English:
[0001] This relates generally to bulk acoustic wave (BAW) resonators, and more particularly to BAW resonators having a phononic crystal (PnC) acoustic mirror (PCAM).
[0002] In BAW resonators, electrodes (e.g., contacts, metal patches, etc.) on top and bottom surfaces of a layer of piezoelectric material excite acoustic waves in the piezoelectric material. Bulk acoustic waves of specific frequencies are generated within a resonant cavity forming a resonant response.
[0003] An example integrated circuit package includes a bulk acoustic wave (BAW) resonator including a phononic crystal acoustic mirror (PCAM). The PCAM includes a first arrangement of first members in a first region, and a second arrangement of second members in a second region. The first arrangement is different from the second arrangement.
[0004] FIG. 1 is a side cross-section view of an example IC package including an example BAW resonator having an example PCAM, constructed according to this description.
[0005] FIG. 2 is a perspective view of an example arrangement that may be used to implement the example PCAMs described herein.
[0006] FIG. 3 is a side cross-section view of another example IC package including an example BAW resonator having another PCAM, constructed according to this description.
[0007] FIG. 4 is a side cross-section view of yet another example IC package including an example BAW resonator having yet another example PCAM, constructed according to this description.
[0008] The drawings are not to scale. For example, to clarify multiple layers and regions, the thickness of the layers may be enlarged in the drawings. Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. If this description states that a part (e.g., a layer, film, area, or plate) is in any way positioned on (e.g., positioned on, located on, disposed on, or formed on, deposited on, etc.) another part, then it means that the referenced part is either in contact with the other part, or that the referenced part is above the other part with one or more intermediate part(s) located therebetween. Also, if this description states that a part is in contact with another part, then it means that no intermediate part is between the two parts. Further, in this description, terms such as up, down, top, bottom, side, end, front, back, etc. are used with reference to a currently considered or illustrated orientation. If a different orientation is considered, then such terms should be correspondingly modified. In the drawings, connecting lines or connectors represent example functional relationships and/or physical or logical couplings between the various elements.
[0009] The performance of electrical devices, such as modern wireless communication devices, depends heavily on the accuracy and noise level of the clock signals used in a system. Such systems necessarily need high-frequency, and high quality factor (Q) resonators. Q is a dimensionless parameter that reflects the under-damping of an oscillator, and characterizes a resonator's bandwidth relative to its center frequency. The Q of known BAW resonators are 10 to 100 times lower than the intrinsic limitations of the piezoelectric material. To improve the performance of BAW resonators, example BAW resonators including a phononic crystal (PnC) acoustic mirror (PCAM) are described herein. Because described example PCAMs confine the propagation of acoustic energy, more acoustic energy is retained in the active region of the BAW resonator. The increase in retained acoustic energy increases the Q of the BAW resonator, and, in turn, the performance of a system including the BAW resonator.
[0010] FIG. 1 is a side cross-section view of an example IC package 100 (e.g., a semiconductor-based device, chip, etc.) having an example BAW resonator 102 disposed in the example IC package 100. The example IC package 100 of FIG. 1 is a surface mount device with a plurality of contacts (an example of which is designated at reference numeral 106) on a bottom side 108. However, the example IC package 100 may be of any type, and may have any form, material(s), shape, dimension(s), number of contacts, shape of contacts, etc. In some examples, the IC package 100 is a wafer-level package, or a die-level package. The BAW resonator 102 and/or any other components may be integrated, etc. with other circuits (e.g., an example IC 104) and/or passive components, or by itself, and packaged in an IC package (e.g., the example IC package 100) in any way. Example ICs 104 include a digital logic circuit, an analog circuit, a processor core, a digital signal processor (DSP) core, etc.
[0011] The example BAW resonator 102 of FIG. 1 includes a layer of piezoelectric material 110 disposed on (e.g., deposited on, formed on, etc.) an example bottom electrode 112, and an example top electrode 114 disposed on (e.g., deposited on, formed on, etc.) the layer of piezoelectric material 110 opposite the bottom electrode 112. In operation, when a voltage is applied between the top electrode 114 and the bottom electrode 112, bulk acoustic waves of specific frequencies are generated within the resonator stack (112, 110, 114), forming a resonance response. For example, the resonant response may be used to generate a clock signal, a carrier signal, etc.
[0012] In the example of FIG. 1, the bottom electrode 112, the layer of piezoelectric material 110, and the top electrode 114 are planar structures, but they may be formed to have other shapes. Moreover, the bottom electrode 112, the layer of piezoelectric material 110, and the top electrode 114 are not required to have the same dimensions or shape. In the case of a semiconductor-based IC package, the example layer of piezoelectric material 110 may include a piezoelectric material compatible with a semiconductor manufacturing process, such as aluminum nitride and zinc oxide. In some examples, the BAW resonator 102 is built on a sacrificial layer (the substrate will be released later) to form a free-standing thin-film resonator. In other examples, the BAW resonator 102 is built on one or more acoustic reflectors (Bragg reflectors) to form a solidly mounted resonator.
[0013] To increase retention of acoustic energy in the BAW resonator 102, the example BAW resonator 102 includes an example Bragg mirror 116 (a.k.a. an acoustic mirror, an acoustic reflector, etc.), an example PC AM 118, and an example PC AM 120. The example Bragg mirror 116 of FIG. 1 reduces acoustic energy leakage through the bottom of the BAW resonator 102. Any known or future Bragg mirror, acoustic mirror, acoustic reflector, etc. may be used to implement the Bragg mirror 116. The example Bragg mirror 116 of FIG. 1 includes alternating layers of materials with different acoustic impedance. In some examples, the Bragg mirror 116 includes flat metal members (e.g., membranes, layers, sheets, plates, etc.), two of which are designated at reference numerals 122 and 124, spaced apart and disposed in a dielectric material 126. The thickness(es) of and distances between the metal members 122, 124 are selected, based on an intended resonant frequency of the BAW resonator 102, to cause constructive interference at that frequency, resulting in the Bragg mirror 116 reducing spurious modes, and confining (e.g., reflecting, directing, containing, etc.) at least some main mode acoustic energy at that frequency in a resonant cavity portion 128 of the BAW 102. In some examples, confining main mode acoustic energy refers to confining a portion of main mode acoustic energy. Thus, retention of acoustic energy at the intended resonant frequency in the BAW resonator 102 is increased, and the Q of the BAW resonator 102 is increased, and, in turn, the performance of a system including the example BAW 102 and/or the example IC package 100 is increased. In the case of a semiconductor-based IC package, the example electrodes 112 and 114 are formed of a conductive material compatible with a CMOS manufacturing process. In some examples, the metal members 122, 124 include tungsten (W), titanium tungsten (TiW), or copper (Cu), and the dielectric material 126 includes silicon dioxide (Si02), or a carbon doped oxide dielectric, such as SiCOH. In some examples, the thickness of the members 122, 124 is one-fourth the wavelength of a wave of interest in the material. For example, for a 5GHz resonator, the wavelength of the p-wave is 1.02μπι for W, and 1.18μπι for Si02, corresponding to respective thicknesses of 255nm and 295nm.
[0014] The example PCAM 118 of FIG. 1 reduces acoustic energy leakage through the left end of the BAW resonator 102, and the example PCAM 120 of FIG. 1 reduces acoustic energy leakage through the right end of the BAW resonator 102. The PCAM 118 extends laterally from the Bragg mirror 116 to the left, and the PCAM 120 extends laterally from the Bragg mirror 116 to the right. Because the PCAMs 118 and 120 (and other example PCAMs described hereinbelow) reduce acoustic energy leakage through their respective ends of the BAW resonator 102, the costly and complex processes needed to form a guard ring on the top electrode 114 for known BAW resonators can be eliminated. Because the example PCAM 120 is implemented similarly to the PCAM 118, refer to the description of the PCAM 118 for a description of the PCAM 120.
[0016] The dimension(es) of and distance(s) (one of which is designated at reference numeral 133) between the members 130-132 are selected, such as using Bloch's Theorem, or known or future methods developed based on Bloch's Theorem. The dimension(es) of and distance(s) are selected, based on an intended resonant frequency of the BAW resonator 102 and potential angle of acoustic energy leakage, to form phononic band gaps that prevent acoustic signals at the intended resonant frequency from passing through PCAM 118. Thus, retention of acoustic energy at the intended resonant frequency in the BAW resonator 102 is increased, and the Q of the BAW resonator 102 is increased.
[0017] In some examples, the PCAM 118 and the PCAM 120 are designed to confine at least some main mode acoustic energy that is emitted from the BAW 102 on angles (one of which is designated at reference numeral 134). In some examples, the example Bragg mirror 116 implements a one-dimensional (ID) PCAM formed by an arrangement of a plurality of members (the members 122 and 124)) to implement a desired pattern of variations in one or more acoustic properties (e.g., reflect acoustic energy at a desired frequency). The PCAM 118 and the PCAM 120 have different arrangements of members than the Bragg mirror 116, and, thus, implement different variations in acoustic properties. The example Bragg mirror 116 confines at least some main mode acoustic energy that is emitted downward from the BAW 102. By implementing the BAW 102 with the Bragg mirror 116 (e.g., parallel horizontal flat members 122, 124), the PCAM 118 (e.g., 2D arrangement of elongated members 130-132) and PCAM 120, which have different arrangements of members, a virtual reflector 136 is implemented. The virtual reflector 136, at least in part, reduces spurious modes, and confines main mode acoustic energy in the resonant cavity portion 128 of the BAW resonator 102 for a wider range of angles (e.g., more than just downward) than is realized in known acoustic resonators.
[0018] In some examples, the members 130-132 of the PCAMs 118 and 120 (and those of additional example PCAMs described hereinbelow) are used to implement feature dummies used during a chemical-mechanical polishing (CMP) process to reduce the likelihood of recesses forming in a surface during polishing. Because the members 130-132 are already included to reduce acoustic leakage, their additional use as CMP feature dummies obviates the complexity and cost of implementing conventional CMP feature dummies. The use of CMP enables a flatter piezoelectric layer, which, in turn, reduces scattering and spurious emissions. A flatter piezoelectric layer 110 can allow thicker layers (e.g., the piezoelectric layer 110) to be formed, thereby allowing lower resonant frequencies without necessarily introducing steps, coverage and/or cracking issues at the edges.
[0019] The bottom electrode 112 and the top electrode 114 may be electrically coupled with other components in the IC package 100 (e.g., the example IC 104) and/or external components. For example, the top electrode 112 may be electrically connected wire bonded (shown schematically by a line 138 in FIG. 1) to the example IC 104 implemented in the IC package 100. In some examples, the IC 104 controls and/or uses a clock signal generated using the BAW resonator 102 to perform one or more functions (e.g., down conversion, up conversion, modulation, de-modulation, etc.). The IC 104, the bottom electrode 112 and/or the top electrode 114 may be electrically coupled (connected etc.) to an external contact (e.g., the example contact 106), as shown schematically in FIG. 1 with a line 140. In the example of FIG. 1, the BAW resonator 102 is disposed on (e.g., deposited on, formed on, etc.) an example substrate 142, an acoustic reflector, a sacrificial layer, etc. In some examples, the IC 104 is an IC die, and the BAW resonator 102 is a microelectromechanical system (MEMS) die.
[0020] FIG. 3 is a side cross-section view of another example IC package 300 having a BAW resonator 302 including another example PCAM 304, in accordance with this description. Identical parts, structures, arrangements, etc. shown in FIG. 1 and FIG. 3 have the same reference numbers in FIGS. 1 and 3. The accompanying written descriptions are not repeated here, so refer to the written descriptions hereinabove in connections with FIG. 1 for those identical parts, structures, arrangements, etc.
[0021] In the example of FIG. 3, the Bragg mirror 116, the PCAM 118 and the PCAM 120 of FIG. 1 are replaced by the example multiple region PCAM 304. The example multi-region PCAM 304 of FIG. 3 reduces acoustic energy leakage through the bottom, the left end, and the right end of the BAW resonator 302. The example PCAM 304 of FIG. 3 includes a plurality of members (five of which are designated at reference numerals 306, 307, 308, 309 and 310) that are arranged in an ordered pattern. The ordered pattern of the members 306-310 implements an ordered pattern of variations in the acoustic properties of the PCAM 304. Like that shown in FIG. 2, the members 306-310 extend longitudinally into the dielectric material 126. In the example of FIG. 3, the variations in acoustic properties of the PCAM 304 are two-dimensional (2D), occurring along the x-axis and the z-axis. However, for example, a three-dimensional (3D) PCAM may be implemented when acoustic signal energy occurs along the y-axis. Rectangular shapes are shown in FIG. 3, but other shapes (such as cylinders, triangles, etc.) may be implemented. Other arrangements (such as lattices) can be implemented. In some examples, the members 306-310 are replaced with hollow areas (e.g., regions, portions, etc.) of the dielectric material 126. For example, each of the members 306-310 could be replaced with a hollow cylindrical area that passes at least part way through the dielectric material 126.
[0022] The example multi-region PCAM 304 of FIG. 3 includes five example regions 312, 313, 314, 315 and 316. As shown, each of the regions 312-316 includes one or more of the plurality of the members 306-310. As shown, the regions 312-316 can have a different number of regions, a different number of members, different shaped members, members of different sizes, different distances between members, different arrangements of members, etc. In some examples, the regions 312-316 are implemented to reduce acoustic energy leakage of different modes (longitudinal, shear modes etc.) at different angles for different portions of the BAW resonator 302. For example, acoustic energy leaking downward in a middle portion of the BAW resonator 302, and increasingly becoming more horizontal as the distance from the end of the bottom electrode 112 increases. In an example, to reduce acoustic energy leakage through the bottom of the BAW resonator 302, the example region 312 includes members (one of which is designated at reference numeral 306) that are selected and arranged (e.g., smaller and spaced closer together by a distance Dl) to block acoustic energy that is mainly perpendicular to the region 306. To reduce acoustic energy leakage on a downward and outward direction 318 from the BAW resonator 302, the example region 313 includes members (one of which is designated at reference numeral 307) that are selected and arranged (e.g., larger and spaced further apart by a larger distance D2) to block acoustic energy that impinges the region 313 at the angles 318. To reduce acoustic energy leakage on a shallower outward direction 320 from the BAW resonator
[0023] As described hereinabove, the dimension(es) and arrangement(s) of the members 306-310 for the regions 312-316 can be selected based on Bloch's Theorem, an intended resonant frequency of the BAW resonator 302, and an anticipated angle of acoustic energy leakage, to form phononic band gaps that increase retention of acoustic energy at the intended resonant frequency in the BAW resonator 302, and the Q of the BAW resonator 302 is increased.
[0024] FIG. 4 is a side cross-section view of another example IC package 400 having a BAW resonator 402 including yet another example PCAM 404, in accordance with this description. Identical parts, structures, arrangements, etc. shown in FIG. 1, FIG. 3 and FIG. 4 have the same reference numbers in FIGS. 1, 3 and 4. The accompanying written descriptions are not repeated here, so refer to the written descriptions hereinabove in connections with FIGS. 1 and 3 for those identical parts, structures, arrangements, etc.
[0025] In the example FIG. 4, the example multi-region PCAM 404 extends the example multi -region PCAM 304 of FIG. 3 with additional members (three of which are designated at reference numerals 408, 409 and 410). A portion of the additional members 408-410 are on the same layer of the BAW resonator 402 as the bottom electrode 112, and another portion are on the same layer of the BAW resonator 402 as the top electrode 114. In some examples, additional members 408-410 are shaped and dimensioned to correspond to the member 306-310 below the additional member 408-410. The additional members 408-410 may be implemented on one end of the BAW resonator 402, as shown, or both ends. In some examples, the members 408-410 are formed of the same materials as the electrodes 112 and 114, and formed (e.g., deposited) at the same time that the electrodes 112 and 114 are formed. They can also be formed of the same material as the members 306-310. The members 408-410 can be selected and arranged together with the members 306-310 based on Bloch's Theorem, an intended resonant frequency of the
[0026] FIGS. 1-4 show example ways of implementing IC packages 100, 300, and 400 including a BAW resonator 102, 302, 402 having a PCAM in accordance with example embodiments, but one or more of the parts, structures, arrangements, etc. illustrated in FIGS. 1-4 may be combined, divided, rearranged, omitted, eliminated and/or implemented in any other way. Further, an IC package including a BAW resonator having a PCAM in accordance with this description may include one or more parts, structures, arrangements, etc. in addition to, and/or instead of, those illustrated in FIGS. 1-4, and/or may include more than one of any or all of the illustrated parts.
[0027] Any references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
[0028] Modifications are possible in the described embodiments, and other embodiments are possible, within the scope of the claims.

中文:
[0001]本文总体上涉及体声波(BAW)谐振器,并且更具体地涉及具有声子晶体(PnC)声学镜(PCAM)的BAW谐振器。
[0002]在BAW谐振器中,压电材料层的顶部表面和底部表面上的电极(例如,触点、金属补片等)激发压电材料中的声波。在谐振腔内生成特定频率的体声波,从而形成谐振响应。
[0003]示例集成电路封装件包括体声波(BAW)谐振器,该体声波谐振器包括声子晶体声学镜(PCAM)。PCAM包括第一区域中的第一构件的第一布置和第二区域中的第二构件的第二布置。第一布置不同于第二布置。
[0004]图1是示例IC封装件的侧面剖视图,该示例IC封装件包括示例BAW谐振器,该示例BAW谐振器具有根据本说明书构造的示例PCAM。
[0005]图2是可用于实现本文所述的示例PCAM的示例布置的透视图。
[0006]图3是另一示例IC封装件的侧面剖视图,该另一示例IC封装件包括示例BAW谐振器,该示例BAW谐振器具有根据本说明书构造的另一PCAM。
[0007]图4是又一示例IC封装件的侧面剖视图,该又一示例IC封装件包括示例BAW谐振器,该示例BAW谐振器具有根据本说明书构造的又一示例PCAM。
[0008]附图未按比例绘制。例如,为了阐明多个层和区域,在附图中可将层的厚度放大。只要有可能,相同的附图标记将用于整个附图和所附书面描述中用来指代相同或类似的部件。如果本说明书陈述一个部件(例如,层、膜、区域或板)以任何方式定位(例如,定位、位于、设置、或形成、堆积等)于另一部件上,则这意指涉及的部件与另一部件接触,或者涉及的部件在一个或多个中间部件位于其间的情况下位于另一部件上方。同样,如果本说明书陈述一个部件与另一部件接触,则这意指没有中间部件位于这两个部件之间。另外,在本说明书中,术语诸如上、下、顶部、底部、侧面、端部、前部、背部等用于参照当前考虑或例示的取向。如果考虑不同的取向,则应该对此类术语进行相应地修改。在附图中,连接线或连接符表示各种元件之间的示例功能关系和/或物理或逻辑耦合。
[0009]电气装置(诸如现代无线通信装置)的性能很大程度上取决于系统中所使用的时钟信号的精确度和噪声水平。此类系统必然需要高频率和高品质因数(Q)谐振器。Q是反映振荡器的阻尼不足并且表征谐振器相对于其中心频率的带宽的无量纲参数。已知BAW谐振器的Q是压电材料的内在限制的10至100分之一。为改善BAW谐振器的性能,本文描述了包括声子晶体(PnC)声学镜(PCAM)的示例BAW谐振器。因为所述示例PCAM限制声学能量的传播,所以更多声学能量保留在BAW谐振器的有效区域中。保留的声学能量的增加增加了BAW谐振器的Q,并且继而增加包括BAW谐振器的系统的性能。
[0010]图1是示例IC封装件100(例如,基于半导体的装置、芯片等)的侧面剖视图,该示例IC封装件具有设置在示例IC封装件100中的示例BAW谐振器102。图1的示例IC封装件100为具有位于底部侧108上的多个触点(其示例在附图标记106处标明)的表面安装装置。然而,示例IC封装件100可为任何类型的封装件,并且可具有任何形式、(一种或多种)材料、(一个或多个)尺寸、触点数目、触点形状等。在一些示例中,IC封装件100为晶片级封装件或管芯级封装件。BAW谐振器102和/或任何其他器件可与其他电路(例如,示例IC 104)和/或无源器件等或与其自身集成等,并且可以以任何方式封装在IC封装件(例如,示例IC封装件100)中。示例IC 104包括数字逻辑电路、模拟电路、处理器核心、数字信号处理器(DSP)核心等。
[0011]图1的示例BAW谐振器102包括设置(例如,沉积、形成等)在示例底部电极112上的压电材料层110,和设置(例如,沉积、形成等)在该压电材料层110上与底部电极112相对的示例顶部电极114。在操作时,当将电压施加于顶部电极114和底部电极112之间时,在谐振器堆叠(112、110、114)内生成特定频率的体声波,从而形成谐振响应。例如,该谐振响应可用于生成时钟信号、载波信号等。
[0012]在图1的示例中,虽然底部电极112、压电材料层110和顶部电极114为平面结构,但是它们可以被形成为具有其他形状。此外,底部电极112、压电材料层110和顶部电极114不需要具有相同的尺寸或形状。在基于半导体IC封装件的情况下,示例压电材料层110可包含与半导体制造工艺兼容的压电材料,诸如氮化铝和氧化锌。在一些示例中,BAW谐振器102构建于牺牲层上(稍后将释放衬底)以形成独立式薄膜谐振器。在其他示例中,BAW谐振器102构建于一个或多个声学反射器(布拉格反射器)上以形成牢固安装的谐振器。
[0013]为增加BAW谐振器102中的声学能量保留,示例BAW谐振器102包括示例布拉格镜116(又称声学镜、声学反射器等)、示例PCAM 118和示例PCAM120。图1的示例布拉格镜116减少了通过BAW谐振器102的底部的声学能量泄露。可使用任何已知的或未来的布拉格镜、声学镜、声学反射器等来实现布拉格镜116。图1的示例布拉格镜116包括具有不同的声学阻抗的交替的材料层。在一些示例中,布拉格镜116包括平坦的金属构件(例如,隔膜、层、片材、板材等),这些金属构件中的两个在附图标记122和124处标明,用介电材料126间隔开并设置在该介电材料中。基于BAW谐振器102的预期谐振频率选择金属构件122、124的(一个或多个)厚度和其间的距离,以导致在该频率下的相长干涉,从而使布拉格镜116减小副振荡模,并且将该频率下的至少一些主模声学能量限制(例如,反射、引导、容纳等)在BAW 102的谐振腔体部分128中。在一些示例中,限制主模声学能量是指限制主模声学能量的一部分。因此,增加了BAW谐振器102中的预期谐振频率下的声学能量保留,并且增加了BAW谐振器102的Q,并且继而增加了包括示例BAW102和/或示例IC封装件100的系统的性能。在基于半导体的IC封装件的情况下,示例电极112和114由与CMOS制造工艺兼容的导电材料形成。在一些示例中,金属构件122、124包含钨(W)、钛钨(TiW)或铜(Cu),并且介电材料126包含二氧化硅(SiO2)或碳掺杂的介电氧化物,诸如SiCOH。在一些示例中,构件122、124的厚度是材料中感兴趣的波的波长的四分之一。例如,对于5GHz谐振器而言,W的p波的波长是1.02μm,并且SiO2的p波的波长是1.18μm,对应于255nm和295nm的相应厚度。
[0014]图1的示例PCAM 118减少通过BAW谐振器102的左端部的声学能量泄露,并且图1的示例PCAM 120减少通过BAW谐振器102的右端部的声学能量泄露。PCAM 118从布拉格镜116侧向延伸至左侧,并且PCAM 120从布拉格镜116侧向延伸至右侧。由于PCAM 118和120(和下文所述的其他示例PCAM)减少了通过BAW谐振器102的其相应端部的声学能量泄露,所以,可消除在已知的BAW谐振器的顶部电极114上形成护环所需要的昂贵且复杂的工艺。由于类似于PCAM 118来实现示例PCAM 120,所以参照PCAM 118的描述来描述PCAM 120。
[0016]选择构件130-132的(一个或多个)尺寸和(一个或多个)其间的距离(其中之一在附图标记133处标明),诸如使用布洛奇定理或基于布洛奇定理开发的已知的或未来的方法进行选择。基于BAW谐振器102的预期谐振频率和声学能量泄露的潜在角度,选择该(一个或多个)尺寸和(一个或多个)距离,以形成声子带隙,该声子带隙防止预期谐振频率下的声学信号通过PCAM118。因此,增加了BAW谐振器102中的预期谐振频率下的声学能量保留,并且增加了BAW谐振器102的Q。
[0017]在一些示例中,PCAM 118和PCAM 120被设计为限制从BAW 102以一定角度(其中之一在附图标记134处标明)发射的至少一些主模声学能量。在一些示例中,示例布拉格镜116实现由多个构件(构件122和124)的布置形成的一维(1D)PCAM,以实现一个或多个声学特性变型(例如,期望频率下的反射声学能量)的期望图案。PCAM 118和PCAM 120与布拉格镜116相比具有不同的构件布置,并且因此实现不同的声学特性变型。示例布拉格镜116限制从BAW 102向下发射的至少一些主模声学能量。通过利用布拉格镜116(例如,平行水平平坦构件122、124)、PCAM 118(例如,细长构件130-132的2D布置)和PCAM 120(其具有不同的构件布置)来实现BAW 102,实现了虚拟反射器136。虚拟反射器136至少部分地减小了副振荡模,并且针对比在已知的声学谐振器中实现的更宽范围的角度(例如,不止仅仅向下)将主模声学能量限制在BAW谐振器102的谐振腔体部分128中。
[0018]在一些示例中,PCAM 118和120的构件130-132(和下文所述的附加示例PCAM的构件)用于实现在化学机械抛光(CMP)工艺期间使用的特征模拟,以降低在抛光期间在表面中形成凹槽的可能性。由于构件130-132已经包括在内用于减少声学泄露,所以其作为CMP特征模拟的附加用途避免了实现常规CMP特征模拟的复杂性和成本。CMP的使用实现较平坦的压电层,这继而降低了散射和杂散发射。较平坦的压电层110可允许形成较厚的层(例如,压电层110),从而允许较低的谐振频率而不会在边缘处不必要地引入步进、覆盖和/或断裂问题。
[0019]底部电极112和顶部电极114可以与IC封装件100(例如,示例IC 104)中的其他器件和/或外部器件电耦合。例如,顶部电极112可电连接引线键合(由图1中的线138示意性地示出)至IC封装件100中实现的示例IC 104。在一些示例中,IC 104控制和/或使用通过使用BAW谐振器102生成的时钟信号来执行一个或多个功能(例如,下变换/下变频、上变换/上变频、调制、解调等)。IC 104、底部电极112和/或顶部电极114可电耦合(连接等)至外部触点(例如,示例触点106),如图1用线140示意性地示出。在图1的示例中,BAW谐振器102设置(例如,沉积、形成等)在示例衬底142、声学反射器、牺牲层等上。在一些示例中,IC 104为IC管芯,并且BAW谐振器102为微机电系统(MEMS)管芯。
[0020]图3是另一示例IC封装件300的侧面剖视图,该另一示例IC封装件具有BAW谐振器302,该BAW谐振器包括根据本说明书的另一示例PCAM 304。图1和图3中示出的相同部件、结构、布置等在图1和图3中具有相同的附图标记。此处不再重复所附书面描述,因此那些相同的部件、结构、布置等参照结合图1的上面的书面描述。
[0021]在图3的示例中,图1的布拉格镜116、PCAM 118和PCAM 120由示例多个区域PCAM304代替。图3的示例多区域PCAM 304减少了通过BAW谐振器302的底部、左端部和右端部的声学能量泄露。图3的示例PCAM 304包括以有序图案布置的多个构件(其中五个在附图标记306、307、308、309和310处标明)。构件306-310的有序图案实现PCAM 304的声学特性中的变型的有序图案。如同图2中所示,构件306-310纵向延伸到介电材料126中。在图3的示例中,PCAM 304的声学特性中的变型是二维的(2D),沿x轴和z轴发生。然而,例如,三维(3D)PCAM可在声学信号能量沿y轴发生时实现。虽然在图3中示出矩形形状,但是可实现其他形状(诸如圆柱形、三角形等)。可实现其他布置(诸如格子)。在一些示例中,用介电材料126的中空区(例如,区域、部分等)代替构件306-310。例如,构件306-310中的每个可用至少部分穿过介电材料126的中空圆柱区代替。
[0022]图3的示例多区域PCAM 304包括五个示例区域312、313、314、315和316。如图所示,区域312-316中的每个包括多个构件306-310中的一个或多个。如图所示,区域312-316可具有不同的区域数目、不同的构件数目、不同形状的构件、不同大小的构件、不同的构件间距离、不同的构件布置等。在一些示例中,区域312-316被实现为减小BAW谐振器302的不同部分在不同角度处的不同模式(纵向模式、剪切模式等)的声学能量泄露。例如,在BAW谐振器302的中部中声学能量向下泄露,并且随着距底部电极112的端部的距离增大而逐渐变得更加水平。在一个示例中,为减小通过BAW谐振器302的底部的声学能量泄露,示例区域312包括这样的构件(其中之一在附图标记306处标明),该构件被选择和布置(例如,较小的并且一起较紧密地隔开距离D1)成阻挡主要垂直于区域306的声学能量。为减小在从BAW谐振器302向下且向外方向318上的声学能量泄露,示例区域313包括这样的构件(其中之一在附图标记307处标明),该构件被选择和布置(例如,较大的并且较远地隔开较大距离D2)成阻挡以角度318冲击区域313的声学能量。为减小在从BAW谐振器302较浅的向外方向320上的声学能量泄露,示例区域315包括这样的构件(其中之一在附图标记309处标明),该构件被选择和布置(例如,甚至更大并且甚至更远地隔开较大距离D3)成阻挡以较浅角度320冲击区域315的声学能量。通过利用具有不同的构件布置的不同区域312-316来实现PCAM,实现了虚拟反射器322。虚拟反射器322至少部分地减小了副振荡模,并且针对比在已知的声学谐振器中实现的更宽范围的角度(例如,不止仅仅向下)将主模声学能量限制在BAW谐振器302的谐振腔体部分中。
[0023]如上文所述,可基于布洛奇定理、BAW谐振器302的预期谐振频率和声学能量泄露的期望的角度选择区域312-316的构件306-310的(一个或多个)尺寸和(一个或多个)布置,以形成声子带隙,该声子带隙增加了BAW谐振器302中预期谐振频率下的声学能量保留,并且增加了BAW谐振器302的Q。
[0024]图4是另一示例IC封装件400的侧面剖视图,该另一示例IC封装件具有BAW谐振器402,该BAW谐振器包括根据本说明书的又一示例PCAM 404。图1、图3和图4中示出的相同部件、结构、布置等在图1、图3和图4中具有相同的附图标记。此处不再重复所附书面描述,因此那些相同的部件、结构、布置等参照结合图1和图3的上面的书面描述。
[0025]在图4的示例中,示例多区域PCAM 404以附加构件(其中三个在附图标记408、409和410处标明)扩展图3的示例多区域PCAM 304。附加构件408-410的一部分与底部电极112位于BAW谐振器402的同一层上,并且另一部分与顶部电极114位于BAW谐振器402的同一层上。在一些示例中,附加构件408-410的形状和尺寸被设计为对应于附加构件408-410下方的构件306-310。附加构件408-410可以实现于BAW谐振器402的一个端部(如图所示)或两个端部上。在一些示例中,构件408-410由与电极112和114相同的材料形成,并且在形成电极112和114的相同时间形成(例如,沉积)。它们也可由与构件306-310相同的材料形成。构件408-410可以与构件306-310一起基于布洛奇定理、BAW谐振器402的预期谐振频率和声学能量泄露的期望角度进行选择和布置,以形成声子带隙,该声子带隙增加了BAW谐振器402中预期谐振频率下的声学能量保留,并且增加了BAW谐振器402的Q。
[0026]虽然图1-图4示出根据示例实施例的实现包括具有PCAM的BAW谐振器102、302、402的IC封装件100、300和400的示例方式,但是可以以任何其他方式组合、分割、重新布置、省略、消除和/或实现图1-图4中例示的部件、结构、布置等中的一个或多个。另外,根据本说明书的包括具有PCAM的BAW谐振器的IC封装件可包括除了图1-图4中例示的那些之外和/或代替图1-图4中例示的那些的一个或多个部件、结构、布置等,并且/或者可包括例示部件的任何部件或全部部件中的多于一者。
[0027]本文引用的任何参考文献(包括公布、专利申请和专利)以犹如通过引用单独地且具体地指出每种参考文献被并入并且在本文以其全文提出的相同程度通过引用据此并入本文。
[0028]在权利要求的范围内,所述实施例中的修改是可能的,并且其他实施例也是可能的。