, SiN, SiO ₂ and the like.

The resonant frequency of any of the UBAR examples described herein may be > 0.1 GHz, > 0.5 GHz, > 1.0 GHz, > 1.5 GHz, or > 2.0 GHz.

The coupling efficiency of any of the UBAR examples described herein can be > 3%, > 4%, > 6%, > 8%, or > 10%.

Any of the UBAR examples described herein will resonate in _a mode that includes a bulk acoustic wave. Shallow bulk acoustic waves may include, but are not limited to, _S0 mode, extended mode, shear mode, A1 mode, flexural mode, etc., and Composite mode.

Further non-limiting embodiments or examples will be described in the following numbered examples. [Example]

Embodiment 1: A bulk acoustic wave resonator includes: a resonant body, which includes: a piezoelectric layer, the piezoelectric layer is a single crystal of LiNbO ₃ ; a device layer; and an upper conductive layer, which is located on the piezoelectric layer Above and on the other side of the piezoelectric layer is the device layer; wherein the entire surface of the device layer opposite to the piezoelectric layer is substantially used to mount the resonator body on the carrier and separate the resonator body.

Embodiment 2: The bulk acoustic wave resonator of Embodiment 1, wherein the single crystal of LiNbO ₃ can be cut at an angle of 130°±30°, ±20° or ±10°.

Embodiment 3: The bulk acoustic wave resonator as in Embodiment 1 or 2, wherein the single crystal of LiNbO ₃ can be cut at an angle of 0°±30°, ±20° or ±10°.

Embodiment 4: The BAW resonator according to any one of Embodiments 1 to 3, may include a resonant frequency of mode 3 or mode 4 ≥ 0.1 GHz, ≥ 0.5 GHz, ≥ 1.0 GHz, ≥ 1.5 GHz or ≥ 2.0 GHz .

Embodiment 5: The bulk acoustic wave resonator according to any one of Embodiments 1 to 4, which can include at least one of the following: the coupling efficiency of mode 3 resonance is ≥8%, ≥11%, ≥14%, ≥17 % or ≥20%; and the coupling efficiency of mode 4 resonance ≥3%, ≥4%, ≥6%, ≥8% or ≥10%.

Embodiment 6: The bulk acoustic wave resonator according to any one of Embodiments 1 to 5, wherein the single crystal thickness of LiNbO ₃ in mode 4 resonance can be ≤ 0.5λ, ≤ 0.4λ, ≤ 0.3λ or ≤ 0.2λ .

Embodiment 7: The bulk acoustic wave resonator according to any one of Embodiments 1 to 6, wherein the single crystal thickness of LiNbO ₃ in the mode 3 resonance can be ≤ 2λ, ≤ 1.6λ, ≤ 1.2λ or ≤ 0.8λ.

Embodiment 8: The bulk acoustic wave resonator according to any one of Embodiments 1 to 7, further comprising a conductive layer between the piezoelectric layer and the device layer, with a thickness of ≥ 0.010λ, ≥ 0.013λ, ≥ 0.016λ , ≥ 0.019λ, or ≥ 0.022λ.

Embodiment 9: The BAW resonator according to any one of Embodiments 1 to 8, wherein the thickness of the device layer can be ≥ 50 nm, ≥ 100 nm, ≥ 150 nm or ≥ 200 nm.

Embodiment 10: The bulk acoustic wave resonator according to any one of Embodiments 1 to 9, further comprising a low acoustic impedance material between the piezoelectric layer and the device layer, the acoustic impedance of the aforementioned low acoustic impedance material is between Between 10 ⁶ Pa-s/m ³ and 30 x 10 ⁶ Pa-s/m ³ , the thickness is ≥ 0.05λ, ≥ 0.07λ, ≥ 0.09λ, ≥ 0.11λ or ≥ 0.13λ.

Embodiment 11: The bulk acoustic wave resonator according to any one of Embodiments 1 to 10, further comprising a high acoustic impedance material between the piezoelectric layer and the device layer, wherein the acoustic impedance of the aforementioned high acoustic impedance material is between 10 ⁶ Pa-s/m ³ and 630 x 10 ⁶ Pa-s/m ³ with thicknesses ≥ 0.05λ, ≥ 0.07λ, ≥ 0.09λ, ≥ 0.11λ or ≥ 0.13λ.

Embodiment 12: The bulk acoustic wave resonator according to any one of Embodiments 1 to 11, further comprising a temperature compensation layer between the piezoelectric layer and the device layer, the temperature compensation layer comprising silicon and oxygen, and having a thickness of ≤ 2λ, ≤ 1.5λ, ≤ 1.0λ, ≤ 0.5λ, or ≤ 0.3λ.

Embodiment 13: The bulk acoustic wave resonator of any one of Embodiments 1 to 12 further comprises a passivation layer.

Embodiment 14: The BAW resonator according to any one of Embodiments 1 to 13, wherein the above-mentioned upper conductive layer may include at least one set of conductive elastic sheets with spaces. The finger spacing of the at least one group of conductive elastic sheets with spaces may be ≤ 70 μm, ≤ 20 μm, ≤ 10 μm, ≤ 6 μm or ≤ 4 μm.

Embodiment 15: The BAW resonator of any one of Embodiments 1 to 14, further comprising a plurality of alternating temperature compensation layers and high acoustic impedance layers between the piezoelectric layer and the device layer.

Embodiment 16: the bulk acoustic wave resonator according to any one of Embodiments 1 to 15, wherein the aforementioned device layer may further comprise the following: diamond; W; SiC; Ir, AlN, Al; Pt; Pd; Mo; Cr ; Ti; Ta; elements of group 3A or 4A on the periodic table; transition elements of group 1B, 2B, 3B, 4B, 5B, 6B, 7B or 8B on the periodic table; ceramics; glasses and polymers.

The object of the present invention has been described in detail based on what is presently considered to be the most ideal practical and non-limiting embodiment, example or form, but it should be understood that such details are only used for this purpose and the invention is not limited to the disclosed ideal and non-limiting embodiment, instance or form of. On the contrary, the description is intended to cover modifications and equivalent arrangements within the spirit and scope of its patent claims. For example: it should be understood that the present invention will, as far as possible, contemplate any or more ideal and non-limiting embodiments, examples, forms or techniques of the scope of the appended claims, which may be combined with one or more other ideal and non-limiting embodiments. Embodiments, examples, patterns, or technical combinations within the scope of the appended claims.

2: Bulk Acoustic Resonator (UBAR) 4: Resonator body 6: Upper conductive layer 8: Piezoelectric layer 10: Optional lower conductive layer 12: Device layer 14: Carrier 16: Substrate 18: Interdigital electrode 20, 24, 28: Shrapnel 22, 26: Back 27: Comb Electrodes 30: First Back 32: Second Back 33: Sheet electrode 34, 36: Connection structure 38: Finger Spacing 40, 44 Bottom metal layer 42, 46 metal layers 48, 58: Contact pads 50: Conductive vias 52, 60: conductor 54: Lateral conductor 56, 62: Tether Conductor 64, 66, 68, 70: Bottom 76: Tethered Structure 82, 84, 88: Resonance frequency 90, 92, 94: temperature compensation layer 96: Aluminum Nitride 100: The first low acoustic impedance layer 102: The first high acoustic impedance layer 104: Second low acoustic impedance layer 106: Second high acoustic impedance layer 108: Third low acoustic impedance layer 110: The third high acoustic impedance layer 112: Fourth low acoustic impedance layer 114: Fourth high acoustic impedance layer 116: Fifth low acoustic impedance layer 118: Fifth high acoustic impedance layer 120: Sixth low acoustic impedance layer 122: sixth high acoustic impedance layer 124: Seventh low acoustic impedance layer 126: Seventh high acoustic impedance layer 128: Eighth low acoustic impedance layer 130: Eighth high acoustic impedance layer 132: Ninth Low Sound Impedance Layer

The present invention will be described by the following description in conjunction with the drawings, so as to make the above and other purposes and technical features of the invention more apparent.

[FIG. 1] is a side view of an unsuspended BAW resonator according to an ideal and non-limiting implementation form or example of the principles of the present invention (eg, used herein to illustrate the first example of an unsuspended BAW resonator). and the second example). [FIG. 2] is a side view of an unsuspended BAW resonator according to an ideal and non-limiting implementation or example of the principles of the present invention. [FIG. 3] is a side view of an unsuspended BAW resonator according to an ideal and non-limiting implementation or example of the principles of the present invention. [FIG. 4A] is an isolated plan view of an interdigitated electrode according to an ideal and non-limiting embodiment or example of the principles of the present invention, which can be used as an upper conductive layer, an optional lower conductive layer of an unsuspended bulk acoustic wave resonator. layer or both. [FIG. 4B] is an isolated plan view of a comb electrode according to an ideal and non-limiting implementation form or example of the principles of the present invention, which can be used as an upper conductive layer, an optional lower conductive layer of an unsuspended bulk acoustic wave resonator. layer or both. [FIG. 4C] is an isolated plan view of a sheet electrode according to an ideal and non-limiting embodiment or example of the principles of the present invention, which can be used as an upper conductive layer, an optional lower conductive layer of an unsuspended bulk acoustic wave resonator. layer or both. [Figs. 5A-5B] are ideal and non-limiting implementations or examples of Figs. 1 to 3, and are cross-sectional views along lines A-A and B-B. [Figs. 6A-6B] are ideal and non-limiting implementations or examples of Figs. 1 to 3, and are cross-sectional views along lines A-A and B-B. [Figs. 7A-7B] are ideal and non-limiting implementations or examples of Figs. 1 to 3, and are cross-sectional views along lines A-A and B-B. [FIG. 7C] is a side view of the unsuspended BAW resonator of an ideal and non-limiting implementation or example of FIGS. 7A-7B, with the material on the first and second connection structures and the tether conductors on both sides removed. [Figs. 8A-8B] are ideal and non-limiting implementations or examples of Figs. 1 to 3, and are cross-sectional views along lines A-A and B-B. [FIG. 8C] is a side view of the unsuspended BAW resonator of an ideal and non-limiting implementation or example of FIGS. 8A-8B with the material on the first and second connecting structures and the tether conductors on both sides removed. [FIG. 8D] is a side view of the unsuspended BAW resonator of an ideal and non-limiting implementation or example of FIGS. 8A-8B with the material on the first and second connecting structures and the tether conductors on both sides removed. [Figs. 9A-9B] are ideal and non-limiting implementations or examples of Figs. 1 to 3, and are cross-sectional views along lines A-A and B-B. [FIG. 9C] is a side view of the unsuspended BAW resonator of an ideal and non-limiting implementation or example of FIGS. 9A-9B with the material on the first and second connecting structures and the tether conductors on both sides removed. [FIG. 9D] is a side view of the unsuspended BAW resonator of an ideal and non-limiting implementation or example of FIGS. 9A-9B with the material on the first and second connection structures and the tether conductors on both sides removed. [Fig. 10] is a graph of frequency versus decibel of a resonator body. The resonator body has a lower conductive layer in the form of sheet electrodes and an upper conductive layer in the form of sparse electrodes, and the finger spacing is 1.8 μm. [FIG. 11] is an exemplary graph of frequency versus normalized vibration, especially the resonant frequencies of mode 3 and mode 4, which can be used to illustrate the first to sixth examples of unsuspended bulk acoustic resonators described in this specification frequency response. [FIG. 12] is a side view of an unsuspended BAW resonator according to an ideal and non-limiting implementation or example of the principles of the present invention (eg, a third embodiment of an unsuspended BAW resonator is used here to illustrate the invention). example). [FIG. 13] is a side view of an unsuspended BAW resonator according to an ideal and non-limiting implementation or example of the principles of the present invention (eg, the fourth method used to illustrate the and fifth example). [FIG. 14] is a side view of an unsuspended BAW resonator according to an ideal and non-limiting implementation form or example of the principles of the present invention (for example, the sixth method used to illustrate the unsuspended BAW resonator herein. example).

2: Bulk Acoustic Resonator (UBAR)

6: Upper conductive layer

8: Piezoelectric layer

10: Optional lower conductive layer

12: Device layer

14: Carrier

34, 36: Connection structure

90, 92: temperature compensation layer

96: Aluminum Nitride

Claims (18)

A bulk acoustic wave resonator is characterized by comprising: a resonator body, comprising: a piezoelectric layer, the piezoelectric layer is a single crystal of LiNbO ₃ ; a device layer is located below the piezoelectric layer; at least one pair of A temperature compensation layer and a high acoustic impedance layer are located between the piezoelectric layer and the device layer; and an upper conductive layer is located above the piezoelectric layer and the other side of the piezoelectric layer is the piezoelectric layer. The device layer; wherein the entire surface of the device layer opposite to the piezoelectric layer is substantially used to mount the resonator body on the carrier and separate the resonator body. The bulk acoustic wave resonator according to claim 1, wherein the single crystal of LiNbO ₃ has a cutting angle and a thickness. The bulk acoustic wave resonator as set forth in claim 2, wherein the single crystal of the aforementioned LiNbO ₃ is 130°±30°, 130°±20°, 130°±10°, 0°±30° or 0°±20° Angled cut. The bulk acoustic wave resonator according to claim 2, wherein the aforementioned angle and the aforementioned thickness are favorable for a predetermined coupling efficiency of a mode 3 resonance and a mode 4 resonance. The bulk acoustic wave resonator according to claim 4, wherein the single crystal of LiNbO ₃ is cut at an angle of 0°±10°. The bulk acoustic wave resonator as claimed in claim 5, comprising the aforementioned mode 3 resonance or the aforementioned mode 4 resonance with a resonance frequency ≥ 0.1 GHz. The bulk acoustic wave resonator as claimed in claim 4, comprising at least one of the following: the aforementioned mode 3 resonance with a predetermined coupling efficiency ≥8%; and The aforementioned mode 4 resonance with a predetermined coupling efficiency ≥ 3%. The bulk acoustic wave resonator as claimed in claim 7, wherein, in the aforementioned mode ₄ resonance, the single crystal thickness of the aforementioned LiNbO ≤ 0.5λ, wherein the λ value is based on the size of the pattern or feature defined by the aforementioned upper conductive layer, or Based on the aforementioned single crystal thickness of LiNbO ₃ . The bulk acoustic wave resonator according to claim 7, wherein, in the above-mentioned mode ₃ resonance, the single-crystal thickness of the above-mentioned LiNbO ≤ 2λ, wherein the λ value is based on the size of the pattern or feature defined by the above-mentioned upper conductive layer, or based on The single crystal thickness of the aforementioned LiNbO ₃ . The bulk acoustic wave resonator as claimed in claim 1, further comprising a lower conductive layer with a thickness ≥ 0.010λ located between the piezoelectric layer and the device layer, wherein the λ value is based on patterns or features defined by the upper conductive layer size, or based on the single crystal thickness of the aforementioned LiNbO ₃ . The bulk acoustic wave resonator as claimed in claim 1, wherein the thickness of the aforementioned device layer is ≥ 50 nm. The bulk acoustic wave resonator as claimed in claim 1, further comprising a layer of low acoustic impedance material located between the piezoelectric layer and the device layer, which has a value between 10 ⁶ Pa-s/m ³ and 30 x 10 ⁶ Pa Acoustic impedance and thickness ≥ 0.05λ between -s/m ³ , where the λ value is based on the size of the pattern or feature defined by the aforementioned upper conductive layer, or based on the aforementioned single crystal thickness of LiNbO ₃ . The bulk acoustic wave resonator according to claim 1, wherein the high acoustic impedance layer in at least one pair between the piezoelectric layer and the device layer has a value of 10 ⁶ Pa-s/m Acoustic impedance and thickness ≥ 0.05λ between ³ and 630 x 10 ⁶ Pa-s/m ³ , where the λ value is based on the size of the pattern or feature defined by the aforementioned upper conductive layer, or based on the aforementioned single crystal thickness of LiNbO ₃ . The bulk acoustic wave resonator according to claim 1, wherein the temperature compensation layer in at least one pair between the piezoelectric layer and the device layer comprises silicon and oxygen, and has a thickness ≤ 2λ, where λ Values are based on the size of the pattern or feature defined by the aforementioned upper conductive layer, or based on the aforementioned single crystal thickness of LiNbO ₃ . The bulk acoustic wave resonator as claimed in claim 1, further comprising a passivation layer. The bulk acoustic wave resonator according to claim 1, wherein the upper conductive layer includes at least one set of conductive elastic sheets with spaces. The bulk acoustic wave resonator according to claim 1, wherein the at least one pair of the temperature compensation layer and the high acoustic impedance layer located between the piezoelectric layer and the device layer includes a plurality of alternating temperature compensation layers and high acoustic impedance layer. The bulk acoustic wave resonator according to claim 1, wherein the device layer comprises at least one of the following: diamond; W; SiC; Ir, AlN, Al, Pt, Pd, Mo, Cr, Ti, Ta; periodic table Elements of groups 3A or 4A in the periodic table; transition elements of groups 1B, 2B, 3B, 4B, 5B, 6B, 7B or 8B in the periodic table; ceramics; glasses and polymers.

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