JP2020202564A - Electrode-defined unsuspended acoustic resonator - Google Patents

Abstract

To provide a resonator which can be generally operated in a bulk acoustic mode and can be operated preferentially in a lateral resonance mode.SOLUTION: An unsuspended bulk acoustic resonator 2 includes a resonator body 4. The resonator body 4 includes a piezoelectric layer 8 which is LiNbO 3 single crystal, an element layer 12, and an upper conductive layer 6 on the piezoelectric layer 8 opposite the element layer 12, and substantially all of the surface of the element layer 12 opposite the piezoelectric layer 8 is for mounting the resonator body 4 on a carrier 14 which is not a part of the resonator body 4.SELECTED DRAWING: Figure 1

Description

Field of Invention The present invention relates to bulk acoustic resonators, and more specifically, can be used to supply an electrical signal to the resonator body and, optionally, one or more conductive layers of the resonator body. It relates to a bulk acoustic resonator having one or more connecting structures.

Description of related technologies Radio frequency communication has evolved from the "1G" system of the 1980s to the "2G" system of the 1990s, the "3G" system of the early 2000s, and the current "4G" system standardized in 2012. I've done it. In current RF communications, RF signals are filtered using surface acoustic wave (SAW) filters or bulk surface acoustic wave (BAW) filters.

Thin-film bulk acoustic resonators (FBARs) and solid-mounted resonators (SMRs) are relatively compatible with current 4G RF communications compared to SAW filter elements. Two types of BAW filters that are piezoelectric driven microelectromechanical system (MEMS) elements that allow resonance at high frequencies with relatively low insertion loss. These BAW acoustic resonators, for example, include a piezoelectric stack containing a thin film of piezoelectric material sandwiched between a thin film top electrode and a thin film bottom electrode. The resonant frequency of such a piezoelectric stack is either thickness-based or depends on the thickness of the thin film of the piezoelectric stack. The resonance frequency increases as the thickness of the piezoelectric stack thin film decreases. The film thickness of the resonator is crucial and must be precisely controlled for the desired resonant frequency. It is difficult to adjust different regions of the piezoelectric stack to achieve a high level of thickness uniformity in order to achieve reasonable yields in the FBAR and SMR manufacturing processes for targeted or specified RF frequencies. Yes, it takes time.

The 5G RF communication systems being developed will eventually replace the previously mentioned lower performance older generation communication systems operating at RF frequencies between hundreds of MHz and 1.8 GHz. 5G systems instead operate at much higher RF frequencies, eg, 3-6 GHz (less than 6 GHz), and in some cases up to about 100 GHz.

Due to this increase in frequency, the film thickness of FBAR and SMR based RF filters for 5G applications would have to be reduced to increase the resonant frequency, which is currently the highest level BAW acoustic resonator. Is one of the challenges facing. Reducing the piezoelectric film thickness means that the distance between the top and bottom electrodes of the piezoelectric stack is also reduced, which results in an increase in electrical capacity. This increase in electrical capacity results in a higher feedthrough of the RF signal and reduces the signal-to-noise ratio, which is not desirable. The optimum piezoelectric coupling efficiency of the piezoelectric stack (including the top electrode, the bottom electrode, and the piezoelectric layer sandwiched between the top electrode and the bottom electrode) is the thickness of the piezoelectric layer, the thickness of the top electrode, and the thickness of the bottom electrode. , Can result from the proper combination with the arrangement and orientation of the piezoelectric crystals. Reducing the piezoelectric film thickness to achieve desirablely high RF frequency operation for 5G communications may not make it possible to achieve optimum piezoelectric coupling efficiency, resulting in higher insertion loss and higher kinetic impedance. Become. The thickness of either the top electrode, the bottom electrode, or both may need to be reduced. Reducing the electrode thickness results in an increase in electrical resistivity, which leads to another undesired constraint: higher insertion loss.

Furthermore, the product of the frequency of the FBAR and SMR elements and the quality factor (or Q) is typically constant, which means that an increase in resonance frequency results in a decrease in Q. The decrease in Q is not desirable, especially assuming that the highest levels of Q in FBAR and SMR are approaching the theoretical limit at frequencies below 2.45 GHz. Therefore, doubling the frequency results in a reduction in the Q value, which is not desirable for making RF elements such as RF filters, RF resonators, RF switches, RF oscillators.

Generally, a resonator body capable of operating in bulk acoustic mode and preferentially in lateral resonance mode is provided. The bottom surface of the resonator body can be mounted or coupled to a mounting substrate or carrier, while still allowing the resonator body to be used as an RF filter, RF resonator, RF switch, RF oscillator, and the like.

Bulk acoustic resonators are also provided that include a resonator body and one or more connection structures that allow electrical signals to be delivered to one or more conductive layers of the resonator body. In one preferred and non-limiting embodiment or example, one or more connecting structures can be integrated with and / or formed from a layer of the same material as the resonator body. As a result, the bulk acoustic resonator can be an integral part. The bottom of the integral bulk acoustic resonator can be mounted or coupled to a mounting substrate or carrier, while still allowing the resonator body to be used as an RF filter, RF resonator, RF switch, RF oscillator, etc. be able to.

These and other features of the invention will become more apparent from the following description with reference to the accompanying drawings.

Side views of one preferred and non-limiting embodiment or example of a non-suspended bulk acoustic resonator according to the principles of the present invention (eg, first and second examples of a non-suspended bulk acoustic resonator herein). (Used to explain). FIG. 6 is a side view of one preferred and non-limiting embodiment or example of a non-suspended bulk acoustic resonator according to the principles of the present invention. FIG. 6 is a side view of one preferred and non-limiting embodiment or example of a non-suspended bulk acoustic resonator according to the principles of the present invention. One preferred and non-limiting embodiment in the form of alternating mating electrodes that can be used as a top conductive layer of a non-suspended bulk acoustic resonator, an optional bottom conductive layer, or both, according to the principles of the invention. It is a single plan view of an example. One preferred and non-limiting embodiment or example in the form of a comb tooth electrode that can be used as a top conductive layer of a non-suspended bulk acoustic resonator, an optional bottom conductive layer, or both, according to the principles of the invention. It is a single plan view of. Of one preferred and non-limiting embodiment or example in the form of a sheet electrode that can be used as a top conductive layer of a non-suspended bulk acoustic resonator, an optional bottom conductive layer, or both, according to the principles of the invention. It is a single plan view. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines AA in each of FIGS. 1-3. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines BB in each of FIGS. 1-3. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines AA in each of FIGS. 1-3. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines BB in each of FIGS. 1-3. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines AA in each of FIGS. 1-3. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines BB in each of FIGS. 1-3. One preferred and non-limiting of non-suspended bulk acoustic resonators according to the principles of the invention, with the materials of the first and second connecting structures and on both sides of the tether conductor removed as shown in FIGS. 7A-7B. It is a side view of a typical embodiment or example. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines AA in each of FIGS. 1-3. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines BB in each of FIGS. 1-3. One preferred and non-limiting of non-suspended bulk acoustic resonators according to the principles of the present invention, in which the materials of the first and second connection structures and on both sides of the tether conductor have been removed as shown in FIGS. 8A-8B. It is a side view of a typical embodiment or example. One preferred and non-limiting of non-suspended bulk acoustic resonators according to the principles of the present invention, in which the materials of the first and second connection structures and on both sides of the tether conductor have been removed as shown in FIGS. 8A-8B. It is a side view of a typical embodiment or example. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines AA in each of FIGS. 1-3. FIG. 3 is a cross-sectional view of preferred and non-limiting embodiments or examples along lines BB in each of FIGS. 1-3. One preferred and non-limiting of non-suspended bulk acoustic resonators according to the principles of the present invention, in which the materials of the first and second connection structures and on both sides of the tether conductor have been removed as shown in FIGS. 9A-9B. It is a side view of a typical embodiment or example. One preferred and non-limiting of non-suspended bulk acoustic resonators according to the principles of the present invention, in which the materials of the first and second connection structures and on both sides of the tether conductor have been removed as shown in FIGS. 9A-9B. It is a side view of a typical embodiment or example. FIG. 5 is a frequency vs. dB plot of a resonator body having a bottom conductive layer in the form of a thin plate electrode and a top conductive layer in the form of a comb tooth electrode with a finger pitch of 1.8 μm. It can be used to describe the frequency response of the first to sixth examples of non-suspended bulk acoustic resonators described herein, in particular frequency vs. normalization indicating mode 3 and mode 4 resonant frequencies. It is an exemplary plot of the amplitudes made. Side views of one preferred and non-limiting embodiment or example of a non-suspended bulk acoustic resonator according to the principles of the present invention (eg, the present specification describes a third example of a non-suspended bulk acoustic resonator. (Used for). Side views of one preferred and non-limiting embodiment or example of a non-suspended bulk acoustic resonator according to the principles of the present invention (eg, in the present specification, fourth and fifth examples of a non-suspended bulk acoustic resonator). (Used to explain). Side views of one preferred and non-limiting embodiment or example of a non-suspended bulk acoustic resonator according to the principles of the present invention (eg, the present specification describes a sixth example of a non-suspended bulk acoustic resonator. (Used for).

For the detailed description below, it should be understood that the present invention may take a series of various alternative variants and steps, except as explicitly stated in the opposite direction. It should also be understood that the specific devices and methods described in the patent specification below are merely exemplary embodiments, examples, or embodiments of the present invention. Further, in preferred and non-limiting embodiments, examples, or embodiments, the quantity of elements used in the present specification and claims, except in any working example, or unless otherwise indicated. All numbers represented are to be understood to be modified by the term "about" in all cases. Therefore, unless otherwise specified, the numerical parameters described in the following patent specification and the appended claims are approximate values that may vary depending on the desired properties obtained by the present invention. .. Therefore, each numerical parameter should be interpreted at least in light of the number of effective digits reported and by applying conventional rounding techniques.

Despite the fact that the numerical ranges and parameters that describe the broad range of the invention are approximations, the numerical values described in the specific examples are reported as accurately as possible. However, any numerical value essentially contains some error that inevitably arises from the standard deviation found in their respective test measurements.

It should also be understood that any numerical range listed herein is intended to include all subranges contained therein. For example, the range "1 to 10" covers between (and includes) the listed minimum values of 1 and the listed maximum values of 10, that is, a minimum value of 1 or more and a maximum value of 10 or less. It is intended to include the entire subrange that it has.

It should also be understood that the specific elements and processes shown in the accompanying drawings and described in the patent specification below are merely exemplary embodiments, examples, or embodiments of the present invention. Therefore, the specific dimensions and other physical properties associated with an embodiment, example, or aspect disclosed herein are not considered to be limiting. Certain preferred and non-limiting embodiments, examples, or embodiments of the present invention will be described with reference to the accompanying figures in which the same reference numbers correspond to the same or functionally equivalent elements.

In the present application, the use of the singular may include plural, and the plural includes the singular, unless otherwise stated. Further, in this application, unless otherwise stated, the use of "or (or)" may be explicitly used in certain cases, even if "and / or (and / or)" is available. It means "and / or (and / or)". Further, in the present application, the use of "one (a)" or "one (an)" means "at least one" unless otherwise stated.

For the following explanation, "end", "upper", "lower", "right", "left", "vertical (vertical)" The terms "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal" and their derivatives are drawings. It relates to an example in which it is placed in the correct position in the figure of. However, it should be understood that the examples can take a series of various alternative variants and steps, unless explicitly stated in the opposite direction. It should also be understood that the specific examples shown in the accompanying drawings and described in the patent specification below are merely exemplary examples or embodiments of the present invention. Therefore, the specific examples or embodiments disclosed herein shall not be construed as limiting.

With reference to FIG. 1, in one preferred and non-limiting embodiment or example, an unsuspended bulk acoustic resonator (UBAR) according to the principles of the present invention, which may be operational in bulk acoustic mode. 2 may include a resonator body 4 from top to bottom that can include a stack of layers comprising a top conductive layer 6, a piezoelectric layer 8, an optional bottom conductive layer 10, and an element layer 12. it can. In the example shown in FIG. 1, in UBAR2, the bottom surface of the element layer 12 can be mounted, for example, can be mounted directly on the mounting board or the carrier 14.

With reference to FIG. 2 and continuing with reference to FIG. 1, in one preferred and non-limiting embodiment or example, at least the resonator body 4 of FIG. 2 is optional between the element layer 12 and the carrier 14. Another example of UBAR2 according to the principles of the present invention, with the exception that the substrate 16 can be included, can be similar to UBAR2 shown in FIG. In the example, the bottom surface of the element layer 12 can be mounted, for example, can be mounted directly on the top surface of the substrate 16, and the bottom surface of the substrate 16 can be mounted, for example, directly mounted on the carrier 14. be able to.

With reference to FIG. 3 and subsequently with reference to FIGS. 1 and 2, in one preferred and non-limiting embodiment or example, at least the resonator body 4 of FIG. 3 is an element layer 12 and a piezoelectric layer 8 or optionally. When the bottom conductive layer 10 is provided, the optional second substrate 16-1 and / or the second substrate 16-1 and the piezoelectric layer 8 or the optional bottom conductive layer 10 are provided between them. Another example of UBAR2 according to the principles of the present invention can be similar to UBAR2 shown in FIG. 2, except that an optional second element layer 12-1 can be included in between. In one preferred and non-limiting embodiment or example, the resonator body 4 of FIG. 3 is one or more additional element layers 12 (specifically, when considered appropriate and / or desirable). It is envisioned that (not shown) and / or one or more additional substrates 16 (not specifically shown) can be further included. An example of a resonator body 4 having several element layers 12 and a substrate 16 is the first element in an exemplary order from the piezoelectric layer 8 or the optional bottom conductive layer 10 to the carrier 14. A layer, a first substrate, a second element layer, a second substrate, a third element layer, a third substrate ,. .. .. And so on. In one preferred and non-limiting embodiment or example in which the resonator body 4 can include a plurality of element layers 12 and / or a plurality of substrates 16, each element layer 12 is made of the same or different materials. Each substrate 16 can be made of the same or different materials. In one preferred and non-limiting embodiment or example, the number of element layers 12 and the number of substrates 16 can vary. In the example, when the piezoelectric layer 8 or the bottom conductive layer 10 of the option is provided, and in the exemplary order from the carrier 14 to the carrier 14, the resonator body 4 includes the element layer 12-1, the substrate 16-1, and the resonator. The element layer 12 as the bottommost layer of the main body 4 can be included. Examples of materials that can be used to form each element layer 12 and each substrate 16 will be described below.

In one preferred and non-limiting embodiment or example, as shown in FIGS. 1-3, one or more optional temperature compensating layers 90, 92, and 94 are placed on the top surface of the top surface conductive layer 6. , When the piezoelectric layer 8 or the optional bottom conductive layer 10 is provided, and / or when the element layer 12 (or 12-1) and the substrate 16 (or 16-1) are provided between the piezoelectric layer 8 or the element layer 12. It can be provided between them. Each temperature compensation layer can contain at least one of silicon and oxygen. In an example, each temperature compensating layer can contain silicon dioxide or a silicon element and / or an oxygen element. When one or more optional temperature compensation layers 90, 92, and 94 are provided, the change in resonance frequency of each resonator body 4 example shown in FIGS. 1 to 3 due to heat generated during use is observed. It can help you avoid it.

In plan view, each resonator body 4 and / or UBAR 2 described herein can have a square or rectangle. However, a resonator body 4 and / or UBAR 2 having other shapes is envisioned.

With reference to FIGS. 4A-4C and subsequently with all previous drawings, in one preferred and non-limiting embodiment or example, one or both of the conductive layer 6 and the optional conductive layer 10 may be the rear surface 22. It can be in the form of an alternating fitting electrode 18 (FIG. 4A) that can include the conductive wire or finger 20 supported by and alternately fitted with the conductive wire or finger 24 and supported by the rear surface 26. In one preferred and non-limiting embodiment or example, one or both of the conductive layer 6 and the optional conductive layer 10 may include a conductive wire or finger 28 extending from a first rear surface 30. It can be in the form of 27 (FIG. 4B). The end of the conductive wire or finger 28 opposite to the first rear surface 30 can be connected to an optional second rear surface 32 (shown by a virtual line in FIG. 4B). In one preferred and non-limiting embodiment or example, one or both of the conductive layer 6 and the optional conductive layer 10 can be in the form of a conductive sheet electrode 33 (FIG. 4C). Each line or finger 20, 24 and 28 is shown as a straight line. In the example, each wire or finger 20, 24 and 28 may be a curved wire or finger, a swirl or finger, or any other suitable and / or desired shape.

In one preferred and non-limiting embodiment or example, the top conductive layer 6 can be in the form of an alternating fitting electrode 18, a comb tooth electrode 27, or a sheet electrode 33. Independent of the shape of the top conductive layer 6, the optional bottom conductive layer 10 can be in the form of an alternating fitting electrode 18, a comb tooth electrode 27, or a thin plate electrode 33, if provided. Below, and for illustration purposes only, in one preferred and non-limiting embodiment or example, the top conductive layer 6 of a comb tooth electrode 27 comprising a first rear surface 30 and an optional second rear surface 32. It will be described as having a shape, and the optional bottom conductive layer 10 will be described as having a shape of a thin plate electrode 33. However, in combination with any one of the optional bottom conductive layer 10 with alternating fitting electrodes 18, comb tooth electrodes 27, or thin plate electrodes 33, alternating fitting electrodes 18 with respect to the top conductive layer 6, or comb teeth. This shall not be construed in a limited sense as the use of any one of the electrode 27, or the thin plate electrode 33, is envisioned.

In one preferred and non-limiting embodiment or example, if an optional bottom conductive layer 10 is provided, at least the top conductive layer 6 in the form of alternating mating electrodes 18 or comb tooth electrodes 27, regardless of its shape. The resonant frequency of the example of each resonator body 4 having the above can be adjusted or selected in a manner well known in the art by appropriate selection of finger pitch 38 (see, eg, FIGS. 4A-4B). , Finger pitch 38 = width of finger + gap between fingers (between adjacent fingers). In examples where each resonator body 4 example resonates primarily in transverse mode with respect to thickness mode, but not all, the resonance frequency of the resonator body 4 reduces the finger pitch 38. It can be increased by making it. In an example where each resonator body 4 example resonates primarily in thickness mode relative to transverse mode, but not all, the resonance frequency of the resonator body 4 increases the finger pitch 38. It can be reduced by making it.

In one preferred and non-limiting embodiment or example, each example of the cavity body 4 resonates in thickness mode, transverse mode, or composite or composite mode, which is a combination of thickness mode and transverse mode. Can be done. In the thickness mode resonance, the acoustic wave resonates in the direction of the thickness of the piezoelectric layer 8, and the resonance frequency is the thickness of the piezoelectric layer 8 and the top conductive layer 6 and the bottom conductive layer 10 of arbitrary selection are provided. If based on the thickness with it. When the piezoelectric layer 8 and the optional bottom conductive layer 10 are provided, the combination of the piezoelectric layer 8 and the top conductive layer 6 can be referred to as a piezoelectric stack. The acoustic velocity that determines the resonant frequency of each resonator body 4 example described herein is the synthetic acoustic velocity of the piezoelectric stack. In the example, the resonance frequency f, the composite acoustic velocity V _a can be calculated by dividing by 2 times the thickness τ of the piezoelectric stack.

The transverse mode resonance, the acoustic waves resonate in the transverse direction of the piezoelectric layer 8 (x or y-direction), the resonant frequency, by dividing the synthetic acoustic velocity V _a of the piezoelectric stack at twice the finger pitch 38, that can be obtained by f _{= V} a / 2 (finger pitch). When the finger pitch is reduced from a large pitch size δ _L to a small pitch size δ _S , the frequency increase rate and PFI _Calculated can be calculated by the following equation in the example.
PFI _Calculated = (δ _{L −} δ _S ) / δ _S
In the example, when the finger pitch 38 is reduced from 2.2 μm to 1.8 μm, the PFI _Calculated in transverse mode is 22.2%. In another example, when the finger pitch 38 is reduced from 1.8 μm to 1.4 μm, the PFI _Calculated in transverse mode is 28.5%.

The composite mode resonance can include a thickness mode resonance portion and a transverse mode resonance portion. The portion of the transverse mode resonance L in the composite mode resonance is the actual or measured frequency increase rate calculated by PFI _Measured by changing the finger pitch 38 from a large pitch size δ _L to a small pitch size δ _S. It can be defined as a ratio to PFI _Calculated . The value of the transverse mode resonance L can be greater than 100% if there are one or more uncontrolled or unpredictable variations. In the example, the resonator body 4 can resonate in thickness mode, transverse mode, or composite mode. In the example of synthetic mode resonance, the portion of the transverse mode resonance L can be 20% or more. In another example of synthetic mode resonance, the portion of transverse mode resonance L can be 30% or more. In another example of synthetic mode resonance, the portion of transverse mode resonance L can be 40% or more.

In one preferred and non-limiting embodiment or example, the top conductive layer 6 in the form of an optional bottom conductive layer 10 in the form of a thin plate electrode 33 and a comb tooth electrode 27 with a finger pitch 38 of 2.2 μm. The resonator body 4 having the above can resonate in the combined mode using the mode resonance frequency of mode 1 resonance frequency = 1.34 GHz, mode 2 resonance frequency = 2.03 GHz, and mode 4 resonance frequency = 2.82 GHz. it can.

In the example, the resonator main body 4 having the bottom conductive layer 10 arbitrarily selected in the form of a thin plate electrode 33 and the top conductive layer 6 in the form of a comb tooth electrode 27 having a finger pitch 38 of 1.8 μm is a resonator. The main body 4 can resonate in a composite mode using a mode resonance frequency of 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 rate of the transverse mode resonance L of the combined mode resonances can be L mode 1 = 53%, L mode 2 = 78%, and L mode 4 = 27%, respectively. See also FIG. 10, which is a plot of the frequency vs. dB of the resonator body 4 of this example. In FIG. 10, each of the peaks 82, 84 and 88 is the response of the resonator body 4 at mode 1 resonant frequency = 1.49 GHz, mode 2 resonant frequency = 2.38 GHz, and mode 4 resonant frequency = 3.05 GHz, respectively. Represents.

In an example, the mode 1 resonant frequency may also be known or associated with the surface acoustic wave (SAW), or as an alternative, and the mode 2 resonant frequency may also be or as an alternative. As known as or associated with S ₀ (or extended) mode, the mode 4 resonant frequency is also known or, as an alternative, as A ₁ (or bending) mode, or associated with it. It may be. In addition, the mode 3 resonant frequency (discussed below) may also be known or associated with the shear mode, or as an alternative. SAW, S ₀ mode, extension mode, A ₁ mode, shear mode, and the bending mode are well known in the art and will not be described further herein.

In the example, the resonator main body 4 having the bottom conductive layer 10 arbitrarily selected in the form of the thin plate electrode 33 and the top conductive layer 6 in the form of the comb tooth electrode 27 having a finger pitch 38 of 1.4 μm is a resonator. The main body 4 can have a mode resonance frequency of mode 1 resonance frequency = 1.79 GHz, mode 2 resonance frequency = 2.88 GHz, and mode 4 resonance frequency = 3.36 GHz. In the resonator body 4 of this example, the ratio of the transverse mode resonance L in the combined mode resonance can be L mode 1 = 70%, L mode 2 = 74%, and L mode 4 = 35%.

In an example, the above description of the resonator body 4 resonating in thickness mode, transverse mode, or composite mode is combined with one or more connection structures 34 and 36 described in more detail below. It may also be applicable to the examples of each UBAR 2 shown in FIGS. 1 to 3, which can include the resonator body 4.

Continuing with reference to FIGS. 1-3, in one preferred and non-limiting embodiment or example, the bottom layer of each resonator body 4 shown in FIGS. 1-3 is any suitable and / or desirable. It can be mounted directly on the carrier 14 using mounting techniques such as eutectic mounting, bonding and the like. In the present specification, "mounted directory", "mounting ... directory" and similar terms are positioned close to the carrier 14, and in the example. , Mounted, mounted, etc. in any suitable and / or desired manner and / or in examples, bonded to the carrier 14 by any suitable and / or desired means such as eutectic bonding, conductive bonding, non-conductive bonding. , It shall be understood as the bottommost layer of each resonator main body 4 shown in FIGS. 1 to 3. In one preferred and non-limiting embodiment or example, the carrier 14 can be the surface of a package, such as a conventional integrated circuit (IC) package. After the bottom layer of the resonator body 4 is mounted on the surface of the package, the resonator body 4 and, more generally, UBAR2 are sealed in the package in a manner well known in the art. The resonator body 4 and, more generally, the UBAR 2 can be protected against external environmental conditions. In the example, for example, in order to implement UBAR, Japanese NTK Ceramic Co., Ltd. , Ltd. It is assumed that packages such as conventional ceramic IC packages commercially available from Japan will be used. However, this is not construed in a limited sense as it is assumed that the resonator body 4 and / or UBAR2 can be implemented in any suitable and / or desired package currently known or subsequently developed. It shall be.

In another example, the carrier 14 can be, for example, the surface of a substrate such as one ceramic, one conventional printed circuit board material. The description of the substrate example herein in which the bottom layer of each resonator body 4 and / or UBAR 2 shown in FIGS. 1-3 can be mounted is for illustration purposes only and is not construed in a limited sense. It shall be. Rather, the carrier 14 is compatible with the material forming the bottom layer of each resonator body 4 and / or UBAR2 shown in FIGS. 1-3 and the resonator body 4 and / or in a manner well known in the art. It can be made of any suitable and / or desired material that allows the use of UBAR2. The carrier 14 can have any shape suitable and / or desirable by those skilled in the art. Therefore, any description of the mounting board or carrier 14 herein is not to be construed in a limited sense.

Continuing with reference to FIGS. 1-3, in one preferred and non-limiting embodiment or example, each UBAR 2 is provided with a top conductive layer 6 of the resonator body 4 and an optional bottom conductive layer 10. It may include one or more optional connection structures 34 and / or 36 that facilitate the application of electrical signals to it. However, in one preferred and non-limiting embodiment or example, an electrical signal can be applied directly to the top conductive layer 6 of the resonator body 4 and the optional bottom conductive layer 10 provided. Alternatively, the plurality of optional connection structures 34 and / or 36 can be excluded (ie, not provided). Thus, in the example, the UBAR 2 can include the resonator body 4 without the connection structures 34 and 36. In another example, the UBAR 2 may include a resonator body 4 and a single connection structure 34 or 36. For illustration purposes only, in one preferred and non-limiting embodiment or example, a UBAR 2 comprising a resonator body 4 and connection structures 34 and 36 will be described.

Each connection structure 34 and 36 can have any suitable and / or desired shape and can be formed in any suitable and / or desired manner, with the top conductive layer 6 and any optional bottom conductive. The layer 10 can be made of any suitable and / or desired material that can facilitate the provision of separate electrical signals to it. In the example, the top conductive layer 6 is in the form of a comb tooth electrode 27 having only one rear surface 30 or 32, and the optional bottom conductive layer 10 is in the form of a comb tooth electrode 27 having only one rear surface 30 or 32. Alternatively, in the form of a sheet electrode 33, via a single connecting structure 34 or 36, which can be configured to provide separate electrical signals to the top conductive layer 6 and optionally the bottom conductive layer 10. An electrical signal can be provided to each of the top conductive layer 6 and the optional bottom conductive layer 10.

In another example, if at least one of the top conductive layer 6 or the optional bottom conductive layer 10 has the form of an alternating mating electrode 18 or comb tooth electrode 27 having two rear surfaces 30 and 32, one or more. Separate connection structures 34 and 36 may be provided to separately provide the plurality of electrical signals to the rear surfaces 24 and 26 of the alternating mating electrodes 18 and / or to the rear surfaces 30 and 32 of the comb tooth electrodes 27. The shapes of the top conductive layer 6 and the optional bottom conductive layer 10, and the methods provided to the top conductive layer 6 and the optional bottom conductive layer 10 when the electrical signal is provided, are not construed in a limited sense. And.

In one preferred and non-limiting embodiment or example, although not desired to be constrained by any particular description, example, or theory, it can be used in the example of UBAR2 shown in FIGS. 1-3. Examples of the first and second connection structures 34 and 36 will be described below.

In one preferred and non-limiting embodiment or example, for illustration purposes only, the connecting structures 34 and 36 form the various layers and the various layers forming the examples of the various resonator bodies 4 shown in FIGS. 1-3. / Or described as having an extension of the substrate. However, this allows the connection structures 34 and 36 to provide one or more separate electrical signals to the top conductive layer 6 and the optional bottom conductive layer 10 if provided. It is assumed that it may have the appropriate and / or desired shape and / or structure of, and shall not be construed in a limited sense.

5A-5B, which in one preferred and non-limiting embodiment or example can represent a diagram along lines AA and BB in any one or all of FIGS. 1-3. With reference, FIG. 5A shows the top conductive layer 6 in the form of a comb tooth electrode 27, including a rear surface 30 and an optional rear surface 32 on the top surface of the piezoelectric layer 8. In the example, the top conductive layer 6 can be in the form of alternating fitting electrodes 18 as an alternative. In one preferred and non-limiting embodiment or example, FIG. 5B shows an optional bottom conductive layer 10 in the form of a sheet electrode 33 underneath the piezoelectric layer 8 (shown by virtual lines in FIG. 5B). In the example, the optional bottom conductive layer 10 can be in the form of alternating fitting electrodes 18 or comb tooth electrodes 27 as an alternative. For the following examples only, the top conductive layer 6 and the optional bottom conductive layer 10 are in the form of a comb tooth electrode 18 including a rear surface 30 and an optional rear surface 32, and in the form of a sheet electrode 33, respectively. Explain as a thing. However, this shall not be construed in a limited sense.

In one preferred and non-limiting embodiment or example, the connecting structures 34 and 36 are bottom metal layers 40 and 44 in contact with a sheet electrode 33 forming an optional bottom conductive layer 10 of the resonator body 4 ( FIG. 5B) can be included. Each bottom layer 40 and 44 can be in the form of a thin plate covered by the piezoelectric layer 8. In the example, each bottom layer 40 and 44 can be an extension of the thin plate electrode 33 and can be formed at the same time as the thin plate electrode 33. In another example, the bottom layers 40 and 44 can be formed separately from the sheet electrode 33 and can be made of the same or different material as the sheet electrode 33. In the example, the connection structures 34 and 36 are in contact with the rear surface 30 and the rear surface 32 of the comb tooth electrode 27 forming the upper surface conductive layer 6 of the resonator body 4 and on the upper surface of the piezoelectric layer 8, respectively. Metal layers 42 and 46 can also be included.

In an example, the bottom metal layers 40 and 44 are first and second connecting structures via a conductive via 50 formed in a piezoelectric layer 8 extending between the contact pad 48 and the bottom metal layers 40 and 44. It can be connected to the contact pad 48 on the top surfaces of 34 and 36. In an example, each top metal layer 42 and 46 can have the shape of a sheet of steel spaced from the corresponding contact pad 48 by a certain gap (unnumbered). Each top metal layer 42 and 46 may also include a contact pad 58. Each contact pad 48 is a suitable signal source (not shown) that can be used to electrically drive / urge any optional bottom conductive layer 10 in any suitable and / or desired manner, as required. Can be connected to. Similarly, each contact pad 58 becomes a suitable signal source (not shown) that can be used to drive / urge the top conductive layer 6 in any suitable and / or desired manner, as needed. You can connect.

As shown in FIGS. 5A-5B with reference numbers 18 and 27, the top conductive layer 6 can be in the form of alternating mating electrodes 18 as an alternative, and the optional bottom conductive layer 10 is an alternative comb. It can be in the form of a tooth electrode 27 or an alternating fitting electrode 18.

One preferred and non-limiting embodiment or with reference to FIGS. 6A-6B, which can represent a diagram along lines AA and BB in any one or all of FIGS. 1-3. In the example, the example shown in FIGS. 6A to 6B is the same as the example shown in FIGS. 5A to 5B, excluding at least the following. The bottom metal layers 40 and 44 are in the form of a pair of spaced conductors 52 connected to an optional bottom conductive layer 10 in the form of a sheet electrode 33 by side conductors 54 and tether conductors 56, respectively (FIGS. 5A-5A). (For the conductive thin plate shown in 5B). The top metal layers 42 and 46 can be in the form of conductors 60, respectively. Each conductor 60 can be connected to the rear surface 30 or the rear surface 32 of the comb tooth electrode 27 forming the upper surface conductive layer 6 by the tether conductor 62. The tether conductor 62 can be aligned perpendicular to the tether conductor 56 and spaced from it by the piezoelectric layer 8. In the example, as shown in FIGS. 6A-6B, the width of the tether conductor 62 can be less than the width of the conductor 60, and the width of the tether conductor 56 can be approximately the same as the width of the tether conductor 62. ..

One preferred and non-limiting embodiment or with reference to FIGS. 7A-7B, which can represent a diagram along lines AA and BB in any one or all of FIGS. 1-3. In the example, the example shown in FIGS. 7A to 7B is the same as the example shown in FIGS. 6A to 6B except that at least the following is excluded. A part or all of the material of the tether conductor 62 and the connection structures 34 and 36 on both sides of the tether conductor 56 when provided in the connection structure can be removed, whereby the connection structure can be removed. Slots are formed between the rest of the body and the resonator body 4 that can extend some or all of the distance from the top to bottom of the UBAR 2 on either side of the tether conductor. The removal of part or all of the material of each of the connecting structures 34 and 36 on both sides of the tethered conductor of the connecting structure is, in the example, perpendicular to the tethered conductor 62, the tethered conductor 56 if provided, and the tethered conductor 62. A tether structure 76 can be defined that can include a portion of the piezoelectric layer 8 aligned with.

With reference to FIG. 7C and subsequently with reference to FIGS. 7A-7B, in one preferred and non-limiting embodiment or example, the tethered conductor 62 of the connecting structure and the tethered conductor 56, if provided. Removal of some or all of the material forming each of the connecting structures 34 and 36 on both sides can be used for any example of UBAR2 shown in FIGS. 1-3. For example, FIG. 7C shows the tether conductor 62 of each of the above connection structures, and the first and second connection structures 34 and the second connection structures 34 on both sides of the tether conductor 56 when provided, as shown in FIGS. 7A to 7B. A side view of the example of UBAR2 shown in FIG. 1 with 36 materials removed is shown. As can be understood from FIGS. 7A to 7C, the removed materials on both sides of the tether conductor 62 and the tether conductor 56 when provided in each connection structure are the upper surface conductive layer 6 and the piezoelectric layer. 8 and a part of the element layer 12 when the bottom conductive layer 10 of arbitrary selection is provided can be included, and as a result, in the drawings shown in FIGS. 7A to 7B, the tether conductor 62 of the connection structure and the tether conductor 62 If the tether conductor 56 is provided, no material is visible in the slots formed by the removal of these materials in each of the connecting structures 34 and 36 on either side of the tether conductor 56. In the examples shown in FIGS. 7A to 7C, each tether structure 76 has a tether conductor 62 from the top surface to the bottom surface, a part of the piezoelectric layer 8 aligned perpendicular to the tether conductor 62, and an optional tether conductor 56 (bottom surface). (When the conductive layer 10 is present) and a portion of the element layer 12 positioned perpendicular to the tether conductor 62 can be included.

In another example, a substrate 16 (FIG. 2) whose UBAR2 is shown in a virtual line in FIG. 7C and optionally one or more additional element layers 12-1 and / or substrate 16-1 (FIG. 3). When the tether conductor 62 of each connection structure 34 and 36 and the tether conductor 56 are provided, the substrate 16 and each additional element layer 12-1 and / or the substrate 16-1 are provided. When provided, the materials forming them can also be removed, and as a result, in the drawings shown in FIGS. 7A to 7B, the tether conductor 62 of the connection structure and the tether conductor 56 on both sides of the tether conductor 56 are provided. No material should be visible in the slots formed by the removal of these materials in each of the connecting structures 34 and 36.

In the example, when the figures shown in FIGS. 7A to 7B are examples of UBAR2 shown in FIG. 2, each tether structure 76 has a tether conductor 62 and a piezoelectric layer vertically aligned with the tether conductor 62 from the top surface to the bottom surface. Vertical to a part of 8 and an optional tether conductor 56 (when an optional bottom conductive layer 10 is present), a part of the element layer 12 positioned perpendicular to the tether conductor 62, and a part of the element layer 12. Can include a portion of the substrate 16 aligned with. In another example, when the figures shown in FIGS. 7A-7B are examples of UBAR2 shown in FIG. 3, each tether structure 76 is aligned perpendicular to the tether conductor 62 and the tether conductor 62 from top to bottom. A part of the piezoelectric layer 8, an optional tether conductor 56 (when an optional bottom conductive layer 10 is present), a part of the element layers 12 and 12-1 aligned perpendicular to the tether conductor 62, and a tether. It can include a portion of the substrate 16 and 16-1 aligned perpendicular to the conductor 62.

One preferred and non-limiting embodiment or with reference to FIGS. 8A-8B, which can represent a diagram along lines AA and BB in any one or all of FIGS. 1-3. In the example, the example shown in FIGS. 8A to 8B is the same as the example shown in FIGS. 7A to 7B except that at least the following is excluded. That is, the material forming all or part of at least one element layer 12 or 12-1 of each of the connection structures 34 and 36 is the tether conductor 62 of the connection structure and the tether conductor 56 when the tether conductor 56 is provided. The material of the at least one element layer 12 or 12-1 is held on both sides of the tether conductor 62 of the connection structure and, if provided with the tether conductor 56, in the slots on both sides of the tether conductor 62. appear. In the example, when the figures shown in FIGS. 8A to 8C are examples of UBAR2 shown in FIG. 1, each tether structure 76 has a tether conductor 62 and a piezoelectric layer vertically aligned with the tether conductor 62 from the top surface to the bottom surface. A part of 8 and an optional tether conductor 56 (when an optional bottom conductive layer 10 is present) can be included. In this example, the element layer 12 should be retained and visible in the slots shown in FIGS. 8A-8B.

In another example, where the figures shown in FIGS. 8A-8B are examples of UBAR2 shown in FIG. 2, each tether structure 76 is aligned perpendicular to the tether conductor 62 and the tether conductor 62 from top to bottom. It can include a portion of the piezoelectric layer 8, an optional tether conductor 56 (when the optional bottom conductive layer 10 is present), and a portion of the element layer 12 positioned perpendicular to the tether conductor 62. In this example, the element layer 12 should be retained and visible in the slots shown in FIGS. 8A-8B, while the substrate 16 below the element layer 12 (shown by virtual lines in FIG. 8C) is also retained. , Should not be visible in the slots shown in FIGS. 8A-8B.

In another example, when the figures shown in FIGS. 8A-8B are examples of UBAR2 shown in FIG. 3, each tether structure 76 is aligned perpendicular to the tether conductor 62 and the tether conductor 62 from top to bottom. It can include a portion of the piezoelectric layer 8, an optional tether conductor 56 (when the optional bottom conductive layer 10 is present), and a portion of the element layer 12 positioned perpendicular to the tether conductor 62. In the example, when the element layer 12 is retained and visible in the slots shown in FIGS. 8A-8B, the substrate 16 under the element layer 12 is also retained but visible in the slots shown in FIGS. 8A-8B. Each tether structure 76 should also include a portion of the element layer 12-1 and a portion of the substrate 16-1 aligned perpendicular to the tether conductor 62. In another example, if element layer 12-1 is retained and visible in the slots shown in FIGS. 8A-8B, substrates 16 and 16-1 and element layer 12 are also retained, but in FIGS. 8A-8B. It should not be visible in the indicated slot.

In another example shown in FIG. 8D, in the example of UBAR2 shown in FIG. 1 or 2, each tether structure 76 has a tether conductor 62 and a piezoelectric layer 8 vertically aligned with the tether conductor 62 from the top surface to the bottom surface. A part, an optional tether conductor 56 (when an optional bottom conductive layer 10 is present), and both sides of the tether conductor 62 and the tether conductor 56 of each of the connecting structures 34 and 36, if provided. It can include a portion of the body of the element layer 12 aligned perpendicular to the tether conductor 62 exposed by partial removal of the element layer 12. If the example shown in FIG. 8D is UBAR2 shown in FIG. 2, the substrate 16 (shown by a virtual line in FIG. 8D) should be held under the element layer 12 and not visible in the views shown in FIGS. 8A-8B. is there.

In another example, in the example of UBAR2 shown in FIG. 3, each tether structure 76 is optionally selected from top to bottom with a tether conductor 62 and a portion of the piezoelectric layer 8 positioned perpendicular to the tether conductor 62. The element layers 12 or 12 on both sides of the tether conductor 56 (when an optional bottom conductive layer 10 is present), the tether conductor 62 of each of the connecting structures 34 and 36, and the tether conductor 56 when provided. Includes element layer 12 or part of the body of element layer 12-1 aligned perpendicular to the tether conductor 62 exposed by partial removal of -1 (similar to partial removal of element layer 12 shown in FIG. 8D). be able to. In the example, a part of the main body of the element layer 12 of UBAR2 shown in FIG. 3 is removed (similar to the partial removal of the element layer 12 shown in FIG. 8D), and as a result, the element layer 12 of UBAR2 shown in FIG. 3 is formed. A portion of the interior of the material may be visible in the slots shown in FIGS. 8A-8B, and each tether structure 76 may also include a portion of the device layer 12-1 and substrate 16-1 aligned perpendicular to the tether conductor 62. it can. In this example, the substrate 16 is retained, i.e., the substrate 16 has no portion to be removed and should not be visible in the figures shown in FIGS. 8A-8B.

In another example, a portion of the body of the element layer 12-1 of UBAR2 shown in FIG. 3 is removed (similar to the partial removal of the element layer 12 shown in FIG. 8D), resulting in the formation of the element layer 12-1. A portion of the interior of the material is visible in the slots shown in FIGS. 8A-8B, and each tether structure 76 may also include a portion of the body of the device layer 12-1 aligned perpendicular to the tether conductor 62. In this example, the substrates 16 and 16-1 and the element layer 12 are retained, that is, the substrates 16 and 16-1 and the element layer 12 have no portions to be removed and are not visible in the figures shown in FIGS. 8A-8B. Should be.

With reference to FIGS. 9A-9B, which can represent a diagram along lines AA and BB in any one or all of FIGS. 1-3, in UBAR2 shown in FIG. 2, one preferred and In a non-limiting embodiment or example, the examples shown in FIGS. 9A-9B are similar to the examples shown in FIGS. 8A-8B, with at least the following exceptions: Each tether structure 76 can include a portion of the material forming the element layer 12, so that in the figure shown in FIGS. 9A-9C, a portion of the substrate 16 is a tether conductor of the connection structures 34 and 36. If the tether conductor 56 is provided with the 62, it can be seen in the slots formed on both sides of the tether conductor 56. In this example, the substrate 16 is held and each tether structure 76 has a tether conductor 62, a portion of the piezoelectric layer 8 positioned perpendicular to the tether conductor 62, and an optional tether conductor 56 (from top to bottom. (When an optional bottom conductive layer 10 is present) and a portion of the element layer 12 positioned perpendicular to the tether conductor 62 can be included.

Continuing with reference to FIGS. 9A-9B, in UBAR2 shown in FIG. 3, in one preferred and non-limiting embodiment or example, where the element layer 12 and the substrates 16 and 16-1 are retained, FIGS. 9A-9B In the figure shown in the above, the substrate 16-1 can be seen in the slots formed on both sides of the tether conductor 62 and the tether conductor 56 of each of the connection structures 34 and 36 when the tether conductor 56 is provided. In this example, each tether structure 76 has a tether conductor 62, a part of a piezoelectric layer 8 vertically aligned with the tether conductor 62, and an optional tether conductor 56 (an optional bottom conductive layer) from the top surface to the bottom surface. (When 10 is present) and a portion of the element layer 12-1 aligned perpendicular to the tether conductor 62.

In another example, in UBAR2 shown in FIG. 3, the substrate 16 is held, and as a result, in the figures shown in FIGS. 9A-9B, the substrate 16 is the tether conductor 62 and the tether conductor of the connecting structures 34 and 36, respectively. If 56 is provided and can be seen in the slots formed on both sides of the 56, each tether structure 76 is a portion of the tether conductor 62 and the piezoelectric layer 8 vertically aligned with the tether conductor 62 from top to bottom. And the optional tether conductor 56 (when the optional bottom conductive layer 10 is present), a part of the element layer 12-1 aligned perpendicular to the tether conductor 62, and the alignment perpendicular to the tether conductor 62. A portion of the substrate 16-1 that has been formed and a portion of the element layer 12 that is aligned perpendicular to the tether conductor 62 can be included.

In another example shown in FIG. 9D, in the example of UBAR2 shown in FIG. 2, at the interface between the substrate 16 and the element layer 12, a part of the material forming the main body of the substrate 16 is divided into the resonator main body 4 and the connection structure 34. Can be removed laterally under and 36, resulting in exposed bottom portions 64 and 70 of the connection structures 34 and 36 and bottom portions 66 and 68 of the resonator body 4, as shown in FIG. 9D. Is exposed, and the surfaces 72 and 74 of the main body of the substrate 16 are exposed. In this example, the removed portion of the material forming the body of the substrate 16 can extend in the plane of FIG. 9D to a portion of the material of the substrate 16 aligned perpendicular to each tether structure 76. In this example, each tether structure 76 has a tether conductor 62, a part of a piezoelectric layer 8 vertically aligned with the tether conductor 62, and an optional tether conductor 56 (an optional bottom conductive layer) from the top surface to the bottom surface. (When 10 is present), a part of the element layer 12 positioned perpendicular to the tether conductor 62, and a part of the substrate 16 positioned perpendicular to the tether conductor 62 close to the part of the element layer 12. Can include. In this example, the surfaces 72 and 74 may be visible in the slots shown in FIGS. 9A-9B.

In another alternative, in the UBAR2 example shown in FIG. 3, a portion of the material forming the substrate 16-1 or 16 is connected to the resonator body 4 as well as the removal of the material forming the substrate 16 in FIG. 9D. It can be removed laterally under the structures 34 and 36, so that the surface of the material forming the substrate 16-1 or 16 (such as surfaces 72 and 74) is exposed and the slots shown in FIGS. 9A-9B. Can be seen inside.

In an example, the surfaces of the material forming the substrate 16-1 of the UBAR2 example of FIG. 3 (such as surfaces 72 and 74) may be exposed and visible in the slots shown in FIGS. 9A-9B, with each tether structure 76 being tethered. Includes a portion of the element layer 12-1 aligned perpendicular to the conductor 62 and a portion of the material forming the substrate 16-1 positioned perpendicular to the tether conductor 62 in close proximity to the element layer 12-1. You can also do it. In this example, only a part of the main body of the substrate 16-1 is removed to form each slot and the element layer 12 and the substrate 16 are held, that is, the element layer 12 and the substrate 16 have no portion to be removed. , Not visible in the figures shown in FIGS. 9A-9B.

In another example, the surfaces of the material forming the substrate 16 of the UBAR2 example of FIG. 3 (such as surfaces 72 and 74) may be exposed and visible in the slots shown in FIGS. 9A-9B, with each tether structure 76 being a tether. A part of the element layer 12-1 vertically aligned with the conductor 62, a part of the substrate 16-1 vertically aligned with the tether conductor 62, and a part of the element layer 12 vertically aligned with the tether conductor 62. It may also include a portion and a portion of the material that forms the substrate 16 that is positioned perpendicular to the tether conductor 62 in close proximity to the element layer 12. In this example, only a portion of the body of the substrate 16 is removed to form each slot.

In one preferred and non-limiting embodiment or example, where the bottom conductive layer 10 is absent, in any of the examples discussed above, the bottom metal layers 40 and 44 of the connecting structures 34 and 36 are It does not have to exist.

In one preferred and non-limiting embodiment or example, each tether structure 76 described above comprises at least a tether conductor 62 and an optional tether conductor 56 (when an optional bottom conductive layer 10 is present). , Only a portion of the piezoelectric layer 8 aligned perpendicular to the tether conductor 62 can be included. In another preferred and non-limiting embodiment or example, each tether structure 76 is positioned perpendicular to the tether conductor 62, element layer 12, substrate 16, element layer 16-1 and / or substrate 16-. It may also include only one or more parts of one. However, this shall not be construed in a limited sense.

In one preferred and non-limiting embodiment or example, in each example of the resonator body 4 shown in FIGS. 1 to 3, at least the top conductive layer 6 and the optional bottom conductive layer 10 are provided, and the top surface. The widths of the part of the piezoelectric layer 8 under the conductive layer 6 can all be the same. Alternatively, or as an alternative, in the example, the width and / or dimensions of the element layer 12, the substrate 16, and the element layers 12-1 and / or the substrate 16-1 are all the top conductive layers. 6 and the case where the bottom conductive layer 10 of arbitrary selection is provided, the width and / or the dimension of the piezoelectric layer 8 can be the same.

In one preferred and non-limiting embodiment or example, any one or more of the surfaces of the example of any resonator body 4 shown in FIGS. 1-3, and / or any one or more. When the connection structures 34 and / or 36 are provided, one or all of their surfaces are etched when deemed appropriate and / or desirable, and examples of any UBAR2 shown in FIGS. 1-3. Quality factor and / or insertion loss can be optimized. For example, the top and bottom surfaces of the example of any resonator body 4 shown in FIGS. 1 to 3 can be etched. Alternatively, or as an alternative, one or more sides of any of the resonator body 4 examples shown in FIGS. 1-3 can be etched so that each of the sides is vertically flat. Can be done.

In one preferred and non-limiting embodiment or example, if the top conductive layer 6 or optionally the bottom conductive layer 10 is provided, the bottom conductive layer 10 or both are in the form of alternating mating electrodes 18. One rear surface 22 or 26 of the alternating mating electrode 18 can be connected to a suitable signal source and driven by a suitable signal source, while the other rear surface 22 or 26 is connected to the signal source. Can not be. In another preferred and non-limiting embodiment or example, if the top conductive layer 6 or optionally bottom conductive layer 10 is provided, the bottom conductive layer 10 or both are in the form of alternating mating electrodes 18. The rear surface 22 of the alternating mating electrode 18 is connected to one signal source and can be driven by one signal source, and the rear surface 26 of the alternating mating electrode 18 is connected to a second signal source. It can be driven by a second signal source. In an example, the second source can be the same as or different from the first source.

In one preferred and non-limiting embodiment or example, each embodiment of the device layer 12 (or 12-1) can have an acoustic impedance of 60 × 10 ⁶ Pa · s / m ³ or greater. In another example, each specific example of the element layer 12 (or 12-1) can have an acoustic impedance of 90 × 10 ⁶ Pa · s / m ³ or more. In another example, each specific example of the element layer 12 (or 12-1) can have an acoustic impedance of 500 × 10 ⁶ Pa · s / m ³ or more. In one preferred and non-limiting embodiment or example, each substrate layer 16 can have an acoustic impedance of 100 × 10 ⁶ Pa · s / m ³ or less. In another example, each substrate layer 16 can have an acoustic impedance of 60 × 10 ⁶ Pa · s / m ³ or less.

In one preferred and non-limiting embodiment or example, the reflectance (R) of the acoustic wave at the interface between the element layer 12 and the piezoelectric layer 8 or the optional bottom conductive layer 10 is 50%. Can be super. In another example, when the element layer 12 and the piezoelectric layer 8 or the bottom conductive layer 10 of the option are provided, the reflectance (R) of the acoustic wave at the interface between them can be more than 70%. In another example, when the element layer 12 and the piezoelectric layer 8 or the bottom conductive layer 10 of the option are provided, the reflectance (R) of the acoustic wave at the interface between them can be more than 90%.

In one preferred and non-limiting embodiment or example, the reflectance (R) of the acoustic wave at the interface between the device layer 12 or 12-1 and the piezoelectric layer 8 or the optional bottom conductive layer 10 provided. Can be over 70%. In an example, at the interface 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 element layer 12 Alternatively, the reflectance R at the interface between 12-1 and the substrate 16 or 16-1 can be obtained by the following formula.

R = | (Zb-Za) / (Za + Zb) |

Here, Za = the acoustic impedance of the bottom conductive layer 10 when an optional bottom conductive layer 10 located on the piezoelectric layer 8, for example, or the second layer is provided.

Zb = acoustic impedance of the second layer, for example, the element layer 12.

Other examples of the first and second layers can include specific examples of the element layer 12 or 12-1 on the substrate 16 or 16-1.

In one preferred and non-limiting embodiment or example, the total reflectance (R) of the example of any resonator body 4 shown in FIGS. 1-3 can be> 90%.

In one preferred and non-limiting embodiment or example, the device layer 12 can be a layer of diamond or SiC formed in a manner well known in the art. In the example, the substrate 16 can be formed from silicon.

In one preferred and non-limiting embodiment or example, the element layer 12 formed of diamond is a chemical vapor deposition (CVD) of diamond on a substrate 16 or 16-1 or a sacrificial substrate (not shown). Can be grown by. In one preferred and non-limiting embodiment or example, the optional bottom conductive layer 10, piezoelectric layer 8, and top conductive layer 6 utilize conventional semiconductor processing techniques not further described herein. , Can be deposited on the element layer 12 and patterned as needed (eg, comb tooth electrode 27 or alternating mating electrode 18).

As used herein, each temperature compensating layer 90, 92, and 94 may contain at least one of silicon and oxygen. For example, each temperature compensating layer can contain silicon dioxide, or elemental silicon, and / or elemental oxygen.

In one preferred and non-limiting embodiment or example, each UBAR2 shown in FIGS. 1-3 can have a no-load quality factor of 100 or greater. In another example, each UBAR2 shown in FIGS. 1-3 can have a no-load quality factor of 50 or greater. When the piezoelectric layer 8, each element layer 12, and each substrate 16 of the example of each resonator body 4 shown in FIGS. 1 to 3 are provided in one preferable and non-limiting embodiment or example, the thickness of each substrate 16 The performance of the resonator body 4 can be optimized by selecting it in any suitable and / or desired manner. Similarly, in the examples, the dimensions of each resonator body 4 example shown in FIGS. 1-3 can be selected indefinitely for target performance such as insertion loss, power processing capacity, and heat dissipation. In one preferred and non-limiting embodiment or example, when diamond is used as the material for the device layer 12, the surface of the diamond layer at the interface with the bottom layer 12 is optically finished and / or physically. Can be made dense. In the example, the diamond material forming the element layer 12 can be undoped or doped, eg, P-type or N-type. The diamond material can be polycrystalline, nanocrystal, or ultra-nanocrystal. In an example, when silicon is used as the material for each of the specific examples of substrate 16, the silicon is undoped or doped, eg, P-type or N-type, and is single crystal or polycrystalline. There can be. The diamond material forming the element layer can have a Raman half width of 20 cm- ¹ or less.

In one preferred and non-limiting embodiment or example, the piezoelectric layer 8 is 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. It can be formed in the doped form of tantalite, GaN, AlGaN, lead zirconate titanate (PZT), polymers or any of the above materials.

In one preferred and non-limiting embodiment or example, the device layer 12 can be formed of any suitable and / or desired high acoustic impedance material. In the example, a material having an acoustic impedance between 10 ⁶ Pa · s / m ³ and 630 × 10 ⁶ Pa · s / m ³ or higher can be regarded as a high acoustic impedance material. For example, some non-limiting examples of typical high acoustic impedance materials that can be used to form any of the elemental layers 12 described herein include diamonds (approximately 630 × 10 ⁶ Pa · s). / M ³ ); W (about 99.7 × 10 ⁶ Pa · s / m ³ ); SiC; Condensed phase material such as metal, eg, Al, Pt, Pd, Mo, Cr, Ir, Ti, Ta; Period Group 3A or 4A elements in the table; transition elements of groups 1B, 2B, 3B, 4B, 5B, 6B, 7B, or 8B in the periodic table; ceramics; glass, and polymers may be included. This list of unrestricted examples of high acoustic impedance materials shall not be construed in a limited sense.

In one preferred and non-limiting embodiment or example, the substrate 16 can be formed of any suitable and / or desired low acoustic impedance material. In the example, a material having an acoustic impedance between 10 ⁶ Pa · s / m ³ and 30 × 10 ⁶ Pa · s / m ³ can be considered as a low acoustic impedance material. For example, for some non-limiting examples of typical low acoustic impedance material that can be used to form any of the substrate 16 as described herein are ceramic; from 10 6 ^Pa · s / m ³ Glasses, crystals, minerals, and metals with acoustic impedance between 30 × 10 ⁶ Pa · s / m ³ ; ivory (1.4 × 10 ⁶ Pa · s / m ³ ); alumina / sapphire (25.5 × Of 10 ⁶ Pa · s / m ³ ); alkali metal K (1.4 × 10 ⁶ Pa · s / m ³ ); SiO ₂ , and silicon (19.7 × 10 ⁶ Pa · s / m ³ ). At least one may be included. This list of unrestricted examples of low acoustic impedance materials shall not be construed in a limited sense.

In one preferred and non-limiting embodiment or example, the choice of material forming the example of each resonator body 4 allows one or more materials to be typically considered high acoustic impedance material to be the resonator. It can function as a low acoustic impedance material of the main body 4. For example, when diamond or SiC is used as the material for the element layer 12, W can be used as the material for the substrate 16. Therefore, which material can be used as the high acoustic impedance material and which material is the low acoustic impedance material by achieving the desired reflectance R (discussed above) at the interface between the two layers of the resonator body 4 or the substrate. Can be used as.

In one preferred and non-limiting embodiment or example, the bulk acoustic resonator according to the principles of the present invention may include a resonator body 4. The resonator main body 4 can include a piezoelectric layer 8, an element layer 12, and an upper surface conductive layer 6 on the piezoelectric layer 8 on the opposite side of the element layer 12. Virtually all of the surface of the element layer 12 on the opposite side of the piezoelectric layer is for mounting the resonator body 4 on a carrier 14 separated from the resonator body 4. In the example, it is desirable, but not absolutely essential, that all of the surface of the element layer opposite the piezoelectric layer could be for mounting the entire resonator body on the carrier. In an example, it is desirable, but not absolutely necessary, for the bulk acoustic resonator to include a connecting structure 34 or 36 to conduct the signal to the top conductive layer. In the example, the device layer can include diamond or SiC. In the example, the top conductive layer 6 can include a plurality of spaced conductive wires or fingers. In the example, the resonator main body 4 may further include an optional bottom conductive layer 10 between the piezoelectric layer 8 and the element layer 12.

In one preferred and non-limiting embodiment or example, the resonator body 4 may further include a substrate 16 attached to an element layer 12 opposite the piezoelectric layer 8. In the example, the entire surface of the element layer 12 can be mounted on the substrate 16. In the example, the surface of the substrate 16 facing the carrier 14 can be there for mounting the entire surface directly on the carrier 14.

In one preferred and non-limiting embodiment or example, the entire surface of the device layer 12 facing the carrier 14 can be mounted directly on the substrate 16. In the example, the surface of the element layer 12 facing the carrier 14 is for mounting the entire surface directly on the carrier 14.

In one preferred and non-limiting embodiment or example, the resonator body 4 has a second element layer 12-1 between the substrate 16 and the piezoelectric layer 8 or between the substrate 16 and the piezoelectric layer 8. Can further include a second substrate 16-1 or both.

In one preferred and non-limiting embodiment or example, as used herein, "mounting inity" refers to one layer or substrate directly or indirectly to another layer or substrate. Can be meant to be implemented in. In an example, as used herein, "mounting inity" is also, or as an alternative, intentionally between one layer or substrate and another layer or substrate. It can mean that there are no introduced spaces or gaps. In another example, herein, "mounting institutionity" is also, or as an alternative, natural between one layer or substrate and another layer or substrate. Can include naturally occurring spaces that can be formed (but unintentionally).

Having described some non-limiting embodiments or examples of UBAR in this way, the first to sixth examples of UBAR will be described next.

First example of UBAR: device layer effective mode 3 and / or mode 4 resonance with the presence of a temperature compensation layer

Returning to FIG. 1, in some non-limiting embodiments or examples, the first example of UBAR2 (shown in FIG. 1) is a spaced conductive wire or wire from its top surface to the carrier 14. It includes a finger 20 or 28 (shown in FIGS. 4A-4B), a piezoelectric layer 8 formed of LiNbO ₃ , a temperature compensation layer 92 formed of SiO ₂ , and an element layer 12 formed of diamond or SiC. The upper surface conductive layer 6 can be included. In the example, the finger pitch 38 (shown in FIGS. 4A-4B) is 0.6 μm, and the piezoelectric layer 8 has a thickness of 0.6 μm.

Throughout the disclosure, the value of the variable "λ" can be based on one or more dimensions of the pattern or feature defined by the top conductive layer 6 or based on the thickness of the piezoelectric layer 8. In some non-limiting embodiments or examples, the value of λ may be equal to twice the finger pitch 38, or twice the thickness of the piezoelectric layer 8 (1.2 μm in this example). May be equal to. However, the value of λ is for any other suitable and / or desired size and / or one or more layers of one or more other patterns or features of each UBAR example described herein. This shall not be construed in a limited sense as it may be based on thickness. In this example, the cut angle of the piezoelectric layer 8 was 0 ° (or 180 °), sometimes referred to as Y-cut or YX-cut. In some non-limiting embodiments or examples, the use of a cut angle of the piezoelectric layer 8 of 0 ° (or 180 °) ± 20 ° is envisioned. In the present specification, unless otherwise specified, the cut angle of the piezoelectric layer 8 is based on the cut angle rotated about the X axis.

In some non-limiting embodiments or examples, in order to model the first example of UBAR2, the frequency response (frequency vs. amplitude) is determined by the thickness of the temperature compensating layer 92 formed of SiO _2. For the or several different exemplary values, the frequency sweep of the exemplary electrical stimuli added to this first example of UBAR2 (eg, from 1 GHz to 6.2 GHz) was determined. In the modeling example, the thickness of the temperature compensating layer 92 formed of SiO ₂ is varied between (9/16) λ and (1/64) λ, and the first UBAR2 for each value of thickness. The frequency of the exemplary electrical stimulation added to the example was varied from at least 1 GHz to 6.2 GHz. In an example, a first plot, graph, or relationship of frequency vs. amplitude, eg, for a frequency sweep of at least between 1 GHz and 6.2 GHz with respect to the thickness of the temperature compensation layer 92 of (9/16) λ. I asked. In the example, another plot, graph, or relationship of frequency vs. amplitude was determined, for example, for frequency sweeping between 1 GHz and 6.2 GHz with respect to the thickness of the temperature compensating layer 92 of (3/64) λ. .. Additional plots, graphs, or relationships of frequency vs. amplitude were determined for frequency sweeps of other thicknesses of the temperature compensation layer 92.

At least a mode 4 resonant frequency 88 (FIGS. 10 and 11) was observed for each plot, graph, or relationship of frequency vs. amplitude. However, in the first example of this UBAR, surprisingly, the mode 4 resonance frequency 88 is observed at about 5.2 GHz with respect to the mode 4 resonance frequency 88 of 3.05 GHz shown in FIG. 10 (FIG. 11). , Mode 3 resonant frequency 86 (FIG. 11) was observed at about 3.13 GHz.

In FIG. 11, mode 1 and mode 2 resonant frequencies 82 and 84 (eg, shown in FIG. 10) are omitted to the left of mode 3 resonant frequency 86 for brevity. However, for frequency sweeps between at least 1 GHz and 6.2 GHz, Mode 1 and Mode 2 resonant frequencies 82 and 84 (eg, shown in FIG. 10) are present in addition to Mode 3 and Mode 4 resonant frequencies 86 and 88. Please understand that it is okay.

In some non-limiting embodiments or examples, for example, as shown in FIG. 11, each plot, graph, or relationship of frequency vs. amplitude is a positive peak value of f _s1 and f at mode 3 resonant frequency 86. _It includes a negative peak value of _p1 and includes a positive peak value of f _s2 and a negative peak value of f _{p2 at} the mode 4 resonance frequency 88.

For illustration purposes only, here the "resonant frequency" observed "with respect to" a particular frequency is between the positive peak value f _s1 and the negative peak value f _p1 at mode 3 resonant frequency 86. , And mode 4 resonance frequency 88 can be any representative frequency between the positive peak value f _s2 and the negative peak value f _p2 . Therefore, any resonant frequency described herein as "with respect" to a particular frequency shall not be construed in a limited sense.

In some non-limiting embodiments or examples, the mode 3 and mode 4 resonant frequencies 86 and 88 are mode 3 coupled to the thickness (1/16) λ of the temperature compensating layer 92 formed of SiO _2. The efficiency (M3CE) and the 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)
Here, for the exemplary values of f _p1 and f _s1 equal to 3.738 GHz and 3.13 GHz, respectively.
For exemplary values of f _p2 and f _s2 equal to M3CE = 40.093%, and 5.442 GHz and 5.172 GHz, respectively.
M4CE = 12.229%

However, the aforementioned values of M3CE in this example may be appropriate and / or desirable, with M3CE values of 8% or higher, 11% or higher, 14% or higher, 17% or higher, or 20% or higher being satisfactory. Therefore, it shall not be interpreted in a limited sense. Alternatively, or as an alternative, the aforementioned values for M4CE in this example are appropriate and / / for which values of M4CE of 3% or higher, 4% or higher, 6% or higher, 8% or higher, or 10% or higher are satisfactory. Or it may be desirable and shall not be construed in a limited sense.

In some non-limiting embodiments or examples, where specific values of M3CE, such as 8% or higher, 11% or higher, 14% or higher, 17% or higher, or 20% or higher, are desired, the piezoelectric layer. The cut angle of 8 exceeds the above cut angle of 0 ° (or 180 °) ± 20 °, for example, 0 ° (or 180 °) ± 20 ° or more, ± 30 ° or more, ± 40 ° or more, ± It can reach a cutting angle such as 50 ° or more. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M3CE. May be sufficient for

In some non-limiting embodiments or examples, when a level of M4CE, eg, 3% or more, 4% or more, 6% or more, 8% or more, or 10% or more is desired, the piezoelectric layer 8 The cut angle exceeds the cut angle of 130 ° ± 30 ° (sometimes called Y cut 130 ± 30 or YX cut 130 ± 30), for example, 130 ° ± 30 ° or more, ± 40 ° or more, ± 50. It can reach cut angles such as ° or more. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M4CE. May be sufficient for

In some non-limiting embodiments or examples, plots, graphs, or graphs of frequency vs. amplitude obtained in the manner described above for some values of the thickness of equations EQ1 and EQ2 and the temperature compensation layer 92. The thickness values of the temperature compensation layer 92 formed of SiO ₂ that optimizes the mode 3 and mode 4 resonance frequencies using the relationship are (3/64) λ and (1/32) λ, respectively. Was decided. However, these thickness values are such that the thickness of the temperature compensating layer 92 formed of SiO ₂ is any suitable and / or preferably unlimited, 1λ or less, (1/2) λ or less, (3). Since it may have a thickness of / 8) λ or less, (1/4) λ or less, or (1/8) λ or less, it shall not be interpreted in a limited sense.

Second example of UBAR: device layer effective mode 3 and / or mode 4 resonance without temperature compensating layer

In some non-limiting embodiments or examples, for comparison and / or modeling, the frequency response is described above in most respects except that the second example of UBAR2 excludes the temperature compensating layer 92. The frequency sweep (eg, from 1 GHz to 6.2 GHz) of an exemplary electrical stimulus added to the second example of UBAR2, which is similar to the first example of UBAR2 described in (1). .. Frequency vs. amplitude plots, graphs, or relationships were sought for frequency sweeps.

Using the frequency vs. amplitude plots, graphs, or relationships obtained for equations EQ1 and EQ2 and frequency sweep, the coupling efficiencies M3CE and M4CE of Mode 3 and Mode 4 resonant frequencies 86 and 88 of the second example of UBAR2 are It was determined to be the following value:
M3CE = 40.093% for the values of f _p1 and f _s1 equal to 3.738 GHz and 3.13 GHz, respectively.
And M4CE = 9.312% for values of f _p2 and f _s2 equal to 6.194 GHz and 5.96 GHz, respectively.

However, the aforementioned values of M3CE in this example may be appropriate and / or desirable, with M3CE values of 8% or higher, 11% or higher, 14% or higher, 17% or higher, or 20% or higher being satisfactory. Therefore, it shall not be interpreted in a limited sense. Alternatively, or as an alternative, the aforementioned values for M4CE in this example are appropriate and / / for which values of M4CE of 3% or higher, 4% or higher, 6% or higher, 8% or higher, or 10% or higher are satisfactory. Or it may be desirable and shall not be construed in a limited sense.

In some non-limiting embodiments or examples, where specific values of M3CE, such as 8% or higher, 11% or higher, 14% or higher, 17% or higher, or 20% or higher, are desired, the piezoelectric layer. The cut angle of 8 exceeds the above cut angle of 0 ° (or 180 °) ± 20 °, for example, 0 ° (or 180 °) ± 20 ° or more, ± 30 ° or more, ± 40 ° or more, ± It can reach a cutting angle such as 50 ° or more. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M3CE. May be sufficient for

In some non-limiting embodiments or examples, when a level of M4CE, eg, 3% or more, 4% or more, 6% or more, 8% or more, or 10% or more is desired, the piezoelectric layer 8 The cut angle exceeds the cut angle of 130 ° ± 30 ° (sometimes called Y cut 130 ± 30 or YX cut 130 ± 30), for example, 130 ° ± 30 ° or more, ± 40 ° or more, ± 50. It can reach cut angles such as ° or more. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M4CE. May be sufficient for

As can be seen from the M4CE values of UBAR2 with and without the temperature compensating layer 92 described above, the coupling efficiency may be greater for UBAR2 with the temperature compensating layer 92 of SiO ₂ , and vice versa. In addition, the coupling efficiency may be smaller in UBAR ₂ which does not have the temperature compensation layer 92 of SiO ₂ . In some non-limiting embodiments or examples, higher values of binding efficiency are generally more desirable.

Third example of UBAR: device layer effective mode 3 and / or mode 4 resonance with the presence of a temperature compensating layer and a layer of aluminum nitride

With reference to FIG. 12 and continuing with reference to FIG. 11, in some non-limiting embodiments or examples, for comparison and / or modeling, the frequency response is, with the exception of at least the following, i.e., UBAR2. A third example includes a layer of AlN96 between the element layer 12 of diamond or SiC and the temperature compensating layer 92 of SiO ₂ shown above the AlN layer 96 in FIG. 12, and the AlN layer 96 is (7/16). ) Λ, the temperature compensation layer 92 of SiO ₂ has a thickness of (11/128) λ, and the element layer 12 made of diamond or SiC has a thickness (90/16). Frequency sweep of exemplary electrical stimulation added to a third example of UBAR2 (shown in FIG. 12), which is similar to the first example of UBAR2 described above in most respects, except that it has λ. (For example, from 1 GHz to 6.2 GHz) was determined. In this example, λ is equal to 1.6 μm. Frequency vs. amplitude plots, graphs, or relationships were sought for frequency sweeps.

Using the frequency-to-amplitude plots, graphs, or relationships obtained for equations EQ1 and EQ2 and frequency sweep, the coupling efficiency M3CE for mode 3 and mode 4 resonant frequencies 86 and 88 of the third example of UBAR2 shown in FIG. And M4CE were determined to be:
M3CE = 39.351% for values of f _p1 and f _s1 equal to 3.608 GHz and 3.032 GHz, respectively.
And M4CE = 10.802% for values of f _p2 and f _s2 equal to 5.02 GHz and 4.8 GHz, respectively.

However, the aforementioned values of M3CE in this example may be appropriate and / or desirable, with M3CE values of 8% or higher, 11% or higher, 14% or higher, 17% or higher, or 20% or higher being satisfactory. Therefore, it shall not be interpreted in a limited sense. Alternatively, or as an alternative, the aforementioned values for M4CE in this example are appropriate and / / for which values of M4CE of 3% or higher, 4% or higher, 6% or higher, 8% or higher, or 10% or higher are satisfactory. Or it may be desirable and shall not be construed in a limited sense.

In some non-limiting embodiments or examples, where specific values of M3CE, such as 8% or higher, 11% or higher, 14% or higher, 17% or higher, or 20% or higher, are desired, the piezoelectric layer. The cut angle of 8 exceeds the above cut angle of 0 ° (or 180 °) ± 20 °, for example, 0 ° (or 180 °) ± 20 ° or more, ± 30 ° or more, ± 40 ° or more, ± It can reach a cutting angle such as 50 ° or more. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M3CE. May be sufficient for

In some non-limiting embodiments or examples, when a level of M4CE, eg, 3% or more, 4% or more, 6% or more, 8% or more, or 10% or more is desired, the piezoelectric layer 8 The cut angle exceeds the cut angle of 130 ° ± 30 ° (sometimes called Y cut 130 ± 30 or YX cut 130 ± 30), for example, 130 ° ± 30 ° or more, ± 40 ° or more, ± 50. It can reach cut angles such as ° or more. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M4CE. May be sufficient for

In the above examples of the first to third examples of UBAR, M3CE and M4CE were determined for the piezoelectric layer 8 formed of LiNbO ₃ crystals cut at an angle of 0 ° (or 180 °). In some non-limiting embodiments or examples, the piezoelectric layer 8 formed of LiNbO ₃ crystals cut at an angle of about 130 ° (sometimes referred to as YX cut 130 ° or Y cut 130 °) The applicant has found that the coupling efficiency M4CE at mode 4 resonance frequency 88 can be improved or optimized. In the example, the cut angle of the piezoelectric layer 8 formed of LiNbO ₃ crystals is, for example, 130 ° ± 30 ° in the range between 100 ° and 160 °, more preferably between 110 ° and 150 °, for example. It can be 130 ° ± 20 ° in the range, most preferably 130 ° ± 10 ° in the range 120 ° to 140 °. However, these ± values or ranges shall not be construed in a limited sense.

In addition, in some non-limiting embodiments or examples, it was formed of LiNbO ₃ crystals cut at an angle of about 130 ° (± 30 °, or ± 20 °, or ± 10 °) of the piezoelectric layer 8. ) And the element layer 12 (when the substrate 16 is omitted) or the substrate 16 (when the element layer 12 is omitted), or when both the element layer 12 and the substrate 16 are present, the low between both. And the applicant has found that UBAR2 formed with alternating layers of high acoustic impedance material can also improve or optimize the coupling efficiency M4CE of mode 4 resonant frequency 88. In some non-limiting embodiments or examples, UBAR2 formed with overlapping layers of low and high acoustic impedance materials is with element layer 12 made of diamond, SiC, W, Ir, or AlN. , A substrate 16 made of silicon and can be included. In some non-limiting embodiments or examples, UBAR2 formed with alternating layers of low and high acoustic impedance materials can include a substrate 16 made of silicon, but an element layer. 12 can be excluded.

Fourth Example of UBAR: Bending mode enabled by a stack that includes at least a low acoustic impedance layer and a high acoustic impedance layer and optionally has an element layer (mode 4).

With reference to FIG. 13 and continuing with reference to FIG. 11, in some non-limiting embodiments or examples, a fourth example of UBAR2 formed of alternating layers of low and high acoustic impedance materials (FIG. 13). (Shown in 13) is the element layer (optional) from the piezoelectric layer 8 (formed of LiNbO ₃ crystals cut at an angle of about 130 ° (± 30 °, or ± 20 °, or ± 10 °)). By 12 or the substrate 16, the first low acoustic impedance layer 100, the first high acoustic impedance layer 102, the second low acoustic impedance layer 104, the second high acoustic impedance layer 106, and the third A low acoustic impedance layer 108 can be included. In this example, the spaced conductive wire or finger 20 or 28 of the top electrode 6 has a finger pitch 38 (shown in FIGS. 4A-4B) of 1.2 μm, a value of λ of 2.4 μm, and a piezoelectric wire. The thickness of the layer is λ / 2, the thickness of the element layer 12 is 4λ when present, and the thickness of the substrate 16 is 20 μm. In this example, for modeling purposes, the cut angle of the piezoelectric layer 8 was varied between 100 ° and 160 °.

In some non-limiting embodiments or examples, the low acoustic impedance layers 100, 104, and 108 can be formed of silicon dioxide (SiO ₂ ), and the high acoustic impedance layers 102 and 106 are eg, for example. , Tungsten (W) and the like, the element layer 10 can be made of diamond or SiC, and the substrate 16 can be made of silicon. In the example, the element layer 12 can be optional, so that the third low acoustic impedance layer 108 can come into direct contact with the substrate 12 and the second high acoustic impedance layer 106.

In some non-limiting embodiments or examples, the frequency response (frequency vs. amplitude) is, for example, 100 ° to 160, as described above for the first example of UBAR2, to model. For each of the several different cut angles of the piezoelectric layer 8 varied between °, for each of the several different exemplary values of the thickness of the low acoustic impedance layers 100, 104, and 108. , And for some different exemplary values of the thickness of the high acoustic impedance layers 102 and 106, the illustrations added to the fourth example of some UBAR2 with and without the element layer 12. Frequency sweep of electrical stimulation (eg, from 1 GHz to 6.2 GHz) was determined. In other words, the frequency response (frequency vs. amplitude) is (1) no element layer 12 or element layer 12, (2) the cut angle of the piezoelectric layer 8 varied between 100 ° and 160 °, and (3) low acoustics. Illustrative additions to the fourth example of some UBAR2 with different combinations of thickness values of impedance layers 100, 104, and 108, and (4) thickness values of high acoustic impedance layers 102 and 106. Frequency sweep of electrical stimulation (eg, from 1 GHz to 6.2 GHz) was determined.

In some non-limiting embodiments or examples, for each cut angle of the piezoelectric layer 8, the thickness of each low acoustic impedance layer 100, 104, and 108 is set to the same (first) value. The thickness of each high acoustic impedance layer 102 and 106 is set to the same (second) value, and the frequency of the exemplary electrical stimulation added to the fourth example of UBAR2 is, for example, 1 GHz to 6.2 GHz. The frequency response of the fourth example of UBAR2 to the sweep was recorded. Then, the value of only the thickness of the low acoustic impedance layer (first value) or the value of the thickness of the high acoustic impedance layer (second value) is changed, the frequency sweep is repeated, and the fourth example of UBAR2 is performed. The frequency response was recorded. This process involves several differences between the low and high acoustic impedance layers to characterize the frequency response of the fourth example of UBAR2 to different values of thickness of the low and high acoustic impedance layers. Repeated for thickness value. In some non-limiting embodiments or examples, the thickness of each low acoustic impedance layer and / or each high acoustic impedance layer may be the same or different. In some non-limiting embodiments or examples, diamond, SiC, W, Ir, AlN and the like can be used as high acoustic impedance materials. Frequency vs. amplitude plots, graphs, or relationships were calculated for each frequency sweep.

The fourth of UBAR2, shown in FIG. 13, with and without element layer 12, utilizing the frequency vs. amplitude plots, graphs, or relationships obtained for the frequency sweep of the fourth example of equations EQ2 and UBAR2. The optimum coupling efficiency M4CE for the mode 4 resonant frequency 88 of the example is, for example, for the piezoelectric layer 8 cut at an angle of 130 ° and, for example, each low acoustic impedance equal to (1/16) λ. For the thicknesses of layers 100, 104, and 108, and, for example, the thickness of each high acoustic impedance layer 102 and 106 equal to (1/16) λ, it was determined to be:
M4CE = 15.888% for values of f _p2 and f _s2 equal to 5.43 GHz and 5.08 GHz, respectively.

The aforementioned values of M4CE in this example may be appropriate and / or desirable, as values of M4CE of 3% or higher, 4% or higher, 6% or higher, 8% or higher, or 10% or higher may be satisfactory. It shall not be interpreted in a limited sense. In the example, the M4CE values of 3% and above, 4% and above, 6% and above, 8% and above, or 10% and above are ± appropriate and / or desirable values, eg, 130 ° ±, as described above. This can be achieved by adjusting the cut angle of the piezoelectric layer 8 by 30 °. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M4CE. May be sufficient for

In addition, the aforementioned thickness of each low acoustic impedance layer and / or each high acoustic impedance layer is any suitable and / or desirable thickness of each low acoustic impedance layer and / or thickness of each high acoustic impedance layer. May be an unlimited thickness of 1λ or less, (1/2) λ or less, (3/8) λ or less, (1/4) λ or less, or (1/8) λ or less. The thickness of each low and / or high acoustic impedance layer may differ (or be the same) as the thickness of any other low and / or high acoustic impedance layer and shall not be construed in a limited sense. .. Therefore, in the present specification, 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 high acoustic impedance layer (s) and the low acoustic impedance layer are the same. The same thickness (s) shall not be construed in a limited sense.

Fifth example of UBAR: Bending mode enabled by a stack with at least a low acoustic impedance layer and a high acoustic impedance layer and optionally having an element layer (mode 4).

Continuing with reference to FIGS. 11 and 13, in some non-limiting embodiments or examples, the piezoelectric layer 8 between 100 ° and 160 ° in a manner similar to the fourth example of UBAR2 described above. For each of several different cut angles, the frequency response (frequency vs. amplitude) is mostly used to model, except that the low acoustic impedance layer 108 is omitted: Illustrative added to the different thickness values of the low and high acoustic impedance layers of the fifth example of UBAR2, which is similar to the fourth example of UBAR2 (shown in FIG. 13) described above in terms of points. Frequency sweep of electrical stimulation (eg, from 1 GHz to 6.2 GHz) was determined. Frequency vs. amplitude plots, graphs, or relationships were calculated for each frequency sweep.

Using the frequency vs. amplitude plots, graphs, or relationships obtained for the fifth example of equations EQ2 and UBAR2, the mode 4 resonant frequency 88 of the fifth example of UBAR2 with and without element layer 12 Optimal coupling efficiency for M4CE is for the piezoelectric layer 8 cut at an angle of 130 °, and the thickness of each low acoustic impedance layer 100 and 104 equal to (1/16) λ and (1/16) λ. For the thickness of each high acoustic impedance layer 102 and 106 equal to, it was determined to be the same as in the fourth example of UBAR2, i.e. the following values.
M4CE = 15.888% for values of f _p2 and f _s2 equal to 5.43 GHz and 5.08 GHz, respectively.

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

The aforementioned values of M4CE in this example may be appropriate and / or desirable, as values of M4CE of 3% or higher, 4% or higher, 6% or higher, 8% or higher, or 10% or higher may be satisfactory. It shall not be interpreted in a limited sense. In the example, the M4CE values of 3% and above, 4% and above, 6% and above, 8% and above, or 10% and above are ± appropriate and / or desirable values, eg, 130 ° ±, as described above. This can be achieved by adjusting the cut angle of the piezoelectric layer 8 by 30 °. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M4CE. May be sufficient for

In addition, the aforementioned thickness of each low acoustic impedance layer and / or each high acoustic impedance layer is any suitable and / or desirable thickness of each low acoustic impedance layer and / or thickness of each high acoustic impedance layer. May be an unlimited thickness of 1λ or less, (1/2) λ or less, (3/8) λ or less, (1/4) λ or less, or (1/8) λ or less. The thickness of each low and / or high acoustic impedance layer may differ (or be the same) as the thickness of any other low and / or high acoustic impedance layer and shall not be construed in a limited sense. .. Therefore, in the present specification, 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 high acoustic impedance layer (s) is the low acoustic impedance. Being the same as the thickness of the layer (s) shall not be construed in a limited sense.

The result is that any additional benefit of one or more additional low-acoustic impedance layers between the high-acoustic impedance layer 106 and / or between the device layer 12 and / or the substrate 16 is available, if at all. Indicates that it may be negligible.

Sixth Example of UBAR: Bending mode (mode 4) enabled by a stack comprising at least a low acoustic impedance layer and a high acoustic impedance layer and optionally having an element layer. With reference to FIG. 14 and continuing with reference to FIG. 11, in some non-limiting embodiments or examples, a sixth example of UBAR2 formed of alternating layers of low and high acoustic impedance materials (Figure). (Shown in 14) extends from the piezoelectric layer 8 (formed of LiNbO ₃ crystals cut at an angle of about 130 ° (± 30 °, or ± 20 °, or ± 10 °)) to the element layer 12. 1. Low acoustic impedance layer 100, 1st high acoustic impedance layer 102, 2nd low acoustic impedance layer 104, 2nd high acoustic impedance layer 106, 3rd low acoustic impedance layer 108, and 1st The high acoustic impedance layer 110 of 3, the fourth low acoustic impedance layer 112, the fourth high acoustic impedance layer 114, the fifth low acoustic impedance layer 116, the fifth high acoustic impedance layer 118, and the third 6. Low acoustic impedance layer 120, 6th high acoustic impedance layer 122, 7th low acoustic impedance layer 124, 7th high acoustic impedance layer 126, 8th low acoustic impedance layer 128, The high acoustic impedance layer 130 of 8 and the 9th low acoustic impedance layer 132 can be included.

In this example, the spaced conductive wire or finger 20 or 28 of the top electrode 6 has a finger pitch 38 (shown in FIGS. 4A-4B) of 1.2 μm, a value of λ of 2.4 μm, and a piezoelectric wire. The thickness of the layers is (0.2) λ, the thickness of each low acoustic impedance layer is (1/16) λ, and the thickness of the element layer 12 is 4λ.

To model a sixth example of UBAR2 for each of several different cut angles of the piezoelectric layer 8 between 100 ° and 160 °, the frequency response is described above for the fourth example of UBAR2. Frequency sweep of the exemplary electrical stimulation added to the sixth example of UBAR2 (eg, 1 GHz to 6.2 GHz) for several different exemplary values of high acoustic impedance layer thickness in the manner described in. Up to). In this example, for each cut angle and each frequency sweep of the piezoelectric layer 8, each high acoustic impedance layer has the same thickness value. Frequency vs. amplitude plots, graphs, or relationships were calculated for each frequency sweep.

In some non-limiting embodiments or examples, each low acoustic impedance layer may be formed of silicon dioxide (SiO ₂ ) and each high acoustic impedance layer may be formed of, for example, aluminum nitride (AlN). The element layer 10 can be made of diamond or SiC, and the substrate 16 can be made of silicon.

Using the plots, graphs, or relationships of frequency responses obtained for the sixth example of equations EQ2 and UBAR2, the optimum coupling efficiency M4CE for mode 4 resonant frequency 88 of the sixth example of UBAR2 is 130 °. For the piezoelectric layer 8 cut at an angle of, and for the thickness of each high acoustic impedance layer equal to (5/16) λ, the following values were determined.
M4CE = 13.287% for values of f _p2 and f _s2 equal to 5.38 GHz and 5.09 GHz, respectively.

In some non-limiting embodiments 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 embodiments or examples, diamond, SiC, W, AlN and the like can be used as materials for each high acoustic impedance layer.

The aforementioned values of M4CE in this example may be appropriate and / or desirable, as values of M4CE of 3% or higher, 4% or higher, 6% or higher, 8% or higher, or 10% or higher may be satisfactory. It shall not be interpreted in a limited sense. In addition, the aforementioned thickness of each low acoustic impedance layer and / or each high acoustic impedance layer is any suitable and / or desirable thickness of each low acoustic impedance layer and / or thickness of each high acoustic impedance layer. May be an unlimited thickness of 1λ or less, (1/2) λ or less, (3/8) λ or less, (1/4) λ or less, or (1/8) λ or less. The thickness of each low and / or high acoustic impedance layer may differ (or be the same) as the thickness of any other low and / or high acoustic impedance layer and shall not be construed in a limited sense. .. Therefore, in the present specification, 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 high acoustic impedance layer (s) and the low acoustic impedance layer are the same. The same thickness (s) shall not be construed in a limited sense.

In the example, the M4CE values of 3% and above, 4% and above, 6% and above, 8% and above, or 10% and above are ± appropriate and / or desirable values, eg, 130 ° ±, as described above. This can be achieved by adjusting the cut angle of the piezoelectric layer 8 by 30 °. In some non-limiting embodiments or examples, the piezoelectric layer 8 such as a LiNbO ₃ crystal produced from a desired cut angle of Z-cut or X-cut, without limitation, obtains the desired specific value of M4CE. May be sufficient for

In some non-limiting embodiments or examples, the modeling of the first to sixth examples of UBAR2 described above is by computer simulation, optionally with respect to one or more physical samples. Was carried out.

It is described above that in some non-limiting embodiments or examples, the piezoelectric layer 8 formed of LiNbO ₃ cut at an angle of 130 ° or about 130 ° optimized the value of M4CE. It was determined from the models of the first to sixth examples of. However, it has also been determined that in some non-limiting embodiments or examples, the piezoelectric layer 8 formed of LiNbO ₃ cut at an angle between 100 ° and 160 ° also produced the desired value for M4CE. However, on the other hand, the piezoelectric layer 8 formed of LiNbO ₃ cut at an angle between 110 ° and 150 ° produces a more desirable value for M4CE and cuts at an angle between 120 ° and 140 °. The piezoelectric layer 8 formed of LiNbO ₃ produced an even more desirable value for M4CE. However, the piezoelectric layer 8 formed of LiNbO ₃ cut at an angle of 130 ° produced the most desirable (best) value of M4CE.

In any example of UBAR described herein, the thickness of the piezoelectric layer, such as LiNbO ₃ , is, in the example, 0.5λ or less, 0.4λ or less, 0.3λ or less, or in bending mode-mode 4. Any suitable and / or desired thickness, such as 0.2λ or less, may be used.

In any example of UBAR described herein, the thickness of the piezoelectric layer, such as LiNbO ₃ , is, in the example, 2λ or less, 1.6λ or less, 1.2λ or less, or 0.8λ in shear mode-mode 3. Any suitable and / or desired thickness may be used, such as:

In any example of UBAR described herein, for example, the thickness of electrodes such as Al, Mo, W may be 0.010λ or greater, 0.013λ or greater, 0.016λ or greater, 0.019λ or greater in the example. , Or any suitable and / or desired thickness, such as 0.022λ or greater.

In any suitable example of UBAR described herein, for example, the thickness of the element layer such as diamond, SiC, AlN may be any suitable, eg, 50 nm or more, 100 nm or more, 150 nm or more, or 200 nm or more. And / or the desired thickness.

In any example of UBAR described herein, the thickness of the low acoustic impedance layer is, in the example, 0.05λ or greater, 0.07λ or greater, 0.09λ or greater, 0.11λ or greater, or 0.13λ or greater. It may be any suitable and / or desired thickness such as.

In any example of UBAR described herein, the thickness of the high acoustic impedance layer is, in the example, 0.05λ or greater, 0.07λ or greater, 0.09λ or greater, 0.11λ or greater, or 0.13λ or greater. It may be any suitable and / or desired thickness such as.

In any example of UBAR described herein, the thickness of the temperature compensation layer is, in the example, optional, such as 2λ or less, 1.5λ or less, 1.0λ or less, 0.5λ or less, or 0.3λ or less. Appropriate and / or desired thickness of. Optionally, one or more or all of the outer surfaces of any example of UBAR described herein can be protected by an optional passivation layer. The passivation may be, for example, a layer of a dielectric material such as AlN, SiN, SiO ₂ .

The resonance frequency of any example of UBAR described herein may be 0.1 GHz or higher, 0.5 GHz or higher, 1.0 GHz or higher, 1.5 GHz or higher, or 2.0 GHz or higher.

The binding efficiency of any example of UBAR described herein may be 3% or higher, 4% or higher, 6% or higher, 8% or higher, or 10% or higher.

Any examples of UBAR described herein, a bulk acoustic wave, and S ₀ mode, extension mode, shear mode, A1 mode, shallow bulk acoustic wave including such bending mode may not be limited to, synthetic It can resonate in modes including modes.

Other non-limiting embodiments or examples are described in the numbered items below.

Item 1: bulk acoustic resonator includes a resonator body, the resonator body, and the piezoelectric layer is a LiNbO ₃ single crystal, and the element layer, and a top conductive layer on the piezoelectric layer opposite to the element layer Including, substantially all of the surface of the element layer on the side opposite to the piezoelectric layer is for mounting the resonator body on a carrier that is not a part of the resonator body.

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

Item 3: Bulk acoustic resonator of item 1 or 2, wherein the LiNbO ₃ single crystal may be cut at an angle of 0 ° ± 30 °, ± 20 °, or ± 10 °. vessel.

Item 4: The bulk acoustic resonator of any one of items 1 to 3 is in mode 3 or mode at a frequency of 0.1 GHz or more, 0.5 GHz or more, 1.0 GHz or more, 1.5 GHz or more, or 2.0 GHz or more. 4 resonances can be included.

Item 5: Mode 3 resonance in which any one of the bulk acoustic resonators of items 1 to 4 has a coupling efficiency of 8% or more, 11% or more, 14% or more, 17% or more, or 20% or more, and 3%. As described above, at least one of mode 4 resonance having a coupling efficiency of 4% or more, 6% or more, 8% or more, or 10% or more can be included.

Item 6: In the bulk acoustic resonator of any one of items 1 to 5, in mode 4 resonance, the LiNbO ₃ single crystal is 0.5λ or less, 0.4λ or less, 0.3λ or less, or 0.2λ. A bulk acoustic resonator that can have the following thickness.

Item 7: A bulk acoustic resonator according to any one of items 1 to 6, wherein in mode 3 resonance, the LiNbO ₃ single crystal is 2λ or less, 1.6λ or less, 1.2λ or less, or 0.8λ or less. A bulk acoustic resonator that can have a thickness.

Item 8: A conductive layer in which any one of the bulk acoustic resonators of items 1 to 7 has a thickness of 0.010λ or more, 0.013λ or more, 0.016λ or more, 0.019λ or more, or 0.022λ or more. Can be further included between the piezoelectric layer and the element layer.

Item 9: A bulk acoustic resonator according to any one of items 1 to 8, wherein the element layer can have a thickness of 50 nm or more, 100 nm or more, 150 nm or more, or 200 nm or more.

Item 10: The bulk acoustic resonator of any one of items 1 to 9 has an acoustic impedance between 10 ⁶ Pa · s / m ³ and 30 × 10 ⁶ Pa · s / m ³ and 0.05 λ or more, 0. A layer of low acoustic impedance material having a thickness of 07λ or more, 0.09λ or more, 0.11λ or more, or 0.13λ or more can be further included between the piezoelectric layer and the device layer.

Item 11: The bulk acoustic resonator of any one of items 1 to 10 has an acoustic impedance between 10 ⁶ Pa · s / m ³ and 630 × 10 ⁶ Pa · s / m ³ and 0.05 λ or more, 0. A layer of a high acoustic impedance material having a thickness of 07λ or more, 0.09λ or more, 0.11λ or more, or 0.13λ or more can be further included between the piezoelectric layer and the element layer.

Item 12: The bulk acoustic resonator of any one of items 1 to 11 has a thickness of 2λ or less, 1.5λ or less, 1.0λ or less, 0.5λ or less, or 0.3λ or less, and Si and oxygen. A temperature compensation layer containing the above can be further included between the piezoelectric layer and the element layer.

Item 13: The bulk acoustic resonator of any one of items 1 to 12 may further include a passivation layer.

Item 14: A bulk acoustic resonator according to any one of items 1 to 13, wherein the top conductive layer may include at least one pair of spaced conductive fingers. At least one pair of spaced conductive fingers can have a finger pitch of 70 μm or less, 20 μm or less, 10 μm or less, 6 μm or less, or 4 μm or less.

Item 15: The bulk acoustic resonator of any one of items 1 to 14 may further include a plurality of alternately overlapping temperature compensation layers and high acoustic impedance layers between the piezoelectric layer and the device layer.

Item 16: A bulk acoustic resonator according to any one of items 1 to 15, wherein the element layer is diamond; W; SiC; Ir, AlN, Al; Pt; Pd; Mo; Cr; Ti; Ta; elemental period. Elements of Group 3A or 4A in the table; transition elements of Group 1B, 2B, 3B, 4B, 5B, 6B, 7B or 8B in the Periodic Table of the Elements; ceramics; glass; and at least one of the polymers can be included. , Bulk acoustic resonator.

The present invention has been described in detail for illustration based on what is currently considered the most practical preferred and non-limiting embodiments, examples, or embodiments, but such details are for that purpose only. The present invention is not limited to the preferred and non-limiting embodiments, examples, or embodiments disclosed, and is intended to include modifications and equivalent configurations within the spirit and scope of the appended claims. Please understand that. For example, the present invention, wherever possible, features one or more of any preferred and non-limiting embodiments, examples, embodiments, or appended claims, any other preferred and non-limiting. It is to be understood that it is intended to be able to be combined with one or more features of various embodiments, examples, embodiments, or claims.

Claims (20)

It ’s a bulk acoustic resonator,
A resonator body is provided, and the resonator body is
A piezoelectric layer that is a LiNbO ₃ single crystal and
Element layer and
Including a top conductive layer on the piezoelectric layer on the opposite side of the element layer, substantially all of the surface of the element layer on the opposite side of the piezoelectric layer is a carrier that is not a part of the resonator body. A bulk acoustic resonator for mounting the resonator body. The bulk acoustic resonator according to claim 1, wherein the LiNbO ₃ single crystal is cut at an angle of 130 ° ± 30 °. The bulk acoustic resonator according to claim 1, wherein the LiNbO ₃ single crystal is cut at an angle of 130 ° ± 20 °. The bulk acoustic resonator according to claim 1, wherein the LiNbO ₃ single crystal is cut at an angle of 130 ° ± 10 °. The bulk acoustic resonator according to claim 1, wherein the LiNbO ₃ single crystal is cut at an angle of 0 ° ± 30 °. The bulk acoustic resonator according to claim 1, wherein the LiNbO ₃ single crystal is cut at an angle of 0 ° ± 20 °. The bulk acoustic resonator according to claim 1, wherein the LiNbO ₃ single crystal is cut at an angle of 0 ° ± 10 °. The bulk acoustic resonator according to claim 7, which comprises a mode 3 or mode 4 resonance at a frequency of 0.1 GHz or higher. Mode 3 resonance with a coupling efficiency of 8% or more,
The bulk acoustic resonator according to claim 1, further comprising at least one of a mode 4 resonance having a coupling efficiency of 3% or more. In mode 4 resonance, the LiNbO ₃ single crystal has a thickness of 0.5 λ or less, and the value of λ is based on the dimensions of the pattern or feature defined by the top conductive layer, or the LiNbO ₃ single crystal. 9. The bulk acoustic resonator according to claim 9. In mode 3 resonance, the LiNbO ₃ single crystal has a thickness of 2λ or less, and the value of λ is based on the dimensions of the pattern or feature defined by the top conductive layer, or the thickness of the LiNbO ₃ single crystal. The bulk acoustic resonator according to claim 9. A conductive layer having a thickness of 0.010 λ or more is further included between the piezoelectric layer and the device layer, and the value of λ is based on the dimensions of the pattern or feature defined by the top conductive layer, or the LiNbO. _3. The bulk acoustic resonator according to claim 1, which is based on the thickness of a single crystal. The bulk acoustic resonator according to claim 1, wherein the element layer has a thickness of 50 nm or more. A layer of a low acoustic impedance material having an acoustic impedance between 10 ⁶ Pa · s / m ³ and 30 × 10 ⁶ Pa · s / m ³ and a thickness of 0.05λ or more is formed between the piezoelectric layer and the element layer. The bulk acoustic resonator according to claim 1, wherein the value of λ is based on the dimensions of the pattern or feature defined by the top conductive layer, or based on the thickness of the LiNbO ₃ single crystal. A layer of a high acoustic impedance material having an acoustic impedance between 10 ⁶ Pa · s / m ³ and 630 × 10 ⁶ Pa · s / m ³ and a thickness of 0.05λ or more is formed between the piezoelectric layer and the element layer. The bulk acoustic resonator according to claim 1, wherein the value of λ is based on the dimensions of the pattern or feature defined by the top conductive layer, or based on the thickness of the LiNbO ₃ single crystal. A temperature compensating layer having a thickness of 2λ or less and containing Si and oxygen is further included between the piezoelectric layer and the device layer, and the value of λ is based on the dimensions of the pattern or feature defined by the top conductive layer. Or the bulk acoustic resonator according to claim 1, which is based on the thickness of the LiNbO ₃ single crystal. The bulk acoustic resonator according to claim 1, further comprising a passivation layer. The bulk acoustic resonator according to claim 1, wherein the top conductive layer comprises at least one pair of spaced conductive fingers. The bulk acoustic resonator according to claim 1, further comprising a plurality of alternately overlapping temperature compensation layers and high acoustic impedance layers between the piezoelectric layer and the element layer. The element layer is diamond; W; SiC; Ir, AlN, Al; Pt; Pd; Mo; Cr; Ti; Ta; elements of Group 3A or 4A in the periodic table of elements; 1B, 2B, 3B in the periodic table of elements, The bulk acoustic resonator according to claim 1, which comprises at least one of a group 4B, 5B, 6B, 7B or 8B transition element; ceramic; glass; and a polymer.

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