CN119154833B - Solid-state assembly type bulk acoustic wave resonator and preparation method thereof - Google Patents
Solid-state assembly type bulk acoustic wave resonator and preparation method thereof Download PDFInfo
- Publication number
- CN119154833B CN119154833B CN202411274491.9A CN202411274491A CN119154833B CN 119154833 B CN119154833 B CN 119154833B CN 202411274491 A CN202411274491 A CN 202411274491A CN 119154833 B CN119154833 B CN 119154833B
- Authority
- CN
- China
- Prior art keywords
- conductive
- acoustic impedance
- layer
- impedance layer
- reflection structure
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic elements; 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
- H03H9/171—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator implemented with thin-film techniques, i.e. of the film bulk acoustic resonator [FBAR] type
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
- H03H9/02—Details
- H03H9/02007—Details of bulk acoustic wave devices
- H03H9/02086—Means for compensation or elimination of undesirable effects
- H03H9/0211—Means for compensation or elimination of undesirable effects of reflections
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
- H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
- H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
- H03H2003/023—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks the resonators or networks being of the membrane type
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
本申请公开了一种固态装配型体声波谐振器及其制备方法，其中，固态装配型体声波谐振器包括衬底、依次层叠于衬底上的布拉格反射结构、第一电极层、压电层和第二电极层，布拉格反射结构包括非导电反射结构和导电反射结构，非导电反射结构和导电反射结构均包括交替堆叠的高声阻抗层和低声阻抗层，非导电反射结构的高声阻抗层和低声阻抗层的材料均为非导电材料，导电反射结构的高声阻抗层和低声阻抗层中的至少一层的材料为导电材料。本申请通过在衬底和第一电极层之间设置非导电反射结构，可以有效阻止声波透过布拉格反射结构传输至衬底，由于非导电反射结构均为非导电材料，无需对其进行图案化处理，可以减少刻蚀次数，降低工艺难度。
The present application discloses a solid-state assembly type bulk acoustic wave resonator and a preparation method thereof, wherein the solid-state assembly type bulk acoustic wave resonator comprises a substrate, a Bragg reflection structure stacked on the substrate in sequence, a first electrode layer, a piezoelectric layer, and a second electrode layer, the Bragg reflection structure comprises a non-conductive reflection structure and a conductive reflection structure, the non-conductive reflection structure and the conductive reflection structure both comprise a high acoustic impedance layer and a low acoustic impedance layer stacked alternately, the material of the high acoustic impedance layer and the low acoustic impedance layer of the non-conductive reflection structure are both non-conductive materials, and the material of at least one of the high acoustic impedance layer and the low acoustic impedance layer of the conductive reflection structure is a conductive material. The present application can effectively prevent sound waves from being transmitted to the substrate through the Bragg reflection structure by arranging a non-conductive reflection structure between the substrate and the first electrode layer. Since the non-conductive reflection structure is made of non-conductive materials, it is not necessary to perform patterning on it, which can reduce the number of etching times and the process difficulty.
Description
Technical Field
The invention relates to the technical field of resonators, in particular to a solid-state assembly type bulk acoustic wave resonator and a preparation method thereof.
Background
The BAW resonator (Bulk Acoustic Wave Resonator, BAW) is a resonant device based on bulk acoustic wave propagation, has the advantages of high quality factor, high frequency stability, low loss and the like, and is widely applied to the fields of wireless communication, digital televisions, computers, bulk acoustic wave filters and the like. The BAW resonator has the working principle that the piezoelectric effect of piezoelectric materials is utilized to convert electric energy into mechanical energy, generate bulk acoustic waves and form resonance in a resonant cavity, so that the selection and the control of frequency are realized.
The bulk acoustic wave resonators of the main stream are two types, one is a thin film bulk acoustic wave resonator (Film Bulk Acoustic Resonator, FBAR) and the other is a solid state mounted bulk acoustic wave resonator (Solidly Mounted Resonator, SMR). Wherein, the FBAR is composed of upper and lower electrodes and a piezoelectric film sandwiched therebetween. The resonant cavity of the FBAR is formed by an air gap or a vacuum gap below the piezoelectric film, the structure can effectively reduce the propagation loss of sound waves, but the preparation process is complex, the yield is low, the contact surface of the FBAR device and the substrate is small, the generated heat accumulation effect is serious, and the structure is difficult to be suitable for some high-power application scenes. The primary difference between SMR and FBAR is the manner in which the resonator is formed. SMR uses a high acoustic impedance thin film material (e.g., tungsten) alternating with a low acoustic impedance thin film material (e.g., silicon dioxide) to form a bragg acoustic reflection structure instead of an air gap or vacuum gap in the FBAR. The SMR adopts a bragg reflection structure to replace an air gap or a vacuum gap in the FBAR, and the structure can better resist the influence of external environment, such as temperature change, mechanical stress and the like, so that the stability and the reliability of the resonator are improved. SMRs are generally capable of withstanding higher power, which makes them advantageous over FBARs in some applications where high power signals need to be processed.
The performance of an SMR, particularly the resonator Quality Factor (Q), is closely related to the structural design of its bragg acoustic reflection layer. To optimize the acoustic reflection layer of the SMR, careful selection of high acoustic impedance and low acoustic impedance materials is required. High acoustic impedance materials typically have a relatively high density and modulus of elasticity, such as tungsten, titanium tungsten alloy, molybdenum, aluminum nitride, etc., while low acoustic impedance materials typically have a relatively low density and modulus of elasticity, such as silicon dioxide, silicon nitride, styrene-acrylic, etc. In addition, the optimal reflecting layer number is determined through theoretical calculation and simulation. Generally, increasing the number of layers increases the reflection efficiency, but also increases the manufacturing difficulty and cost.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a solid-state assembled bulk acoustic wave resonator and a method of manufacturing the same.
According to a first aspect of the present invention, there is provided a bulk acoustic wave resonator comprising a substrate, a bragg reflection structure laminated on the substrate in that order, a first electrode layer, a piezoelectric layer and a second electrode layer:
The Bragg reflection structure comprises a non-conductive reflection structure and a conductive reflection structure, wherein the non-conductive reflection structure and the conductive reflection structure comprise high acoustic impedance layers and low acoustic impedance layers which are alternately stacked, the materials of the high acoustic impedance layers and the low acoustic impedance layers of the non-conductive reflection structure are non-conductive materials, and the material of at least one layer of the high acoustic impedance layers and the low acoustic impedance layers of the conductive reflection structure is a conductive material.
Optionally, the non-conductive reflective structure is located on and completely covers the substrate, the non-conductive reflective structure being a first periodic structure, each first period including a first high acoustic impedance layer and a first low acoustic impedance layer, the first period number being at least 1.
Optionally, the conductive reflective structure is located between the non-conductive reflective structure and the first electrode layer and partially covers the non-conductive reflective structure, the conductive reflective structure is a second periodic structure, each second period includes a second high acoustic impedance layer and a second low acoustic impedance layer, and the second period number is at least 1.
Optionally, the number of cycles of the bragg reflection structure is at least 3.
Optionally, the material of the first high acoustic impedance layer is at least one of aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, and tungsten oxide, and the material of the first low acoustic impedance layer is at least one of silicon dioxide, silicon nitride, magnesium oxide, a nano porous mixture, aerogel, xerogel, or a polymer material.
Optionally, the material of the second high acoustic impedance layer is at least one of tungsten, titanium tungsten, molybdenum, platinum, ruthenium, iridium, hafnium, tantalum, nickel, chromium, cobalt, zirconium carbide, cobalt oxide, aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, and tungsten oxide, and the material of the second low acoustic impedance layer is at least one of aluminum, magnesium, silicon dioxide, silicon nitride, magnesium oxide, a nano-porous mixture, aerogel, xerogel, or a polymer material.
Optionally, when the second high acoustic impedance layer and the second low acoustic impedance layer are both conductive materials, the second high acoustic impedance layer and the second low acoustic impedance layer partially cover the non-conductive reflective structure, when the second high acoustic impedance layer is made of conductive materials and the second low acoustic impedance layer is made of non-conductive materials, the second low acoustic impedance layer completely covers the non-conductive reflective structure, and when the second high acoustic impedance layer is made of non-conductive materials, the second high acoustic impedance layer completely covers the non-conductive reflective structure, and when the second low acoustic impedance layer is made of conductive materials, the second high acoustic impedance layer completely covers the non-conductive reflective structure.
According to a second aspect of the invention, the preparation method of the solid-state assembly type bulk acoustic wave resonator comprises the steps of forming a Bragg reflection structure on a substrate, sequentially forming a first electrode layer, a piezoelectric layer and a second electrode layer on the Bragg reflection structure, forming the Bragg reflection structure on the substrate, wherein the Bragg reflection structure comprises the steps of alternately depositing a high acoustic impedance layer and a low acoustic impedance layer on the substrate to form a non-conductive reflection structure, alternately depositing a high acoustic impedance layer and a low acoustic impedance layer on the non-conductive reflection structure, and patterning the non-conductive reflection structure to form a conductive reflection structure, wherein the materials of the high acoustic impedance layer and the low acoustic impedance layer of the non-conductive reflection structure are non-conductive materials, and the materials of at least one layer of the high acoustic impedance layer and the low acoustic impedance layer of the conductive reflection structure are conductive materials.
Optionally, the high acoustic impedance layer and the low acoustic impedance layer of the conductive reflective structure are each patterned to form a conductive reflective structure, wherein the conductive reflective structure partially covers the non-conductive reflective structure.
Optionally, one layer of the conductive reflective structure is patterned and the other layer is not patterned to form a conductive reflective structure, wherein one layer partially covers the non-conductive reflective structure and the other layer completely covers the non-conductive reflective structure;
wherein, the material of one layer is conductive material, and the material of the other layer is non-conductive material.
Advantageous effects
According to the solid-state assembly type bulk acoustic wave resonator and the preparation method thereof, the Bragg reflection structure of the bulk acoustic wave resonator comprises the non-conductive reflection structure and the conductive reflection structure, the non-conductive reflection structure is arranged between the substrate and the first electrode layer, so that the acoustic wave transmission coefficient is not damaged, the acoustic wave can be still effectively prevented from being transmitted to the substrate through the Bragg reflection structure, and the non-conductive reflection structure is made of non-conductive materials, so that patterning treatment is not needed, the metal etching times can be reduced, and the process preparation difficulty of the Bragg reflection structure is reduced.
Further, under the condition that the cycle number of the Bragg reflection structure is fixed, the number of layers of the non-conductive reflection structure is increased, the number of layers of the corresponding conductive reflection structure is smaller, steps generated by metal etching are smaller, the process preparation difficulty is further reduced, and the product yield is improved.
Drawings
The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:
FIGS. 1a and 1b are schematic views showing structures of solid state assembled bulk acoustic wave resonators in the prior art, respectively;
FIG. 2 shows a schematic diagram of the transmission coefficients of the Bragg reflection layers in the solid state assembled bulk acoustic wave resonator shown in FIGS. 1a and 1 b;
fig. 3 is a schematic view showing the structure of a solid-state assembled bulk acoustic wave resonator according to a first embodiment of the present invention;
Fig. 4 is a schematic diagram showing the structure of a solid-state assembled bulk acoustic wave resonator according to a second embodiment of the present invention;
Fig. 5 is a schematic diagram showing the structure of a solid-state assembled bulk acoustic wave resonator according to a third embodiment of the present invention;
FIG. 6 is a schematic diagram showing the transmission coefficients of Bragg reflection layers in a solid state assembled bulk acoustic wave resonator according to a third embodiment of the present invention;
FIGS. 7 a-7 l are schematic diagrams showing various stages of a method of manufacturing a solid state assembled bulk acoustic wave resonator according to an embodiment of the present invention;
Fig. 8a to 8l are schematic views showing different stages of a method for manufacturing a solid-state assembled bulk acoustic wave resonator according to another embodiment of the present invention.
Detailed Description
Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. The same reference numbers will be used throughout the drawings to refer to the same or like parts. For clarity, the various features of the drawings are not drawn to scale.
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples.
The prior art solid state ligand bulk acoustic wave resonator 100 includes a substrate 110, a bragg reflection structure 120, a first electrode layer 130, a piezoelectric layer 140, and a second electrode layer 150. The bragg reflection structure is composed of high acoustic impedance layers 121 and low acoustic impedance layers 122 alternately stacked (see fig. 1a and 1 b). The performance of bulk acoustic wave resonators, in particular the resonator Quality Factor (Q), is closely related to the structural design of their bragg acoustic wave reflecting layers, requiring on the one hand the selection of suitable materials for the high acoustic impedance layer 121 and the low acoustic impedance layer 122, and on the other hand the determination of a suitable number of layers. The material of the high acoustic impedance layer 121 typically has a relatively high density and elastic modulus, such as tungsten, molybdenum, etc., and the material of the low acoustic impedance layer 122 typically has a relatively low density and elastic modulus, such as silicon dioxide, silicon nitride, etc. Furthermore, the number of bragg reflection layers was determined by theoretical calculation and simulation. Generally, increasing the number of layers increases the reflection efficiency, but increases the manufacturing difficulty and cost.
The bragg reflection structure of fig. 1b has a layer of high acoustic impedance added to the bragg reflection structure of fig. 1 a. Referring to fig. 2, the dashed line represents the acoustic wave transmission coefficient of the bragg acoustic wave reflection structure in fig. 1a, the solid line represents the acoustic wave transmission coefficient of the bragg acoustic wave reflection structure in fig. 1b, the maximum reflection frequency of the bragg reflection structure 120 in fig. 1a and 1b is about 2.3GHz, and the limiting capability of the bragg reflection structure in fig. 1b on the acoustic wave is improved compared with that of the bragg reflection structure in fig. 1 a.
The bragg reflective structure of fig. 1b comprises three layers of metal, and requires three photolithography and etching processes, each of which is aligned with the pattern formed by the preceding photolithography. In addition, metal etching can form steps at the edge of the resonator, and the height of the steps formed by the accumulation of multiple layers of metal becomes large. Both of these factors increase the complexity of the process, the device performance is greatly affected by the process accuracy, and the product yield is low.
In order to solve the above problems, the present application provides a solid-state assembled bulk acoustic wave resonator, in which the bragg reflection structure includes a non-conductive reflection structure and a conductive reflection structure, and by disposing the non-conductive reflection structure between the substrate and the first electrode layer, the transmission coefficient of the acoustic wave can be not damaged, and the acoustic wave can be still effectively prevented from being transmitted to the substrate through the bragg reflection structure, and since the materials of the non-conductive reflection structure are non-conductive materials, patterning processing is not required, so that the number of times of metal etching can be reduced, and the process preparation difficulty of the bragg reflection structure can be reduced.
Fig. 3 shows a schematic structure of a solid-state assembled bulk acoustic wave resonator according to a first embodiment of the present invention. As shown in fig. 3, the solid state assembled bulk acoustic wave resonator 200 includes a substrate 210, a bragg reflection structure 220, a first electrode layer 230, a piezoelectric layer 240, and a second electrode layer 250.
Wherein the bragg reflector structure 220 comprises a non-conductive reflector structure 221 and a conductive reflector structure 222.
The non-conductive reflective structure 221 and the conductive reflective structure 222 each include alternately stacked high acoustic impedance layers and low acoustic impedance layers. The material of the high acoustic impedance layer and the low acoustic impedance layer of the non-conductive reflective structure 221 is a non-conductive material, and the material of at least one of the high acoustic impedance layer and the low acoustic impedance layer of the conductive reflective structure 222 is a conductive material. The conductive material is, for example, a metal material and/or an alloy material, but is not limited thereto.
In some embodiments, a high acoustic impedance layer and a low acoustic impedance layer are sequentially deposited on the substrate 210 to form the Bragg reflection structure 220, or a low acoustic impedance layer and a high acoustic impedance layer are sequentially deposited on the substrate to form the Bragg reflection structure 220.
The non-conductive reflective structure 221 is located on the substrate 210 and completely covers the substrate 210, and the conductive reflective structure 222 is located between the non-conductive reflective structure 221 and the first electrode layer 230 and partially covers the non-conductive reflective structure 221.
The non-conductive reflective structure 221 includes first high acoustic impedance layers 2211 and first low acoustic impedance layers 2212 that are alternately stacked, wherein the materials of the first high acoustic impedance layers 2211 and the first low acoustic impedance layers 2212 are non-conductive materials. The non-conductive reflective structure 221 is a first periodic structure having a first period number of at least 1.
Alternatively, the material of the first high acoustic impedance layer 2211 is at least one of aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, and tungsten oxide, for example, but not limited thereto.
Alternatively, the material of the first low acoustic impedance layer 2212 is at least one of silicon dioxide, silicon nitride, magnesium oxide, a nanoporous mixture (e.g., nanoporous methyl silsesquioxane), aerogel, xerogel, or a polymer material (e.g., styrene-butylene), but is not limited thereto.
The conductive reflective structure 222 includes a second high acoustic impedance layer 2221 and a second low acoustic impedance layer 2222 that are alternately stacked, wherein the materials of the second high acoustic impedance layer 2221 and the second low acoustic impedance layer 2222 are both non-conductive materials. The conductive reflective structure 222 is a second periodic structure having a second period number of at least 1.
Optionally, the material of the second high acoustic impedance layer 2221 is at least one of tungsten, titanium tungsten, molybdenum, platinum, ruthenium, iridium, hafnium, tantalum, nickel, chromium, cobalt, zirconium carbide, cobalt oxide, aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, and tungsten oxide, but not limited thereto.
Optionally, the material of the second low acoustic impedance layer 2222 is at least one of aluminum, magnesium, silicon dioxide, silicon nitride, magnesium oxide, a nanoporous mixture (e.g., nanoporous methyl silsesquioxane), an aerogel, a xerogel, or a polymer material (e.g., styrene-acrylate), but is not limited thereto.
In some implementations, the second high acoustic impedance layer 2221 and the second low acoustic impedance layer 2222 are both conductive materials, and the second high acoustic impedance layer 2221 and the second low acoustic impedance layer 2222 are each patterned to partially cover the non-conductive reflective structure 221.
In some implementations, the second high acoustic impedance layer 2221 is a conductive material and the second low acoustic impedance layer 2222 is a non-conductive material, the second low acoustic impedance layer 2222 completely covers the non-conductive reflective structure 221, and the second high acoustic impedance layer 2221 is patterned to partially cover the non-conductive reflective structure 221.
In some implementations, the second high acoustic impedance layer 2221 is a non-conductive material and the second low acoustic impedance layer 2222 is a conductive material, the second high acoustic impedance layer 2221 completely covers the non-conductive reflective structure 221, and the second low acoustic impedance layer 2222 is patterned to partially cover the non-conductive reflective structure 221.
Since the non-conductive reflective structure 221 and the conductive reflective structure 222 are both periodic structures, the bragg reflective structure 220 is also a periodic structure, and the period of the bragg reflective structure 220 is at least 3.
The Bragg reflection structure of the solid-state assembly type bulk acoustic wave resonator provided by the application comprises the non-conductive reflection structure and the conductive reflection structure, and the non-conductive reflection structure is arranged between the substrate and the first electrode layer, so that the acoustic wave transmission coefficient is not damaged, the acoustic wave can still be effectively prevented from being transmitted to the substrate through the Bragg reflection structure, and the non-conductive reflection structure is made of non-conductive materials, so that patterning treatment is not required, the metal etching times can be reduced, and the process preparation difficulty of the Bragg reflection structure is reduced.
Further, under the condition that the cycle number of the Bragg reflection structure is fixed, the number of layers of the non-conductive reflection structure is increased, the number of layers of the corresponding conductive reflection structure is smaller, steps generated by metal etching are smaller, the process preparation difficulty is further reduced, and the product yield is improved.
Fig. 4 shows a schematic structure of a solid-state assembled bulk acoustic wave resonator according to a second embodiment of the present invention. As shown in fig. 4, the bulk acoustic wave resonator 300 includes a substrate 310, a bragg reflection structure 320, a first electrode layer 330, a piezoelectric layer 340, and a second electrode layer 350.
Wherein the bragg reflector structure 320 comprises a non-conductive reflector structure 321 and a conductive reflector structure 322.
The non-conductive reflective structure 321 and the conductive reflective structure 322 each include alternately stacked layers of high acoustic impedance and layers of low acoustic impedance. The material of the high acoustic impedance layer and the low acoustic impedance layer of the non-conductive reflective structure 321 is a non-conductive material, and the material of at least one of the high acoustic impedance layer and the low acoustic impedance layer of the conductive reflective structure 322 is a conductive material. The conductive material is, for example, a metal material and/or an alloy material, but is not limited thereto.
In some embodiments, a high acoustic impedance layer and a low acoustic impedance layer are sequentially deposited on the substrate 310 to form the Bragg reflection structure 320, or a low acoustic impedance layer and a high acoustic impedance layer are sequentially deposited on the substrate to form the Bragg reflection structure 320.
The non-conductive reflective structure 321 is located on the substrate 310 and completely covers the substrate 310, and the conductive reflective structure 322 is located between the non-conductive reflective structure 321 and the first electrode layer 330 and partially covers the non-conductive reflective structure 321.
The non-conductive reflective structure 321 includes first high acoustic impedance layers 3211 and first low acoustic impedance layers 3212 that are alternately stacked, wherein the materials of the first high acoustic impedance layers 3211 and the first low acoustic impedance layers 3212 are non-conductive materials. The non-conductive reflective structure 321 is a first periodic structure, and the first period number is at least 1.
Alternatively, the material of the first high acoustic impedance layer 3211 is at least one of aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, and tungsten oxide, for example, but not limited thereto.
Alternatively, the material of the first low acoustic impedance layer 3212 is at least one of silicon dioxide, silicon nitride, magnesium oxide, a nanoporous mixture (e.g., nanoporous methyl silsesquioxane), aerogel, xerogel, or a polymer material (e.g., styrene-butylene), but is not limited thereto.
The conductive reflective structure 322 includes second high acoustic impedance layers 3221 and second low acoustic impedance layers 3222 alternately stacked, wherein the materials of the second high acoustic impedance layers 3221 and the second low acoustic impedance layers 3222 are non-conductive materials. The conductive reflective structure 322 is a second periodic structure having a second number of periods of at least 1.
Optionally, the material of the second high acoustic impedance layer 3221 is at least one of tungsten, titanium tungsten, molybdenum, platinum, ruthenium, iridium, hafnium, tantalum, nickel, chromium, cobalt, zirconium carbide, cobalt oxide, aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, and tungsten oxide, but not limited thereto.
Optionally, the material of the second low acoustic impedance layer 3222 is at least one of aluminum, magnesium, silicon dioxide, silicon nitride, magnesium oxide, a nanoporous mixture (e.g., nanoporous methyl silsesquioxane), aerogel, xerogel, or a polymer material (e.g., styrene-acrylate), but is not limited thereto.
In some implementations, both the second high acoustic impedance layer 3221 and the second low acoustic impedance layer 3222 are conductive materials, and both the second high acoustic impedance layer 3221 and the second low acoustic impedance layer 3222 are patterned to partially cover the non-conductive reflective structure 321.
In some implementations, the second high acoustic impedance layer 3221 is a conductive material and the second low acoustic impedance layer 3222 is a non-conductive material, the second low acoustic impedance layer 3222 completely covers the non-conductive reflective structure 321, the second high acoustic impedance layer 3221 being patterned to partially cover the non-conductive reflective structure 321.
In some implementations, the second high acoustic impedance layer 3221 is a non-conductive material and the second low acoustic impedance layer 3222 is a conductive material, the second high acoustic impedance layer 3221 completely covers the non-conductive reflective structure 321, the second low acoustic impedance layer 3222 being patterned to partially cover the non-conductive reflective structure 321.
Since the non-conductive reflective structure 321 and the conductive reflective structure 322 are both periodic structures, the bragg reflective structure 320 is also a periodic structure, and the number of cycles of the bragg reflective structure 320 is at least 3.
Compared with the first embodiment, the number of periods of the non-conductive reflective structure in this embodiment is 1, and the number of periods of the conductive reflective structure is 2.
Fig. 5 shows a schematic structural diagram of a solid-state assembled bulk acoustic wave resonator according to a third embodiment of the present application. Compared with the first embodiment, the non-conductive reflecting structure in the application has the cycle number of 2, and the conductive reflecting structure has the cycle number of 2. The other components are the same as those of the first embodiment, and will not be described again.
Fig. 6 shows the transmission coefficient of the bragg reflection structure of the third embodiment of the present invention. Compared with the solid-state assembly type bulk acoustic wave resonator structure shown in fig. 1b, the acoustic wave transmission coefficient of the hybrid bragg acoustic wave reflecting structure is not reduced in the same frequency range, but the process is simplified and the manufacturing difficulty is reduced due to the fact that the non-conductive reflecting structure is added between the substrate and the conductive reflecting structure.
Fig. 7 a-7 l are schematic diagrams showing different stages of a method for manufacturing a solid-state assembled bulk acoustic wave resonator according to the present invention. The preparation method of the solid-state assembly type bulk acoustic wave resonator comprises the following steps.
In step S110, a bragg reflection structure 420 is formed on a substrate 410. In some embodiments, step S110 includes step S111 and step S112.
In step S111, a non-conductive reflective structure 421 is formed by alternately depositing high acoustic impedance layers and low acoustic impedance layers on the substrate 410.
Specifically, alternating deposition of first high acoustic impedance layers 4211 and first low acoustic impedance layers 4212 on substrate 410 forms a non-conductive reflective structure 421 (see fig. 7 a-7 b). This embodiment will be described by taking a solid-state assembled bulk acoustic wave resonator as an example shown in fig. 6. The number of periods of the non-conductive reflective structure 421 can be set according to practical situations, and is not limited to that shown in the above embodiment.
In step S112, a high acoustic impedance layer and a low acoustic impedance layer are alternately deposited on the non-conductive reflective structure 421 and patterned to form a conductive reflective structure 422.
Specifically, the second high acoustic impedance layers 4221 and the second low acoustic impedance layers 4222 are alternately deposited on the non-conductive reflective structure 421 to form a conductive reflective structure 422 (see fig. 7 c-7 f). The number of cycles of the conductive reflective structure 422 can be set according to practical situations, and is not limited to the one shown in the above embodiment.
In the present embodiment, the second high acoustic impedance layer 4221 and the second low acoustic impedance layer 4222 are patterned to partially cover the non-conductive reflective structure 421, but the present invention is not limited thereto.
In some implementations, the second high acoustic impedance layer 4221 and the second low acoustic impedance layer 4222 are both conductive materials, and the second high acoustic impedance layer 4221 and the second low acoustic impedance layer 4222 are each patterned to partially cover the non-conductive reflective structure 421.
In some implementations, the second high acoustic impedance layer 4221 is a conductive material and the second low acoustic impedance layer 4222 is a non-conductive material, the second low acoustic impedance layer 4222 completely covers the non-conductive reflective structure 421, and the second high acoustic impedance layer 4221 is patterned to partially cover the non-conductive reflective structure 421.
In some implementations, the second high acoustic impedance layer 4221 is a non-conductive material and the second low acoustic impedance layer 4222 is a conductive material, the second high acoustic impedance layer 4221 completely covers the non-conductive reflective structure 421 and the second low acoustic impedance layer 4222 is patterned to partially cover the non-conductive reflective structure 421.
In step S120, a first electrode layer 430, a piezoelectric layer 440, and a second electrode layer 450 are sequentially formed on the bragg reflection structure 420.
Specifically, a first electrode is provided on the Bragg reflection structure 420 and patterned to form a first electrode layer 430 (see FIGS. 7 g-7 h), a piezoelectric layer is provided on the first electrode layer 430 and patterned to form a piezoelectric layer 440 (see FIGS. 7 i-7 j), and a second electrode is provided on the piezoelectric layer 440 and patterned to form a second electrode layer 450 (see FIGS. 7 k-7 l).
According to the preparation method of the bulk acoustic wave resonator, the non-conductive reflecting structure and the conductive reflecting structure are sequentially formed on the substrate to serve as the Bragg reflecting structure, so that the acoustic wave transmission coefficient is not damaged, the acoustic wave can still be effectively prevented from being transmitted to the substrate through the Bragg reflecting structure, and as the non-conductive reflecting structure is made of non-conductive materials, patterning treatment is not required, the metal etching times can be reduced, and the process preparation difficulty of the Bragg reflecting structure is reduced.
Further, under the condition that the cycle number of the Bragg reflection structure is fixed, the number of layers of the non-conductive reflection structure is increased, the number of layers of the corresponding conductive reflection structure is smaller, steps generated by metal etching are smaller, the process preparation difficulty is further reduced, and the product yield is improved.
Fig. 8a to 8l are schematic views showing different stages of a method for manufacturing a solid-state assembled bulk acoustic wave resonator according to another embodiment of the present invention. The preparation method of the solid-state assembly type bulk acoustic wave resonator comprises the following steps.
In step S210, a bragg reflection structure 520 is formed on a substrate 510. In some embodiments, step S210 includes step S211 and step S212.
In step S211, high acoustic impedance layers and low acoustic impedance layers are alternately deposited on the substrate 510 to form the non-conductive reflective structure 521.
Specifically, alternating deposition of first high acoustic impedance layers 5211 and first low acoustic impedance layers 5212 on the substrate 510 forms a non-conductive reflective structure 521 (see fig. 8 a-8 b). This embodiment will be described by taking a solid-state assembled bulk acoustic wave resonator as an example shown in fig. 6. The number of periods of the non-conductive reflective structure 521 can be set according to practical situations, and is not limited to the embodiments described above.
In step S212, a high acoustic impedance layer and a low acoustic impedance layer are alternately deposited on the non-conductive reflective structure 521 and patterned to form a conductive reflective structure 522.
Specifically, second high acoustic impedance layers 5221 and second low acoustic impedance layers 5222 are alternately deposited over the non-conductive reflecting structure 521 to form a conductive reflecting structure 522 (see fig. 8 c-8 f). The number of cycles of the conductive reflective structure 522 can be set according to practical situations, and is not limited to the embodiment described above. In the present embodiment, one layer of the conductive reflective structure 522 is made of a conductive material, and the other layer is made of a non-conductive material, and only patterning the conductive material is performed to cover the non-conductive reflective structure 521 partially, but the present invention is not limited thereto.
In some implementations, the second high acoustic impedance layer 5221 is a conductive material and the second low acoustic impedance layer 5222 is a non-conductive material, the second low acoustic impedance layer 5222 completely covers the non-conductive reflecting structure 521 and the second high acoustic impedance layer 5221 is patterned to partially cover the non-conductive reflecting structure 521.
In some implementations, the second high acoustic impedance layer 5221 is a non-conductive material and the second low acoustic impedance layer 5222 is a conductive material, the second high acoustic impedance layer 5221 completely covers the non-conductive reflecting structure 521 and the second low acoustic impedance layer 5222 is patterned to partially cover the non-conductive reflecting structure 521.
In step S220, a first electrode layer 530, a piezoelectric layer 540, and a second electrode layer 550 are sequentially formed on the bragg reflection structure 520.
Specifically, a first electrode is provided on the Bragg reflection structure 520 and patterned to form a first electrode layer 530 (see FIGS. 8 g-8 h), a piezoelectric layer is provided on the first electrode layer 530 and patterned to form a piezoelectric layer 540 (see FIGS. 8 i-8 j), and a second electrode is provided on the piezoelectric layer 540 and patterned to form a second electrode layer 550 (see FIGS. 8 k-8 l).
According to the preparation method of the bulk acoustic wave resonator, the non-conductive reflecting structure and the conductive reflecting structure are sequentially formed on the substrate to serve as the Bragg reflecting structure, so that the acoustic wave transmission coefficient is not damaged, the acoustic wave can still be effectively prevented from being transmitted to the substrate through the Bragg reflecting structure, and as the non-conductive reflecting structure is made of non-conductive materials, patterning treatment is not required, the metal etching times can be reduced, and the process preparation difficulty of the Bragg reflecting structure is reduced.
Further, under the condition that the cycle number of the Bragg reflection structure is fixed, the number of layers of the non-conductive reflection structure is increased, the number of layers of the corresponding conductive reflection structure is smaller, steps generated by metal etching are smaller, the process preparation difficulty is further reduced, and the product yield is improved.
Further, one of the high acoustic impedance layer and the low acoustic impedance layer in the conductive reflecting structure is made of a conductive material, and the other one is made of a non-conductive material, and only the metal material layer is subjected to patterning treatment when the conductive reflecting structure is formed, so that the metal etching times are further reduced, and the process preparation difficulty of the Bragg reflecting structure is reduced.
Embodiments in accordance with the present invention, as described above, are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and the full scope and equivalents thereof.
Claims (10)
1. A solid-state assembly type bulk acoustic wave resonator is characterized by comprising a substrate, a Bragg reflection structure, a first electrode layer, a piezoelectric layer and a second electrode layer, wherein the Bragg reflection structure, the first electrode layer, the piezoelectric layer and the second electrode layer are sequentially laminated on the substrate;
The Bragg reflection structure comprises a non-conductive reflection structure and a conductive reflection structure, wherein the non-conductive reflection structure and the conductive reflection structure comprise high acoustic impedance layers and low acoustic impedance layers which are alternately stacked, the materials of the high acoustic impedance layers and the low acoustic impedance layers of the non-conductive reflection structure are non-conductive materials, the material of at least one layer of the high acoustic impedance layers and the low acoustic impedance layers of the conductive reflection structure is a conductive material, and the conductive material is usually metal or alloy.
2. The solid state assembled bulk acoustic wave resonator of claim 1, wherein the non-conductive reflective structure is located on and completely covers the substrate, the conductive reflective structure is located between the non-conductive reflective structure and the first electrode layer, and the conductive reflective structure partially covers the non-conductive reflective structure.
3. The solid state assembled bulk acoustic wave resonator of claim 1 wherein the non-conductive reflective structure is a first periodic structure, each first period comprising a first high acoustic impedance layer and a first low acoustic impedance layer, the first period number being at least 1, the conductive reflective structure is a second periodic structure, each second period comprising a second high acoustic impedance layer and a second low acoustic impedance layer, the second period number being at least 1.
4. The solid state mounted bulk acoustic wave resonator of claim 1 wherein the number of cycles of the bragg reflecting structure is at least 3.
5. The solid state assembled bulk acoustic wave resonator of claim 3, wherein the material of the first high acoustic impedance layer is at least one of aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, tungsten oxide, and the material of the first low acoustic impedance layer is at least one of silicon dioxide, silicon nitride, magnesium oxide, a nanoporous mixture, an aerogel, a xerogel, or a polymeric material.
6. The solid state assembled bulk acoustic wave resonator of claim 3, wherein the material of the second high acoustic impedance layer is at least one of tungsten, titanium tungsten, molybdenum, platinum, ruthenium, iridium, hafnium, tantalum, nickel, chromium, cobalt, zirconium carbide, cobalt oxide, aluminum nitride, tantalum pentoxide, hafnium oxide, aluminum oxide, silicon carbide, boron nitride, zirconium oxide, titanium oxide, tungsten oxide, and the material of the second low acoustic impedance layer is at least one of aluminum, magnesium, silicon dioxide, silicon nitride, magnesium oxide, nanoporous mixtures, aerogels, xerogels, or polymeric materials.
7. The solid state assembled bulk acoustic wave resonator of claim 1, wherein when the second high acoustic impedance layer and the second low acoustic impedance layer are both conductive materials, the second high acoustic impedance layer and the second low acoustic impedance layer partially cover the non-conductive reflective structure;
The second high acoustic impedance layer is made of conductive materials, and when the second low acoustic impedance layer is made of non-conductive materials, the second low acoustic impedance layer completely covers the non-conductive reflecting structure, and the second high acoustic impedance layer partially covers the non-conductive reflecting structure;
The second high acoustic impedance layer is made of non-conductive material, and when the second low acoustic impedance layer is made of conductive material, the second high acoustic impedance layer completely covers the non-conductive reflecting structure, and the second low acoustic impedance layer partially covers the non-conductive reflecting structure.
8. A method of making a solid state assembled bulk acoustic wave resonator as claimed in any one of claims 1 to 7, comprising:
forming a Bragg reflection structure on a substrate;
sequentially forming a first electrode layer, a piezoelectric layer and a second electrode layer on the Bragg reflection structure;
Wherein forming the Bragg reflection structure on the substrate comprises:
Alternately depositing high acoustic impedance layers and low acoustic impedance layers on a substrate to form a non-conductive reflecting structure;
alternately depositing high acoustic impedance layers and low acoustic impedance layers on the non-conductive reflecting structure and patterning to form a conductive reflecting structure;
The high acoustic impedance layer and the low acoustic impedance layer of the non-conductive reflecting structure are made of non-conductive materials, and at least one layer of the high acoustic impedance layer and the low acoustic impedance layer of the conductive reflecting structure is made of conductive materials.
9. The method of making a solid state assembled bulk acoustic wave resonator according to claim 8, wherein the high acoustic impedance layer and the low acoustic impedance layer of the conductive reflective structure are each patterned to form a conductive reflective structure, wherein the conductive reflective structure partially covers the non-conductive reflective structure.
10. The method of manufacturing a solid state assembled bulk acoustic wave resonator according to claim 8 wherein one layer of the conductive reflective structure is patterned and the other layer is not patterned to form a conductive reflective structure, wherein one layer partially covers the non-conductive reflective structure and the other layer completely covers the non-conductive reflective structure;
wherein, the material of one layer is conductive material, and the material of the other layer is non-conductive material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411274491.9A CN119154833B (en) | 2024-09-11 | 2024-09-11 | Solid-state assembly type bulk acoustic wave resonator and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411274491.9A CN119154833B (en) | 2024-09-11 | 2024-09-11 | Solid-state assembly type bulk acoustic wave resonator and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN119154833A CN119154833A (en) | 2024-12-17 |
| CN119154833B true CN119154833B (en) | 2025-06-06 |
Family
ID=93816561
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411274491.9A Active CN119154833B (en) | 2024-09-11 | 2024-09-11 | Solid-state assembly type bulk acoustic wave resonator and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119154833B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101997513A (en) * | 2009-08-20 | 2011-03-30 | 上海华为技术有限公司 | Multi-coupling filter |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6946928B2 (en) * | 2003-10-30 | 2005-09-20 | Agilent Technologies, Inc. | Thin-film acoustically-coupled transformer |
| US20120293278A1 (en) * | 2011-05-20 | 2012-11-22 | Avago Technologies Wireless Ip (Singapore) Pte. Ltd. | Stacked bulk acoustic resonator comprising distributed bragg reflector |
| CN104579233B (en) * | 2013-10-23 | 2018-12-04 | 中兴通讯股份有限公司 | A kind of production method and device of film Resonator |
| WO2018127285A1 (en) * | 2017-01-05 | 2018-07-12 | Huawei Technologies Co., Ltd. | Bragg mirror, resonator and filter device |
| CN110932694A (en) * | 2019-11-20 | 2020-03-27 | 电子科技大学 | A thin film bulk acoustic resonator |
| CN112152581B (en) * | 2020-08-24 | 2022-02-08 | 杭州星阖科技有限公司 | Bragg acoustic wave reflecting layer structure, manufacturing method thereof and solid assembled resonator |
| CN113411065A (en) * | 2021-06-18 | 2021-09-17 | 深圳市封神微电子有限公司 | Bulk acoustic wave resonator with Bragg reflection grating structure |
| US20230123285A1 (en) * | 2021-10-15 | 2023-04-20 | Skyworks Solutions, Inc. | Heat dissipation structure for laterally excited bulk acoustic wave device |
-
2024
- 2024-09-11 CN CN202411274491.9A patent/CN119154833B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101997513A (en) * | 2009-08-20 | 2011-03-30 | 上海华为技术有限公司 | Multi-coupling filter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN119154833A (en) | 2024-12-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10355195B2 (en) | Acoustic resonator and method of manufacturing the same | |
| JP4625260B2 (en) | Method for manufacturing thin film bulk resonator | |
| JP3735777B2 (en) | Resonator structure and filter having the resonator structure | |
| US7671427B2 (en) | Method of manufacturing film bulk acoustic resonator using internal stress of metallic film and resonator manufactured thereby | |
| JP4903636B2 (en) | RESONATOR, DEVICE EQUIPPED WITH THE SAME, AND METHOD FOR MANUFACTURING RESONATOR | |
| JP4490951B2 (en) | Film bulk acoustic resonator and manufacturing method thereof | |
| JP4908156B2 (en) | Thin film piezoelectric vibrator, thin film piezoelectric bulk wave resonator and high frequency filter using the same | |
| JP2008172494A (en) | Piezoelectric thin film resonator, acoustic wave device, and method of manufacturing acoustic wave device. | |
| JP2018182463A (en) | Piezoelectric thin film resonator, filter and multiplexer | |
| KR20100023892A (en) | Piezoelectric thin film resonant element and circuit component using the same | |
| CN111082776B (en) | Bulk acoustic wave resonator, filter and electronic device with electrode with void layer | |
| CN107094000A (en) | Acoustic resonator and manufacturing method thereof | |
| US20120146744A1 (en) | Acoustic wave device and method for manufacturing the same | |
| CN110868188A (en) | An ultra-high frequency resonator structure based on ring electrodes | |
| JP2008182543A (en) | Thin film piezoelectric resonator and thin film piezoelectric filter using the same | |
| CN113541636A (en) | Acoustic wave resonator and preparation method thereof | |
| CN114362708A (en) | Bulk acoustic wave resonator | |
| JP2018125696A (en) | Piezoelectric thin film resonator, filter and multiplexer | |
| CN119631300A (en) | Bulk acoustic wave device and method for manufacturing a bulk acoustic wave device | |
| CN119154833B (en) | Solid-state assembly type bulk acoustic wave resonator and preparation method thereof | |
| JP2005057707A (en) | Thin film bulk acoustic resonator and micro electromechanical system device | |
| CN113049128B (en) | Piezoelectric film type temperature sensor and preparation method thereof | |
| CN115037263A (en) | Transverse-excitation film bulk acoustic resonator and filter | |
| CN114726336B (en) | Film bulk acoustic resonator and preparation method thereof | |
| JP4693407B2 (en) | Piezoelectric thin film device and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |