WO2022134860A1 - 一种新型fbar滤波器及其制备方法 - Google Patents

一种新型fbar滤波器及其制备方法 Download PDF

Info

Publication number
WO2022134860A1
WO2022134860A1 PCT/CN2021/127793 CN2021127793W WO2022134860A1 WO 2022134860 A1 WO2022134860 A1 WO 2022134860A1 CN 2021127793 W CN2021127793 W CN 2021127793W WO 2022134860 A1 WO2022134860 A1 WO 2022134860A1
Authority
WO
WIPO (PCT)
Prior art keywords
substrate
layer
bottom electrode
air cavity
novel
Prior art date
Application number
PCT/CN2021/127793
Other languages
English (en)
French (fr)
Inventor
李国强
衣新燕
赵利帅
欧阳佩东
刘红斌
张铁林
Original Assignee
华南理工大学
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 华南理工大学 filed Critical 华南理工大学
Publication of WO2022134860A1 publication Critical patent/WO2022134860A1/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
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
    • 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
    • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material

Definitions

  • the invention belongs to the technical field of radio frequency filtering, and particularly relates to a novel FBAR filter and a preparation method thereof.
  • CMOS complementary metal oxide semiconductor
  • the air-gap FBAR filter is currently monopolized by foreign patents, and this technical route cannot be used, but the performance of the FBAR filter of this structure still has room for improvement.
  • Figure 1 it includes a substrate, an air cavity on the substrate, A bottom electrode, a piezoelectric layer and a top electrode are sequentially fabricated on the substrate across the air cavity.
  • the piezoelectric film covers the boundary of the pit on the substrate and exposes the leading end of the bottom electrode.
  • a layer of metal is deposited on the piezoelectric film. film, and the top electrode pattern is etched.
  • a release window is etched on the piezoelectric layer by dry etching to partially expose the sacrificial layer.
  • the sacrificial layer is released from the engraved release window, and the FBAR across the air cavity on the substrate is fabricated.
  • this method of releasing the sacrificial layer will leave a lot of release channel holes on the piezoelectric layer.
  • the damage of the film is very large, which leads to the easy collapse of the cavity structure, and the low Q value and electromechanical coupling coefficient, and the large insertion loss, which affects the performance of the device.
  • the purpose of the present invention is to provide a novel FBAR filter and a preparation method thereof.
  • the novel FBAR filter provided by the present invention is a thin-film bulk acoustic wave filter.
  • the purpose of the present invention is to overcome the defects of the prior art, and propose a novel FBAR filter and a preparation method thereof.
  • the preparation method no sacrificial layer is needed in the preparation process, which reduces the damage to the piezoelectric film, thereby overcoming the problem of adverse effects on the filter structure during the process of removing the sacrificial layer, and this kind of lining
  • the method of etching a groove on the bottom and preparing a piezoelectric film in the groove can effectively reduce the stress of the piezoelectric film, suppress the clutter, reduce the energy loss, improve the quality of the piezoelectric film, and reduce the reduction of the film bulk acoustic wave resonator.
  • the insertion loss, the improvement of the Q value and the electromechanical coupling coefficient, will become a solution for RF filters suitable for future high frequency and high power occasions.
  • the object of the present invention is achieved by at least one of the following technical solutions.
  • the novel FBAR filter provided by the present invention is formed by cascading n resonators, where n is an integer and n ⁇ 1; the resonator includes a support substrate, an air cavity support layer, a bottom electrode, a seed layer, and a piezoelectric film
  • the structure layer, the top electrode and the bottom electrode are led upward; there are two air cavity support layers, which are respectively stacked on the support substrate, the bottom electrode is respectively connected with the two air cavity support layers, and the bottom electrode, the air cavity support layer and the
  • the support substrate encloses a cavity; the seed layer is stacked on the bottom electrode and the air cavity support layer; the piezoelectric film structure layer and the top electrode are stacked on the seed layer in sequence; the bottom electrode is connected to the bottom electrode .
  • the supporting substrates are silicon substrates, sapphire substrates, silicon carbide substrates, gallium nitride substrates, aluminum nitride substrates, AlxGa1-xN buffer layer substrates, glass substrates, organic polymer materials One or more of flexible substrates, etc.
  • the material of the air cavity support layer is an insulating material, and the insulating material is more than one of SiO 2 , AlN, and Si 3 N 4 ; the thickness of the air cavity support layer is 0.3-3 ⁇ m.
  • the material of the support layer is an insulating material; the material of the support layer is a material with high dielectric constant such as silicon dioxide, silicon nitride, aluminum nitride, and gallium nitride.
  • the material of the bottom electrode and the top electrode is one or more of Al, Mo, W, Pt, Cu, Ag, Au, ZrN, etc.; the thickness of the bottom electrode and the top electrode are both 20-500 nm.
  • the seed layer is a sputtered polycrystalline piezoelectric material or a single crystal piezoelectric material; the material of the seed layer is one or more of AlN, ZnO, lithium niobate and lithium tantalate, etc.; The thickness of the seed layer is 5-100 nm.
  • the piezoelectric film structure layer is one or more of a high-quality single-crystal piezoelectric film grown by epitaxial growth, a polycrystalline piezoelectric film with a high C-axis orientation grown by sputtering, and a film with piezoelectric properties;
  • the material of the piezoelectric thin film structure layer is one or more of AlN, ZnO, PZT, lithium niobate, lithium tantalate, etc.; the thickness of the piezoelectric thin film structure layer is 0.02 ⁇ m-10 ⁇ m.
  • the novel FBAR filter provided by the invention has a filtering frequency of 10MHz-100GHz.
  • the preparation method of the novel FBAR filter provided by the present invention includes: firstly preparing grooves (the number of grooves can be multiple) by etching on a preparation substrate, then preparing piezoelectric materials in the grooves, and then To prepare the bottom electrode, before preparing the bottom electrode, first prepare a thin seed layer, prepare the air cavity support layer, take another support substrate, bond the support substrate with the preparation substrate and the structure above, and then The preparation substrate is removed, the piezoelectric material is exposed, the top electrode is prepared on the piezoelectric material, and the bottom electrode is drawn out, and finally a filter formed by cascading a plurality of basic resonators is prepared.
  • the preparation method of the novel FBAR filter provided by the present invention comprises the following steps:
  • n grooves on the prepared substrate (the number of grooves can be multiple), n is an integer and n ⁇ 1; and then prepare a piezoelectric thin film structure layer (piezoelectric material) in the groove , using the method of epitaxy or sputtering to prepare a seed layer (thin bottom electrode seed layer) on the piezoelectric thin film structure layer, and then prepare and pattern the bottom electrode on the seed layer by sputtering or electron beam evaporation;
  • Two air cavity support layers are prepared on the bottom electrode and the seed layer (insulating material is deposited and patterned as an air cavity support layer), and another support substrate (the substrate can be silicon wafer, sapphire, silicon, sapphire, LiGaO2, GaN, SiC, glass, organic polymer materials, etc.), the support substrate is bonded to the two air cavity support layers and the preparation substrate at the same time, and the bottom electrode, the air cavity support layer and the support substrate form a hollow space.
  • the preparation substrate is removed, and the removal method is mechanical thinning combined with wet etching or dry etching commonly used in the industry;
  • the preparation substrate is removed, the piezoelectric thin film structure layer is exposed, the top electrode is prepared on the piezoelectric thin film structure layer, and the bottom electrode is drawn out (the seed layer is etched with the lead hole on the bottom electrode, the method It can be wet etching or dry etching), and the bottom electrode can be pulled up by electroplating or evaporation sputtering to obtain the novel FBAR filter (a filter formed by cascading multiple resonators).
  • the prepared substrates in step (1) are silicon substrates, sapphire substrates, silicon carbide substrates, gallium nitride substrates, LiGaO 2 substrates, aluminum nitride substrates, and AlxGa1-xN buffer layer substrates , one or more of glass substrates and organic polymer material flexible substrates.
  • step (2) a cavity is engraved in the middle of the side where the support substrate and the air cavity support layer are bonded, and the cavity depth is 0.5-3 microns.
  • the preparation method provided by the invention can prepare the FBAR filter of any frequency, including the FBAR filter in the frequency range from 10MHz to 10GHz.
  • the present invention has the following advantages and beneficial effects:
  • the preparation method provided by the present invention does not need to use a sacrificial layer during the preparation process, thereby reducing the damage to the piezoelectric film, thereby overcoming the problem of adverse effects on the filter structure during the process of removing the sacrificial layer, and the
  • the method of preparing the etching groove on the substrate and preparing the piezoelectric film in the groove can effectively reduce the stress of the piezoelectric film, suppress the clutter, reduce the energy loss, improve the quality of the piezoelectric film, and reduce the bulk acoustic wave of the film.
  • the insertion loss of the resonator, the improvement of the Q value and the electromechanical coupling coefficient, will become a solution for RF filters suitable for future high-frequency and high-power applications.
  • FIG. 1 is a cross-sectional view of an air-gap FBAR in the prior art
  • FIG. 2 is a cross-sectional view of a prepared substrate in an embodiment
  • FIG. 3 is a schematic diagram of etching grooves on a preparation substrate in an embodiment
  • FIG. 4 is a schematic diagram of preparing a piezoelectric thin film in a groove of a preparation substrate in an embodiment
  • FIG. 5 is a schematic diagram of preparing a seed layer and a bottom electrode in an embodiment
  • FIG. 6 is a schematic diagram of depositing a layer of insulating dielectric support layer and patterning in an embodiment
  • FIG. 7 is a schematic diagram of another supporting substrate taken and bonded with the front wafer in the embodiment.
  • FIG. 8 is a schematic diagram of preparing a substrate to remove and prepare a top electrode in an embodiment
  • Fig. 9 is the schematic diagram of the novel FBAR filter obtained after the bottom electrode is prepared in the embodiment.
  • FIG. 10 is a schematic diagram showing the principle of the filter in the ladder cascade structure of resonators in the embodiment.
  • FIG. 11 is an effect diagram showing the low insertion loss and wide passband of the filter manufactured in the embodiment.
  • a new type of FBAR filter is formed by cascaded n resonators, n is a positive integer and n ⁇ 1; as shown in FIG. 9, the resonator includes a support substrate 106, an air cavity support layer 105, and a bottom electrode 104.
  • Each air cavity support layer 105 is connected, and the bottom electrode 104, the air cavity support layer 105 and the support substrate 106 form a cavity; the seed layer is stacked on the bottom electrode 104 and the air cavity support layer 105; the piezoelectric film structure The layer 102 and the top electrode 107 are sequentially stacked on the seed layer 103 ; the bottom electrode lead 108 is connected to the bottom electrode 104 .
  • the supporting substrate 106 is a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, an aluminum nitride substrate, an AlxGa1-xN buffer layer substrate, a glass substrate, and a flexible substrate of organic polymer materials. more than one of the bottoms.
  • the material of the air cavity support layer 105 is an insulating material, and the insulating material is more than one of SiO 2 , AlN, and Si 3 N 4 ; the thickness of the air cavity support layer 105 is 0.3-3 ⁇ m.
  • the bottom electrode 104 and the top electrode 107 are made of one or more of Al, Mo, W, Pt, Cu, Ag, Au, and ZrN; the bottom electrode 104 and the top electrode 107 are both 20-500 nm thick.
  • the seed layer 103 is a sputtered polycrystalline piezoelectric material or a single crystal piezoelectric material; the material of the seed layer 103 is one or more of AlN, ZnO, lithium niobate and lithium tantalate; the seed layer The thickness of 103 is 5-100 nm.
  • the piezoelectric thin film structure layer 102 is one or more of a single crystal piezoelectric thin film grown by epitaxial growth, a polycrystalline piezoelectric thin film with a high C-axis orientation grown by sputtering, and a thin film with piezoelectric properties;
  • the material of the thin film structure layer 102 is one or more of AlN, ZnO, PZT, lithium niobate, and lithium tantalate; the thickness of the piezoelectric thin film structure layer 102 is 0.02 ⁇ m-10 ⁇ m.
  • the resonant frequency of the resonator can be from 10MHz to 10GHz, and then the filter passband can be formed from 10MHz to 10GHz by cascading.
  • FIG. 10 is a schematic diagram showing the principle of the filter in the ladder cascade structure of resonators in the embodiment. As shown in Figure 10, the series resonator and the parallel resonator are cascaded in a ladder to form the most basic filter unit, and the passband is formed through the correspondence of the resonant frequency; in this way, the frequency of the resonator is the thickness of the piezoelectric layer. And the influence of electrode thickness (as shown in Table 1 below), filters with different frequency passbands can be formed.
  • Table 1 is a data table of different resonance points formed by the combination of different piezoelectric layer thicknesses and electrode thicknesses in the embodiment.
  • a preparation method of a novel FBAR filter is as follows:
  • a preparation substrate 110 is taken, and the preparation substrate 110 can be a substrate material of silicon, silicon carbide, sapphire, glass, metal or organic polymer;
  • the groove 101 is etched on the preparation substrate 110 by an etching method
  • the piezoelectric thin film structure layer 102 is prepared by chemical vapor deposition or sputtering in the groove 101.
  • the piezoelectric thin film structure layer 102 is a single crystal or polycrystalline aluminum nitride material, or can be For materials with piezoelectric properties such as ZnO and PZT, the thickness of the piezoelectric thin film structure layer 102 is between 0.02 and 10 microns.
  • the seed layer 103 and the bottom electrode 104 are prepared on the piezoelectric thin film structure layer 102 by chemical vapor deposition, sputtering or electron beam evaporation, and patterning is performed to obtain the desired electrode pattern
  • the electrode material can be more than one of Al, Mo, W, Pt, Cu, Ag, Au, ZrN, and the electrode material can also be other materials with good electrical conductivity, such as non-metallic materials such as graphene, and the electrode thickness is 0.1 nm. to the 500 nm range.
  • an air cavity support layer (insulation layer) 105 is then deposited with a thickness in the range of 0.2-4 microns, and then polished by mechanical polishing and patterned etching to obtain the air cavity support shown in FIG. 6. layer 105;
  • FIG. 7 As shown in FIG. 7, another piece of supporting substrate 106 is taken and bonded with the previously prepared wafer. This figure is a schematic diagram after the bonding is completed;
  • the preparation substrate 110 is removed by mechanical thinning combined with wet etching or dry etching, and the top electrode 107 is prepared;
  • the seed layer 103 is etched and the bottom electrode is drawn out or interconnected with the next resonator unit by sputtering or electron beam evaporation to realize filter preparation to obtain the novel FBAR filter .
  • FIG. 11 is an effect diagram showing the low insertion loss and wide passband of the filter manufactured in the embodiment.
  • the resonator with high Q value and large effective electromechanical coupling coefficient shows small insertion loss in the performance of the filter formed by cascade, and satisfies the large passband bandwidth.
  • the embodiment of the present invention obtains verify.

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)

Abstract

本发明公开了一种新型FBAR滤波器及其制备方法。该方法包括：在制备衬底上刻蚀出凹槽，在凹槽内制备压电材料和底电极，在制备底电极之前首先制备一薄层种子层，制备空气腔支撑层，另取支撑衬底，将该支撑衬底与制备衬底及空气腔支撑层键合在一起，去除制备衬底，露出压电材料，在压电材料上制备顶电极，将底电极引出，得到由多个谐振器级联而成的滤波器。本发明通过先在制备衬底上挖凹槽再生长压电材料的方法，有效避免生长整层压电薄膜导致应力过大产生裂纹的问题，降低了压电薄膜的应力，同时因每个谐振单元的压电薄膜不连续，有效避免了能量的横向传输造成能量损失的问题，同时还可以有效抑制杂波，提高了滤波器的制备良率和性能。

Description

一种新型FBAR滤波器及其制备方法 技术领域
本发明属于射频滤波技术领域，特别涉及到一种新型FBAR滤波器及其制备方法。
 背景技术
无线通讯终端的多功能化发展对射频器件提出了微型化、高频率、高性能、低功耗、低成本等高技术要求。传统的声表面波滤波器(SAW)在2.4GHz以上的高频段***损耗大，介质滤波器有很好的性能但是体积太大。薄膜体声波谐振器(FBAR)技术是近年来随着加工工艺技术水平的提高和现代无线通信技术，尤其是个人无线通信技术的快速发展而出现的一种新的射频器件技术。它具有极高的品质因数Q值(1000以上)和可集成于IC芯片上的优点，并能与互补金属氧化物半导体(Complementary Metal Oxide Semiconductor，CMOS)工艺兼容，同时有效地避免了声表面波谐振器和介质谐振器无法与CMOS工艺兼容的缺点。
然而空气隙型FBAR滤波器目前受国外专利垄断，该技术路线无法使用，但该结构的FBAR滤波器性能仍有提升空间，如图1所示，它包括衬底、衬底上的空气腔、 衬底上跨越空气腔依次制作底电极、压电层和顶电极。在浙江大学陈炜硕士论文《薄膜体声波谐振器（FBAR）的研究与建模》P47-48中提到国外安捷伦谐振器的制备过程：在Si片的上表面刻蚀空腔，然后在凹坑中填充牺牲层材料PSG，牺牲层表面经CMP抛光后溅射生长一层金属膜，对应在牺牲层上方的位置刻蚀出底电极图形。然后在底电极上方沉积一层压电膜，经刻蚀后，该压电膜盖过衬底上凹坑的边界，并且露出底电极的引出端，接下来在压电膜上沉积一层金属膜，刻蚀出顶电极图形。接下来通过干法刻蚀在压电层上刻蚀出一个释放窗口，将牺牲层部分露出来。最后从刻出的释放窗口将牺牲层释放，衬底上跨过空气腔的FBAR就制作出来了，但这种牺牲层释放的方法会在压电层上留下很多释放通道孔，对压电薄膜损伤很大，导致空腔结构容易塌陷，且Q值和机电耦合系数低，***损耗大，影响器件的性能。
 技术解决方案
为了克服现有技术存在的不足，本发明的目的是提供一种新型FBAR滤波器及其制备方法。本发明提供的新型FBAR滤波器是一种薄膜体声波滤波器。
基于此，本发明的目的在于克服现有技术的缺陷，提出了一种新型FBAR滤波器及其制备方法。采用该制备方法，在制备过程中，无需使用牺牲层，减少了对压电薄膜的破坏，从而克服了在牺牲层去除的过程中对滤波器结构产生不良影响的问题，并且这种在制备衬底上刻蚀凹槽，在槽内制备压电薄膜的方法可以有效降低压电薄膜的应力，抑制杂波，减少能量损失，可以很好的改善压电膜的品质，降低薄膜体声波谐振器的***损耗，提高Q值和机电耦合系数，将成为适用于未来高频、高功率场合下射频滤波器的解决方案。
本发明的目的至少通过如下技术方案之一实现。
本发明提供的新型FBAR滤波器，由n个谐振器级联而成，n为整数且n≥1；所述谐振器包括支撑衬底、空气腔支撑层、底电极、种子层、压电薄膜结构层、顶电极及底电极上引；所述空气腔支撑层有两个，分别层叠在支撑衬底上，底电极分别与这两个空气腔支撑层连接，底电极、空气腔支撑层及支撑衬底围成空腔；所述种子层层叠在底电极和空气腔支撑层上；所述压电薄膜结构层、顶电极依次层叠在种子层上；所述底电极上引与底电极连接。
进一步地，所述支撑衬底为硅衬底、蓝宝石衬底、碳化硅衬底，氮化镓衬底、氮化铝衬底、AlxGa1-xN缓冲层衬底、玻璃衬底、有机高分子材料柔性衬底等中的一种以上。
进一步地，所述空气腔支撑层的材料为绝缘材料，所述绝缘材料为SiO 2、AlN，Si 3N 4中的一种以上；所述空气腔支撑层的厚度为0.3-3μm。
优选地，所述支撑层的材料为绝缘材料；所述支撑层的材料为二氧化硅、氮化硅、氮化铝、氮化镓等介电常数较高的材料。
进一步地，所述底电极和顶电极的材料为Al、Mo、W、Pt、 Cu、Ag、Au、ZrN等中的一种以上；所述底电极和顶电极的厚度均为20-500nm。
进一步地，所述种子层为溅射的多晶压电材料或单晶压电材料；所述种子层的材料为AlN、ZnO、铌酸锂及钽酸锂等中的一种以上；所述种子层的厚度为5-100nm。
进一步地，所述压电薄膜结构层为外延生长的高质量单晶压电薄膜、通过溅射生长的高C轴取向的多晶压电薄膜、具有压电特性的薄膜中的一种以上；所述压电薄膜结构层的材料为AlN、ZnO、PZT、铌酸锂、钽酸锂等中的一种以上；所述压电薄膜结构层的厚度为0.02μm-10μm。
本发明提供的新型FBAR滤波器，其滤波频率为10MHz-100GHz。
本发明提供的新型FBAR滤波器的制备方法，包括：首先在制备衬底上通过刻蚀方法制备出凹槽（凹槽的数量可以是多个），然后在凹槽内制备压电材料，随后制备底电极，在制备底电极之前首先制备一薄层种子层，制备空气腔支撑层，另取一支撑衬底，将该支撑衬底与制备衬底以及上面个的结构键合在一起，随后将制备衬底去除，露出压电材料，在压电材料上方制备顶电极，并将底电极引出，最终制备出由多个基本谐振器级联而成的滤波器。
本发明提供的新型FBAR滤波器的制备方法，包括如下步骤：
（1）在制备衬底上刻蚀n个凹槽（凹槽的数量可以为多个），n为整数且n≥1；，然后在凹槽内制备压电薄膜结构层（压电材料），采用外延或溅射的方法在所述压电薄膜结构层上制备种子层（薄层底电极种子层），接着通过溅射或电子束蒸发法在种子层上制备底电极并图形化；
（2）在底电极和种子层上制备两个空气腔支撑层（沉积绝缘材料并图形化作为空气腔支撑层），另取一个支撑衬底（该衬底可以是硅片、蓝宝石、硅、蓝宝石、 LiGaO2、GaN、SiC、玻璃、有机高分子材料等），将支撑衬底同时与两个空气腔支撑层及制备衬底键合，底电极、空气腔支撑层及支撑衬底围成空腔，完成键合后，将制备衬底去除，去除方法为行业内常用的机械减薄结合湿法刻蚀或干法刻蚀；
（3）制备衬底去除后，压电薄膜结构层裸露，在所述压电薄膜结构层上制备顶电极，并将底电极引出（对种子层进行底电极上引通孔的刻蚀，方法可以是湿法腐蚀或干法刻蚀），底电极上引可以采用电镀或者蒸镀溅射等方法实现，得到所述新型FBAR滤波器（由多个谐振器级联而成的滤波器）。
进一步地，步骤（1）所述制备衬底为硅衬底、蓝宝石衬底、碳化硅衬底，氮化镓衬底、LiGaO 2衬底、氮化铝衬底、AlxGa1-xN缓冲层衬底、玻璃衬底、有机高分子材料柔性衬底中的一种以上。
进一步地，步骤（2）所述支撑衬底与空气腔支撑层键合的一面中间刻有空腔，空腔深度为0.5-3微米。
本发明提供的制备方法，能制备出任意频率的FBAR滤波器，包括从10MHz到10GHz频率范围内的FBAR滤波器。
 有益效果
与现有技术相比，本发明具有如下优点和有益效果：
本发明提供的制备方法，在制备过程中，无需使用牺牲层，减少了对压电薄膜的破坏，从而克服了在牺牲层去除的过程中对滤波器结构产生不良影响的问题，并且这种在制备衬底上刻蚀凹槽，在槽内制备压电薄膜的方法可以有效降低压电薄膜的应力，抑制杂波，减少能量损失，可以很好的改善压电膜的品质，降低薄膜体声波谐振器的***损耗，提高Q值和机电耦合系数，将成为适用于未来高频、高功率场合下射频滤波器的解决方案。
 附图说明
图1为现有技术中空气隙型FBAR剖面图；
图2为实施例中的制备衬底的剖面图；
图3为实施例中在制备衬底上刻蚀出凹槽的示意图；
图4为实施例中在制备衬底凹槽内制备压电薄膜的示意图；
图5为实施例中制备种子层和底电极的示意图；
图6为实施例中沉积一层绝缘介质支撑层并图形化的示意图；
图7为实施例中另取一片支撑衬底并与前面晶圆做键合的示意图；
图8为实施例中制备衬底去除并制备出顶电极的示意图；
图9为实施例中制备底电极上引后得到的新型FBAR滤波器的示意图；
图10为实施例中谐振器梯形级联构造滤波器原理展示图。
图11为实施例中所制造的滤波器所体现出来低***损耗和宽通带的效果图。
 本发明的实施方式
以下结合实例对本发明的具体实施作进一步说明，但本发明的实施和保护不限于此。需指出的是，以下若有未特别详细说明之过程，均是本领域技术人员可参照现有技术实现或理解的。所用试剂或仪器未注明生产厂商者，视为可以通过市售购买得到的常规产品。
实施例1
一种新型FBAR滤波器，由n个谐振器级联而成，n为正整数且n≥1；如图9所示，所述谐振器包括支撑衬底106、空气腔支撑层105、底电极104、种子层103、压电薄膜结构层102、顶电极107及底电极上引108；所述空气腔支撑层105有两个，分别层叠在支撑衬底106上，底电极104分别与这两个空气腔支撑层105连接，底电极104、空气腔支撑层105及支撑衬底106围成空腔；所述种子层层叠在底电极104和空气腔支撑层105上；所述压电薄膜结构层102、顶电极107依次层叠在种子层103上；所述底电极上引108与底电极104连接。
所述支撑衬底106为硅衬底、蓝宝石衬底、碳化硅衬底，氮化镓衬底、氮化铝衬底、AlxGa1-xN缓冲层衬底、玻璃衬底、有机高分子材料柔性衬底中的一种以上。
所述空气腔支撑层105的材料为绝缘材料，所述绝缘材料为SiO 2、AlN，Si 3N 4中的一种以上；所述空气腔支撑层105的厚度为0.3-3μm。
所述底电极104和顶电极107的材料为Al、Mo、W、Pt、 Cu、Ag、Au、ZrN中的一种以上；所述底电极104和顶电极107的厚度均为20-500nm。
所述种子层103为溅射的多晶压电材料或单晶压电材料；所述种子层103的材料为AlN、ZnO、铌酸锂及钽酸锂中的一种以上；所述种子层103的厚度为5-100nm。
所述压电薄膜结构层102为外延生长的单晶压电薄膜、通过溅射生长的高C轴取向的多晶压电薄膜、具有压电特性的薄膜中的一种以上；所述压电薄膜结构层102的材料为AlN、ZnO、PZT、铌酸锂、钽酸锂中的一种以上；所述压电薄膜结构层102的厚度为0.02μm-10μm。
通过不同压电层厚度以及不同电极厚度的组合，谐振器谐振频率频率可从10MHz到10GHz，进而可以通过级联形成滤波器通带从10MHz到10GHz。图10为实施例中谐振器梯形级联构造滤波器原理展示图。如图10所示，串联谐振器和并联谐振器梯形级联，构成最基本的滤波器单元，通过谐振频率的相对应，形成通带；如此一来，谐振器的频率是受压电层厚度和电极厚度影响（如下表1所示），可形成不一样频率通带的滤波器。表1为实施例中不同压电层厚度和电极厚度组合形成不同谐振点的数据表。
表1
Figure dest_path_image001
实施例2
一种新型FBAR滤波器的制备方法，具体制备方法如下：
（1）如图2所示，取一制备衬底110，制备衬底110可以为硅、碳化硅、蓝宝石、玻璃、金属或有机高分子的衬底材料；
（2）如图3所示，在制备衬底110上通过刻蚀方法刻蚀出凹槽101；
（3）如图4所示，在101凹槽内通过化学气相沉积或溅射方法制备压电薄膜结构层102，压电薄膜结构层102为单晶或多晶氮化铝材料，也可以是ZnO、PZT这些具有压电特性的材料，压电薄膜结构层102厚度在0.02到10微米之间。
（4）如图5所示，在压电薄膜结构层102上通过化学气相沉积或溅射或电子束蒸发方法制备种子层103和底电极104，并进行图形化处理，得到需要的电极图形，电极材料可以为Al、Mo、W、Pt、 Cu、Ag、Au、ZrN中的一种以上，电极材料也可以是其他导电性能良好的材料，比如石墨烯等非金属材料，电极厚度在0.1纳米到500纳米范围内。
（5）如图6所示，接着沉积空气腔支撑层（绝缘层）105，厚度在0.2-4微米范围内，然后通过机械抛光抛平和图形化刻蚀，得到图6所示的空气腔支撑层105；
（5）如图7所示，另取一片支撑衬底106，与前面所准备的晶圆进行键合，此图为键合完成后示意图；
（6）如图8所示，通过机械减薄结合湿法腐蚀或干法刻蚀等方法去除所述制备衬底110，并制备顶电极107；
（7）如图9所示，对种子层103进行刻蚀并通过溅射或电子束蒸发的方式将底电极引出或与下一个谐振器单元互联实现滤波器制备，得到所述新型FBAR滤波器。
图11为实施例中所制造的滤波器所体现出来低***损耗和宽通带的效果图。如图11所示，高Q值和较大的有效机电耦合系数的谐振器，在级联构成的滤波器性能上，体现出***损耗小，满足较大的通带带宽，本发明实施例得到验证。
以上所述具体实施方式仅表达了本发明的一种实施方式，可以用于制备不同频率范围的FBAR滤波器，其描述在此较为简略，但并不能因此而为对本发明专利范围的限制。应当指出的是，对于本领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干变形和改进，这些都属于本发明的保护范围。因此，本发明的保护范围应以所附权利要求为准。

Claims (10)

  1. 一种新型FBAR滤波器，其特征在于，由n个谐振器级联而成，n为整数且n≥1；所述谐振器包括支撑衬底、空气腔支撑层、底电极、种子层、压电薄膜结构层、顶电极及底电极上引；所述空气腔支撑层有两个，分别层叠在支撑衬底上，底电极分别与这两个空气腔支撑层连接，底电极、空气腔支撑层及支撑衬底围成空腔；所述种子层层叠在底电极和空气腔支撑层上；所述压电薄膜结构层、顶电极依次层叠在种子层上；所述底电极上引与底电极连接。
  2. 根据权利要求1所述的新型FBAR滤波器，其特征在于，所述支撑衬底为硅衬底、蓝宝石衬底、碳化硅衬底，氮化镓衬底、氮化铝衬底、AlxGa1-xN缓冲层衬底、玻璃衬底、有机高分子材料柔性衬底中的一种以上。
  3. 根据权利要求1所述的新型FBAR滤波器，其特征在于，所述空气腔支撑层的材料为绝缘材料，所述绝缘材料为SiO 2、AlN，Si 3N 4中的一种以上；所述空气腔支撑层的厚度为0.3-3μm。
  4. 根据权利要求1所述的新型FBAR滤波器，其特征在于，所述底电极和顶电极的材料均为Al、Mo、W、Pt、 Cu、Ag、Au、ZrN中的一种以上；所述底电极和顶电极的厚度均为20-500nm。
  5. 根据权利要求1所述的新型FBAR滤波器，其特征在于，所述种子层为溅射的多晶压电材料或单晶压电材料；所述种子层的材料为AlN、ZnO、铌酸锂及钽酸锂中的一种以上；所述种子层的厚度为5-100nm。
  6. 根据权利要求1所述的新型FBAR滤波器，其特征在于，所述压电薄膜结构层为外延生长的单晶压电薄膜、通过溅射生长的高C轴取向的多晶压电薄膜、具有压电特性的薄膜中的一种以上；所述压电薄膜结构层的材料为AlN、ZnO、PZT、铌酸锂、钽酸锂中的一种以上；所述压电薄膜结构层的厚度为0.02μm-10μm。
  7. 根据权利要求1所述的新型FBAR滤波器，其特征在于，滤波的频率为10MHz-100GHz。
  8. 一种制备权利要求1-7任一项所述的新型FBAR滤波器的方法，其特征在于，包括如下步骤：
    （1）在制备衬底上刻蚀n个凹槽，n为整数且n≥1，然后分别在每个凹槽内制备压电薄膜结构层，在所述压电薄膜结构层上制备种子层，接着在种子层上制备底电极；
    （2）在底电极和种子层上制备两个空气腔支撑层，另取一个支撑衬底，将支撑衬底同时与两个空气腔支撑层键合，底电极、空气腔支撑层及支撑衬底围成空腔；
    （3）将制备衬底去除，使压电薄膜结构层裸露，在所述压电薄膜结构层上制备顶电极，并将底电极引出，得到所述新型FBAR滤波器。
  9. 根据权利要求8所述的新型FBAR滤波器的制备方法，其特征在于，步骤（1）所述制备衬底为硅衬底、蓝宝石衬底、碳化硅衬底，氮化镓衬底、氮化铝衬底、AlxGa1-xN缓冲层衬底、玻璃衬底、有机高分子材料柔性衬底中的一种以上。
  10. 根据权利要求8所述的新型FBAR滤波器的制备方法，其特征在于，步骤（2）所述支撑衬底与空气腔支撑层键合的一面中间刻有空腔，空腔深度为0.5-3微米。
     
     
PCT/CN2021/127793 2020-12-24 2021-10-31 一种新型fbar滤波器及其制备方法 WO2022134860A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202011572935.9A CN112671367A (zh) 2020-12-24 2020-12-24 一种新型fbar滤波器及其制备方法
CN202011572935.9 2020-12-24

Publications (1)

Publication Number Publication Date
WO2022134860A1 true WO2022134860A1 (zh) 2022-06-30

Family

ID=75410169

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2021/127793 WO2022134860A1 (zh) 2020-12-24 2021-10-31 一种新型fbar滤波器及其制备方法

Country Status (2)

Country Link
CN (1) CN112671367A (zh)
WO (1) WO2022134860A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117579026A (zh) * 2023-12-06 2024-02-20 武汉敏声新技术有限公司 一种薄膜体声波谐振器及其制备方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112671367A (zh) * 2020-12-24 2021-04-16 华南理工大学 一种新型fbar滤波器及其制备方法
CN115051673A (zh) * 2021-03-08 2022-09-13 诺思(天津)微***有限责任公司 体声波谐振器及其制造方法、滤波器及电子设备
CN117294277B (zh) * 2023-11-24 2024-03-26 广州市艾佛光通科技有限公司 一种高功率高机电耦合系数的体声波谐振器及其制备方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103916100A (zh) * 2013-01-02 2014-07-09 财团法人工业技术研究院 微机电共振装置
CN107947750A (zh) * 2017-11-22 2018-04-20 周燕红 一种压电谐振器的制备方法及压电谐振器
CN109309483A (zh) * 2018-10-10 2019-02-05 华南理工大学 一种支撑型薄膜体声波谐振器的制备方法
CN110474616A (zh) * 2019-08-29 2019-11-19 华南理工大学 一种空气隙型薄膜体声波谐振器及其制备方法
WO2020040376A1 (en) * 2018-08-24 2020-02-27 Btbl Co., Ltd Method of manufacturing ultrasonic sensors
CN112671367A (zh) * 2020-12-24 2021-04-16 华南理工大学 一种新型fbar滤波器及其制备方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103916100A (zh) * 2013-01-02 2014-07-09 财团法人工业技术研究院 微机电共振装置
CN107947750A (zh) * 2017-11-22 2018-04-20 周燕红 一种压电谐振器的制备方法及压电谐振器
WO2020040376A1 (en) * 2018-08-24 2020-02-27 Btbl Co., Ltd Method of manufacturing ultrasonic sensors
CN109309483A (zh) * 2018-10-10 2019-02-05 华南理工大学 一种支撑型薄膜体声波谐振器的制备方法
CN110474616A (zh) * 2019-08-29 2019-11-19 华南理工大学 一种空气隙型薄膜体声波谐振器及其制备方法
CN112671367A (zh) * 2020-12-24 2021-04-16 华南理工大学 一种新型fbar滤波器及其制备方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117579026A (zh) * 2023-12-06 2024-02-20 武汉敏声新技术有限公司 一种薄膜体声波谐振器及其制备方法

Also Published As

Publication number Publication date
CN112671367A (zh) 2021-04-16

Similar Documents

Publication Publication Date Title
WO2022134860A1 (zh) 一种新型fbar滤波器及其制备方法
CN109309483B (zh) 一种支撑型薄膜体声波谐振器的制备方法
CN107809221B (zh) 一种空腔型薄膜体声波谐振器及其制备方法
CN107093994B (zh) 薄膜体声波谐振器及其加工方法
WO2022116396A1 (zh) 一种无源空腔型单晶薄膜体声波谐振器结构及制备方法
CN111446944B (zh) 一种利于集成的空气隙型薄膜体声波谐振器及其制备方法
CN105703733A (zh) 一种固态装配型薄膜体声波谐振器的制备方法
CN109302158B (zh) 一种薄膜体声波谐振器及其制备方法
WO2020056835A1 (zh) 柔性单晶兰姆波谐振器及其形成方法
WO2021012916A1 (zh) 一种薄膜体声波谐振器及其制造方法
JP2006186412A (ja) 薄膜圧電共振器およびその製造方法
CN110784188B (zh) 谐振器及其制备方法
CN109302159B (zh) 一种复合衬底及该复合衬底制作薄膜体声波谐振器的方法
CN210444236U (zh) Fbar滤波器
CN112039481B (zh) 体声波谐振器及其制造方法
WO2024087399A1 (zh) 一种体声波滤波器及其制作方法
WO2024012311A1 (zh) 声表面波谐振装置的形成方法
CN111654258B (zh) 薄膜体声波谐振器制作方法、薄膜体声波谐振器及滤波器
CN111446943A (zh) 一种利用射频电感优化单晶薄膜体声波谐振器滤波器及其制备方法
WO2023125757A1 (zh) 一种高带宽空腔型薄膜体声波谐振器及其制备方法
CN112134540A (zh) 一种复合电极的体声波谐振器及其制备方法
CN113285014A (zh) 单晶掺杂薄膜、声波谐振器用压电薄膜及其制备方法
CN113193846A (zh) 一种带混合横向结构特征的薄膜体声波谐振器
JP2002372974A (ja) 薄膜音響共振器及びその製造方法
CN212381185U (zh) 一种利于集成的空气隙型薄膜体声波谐振器

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: 21908861

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21908861

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 21908861

Country of ref document: EP

Kind code of ref document: A1