阅读说明：本技术 声波谐振器封装件 (Acoustic wave resonator package ) 是由 李泰京 金光洙 孙晋淑 李玲揆 金成善 金尚填 于 2019-04-30 设计创作，主要内容包括：本公开提供了一种声波谐振器封装件,所述声波谐振器封装件包括：基板；声波谐振器,设置在所述基板上；盖,设置在所述基板和所述声波谐振器上；结合部,使所述基板与所述盖彼此结合,其中,所述盖包括沟槽和保护层,所述沟槽围绕所述结合部形成,并且所述保护层覆盖所述盖中的所述沟槽的表面,并且其中,所述结合部的一部分填充所述沟槽的至少一部分。(The present disclosure provides an acoustic wave resonator package comprising: a substrate; an acoustic wave resonator disposed on the substrate; a cover disposed over the substrate and the acoustic wave resonator; a bonding part bonding the substrate and the cover to each other, wherein the cover includes a groove formed around the bonding part and a protective layer covering a surface of the groove in the cover, and wherein a portion of the bonding part fills at least a portion of the groove.)

1. An acoustic wave resonator package, comprising:

a substrate;

an acoustic wave resonator disposed on the substrate;

a cover disposed over the substrate and the acoustic wave resonator; and

a coupling portion coupling the substrate and the cover to each other,

wherein the cover includes a groove formed around the bonding portion and a protective layer covering a surface of the groove in the cover, and

wherein a portion of the bond fills at least a portion of the trench.

2. The acoustic resonator package of claim 1 wherein the cover further comprises: a central portion housing the acoustic wave resonator; and an outer peripheral portion disposed outside the central portion and connected to the joint portion, and

wherein the thickness of the peripheral portion is greater than the thickness of the central portion.

3. The acoustic resonator package of claim 2 wherein a ratio of a depth of the trench to a width of the trench is in a range of 1 to 30.

4. The acoustic resonator package of claim 2 wherein the trench is formed in the outer peripheral portion.

5. The acoustic resonator package of claim 4, wherein a difference in thickness between the peripheral portion and the central portion is greater than a depth of the trench.

6. The acoustic resonator package according to claim 4, wherein the protective layer is not formed on a region of the outer peripheral portion that faces the bonding portion other than the groove.

7. The acoustic resonator package of claim 4, wherein the protective layer is formed on the entire surface of the cover except for a region of the surface of the cover that is in contact with the bonding portion.

8. The acoustic resonator package of claim 1 wherein an inner wall of the trench has a wavy shape.

9. The acoustic resonator package of claim 1 wherein said protective layer is a self-assembled monolayer.

10. The acoustic resonator package of claim 1 wherein the protective layer is formed using a material comprising fluorocarbon groups.

11. The acoustic resonator package of claim 10 wherein the protective layer has a thickness of 0.1nm to 10 nm.

12. The acoustic resonator package of claim 1 wherein the protective layer is formed using a material comprising a silane group.

13. The acoustic resonator package of claim 12 wherein the protective layer has a thickness of 10nm to 50 nm.

14. The acoustic resonator package of claim 1 wherein the bond comprises an alloy.

15. The acoustic resonator package of claim 14 wherein said alloy comprises at least two selected from the group consisting of Au, Sn, Cu, Al, Si and Ge.

16. The acoustic resonator package of claim 15 wherein the alloy comprises one or more eutectic alloys selected from the group consisting of Au-Sn, Cu-Sn, and Al-Ge.

17. The acoustic resonator package of claim 14 wherein the bond further comprises an insulating material that is the same material that forms the protective layer.

Technical Field

The following description describes an acoustic wave resonator package.

Background

Recently, with the rapid development of mobile communication devices, chemical and biological test devices, and the like, the demand for small and lightweight filters, oscillators, resonance elements, acoustic wave resonance mass sensors, and the like used in such devices has also increased.

Film Bulk Acoustic Resonators (FBARs) are known as components for realizing such small and light filters, oscillators, resonance elements, acoustic wave resonant mass sensors, and the like. The FBAR can be mass-produced at a minimum cost and can be realized to have a subminiature size. In addition, the FBAR can realize a high quality factor (Q) value (Q value is a main feature of a filter), can be used in a microwave band, and particularly can realize a frequency band of a Personal Communication System (PCS) and a frequency band of a digital radio system (DCS).

Generally, the FBAR has a structure including a resonance section realized by sequentially stacking a first electrode, a piezoelectric layer, and a second electrode on a substrate.

The operating principle of the FBAR will be described hereinafter. First, when electric energy is applied to the first electrode and the second electrode to induce an electric field in the piezoelectric layer, the electric field may generate a piezoelectric phenomenon in the piezoelectric layer to vibrate the resonance section in a predetermined direction. As a result, a bulk acoustic wave is generated in the same direction as the direction in which the resonance portion vibrates, thereby causing resonance. That is, in the FBAR (as an element using a Bulk Acoustic Wave (BAW)), an effective electromechanical coupling coefficient (Kt) of a piezoelectric body²) The increase allows the frequency characteristics of the acoustic wave element to be improved and the frequency band to be increased.

When packaging and using an acoustic wave resonator such as FBAR, the airtightness of the package including the acoustic wave resonator greatly affects the reliability of the acoustic wave resonator.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In one general aspect, an acoustic wave resonator package includes: a substrate; an acoustic wave resonator disposed on the substrate; a cover disposed over the substrate and the acoustic wave resonator; a bonding part bonding the substrate and the cover to each other, wherein the cover includes a groove formed around the bonding part and a protective layer covering a surface of the groove in the cover, wherein a portion of the bonding part fills at least a portion of the groove.

The cover may further include a central portion that houses the acoustic wave resonator, and an outer peripheral portion that is disposed outside the central portion and is connected to the joint. The thickness of the peripheral portion may be greater than the thickness of the central portion.

A ratio of a depth of the trench to a width of the trench may be in a range of 1 to 30.

The groove may be formed in the outer peripheral portion.

A difference in thickness between the peripheral portion and the central portion may be greater than a depth of the groove.

The protective layer may not be formed on an area of the outer circumferential portion facing the bonding portion other than the groove.

The protective layer may be formed on the entire surface of the cover except for a region of the surface of the cover contacting the bonding portion.

The inner wall of the groove may have a wavy shape.

The protective layer may be a self-assembled monolayer.

The protective layer may be formed using a material including a fluorocarbon group.

The protective layer may have a thickness of 0.1nm to 10 nm.

The protective layer may be formed using a material including a silane group.

The protective layer may have a thickness of 10nm to 50 nm.

The bond may comprise an alloy.

The alloy may include at least two selected from the group consisting of gold (Au), tin (Sn), copper (Cu), aluminum (Al), silicon (Si), and germanium (Ge).

The alloy may include one or more eutectic alloys selected from the group consisting of Au-Sn, Cu-Sn, and Al-Ge.

The bonding portion may further include an insulating material, which is the same material as a material forming the protective layer.

Other features and aspects will be apparent from the following detailed description, the accompanying drawings, and the claims.

Drawings

Fig. 1 is a sectional view illustrating an acoustic wave resonator package according to an embodiment.

Fig. 2 is an enlarged sectional view of the acoustic wave resonator portion in fig. 1.

Fig. 3 is a plan view of the cover in fig. 1, as viewed from the bottom side.

Fig. 4A and 4B illustrate examples of trenches and protective layers that may be used in the acoustic wave resonator package of fig. 1, where fig. 4A illustrates the prior art and fig. 4B illustrates an example of the disclosure herein.

Fig. 5 shows chemical bonds according to an example of a hydrophobic material having fluorocarbon groups.

Fig. 6 shows chemical bonds according to an example of a material comprising silane groups.

Fig. 7 to 14 illustrate a method of manufacturing an acoustic wave resonator package according to an embodiment.

Fig. 15 to 18 illustrate a method of manufacturing an acoustic wave resonator package according to an embodiment.

Like reference numerals refer to like elements throughout the drawings and the detailed description. The figures may not be drawn to scale and the relative sizes, proportions and depictions of the elements in the figures may be exaggerated for clarity, illustration and convenience.

Detailed Description

The following detailed description is provided to assist the reader in obtaining a thorough understanding of the methods, devices, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and/or systems described herein will be apparent to those skilled in the art upon review of the disclosure of this application. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but rather, variations may be made, as will be apparent upon an understanding of the present disclosure, in addition to the operations which must occur in a particular order. Moreover, descriptions of features known in the art may be omitted for greater clarity and conciseness.

The features described herein may be embodied in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways to implement the methods, devices, and/or systems described herein that will be apparent upon understanding the disclosure of the present application.

Here, it is noted that the use of the term "may" with respect to an example or embodiment (e.g., with respect to what an example or embodiment may include or implement) means that there is at least one example or embodiment that includes or implements such a feature, and all examples and embodiments are not limited thereto.

Throughout the specification, when an element such as a layer, region or substrate is described as being "on," connected to "or" coupled to "another element, it may be directly on," connected to or directly coupled to the other element or one or more other elements may be present therebetween. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there may be no intervening elements present.

As used herein, the term "and/or" includes any one of the associated listed items and any combination of any two or more.

Although terms such as "first," "second," "third," and the like may be used herein to describe various elements, components, regions, layers or sections, these elements, components, regions, layers or sections should not be limited by these terms. Rather, these terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed in connection with the examples described herein could be termed a second element, component, region, layer or section without departing from the teachings of the examples.

Spatially relative terms, such as "above," "upper," "lower," and "below," may be used herein for ease of description to describe one element's relationship to another element as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "upper" relative to another element would then be "below" or "lower" relative to the other element. Thus, the term "above" includes both an orientation of "above" and "below" depending on the spatial orientation of the device. The device may also be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative terms used herein should be interpreted accordingly.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The singular is intended to include the plural unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, quantities, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and/or combinations thereof.

Variations in the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may occur. Accordingly, the examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shapes that occur during manufacturing.

The features of the examples described herein may be combined in various ways as will be apparent after understanding the disclosure of the present application. Further, while the examples described herein have a variety of configurations, other configurations are possible as will be apparent upon understanding the disclosure of the present application.

Fig. 1 is a sectional view illustrating an acoustic wave resonator package 10 according to an embodiment. Fig. 2 is an enlarged sectional view of the acoustic wave resonator portion in fig. 1. Fig. 3 is a plan view of the cover 220 in fig. 1, as viewed from the bottom side. Further, fig. 4A and 4B illustrate examples of a trench T and a protective layer 230 that can be used for the acoustic wave resonator package 10 of fig. 1, where fig. 4A illustrates the prior art and fig. 4B illustrates an example of the present disclosure.

Referring to fig. 1 to 4B, the acoustic wave resonator package 10 may include a substrate 110, an acoustic wave resonator 100, a cover 220, and a bonding portion 210. The cover 220 may include a groove T formed around the bonding portion 210 and a protective layer 230 covering at least a surface where the groove T is formed. Further, at least a portion of the groove T of the cover 220 may be filled with the bonding portion 210.

Referring to fig. 1 and 2, the acoustic wave resonator 100 may be a Film Bulk Acoustic Resonator (FBAR). Hereinafter, a description will be given taking a film bulk acoustic resonator as an example. The acoustic wave resonator 100 may include a substrate 110, an insulating layer 115, a film layer 150, a cavity C, a resonance part 120, and a protective layer 127.

The substrate 110 may be a silicon substrate. For example, a silicon wafer or a silicon-on-insulator (SOI) type substrate may be used as the substrate 110. The insulating layer 115 may be disposed on an upper surface of the substrate 110 to electrically isolate the substrate 110 and the resonance part 120 from each other. In addition, the insulating layer 115 may prevent the substrate 110 from being etched by an etching gas when the cavity C is formed in the process of manufacturing the acoustic wave resonator. In this example, the insulating layer 115 may utilize silicon dioxide (SiO)₂) Silicon nitride (Si)₃N₄) Oxygen, oxygenAluminium (Al)₂O₃) And aluminum nitride (AlN), and may be formed on the substrate 110 through any one of a chemical vapor deposition process, a Radio Frequency (RF) magnetron sputtering process, and an evaporation process.

The sacrificial layer 140 may be formed on the insulating layer 115, and the cavity C and the etch stopper 145 may be formed in the sacrificial layer 140. The cavity C may be an empty space and may be formed by removing a portion of the sacrificial layer 140. Since the cavity C is formed in the sacrificial layer 140, the resonance part 120 formed on the sacrificial layer 140 may be completely flat. The etch stopper 145 may be disposed along a boundary of the cavity C. The etch preventing part 145 may be provided to prevent etching from being performed outside the cavity region in the process of forming the cavity C. Accordingly, a horizontal area of the cavity C may be defined by the etch stopper 145, and a vertical area of the cavity C may be defined by the thickness of the sacrificial layer 140.

The film layer 150 may be formed on the sacrificial layer 140 to define the thickness (or height) of the cavity C together with the substrate 110. Therefore, the film 150 may be formed using a material that is not easily removed in the process of forming the cavity C. For example, when a halide-based (e.g., fluorine (F), chlorine (Cl), etc.) etching gas is used to remove a portion (e.g., a cavity region) of the sacrificial layer 140, the layer 150 may be formed using a material having low reactivity with the above-mentioned etching gas. In this case, the film 150 may include silicon dioxide (SiO)₂) And silicon nitride (Si)₃N₄) One or two of them. Furthermore, the film 150 may include manganese oxide (MnO), magnesium oxide (MgO), zirconium oxide (ZrO)₂) Aluminum nitride (AlN), lead zirconate titanate (PZT), gallium arsenide (GaAs), hafnium oxide (HfO)₂) Alumina (Al)₂O₃) Titanium oxide (TiO)₂) And zinc oxide (ZnO), or may be a metal layer containing at least one selected from the group consisting of aluminum (Al), nickel (Ni), chromium (Cr), platinum (Pt), gallium (Ga), and hafnium (Hf). However, the configuration of the film layer 150 is not limited to the examples provided herein.

A seed layer (not shown) formed using aluminum nitride (AlN) may be formed on the film layer 150. The seed layer may be disposed between the film layer 150 and the first electrode 121. The seed layer may be formed using a metal or a dielectric substance having a hexagonal close-packed (HCP) structure, in addition to AlN. In the case of forming the seed layer using a metal, the seed layer may be formed using, for example, titanium (Ti). The resonance part 120 may include a first electrode 121, a piezoelectric layer 123, and a second electrode 125. The resonance part 120 may include a first electrode 121, a piezoelectric layer 123, and a second electrode 125 stacked in this order from a lower portion of the resonance part 120. Accordingly, in the resonance section 120, the piezoelectric layer 123 may be disposed between the first electrode 121 and the second electrode 125.

Since the resonance part 120 is formed on the film layer 150, the first electrode 121, the piezoelectric layer 123, and the second electrode 125 may be sequentially stacked on the substrate 110, thereby forming the resonance part 120. The resonance part 120 may resonate the piezoelectric layer 123 according to signals applied to the first electrode 121 and the second electrode 125 to generate a resonance frequency and an anti-resonance frequency. In the case of forming the insertion layer 170 (to be described below), the resonance section 120 may be divided into a central portion S in which the first electrode 121, the piezoelectric layer 123, and the second electrode 125 are substantially flatly stacked, and an extension portion E in which the insertion layer 170 is interposed between the first electrode 121 and the piezoelectric layer 123. The central portion S may be a region disposed at the middle of the resonance portion 120, and the extension portion E may be a region disposed along the periphery of the central portion S. Thus, the extension E may be a region extending outward from the central portion S. The insertion layer 170 may include an inclined surface L having a thickness that increases as a distance from the central portion S increases. In the extension E, the piezoelectric layer 123 and the second electrode 125 may be disposed on the insertion layer 170. Accordingly, portions of the piezoelectric layer 123 and the second electrode 125 located in the extension E may have inclined surfaces that are inclined according to the shape of the insertion layer 170.

In the embodiment of fig. 1 and 2, the extension E is included in the resonance part 120, and thus resonance may also be generated in the extension E. However, the position where resonance is generated is not limited to this example. That is, according to the structure of the extension portion E, resonance may not be generated in the extension portion E, but resonance may be generated only in the central portion S. The first electrode 121 and the second electrode 125 may be formed using an electrical conductor, for example, using gold, molybdenum, ruthenium, iridium, aluminum, platinum, titanium, tungsten, palladium, tantalum, chromium, nickel, or a metal containing any one or any combination of two or more of gold, molybdenum, ruthenium, iridium, aluminum, platinum, titanium, tungsten, palladium, tantalum, chromium, nickel, but are not limited to these examples. In the resonance part 120, the area of the first electrode 121 may be larger than that of the second electrode 125, and the first metal layer 180 may be disposed on the first electrode 121 along the outer side of the first electrode 121. Accordingly, the first metal layer 180 may be disposed to surround the second electrode 125.

The first electrode 121 is disposed on the film layer 150 and thus may be completely flat. The second electrode 125 is disposed on the piezoelectric layer 123 and thus may have a curvature formed to correspond to the shape of the piezoelectric layer 123. The second electrode 125 may be disposed in the entire central portion S, and may be partially disposed in the extension E. Accordingly, the second electrode 125 may include a portion disposed on a piezoelectric portion 123a (described below) of the piezoelectric layer 123 and a portion disposed on a bending portion 123b (described below) of the piezoelectric layer 123. In more detail, the second electrode 125 may be disposed to cover the entire piezoelectric portion 123a of the piezoelectric layer 123 and a portion of the inclined portion 1231. Accordingly, the area of the portion of the second electrode 125 disposed in the extension portion E may be smaller than the area of the inclined surface of the inclined portion 1231, and the area of the portion of the second electrode 125 disposed in the resonance portion 120 may be smaller than the area of the piezoelectric layer 123.

A piezoelectric layer 123 may be formed on the first electrode 121. In the case of forming an insertion layer 170 (described below), the piezoelectric layer 123 may be formed on the first electrode 121 and the insertion layer 170. Zinc oxide (ZnO), aluminum nitride (AlN), doped aluminum nitride, lead zirconate titanate, quartz, or the like may be selectively used as the material of the piezoelectric layer 123. The doped aluminum nitride may also include rare earth metals, transition metals, or alkaline earth metals. For example, the rare earth metal may include any one or any combination of any two or more of scandium (Sc), erbium (Er), yttrium (Y), and lanthanum (La), and the content of the rare earth metal may be 1 to 20 atomic percent (at%) based on the total content of the doped aluminum nitride. The transition metal may include at least one selected from the group consisting of hafnium (Hf), titanium (Ti), zirconium (Zr), tantalum (Ta), and niobium (Nb). Further, the alkaline earth metal may include magnesium (Mg).

The piezoelectric layer 123 may include a piezoelectric portion 123a provided in the central portion S and a bending portion 123b provided in the extension portion E. The piezoelectric portion 123a may be a portion directly stacked on the upper surface of the first electrode 121. Accordingly, the piezoelectric portion 123a may be interposed between the first electrode 121 and the second electrode 125, thereby being formed flat together with the first electrode 121 and the second electrode 125. The bending portion 123b may be a region extending outward from the piezoelectric portion 123a and disposed in the extension portion E. The bent portion 123b may be disposed on the insertion layer 170, and may protrude along the shape of the insertion layer 170. Accordingly, the piezoelectric layer 123 may be curved at the boundary between the piezoelectric portion 123a and the curved portion 123b, and the curved portion 123b may protrude according to the thickness and shape of the insertion layer 170. The bent portion 123b may include an inclined portion 1231 and an extended portion 1232. The inclined portion 1231 may be a portion inclined along the inclined surface L of the insertion layer 170. Further, the extension portion 1232 may refer to a portion extending outward from the inclined portion 1231. The inclined portion 1231 may be formed to be disposed in parallel with the inclined surface L of the insertion layer 170, and the inclination angle of the inclined portion 1231 may be the same as that of the inclined surface L of the insertion layer 170.

The insertion layer 170 may be disposed along a surface formed by the film layer 150, the first electrode 121, and the etch preventing layer 145. The insertion layer 170 may be disposed near the central portion S and may support the bending portion 123b of the piezoelectric layer 123. Accordingly, the bending part 123b of the piezoelectric layer 123 may include the inclined part 1231 and the extension part 1232 configured according to the shape of the insertion layer 170. The insertion layer 170 may be disposed in an area other than the central portion S. For example, the insertion layer 170 may be provided in the entire region except the central portion S or in a part of the region except the central portion S.

Further, at least a portion of the insertion layer 170 may be disposed between the piezoelectric layer 123 and the first electrode 121. The side surface of the insertion layer 170 disposed along the boundary of the central portion S may have a form in which the thickness of the insertion layer 170 increases as the distance from the central portion S increases. Accordingly, the side surface of the insertion layer 170 disposed adjacent to the central portion S may be an inclined surface L having a predetermined inclination angle. When the inclination angle of the side surface of the insertion layer 170 is less than 5 °, in order to manufacture the insertion layer 170, the thickness of the insertion layer 170 needs to be very small or the area of the inclined surface L needs to be particularly large, which is basically difficult to achieve. Further, when the inclination angle of the side surface of the insertion layer 170 is greater than 70 °, the inclination angle of the inclined portion 1231 of the piezoelectric layer 123 stacked on the insertion layer 170 may also be greater than 70 °.

In the case where the inclination angle of the side surface of the insertion layer 170 is larger than 70 °, since the piezoelectric layer 123 is excessively bent, a crack may be generated in the bent portion of the piezoelectric layer 123. Therefore, in the disclosed embodiment, the inclination angle of the inclined surface L may be formed in a range of greater than or equal to 5 ° and less than or equal to 70 °. The insertion layer 170 may utilize materials such as silicon dioxide (SiO)₂) Aluminum nitride (AlN), aluminum oxide (Al)₂O₃) Silicon nitride (Si)₃N₄) Manganese oxide (MnO) or zirconium oxide (ZrO)₂) But may be formed using a material different from that of the piezoelectric layer 123. Further, if necessary, the region in which the insertion layer 170 is disposed may be an empty space. This may be achieved by removing the insertion layer 170 after the resonance part 120 is completely formed in the manufacturing process. The insertion layer 170 may be formed to have the same or similar thickness as that of the first electrode 121. In addition, the insertion layer 170 may be formed to have a thickness smaller than that of the piezoelectric layer 123. In the case where the thickness of the insertion layer 170 is smaller than that of the piezoelectric layer 123, the inclined portion of the piezoelectric layer 123 may be formed by the insertion layer and cracks or the like may not occur, which may contribute to improving the performance of the resonator 100. The thickness of the insertion layer 170 may not have a specific lower limit, but in order to easily adjust the deposition thickness and ensure uniformity of the thickness of the deposited wafer, the thickness of the insertion layer 170 may be

Or larger.

The resonance part 120 may be disposed to be separated from the substrate 110 by a cavity C (empty space). The cavity C may be formed by supplying an etching gas (or etchant) to the introduction hole to remove a portion of the sacrificial layer 140 in a process of manufacturing the acoustic wave resonator. A protective layer 127 may be provided along the surface of the acoustic wave resonator 100 to protect the acoustic wave resonator 100 from the outside. The protective layer 127 may be disposed along the surface formed by the second electrode 125, the bent portion 123b of the piezoelectric layer 123, and the insertion layer 170. The protective layer 127 may be formed using any one selected from the group consisting of a silicon oxide-based insulating material, a silicon nitride-based insulating material, an aluminum oxide-based insulating material, and an aluminum nitride-based insulating material. Further, a protective layer 127 may be additionally provided on the substrate between the acoustic wave resonator 100 and the bonding portion 210.

The first electrode 121 and the second electrode 125 may extend to the outside of the resonance part 120, and the first metal layer 180 may be disposed on an upper surface of the extension part of the first electrode 121, and the second metal layer 190 may be disposed on an upper surface of the extension part of the second electrode 125. The first and second metal layers 180 and 190 may be formed using a material such as gold (Au), gold-tin (Au-Sn) alloy, copper (Cu), copper-tin (Cu-Sn) alloy, aluminum (Al), aluminum-germanium (Al-Ge) alloy, or the like. The first metal layer 180 and the second metal layer 190 may be configured as connection wirings that electrically connect the first electrode 121 and the second electrode 125 of the acoustic wave resonator 100 to an electrode of another acoustic wave resonator disposed adjacent to the acoustic wave resonator 100, or may be configured as external connection terminals. However, first metal layer 180 and second metal layer 190 are not limited to the examples provided. Although an example in which the insertion layer 170 is removed below the second metal layer 190 is shown in fig. 1, the configuration of the acoustic wave resonator package 10 is not limited to this example. That is, if necessary, the acoustic wave resonator package 10 may also be implemented in a structure in which the insertion layer 170 is provided below the second metal layer 190. The first metal layer 180 may penetrate the insertion layer 170 and the protection layer 127, and may be bonded to the first electrode 121. Further, as shown in fig. 2, the first electrode 121 may be formed to have an area larger than that of the second electrode 125, and the first metal layer 180 may be formed in an outer circumferential portion of the first electrode 121. Accordingly, the first metal layer 180 may be disposed along the outer circumference of the resonance part 120 so as to surround the first electrode 121.

As described above, the second electrode 125 may be stacked on the piezoelectric portion 123a of the piezoelectric layer 123 and the inclined portion 1231. Further, the portion of the second electrode 125 disposed on the inclined portion 1231 of the piezoelectric layer 123 (i.e., the portion of the second electrode 125 disposed in the extension portion E) may not be disposed on the entire inclined surface of the inclined portion 1231, but may be disposed on only a portion of the inclined surface of the inclined portion 1231.

The cover 220 may be disposed on the substrate 110 and the acoustic wave resonator 100, and may be bonded to the substrate 110 through the bonding portion 210. The cover 220 may be configured to protect the acoustic wave resonator 100 from the external environment, and may be formed in the form of a cover having an internal space in which the acoustic wave resonator 100 is accommodated. For example, as shown in fig. 1, the cover 220 may include a central portion 221 and an outer peripheral portion 222, the central portion 221 accommodating the acoustic wave resonator, and the outer peripheral portion 222 being disposed outside the central portion 221 and connected to the joint 210. In this example, the thickness of the peripheral portion 222 may be greater than the thickness of the central portion 221. The material of the cover 220 is not particularly limited, and may be, for example, a silicon wafer.

In the disclosed embodiment, as shown in fig. 1 and 3, the groove T of the cover 220 may be formed around the joint 210, and in this case, the groove T may be provided at the outer circumferential portion 222 of the cover 220. In the process of bonding the cover 220 to the substrate 110, the bonding portion 210 may have fluidity, and in this case, a portion of the bonding portion 210 may flow in a lateral direction to fill at least a portion of the trench T. In the drawing, it is illustrated that the bonding portion 210 fills the entire region of the trench T, but a portion of the trench T may not be filled with the bonding portion 210.

As described above, the groove T reduces the bonding portion 210 in a flowing state flowing into the outer periphery of the groove T, and can reduce the occurrence of defects due to contact between the bonding portion 210 and the acoustic wave resonator 100 or the bonding portion 210 flowing out to the outside of the acoustic wave resonator package 10. As shown in fig. 9, the difference in thickness between the outer peripheral portion 222 and the central portion 221 (i.e., the depth d2 of the cavity formed in the central portion 221) may be greater than the depth d1 of the groove T. This form can be realized in the process of forming the cavity of the central portion 221 and the trench T by the same etching process. The depth of the trench T may vary depending on the size of the acoustic wave resonator package 10, the size of the lid 220, and the like, and for example, the trench T may have a depth of about 10 μm to about 20 μm. Further, the ratio of the depth of the trench T to the width of the trench T (i.e., aspect ratio) may be 1 or more. In the case where the ratio of the depth to the width of the trench is less than 1, there is a disadvantage in that the area of the bonding region increases and the overall size of the device increases. In the case where the ratio of the depth to the width of the trench is greater than 30, it may be difficult to achieve the shape of the trench T, and it may be impossible to sufficiently fill the metal material of the bonding portion in the trench T and it is difficult to ensure sufficient airtightness.

The cap 220 may include a protective layer 230, and the protective layer 230 covers a surface where the trench T is formed. The protective layer 230 may cover other surfaces of the cap 220 except for the surface where the trench T is formed. However, as shown in fig. 1, the protection layer 230 may not be formed in the remaining region of the outer circumferential portion 222 of the cover 220 facing the bonding portion 210 except for the groove T, and this form may be obtained in a process of stripping a photo mask (PR) layer for forming the groove T (as described below). Further, as described below with reference to fig. 14, the protective layer 230 may not cover the outer side surface of the cover 220. The reason is that when dicing is performed on each package unit after the wafer-level bonding process, the protective layer 230 is not formed on the outer side surface of the cover 220 exposed by the dicing.

If the junction 210 is to penetrate and contact the trench T, diffusion or chemical reaction may occur between the junction 210 and the trench T, and defects may occur in the junction 210. For example, in the case where a silicon (Si) wafer is used as the cover 220 and an Au — Sn process alloy is used as the bonding part 210, such a defect may occur if Si is diffused into the bonding part 210 or if Au and Sn are diffused into the substrate 110. If such a defect occurs as described above, the airtightness of the acoustic wave resonator package 10 may decrease and the reliability of the acoustic wave resonator package 10 may also decrease because the bonding force between the cover 220 and the substrate 110 will decrease. Accordingly, in the disclosed embodiment, the protective layer 230 is disposed to cover the surface of the trench T to significantly reduce contact between the bonding portion 210 and the cap 220 during the bonding process.

In the disclosed embodiment, the protective layer 230 may be implemented by, for example, a molecular vapor deposition process. The molecular vapor deposition process can form a layer of molecular units having functional groups that function with materials having end groups such as: the material is readily adsorbed to the substrate by gas phase chemical reactions. Further, in the protective layer 230, a conformal coating may be applied thereto, and the protective layer 230 may be deposited to the sidewalls of the trenches having a large aspect ratio with a uniform thickness, and since the protective layer 230 is deposited by a vapor phase chemical reaction, the protective layer 230 may be deposited at a temperature lower than a deposition temperature of a liquid chemical reaction. The protective layer 230 formed by the molecular vapor deposition process described above may be formed as a self-assembled monolayer, and the deposition process may be performed at a relatively low temperature (e.g., 50 ℃ or less). Since the formation temperature of the protection layer 230 is low, the protection layer 230 may be effectively formed in a state where a PR mask layer for a trench T process is formed, and may also be thinly and uniformly formed in the trench T. Since a commonly used Chemical Vapor Deposition (CVD) process is performed at a high temperature, the CVD process may be difficult to perform in a state where a PR mask layer is present. In addition, the protective layer 230 may be formed thin and uniform as compared to the case of using a conventional CVD process, thereby sufficiently securing a space of the trench T. For example, as shown in fig. 4A, in the case of dry etching of a Si substrate, when etching and passivation of Si are repeated, a fan-shaped region of a wave shape may appear on the inner surface of the trench (T). In the case where the protection layer 330 is formed by using a Plasma Enhanced Chemical Vapor Deposition (PECVD) process, which is generally used in the related art, the entrance of the trench may be narrow since it is difficult to perform conformal deposition on the protection layer 330. Unlike the related art, as shown in fig. 4B, even when the inner surface of the trench T has a wavy shape, the protective layer 230 may be formed to have a uniform and thin thickness.

As an example in which the protective layer 230 is implemented as a self-assembled monolayer, the protective layer 230 may include a fluorine component, and may be formed using, for example, a hydrophobic material including a fluorocarbon group. In this case, the protective layer 230 may have a very thin thickness (e.g., a thickness of 0.1nm to 10 nm). In this example, a hydrophobic material may be defined as a material that has a contact angle with water of 90 ° or greater after deposition. Fig. 5 shows an example of a hydrophobic material having a fluorocarbon group by chemical bonding. In detail, the protection layer 230 may include fluorine (F) component, and may also include fluorine (F) and silicon (Si).

As another example, the protective layer 230 may be formed using a material including a silicon component. In detail, the protective layer 230 may be formed using a material including a silane group (e.g., siloxane). Fig. 6 shows the chemical bonds for such a protective layer 230. In the case where the protective layer 230 is formed using siloxane, the thickness of the protective layer 230 may be greater than that of a material having a fluorocarbon group. For example, the thickness of the protective layer 230 may be about 10nm to about 100 nm. For example, the protective layer 230 may have a thickness of 10nm to 50 nm. In the case where the thickness of the protective layer formed using siloxane is less than 10nm, it is difficult to effectively prevent silicon (Si) and bonding metals (such as Au, Sn, etc.) of the substrate from being diffused. In addition, in the case where the thickness of the protective layer is greater than 100nm, since the deposition process is excessively performed, process efficiency may be reduced and the volume of the trench T may be reduced.

As described above, the bonding portion 210 can maintain airtightness in the acoustic wave resonator package 10 by bonding the cover 220 and the substrate 110 to each other. The bonding part 210 may include an alloy, and the alloy may include at least two selected from the group consisting of gold (Au), tin (Sn), copper (Cu), aluminum (Al), silicon (Si), and germanium (Ge), for example, a processing alloy such as Au-Sn, Cu-Sn, Al-Ge, and the like. In more detail, the joint 210 may include a parent material, a molten material, and an alloy of the parent material and the molten material, which are generally used for eutectic bonding (eutectic bonding) or metal diffusion bonding. For example, the parent material may include copper (Cu), gold (Au), silver (Ag), nickel (Ni), aluminum (Al), lead (Pb), etc., and the molten material may include tin (Sn), indium (In), silicon (Si), zinc (Zn), germanium (Ge), etc. Further, the alloy of the parent material and the molten material may include Au₃Sn、Cu₃Sn, Al-Ge, etc., but are not limited thereto.

As shown in fig. 1, a plurality of via holes 112 penetrating the substrate 110 may be formed in the lower surface of the substrate 110. Further, the connection conductors 115a and 115b may be formed in the respective via holes 112. The connection conductors 115a and 115b may be formed on the inner surface (e.g., the entire inner wall) of the via hole 112, but are not limited to this configuration. The connection conductors 115a and 115b may have first ends connected to the external electrodes 117a and 117b formed on the lower surface of the substrate 110 and second ends electrically connected to the first electrode 121 or the second electrode 125. For example, the first connection conductor 115a may electrically connect the first electrode 121 and the external electrode 117a to each other, and the second connection conductor 115b may electrically connect the second electrode 125 and the external electrode 117b to each other. Although only two via holes 112 and two connection conductors 115a and 115b are shown and described in fig. 1, the number of via holes 112 and the number of connection conductors 115a and 115b are not limited thereto, and the number of via holes and the number of connection conductors may be greater than 2, if necessary.

The acoustic wave resonator package 10 may be used to perform various functions. For example, a plurality of acoustic wave resonators 100 may be provided in the acoustic wave resonator package 10, and in this case, depending on the arrangement of the plurality of acoustic wave resonators 100, a ladder filter structure, a lattice filter structure, or a combined filter structure of a ladder filter structure and a lattice filter structure may be realized.

Hereinafter, an example of a method of manufacturing the acoustic wave resonator package 10 will be described with reference to fig. 7 to 14. In fig. 7 to 14, only the cover 220 and the substrate 110 around the bonding portion 210 are shown, and other components are not shown.

First, as shown in fig. 7, a cap 220 in the form of a silicon (Si) wafer or the like may be provided. In this case, the coating 250 for protecting the cap 220 may be formed on the surface of the cap 220, and the coating 250 may be formed using a thermal oxide layer, a ceramic layer (e.g., AlN), or the like. However, the coating 250 may not be applied to the surface of the cover 220, and in this case, the cover 220 may have the same form as that described in the above-described embodiment.

Next, as shown in fig. 8, the first bonding portion 211 and the mask layer 240 may be formed on one region of the cap 220 (e.g., a peripheral portion of the cap 220). The first bonding portion 211 may be connected to the second bonding portion of the substrate 110 to form a bonding structure of the package, and may be formed using a material such as gold (Au), tin (Sn), copper (Cu), aluminum (Al), silicon (Si), germanium (Ge), or the like. As a representative example of the above materials, the first bonding portion 211 may be formed using tin (Sn). The mask layer 240 is provided to form a cavity and a trench of a central portion in the cap 220, and the mask layer 240 may be formed using a Photoresist (PR) or the like.

Next, as shown in fig. 9, a cavity and a groove T may be formed through an etching process, and thus the cover 220 may be divided into a central portion 221 and a peripheral portion 222. The present etching process may appropriately utilize a semiconductor etching process, and may be performed by, for example, dry etching the lid 220 in the form of a silicon wafer. In this case, as described above, the depth d2 of the cavity of the central portion 221 may be greater than the depth d1 of the groove T of the outer circumferential portion 222. In this case, as described above, the ratio (i.e., aspect ratio) of the depth d1 to the width w1 of the trench T may be in the range of 1 to 30.

As such, in the embodiment of fig. 7 to 14, after the first bonding portion 211 and the mask layer 240 are formed, the trench T may be formed. Conventionally, after forming a trench through a mask layer, a first bonding portion is formed by using an additional mask layer, and in this case, it is difficult to peel off the additional mask layer formed in the trench. Further, since the protective layer is formed after the first bonding portion is formed, an additional process of removing the protective layer after the process of bonding the cover and the substrate to each other may be required.

Next, as shown in fig. 10, a protective layer 230 may be formed on the surface of the cap 220, and during the process of forming the protective layer 230 on the surface of the cap, the protective layer 230 may also be formed on the surface of the mask layer 240. The protective layer 230 may be formed using a self-assembled monolayer using a molecular vapor deposition process as described above, and may be obtained at a temperature of 50 ℃ or less, and may be uniformly formed in the trench T. Then, as shown in fig. 11, the mask layer 240 may be removed by using a lift-off process or the like. Accordingly, a portion of the protection layer 230 covering the mask layer 240 may be removed, and the first bonding portion 211 may be exposed. Since the process of stripping and removing the mask layer 240 formed using PR or the like is relatively simple and the first bonding portion 211 is exposed by such a process, an additional etching process for exposing the first bonding portion 211 may not be required.

Next, as shown in fig. 12, a bonding process may be performed by bonding the first bonding portion 211 of the cover 220 and the second bonding portion 212 of the substrate 110 to each other, and the bonding portion 210 shown in fig. 13 may be obtained through such a bonding process, thereby forming a bonded structure of the cover 220 and the substrate 110. The second bonding portion 212 may be formed using a material such as gold (Au), tin (Sn), copper (Cu), aluminum (Al), silicon (Si), germanium (Ge), or the like, and may be formed using the same material as that of the electrodes 121 and 125 of the acoustic wave resonator 100 for process efficiency. As such an example, the second bonding part 212 may include gold (Au), and may form a eutectic alloy with a tin (Sn) component of the first bonding part 211. The bonding process of the first and second bonding parts 211 and 212 may be performed at a temperature (about 300 ℃) at which materials (e.g., tin (Sn) and gold (Au)) included in the first and second bonding parts 211 and 212 may form an intermetallic phase. During the bonding process, the first and second bonding portions 211 and 212 may have fluidity to spread toward the surroundings, and may be accommodated by the groove T so as not to flow out of the acoustic wave resonator 100 or to the outside. Further, the first and second bonding portions 211 and 212 may not directly contact the cover 220 due to the protective layer 230 for protecting the groove T, thereby maintaining airtightness.

The above-described example of the method of manufacturing the acoustic wave resonator package 10 shows the process of the package unit, but a wafer-level process may also be used in order to improve efficiency. Fig. 14 illustrates a wafer-level bonding process in which dicing is performed for each package unit in a state where the bonding portion 120 is formed (i.e., a state where the substrate 110 and the cover 220 are bonded to each other). In this case, the outer side surface of the cover 220 may not be covered with the protective layer 230 in the region corresponding to the cutting line D. Further, such a wafer-level bonding process may also be applied to the embodiments shown in fig. 15 to 18, which will be described below.

Fig. 15 to 18 illustrate a method of manufacturing an acoustic wave resonator package according to an embodiment. With the change of the manufacturing method, a difference occurs in the structure of the acoustic wave resonator package.

First, the form shown in fig. 15 may be formed by stripping the mask layer after the process of forming the trench of the embodiment described above with reference to fig. 7 to 14. In other words, in the embodiment of fig. 15 to 18, the protection layer 230 may be formed in a state where the mask layer is not present. Then, the bonding process of fig. 17 and 18 may be performed, and the protective layer 230 may be interposed between the first bonding portion 211 and the second bonding portion 212. Accordingly, the bonding portion 210 may further include an insulating material 231. Here, the insulating material 231 may be the same material as that forming the protective layer 230. In other words, the residual component of the protective layer 230 may exist within the bonding portion 210. Further, as shown in fig. 18, the protective layer 230 may be formed on the entire surface of the cover 220 except for the region in contact with the bonding part 210 to more effectively protect the cover 220.

As set forth above, according to the embodiments disclosed herein, the acoustic wave resonator package may have excellent airtightness between the substrate and the cover, thereby effectively protecting the acoustic wave resonator contained therein. The acoustic wave resonator package described herein can significantly reduce the influence from the external environment, thereby having improved reliability.

Although the present disclosure includes specific examples, it will be apparent upon an understanding of the present disclosure that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects in each example should be considered applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques were performed in a different order and/or if components in the described systems, architectures, devices, or circuits were combined in a different manner and/or replaced or added by other components or their equivalents. Therefore, the scope of the present disclosure is defined not by the detailed description but by the claims and their equivalents, and all modifications within the scope of the claims and their equivalents will be understood to be included in the present disclosure.