WO2022052915A1

WO2022052915A1 - Filter assembly and manufacturing method therefor, and electronic device

Info

Publication number: WO2022052915A1
Application number: PCT/CN2021/116977
Authority: WO
Inventors: 庞慰; 黄源清; 张孟伦
Original assignee: 诺思(天津)微系统有限责任公司
Priority date: 2020-09-09
Filing date: 2021-09-07
Publication date: 2022-03-17
Also published as: CN114244300A

Abstract

The present disclosure relates to a filter assembly and a manufacturing method therefor. The assembly comprises a substrate and multiple filters disposed on the substrate. The multiple filters include a first filter and a second filter disposed adjacent to each other in a horizontal direction. The first filter has a first stack structure formed of multiple film layers. The second filter has a second stack structure formed of multiple film layers. Thicknesses of at least two film layers in the first stack structure are different from thicknesses of corresponding film layers in the second stack structure. The present disclosure also relates to an electronic device comprising the assembly.

Description

Filter assembly, method for manufacturing the same, and electronic device

technical field

Embodiments of the present disclosure relate to the field of semiconductors, and in particular, to a filter assembly and a method for manufacturing the same, and an electronic device.

Background technique

With the increasing development of 5G communication technology, the requirements for communication frequency bands are getting higher and higher. Traditional RF filters are limited by structure and performance and cannot meet the requirements of high-frequency communication. As a new type of BAW resonator, thin-film bulk acoustic resonator (FBAR) has the advantages of small size, light weight, low insertion loss, high frequency bandwidth and high quality factor. FBAR technology has become one of the research hotspots in the field of communication.

In existing designs, the frequency and electromechanical coupling coefficient of the filter/resonator are relatively fixed on a single wafer, which limits the integration of devices with multiple frequencies and electromechanical coupling coefficients on a single wafer.

The frequency and electromechanical coupling coefficient of the filter/resonator on a single substrate are relatively fixed, although the lift-off process and the etching method can be used to increase or decrease the thickness of some film layers to adjust, but these In the process, it is generally necessary to use organic photoresist to form specific patterns, which will cause some interface contamination and defects, which will adversely affect the growth of subsequent film layers, especially the bottom electrode and piezoelectric layer. Growing defects can lead to anomalous drop in frequency, electromechanical coupling coefficient, and Q of the resonator, which limits the integration of multiple frequency devices on a single substrate.

In addition, although the frequency of the resonator and the filter can be adjusted in a small range through the frequency adjustment layer, the adjustment range is limited.

In addition, current technologies are generally specific to a certain film layer, and there is no way to change several or all of the film layers.

In addition, as 5G requires higher and higher filter frequencies, the thickness of the film in the thickness direction of the bulk acoustic wave resonator becomes thinner and thinner, and its lateral size becomes smaller and smaller. At this time, the size of the device itself is not Then it is the main factor limiting the overall size of the device, but the package structure has become an important factor limiting the size of the device. 1A is a schematic structural diagram of a duplexer; FIG. 1B is a schematic circuit diagram of a TX filter; FIG. 1C is a schematic circuit diagram of an RX filter; FIG. 1D exemplarily shows the package structure of an existing TX filter; Figure shows the packaging structure of the existing RX filter. In the existing packaging structure, as shown in FIGS. 1D and 1E, in order to encapsulate and ensure the airtightness and reliability of use, the combined lateral dimension of the packaging ring 10, the dicing track 20, and the sealant 30 is greater than 100 microns. Greatly increases the area of the filter.

It can be seen from FIG. 1D and FIG. 1E that at present, devices of various frequencies are generally packaged separately and then integrated on the same substrate for integration, which will lead to an increase in the size of the final device.

SUMMARY OF THE INVENTION

The present disclosure is made to alleviate or solve at least one aspect of the above-mentioned problems in the prior art.

According to an aspect of the embodiments of the present disclosure, a filter assembly is proposed, comprising:

base;

A plurality of filters are arranged on the substrate, the plurality of filters include a first filter and a second filter arranged adjacent to each other in the horizontal direction, and the first filter has a plurality of film layers formed. the first stacked structure, the second filter has a second stacked structure formed by a plurality of film layers,

in:

The thicknesses of the at least two membrane layers in the first stack are different from the thicknesses of the corresponding membrane layers in the second stack.

Embodiments of the present disclosure also relate to a method for manufacturing a filter assembly, the filter assembly including at least a first filter and a second filter, the method comprising the steps of:

provide a base;

A plurality of film layers of the first filter and the second filter are sequentially formed on the substrate, the plurality of film layers of the first filter form a first laminated structure, and the plurality of film layers of the second filter form a second laminated structure structure,

in:

The method includes step A: using a mask to make thicknesses of at least two film layers of the first stacked structure different from thicknesses of corresponding film layers of the second stacked structure.

Embodiments of the present disclosure also relate to an electronic device including the filter assembly described above.

Description of drawings

These and other features and advantages of the various embodiments disclosed in this disclosure may be better understood by the following description and accompanying drawings, wherein like reference numerals refer to like parts throughout, wherein:

1A is a schematic structural diagram of a duplexer;

1B is a schematic circuit diagram of a TX filter;

Fig. 1C is the circuit schematic diagram of the RX filter;

FIG. 1D exemplarily shows the packaging structure of the existing TX filter;

FIG. 1E exemplarily shows the packaging structure of the existing RX filter;

FIG. 2 is a package structure of a duplexer according to an exemplary embodiment of the present disclosure;

3 is a schematic cross-sectional view of a filter assembly according to an exemplary embodiment of the present disclosure, wherein a plurality of BAW resonators belonging to different filters are shown, and the acoustic mirror is an acoustic mirror cavity;

4A-4K are schematic cross-sectional views exemplarily illustrating a manufacturing process of the assembly in FIG. 3 , wherein a process in which the corresponding film layer is thinned is shown;

Figures 4L-4V are schematic cross-sectional views exemplarily illustrating a manufacturing process of the assembly in Figure 3, wherein a process in which a film layer is thickened;

5 is a schematic cross-sectional view of a filter assembly according to another exemplary embodiment of the present disclosure, wherein a plurality of BAW resonators belonging to different filters are shown, and the acoustic mirror is an acoustic mirror cavity;

Fig. 6 is the partial enlarged schematic diagram of the part between two adjacent filters in Fig. 5;

7 is a schematic cross-sectional view of a filter assembly according to still another exemplary embodiment of the present disclosure, wherein BAW resonators belonging to different filters are shown, and the acoustic mirror is a Bragg reflection layer;

8 is a schematic cross-sectional view of a filter assembly according to yet another exemplary embodiment of the present disclosure, wherein only two bulk acoustic wave resonators are shown, and the film layers of the two resonators have different thicknesses;

9 is a schematic cross-sectional view of a filter assembly according to still another exemplary embodiment of the present disclosure, wherein a plurality of bulk acoustic wave resonators belonging to different filters are shown, and the pressures of adjacent resonators of adjacent filters are shown The electrical layers are disconnected from each other;

10 is a schematic cross-sectional view of a filter assembly according to still another exemplary embodiment of the present disclosure, wherein a plurality of bulk acoustic wave resonators belonging to different filters, respectively, and films of adjacent resonators of adjacent filters are shown The layer thickness is only different for the film thickness of the piezoelectric layer;

11A-11D exemplarily show a process flow diagram for thinning the bottom electrode of one of two adjacent filters;

Figures 11E-11G exemplarily show a process flow diagram for thickening the bottom electrode of one of two adjacent filters;

12A-12C exemplarily show a process flow diagram for thinning the bottom electrode of one of two adjacent filters;

13A-13C exemplarily show a process flow diagram of forming bottom electrodes of two adjacent filters with different thicknesses using a mask mask.

detailed description

The technical solutions of the present disclosure will be further specifically described below through the embodiments and in conjunction with the accompanying drawings. The following description of the embodiments of the present disclosure with reference to the accompanying drawings is intended to explain the general disclosed concept of the present disclosure, and should not be construed as a limitation of the present disclosure.

The present disclosure provides a method for designing filters with various frequencies and electromechanical coupling coefficients (corresponding to resonators in the filter) on the same substrate using a shadow mask, which can realize wide-range adjustment of frequency and electromechanical The effect of the coupling coefficient is not limited by the adjustment range.

In the present disclosure, by using the mask, a variety of filters can be freely designed on the same substrate, and the process is simple, the preparation process is pollution-free, etc., and a large frequency difference can also be realized. For example, by using the technical solution of the present disclosure, filters and radio frequency devices below 1G, 5G, 6G and even higher frequencies can be prepared on the same substrate, and finally, different filters, radio frequency devices, etc. can be integrated on a single chip (SOC integrated). Corresponding to different film thicknesses between different filters (like piezoelectric layers), in a specific embodiment, the difference in film thicknesses may be greater than 10%; there may be significant frequency differences between different filters, In specific embodiments, the frequency difference may be greater than 10%; further, in specific embodiments, the difference in electromechanical coupling coefficients between resonators of different filters may exceed 1% (eg, between 6% and 7%) difference).

In the present disclosure, by using a mask to adjust the thickness of the film layer, the size of the module, multiplexer, and multi-filter can be reduced: directly preparing devices with multiple frequencies on the same substrate can reduce the number of packaging, indirectly The size of the package structure is reduced, and ultimately the size of the entire multiplexer and module is reduced.

First of all, the reference numerals in the drawings of the present disclosure are explained as follows:

101: Substrate, optional materials are single crystal silicon, gallium nitride, gallium arsenide, sapphire, quartz, silicon carbide, diamond, etc.

102: Acoustic mirror, which can be a cavity, or a Bragg reflector and other equivalent forms.

103: Bottom electrode (including bottom electrode pins), optional materials: molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or the composite of the above metals or their alloys, etc.

112: Shadow mask, which is a mask with a specific through hole pattern, which can allow the passage of etching gas molecules, ions, plasma, etc., and temporarily combine the mask mask with the substrate when in use ( bonding), after film formation, etching and other operations, the mask mask can be removed from the substrate by a simple debonding technique. The selection of materials for the mask is very broad. In theory, any material that does not affect the etching reaction can be selected, and the material can be metal, glass, semiconductor, PCB, etc.

104: Unpatterned areas of the mask mask.

105: The figured area of the mask mask.

106: Piezoelectric layer, which can be a single crystal piezoelectric material, optional, such as: single crystal aluminum nitride, single crystal gallium nitride, single crystal lithium niobate, single crystal lead zirconate titanate (PZT), single crystal Potassium niobate, single crystal quartz film, or single crystal lithium tantalate and other materials can also be polycrystalline piezoelectric materials (corresponding to single crystal, non-single crystal materials), optional, such as polycrystalline aluminum nitride, Zinc oxide, PZT, etc., can also be a rare earth element doped material containing a certain atomic ratio of the above materials, for example, can be doped aluminum nitride, and doped aluminum nitride contains at least one rare earth element, such as scandium (Sc), yttrium (Y), magnesium (Mg), titanium (Ti), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu) and the like.

107: Top electrode (including top electrode pins), the material can be selected from molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium or a composite of the above metals or their alloys. The top and bottom electrode materials are generally the same, but can also be different.

108: Mass-loading layer, the material for forming the electrode may be selected, and the material may be the same as or different from that of the electrode.

109: A protective layer or a passivation layer, generally a dielectric material, such as silicon dioxide, aluminum nitride, silicon nitride, and the like.

110: Sacrificial layer, the material for forming the sacrificial layer may be silicon dioxide, doped silicon dioxide, and the like.

FIG. 2 is a package structure of a duplexer according to an exemplary embodiment of the present disclosure.

As mentioned above, in the existing package structure, as shown in FIGS. 1D and 1E , in order to package and ensure the airtightness and reliability of use, the package ring 10 , the dicing track 20 , the sealant 30 , and the combined lateral direction of these structures The size is greater than 100 microns, which greatly increases the area of the filter.

The mask mask has the ability to prepare small-sized patterns. Currently, patterns with a feature size of less than 500 nm and a spacing of less than 500 nm can be prepared, so the spacing and alignment accuracy of the patterns on the mask can be precisely controlled. In the present disclosure, by adopting a masking process to integrate multiple filters, as shown in FIG. 2, each single filter can save a single-sided packaging structure, which can save the area of the device; in addition, based on masking In the mask mask process, the minimum distance between the two filters (corresponding to the distance D0 shown in Figure 3 later) can be between 5μm-100μm, further, between 5μm-50μm, which is also beneficial device miniaturization.

In this disclosure, unless expressly excluded, numerical ranges are inclusive of the endpoints, furthermore, as will be understood by those skilled in the art, the median or one-third or two-thirds of the values within the numerical range may be employed.

Therefore, based on the structure shown in FIG. 2 , for example, for a duplexer, the overall die size is reduced compared to the existing package structure.

3 is a schematic cross-sectional view of a filter assembly according to an exemplary embodiment of the present disclosure, wherein a plurality of BAW resonators belonging to different filters are shown, and the acoustic mirror is an acoustic mirror cavity.

The left side in FIG. 3 shows two

resonators

201 and 204 of a first filter (eg TX filter), and the right side shows two

resonators

301 and 204 of a second filter (eg RX filter) 304. It can be seen that in FIG. 3 , the thickness of the film layer of the resonator of the second filter is smaller than the thickness of the film layer of the resonator of the first filter. Thus, two filters with different frequencies and/or electromechanical coupling coefficients (corresponding to the resonators in the filter) can be fabricated on the same substrate.

It should be pointed out that, in the claims of the present disclosure, the first and the second are only used to distinguish or name, and do not mean that the "first" and "second" in the embodiment are not the same as the "first" and "second" in the claims. "One" and "Second" are limiting.

In an exemplary embodiment of the present disclosure, the difference in thickness of the film layers may be, for example, not less than 10%, that is, the thickness of the thinner film layer does not exceed 90% of the thickness of the larger thickness film layer. Optionally, based on the different thicknesses of the film layers, the frequency difference between different filters may be, for example, not less than 10%, that is, the frequency of the filter with a smaller frequency does not exceed the frequency of the filter with a larger frequency. 90%. Optionally, based on the different thicknesses of the film layers, the difference between the electromechanical coupling coefficients between the resonators of different filters can be, for example, not less than 1%, for example, the electromechanical coupling coefficients of the resonators in one filter. is 6%, while the other is 7%.

It should be pointed out that the film structure of the filter is not limited to the film structure formed by the bottom electrode, the piezoelectric layer and the top electrode, that is, the film layer of the filter can be one of the bottom electrode, the piezoelectric layer and the top electrode. In addition to several or more, it can also be one or more of the temperature compensation layer, the mass load layer and the passivation layer, in other words, it can be the bottom electrode, the piezoelectric layer and the top electrode, the temperature compensation layer, and the mass load layer. One or more of passivation layers, etc.

In the present disclosure, the film thickness difference refers to the thickness difference between a certain film layer of one filter and the corresponding film layer of another filter.

In FIG. 3 , the resonator 201 is adjacent to the resonator 304 , and the top electrode non-connected ends of the two resonators are disconnected from each other, so that there is a distance D0 between the resonator 201 and the resonator 304 in the horizontal direction. In the present disclosure, due to the use of the mask mask process, the spacing and alignment accuracy of the patterns on the mask mask can be precisely controlled. Therefore, the distance D0 can be between 5 μm and 200 μm, and further, between 5 μm and 100 μm. between.

The angles of the steps between the film layers of different thicknesses prepared by the mask mask can be right angles (as shown in Figure 3) or non-right angles (as shown in Figures 5-6). As shown in Figure 3, the piezoelectric layers of the two filters are connected and continuous with each other, but the thickness of the piezoelectric layer of the second filter is smaller than the thickness of the piezoelectric layer of the first filter, and the piezoelectric layers of the two filters are between There is a step at the junction, and the angle of the step is a right angle of 90 degrees. The case where the angle θ of the step can be an acute angle is shown in FIGS. 5-6 . The angle θ is adjustable between 0 and 90 degrees. In the embodiment of the present disclosure, only the piezoelectric layer is shown with non-right-angled steps, but the present disclosure is not limited to this. This angle may exist for any film layer, and the corresponding film layer may be one of a bottom electrode, a piezoelectric layer and a top electrode, a temperature compensation layer, a mass loading layer, and a passivation layer.

The angle can be adjusted by the distance between the mask and the substrate. The farther the mask is from the substrate, the stronger the lateral diffusion of the etching gas/plasma and the smaller the angle; the closer the mask is to the substrate , the stronger the lateral diffusion of the etching gas/plasma, the larger the angle.

In FIGS. 3 and 5 , the non-connecting ends of the top electrodes of two adjacent resonators of different filters are disconnected from each other, and the piezoelectric layers are connected to each other, but the present disclosure is not limited thereto. 9 is a schematic cross-sectional view of a filter assembly according to still another exemplary embodiment of the present disclosure, wherein a plurality of bulk acoustic wave resonators belonging to different filters are shown, and the pressures of adjacent resonators of adjacent filters are shown The electrical layers are disconnected from each other.

7 is a schematic cross-sectional view of a filter assembly according to yet another exemplary embodiment of the present disclosure, wherein BAW resonators belonging to different filters are shown, and the acoustic mirror is a Bragg reflection layer.

8 is a schematic cross-sectional view of a filter assembly according to yet another exemplary embodiment of the present disclosure, wherein only two bulk acoustic wave resonators are shown, and the film layers of the two resonators have different thicknesses. Filters with different frequencies, electromechanical coupling coefficients (resonators within the filter) can be fabricated on the same substrate to form other radio frequency devices, such as oscillators, etc., duplexers, multiplexers, and the like.

In the above embodiments, the film layers of the first filter and the film layers of the second filter, such as the bottom electrode, the piezoelectric layer and the top electrode, all have thickness differences, but the present disclosure is not limited thereto. There can be only two film layers or one film layer with a difference in thickness. 10 is a schematic cross-sectional view of a filter assembly according to still another exemplary embodiment of the present disclosure, wherein a plurality of bulk acoustic wave resonators belonging to different filters, respectively, and films of adjacent resonators of adjacent filters are shown The layer thicknesses differ only in the film thicknesses of the piezoelectric layers.

4A-4K are cross-sectional schematic diagrams illustrating a manufacturing process of the assembly in FIG. 3 , wherein a process in which a corresponding film layer is thinned is shown.

As shown in FIG. 4A , after a cavity (ie, an acoustic mirror cavity) is formed on the surface of the substrate 101, a sacrificial material is deposited, the sacrificial material fills the cavity, and then, the sacrificial material is polished by CMP (Chemical Mechanical Polishing) method until With the exposed surface of the substrate 101, the sacrificial material in the cavity constitutes a sacrificial layer.

As shown in FIG. 4B , a metal layer corresponding to the bottom electrode is deposited on the upper surface of the structure shown in FIG. 4A .

As shown in FIG. 4C, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4C, area 105 corresponds to the filter of the right part of FIG. 4C, while area 104 corresponds to the filter of the left part of FIG. 4C. Based on this region 105, a part of the metal layer for the bottom electrode is etched or removed by particle beam, plasma or gas etchant, as shown in FIG. 4C, the metal layer for the bottom electrode on the right is reduced Thin. When in use, the mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask can be removed from the substrate by a simple debonding technique.

As shown in FIG. 4D, the metal layer for the bottom electrode formed in FIG. 4C is further patterned to form the bottom electrode 103 corresponding to each filter.

As shown in Figure 4E, a piezoelectric layer 106 is deposited on the upper surface of the structure of Figure 4D.

As shown in FIG. 4F, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4F, area 105 corresponds to the filter of the right part of FIG. 4F, while area 104 corresponds to the filter of the left part of FIG. 4F. Based on this region 105, part of the piezoelectric layer is etched or removed by particle beam, plasma or gas etchant, as shown in FIG. 4F, the piezoelectric layer on the right is thinned. When in use, the mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask can be removed from the substrate by a simple debonding technique.

As shown in FIG. 4G , a metal layer corresponding to the top electrode 107 is deposited on the upper surface of the structure of FIG. 4F .

As shown in FIG. 4H, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4H, area 105 corresponds to the filter of the right part of FIG. 4H, while area 104 corresponds to the filter of the left part of FIG. 4H. Based on this region 105, a part of the metal layer corresponding to the top electrode is etched or removed by particle beam, plasma or gas etchant, as shown in FIG. 4H, the metal layer on the right is thinned. When in use, the mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask can be removed from the substrate by a simple debonding technique.

As shown in FIG. 4I , a mass loading layer 108 and a passivation layer 109 are formed on the surface of the structure shown in FIG. 4H .

As shown in FIG. 4J , the metal layer corresponding to the top electrode is etched (thereby the passivation layer (if any) and the mass loading layer (if any) are correspondingly etched) to form the top electrode 107 . As shown in Fig. 4J, the non-connected ends of the top electrodes of adjacent resonators of the two filters are disconnected from each other. In the step shown in Figure 4J, the sacrificial layer within the cavity of the acoustic mirror is also released.

As shown in FIG. 4K, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4K, area 105 corresponds to the filter of the right part of FIG. 4K, while area 104 corresponds to the filter of the left part of FIG. 4K. Based on this region 105, a portion of the passivation layer is etched or removed by particle beam, plasma or gas etchant, as shown in the right part of Figure 4K, where the passivation layer on the right is thinned. When in use, the mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask can be removed from the substrate by a simple debonding technique.

In Figure 4K, a thinning process can be performed on the passivation layers of the two filters, respectively, using a mask mask to adjust the frequency of the filters.

Directly preparing devices with multiple frequencies on the same substrate can reduce the number of packaging. As shown in Figure 2, the size of the packaging structure is indirectly reduced, and ultimately the size of the entire multiplexer and module is reduced. Therefore, directly on a single substrate The fabrication of multi-frequency devices also plays an important role in reducing device size.

The process of thinning the film layer is not limited to the method of thinning the film layer after the film layer is formed as mentioned in the above examples, and other steps may also be used. Another method of thinning the film layer is described below by taking the formation of the thinned bottom electrode as an example.

11A-11D illustrate a process flow diagram for thinning the bottom electrode of one of two adjacent filters.

As shown in FIG. 11A , a metal layer for the bottom electrode is formed on the substrate 101 .

As shown in FIG. 11B , the metal layer on the right side is removed using a mask and the metal layer on the left side is left.

As shown in FIG. 11C , a metal layer for the bottom electrode is deposited on the structure shown in FIG. 11B , and the thickness of the metal layer of the bottom electrode on the left is finally larger than that of the bottom electrode on the right.

As shown in FIG. 11D, the metal layer for the bottom electrode formed in FIG. 11C is patterned to form the bottom electrode 103 in each filter.

12A-12C exemplarily show a process flow diagram for thinning the bottom electrode of one of two adjacent filters.

As shown in FIG. 12A , a metal layer for the bottom electrode is formed on the substrate 101 .

As shown in Figure 12B, the metal layer is patterned.

As shown in Figure 12C, the patterned metal layer on the right is thinned using a mask mask to form the bottom electrode 103 in each filter.

The above-mentioned formation method or thinning method of the bottom electrode is also applicable to other film layers of the filter, and will not be repeated here.

Referring below to FIGS. 4L-4V are schematic cross-sectional views exemplarily illustrating a manufacturing process of the assembly in FIG. 3 , wherein a process in which a film layer is thickened is shown.

As shown in FIG. 4L, after forming a cavity (ie, an acoustic mirror cavity) on the surface of the substrate 101, a sacrificial material is deposited, the sacrificial material fills the cavity, and then, the sacrificial material is polished by CMP (Chemical Mechanical Polishing) method until With the exposed surface of the substrate 101, the sacrificial material in the cavity constitutes a sacrificial layer.

As shown in FIG. 4M, a metal layer corresponding to the bottom electrode is deposited on the upper surface of the structure shown in FIG. 4L.

As shown in FIG. 4N, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4N, area 105 corresponds to the filter of the left part of FIG. 4N, while area 104 corresponds to the filter of the right part of FIG. 4N. Based on the region 105, a further layer of metal can be deposited on the metal layer of FIG. 4M, as shown in FIG. 4N, the thickness of the metal layer for the bottom electrode on the right is smaller than the thickness of the metal layer for the bottom electrode on the left . When in use, the mask mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask mask can be removed from the substrate through a simple debonding technique.

As shown in FIG. 4O, the metal layer for the bottom electrode formed in FIG. 4N is further patterned to form the bottom electrode 103 corresponding to each filter.

As shown in Figure 4P, a piezoelectric layer 106 is deposited on the upper surface of the structure of Figure 4O.

As shown in FIG. 4Q, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4Q, area 105 corresponds to the filter of the left part of FIG. 4Q, while area 104 corresponds to the filter of the right part of FIG. 4Q. Based on this region 105, additional piezoelectric layers may be deposited on the piezoelectric layer formed in FIG. 4P, as shown in FIG. 4Q, the thickness of the piezoelectric layer on the right is less than the thickness of the piezoelectric layer on the left. When in use, the mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask can be removed from the substrate by a simple debonding technique.

As shown in FIG. 4R, a metal layer corresponding to the top electrode 107 is deposited on the upper surface of the structure of FIG. 4Q.

As shown in FIG. 4S, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4S, area 105 corresponds to the filter of the left part of FIG. 4S, and area 104 corresponds to the filter of the right part of FIG. 4S. Based on the region 105, a further metal layer can be deposited on the top electrode formed in FIG. 4R. As shown in FIG. 4S, the thickness of the metal layer (top electrode) on the right side is smaller than the thickness of the metal layer (top electrode) on the left side. . When in use, the mask mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask mask can be removed from the substrate through a simple debonding technique.

As shown in FIG. 4T , a mass supporting layer 108 and a passivation layer 109 are formed on the surface of the structure shown in FIG. 4S .

As shown in FIG. 4U , the metal layer corresponding to the top electrode is etched (thereby the passivation layer (if any) and the mass loading layer (if any) are correspondingly etched) to form the top electrode 107 . As shown in FIG. 4U, the non-connected ends of the top electrodes of adjacent resonators of the two filters are disconnected from each other. In the step shown in Figure 4U, the sacrificial layer within the cavity of the acoustic mirror is also released.

As shown in FIG. 4V, a mask mask is provided, and it can be seen that the mask mask includes an area 105 with a pattern and an area 104 without a pattern. As shown in FIG. 4V, area 105 corresponds to the filter of the right part of FIG. 4V, while area 104 corresponds to the filter of the left part of FIG. 4V. Based on this region 105, a portion of the passivation layer is etched or removed by particle beam, plasma or gas etchant, as shown in the right part of FIG. 4V, the passivation layer on the right is thinned. When in use, the mask mask is temporarily bonded with the substrate, and after operations such as film formation and etching, the mask mask can be removed from the substrate through a simple debonding technique.

In FIG. 4V, a thinning process may be performed on the passivation layers of the two filters, respectively, using a mask mask to adjust the frequency of the filters.

As shown in Figure 12B, the metal layer is patterned.

11E-11G exemplarily show a process flow diagram for thickening the bottom electrode of one of two adjacent filters.

As shown in FIG. 11E , a metal layer for the bottom electrode is formed on the substrate 101 only on a portion corresponding to one filter by using a mask.

As shown in FIG. 11F , after removing the mask, a metal layer is deposited on the structure shown in FIG. 11E , and the thickness of the metal layer of the bottom electrode on the left is finally larger than that of the bottom electrode on the right. The film thickness of the metal layer.

As shown in FIG. 11G, the metal layer for the bottom electrode formed in FIG. 11F is patterned to form the bottom electrode 103 of each filter.

As shown in FIG. 13A , a metal layer for the bottom electrode is formed on the substrate 101 only on a portion corresponding to one filter by using a mask.

As shown in FIG. 13B , a metal layer for the bottom electrode is formed on the substrate 101 only on the part corresponding to the other filter by using a mask. As shown in FIG. 13B , the thickness of the metal layer on the left side is larger than that of the metal layer on the right side.

As shown in FIG. 13C, the metal layer for the bottom electrode formed in FIG. 13B is patterned to form the bottom electrode 103 in each filter.

Based on the above, the present disclosure proposes the following technical solutions:

1. A filter assembly comprising:

base;

in:

2. The assembly of 1, wherein:

The distance in the horizontal direction between the first filter and the second filter is in the range of 5 μm-200 μm.

3. The assembly according to 1, wherein:

The multiple membrane layers of the first stacked structure include a stacked first bottom electrode, a first piezoelectric layer and a first top electrode, and the multiple membrane layers of the second stacked structure include a stacked second bottom electrode, a first piezoelectric layer, and a second stacked structure. two piezoelectric layers and a second top electrode;

The thicknesses of at least two of the first bottom electrode, the first piezoelectric layer and the first top electrode are different from the thicknesses of the corresponding ones of the second bottom electrode, the second piezoelectric layer and the second top electrode.

4. The assembly of 3, wherein:

The thickness of at least two of the first bottom electrode, the first piezoelectric layer and the first top electrode is greater than at least 10% of the thickness of the corresponding one of the second bottom electrode, the second piezoelectric layer and the second top electrode.

5. The assembly of 1, wherein:

The plurality of film layers of the first stacked structure include a stacked first bottom electrode, a first piezoelectric layer, and a first top electrode, and include a first temperature compensation layer, a first mass loading layer, and a first passivation layer. At least one layer, the plurality of film layers of the second stacked structure include a stacked second bottom electrode, a second piezoelectric layer and a second top electrode, and include a second temperature compensation layer, a second mass load layer, a second at least one of the two passivation layers.

6. The assembly of 1, wherein:

the frequency of the first filter differs from the frequency of the second filter by more than 10%; and/or

The difference between the electromechanical coupling coefficient of the resonator in the first filter and the electromechanical coupling coefficient of the resonator in the second filter is not less than 1%.

7. The assembly of 1, wherein:

The film layer of the first filter is in contact with the corresponding film layer of the second filter and there is a step portion therebetween, and the angle formed by the step portion is in the range of 0-90°; or

The film layer of the first filter and the corresponding film layer of the second filter are both disconnected in the horizontal direction, or the film layer of the first filter and the corresponding film layer of the second filter are separated from the piezoelectric layer. are disconnected in the horizontal direction.

8. The assembly of any one of 1-7, wherein:

the first filter is a single RX filter and the second filter is a single TX filter; and

The assembly further includes a surrounding structure, the one surrounding structure includes a packaging ring, a dicing lane and a sealant arranged in sequence in the horizontal direction, the first filter and the second filter are simultaneously arranged on the one around the structure.

9. The assembly of 8, wherein:

The same film layers of all resonators of the first filter have the same thickness, and the same film layers of all resonators of the second filter have the same thickness.

10. A method for manufacturing a filter assembly comprising at least a first filter and a second filter, the method comprising the steps of:

provide a base;

in:

The method includes step A: using a mask to make the thickness of one film layer of the first stacked structure different from the thickness of the corresponding film layer of the second stacked structure.

11. The method according to 10, wherein:

After forming one film layer of the first laminate structure and the corresponding film layer of the second laminate structure, the method further includes reducing the thickness of the corresponding film layer using a mask mask.

12. The method according to 11, wherein:

The mask includes a non-patterned area and a patterned area, and the step A includes: making the non-patterned area at a position corresponding to the one film layer of the first stacked structure and the patterned area at a position corresponding to the corresponding film layer of the second stacked structure; and etching or removing a portion of the corresponding film layer from the patterned area to thin the corresponding film layer.

13. The method of 11, wherein:

The thinning process of reducing the thickness of the corresponding film layer is performed by using a mask mask; and

The corresponding film layers are formed based on the deposition process, the thinning process and the patterning process in sequence, or the deposition process, the patterning process and the thinning process are sequentially formed, or the deposition process, the thinning process, the deposition process and the patterning process are sequentially formed. formed.

14. The method of 10, wherein:

The step A includes: after forming one film layer of the first stacked structure and a corresponding film layer of the second stacked structure, the method further includes using a mask to deposit the one film layer thickness; or

The step A includes: after using a mask to form one layer of the one film layer by deposition, using a deposition process to form the corresponding film layer and depositing another layer on the one layer to form the One film layer, the thickness of the corresponding film layer is equal to the thickness of the other layer.

15. The method of 14, wherein:

The mask includes a non-patterned area and a patterned area, and the step A includes: making the patterned area at a position corresponding to the one film layer of the first stacked structure and the non-patterned area at a position corresponding to the corresponding film layer of the second stacked structure; and performing a deposition process on the patterned area to increase the thickness of the one film layer.

16. The method of 14, wherein:

the thickening process of increasing the thickness of the one film layer is performed by using a mask; and

The one film layer is formed based on the deposition process, the thickening process and the patterning process in sequence, or is formed based on the thickening process, the deposition process and the patterning process in sequence.

17. The method of 10, wherein:

The step A includes: forming the one film layer and the corresponding film layer in a deposition manner using a mask, and the thickness of the one film layer is different from the thickness of the corresponding film layer.

18. The method of 17, wherein:

The mask includes a non-patterned area and a patterned area, and the step A includes: when forming the one film layer, making the patterned area in the one film layer corresponding to the first stacked structure position, and the non-patterned area is in a position corresponding to the corresponding film layer of the second laminated structure; and when the corresponding film layer is formed, the patterned area is located in a position corresponding to the second laminated structure The position of the corresponding film layer of the structure, and the non-patterned area is in a position corresponding to the one film layer of the first laminated structure.

19. The method of 10, wherein:

The step A includes: using a mask to make the thicknesses of at least two film layers in the first stacked structure different from the thicknesses of the corresponding film layers in the second stacked structure.

20. The method of 10, wherein:

The plurality of film layers of the first stacked structure include a stacked first bottom electrode, a first piezoelectric layer, and a first top electrode, and include a first temperature compensation layer, a first mass loading layer, and a first passivation layer. At least one layer, the plurality of film layers of the second stacked structure include a stacked second bottom electrode, a second piezoelectric layer and a second top electrode, and include a second temperature compensation layer, a second mass load layer, a second at least one of the two passivation layers;

21. The method according to any one of 10-20, wherein:

Through step A, make: the thickness difference between the film thickness of the first filter and the corresponding film thickness of the second filter is not less than 10%; and/or the frequency of the first filter is different from that of the second filter. The frequency difference of the filters is not less than 10%; and/or the difference between the electromechanical coupling coefficient of the resonator in the first filter and the electromechanical coupling coefficient of the resonator in the second filter is not less than 1 %.

22. The method according to any one of 10-20, wherein:

The method further includes the step of encapsulating the assembly with a surrounding structure comprising a packaging ring, a dicing lane and a sealant arranged in sequence in a horizontal direction, the first filter and the second filter The devices are simultaneously arranged within the one surrounding structure.

23. An electronic device comprising the filter assembly of any of 1-9.

The electronic equipment here includes but is not limited to intermediate products such as RF front-end, filter and amplifier modules, and terminal products such as mobile phones, WIFI, and drones.

Although embodiments of the present disclosure have been shown and described, it will be understood by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present disclosure, the scope of which is determined by It is defined by the appended claims and their equivalents.

Claims

A filter assembly comprising:

base;

A plurality of filters are arranged on the substrate, the plurality of filters include a first filter and a second filter arranged adjacent to each other in the horizontal direction, and the first filter has a plurality of film layers formed. the first stacked structure, the second filter has a second stacked structure formed by a plurality of film layers,

in:

The thicknesses of the at least two membrane layers in the first stack are different from the thicknesses of the corresponding membrane layers in the second stack.
The assembly of claim 1, wherein:

The distance in the horizontal direction between the first filter and the second filter is in the range of 5 μm-200 μm.
The assembly of claim 1, wherein:

The multiple membrane layers of the first stacked structure include a stacked first bottom electrode, a first piezoelectric layer and a first top electrode, and the multiple membrane layers of the second stacked structure include a stacked second bottom electrode, a first piezoelectric layer, and a second stacked structure. two piezoelectric layers and a second top electrode;

The thicknesses of at least two of the first bottom electrode, the first piezoelectric layer and the first top electrode are different from the thicknesses of the corresponding ones of the second bottom electrode, the second piezoelectric layer and the second top electrode.
The assembly of claim 3, wherein:

The thickness of at least two of the first bottom electrode, the first piezoelectric layer and the first top electrode is greater than at least 10% of the thickness of the corresponding one of the second bottom electrode, the second piezoelectric layer and the second top electrode.
The assembly of claim 1, wherein:

The plurality of film layers of the first stacked structure include a stacked first bottom electrode, a first piezoelectric layer, and a first top electrode, and include a first temperature compensation layer, a first mass loading layer, and a first passivation layer. At least one layer, the plurality of film layers of the second stacked structure include a stacked second bottom electrode, a second piezoelectric layer and a second top electrode, and include a second temperature compensation layer, a second mass load layer, a second at least one of the two passivation layers.
The assembly of claim 1, wherein:

the frequency of the first filter differs from the frequency of the second filter by more than 10%; and/or

The difference between the electromechanical coupling coefficient of the resonator in the first filter and the electromechanical coupling coefficient of the resonator in the second filter is not less than 1%.
The assembly of claim 1, wherein:

The film layer of the first filter is in contact with the corresponding film layer of the second filter and there is a step portion therebetween, and the angle formed by the step portion is in the range of 0-90°; or

The film layer of the first filter and the corresponding film layer of the second filter are both disconnected in the horizontal direction, or the film layer of the first filter and the corresponding film layer of the second filter are separated from the piezoelectric layer. are disconnected in the horizontal direction.
The assembly of any of claims 1-7, wherein:

the first filter is a single RX filter and the second filter is a single TX filter; and

The assembly further includes a surrounding structure, the one surrounding structure includes a packaging ring, a dicing lane and a sealant arranged in sequence in the horizontal direction, the first filter and the second filter are simultaneously arranged on the one around the structure.
The assembly of claim 8, wherein:

The same film layers of all resonators of the first filter have the same thickness, and the same film layers of all resonators of the second filter have the same thickness.
A method for manufacturing a filter assembly comprising at least a first filter and a second filter, the method comprising the steps of:

provide a base;

A plurality of film layers of the first filter and the second filter are sequentially formed on the substrate, the plurality of film layers of the first filter form a first laminated structure, and the plurality of film layers of the second filter form a second laminated structure structure,

in:

The method includes step A: using a mask to make the thickness of one film layer of the first stacked structure different from the thickness of the corresponding film layer of the second stacked structure.
The method of claim 10, wherein:

After forming one film layer of the first laminate structure and the corresponding film layer of the second laminate structure, the method further includes reducing the thickness of the corresponding film layer using a mask mask.
The method of claim 11, wherein:

The mask includes a non-patterned area and a patterned area, and the step A includes: making the non-patterned area at a position corresponding to the one film layer of the first stacked structure and the patterned area at a position corresponding to the corresponding film layer of the second stacked structure; and etching or removing a portion of the corresponding film layer from the patterned area to thin the corresponding film layer.
The method of claim 11, wherein:

The thinning process of reducing the thickness of the corresponding film layer is performed by using a mask mask; and

The corresponding film layers are formed based on the deposition process, the thinning process and the patterning process in sequence, or the deposition process, the patterning process and the thinning process are sequentially formed, or the deposition process, the thinning process, the deposition process and the patterning process are sequentially formed. formed.
The method of claim 10, wherein:

The step A includes: after forming one film layer of the first stacked structure and a corresponding film layer of the second stacked structure, the method further includes using a mask to deposit the one film layer thickness; or

The step A includes: after using a mask to form one layer of the one film layer by deposition, using a deposition process to form the corresponding film layer and depositing another layer on the one layer to form the One film layer, the thickness of the corresponding film layer is equal to the thickness of the other layer.
The method of claim 14, wherein:

The mask includes a non-patterned area and a patterned area, and the step A includes: making the patterned area at a position corresponding to the one film layer of the first stacked structure and the non-patterned area at a position corresponding to the corresponding film layer of the second stacked structure; and performing a deposition process on the patterned area to increase the thickness of the one film layer.
The method of claim 14, wherein:

the thickening process of increasing the thickness of the one film layer is performed by using a mask; and

The one film layer is formed based on the deposition process, the thickening process and the patterning process in sequence, or is formed based on the thickening process, the deposition process and the patterning process in sequence.
The method of claim 10, wherein:

The step A includes: forming the one film layer and the corresponding film layer in a deposition manner using a mask, and the thickness of the one film layer is different from the thickness of the corresponding film layer.
The method of claim 17, wherein:

The mask includes a non-patterned area and a patterned area, and the step A includes: when forming the one film layer, making the patterned area in the one film layer corresponding to the first stacked structure position, and the non-patterned area is in a position corresponding to the corresponding film layer of the second laminated structure; and when the corresponding film layer is formed, the patterned area is located in a position corresponding to the second laminated structure The position of the corresponding film layer of the structure, and the non-patterned area is in a position corresponding to the one film layer of the first laminated structure.
The method of claim 10, wherein:

The multiple membrane layers of the first stacked structure include a stacked first bottom electrode, a first piezoelectric layer and a first top electrode, and the multiple membrane layers of the second stacked structure include a stacked second bottom electrode, a first piezoelectric layer, and a second stacked structure. two piezoelectric layers and a second top electrode;

The step A includes: using a mask to make the thicknesses of at least two film layers in the first stacked structure different from the thicknesses of the corresponding film layers in the second stacked structure.
The method of claim 10, wherein:

The plurality of film layers of the first stacked structure include a stacked first bottom electrode, a first piezoelectric layer, and a first top electrode, and include a first temperature compensation layer, a first mass loading layer, and a first passivation layer. At least one layer, the plurality of film layers of the second stacked structure include a stacked second bottom electrode, a second piezoelectric layer and a second top electrode, and include a second temperature compensation layer, a second mass load layer, a second at least one of the two passivation layers;

The step A includes: using a mask to make the thicknesses of at least two film layers in the first stacked structure different from the thicknesses of the corresponding film layers in the second stacked structure.
The method of any one of claims 10-20, wherein:

Through step A, make: the thickness difference between the film thickness of the first filter and the corresponding film thickness of the second filter is not less than 10%; and/or the frequency of the first filter is different from that of the second filter. The frequency difference of the filters is not less than 10%; and/or the difference between the electromechanical coupling coefficient of the resonator in the first filter and the electromechanical coupling coefficient of the resonator in the second filter is not less than 1 %.
The method of any one of claims 10-20, wherein:

the first filter is a single RX filter and the second filter is a single TX filter; and

The method further includes the step of encapsulating the assembly with a surrounding structure comprising a packaging ring, a dicing lane and a sealant arranged in sequence in a horizontal direction, the first filter and the second filter The devices are simultaneously arranged within the one surrounding structure.
An electronic device comprising the filter assembly of any one of claims 1-9.