WO2020097829A1

WO2020097829A1 - Film bulk acoustic wave resonator and manufacturing method therefor, and filter

Info

Publication number: WO2020097829A1
Application number: PCT/CN2018/115445
Authority: WO
Inventors: 李平; 王伟; 胡念楚; 贾斌
Original assignee: 开元通信技术（厦门）有限公司
Priority date: 2018-11-14
Filing date: 2018-11-14
Publication date: 2020-05-22

Abstract

The present disclosure provides a film bulk acoustic wave resonator and a manufacturing method therefor, and a filter. The film bulk acoustic wave resonator comprises: a substrate; a piezoelectric stack structure formed on the substrate, the piezoelectric stack structure comprising a bottom electrode, a piezoelectric film, and a top electrode; as well as a first pad and a second pad formed on the piezoelectric stack structure. The film bulk acoustic wave resonator further comprises a dielectric layer, formed on an etched end surface of the piezoelectric film and/or formed on etched end surfaces of the piezoelectric film and the bottom electrode, and/or formed on etched end surfaces of the piezoelectric film and the top electrode, and/or formed on etched end surfaces of the piezoelectric film, the top electrode, and the bottom electrode. The film bulk acoustic wave resonator and the manufacturing method therefor, and the filter of the present disclosure improve the device performance, simplify the manufacturing process, and reduce the manufacturing cost.

Description

Thin film bulk acoustic wave resonator and its manufacturing method and filter

Technical field

The present disclosure belongs to the technical field of wireless communication, and more particularly relates to a thin film bulk acoustic wave resonator, a manufacturing method thereof, and a filter.

Background technique

With the development of mobile communication technology, the requirements for data transmission rate are higher and higher, more and more frequency bands are used for communication, and the electromagnetic spectrum is more and more crowded. This aspect requires more filter devices to ensure that there is no interference between various communication frequency bands. On the other hand, it requires filters and other chips to have lower losses to ensure that the terminal is in the case of increasing number of chips The increased power consumption of the product matches the increase in battery capacity.

Filters used in mobile communications, especially smartphones, currently have two main technologies: surface acoustic wave technology (SAW: Surface Acoustic Wave) and bulk acoustic wave technology (BAW: Bulk Acoustic Wave). SAW filters have been widely used in the 2G and 3G era because of their simple structure and manufacturing process, low cost, and small size. However, with the popularization of 4G and the advancement of 5G, the communication frequency continues to increase. The operating frequency is inversely proportional to the width of the interdigital electrode (IDT: Interdigital Transducer). When the communication frequency becomes higher and higher, the width of the IDT will become narrower and narrower. This aspect increases the manufacturing difficulty. On the other hand, due to IDT Narrowing, the electrode loss increases, and the power capacity of the device will also decrease. Therefore, the SAW technology is not suitable for high frequencies, especially the frequency band greater than 3.5 GHz. The working frequency of the BAW filter is inversely proportional to the thickness of the film, so it can work at a higher frequency. Studies have shown that the BAW filter can meet the needs of mobile communications in the range of 1.5GHz to 9GHz.

Thin film bulk acoustic resonators are the basic components of BAW filters, and their performance directly affects the performance of BAW filters. At present, thin-film bulk acoustic wave devices using BAW technology mainly have two types: air gap type and solid state assembly type.

The existing thin film bulk acoustic resonator mainly has the following defects:

(1) The bottom electrode, piezoelectric film, top electrode, etc. need to be deposited step by step, and the process steps such as photolithography and etching in the middle will cause the surface morphology of the film to deteriorate, affecting the quality of the subsequent film deposition, and thus affecting the bulk acoustic wave Device performance.

(2) The etching requirements of the bottom electrode are high, and the end surface of the bottom electrode needs to be etched into a slope with a small angle, which is difficult in process and low in production efficiency.

Summary of the invention

(1) Technical problems to be solved

In view of the above problems, the present disclosure provides a thin film bulk acoustic wave resonator, a manufacturing method thereof, and a filter to at least partially solve the above technical problems.

(2) Technical solution

According to an aspect of the present disclosure, a method for manufacturing a thin film bulk acoustic resonator includes:

Deposit the bottom electrode and the piezoelectric film on the substrate successively;

Patterning the piezoelectric film, exposing part of the bottom electrode;

Graphic bottom electrode;

Deposit a dielectric layer and etch the dielectric layer;

Deposit a top electrode and pattern the top electrode; and

Make pads.

According to another aspect of the present disclosure, a method for manufacturing a thin film bulk acoustic resonator includes:

Deposit the bottom electrode, piezoelectric film and top electrode in sequence on the substrate;

The top electrode, the piezoelectric film and the bottom electrode are sequentially patterned;

Deposit a dielectric layer and etch the dielectric layer; and

Make pads.

Further, under vacuum conditions, the bottom electrode and the piezoelectric film are successively deposited by magnetron sputtering method; or the bottom electrode, the piezoelectric film and the top electrode are successively deposited by magnetron sputtering method;

Use spin coating or chemical vapor deposition to deposit the dielectric layer;

The dielectric layer is etched using a full-face dry etching process to retain the dielectric layer at the end surface of the piezoelectric film; or the photolithography and etching processes are used to retain the dielectric layer at at least one end surface of the piezoelectric film.

Further, the top electrode pattern is defined by one photolithography;

The top electrode and the piezoelectric film are sequentially etched by dry etching or wet etching; and

The bottom electrode is patterned through photolithography and etching processes.

Further, in the step of making pads, two pads are made: a first pad is in contact with the top electrode, a second pad is formed on the bottom electrode, and the first pad is The width of the overlapping area of the top electrode is greater than or equal to 1um.

Further, before depositing the bottom electrode, it further includes: making an acoustic reflection unit on the substrate.

Further, in the step of making pads, two pads are made: a first pad is made on the top electrode, a second pad is made on the bottom electrode, and the first pad is The width of the overlapping area of the acoustic reflection unit is greater than or equal to 0.1um.

Further, before depositing the bottom electrode, it further includes: forming an isolation layer on the substrate.

According to yet another aspect of the present disclosure, a thin film bulk acoustic resonator is provided, including:

Substrate

A piezoelectric stack structure formed on the substrate, the piezoelectric stack structure including a bottom electrode, a piezoelectric film, and a top electrode; and

A first pad and a second pad formed on the piezoelectric stack structure;

Wherein, the thin film bulk acoustic wave resonator further includes a dielectric layer formed on the etched end surface of the piezoelectric film, and / or formed on the etched end surface of the piezoelectric film and the bottom electrode, and // Or formed on the etched end surfaces of the piezoelectric film and the top electrode, and / or formed on the etched end surfaces of the piezoelectric film, the top electrode and the bottom electrode.

Further, the dielectric layer part is formed in an area enclosed by the piezoelectric stack structure and the substrate, the top electrode includes at least three parts, a first part is located on the substrate, and a second part Is located on the dielectric layer, the third part is located on the piezoelectric film, and the second part connects the first part and the third part; or

The dielectric layer is partially formed in the area enclosed by the first pad, the piezoelectric stack structure, and the substrate, and the top electrode is located on the piezoelectric film.

Further, the side surface of the dielectric layer formed on the etched end surfaces of the piezoelectric film and the bottom electrode is in contact with the inner surface of the top electrode, and the bottom surface includes two parts with a height difference, the two One of the parts is in contact with the substrate, and the other is in contact with the bottom electrode;

The bottom surface of the dielectric layer formed on the etched end surface of the piezoelectric film is in contact with the bottom electrode.

Further, the second pad is formed on the bottom electrode, and is located outside the dielectric layer formed on the etched end surface of the piezoelectric film.

Further, the thin film bulk acoustic resonator further includes an acoustic reflection unit on the substrate; the dielectric layer is formed on the etched end surfaces of the piezoelectric film and the bottom electrode, and the etching of the piezoelectric film The etched end face; the first pad is formed on the top electrode, and the width of the overlapping area with the acoustic reflection unit is greater than or equal to 0.1um.

Further, the side surface of the dielectric layer formed on the etched end surfaces of the piezoelectric film, the top electrode and the bottom electrode is in contact with the inner surface of the first pad, and the bottom surface is in contact with the substrate;

The bottom surface of the dielectric layer formed on the etched end surfaces of the piezoelectric film and the top electrode is in contact with the bottom electrode.

Further, the dielectric layer is formed on the etched end surfaces of the piezoelectric film, top electrode and bottom electrode, and the etched end surfaces of the piezoelectric film and top electrode; the first pad and the top electrode The width of the overlapping area is greater than or equal to 1um.

Further, the second pad is formed on the bottom electrode, and is located outside the dielectric layer formed on the etched end surfaces of the piezoelectric film and the top electrode.

Further, it further includes: an isolation layer formed between the bottom electrode and the substrate.

According to still another aspect of the present disclosure, there is provided a filter including a plurality of the thin film bulk acoustic resonators cascaded.

(3) Beneficial effects

It can be seen from the above technical solutions that the thin film bulk acoustic resonator of the present disclosure, its manufacturing method, and the filter have at least one of the following beneficial effects:

(1) By continuously depositing the piezoelectric film and the bottom electrode, the roughening of the surface of the bottom electrode during photolithography and etching is avoided to adversely affect the subsequent deposition quality of the piezoelectric film.

(2) By continuously depositing the top electrode, piezoelectric film and bottom electrode, the influence of the photolithography and etching processes on the surface of the intermediate film layer is reduced, thereby improving the quality of thin film deposition and improving product performance. At the same time, the patterning of the top electrode and the piezoelectric film can be realized by one-step photolithography, which reduces the manufacturing steps and the manufacturing cost.

(3) The thin film bulk acoustic resonator includes the arc-shaped dielectric layer, which is beneficial to improve the step coverage effect and achieve effective isolation; the dielectric layer is formed on the etched end surface of the piezoelectric film, and / or is formed on the pressure The etched end surfaces of the electric film and the bottom electrode, and / or the etched end surfaces of the piezoelectric film and the top electrode, and / or the etched end surfaces of the piezoelectric film, the top electrode, and the bottom electrode. As a result, an acoustic impedance discontinuity is formed at the boundary of the resonator, which can reflect the energy leaked laterally, thereby improving the performance of the bulk acoustic wave resonator.

BRIEF DESCRIPTION

In order to more clearly explain the technical solutions in the embodiments of the present disclosure, the drawings required in the description of the embodiments will be briefly described below. Obviously, the drawings in the following description are only some embodiments of the present disclosure. Those of ordinary skill in the art can obtain other drawings based on these drawings without paying any creative labor.

FIG. 1 is a schematic structural diagram of a thin film bulk acoustic resonator according to Embodiment 1 of the present disclosure.

2-9 are schematic diagrams of a manufacturing process of a thin film bulk acoustic resonator according to Embodiment 1 of the present disclosure.

FIG. 10 is a schematic structural diagram of a thin film bulk acoustic resonator according to Embodiment 2 of the present disclosure.

11-17 are schematic diagrams of a manufacturing process of a thin film bulk acoustic resonator according to Embodiment 2 of the present disclosure.

detailed description

In order to make the purpose, technical solutions and advantages of the present disclosure more clear, the present disclosure will be further described in detail in conjunction with specific embodiments and with reference to the accompanying drawings.

The present disclosure provides a thin film bulk acoustic resonator, including:

Substrate

A first pad and a second pad formed on the piezoelectric stack structure;

Wherein, the thin film bulk acoustic wave resonator further includes a dielectric layer formed on the etched end surface of the piezoelectric film, and / or formed on the etched end surface of the piezoelectric film and the bottom electrode, and / or Formed on the etched end surfaces of the piezoelectric film and the top electrode, and / or formed on the etched end surfaces of the piezoelectric film, the top electrode and the bottom electrode.

As a result, an acoustic impedance discontinuity is formed at the boundary of the resonator, and the energy leaked laterally can be reflected, thereby improving the performance of the bulk acoustic wave resonator.

Specifically, the dielectric layer may include two parts: a first part may be formed in an area surrounded by the piezoelectric stack structure and the substrate, or may be formed on the first pad, the pressure Within the area enclosed by the electrical stack structure and the substrate; a second portion may be formed between the piezoelectric stack structure and the second pad.

More specifically, for the thin film bulk acoustic resonator of the present disclosure, the first portion of the dielectric layer is formed in the area enclosed by the piezoelectric stack structure and the substrate; the top electrode may include at least three In part, the first part is on the substrate, the second part is on the dielectric layer, the third part is on the piezoelectric film, and the second part connects the first and third parts. Of course, the thin film bulk acoustic wave resonator may further include an acoustic reflection unit on the substrate, the first pad is formed on the top electrode, and the width of the overlapping area with the acoustic reflection unit is greater than or It is equal to 0.1um, which is conducive to the formation of acoustic impedance discontinuity at the edge of the resonator and improve the Q value of the resonator.

Alternatively, the first portion of the dielectric layer is formed in the area surrounded by the first pad, the piezoelectric stack structure, and the substrate, and the top electrode is located on the piezoelectric film. The width of the overlapping area between the first pad and the top electrode is greater than or equal to 1 um, which is beneficial to reduce the connection resistance and form a discontinuous acoustic impedance at the boundary, and improve the Q value of the resonator.

Preferably, the dielectric layer has an arc shape, which is beneficial to improve the step coverage effect and achieve effective isolation. In addition, the thin film bulk acoustic resonator of the present disclosure may optionally include an isolation layer to further improve the performance of the thin film bulk acoustic resonator.

The present disclosure provides a method for manufacturing a thin film bulk acoustic resonator, including:

Patterning the piezoelectric film, exposing part of the bottom electrode;

Graphic bottom electrode;

Deposit a dielectric layer and etch the dielectric layer;

Deposit a top electrode and pattern the top electrode; and

Make pads.

The present disclosure also provides another method for manufacturing a thin film bulk acoustic resonator, including:

Deposit a dielectric layer and etch the dielectric layer; and

Make pads.

The thin film bulk acoustic resonator of the present disclosure and the manufacturing method thereof will be described in detail below in conjunction with Embodiment 1 and Embodiment 2.

Example one

As shown in FIG. 1, the thin film bulk acoustic resonator of this embodiment includes: a substrate 1, an acoustic reflection unit 2, an isolation layer 3, a bottom electrode 4, a piezoelectric thin film 5,

dielectric layers

6a, 6b, a top electrode 7, and a

solder Plates

8a, 8b.

The acoustic reflection unit 2 is formed on the substrate 1, and the surface of the acoustic reflection unit is flush with the surface of the substrate. The isolation layer 3 is formed on the substrate and the acoustic reflection unit. The bottom electrode 4 is formed on the isolation layer. The dielectric layer 6a is formed on the etched end surface of the piezoelectric film and the bottom electrode, and the dielectric layer 6b is formed on the etched end surface of the piezoelectric film. The first part of the top electrode 7 is located on the isolation layer, the second part is located on the dielectric layer 6a, the third part is located on the piezoelectric film, and the second part connects the first and third parts. The pad 8a is formed on the first and second portions of the top electrode, and the pad 8b is formed on the bottom electrode and is located outside the dielectric layer 6b.

Wherein, the substrate may be silicon (Si), glass, sapphire (sapphire), gallium nitride (GaN), gallium arsenide (GaGs), lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), etc. .

The acoustic reflection unit may be an air cavity or a Bragg reflection layer formed by alternately stacking materials with different high and low acoustic impedances.

The isolation layer may be an insulating material such as silicon oxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), or the like.

The bottom electrode may be molybdenum (Mo), tungsten (W), chromium (Cr), aluminum (Al), copper (Cu), iridium (Ir), ruthenium (Ru), silicon (Si), graphene (Graphene ), One or more combinations of carbon nanotubes (Carbon Nanotube).

The piezoelectric film may be aluminum nitride (AlN), zinc oxide (ZnO), lead zirconate titanate (PZT), or the above-mentioned materials doped with rare earth elements.

The dielectric layer may be dielectric materials such as silicon oxide (SiO2), silicon glass (USG), phosphorosilicate glass (PSG), borosilicate glass (BSG), borophospho glass (BPSG), orthosilicate (TEOS)

The top electrode may be molybdenum (Mo), tungsten (W), chromium (Cr), aluminum (Al), copper (Cu), iridium (Ir), ruthenium (Ru), silicon (Si), graphene (Graphene ), One or more combinations of carbon nanotubes (Carbon Nanotube).

The pad may be one or more combinations of chromium (Cr), nickel (Ni), tungsten (W), titanium tungsten (TiW), aluminum (Al), copper (Cu), and gold (Au).

As shown in FIGS. 2-9, the manufacturing process of the thin film bulk acoustic resonator of this embodiment is as follows:

S1, an acoustic reflection unit is fabricated on the substrate, please refer to FIG. 2. Optionally, the substrate is etched to form a trench, filled with sacrificial material and then polished to form an acoustic reflection unit on the substrate.

S2, deposit the isolation layer, bottom electrode, and piezoelectric film in sequence, for example, by magnetron sputtering, in which the vacuum is not broken in the middle of the deposition, and after the deposition of a layer of film is completed, the substrate is transferred into the next layer of film in a high vacuum environment The deposition chamber continues to be deposited until the deposition of the isolation layer, bottom electrode, and piezoelectric film is completed, as shown in FIG. 3.

S3, the piezoelectric film is patterned, and part of the bottom electrode is exposed, please refer to FIG. 4. Optionally, the piezoelectric film is etched using photolithography, dry etching or wet etching methods.

S4, the patterned bottom electrode, please refer to Figure 5. Optionally, photolithography, dry etching or wet etching methods are used.

S5, the deposited dielectric layer, please refer to FIG. 6. Alternatively, the dielectric layer is deposited by spin coating or chemical vapor deposition. Since the step at the end surface of the piezoelectric film is higher, a thicker dielectric material is deposited at the end surface than in other regions.

S6. Etching the dielectric layer. By controlling the etching conditions, the dielectric layer is removed at all positions except the piezoelectric layer at the end of the piezoelectric film. Typically, this step uses a full-face dry etching process without photolithography. Since the thickness of the dielectric at the end of the piezoelectric film is the thickest, by accurately controlling the etching time, the dielectric layer is only retained at the end of the piezoelectric film , Please refer to Figure 7.

S7, deposit and pattern the top electrode, please refer to FIG. 8. Optionally, photolithography and etching processes are used.

S8, making pads, wherein, referring to FIG. 9, the pads connected to the top electrode extend into the acoustic reflection unit and form an overlap with the acoustic emission unit. The width of the overlapping area is greater than or equal to 0.1um, which is beneficial to the The acoustic impedance discontinuous at the edge of the resonator increases the Q value of the resonator.

Example 2

As shown in FIG. 10, the thin film bulk acoustic resonator of this embodiment includes: a substrate 1, an acoustic reflection unit 2, an isolation layer 3, a bottom electrode 4, a piezoelectric thin film 5,

dielectric layers

6a, 6b, a top electrode 7, and a

solder Plates

8a, 8b.

The acoustic reflection unit 2 is formed on the substrate 1, and the surface of the acoustic reflection unit is flush with the surface of the substrate. The isolation layer 3 is formed on the substrate and the acoustic reflection unit. The bottom electrode 4 is formed on the isolation layer. The dielectric layer 6a is formed on the etched end surfaces of the top electrode, piezoelectric film and bottom electrode, and the dielectric layer 6b is formed on the etched end surfaces of the top electrode and piezoelectric film. The top electrode 7 is located on the piezoelectric film. A first part of the pad 8a is formed on the isolation layer, a second part is formed on the dielectric layer 6a, a third part is formed on the top electrode, and the second part connects the first part and the third part. The pad 8b is formed on the bottom electrode and is located outside the dielectric layer 6b.

The material of each layer can be the same as that in the first embodiment. The difference from the first embodiment is that in the manufacturing process of the second embodiment, the isolation layer, the bottom electrode, the piezoelectric film, and the top electrode are continuously deposited without breaking the vacuum, and then Using the same lithography mask, the top electrode and piezoelectric film are etched away at the same time.

As shown in FIGS. 11-17, the manufacturing process of the thin film bulk acoustic resonator of this embodiment is as follows:

S1, making an acoustic reflection unit, please refer to FIG. 11. Optionally, a method of etching the substrate to form a trench, filling the sacrificial material and then polishing is used to fabricate the acoustic reflection unit.

S2, deposit the isolation layer, bottom electrode, piezoelectric film and top electrode in sequence, for example, using magnetron sputtering method, in which the vacuum is not broken in the middle of the deposition, after the completion of the deposition of a thin film, the substrate is transferred into The deposition of a thin film deposition chamber continues until the deposition of the isolation layer, bottom electrode, piezoelectric film, and top electrode is completed, as shown in FIG. 12.

S3, pattern the top electrode and the piezoelectric film in sequence. Typically, the top electrode pattern is defined by one photolithography, and the shape of the top electrode is formed by dry etching or wet etching, and then the top electrode is used to mask Die, using dry or wet etching method to etch the piezoelectric film, please refer to Figure 13.

S4, patterned bottom electrode, please refer to FIG. 14. Optionally, photolithography and etching processes are used to pattern the bottom electrode.

S5, depositing a dielectric layer, for example, using spin coating or chemical vapor deposition to deposit the dielectric layer. Due to the higher step at the end face of the piezoelectric film, a thicker dielectric material will be deposited at the end face than in other areas, please refer to FIG. 15 Show.

S6. Etching the dielectric layer. By controlling the etching conditions, the dielectric layer is removed at all positions except for the dielectric layer at the end of the piezoelectric film. Typically, this step uses a full-face dry etching process without photolithography. Since the thickness of the dielectric at the end of the piezoelectric film is the thickest, by accurately controlling the etching time, the dielectric layer is only retained at the end of the piezoelectric film , Please refer to Figure 16.

S7, making a pad. Please refer to FIG. 17, the overlap width of the pad connected to the top electrode and the top electrode is greater than or equal to 1um, which is beneficial to reduce the connection resistance and form a discontinuous acoustic impedance at the boundary. Increase the Q value of the resonator.

In addition, the present disclosure also provides a filter including a plurality of the thin film bulk acoustic resonators cascaded.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present disclosure in detail. It should be understood that the above are only specific embodiments of the present disclosure and are not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of this disclosure shall be included in the protection scope of this disclosure.

So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the present disclosure.

It should be noted that, in the drawings or the text of the description, the implementations not shown or described are all forms known to those of ordinary skill in the art, and are not described in detail. In addition, the above definitions of various elements and methods are not limited to the various specific structures, shapes, or modes mentioned in the embodiments, and those of ordinary skill in the art may simply modify or replace them.

(1) The present disclosure may also include a passivation layer covering all areas where the top electrode is not contacted by the pad, and all areas where the bottom electrode is not covered by the pad and the piezoelectric film.

(2) The present disclosure may also not use an isolation layer.

(3) The dielectric layer of the present disclosure can also be removed during subsequent etching to form an air interface around the piezoelectric film.

Of course, according to actual needs, the method of the present disclosure also includes other steps. Since it has nothing to do with the innovation of the present disclosure, it will not be repeated here.

In addition, the above definitions of various elements and methods are not limited to the various specific structures, shapes, or modes mentioned in the embodiments, and those of ordinary skill in the art may simply modify or replace them.

It should be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only the directions referring to the drawings, not To limit the scope of protection of this disclosure. Throughout the drawings, the same elements are denoted by the same or similar reference signs. When it may cause confusion to the understanding of the present disclosure, the conventional structure or configuration will be omitted. In addition, the shapes and sizes of the components in the figures do not reflect the actual sizes and proportions, but only illustrate the contents of the embodiments of the present disclosure. In addition, in the claims, any reference signs between parentheses should not be constructed to limit the claims.

Unless well-known as contrary, the numerical parameters in this specification and the appended claims are approximate and can be changed according to the desired characteristics obtained through the disclosure. Specifically, all numbers used in the specification and claims to indicate the content of the composition, reaction conditions, etc., should be understood as modified by the word "about" in all cases. In general, the meaning of the expression means to include a specific amount of ± 10% change in some embodiments, ± 5% change in some embodiments, ± 1% change in some embodiments, in some implementations In the case of ± 0.5% change.

Furthermore, the word "comprising" or "including" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "one" before an element does not exclude the presence of multiple such elements.

The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., are used to modify the corresponding element, which does not mean that the element has any ordinal number, nor Represents the order of an element and another element, or the order of manufacturing methods. The use of these ordinal numbers is only used to make a certain element with a certain name can be clearly distinguished from another element with the same name.

Similarly, it should be understood that in order to streamline the disclosure and help understand one or more of the various disclosed aspects, in the above description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together into a single embodiment, Figure, or its description. However, the disclosed method should not be interpreted as reflecting the intention that the claimed disclosure requires more features than those explicitly recited in each claim. Rather, as reflected in the following claims, the disclosed aspects lie in less than all features of a single disclosed embodiment. Therefore, the claims that follow the specific implementation are hereby expressly incorporated into the specific implementation, where each claim itself serves as a separate embodiment of the present disclosure.

Claims

A method for manufacturing a thin film bulk acoustic resonator, including:

Deposit the bottom electrode and the piezoelectric film on the substrate successively;

Patterning the piezoelectric film, exposing part of the bottom electrode;

Graphic bottom electrode;

Deposit a dielectric layer and etch the dielectric layer;

Deposit a top electrode and pattern the top electrode; and

Make pads.
A method for manufacturing a thin film bulk acoustic resonator, including:

Deposit the bottom electrode, piezoelectric film and top electrode in sequence on the substrate;

The top electrode, the piezoelectric film and the bottom electrode are sequentially patterned;

Deposit a dielectric layer and etch the dielectric layer; and

Make pads.
The production method according to claim 1 or 2, wherein

Under vacuum conditions, the bottom electrode and the piezoelectric film are successively deposited by the magnetron sputtering method; or the bottom electrode, the piezoelectric film and the top electrode are successively deposited by the magnetron sputtering method;

Use spin coating or chemical vapor deposition to deposit the dielectric layer;

The dielectric layer is etched using a full-face dry etching process to retain the dielectric layer at the end surface of the piezoelectric film; or the photolithography and etching processes are used to retain the dielectric layer at at least one end surface of the piezoelectric film.
The production method according to claim 2, wherein

The top electrode pattern is defined by one photolithography;

The top electrode and the piezoelectric film are sequentially etched by dry etching or wet etching; and

The bottom electrode is patterned through photolithography and etching processes.
The production method according to claim 2, wherein

In the step of making pads, two pads are made: a first pad is in contact with the top electrode, a second pad is formed on the bottom electrode, and the first pad is in contact with the top electrode The width of the overlapping area is greater than or equal to 1um.
According to the manufacturing method of claim 1 or 2, before depositing the bottom electrode, further comprising: manufacturing an acoustic reflection unit on the substrate.
The manufacturing method according to claim 6, wherein in the step of manufacturing the pads, two pads are fabricated: a first pad is fabricated on the top electrode, and a second solder is fabricated on the bottom electrode In the disk, the width of the overlapping area of the first pad and the acoustic reflection unit is greater than or equal to 0.1um.
According to the manufacturing method of claim 1 or 2, before depositing the bottom electrode, further comprising: forming an isolation layer on the substrate.
A thin film bulk acoustic resonator, including:

Substrate

A piezoelectric stack structure formed on the substrate, the piezoelectric stack structure including a bottom electrode, a piezoelectric film, and a top electrode; and

A first pad and a second pad formed on the piezoelectric stack structure;

Wherein, the thin film bulk acoustic wave resonator further includes a dielectric layer formed on the etched end surface of the piezoelectric film, and / or formed on the etched end surface of the piezoelectric film and the bottom electrode, and // Or formed on the etched end surfaces of the piezoelectric film and the top electrode, and / or formed on the etched end surfaces of the piezoelectric film, the top electrode and the bottom electrode.
The thin film bulk acoustic resonator according to claim 9, wherein

The dielectric layer is partially formed in an area enclosed by the piezoelectric stack structure and the substrate, the top electrode includes at least three parts, a first part is located on the substrate, and a second part is located on the On the dielectric layer, a third part is located on the piezoelectric film, and a second part connects the first part and the third part; or

The dielectric layer is partially formed in the area enclosed by the first pad, the piezoelectric stack structure, and the substrate, and the top electrode is located on the piezoelectric film.
The thin film bulk acoustic resonator according to claim 9, wherein

The side surface of the dielectric layer formed on the etched end surfaces of the piezoelectric film and the bottom electrode is in contact with the inner surface of the top electrode, and the bottom surface includes two parts with a height difference One of them is in contact with the substrate, and the other is in contact with the bottom electrode;

The bottom surface of the dielectric layer formed on the etched end surface of the piezoelectric film is in contact with the bottom electrode.
The thin film bulk acoustic wave resonator according to claim 11, wherein the second pad is formed on the bottom electrode and is located on the dielectric layer formed on the etched end surface of the piezoelectric film Outside.
The thin film bulk acoustic resonator according to claim 9, wherein

The thin film bulk acoustic wave resonator further includes an acoustic reflection unit on the substrate; the dielectric layer is formed on the etched end surfaces of the piezoelectric film and the bottom electrode, and the etched end surface of the piezoelectric film; The first pad is formed on the top electrode, and the width of the overlapping area with the acoustic reflection unit is greater than or equal to 0.1 um.
The thin film bulk acoustic resonator according to claim 9, wherein

The side surface of the dielectric layer formed on the etched end surfaces of the piezoelectric film, the top electrode and the bottom electrode is in contact with the inner surface of the first pad, and the bottom surface is in contact with the substrate;

The bottom surface of the dielectric layer formed on the etched end surfaces of the piezoelectric film and the top electrode is in contact with the bottom electrode.
The thin film bulk acoustic resonator according to claim 9, wherein the dielectric layer is formed on the etched end surfaces of the piezoelectric film, top electrode and bottom electrode, and the etched end surfaces of the piezoelectric film and top electrode ; The width of the overlapping area of the first pad and the top electrode is greater than or equal to 1um.
The thin film bulk acoustic resonator according to claim 14, wherein the second pad is formed on the bottom electrode and is located on the etched end surface formed on the piezoelectric film and the top electrode The outer side of the dielectric layer.
The thin film bulk acoustic resonator according to claim 9, further comprising: an isolation layer formed between the bottom electrode and the substrate.
A filter comprising a cascaded plurality of thin film bulk acoustic resonators according to any one of claims 9-17.