WO2024001352A1 - 具有温度补偿特性的声波器件结构、滤波器和电子设备 - Google Patents

具有温度补偿特性的声波器件结构、滤波器和电子设备 Download PDF

Info

Publication number
WO2024001352A1
WO2024001352A1 PCT/CN2023/084455 CN2023084455W WO2024001352A1 WO 2024001352 A1 WO2024001352 A1 WO 2024001352A1 CN 2023084455 W CN2023084455 W CN 2023084455W WO 2024001352 A1 WO2024001352 A1 WO 2024001352A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
temperature compensation
acoustic wave
device structure
resonant
Prior art date
Application number
PCT/CN2023/084455
Other languages
English (en)
French (fr)
Inventor
彭波华
胡念楚
贾斌
Original Assignee
开元通信技术（厦门）有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 开元通信技术（厦门）有限公司 filed Critical 开元通信技术（厦门）有限公司
Publication of WO2024001352A1 publication Critical patent/WO2024001352A1/zh

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/02535—Details of surface acoustic wave devices
    • H03H9/02543—Characteristics of substrate, e.g. cutting angles
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/02535—Details of surface acoustic wave devices
    • H03H9/02637—Details concerning reflective or coupling arrays
    • H03H9/02685—Grating lines having particular arrangements
    • H03H9/02724—Comb like grating lines
    • H03H9/02732—Bilateral comb like grating lines
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/02535—Details of surface acoustic wave devices
    • H03H9/02818—Means for compensation or elimination of undesirable effects
    • H03H9/02834—Means for compensation or elimination of undesirable effects of temperature influence
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves

Definitions

  • the present disclosure relates to the field of filter technology, and in particular to an acoustic wave device structure, a filter and an electronic device with temperature compensation characteristics.
  • Acoustic filters can be used in high-frequency circuits, for example as bandpass filters.
  • An acoustic filter is composed of several acoustic resonators.
  • Acoustic resonators are generally divided into surface acoustic wave (Surface Acoustic Wave, referred to as SAW) devices and bulk acoustic wave (Bulk Acoustic Wave, referred to as BAW) devices according to vibration modes.
  • SAW devices can use inter-digital transducers (IDTs) to convert electrical energy into acoustic energy, or they can also convert acoustic energy into electrical energy.
  • IDT uses a piezoelectric substrate, two opposing busbars at two different potentials, and two sets of electrodes connected to the two busbars.
  • the electric field between two consecutive electrodes at different potentials provides the sound source.
  • the transducer receives an incident wave, charges are generated in the electrodes due to the piezoelectric effect.
  • the energy is confined in the transducer and a high quality factor is obtained. of resonators.
  • SAW devices mainly include conventional SAW (Normal-SAW), bonded substrate SAW (Bonded-Wafer SAW), buried temperature compensation SAW (Buried TC-SAW) and SAW (Piezoelectric On-SAW) with piezoelectric materials on an insulating substrate.
  • Insulator SAW referred to as POI SAW
  • Buried TC-SAW is widely used in mobile communication equipment due to its high performance such as device TCF and Q value, relatively simple manufacturing process, and moderate cost.
  • the Buried TC-SAW structure can use LiNbO 3 or LiTaO 3 as the piezoelectric substrate, grow metal electrodes on the surface, and then lay a thicker temperature compensation layer (such as SiO 2 , or SiO 2 doped with other elements, etc. ) to achieve temperature compensation effect.
  • a thicker temperature compensation layer such as SiO 2 , or SiO 2 doped with other elements, etc.
  • Buried TC-SAW also has problems such as the generation of clutter modes near the main resonance mode, poor film quality yield of the temperature compensation layer, and large thickness errors, which have a great impact on the performance of the device structure itself.
  • a first aspect of the present disclosure provides an acoustic wave device structure with temperature compensation characteristics, which includes a piezoelectric layer, a temperature compensation layer and a resonant electrode layer.
  • the piezoelectric layer serves as a resonant structure of the acoustic wave device structure;
  • the temperature compensation layer is provided corresponding to at least one surface of the piezoelectric layer and is used to provide the piezoelectric layer with Provides a temperature compensation effect;
  • the resonant electrode layer is disposed on the surface of the piezoelectric layer to cooperate with the piezoelectric layer to produce a resonant effect; wherein the resonant electrode layer includes filling bits, and the filling bits expose the surface of the piezoelectric layer for filling Or a planarization material is injected to form a planarization layer that is flush with a surface of the resonant electrode layer.
  • the resonant electrode layer includes a first interdigital electrode and a second interdigital electrode.
  • the first interdigital electrode has a first busbar and a plurality of first interdigital fingers connected to the first busbar;
  • the second interdigital electrode has a second busbar and a plurality of second interdigital fingers connected to the second busbar, wherein the plurality of first interdigital electrodes have a second busbar and a plurality of second interdigital fingers connected to the second busbar.
  • the two interdigitated fingers and the plurality of first interdigitated fingers are parallel and interlaced with each other on the surface of the piezoelectric layer to form an interdigitated effect.
  • the gap formed by the first interdigital electrode and the second interdigital electrode in a parallel and staggered structural relationship is a filling position; or the gap corresponding to the effective resonance area between the resonant electrode layer and the piezoelectric layer
  • the gap between the first interdigital electrode and the second interdigital electrode is a filling position.
  • the resonant electrode layer is a planar thin film electrode layer disposed on the surface of the piezoelectric layer, and the filling position includes at least one filling hole.
  • the at least one filling hole penetrates the planar thin film electrode layer and exposes the surface of the piezoelectric layer.
  • the acoustic wave device structure further includes a first protective layer and/or a second protective layer.
  • the first protective layer corresponds to one surface of the piezoelectric layer and is disposed on one surface of the corresponding temperature compensation layer;
  • the second protective layer corresponds to the other surface of the piezoelectric layer and is disposed on the resonant electrode layer and the planarization layer. on a flat surface.
  • the piezoelectric layer includes an electrode groove, and the electrode groove is recessed on the surface of the piezoelectric layer for disposing the resonant electrode layer.
  • a depth of the electrode groove is less than a thickness of the resonant electrode layer.
  • the depth of the electrode groove is equal to the thickness of the resonant electrode layer, and the surface of the piezoelectric layer where the electrode groove is not provided forms a filling position.
  • a second aspect of the present disclosure provides a filter including a main path, at least one parallel path and at least one resonator.
  • One end of the main path is connected to the input port and the other end is connected to the output port;
  • at least one parallel path is connected to the main path and maintains a parallel relationship with the main path;
  • at least one resonator is connected to one of the at least one parallel paths, wherein at least At least one of the resonators includes the above-described acoustic wave device structure with temperature compensation characteristics.
  • a third aspect of the present disclosure provides an electronic device, which includes the above-mentioned filter.
  • the present disclosure provides an acoustic wave device structure, a filter and an electronic device with temperature compensation characteristics.
  • the acoustic wave device structure can effectively reduce problems such as gaps and gaps in the interface of the temperature compensation layer caused by process defects.
  • the planarization layer can be used to reduce the temperature near the resonance frequency.
  • the parasitic clutter mode is far away from the main resonance peak, improving the overall effective coupling coefficient of the device and reducing the frequency sensitivity of the temperature compensation layer.
  • Figure 1 schematically shows the structural composition cross-section of a Buried TC-SAW device structure with structural defects
  • Figure 2A schematically shows a structural cross-sectional view of the acoustic wave device structure corresponding to the section line A-A' shown in Figure 2G according to an embodiment of the present disclosure
  • Figure 2B schematically shows a comparative simulation diagram of the device impedance curves of the acoustic wave device structure according to an embodiment of the present disclosure, where the planarization materials are SiO 2 and SiN respectively;
  • Figure 2C schematically shows different metal duty ratios (mr) and different temperature compensation layer thicknesses (hSiO 2 ) when the temperature compensation layer material of the Buried TC-SAW device structure with structural defects shown in Figure 1 is SiO 2 Simulation diagram of the corresponding relationship between the effective coupling coefficient K 2 eff of the device structure;
  • 2D schematically illustrates different metal duty ratios (mr) and different temperature compensation layer thicknesses (hSiO) when the temperature compensation layer material of the acoustic wave device structure is SiO2 and the planarization layer material is SiN according to an embodiment of the present disclosure.
  • mr metal duty ratio
  • hSiO temperature compensation layer thicknesses
  • Figure 2E schematically shows different metal duty ratios (mr) and different temperature compensation layer thicknesses (hSiO 2 ) when the temperature compensation layer material of the Buried TC-SAW device structure with structural defects shown in Figure 1 is SiO 2 Simulation diagram of the corresponding relationship between the resonant frequency fs of the device structure;
  • 2F schematically illustrates different metal duty ratios (mr) and different temperature compensation layer thicknesses (hSiO) when the temperature compensation layer material of the acoustic wave device structure is SiO 2 and the planarization layer material is SiN according to an embodiment of the present disclosure.
  • mr metal duty ratios
  • hSiO temperature compensation layer thicknesses
  • FIG. 2G schematically shows a plan view of the piezoelectric layer 201 corresponding to the cross-sectional view of the structure shown in FIG. 2A of an acoustic wave device structure according to an embodiment of the present disclosure
  • FIG. 2H schematically shows a plan view of the piezoelectric layer 201 corresponding to the structural cross-sectional view shown in FIG. 2A of an acoustic wave device structure according to another embodiment of the present disclosure
  • FIG. 3A schematically illustrates a structural group of acoustic wave device structures according to another embodiment of the present disclosure. into a cross-section;
  • FIG. 3B schematically shows a plan view of the piezoelectric layer 301 corresponding to the cross-sectional view of the structure of the acoustic wave device structure shown in FIG. 3A according to another embodiment of the present disclosure
  • Figure 4A schematically shows a cross-sectional view of the structural composition of an acoustic wave device structure according to another embodiment of the present disclosure
  • FIG. 4B schematically shows a cross-sectional view of the structural composition of an acoustic wave device structure according to another embodiment of the present disclosure
  • FIG. 4C schematically shows a cross-sectional view of the structural composition of an acoustic wave device structure according to another embodiment of the present disclosure
  • Figure 5A schematically shows a cross-sectional view of the structural composition of an acoustic wave device structure according to another embodiment of the present disclosure
  • Figure 5B schematically shows a cross-sectional view of the structural composition of an acoustic wave device structure according to another embodiment of the present disclosure.
  • FIG. 6 schematically shows an equivalent connection diagram of a partial structural circuit of a filter according to an embodiment of the present disclosure.
  • modules in the devices in the embodiment can be adaptively changed and arranged in one or more devices different from that in the embodiment.
  • the modules or units or components in the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components.
  • All features disclosed in this specification including accompanying claims, abstract and drawings) and any method so disclosed may be employed in any combination, except that at least some of such features and/or processes or units are mutually exclusive. All processes or units of the equipment are combined.
  • Each feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.
  • several of these means may be embodied by the same item of hardware.
  • the temperature compensation layer generally has a Young's modulus relationship that changes positively with frequency, so that it has the opposite influence on the Young's modulus changes of other structural layers such as piezoelectric and electrodes, so that it can be used to compensate each layer when the temperature changes.
  • the frequency shifts with temperature due to changes in Young's modulus (which causes changes in the sound speed of the material structure).
  • SAW devices such as the Buried TC-SAW device structure often still have corresponding problems that need to be solved after adding a temperature compensation layer.
  • the Buried TC-SAW device can form interdigital electrodes 102 on the piezoelectric layer 101 and form a temperature compensation layer 103 based on the interdigital electrodes 102.
  • the device structure of this structure will have another type of heterogeneity near the main resonance mode.
  • Wave mode specifically using a 128-YX cut angle LiNbO 3 substrate, Rayleigh wave as the main resonance mode
  • SH wave Shear Horizontal
  • the film quality of the temperature compensation layer 103 is prone to problems. For example, defects such as voids and gaps appear in the film layer (such as the interface 104 where the upper end of the interdigital electrode 102 contacts the temperature compensation layer 103).
  • the compensation layer 103 will have a certain thickness error due to its relatively large film thickness.
  • the error control capability is generally proportional to the absolute value of the film thickness. For example, a film with a thickness of 2 ⁇ m is grown. , the consistency of the film is generally ⁇ 5%, that is, an error of about ⁇ 100nm; and this error has a great impact on the resonant frequency and effective coupling coefficient (effective coupling coefficient, k 2 eff ) of the device.
  • the prior art mentions changing the piezoelectric substrate to suppress the clutter mode to a certain extent, but obviously it cannot eliminate the influence of the clutter mode.
  • similar architectures such as ladder filters, because they often Composed of several resonators, it is actually difficult to suppress the clutter modes of all resonators simultaneously using this method; in addition, the existing technology also mentions flattening the temperature compensation layer to achieve a specific thickness position, thereby Remove voids, but this method has extremely limited effect on defects close to positions such as interdigital electrodes; moreover, changes in the thickness of the temperature compensation layer have a greater impact on device performance.
  • the manufacturing process is controlled as much as possible, the growth thickness uniformity is good
  • the process of the film layer is more difficult, and when the resonant frequency is higher, the sensitivity of the performance change to the film thickness becomes more obvious, and the difficulty of the process operation is further increased accordingly.
  • the present disclosure provides an acoustic wave device structure, a filter and an electronic device with temperature compensation characteristics. equipment.
  • the first aspect of the present disclosure provides an acoustic wave device structure with temperature compensation characteristics, which includes a piezoelectric layer, a temperature compensation layer and a resonant electrode layer.
  • the piezoelectric layer serves as a resonant structure for the acoustic wave device structure
  • the temperature compensation layer is arranged corresponding to at least one surface of the piezoelectric layer and is used to provide temperature for the piezoelectric layer. Compensation effect;
  • the resonant electrode layer is disposed on the surface of the piezoelectric layer and is used to cooperate with the piezoelectric layer to produce a resonant effect.
  • the resonant electrode layer includes filling bits, which expose the surface of the piezoelectric layer and are used to fill or inject planarization materials.
  • a planarization layer is formed that is flush with one surface of the resonant electrode layer.
  • the acoustic wave device structure may include a piezoelectric layer 201, a temperature compensation layer 204 and a resonant electrode layer.
  • the piezoelectric layer 201 can serve as the substrate of the acoustic wave device structure, forming a piezoelectric substrate.
  • the piezoelectric layer 201 is generally used to generate the resonance function of the acoustic wave device structure.
  • the preparation material of the piezoelectric layer 201 can be at least one or at least two of aluminum nitride, zinc oxide, lithium niobate or lithium tantalate. mixture to further improve the resonance performance of the piezoelectric layer 201.
  • the piezoelectric layer 201 may be a multi-layer piezoelectric structure stack layer composed of one or more different piezoelectric materials.
  • the temperature compensation layer 204 can be disposed above the upper surface of the piezoelectric layer 201 with a resonant electrode layer sandwiched between them for direct contact with the resonant electrode layer to compensate for the resonant frequency of the piezoelectric layer 201 changes with temperature.
  • the temperature compensation layer 204 may be made of a dielectric material, specifically silicon dioxide (SiO 2 ), phosphosilicate glass, or other materials with a positive frequency temperature coefficient.
  • the temperature compensation layer 204 can also be disposed on the lower surface of the piezoelectric layer 201, that is, not in direct contact with the resonant electrode layer.
  • the simulation basis is that the piezoelectric material of the piezoelectric layer 201 is 128-YX LiNbO 3 , and the resonant electrode layer is selected as an interdigital electrode layer of metallic copper Cu, and the temperature compensation layer is selected as SiO with a thickness of 0.3 ⁇ .
  • 2 Materials Generally, there is a certain correspondence between the thickness of silicon dioxide and the period of the interdigital electrode. ⁇ is the period in the direction of the interdigital electrode arrangement. For example, for a band8 (930MHz) filter, the period ⁇ in the direction of the interdigital electrode arrangement is about is 3.8um, please refer to Figure 2G for details).
  • the structural form of the acoustic wave device structure can actually refer to the structure shown in Figure 1
  • the composition of the defective Buried TC-SAW device structure is that the temperature compensation layer preparation material is SiO 2 and it fully covers the exposed surface of the resonant electrode layer; at this time, corresponding to the solid curve shown in Figure 2B, the SiO 2 material
  • the temperature compensation layer 103 has the impedance characteristics of a typical resonator, and the frequencies corresponding to its minimum and maximum values are the resonant frequency fs and the anti-resonant frequency fp respectively; when the temperature changes, due to the Young's modulus of the piezoelectric, electrode layer and other materials, fs and fp will shift due to changes (changes in Young's modulus will cause changes in the material's sound velocity) and the thermal expansion characteristics of each layer.
  • the temperature compensation layer generally has a Young's modulus relationship that changes positively with frequency, which is just opposite to electrodes such as the piezoelectric layer 101 and the interdigital electrode 102, so it can compensate for changes in frequency with temperature.
  • the acoustic wave device structure of the temperature compensation layer 103 of SiO 2 material shown in FIG. 1 has significant technical shortcomings that are difficult to overcome.
  • the resonant electrode layer covers the surface of the piezoelectric layer 201 and is in direct contact with the surface of the piezoelectric layer 201 .
  • the preparation material of the resonant electrode layer can be a metal or metal alloy material with good conductive properties. Specifically, it can be aluminum, molybdenum, copper, gold, etc. that are compatible with the semiconductor process. At least one metal material or at least two metal alloy materials among platinum, silver, nickel, chromium, tungsten, etc., and the resonant electrode layer can also be a multi-layer structure electrode of at least one of the above metal materials.
  • the filling position on the resonant electrode layer may be an open structure, specifically, it may be an opposite gap, opening or opening on the resonant electrode layer, for relative to the resonant electrode layer.
  • the resonant electrode layer exposes the surface of the piezoelectric layer 201 to prevent the resonant electrode layer from completely covering the piezoelectric layer 201 . Therefore, a planarization material can be filled or injected through the filling position to form a planarization layer 203 relative to the resonant electrode layer and the piezoelectric layer 201.
  • the planarization layer 203 is level with the upper surface of the resonant electrode layer, that is, two
  • the surface on the other side that is not in contact with the piezoelectric layer 201 is highly flat, thus having a flattening effect.
  • the planarization material of the planarization layer 203 is a dielectric material, and the thickness can be the same as or similar to the thickness of the resonant electrode layer, but the planarization layer 203 and the resonant electrode layer need to be flush with the back surface of the piezoelectric layer 201 to form Flatten the interface.
  • the planarization material of the planarization layer 203 in the embodiment of the present disclosure is specifically a high-sound-velocity dielectric material different from the temperature compensation layer 204, and specifically can be silicon nitride (ie, SiN), nitrogen Aluminum etc.
  • the simulation basis is that the piezoelectric material of the piezoelectric layer 201 is 128-YX LiNbO 3 , and the resonant electrode layer is selected as an interdigital electrode layer of metallic copper Cu, and the temperature compensation layer is selected as SiO with a thickness of 0.3 ⁇ . 2 materials. Therefore, when the preparation material of the temperature compensation layer 204 as shown in FIG. 2A is SiO 2 and the planarization material is SiN, in fact, the structural form of the acoustic wave device structure can refer to the acoustic wave device of the embodiment of the present disclosure shown in FIG.
  • the composition of the device structure means that the temperature compensation layer 204 can only cover the upper end surface of the resonance layer, and its side surface is covered by the planarization layer 203 .
  • the minimum value of the equivalent impedance corresponding to the temperature compensation resonant frequency position is due to the flattening material SiN of the flattening layer 203 (the flattening layer 203 of SiN material can improve the The overall sound speed of the part, and the corresponding resonant frequency is also higher) is higher than that of the SiO 2 material.
  • the resonant frequency of the SiN planarization layer 203 structure represented by the dotted curve is higher and is higher than the anti-resonant frequency fp.
  • the clutter mode can be moved to a higher frequency with the help of the above-mentioned planarization layer 203 structure based on SiN material, which helps to weaken the The effect of waves on the filter passband and roll-off. Therefore, adding the planarization layer 203 based on SiN material can reduce the passband or roll-off ripple caused by the clutter mode.
  • the values of these two parameters may be within the variation range in the figure, but overall, as shown in FIG. 2D , the planarization layer 203 used in the embodiment of the present disclosure is And when SiN material is used, the effective coupling coefficient k 2 eff of the acoustic wave device structure is higher. Obviously, the structural design of the planarization layer 203 can help design a filter with a larger bandwidth.
  • the simulation diagram of the relationship between the resonator rate fs of the device and the thickness of the temperature compensation layer h SiO 2 changes.
  • the acoustic wave device structure shown in Figure 2E corresponds to In the traditional device structure shown in Figure 1, the material of the planarization layer and the temperature compensation layer are consistent and both are SiO2 .
  • the acoustic wave device structure shown in Figure 2F corresponds to the device structure of the embodiment of the present disclosure shown in Figure 2A, and is flat
  • the material of the temperature compensation layer 204 may be SiN, and the temperature compensation layer 204 may be made of SiO 2 .
  • the resonant frequency fs will basically show a trend of first increasing and then decreasing with the thickness of the temperature compensation layer h SiO 2 ; however, if the temperature of a thinner thickness h SiO 2 is used, Compensation layer, the temperature compensation effect is poor, and the device structure will be more sensitive to changes in temperature. Therefore, for filters with strict requirements on insertion loss, roll-off, suppression, etc., Generally, a thicker temperature compensation layer needs to be used to reduce the influence of the temperature of the piezoelectric layer 201 on the frequency.
  • the thickness of the temperature compensation layer hSiO 2 ( ⁇ ) relative to the abscissa is generally 0.3-0.4.
  • the curve segment of the left curve group located in this interval is obviously smoother than the right curve, that is, the resonant frequency fs changes more smoothly with the thickness h SO 2 of the temperature compensation layer 204 (specifically Refer to the corresponding curve slope), that is, the planarization layer 203 of SiN material can effectively reduce the frequency change sensitivity.
  • the traditional structure of growing a temperature compensation layer directly on the metal layer is as shown in Figure 1 .
  • the film quality of the thicker temperature compensation layer grown directly on the metal surface is prone to problems. For example, holes and gaps are prone to appear in the film layer, especially at the position 104 immediately adjacent to the temperature compensation layer and the electrode metal. These defects will directly lead to a decrease in the Q value of the device and also affect the performance of the filter device.
  • the corresponding unit of the resonant electrode layer and the planarization layer 203 is also required.
  • the sides are planarized at the same time, so that defects such as holes and gaps that appear in the immediate vicinity of the two are removed through the planarization process. Therefore, the structural design of the above-mentioned planarization layer 203 and the resonant electrode layer with a single-sided surface flattening effect in the embodiment of the present disclosure can avoid the influence of traditional defects such as holes and gaps.
  • the temperature compensation layer 204 when the temperature compensation layer 204 is in contact with the single-sided surface of the planarization layer 203 and the resonant electrode layer, the temperature compensation layer 204 also has high requirements on the flatness of the single-sided surface in order to achieve good flatness. Surface contact can improve the Q value of the device and improve the filtering performance of the device. In other words, the structural design of the above-mentioned planarization layer 203 and the resonant electrode layer can significantly improve the device Q value and ensure device performance.
  • the material used to prepare the planarization layer 203 is generally a material whose Young's modulus changes negatively with temperature, such as SiN, so it generally has no temperature compensation effect at all; and since the device vibration area is on the surface of the piezoelectric layer , the temperature compensation layer should preferably be in direct contact with the surface of the piezoelectric layer or in direct contact with the surface of the piezoelectric layer. Only when the vibrating electrode layer is in direct contact can the temperature compensation effect be better achieved.
  • the acoustic wave device structure can effectively reduce problems such as gaps and gaps in the temperature compensation layer interface caused by process defects.
  • the planarization layer 203 can be used to The parasitic clutter modes near the resonant frequency are far away from the main resonance peak, which improves the overall effective coupling coefficient of the device and reduces the sensitivity of the temperature compensation layer to the frequency.
  • the resonant electrode layer includes first interdigital electrodes 221 and second interdigital electrodes 222 .
  • the first interdigital electrode 221 has a first busbar and a plurality of first interdigitals connected to the first busbar;
  • the second interdigital electrode 222 has a second busbar and a plurality of second interdigitals connected to the second busbar,
  • the plurality of second interdigitated fingers and the plurality of first interdigitated fingers are parallel and interlaced with each other on the surface of the piezoelectric layer to form an interdigitated effect.
  • an interdigital interdigitation effect is formed between the first interdigital electrode 221 and the second interdigital electrode 222 .
  • the first interdigital electrode 221 can be used as an input electrode for the resonance effect
  • the second interdigital electrode 222 can be used as an input electrode for the resonance effect. It also means that the electrode 222 can be used as a corresponding output electrode, so that the resonant electrode layer exhibits a surface acoustic wave resonance form on the surface of the piezoelectric layer 201.
  • the resonance mode of the SAW device refer to the resonance mode of the SAW device.
  • the first interdigital electrode 221 and the second interdigital electrode 222 can form the first interdigital electrode 221 and the second interdigital electrode 222 by means of their respective busbars and the staggered distribution of a plurality of fingers on the surface of the piezoelectric layer 201 .
  • the two fingers refer to the gap between the two electrodes 222 . These gaps can be used as the above-mentioned filling positions.
  • the above-mentioned acoustic wave device structure of the embodiment of the present disclosure can be applied to devices based on surface acoustic waves, providing higher and more stable device performance.
  • the gap formed by the first interdigital electrode and the second interdigital electrode in a parallel and staggered structural relationship is a filling position; or the resonant electrode layer and The gap between the first interdigital electrode and the second interdigital electrode corresponding to the effective resonance area between the piezoelectric layers is a filling position.
  • the surface area of the piezoelectric layer 201 between the first bus bar of the first interdigital electrode 221 and the second bus bar of the second interdigital electrode 222 is composed of a plurality of first interdigital fingers and a plurality of third interdigital electrodes. All the gaps on the surface of the exposed piezoelectric layer 201 formed by the interlacing of the two fingers can be used as filling positions to realize the filling of the planarization material, and form a gap between the gaps and in contact with the side surface of the adjacent fingers.
  • the contact planarization layer 203 At this time, all gaps corresponding to the staggered overlapping areas and non-overlapping areas of the interdigital electrodes between the first bus bar and the second bus bar are regarded as areas where the planarization layer 203 is located.
  • the planarization layer 203 ′ may only cover the overlapping area of the interdigitals of the first interdigital electrode 221 and the second interdigital electrode 222 , that is, the two interdigitated electrodes 221 and 222 interdigitated electrodes 221 and 222 interdigitated electrodes.
  • the gaps between the fingers of the effective area between the piezoelectric layers 201 serve as filling positions.
  • the resonance effect of the piezoelectric layer 201 mainly works in this effective area, it is only necessary to ensure the film quality and flatness of the temperature compensation layer 204 in this area, and the high sound velocity material filled in the filling position ( Since the surface of the planarization layer 203' made of SiN (SiN) has good smoothness in contact with the temperature compensation layer 204, it will help to increase the overall sound speed in the resonance effective area and form a sound speed difference with the end of the cross-valued electrode. , while effectively limiting the sound wave within the effective area, suppressing the lateral parasitic mode, thereby improving the Q value of the device.
  • the above-mentioned overlapping area of the interdigitates of the first interdigital electrode 221 and the second interdigital electrode 222 does not actually include the interdigitated areas of the first interdigital electrode 221 and the second interdigital electrode 222 .
  • the resonant electrode layer 302 is a planar thin film electrode layer disposed on the surface of the piezoelectric layer 301 .
  • the filling position includes at least one filling hole, and the at least one filling hole passes through the plane.
  • the thin film electrode layer exposes the surface of the piezoelectric layer 301.
  • the resonant electrode layer 302 disposed on one surface of the piezoelectric layer 301 can cooperate with another lower electrode layer disposed on the other surface of the piezoelectric layer 301 so that the resonant electrode layer 302 It exhibits a bulk acoustic wave resonance form with the piezoelectric layer 301.
  • the filling positions may have multiple filling holes, and may be distributed on the resonant electrode layer 302 in an array arrangement. Each filling hole is a through hole passing through the resonant electrode layer 302, enabling piezoelectricity.
  • the surface of layer 301 is exposed for filling corresponding planarization materials, such as SiN, to form a planarization layer 303 based on these filled holes.
  • the above-mentioned acoustic wave device structure of the embodiment of the present disclosure can be applied to devices based on body surface waves, providing higher and more stable device performance.
  • the acoustic wave device structure further includes a first protective layer and/or a second protective layer.
  • the first protective layer corresponds to a surface of the piezoelectric layer and is disposed on a surface of the corresponding temperature compensation layer. on the surface;
  • the second protective layer corresponds to the other surface of the piezoelectric layer and is disposed on the flat surface formed by the resonant electrode layer and the planarization layer.
  • the acoustic wave device structure of the embodiment of the present disclosure may specifically include a piezoelectric layer 401, a resonant electrode layer 402, a planarization layer 403 and a temperature compensation layer 404.
  • the resonant electrode layer 402 may be as shown in Figure 2A, Figure 2G and Figure 2H interdigital electrode layer. Wherein, the one-sided surface of the resonant electrode layer 402 and the planarization layer 403 has a flat planarization effect.
  • the acoustic wave device structure may also have a corresponding protective layer disposed in the acoustic wave device structure.
  • the protective layer generally covers the surface of the temperature compensation layer 4, the single side surface of the resonant electrode layer 402 and the planarization layer 403 that has a planarization effect, or both of the above two surfaces, thereby providing the temperature compensation layer with a flattening effect.
  • the acoustic wave device structure forms a resonant electrode layer 402 and a planarization layer 403 with a single-sided planarized surface on the surface of the piezoelectric layer 401, and on the resonant electrode layer 402 and the planarization layer 403, A temperature compensation layer 404 is formed on the single-sided planarized surface, and a protective layer 405 is formed on the surface of the temperature compensation layer 404; as shown in FIG. 4B, the acoustic wave device structure is formed with single-sided planarization on the surface of the piezoelectric layer 401.
  • a temperature compensation layer 441 is formed, and a protective layer 452 is further formed on the lower surface of the temperature compensation layer 441; as shown in FIG. 4C, the acoustic wave device structure forms a resonant electrode layer with a single-sided planarized surface on the surface of the piezoelectric layer 401.
  • thermoelectric layer 402 and planarization layer 403 and form a temperature compensation layer 442 on the single-sided planarized surface of the resonant electrode layer 402 and the planarization layer 403, and further form a protective layer 453 on the upper surface of the temperature compensation layer 442, and,
  • a temperature compensation layer 443 is formed on the other surface of the piezoelectric layer 401, and a protective layer 454 is further formed on the lower surface of the temperature compensation layer 443...
  • the protective layer design of other embodiments can also be used, There are no specific restrictions.
  • the service life of the device can be significantly improved, ensuring the above-mentioned "effective reduction of gaps, gaps and other problems at the temperature compensation layer interface caused by process defects, and at the same time, the planarization layer 203 can be used to reduce the temperature near the resonance frequency.
  • the parasitic clutter mode is far away from the main resonance peak, which improves the overall effective coupling coefficient of the device and reduces the sensitivity of the temperature compensation layer to the frequency.”
  • Technical effect improve device structural stability.
  • the acoustic wave device structure can also have an edge reflection layer located above the resonant electrode layer for suppressing the lateral mode, a metal connection layer connecting the interdigital electrodes and leading to the external structure, etc.
  • the details can be based on the actual needs of the device structure. The adjustment design will not be described in detail here.
  • the acoustic wave device structure can also have a substrate structure in order to enhance the structural stability and improve device performance.
  • the preparation material of the substrate structure can be silicon, quartz, alumina, etc. One type, or a stack structure of multiple materials.
  • the preparation materials of the various electrode layers mentioned in the embodiments of the present disclosure may also be consistent with the preparation materials of the resonant electrode layer mentioned above, and will not be described again here.
  • the piezoelectric layer 501 includes electrode grooves, which are recessed on the surface of the piezoelectric layer 501 for disposing the resonant electrode layer 502 .
  • the acoustic wave device structure of the embodiment of the present disclosure may specifically include a piezoelectric layer 501, a resonant electrode layer 502 and a temperature compensation layer 504.
  • the resonant electrode layer 502 may be an interdigital electrode layer as shown in Figure 2A, Figure 2G and Figure 2H .
  • the electrode groove is recessed on the surface of the piezoelectric layer 501, when the resonant electrode layer 502 is formed in the electrode groove, it will be embedded in the piezoelectric layer 501 to form an embedded electrode to realize the connection with the piezoelectric layer 501.
  • the electrical layer 501 has a more stable structural bonding effect.
  • the size of the acoustic wave device structure can be compressed in the vertical direction.
  • the above-mentioned embedded electrode structure when the above-mentioned embedded electrode structure is embedded in the piezoelectric layer 501, it can realize piezoelectric contact in multiple directions compared to the case of unidirectional contact on the surface of the piezoelectric layer, because the inverse piezoelectric effect is Through the signal in the electrode, the piezoelectric layer is excited to vibrate at the input electrode, and the sound wave is transmitted to the output electrode, and relies on the piezoelectric effect to generate an output signal at the output electrode, realizing the energy conversion of electricity-acoustic-electricity. Therefore, the resonant electrode layer The larger contact area between 502 and the piezoelectric layer 501 can further stimulate the piezoelectric characteristics and increase the effective coupling coefficient, thereby further improving device performance.
  • the depth of the electrode groove is less than the thickness of the resonant electrode layer 502 .
  • a planarization layer 503 may be further included.
  • the depth of the electrode groove is less than the thickness of the resonant electrode layer 502 , it means that the resonant electrode layer 502 is partially embedded in the surface of the piezoelectric layer 501 , and the other part protrudes from the surface of the piezoelectric layer 501 .
  • the surface of the piezoelectric layer 501 can be divided by the portion of the resonant electrode layer 502 protruding outside the surface of the piezoelectric layer 501, forming a resonance structure corresponding to the resonance electrode layer 502.
  • the gaps in the electrode layer 502 serve as filling positions for the planarization layer 503 .
  • the filling position is filled with planarization material, and after the filling of the planarization material is completed, the combination of the planarization layer and the resonant electrode layer is planarized to finally form the planarization layer 503 and the resonant electrode layer 502 .
  • the contact area between the piezoelectric layer 501 and the resonant electrode layer 502 can be larger, the effective coupling coefficient of the device can be better improved, and the overall performance of the device can be improved accordingly.
  • the size of the acoustic wave device structure can be compressed in the vertical direction.
  • the depth of the electrode groove is equal to the thickness of the resonant electrode layer 502 , and the surface of the piezoelectric layer 501 where the electrode groove is not provided forms a filling position.
  • a planarization layer 503' may be further included.
  • the depth of the electrode groove is equal to the thickness of the resonant electrode layer 502 , it means that the resonant electrode layer 502 has been completely embedded in the surface of the piezoelectric layer 501 .
  • the pattern of the piezoelectric layer 501 with respect to the resonant electrode layer 502 can be formed relatively.
  • the exposed piezoelectric surface area of the piezoelectric layer 501 of the resonant electrode layer 502 arranged oppositely in this pattern can be used to constitute the filling position of the planarization layer 503'.
  • a planarization material is injected or implanted into the filling position, so that the corresponding planarization material can enter the exposed surface of the piezoelectric layer 501 in the form of high-concentration doping, and form a doped layer with a set thickness, as the planarization layer 503'.
  • the planarization process can be directly performed after the resonant electrode layer 502 is grown, and then the planarization material can be used.
  • the injection or implantation operation on the surface of the exposed piezoelectric layer 501 eliminates the need to perform a planarization process on the planarization layer 503', and can also form the planarization layer 503' and the planarization of the single-side surface of the resonant electrode layer 502. .
  • the contact area between the piezoelectric layer 501 and the resonant electrode layer 502 can be further increased, the effective coupling coefficient of the device can be better improved, the overall performance of the device can be improved accordingly, and the size of the device structure can be further compressed in the vertical direction. .
  • the contact effect between the temperature compensation layer and the resonant electrode layer or the piezoelectric layer can be ensured, the corresponding temperature compensation effect can be achieved.
  • the electrode groove can achieve size compression of the acoustic wave device structure in the vertical direction, which is conducive to the miniaturization, integration and precision of the acoustic wave device structure.
  • the structural design can significantly improve the structural stability between the piezoelectric layer 501 and the resonant electrode layer 502, and obtain better device performance by increasing the piezoelectric contact area.
  • the layer affects the frequency sensitivity and reduces problems such as gaps and gaps in the temperature compensation layer caused by process defects. It can also enhance structural stability, compress the vertical size of the device structure, and reduce the preparation cost of structural devices. The details will not be described here. .
  • a second aspect of the present disclosure provides a method for manufacturing the above-mentioned acoustic wave device structure with temperature compensation characteristics.
  • the resonant electrode layer structure is generally grown and patterned first, and then a planarization layer is grown on the surface of the piezoelectric layer and the resonant electrode layer, and is flattened.
  • Chemical treatment such as chemical mechanical polishing (CMP) is used to smooth the single-sided surfaces of both devices until the resonant electrode layer reaches the preset thickness, and finally a temperature compensation layer is grown onto the final device structure.
  • CMP chemical mechanical polishing
  • the growth order of the resonant electrode layer (such as the interdigital electrode) and the planarization layer can also be exchanged. Just ensure that the final two layers have a smooth surface with one side flat to avoid affecting the film formation quality of the subsequent temperature compensation layer growth. That’s it.
  • the chemical mechanical polishing (CMP) process can be used to flatten the surfaces of one side of the two layers, which can generally ensure that at least one side of the two layers is in a flat state with each other.
  • forming a smooth surface on one side of the resonant electrode layer and the planarization layer will also help to subsequently grow a high-quality temperature compensation layer, control the surface flatness of the temperature compensation layer, reduce device defects, thereby significantly improving the Q value, and through
  • the planarization process of the planarization layer prevents it from blocking the contact between the temperature compensation layer and the end surface of the electrode layer.
  • the surface flatness of the temperature compensation layer can also be improved during the preparation process. It is easier to control, thus significantly reducing preparation costs.
  • the specific process steps can be adjusted accordingly according to the actual acoustic wave device structure, and will not be described in detail.
  • the third aspect of the present disclosure provides a filter, which includes a main path path, at least one parallel path and at least one resonator.
  • One end of the main path is connected to the input port Tx, and the other end is connected to the output port Ant;
  • At least one parallel path is connected to the main path and maintains a parallel relationship with the main path;
  • At least one resonator is connected to one of the at least one parallel paths, wherein at least one of the at least one resonator includes the above-mentioned acoustic wave device structure with temperature compensation characteristics.
  • the filter is a ladder filter composed of multiple acoustic wave resonator units. Specifically, it is built up of several series branch resonator modules 601 and parallel branch resonator modules 602. Specifically, the series The branch resonator module 601 has a plurality of acoustic wave resonators 611, 612 and 613 connected in series on the main path, and the parallel branch resonator module 602 has a plurality of acoustic wave resonators 621, 621, 621, 612 and 613 connected in parallel paths respectively. 622 and 623 to form the corresponding ladder filter structure.
  • the anti-resonant frequency fp point of its parallel resonator generally falls within the passband
  • the resonant frequency fs point of the series resonator generally lies within the passband, that is, the parallel branch resonator module
  • the antiresonant frequencies of the respective parallel resonators of 602 and the resonant frequencies of the respective series resonators of the series branch resonator module 601 will appear within the passband of the filter. Therefore, as a preferred implementation example of the filter, at least one or more parallel resonators in the parallel branch resonator module 602 can be implemented with the acoustic wave device structure with temperature compensation characteristics described in FIGS.
  • the acoustic wave device structure with temperature compensation characteristics of one or more of the above-mentioned embodiments of the present disclosure may also be used for the series resonators in the series branch resonator module 601 .
  • the above-mentioned planarization layer structure based on SiN materials can be used to move the clutter mode to a higher frequency, which helps to weaken the wave. Effect on filter passband and roll-off. Therefore, adding a planarization layer based on SiN materials can effectively reduce the passband or roll-off ripple caused by clutter modes.
  • a fourth aspect of the present disclosure provides an electronic device, which includes the above-mentioned filter.
  • the electronic device can be a mobile or fixed computer device such as a mobile phone, a notebook, a tablet, a POS machine, a vehicle-mounted computer, or other devices with intelligent information processing functions that can use high-frequency and high-bandwidth 4G, 5G, etc. Communication electronic equipment.

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

本公开提供了一种具有温度补偿特性的声波器件结构、滤波器和电子设备。其中，该声波器件结构包括压电层、温度补偿层以及谐振电极层。温度补偿层对应于所述压电层的至少一表面设置，用于为所述压电层提供温度补偿效果；其中，所述谐振电极层包括填充位，填充位暴露所述压电层的表面，用于填充或注入平坦化材料形成与所述谐振电极层的一表面持平的平坦化层。通过上述与谐振电极层的表面持平的平坦化层，使得该声波器件结构能够有效减少因工艺缺陷导致的温度补偿层界面的缺陷问题，同时可以通过该平坦化层将谐振频率附近的寄生杂波模式远离主谐振峰，提高该器件的整体有效耦合系数，降低温度补偿层影响频率的灵敏度。

Description

具有温度补偿特性的声波器件结构、滤波器和电子设备 技术领域
本公开涉及滤波器技术领域，尤其涉及一种具有温度补偿特性的声波器件结构、滤波器和电子设备。
背景技术
声波滤波器可在高频电路中使用，例如可以用作带通滤波器。声波滤波器由若干个声波谐振器组合而成。声波谐振器按振动模式一般分为声表面波(Surface Acoustic Wave，简称SAW)器件和体声波(Bulk Acoustic Wave，简称BAW)器件。SAW器件可以采用叉指电极(Inter-Digital Transducer，简称IDT)来将电能转换成声能，或者也可以将声能转换成电能。IDT使用压电基板和处于两个不同电位的两个相对母线(Busbar)以及与两个母线连接的两组电极。由于逆压电效应，处于不同电位的两个连续电极之间的电场提供了声源。相反地，如果换能器接收入射波，则由于压电效应而在电极中产生电荷，通过将换能器置于两个反射栅之间，将能量限制在换能器中，获得高品质因数的谐振器。
SAW器件主要包括常规SAW(Normal-SAW)、键合衬底SAW(Bonded-Wafer SAW)、掩埋型温度补偿SAW(Buried TC-SAW)以及在绝缘衬底上设置压电材料的SAW(Piezoelectric On Insulator SAW，简称POI SAW)等类型。其中，Buried TC-SAW因器件TCF、Q值等性能较高，且制作工艺相对简单、成本适中，被广泛应用于移动通信设备中。一般，Buried TC-SAW结构可以使用LiNbO3或LiTaO3作为压电衬底，在表面生长金属电极，然后铺一层较厚的温度补偿层(如SiO2，或掺杂其它元素的SiO2等)，达到温度补偿效果。但是Buried TC-SAW也存在诸如在主谐振模式附近产生杂波模式、温度补偿层的膜质量良率较差以及厚度误差较大等对器件结构本身产生较大性能影响的问题。
发明内容
本公开的第一方面提供了一种具有温度补偿特性的声波器件结构，其中，包括压电层、温度补偿层以及谐振电极层。压电层作为声波器件结构的谐振结构；温度补偿层对应于压电层的至少一表面设置，用于为压电层 提供温度补偿效果；谐振电极层设置于压电层的表面上，用于与压电层相配合产生谐振效应；其中，谐振电极层包括填充位，填充位暴露压电层的表面，用于填充或注入平坦化材料形成与谐振电极层的一表面持平的平坦化层。
根据本公开的实施例，谐振电极层包括第一叉指电极和第二叉指电极。第一叉指电极具有第一母线和连接该第一母线的多个第一叉指；第二叉指电极具有第二母线和连接该第二母线的多个第二叉指，其中多个第二叉指与多个第一叉指在压电层的表面上相互平行交错形成叉指效果。
根据本公开的实施例，第一叉指电极和第二叉指电极在平行交错的结构关系中所形成的间隙为填充位；或者谐振电极层与压电层之间的有效谐振区域所对应的第一叉指电极和第二叉指电极之间的间隙为填充位。
根据本公开的实施例，谐振电极层为设置于压电层表面上的平面薄膜电极层，填充位包括至少一个填充孔，至少一个填充孔穿设平面薄膜电极层，暴露压电层的表面。
根据本公开的实施例，声波器件结构还包括第一保护层和/或第二保护层。第一保护层对应于压电层的一表面，设置于相应的温度补偿层的一表面上；第二保护层对应于压电层的另一表面，设置于谐振电极层和平坦化层所形成的持平表面上。
根据本公开的实施例，压电层包括电极槽，电极槽凹设于压电层的表面，用于设置谐振电极层。
根据本公开的实施例，其中，电极槽的深度小于谐振电极层的厚度。
根据本公开的实施例，电极槽的深度等于谐振电极层的厚度，未设置电极槽的压电层的表面形成填充位。
本公开的第二方面提供了一种滤波器，其中，包括主路径、至少一个并联路径和至少一个谐振器。主路径一端连接输入端口，另一端连接输出端口；至少一个并联路径连接在主路径上，与主路径保持并联关系；至少一个谐振器连接于至少一个并联路径中的一个并联路径上，其中，至少一个谐振器中的至少一个谐振器包括上述的具有温度补偿特性的声波器件结构。
本公开的第三方面提供了一种电子设备，其中，包括上述的滤波器。
本公开提供了一种具有温度补偿特性的声波器件结构、滤波器和电子设备。通过上述与谐振电极层的表面持平的平坦化层，使得该声波器件结构能够有效减少因工艺缺陷导致的温度补偿层界面的空隙、缝隙等问题，同时可以通过该平坦化层将谐振频率附近的寄生杂波模式远离主谐振峰，提高该器件的整体有效耦合系数，降低温度补偿层影响频率的灵敏度。
附图说明
图1示意性示出了一种具有结构缺陷的Buried TC-SAW器件结构的结构组成剖面图；
图2A示意性示出了根据本公开一实施例的声波器件结构的对应图2G所示剖线A-A′的结构组成剖面图；
图2B示意性示出了根据本公开一实施例的声波器件结构的平坦化材料分别为SiO2和SiN的器件阻抗曲线对比仿真图；
图2C示意性示出了对应图1所示具有结构缺陷的Buried TC-SAW器件结构的温度补偿层材料为SiO2时，不同金属占空比(mr)和不同温度补偿层厚度(hSiO2)对器件结构的有效耦合系数K2 eff的对应关系的仿真图；
图2D示意性示出了根据本公开一实施例的声波器件结构的温度补偿层材料为SiO2且平坦化层材料为SiN时，不同金属占空比(mr)和不同温度补偿层厚度(hSiO2)对器件结构的有效耦合系数k2 eff的对应关系的仿真图；
图2E示意性示出了对应图1所示具有结构缺陷的Buried TC-SAW器件结构的温度补偿层材料为SiO2时，不同金属占空比(mr)和不同温度补偿层厚度(hSiO2)对器件结构的谐振频率fs的对应关系的仿真图；
图2F示意性示出了根据本公开一实施例的声波器件结构的温度补偿层材料为SiO2且平坦化层材料为SiN时，不同金属占空比(mr)和不同温度补偿层厚度(hSiO2)对器件结构的谐振频率fs的对应关系的仿真图；
图2G示意性示出了根据本公开一实施例的声波器件结构的对应图2A所示结构剖面图的压电层201的平面组成俯视图；
图2H示意性示出了根据本公开另一实施例的声波器件结构的对应图2A所示结构剖面图的压电层201的平面组成俯视图；
图3A示意性示出了根据本公开另一实施例的声波器件结构的结构组 成剖面图；
图3B示意性示出了根据本公开另一实施例的声波器件结构的对应图3A所示结构剖面图的压电层301的平面组成俯视图；
图4A示意性示出了根据本公开另一实施例的声波器件结构的结构组成剖面图；
图4B示意性示出了根据本公开另一实施例的声波器件结构的结构组成剖面图；
图4C示意性示出了根据本公开另一实施例的声波器件结构的结构组成剖面图；
图5A示意性示出了根据本公开另一实施例的声波器件结构的结构组成剖面图；
图5B示意性示出了根据本公开另一实施例的声波器件结构的结构组成剖面图；以及
图6示意性示出了根据本公开一实施例的滤波器的部分结构组成电路等效连接图。
具体实施方式
为使本发明的目的、技术方案和优点更加清楚明白，以下结合具体实施例，并参照附图，对本发明进一步详细说明。
需要说明的是，在附图或说明书正文中，未绘示或描述的实现方式，均为所属技术领域中普通技术人员所知的形式，并未进行详细说明。此外，上述对各元件和方法的定义并不仅限于实施例中提到的各种具体结构、形状或方式，本领域普通技术人员可对其进行简单地更改或替换。
还需要说明的是，实施例中提到的方向用语，例如“上”、“下”、“前”、“后”、“左”、“右”等，仅是参考附图的方向，并非用来限制本公开的保护范围。贯穿附图，相同的元素由相同或相近的附图标记来表示。在可能导致对本公开的理解造成混淆时，将省略常规结构或构造。
并且图中各部件的形状和尺寸不反映真实大小和比例，而仅示意本公开实施例的内容。另外，在权利要求中，不应将位于括号之间的任何参考符号构造成对权利要求的限制。
再者，单词“包含”不排除存在未列在权利要求中的元件或步骤。位 于元件之前的单词“一”或“一个”不排除存在多个这样的元件。
说明书与权利要求中所使用的序数例如“第一”、“第二”、“第三”等的用词，以修饰相应的元件，其本身并不意味着该元件有任何的序数，也不代表某一元件与另一元件的顺序或是制造方法上的顺序，这些序数的使用仅用来使具有某命名的一元件得以和另一具有相同命名的元件能做出清楚区分。
本领域那些技术人员可以理解，可以对实施例中的设备中的模块进行自适应性地改变并且把他们设置在与该实施例不同的一个或多个设备中。可以把实施例中的模块或单元或组件组合成一个模块或单元或组件，以及此外可以把他们分成多个子模块或子单元或子组件。除了这样的特征和/或过程或者单元中的至少一些是相互排斥之外，可以采用任何组合对本说明书(包括伴随的权利要求、摘要和附图)中公开的所有特征以及如此公开的任何方法或者设备的所有过程或单元进行组合。除非另外明确陈述，本说明书(包括伴随的权利要求、摘要和附图)中公开的每个特征可以由提供相同、等同或相似目的的代替特征来代替。并且，在列举了若干装置的单元权利要求中，这些装置中的若干个可以是通过同一个硬件项来具体体现。
类似地，应当理解，为了精简本公开并帮助理解各个公开方面的一个或多个，在上面对本公开的示例性实施例的描述中，本公开的各个特征有时被一起分组到单个实施例、图、或者对其的描述中。然而，并不应将该公开的方法解释成反映如下意图：即所要求保护的本公开要求比在每个权利要求中所明确记载的特征更多的特征。更确切地说，如下面的权利要求书所反映的那样，公开方面在于少于前面公开的单个实施例的所有特征。因此，遵循具体实施方式的权利要求书由此明确地并入该具体实施方式，其中每个权利要求本身都作为本公开的单独实施例。
温度补偿层一般具有随频率正向变化的杨氏模量关系，使得其与其他结构层的压电和电极等杨氏模量变化影响刚好相反，从而能够在温度变化时，用于补偿各层因杨氏模量变化(会导致材料结构声速变化)导致的频率随温度的偏移变化。但是诸如Buried TC-SAW器件结构在内的SAW器件往往在加入温度补偿层之后仍然存在相应的问题亟待解决。如图1所示， Buried TC-SAW器件可以在压电层101上形成叉指电极102，并基于该叉指电极102形成温度补偿层103，但这种结构形式的器件结构会在主谐振模式附近存在另一种杂波模式，具体地如使用128-YX切角的LiNbO3衬底，Rayleigh波作为主谐振模式，在谐振频率附近存在较强的SH波(Shear Horizontal)模式，当该模式落入滤波器通带时，往往会造成巨大的波纹(Ripple)，从而影响滤波器件性能；此外，直接在叉指电极102的金属表面生长较厚的温度补偿层103，该温度补偿层103的膜质量容易出问题，比如膜层内(如叉指电极102上端与温度补偿层103相接触的界面104)出现空洞、缝隙等缺陷，这些缺陷会导致器件的Q值下降，同样影响滤波器件性能；而且，生长的温度补偿层103一般还会因膜厚较大，使得在制作过程中厚度会存在一定误差，其中在正常薄膜制备工艺中该误差控制能力与薄膜厚度的绝对值一般呈正比，如生长2μm厚度的薄膜，该薄膜一致性一般为±5％，即约±100nm的误差；而该误差对器件的谐振频率、有效耦合系数(effective coupling coefficient，k2 eff)等都有较大影响。
为此，现有技术中提及通过改变压电衬底以一定程度地抑制杂波模式，但显然其并不能消除该杂波模式影响，而且，对于如梯形滤波器的类似架构，因其往往由若干个谐振器组成，采用该方法实际上也难以同时抑制所有谐振器的杂波模式；此外，现有技术还提及通过对温度补偿层进行平坦化处理，以达到特定的厚度位置，从而去除空洞，但是这种方法对于靠近如叉指电极的位置的缺陷作用极为有限；而且，温度补偿层厚度的变化对器件性能具有较大的影响，若从制造工艺控制尽可能生长厚度均一性好的膜层，其工艺难度较大，而且当谐振频率越高时，性能变化对膜厚的灵敏度越加明显，工艺操作难度也相应进一步提升。
为解决现有技术中诸如Buried TC-SAW器件等具有温度补偿层的声波器件结构所存在的上述技术问题至少之一，本公开提供了一种具有温度补偿特性的声波器件结构、滤波器和电子设备。
如图2A-图6所示，本公开的第一方面提供了一种具有温度补偿特性的声波器件结构，其中，包括压电层、温度补偿层以及谐振电极层。
压电层作为声波器件结构的谐振结构；
温度补偿层对应于压电层的至少一表面设置，用于为压电层提供温度 补偿效果；
谐振电极层设置于压电层的表面上，用于与压电层相配合产生谐振效应；其中，谐振电极层包括填充位，填充位暴露压电层的表面，用于填充或注入平坦化材料形成与谐振电极层的一表面持平的平坦化层。
如图2A所示，声波器件结构可以包括压电层201、温度补偿层204以及谐振电极层。其中，压电层201可以作为该声波器件结构的衬底，构成压电衬底。压电层201一般用于产生声波器件结构的谐振功能，该压电层201的制备材料具体可以为氮化铝、氧化锌、铌酸锂或钽酸锂等中至少一种或者至少两种的混合物，以进一步提高压电层201的谐振性能。其中，该压电层201可以为1种或多种不同压电材料所构成的多层压电结构堆栈层。
此外，温度补偿层204可以设置在压电层201的上表面上方，夹设位于二者之间的谐振电极层，用于与该谐振电极层直接接触，以实现补偿压电层201的谐振频率随温度的变化。该温度补偿层204制备材料可以为介质材料，具体可以为二氧化硅(SiO2)、磷硅玻璃等，或者也可以是其它具有正频率温度系数的材料。其中，该温度补偿层204也可以设置在该压电层201的下表面上，即与谐振电极层不直接接触。
如图2B所示，仿真基础为压电层201的压电材料为128-YX LiNbO3，且谐振电极层选择为金属铜Cu的叉指电极层，且温度补偿层选择厚度为0.3λ的SiO2材料(一般二氧化硅的厚度和叉值电极的周期存在一定对应关系，λ是叉指电极排列方向上的周期，例如band8(930MHz)的滤波器，叉指电极排列方向上的周期λ约为3.8um，具体可以参照图2G所示)。因此，当如图2A所示的温度补偿层204的制备材料与平坦化层203的制备材料相同且均为SiO2时，实际上该声波器件结构的结构形式可以参照图1所示的具有结构缺陷的Buried TC-SAW器件结构的组成形式，即温度补偿层制备材料为SiO2，且其全覆盖谐振电极层的暴露表面；此时，对应于图2B所示的实曲线，SiO2材料的温度补偿层103具有典型的谐振器的阻抗特性，其最小、最大值对应的频率分别为谐振频率fs和反谐振频率fp；在温度变化时，因压电、电极层等材料的杨氏模量变化(杨氏模量变化会导致材料声速变化)以及各层存在的热膨胀特性，fs和fp会发生偏移。因此， 温度补偿层一般具有随频率正向变化的杨氏模量关系，这与如压电层101和叉指电极102的电极刚好相反，因此可以补偿频率随温度的变化。但如前述所言，图1所示的该SiO2材料的温度补偿层103的声波器件结构具有显著的技术缺陷难以克服。
谐振电极层覆盖在压电层201的表面上，与该压电层201的表面直接接触。为保证与压电层201之间的谐振效果，该谐振电极层的制备材料可以选择具有良好导电特性的金属或者金属合金材料，具体可以为与半导体工艺相兼容的铝、钼、铜、金、铂、银、镍、铬、钨等中至少之一种的金属材料或者至少两种的金属合金材料，谐振电极层也可以是上述至少一种金属材料的多层结构电极。
相对于该谐振电极层与压电层201的接触，谐振电极层上的填充位可以是一开放结构，具体可以是该谐振电极层上相对的缝隙、开孔或者开口等，用于相对于该谐振电极层暴露该压电层201的表面，防止谐振电极层将压电层201完全覆盖。因而，可以借助该填充位填充或者注入平坦化材料，以形成相对于该谐振电极层和压电层201的平坦化层203，该平坦化层203与该谐振电极层的上表面持平，即二者不会与压电层201发生接触的另一侧表面高度持平，具有平坦化效果。
平坦化层203的平坦化材料为介质材料，厚度上可以与谐振电极层的厚度相同或相近，但需要满足该平坦化层203和谐振电极层相对于压电层201的背表面相持平，形成平坦化界面。相对于传统的TC-SAW结构，本公开实施例的该平坦化层203的平坦化材料具体为不同于温度补偿层204的高声速的介质材料，具体可以为氮化硅(即SiN)、氮化铝等。
如图2B所示，仿真基础为压电层201的压电材料为128-YX LiNbO3，且谐振电极层选择为金属铜Cu的叉指电极层，且温度补偿层选择厚度为0.3λ的SiO2材料。因此，当如图2A所示的温度补偿层204的制备材料为SiO2，且平坦化材料为SiN时，实际上该声波器件结构的结构形式可以参照图2A所示的本公开实施例的声波器件结构的组成形式，即温度补偿层204只能够覆盖谐振层的上端面，其侧表面被平坦化层203所覆盖。此时，对应于图2B所示虚曲线，温度补偿谐振频率位置对应等效阻抗的最小值因平坦化层203的平坦化材料SiN(SiN材料的平坦化层203可以提高器 件整体的声速，对应的谐振频率也更高)的声速高于SiO2材料，虚曲线表示的SiN平坦化层203结构的谐振频率更高，高于反谐振频率fp的位置，两种结构都存在杂波模式SH波。但是，由于器件阻抗曲线的各个谐振点的谐振频率fs和反谐振频率fp以及杂波模式频率与器件结构以及所用材料相关，SiN材料的平坦化层203结构其对fs、fp偏移的程度和杂波模式频率偏移的程度明显不同于SiO2材料的温度补偿层的全覆盖效果，因此，不同的杂波模式距离谐振频率fs和反谐振频率fp更远。可见，对于一般有谐振和反谐振作用构成滤波器通带的梯形滤波器结构，借助于基于SiN材料的上述平坦化层203结构可以将该杂波模式移至更高频率，有助于减弱该波对滤波器通带及滚降(roll-off)的影响。因此，加入基于SiN材料的平坦化层203，可减小因杂波模式带来的通带或滚降ripple。
进一步地，如图2C和图2D所示，对于温度补偿层材料均为SiO2时，不同金属占空比mr和不同温度补偿层厚度h SiO2对器件的有效耦合系数k2 eff影响，如图2C和图2D所示，越靠近左侧越小，越靠近右侧越大。可知，随着温度补偿层的厚度h SiO2从0.15λ到0.5λ的增大，有效耦合系数k2 eff呈下降趋势。随着金属占空比mr从0.3到0.75的变化，有效耦合系数k2 eff则有先增大再减小的趋势。因此，设计基于该声波器件结构的滤波器时，这两个参数的值都有可能在图中的变化范围内，但整体上，如图2D所示，本公开实施例的采用平坦化层203且其使用SiN材料时，声波器件结构的有效耦合系数k2 eff更高，显然，该平坦化层203的结构设计能够助于设计更大带宽的滤波器。
如图2E和图2F所示，不同金属占空比mr情况时，器件的谐振器率fs随温度补偿层的厚度h SiO2变化的关系仿真图，其中，图2E所示声波器件结构对应于图1所示的传统器件结构，平坦化层的材料与温度补偿层的材料一致且均为SiO2，图2F所示声波器件结构对应于图2A所示的本公开实施例的器件结构，平坦化层的材料选择SiN，且温度补偿层204的材料可以选择为SiO2。可见，在固定占空比参数的情况下，谐振频率fs会随温度补偿层的厚度h SiO2基本上都呈现先增大后减小的趋势；但是，若使用较薄厚度h SiO2的温度补偿层，温度补偿效果较差，器件结构随温度的变化将更加敏感。因此，对于插损、滚降、抑制等要求严格的滤波器， 一般需要采用较厚的温度补偿层以减小压电层201的温度对频率的影响。
需要说明的是，如前述所言，较厚的温度补偿层在制造过程中实际上难以保证整个晶圆厚度的一致性，这就往往会导致不同区域层厚的差异(误差)导致频率和有效耦合系数等器件特性发生变化，而且对该温度补偿层的制作工艺提出了严格的要求，以尽可能控制生长厚度均一性好的膜层，直接造成温度补偿的制备工艺难度较大；此外，当谐振频率fs越高时，器件性能变化对膜厚的灵敏度越加明显，进一步地加大了工艺操作难度。
然而，如图2F所示，在本公开实施例的采用SiN作平坦化层203的制备材料时，相对于横坐标为温度补偿层厚度hSiO2(λ)的在一般所处的0.3-0.4的区间内，对应不同mr的五条曲线中，左侧曲线组位于该区间内的曲线段明显较右侧曲线更为平滑，即谐振频率fs随温度补偿层204的厚度h SO2变化较为平滑(具体可以参照相应的曲线斜率)，也即该SiN材料的平坦化层203可有效降低频率的变化灵敏度。
如前述所言，如图1所示直接在金属层上生长温度补偿层的传统结构。其直接在金属表面生长的较厚的温度补偿层的膜质量容易出问题，比如膜层内尤其在温度补偿层和电极金属紧邻的位置104容易出现空洞、缝隙等。这些缺陷将会直接导致器件的Q值下降，同样影响滤波器件性能。
然而，为保持平坦化层203与谐振电极层的单侧表面的持平效果，在完成平坦化层203和谐振电极层的制备工艺之后，还需要对该谐振电极层和平坦化层203的对应单侧面同时作平坦化处理，这就使得二者紧邻的位置所出现的空洞、缝隙等缺陷被通过平坦化工艺去除。因此，本公开实施例的上述具有单侧表面持平效果的上述平坦化层203和谐振电极层的结构设计能够避免传统的空洞、缝隙等缺陷的影响。此外，在温度补偿层204与平坦化层203和谐振电极层的该单侧表面相接触的情况下，温度补偿层204对该单侧表面的平坦度也有较高要求，以求通过良好的平坦表面接触可提高器件的Q值，提升器件滤波性能。换言之，上述平坦化层203和谐振电极层的结构设计能够显著提高器件Q值，保证器件性能。具体地，该平坦化层203用的制备材料一般也是具有杨氏模量随温度负向变化的材料，如SiN，因此一般完全无温度补偿作用；而由于器件振动的区域在压电层的表面，温度补偿层最好要与压电层表面或者与压电层表面直接接触的谐 振电极层直接接触，才能更好地起到温度补偿效果。
因此，通过上述与谐振电极层的表面持平的平坦化层203，使得该声波器件结构能够有效减少因工艺缺陷导致的温度补偿层界面的空隙、缝隙等问题，同时可以通过该平坦化层203将谐振频率附近的寄生杂波模式远离主谐振峰，提高该器件的整体有效耦合系数，降低温度补偿层影响频率的灵敏度。
如图2A、图2G和图2H所示，根据本公开的实施例，谐振电极层包括第一叉指电极221和第二叉指电极222。
第一叉指电极221具有第一母线和连接该第一母线的多个第一叉指；
第二叉指电极222具有第二母线和连接该第二母线的多个第二叉指，
其中，多个第二叉指与多个第一叉指在压电层的表面上相互平行交错形成叉指效果。
如图2G和图2H所示，第一叉指电极221与第二叉指电极222之间形成叉指交错的效果，其中，第一叉指电极221可以作为谐振效应的输入电极，同时第二又指电极222可以作为相应的输出电极，从而使得该谐振电极层在该压电层201的表面上呈现声表面波的谐振形式，具体可以参照SAW器件的谐振方式。其中，该第一叉指电极221和第二叉指电极222借助于其各自的母线和多个又指在该压电层201的表面上的交错分布，能够形成第一叉指电极221和第二叉指电极222二者之间的空隙。这些空隙均可以作为上述的填充位。
因此，能够使得本公开实施例的上述声波器件结构应用于基于声表面波的器件中，提供更高更稳定的器件性能。
如图2A、图2G和图2H所示，根据本公开的实施例，第一叉指电极和第二叉指电极在平行交错的结构关系中所形成的间隙为填充位；或者谐振电极层与压电层之间的有效谐振区域所对应的第一叉指电极和第二叉指电极之间的间隙为填充位。
如图2G所示，第一叉指电极221的第一母线和第二叉指电极222的第二母线之间的压电层201的表面区域上，由多个第一叉指和多个第二叉指相互交错所形成的暴露压电层201表面的全部空隙可以作为填充位，以实现平坦化材料的填充，并形成位于这些空隙之间并与相邻叉指侧表面接 触的平坦化层203。此时，对于第一母线和第二母线之间的叉指电极的交错重叠区域和非重叠区域对应的间隙全部作为平坦化层203所处的区域。
如图2H所示，相对于如图2G所示的声波器件结构，平坦化层203′可以只覆盖第一叉指电极221和第二叉指电极222的叉指的重叠区域，即二者与压电层201之间具有谐振效应的有效区域的叉指之间的间隙作为填充位。由于压电层201的谐振效应主要在该有效区域内起作用，因此，只需要保证该区域内的温度补偿层204的膜质量和平坦度即可，而填充在该填充位的高声速材料(如SiN)构成的平坦化层203′，由于其与温度补偿层204接触的表面具有良好平滑度，借此将有助于提升谐振有效区的整体声速，与叉值电极的端部形成声速差，在有效将声波限制在有效区域内的同时，抑制横向寄生模式，从而提高器件的Q值。
需要说明的是，上述所提及的第一叉指电极221和第二叉指电极222的叉指的重叠区域实际上并不包括该第一叉指电极221和第二叉指电极222沿叉指电极方向的端部区域，具体可以参照图2H所示。
如图3A和图3B所示，根据本公开的实施例，谐振电极层302为设置于压电层301表面上的平面薄膜电极层，填充位包括至少一个填充孔，至少一个填充孔穿设平面薄膜电极层，暴露压电层301的表面。
设置于压电层301一表面上的谐振电极层302在作为平面薄膜电极层的情况下，可以配合另一位于该压电层301的另一表面设置的下电极层，使得该谐振电极层302与压电层301呈现体声波的谐振形式，具体可以参照BAW器件的谐振方式。该填充位所具有的填充孔可以为多个，且可以阵列排布的形式分布在该谐振电极层302上，每个填充孔均为穿设该谐振电极层302的通孔，能够使得压电层301表面暴露，以用于填充相应的平坦化材料，如SiN，以形成基于这些填充孔的平坦化层303。
借此，可以在实现上述如图2A所示的有益效果基础上，能够使得本公开实施例的上述声波器件结构应用于基于体表面波的器件中，提供更高更稳定的器件性能。
如图4A-图4C所示，根据本公开的实施例，声波器件结构还包括第一保护层和/或第二保护层。
第一保护层对应于压电层的一表面，设置于相应的温度补偿层的一表 面上；
第二保护层对应于压电层的另一表面，设置于谐振电极层和平坦化层所形成的持平表面上。
对于本公开实施例的声波器件结构，具体可以包括压电层401、谐振电极层402、平坦化层403和温度补偿层404，谐振电极层402可以是如图2A、图2G和图2H所示的叉指电极层。其中，该谐振电极层402和平坦化层403的单侧表面具有持平的平坦化效果。此外，为起到防水、隔离、密封等器件保护作用，该声波器件结构还可以具有相应的保护层设置在该声波器件结构中。其中，该保护层一般覆盖在温度补偿层4表面、谐振电极层402和平坦化层403所具有平坦化效果的单侧表面上，或者上述两个表面兼有之，从而对该温度补偿层提供保护隔离作用，以保护该层不易进水气等。
具体地，如图4A所示，该声波器件结构在压电层401表面形成具有单侧平坦化表面的谐振电极层402和平坦化层403，并在该谐振电极层402和平坦化层403的单侧平坦化表面上形成温度补偿层404，而且，在该温度补偿层404的表面上形成保护层405；如图4B所示，该声波器件结构在压电层401表面形成具有单侧平坦化表面的谐振电极层402和平坦化层403，并在该谐振电极层402和平坦化层403的单侧平坦化表面上直接形成保护层451，而且，在该压电层401的另一表面上形成温度补偿层441，并进一步在该温度补偿层441的下表面上形成保护层452；如图4C所示，该声波器件结构在压电层401表面形成具有单侧平坦化表面的谐振电极层402和平坦化层403，并在该谐振电极层402和平坦化层403的单侧平坦化表面上形成温度补偿层442，在该温度补偿层442的上表面上进一步形成保护层453，而且，在该压电层401的另一表面上形成温度补偿层443，并进一步在该温度补偿层443的下表面上形成保护层454……其中，相应地还可以由其他实施案例的保护层设计，具体不作限制。
借助于上述保护层的设计，能够显著提高器件的使用寿命，保证上述“有效减少因工艺缺陷导致的温度补偿层界面的空隙、缝隙等问题，同时可以通过该平坦化层203将谐振频率附近的寄生杂波模式远离主谐振峰，提高该器件的整体有效耦合系数，降低温度补偿层影响频率的灵敏度”的 技术效果，提高器件结构稳定性。
需要说明的是，该声波器件结构还可以具有位于谐振电极层上方用于抑制横向模式的边缘反射层、连接叉指电极并引出至外部结构的金属连接层等，具体可以依据器件结构的实际需要进行调整设计，在此不作赘述。其中，该声波器件结构在压电层的厚度较薄时，为加强结构稳定性，提高器件性能，还可以具有衬底结构，该衬底结构的制备材料可以为硅、石英以及氧化铝等中的一种，或者多种材料的堆栈结构。此外，对于本公开实施例所提及的各种电极层的制备材料也可以与上述的谐振电极层的制备材料相一致，在此也不再赘述。
如图5A和图5B所示，根据本公开的实施例，压电层501包括电极槽，电极槽凹设于压电层501的表面，用于设置谐振电极层502。
对于本公开实施例的声波器件结构，具体可以包括压电层501、谐振电极层502和温度补偿层504，谐振电极层502可以是如图2A、图2G和图2H所示的叉指电极层。其中，由于电极槽凹设在压电层501的表面上，使得该谐振电极层502在形成于该电极槽中时，会嵌入在该压电层501上，构成嵌入式电极，实现与该压电层501更为稳定的结构结合效果。而且，借助于该凹设在压电层501表面上的电极槽，可以在垂直方向上实现对该声波器件结构的尺寸压缩。
此外，上述的嵌入式电极的结构在嵌入至压电层501中部分时，相对于在压电层表面的单方向接触的情况，可以实现多个方向的压电接触，由于逆压电效应是通过电极中的信号，激励压电层在输入电极产生振动，声波传递至输出电极，并依靠压电效应再在输出电极产生输出信号，实现电-声-电的能量转换，因此，谐振电极层502与压电层501之间更大的接触面积能够进一步激发压电特性，提升有效耦合系数，从而进一步提供器件性能。
如图5A所示，根据本公开的实施例，其中，电极槽的深度小于谐振电极层502的厚度。
对于本公开实施例的声波器件结构，具体可以还包括平坦化层503。如图5A所示，当电极槽的深度小于该谐振电极层502的厚度时，说明该谐振电极层502部分地嵌入在该压电层501的表面上，另一部分则凸出于 该压电层501的表面之外，如此，便可以通过外凸于该压电层501的表面之外的谐振电极层502的部分将该压电层501的表面进行分割，形成相对于该谐振电极层502的空隙作为平坦化层503的填充位。对该填充位进行平坦化材料的填充，并在完成平坦化材料的填充之后，对平坦化层和谐振电极层的结合体进行平坦化处理，最终形成平坦化层503和谐振电极层502。
如此便可以更大地实现压电层501与谐振电极层502之间的接触面积，更好的提升器件的有效耦合系数，相应提升器件整体性能。而且如图5A所示，借助于该凹设在压电层501表面上的电极槽，可以在垂直方向上实现对该声波器件结构的尺寸压缩。
如图5B所示，根据本公开的实施例，电极槽的深度等于谐振电极层502的厚度，未设置电极槽的压电层501的表面形成填充位。
对于本公开实施例的声波器件结构，具体可以还包括平坦化层503′。如图5B所示，当电极槽的深度等于该谐振电极层502的厚度时，说明该谐振电极层502已经完全嵌入在该压电层501的表面中。如此，便可以相对地形成该压电层501关于谐振电极层502的图形。在该图形中相对设置的谐振电极层502的压电层501所暴露的压电表面区域可以用于构成平坦化层503′的填充位。对该填充位进行平坦化材料的注入或植入工艺，使得相应的平坦化材料能够以高浓度掺杂形式进入该压电层501的暴露表面中，并形成一设定厚度的掺杂层，作为该平坦化层503′。
此时，由于电极槽的深度与谐振电极层502相同，使得谐振电极层502全部到压电层501中，因此可先在生长完谐振电极层502之后直接做平坦化处理，之后进行平坦化材料在暴露压电层501表面的注入或植入操作，而不再需要再对平坦化层503′作平坦化处理，同样可以形成平坦化层503′和谐振电极层502的单侧表面的平坦化。如此，可以进一步更大地实现压电层501与谐振电极层502之间的接触面积，更好的提升器件的有效耦合系数，相应提升器件整体性能，进一步在垂直方向上压缩了器件结构的尺寸大小。其中，只要能够保证温度补偿层与谐振电极层或者压电层之间的接触效果，实现相应的温度补偿效应即可。
因此，如图5A和图5B所示，借助于该凹设在压电层501表面上的 电极槽，可以在垂直方向上实现对该声波器件结构的尺寸压缩，有利于该声波器件结构的小型化、集成化和精密化，且相对于将谐振电极平铺在该压电层表面上的结构设计，能够显著改善的压电层501和谐振电极层502之间的结构稳定性，以及通过增大压电接触面积得到更好的器件性能。
综上所述，通过本公开实施例的上述具有温度补偿特性的声波器件结构，可以实现将谐振频率附近的寄生模式挪至远离的频率，并且显著提高器件的有效耦合系数，同时有效降低温度补偿层影响频率的灵敏度，并减小因工艺缺陷导致的温度补偿层内的空隙、缝隙等问题，还能够加强结构稳定性，压缩器件结构垂直尺寸，减少结构器件的制备成本，具体在此不作赘述。
本公开的第二方面提供了一种上述的具有温度补偿特性的声波器件结构的制备方法。如图2A所示，在本公开上述声波器件结构的制作流程工艺中，一般是先生长并图形化出谐振电极层结构，然后在压电层和谐振电极层表面生长平坦化层，并作平坦化处理如化学机械抛光(CMP)等磨平二者的单侧表面，直至谐振电极层达到预设厚度，最后再生长温度补偿层到最终器件结构上。
此外，该谐振电极层(如叉指电极)和平坦化层的生长顺序也可以调换，只需保证最终两层具有单侧持平的光滑表面，以避免会影响后面温度补偿层生长的成膜质量即可。其中，对二者单侧表面进行平坦化的处理，可以作化学机械抛光(CMP)工艺，一般可以保证上述两层获得至少一侧相互持平的状态。因此，采用在谐振电极层和平坦化层单侧形成平滑表面也有助于随后生长高质量的温度补偿层，以及控制温度补偿层的表面平坦度，减少器件缺陷，从而显著提高Q值，而且通过对平坦化层的平坦化处理，使得其不会阻隔温度补偿层与电极层的端面之间的接触，借助于相应的平坦化表面，还可以使得温度补偿层的表面平整度在制备工艺流程中得到更容易控制，从而显著降低制备成本。
其中，对于上述本公开实施例的声波器件结构的制备方法，其具体工艺步骤可以根据实际的声波器件结构的不同而作相应的调整，具体不作赘述。
如图6所示，本公开的第三方面提供了一种滤波器，其中，包括主路 径、至少一个并联路径和至少一个谐振器。
主路径一端连接输入端口Tx，另一端连接输出端口Ant；
至少一个并联路径连接在主路径上，与主路径保持并联关系；
至少一个谐振器连接于至少一个并联路径中的一个并联路径上，其中，至少一个谐振器中的至少一个谐振器包括上述的具有温度补偿特性的声波器件结构。
如图6所示，该滤波器为由多个声波谐振器单元所构成的梯形滤波器，具体由若干串联支路谐振器模块601和并联支路谐振器模块602搭建而成，具体地，串联支路谐振器模块601具有多个在主路径上相互串联的声波谐振器611、612和613，并联支路谐振器模块602则具有多个分别在各自对应并联路径上连接的声波谐振器621、622和623，以此构成相应的梯形滤波器结构。
其中，对于该滤波器而言，由于其并联谐振器的反谐振频率fp点一般落在通带内，同时串联谐振器的谐振频率fs点一般位于该通带内，即并联支路谐振器模块602的各个并联谐振器的反谐振频率和串联支路谐振器模块601的各个串联谐振器的谐振频率会出现在该滤波器的通带内。因此，作为该滤波器的一优选实施案例，至少可以对并联支路谐振器模块602中的一个或多个并联谐振器实施上述图2A-图6描述的具有温度补偿特性的声波器件结构，从而能够将滤波器的高频杂波模式移至更高频位置，以避免杂波模式产生对滤波器通带的影响。需要说明的是，也可以对串联支路谐振器模块601中的串联谐振器的一个或多个上述本公开实施例的具有温度补偿特性的声波器件结构。
因此，对于一般有谐振和反谐振作用构成滤波器通带的滤波器结构，可以借助于基于SiN材料的上述平坦化层结构，将该杂波模式移至更高频率，有助于减弱该波对滤波器通带及滚降(roll-off)的影响。因此，加入基于SiN材料的平坦化层，可有效减小因杂波模式带来的通带或滚降ripple。
本公开的第四方面提供了一种电子设备，其中，包括上述的滤波器。其中，该电子设备可以是手机、笔记本、平板电脑以及POS机、车载电脑等可移动或固定式的计算机设备，也可以其他具有智能信息处理功能的其他可以采用高频高带宽的4G、5G等通信电子设备。
至此，已经结合附图对本公开实施例进行了详细描述。
以上所述的具体实施例，对本发明的目的、技术方案和有益效果进行了进一步详细说明，所应理解的是，以上所述仅为本发明的具体实施例而已，并不用于限制本发明，凡在本发明的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (10)

  1. 一种具有温度补偿特性的声波器件结构，其中，包括：
    压电层，作为所述声波器件结构的谐振结构；
    温度补偿层，对应于所述压电层的至少一表面设置，用于为所述压电层提供温度补偿效果；
    谐振电极层，设置于所述压电层的表面上，用于与所述压电层相配合产生谐振效应；其中，所述谐振电极层包括：
    填充位，暴露所述压电层的表面，用于填充或注入平坦化材料形成与所述谐振电极层的一表面持平的平坦化层。
  2. 根据权利要求1所述的声波器件结构，其中，所述谐振电极层包括：
    第一叉指电极，具有第一母线和连接该第一母线的多个第一叉指；
    第二叉指电极，具有第二母线和连接该第二母线的多个第二叉指，其中所述多个第二叉指与所述多个第一叉指在所述压电层的表面上相互平行交错形成叉指效果。
  3. 根据权利要求2所述的声波器件结构，其中，
    所述第一叉指电极和第二叉指电极在所述平行交错的结构关系中所形成的间隙为所述填充位；或者
    所述谐振电极层与所述压电层之间的有效谐振区域所对应的所述第一叉指电极和第二叉指电极之间的间隙为所述填充位。
  4. 根据权利要求1所述的声波器件结构，其中，所述谐振电极层为设置于所述压电层表面上的平面薄膜电极层，所述填充位包括：
    至少一个填充孔，穿设所述平面薄膜电极层，暴露所述压电层的表面。
  5. 根据权利要求3或4所述的声波器件结构，其中，还包括：
    第一保护层，对应于所述压电层的一表面，设置于相应的所述温度补偿层的一表面上；和/或
    第二保护层，对应于所述压电层的另一表面，设置于所述谐振电极层和所述平坦化层所形成的持平表面上。
  6. 根据权利要求3或4所述的声波器件结构，其中，所述压电层包 括：
    电极槽，凹设于所述压电层的表面，用于设置所述谐振电极层。
  7. 根据权利要求6所述的声波器件结构，其中，所述电极槽的深度小于所述谐振电极层的厚度。
  8. 根据权利要求6所述的声波器件结构，其中，所述电极槽的深度等于所述谐振电极层的厚度，未设置所述电极槽的所述压电层的表面形成所述填充位。
  9. 一种滤波器，其中，包括：
    主路径，一端连接输入端口，另一端连接输出端口；
    至少一个并联路径，连接在所述主路径上，与所述主路径保持并联关系；
    至少一个谐振器，连接于所述至少一个并联路径中的一个并联路径上，其中，所述至少一个谐振器中的至少一个谐振器包括权利要求1-8中任一项所述的具有温度补偿特性的声波器件结构。
  10. 一种电子设备，其中，包括权利要求9所述的滤波器。
PCT/CN2023/084455 2022-06-30 2023-03-28 具有温度补偿特性的声波器件结构、滤波器和电子设备 WO2024001352A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202210776171.8 2022-06-30
CN202210776171.8A CN115133901A (zh) 2022-06-30 2022-06-30 具有温度补偿特性的声波器件结构、滤波器和电子设备

Publications (1)

Publication Number Publication Date
WO2024001352A1 true WO2024001352A1 (zh) 2024-01-04

Family

ID=83381859

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/084455 WO2024001352A1 (zh) 2022-06-30 2023-03-28 具有温度补偿特性的声波器件结构、滤波器和电子设备

Country Status (2)

Country Link
CN (1) CN115133901A (zh)
WO (1) WO2024001352A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115133901A (zh) * 2022-06-30 2022-09-30 开元通信技术（厦门）有限公司 具有温度补偿特性的声波器件结构、滤波器和电子设备

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11186866A (ja) * 1997-12-22 1999-07-09 Kyocera Corp 弾性表面波装置及びその製造方法
JP2006270608A (ja) * 2005-03-24 2006-10-05 Japan Radio Co Ltd 弾性波デバイスの製造方法
CN107317560A (zh) * 2017-05-11 2017-11-03 华南理工大学 一种温度补偿表面声波器件及其制备方法
CN111800107A (zh) * 2019-04-05 2020-10-20 厦门市三安集成电路有限公司 表面弹性波器件及其制造方法
CN112803911A (zh) * 2021-01-05 2021-05-14 无锡市好达电子股份有限公司 一种具有温度补偿功能的声表面波换能器的制备方法
CN115133901A (zh) * 2022-06-30 2022-09-30 开元通信技术（厦门）有限公司 具有温度补偿特性的声波器件结构、滤波器和电子设备

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11186866A (ja) * 1997-12-22 1999-07-09 Kyocera Corp 弾性表面波装置及びその製造方法
JP2006270608A (ja) * 2005-03-24 2006-10-05 Japan Radio Co Ltd 弾性波デバイスの製造方法
CN107317560A (zh) * 2017-05-11 2017-11-03 华南理工大学 一种温度补偿表面声波器件及其制备方法
CN111800107A (zh) * 2019-04-05 2020-10-20 厦门市三安集成电路有限公司 表面弹性波器件及其制造方法
CN112803911A (zh) * 2021-01-05 2021-05-14 无锡市好达电子股份有限公司 一种具有温度补偿功能的声表面波换能器的制备方法
CN115133901A (zh) * 2022-06-30 2022-09-30 开元通信技术（厦门）有限公司 具有温度补偿特性的声波器件结构、滤波器和电子设备

Also Published As

Publication number Publication date
CN115133901A (zh) 2022-09-30

Similar Documents

Publication Publication Date Title
JP4589306B2 (ja) 電気音響構成素子および製造方法
US7151424B2 (en) Boundary acoustic wave device
CN102422534B (zh) 天线共用器
JP3387469B2 (ja) 弾性表面波装置及び弾性表面波フィルタ
US11349450B2 (en) Symmetric transversely-excited film bulk acoustic resonators with reduced spurious modes
US20170288629A1 (en) Solidly mounted layer thin film device with grounding layer
CN113708739B (zh) 一种声波滤波器
CN107404302B (zh) 具有用于抑制假信号响应的吸收层的复合表面声波saw装置
US20190305748A1 (en) Elastic wave device
CN110798167A (zh) 声波器件及其制作方法
CN102017407A (zh) 弹性边界波装置
WO2024001352A1 (zh) 具有温度补偿特性的声波器件结构、滤波器和电子设备
CN113872555A (zh) 压电谐振器及其制作方法
WO2024077955A1 (zh) 一种多传输零点的声表面波滤波器及信号处理电路
CN110572138A (zh) 一种滤波装置及其制作方法
WO2007145056A1 (ja) 弾性表面波装置
CN210405249U (zh) 一种滤波装置
CN109039298B (zh) 声表面波器件及其制作方法
US10840875B2 (en) Surface acoustic wave devices using beryllium conductors
CN115567027B (zh) 换能装置、声表面波谐振装置及其形成方法、滤波装置
US20220407494A1 (en) Acoustic wave device and method of manufacturing the same
CN215871344U (zh) 一种声波器件以及一种滤波装置
CN115378392A (zh) 底电极激发式声表面波器件制备方法
CN115567022A (zh) 一种声波器件、滤波装置及声波器件的制备方法
JP5877032B2 (ja) 弾性波装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23829543

Country of ref document: EP

Kind code of ref document: A1