TW202023081A - Acoustic resonator and method of manufacturing thereof - Google Patents

Abstract

An acoustic resonator includes: a substrate; a resonant portion including a center portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on the substrate, and an extension portion disposed along a periphery of the center portion; and a first metal layer disposed outwardly of the resonant portion to be electrically connected to the first electrode. The extension portion includes a lower insertion layer disposed on an upper surface of the first electrode or a lower surface of the first electrode. The piezoelectric layer includes a piezoelectric portion disposed in the center portion, and a bent portion disposed in the extension portion and extended from the piezoelectric portion at an incline according to a shape of the lower insertion layer. The lower insertion layer is formed of a conductive material extending an electrical path between the first electrode and the first metal layer.

Description

Acoustic wave resonator and its manufacturing method

The following description relates to an acoustic wave resonator and its manufacturing method.

As wireless communication devices become more and more compact, there is an increasing demand for miniaturization of high-frequency components. As an example, the filter is provided in the form of a bulk acoustic wave (BAW) resonator using semiconductor thin film wafer manufacturing technology.

A bulk acoustic wave (BAW) resonator is a filter implemented using a thin film device that uses piezoelectric characteristics obtained by depositing a piezoelectric dielectric material on a silicon wafer as a semiconductor substrate to cause resonance.

Examples of applications of bulk acoustic wave (BAW) resonators include mobile communication devices, compact and lightweight filters for chemical and biological devices, oscillators, resonance elements, acoustic resonance quality sensors, and the like.

Various structural shapes and functions are being studied to enhance the characteristics and performance of bulk acoustic wave resonators. Therefore, the manufacturing method of the bulk acoustic wave resonator is constantly being studied.

The summary of the present invention is provided to introduce the selected concept in a simplified form, and the selected concept is further described in the following specific embodiments. This summary is neither intended to limit the key features or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

In a general aspect, an acoustic wave resonator includes: a substrate; a resonance portion including a central portion on which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on the substrate and disposed along an outer periphery of the central portion And a first metal layer disposed outside the resonant part to be electrically connected to the first electrode. The extension portion includes a lower insertion layer provided on the upper surface of the first electrode or the lower surface of the first electrode. The piezoelectric layer includes a piezoelectric portion and a bent portion, the piezoelectric portion is provided in the central portion, the bent portion is provided in the extension portion and is obliquely removed according to the shape of the lower insertion layer. The piezoelectric portion extends. The lower insertion layer is formed of a conductive material to extend the electrical path between the first electrode and the first metal layer.

The acoustic wave resonator may further include: a second metal layer disposed outside the resonance part to be electrically connected to the second electrode; and an upper insertion layer disposed in the extension part and disposed in the On the upper surface or the lower surface of the second electrode, and extend the electrical path between the second electrode and the second metal layer.

The second electrode may be spaced apart from the second metal layer, and the second electrode may be electrically connected to the second metal layer through the upper insertion layer.

The acoustic wave resonator may further include: a third electrode disposed on the same plane as the first electrode and spaced apart from the first electrode. The second electrode may be electrically connected to the third electrode through the second metal layer.

The upper insertion layer may be spaced apart from the boundary between the central part and the extension part. The extension portion may further include a first reflection area and a second reflection area, the first reflection area is disposed between the boundary and the upper insertion layer, and the second reflection area is disposed on the first reflection area. The outside of the area. The upper insertion layer and the second electrode may be provided together in the second reflection area.

The lower insertion layer may be formed using a material having an acoustic impedance lower than the acoustic impedance of the piezoelectric layer and the acoustic impedance of the first electrode.

The piezoelectric layer may be formed using aluminum nitride (AlN). The first electrode may be formed using molybdenum (Mo). The lower insertion layer may be formed using aluminum (Al) or aluminum (Al) alloy.

The lower insertion layer may be spaced apart from the boundary of the central part. The extension portion may further include a first reflection area and a second reflection area, the first reflection area is disposed between the boundary and the lower insertion layer, and the second reflection area is disposed on the first reflection area. The outside of the area. The lower insertion layer and the second electrode may be disposed together in the second reflection area.

The acoustic impedance of the second reflection area may be lower than the acoustic impedance of the first reflection area.

The acoustic wave resonator may further include: an insulating insertion layer disposed between the lower insertion layer and the piezoelectric layer and causing the bending portion to bulge.

The thickness of the extension part may be greater than the thickness of the central part.

In another general aspect, an acoustic wave resonator includes: a substrate; a resonance portion including a central portion on which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on the substrate, and an outer periphery along the central portion And a lower insertion layer, which is provided in the extension and is provided on the upper surface of the first electrode or the lower surface of the first electrode. The lower insertion layer is spaced apart from the boundary between the central part and the extension part. The extension portion includes a first reflection area and a second reflection area, the first reflection area is disposed between the boundary and the lower insertion layer, and the lower insertion layer and the second electrode are disposed together The second reflection area.

The piezoelectric layer may include a piezoelectric portion provided in the central portion and an inclined portion, the inclined portion being provided in the extension portion and obliquely from the lower insertion layer according to the shape of the lower insertion layer. The piezoelectric part extends. The first reflection area and the second reflection area may be provided in a range where the inclined portion is provided.

The lower insertion layer may be formed using a conductive material.

The inclination angle of the inclined portion may be in the range of 5° to 70°.

In another general aspect, a method of manufacturing an acoustic wave resonator includes: by stacking a first electrode, a piezoelectric layer, and a second electrode on a substrate, and on the upper surface of the first electrode or the lower surface of the first electrode A lower insertion layer including a conductive material is formed to form a resonance part; and after forming the resonance part, a first metal layer is formed on the lower insertion layer.

The resonance part may include a central part in which the first electrode, the piezoelectric layer, and the second electrode are sequentially stacked on the substrate, and an extension part provided along an outer periphery of the central part. The lower insertion layer may be provided in the extension part and spaced a predetermined distance from the boundary between the central part and the extension part.

The extension portion may include a first reflection area and a second reflection area, the first reflection area is disposed between the boundary and the lower insertion layer, and the second reflection area is disposed in the first reflection area And the lower insertion layer and the second electrode are disposed in the second reflection area together.

Other features and aspects will be apparent through the following specific embodiments, drawings and the scope of patent applications.

The following specific implementations are provided to help readers gain a comprehensive understanding of the methods, devices, and/or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and/or systems described herein will be obvious. For example, the order of operations described herein is only an example, and is not limited to the order set forth herein, but in addition to operations that must occur in a specific order, changes that will be obvious after understanding the disclosure of this application can be made. In addition, for greater clarity and conciseness, descriptions of features known in the art may be omitted.

The features described herein may be implemented in different forms and will not be construed as being limited to the examples described herein. More precisely, the examples described herein have been provided to illustrate some of the many possible ways of implementing the methods, devices and/or systems described herein that will be obvious after understanding the disclosure of this application. .

Here, it is noted that the use of the term "may" in relation to an example or embodiment (for example, in relation to what the example or embodiment may include or achieve) means that there is at least one example or embodiment that includes or implements such a feature, However, all examples and embodiments are not limited to this.

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, the element may be directly "on" another element. "The other element is "on", directly "connected to" the other element, or directly "coupled to" the other element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on", "directly connected to" or "directly coupled to" another element, there may be no other elements in between. .

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

Although terms such as "first", "second" and "third" may be used herein to describe various members, components, regions, layers or sections, these members, components, regions, layers or sections will not be affected by these Term limitation. More precisely, these terms are only used to distinguish one member, component, region, layer or section from another member, component, region, layer or section. Therefore, without departing from the teaching of the examples, the first member, the first component, the first region, the first layer, or the first part mentioned in the examples described herein may also be referred to as the second member, the second Component, second area, second layer or second part.

For ease of description, spatially relative terms such as "above", "above", "below", and "below" may be used herein to describe the relationship between one element and another element as shown in the drawings. Such spatial relative terms are intended to include the different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawing is turned over, an element described as being "above" or "above" another element will then be "below" or "below" the other element. Therefore, the term "above" includes two orientations of "above" and "below" according to the spatial orientation of the device. The device can also be positioned in other ways (for example, rotated by 90 degrees or in other orientations), and the spatial relative terms used herein will be explained accordingly.

The terms used here are only used to describe various examples, and will not be used to limit the present disclosure. Unless the context clearly dictates otherwise, the singular form is also intended to include the plural form. The terms "comprising", "including" and "having" enumerate the presence of stated features, quantities, operations, members, elements and/or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations , Components, elements and/or their combinations.

Due to manufacturing technology and/or tolerances, changes in the shape shown in the drawings may occur. Therefore, the examples described here are not limited to the specific shapes shown in the drawings, but include changes in shapes that occur during manufacturing.

The features of the examples described herein can be combined in various ways as will be apparent after understanding the disclosure of this application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of this application.

FIG. 1 is a plan view showing an acoustic wave resonator 100 according to an example. Fig. 2 is a cross-sectional view taken along the line I-I' of Fig. 1.

1 and 2, the acoustic wave resonator 100 according to an example may be a bulk acoustic wave (BAW) resonator, and may include a substrate 110, a sacrificial layer 140, a resonance part 120 and an insertion layer 170.

The substrate 110 may be a silicon substrate. For example, the substrate 110 may be a silicon wafer or a silicon-on-insulator (SOI) substrate.

The insulating layer 115 may be disposed on the upper surface of the substrate 110 to electrically isolate the substrate 110 and the resonance part 120 from each other. In addition, when the cavity C is formed during the manufacture of the acoustic wave resonator 100, the insulating layer 115 may prevent the substrate 110 from being etched by the etching gas.

In this example, the insulating layer 115 may use any one or any two of silicon dioxide (SiO ₂ ), silicon nitride (Si ₃ N ₄ ), aluminum oxide (Al ₂ O ₃ ), and aluminum nitride (AlN). One or more of any combination is formed, and can be formed on the substrate 110 by a process such as chemical vapor deposition, radio frequency (RF) magnetron sputtering, or evaporation.

The sacrificial layer 140 is formed on the insulating layer 115, and the cavity C and the etch stop 145 may be disposed in the sacrificial layer 140.

The cavity C is formed as an empty space, and may be formed by removing a part of the sacrificial layer 140.

Since the cavity C is formed in the sacrificial layer 140, all of the resonance part 120 formed above the sacrificial layer 140 may be formed to be flat.

The etching stop 145 is provided along the boundary of the cavity C. The etching stop part 145 is provided to prevent the etching from continuing to an area outside the cavity area during the formation of the cavity C. Therefore, the horizontal area of the cavity C is defined by the etch stop 145 and the vertical area (for example, height) of the cavity C is defined by the thickness of the sacrificial layer 140.

The film layer 150 is formed on the sacrificial layer 140 and forms the upper surface of the cavity C. Therefore, the film layer 150 is also formed of a material that is not easily removed during the process for forming the cavity C.

For example, when a halogen-based (such as fluorine (F), chlorine (Cl), etc.) etching gas is used to remove a part of the sacrificial layer 140 (for example, the cavity area), the film layer 150 may utilize a low-reactivity with the etching gas. Material formation. In this case, the film layer 150 may include any one or both of silicon dioxide (SiO ₂ ) and silicon nitride (Si ₃ N ₄ ).

In addition, the film layer 150 may include magnesium oxide (MgO), zirconium oxide (ZrO ₂ ), aluminum nitride (AlN), lead zirconate titanate (PZT), gallium arsenide (GaAs), hafnium oxide (HfO ₂ ), A dielectric layer of any one of aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), and zinc oxide (ZnO) or any combination of any two or more, or may include a dielectric layer containing aluminum (Al), A metal layer of any one of nickel (Ni), chromium (Cr), platinum (Pt), gallium (Ga), and hafnium (Hf) or any combination of any two or more. However, the configuration of the film layer is not limited to the above example.

A seed layer (not shown) that may be formed of aluminum nitride (AlN) may be formed on the film layer 150. In detail, the seed layer may be disposed between the film layer 150 and the first electrode 121. In addition to AlN, the seed layer can also be formed using a dielectric or metal having a hexagonal closest packing (HCP) structure. For example, in an example where the seed layer is formed using metal, the seed layer may be formed using titanium (Ti).

The resonance part 120 includes a first electrode 121, a piezoelectric layer 123 and a second electrode 125. In the resonance part 120, the first electrode 121, the piezoelectric layer 123, and the second electrode 125 are stacked from the bottom to the top. Therefore, in the resonance part 120, the piezoelectric layer 123 is provided between the first electrode 121 and the second electrode 125.

The resonant part 120 is formed on the film layer 150. As a result, the film layer 150, the first electrode 121, the piezoelectric layer 123, and the second electrode 125 are sequentially stacked on the substrate 110 to form the resonance part 120.

The resonant part 120 may resonate the piezoelectric layer 123 according to the signal applied to the first electrode 121 and the second electrode 125 to generate a resonant frequency and an anti-resonant frequency.

The resonance part 120 may include a central part S and an extension part E. In the central part S, the first electrode 121, the piezoelectric layer 123, and the second electrode 125 are sequentially stacked, and in the extension part E, the insertion layer 170 is interposed between the first Between the electrode 121, the piezoelectric layer 123 and the second electrode 125.

The central portion S is an area provided in the center of the resonance portion 120, and the extension portion E is an area provided along the outer periphery of the central portion S. Therefore, the extension portion E refers to an area extending outward from the central portion S.

The insertion layer 170 has an inclined surface L, and the thickness of the inclined surface L becomes larger as the distance from the central portion S increases. In the extension E, a part of the piezoelectric layer 123 and a part of the second electrode 125 are provided on the insertion layer 170. Therefore, in the extension E, the piezoelectric layer 123 and the second electrode 125 have inclined surfaces formed according to the shape of the inclined surface L of the insertion layer 170.

In the example of FIGS. 1 and 2, the extension part E is included in the resonance part 120, so even in the extension part E, resonance may occur. However, the present disclosure is not limited to this example, and depending on the structure of the extension part E, resonance may not occur in the extension part E but may occur in the central part S.

The first electrode 121 and the second electrode 125 may use conductors (for example, gold, molybdenum, ruthenium, iridium, aluminum, platinum, titanium, tungsten, palladium, tantalum, chromium, nickel, or include gold, molybdenum, ruthenium, iridium, aluminum, Any one of platinum, titanium, tungsten, palladium, tantalum, chromium, and nickel or an alloy of any combination of any two or more). However, the first electrode 121 and the second electrode 125 are not limited to the aforementioned materials.

In the resonance part 120, the area of the first electrode 121 may be greater than the area of the second electrode 125, and the first metal layer 180 is disposed on the first electrode 121 along the outer edge of the first electrode 121. Therefore, the first metal layer 180 is spaced apart from the second electrode 125 by a predetermined distance, and the first metal layer 180 may be disposed to surround the resonance part 120.

Since the first electrode 121 is disposed on the film layer 150, the first electrode is completely flat. On the other hand, since the second electrode 125 is provided on the piezoelectric layer 123 and the upper insertion layer 170b, the second electrode may have a bent portion corresponding to the shape of the piezoelectric layer 123 and the upper insertion layer 170b in the extension E.

The second electrode 125 is provided throughout the entire central portion S, and is partially provided in the extension portion E. Therefore, the second electrode 125 may include a portion provided on the piezoelectric portion 123a (to be described later) of the piezoelectric layer 123, a portion provided on the bent portion 123b of the piezoelectric layer 123 in the extension E, and a portion provided The portion on the upper insertion layer 170b (to be described later) located in the extension E.

In addition, the portion of the second electrode 125 disposed on the inclined portion 1231 of the piezoelectric layer 123 may be formed to have an area smaller than that of the inclined surface of the inclined portion 1231.

The piezoelectric layer 123 is formed on the first electrode 121 and the lower insertion layer 170a (to be described later).

In the example of FIGS. 1 and 2, the piezoelectric layer 123 may be formed using aluminum nitride (AlN). However, the piezoelectric layer is not limited to being formed using AlN, and zinc oxide (ZnO), doped aluminum nitride, lead zirconate titanate, and quartz may be selectively used as the material of the piezoelectric layer 123. In an example in which the piezoelectric layer is formed using doped aluminum nitride, the piezoelectric layer may further 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). The transition metal may include any one or any combination of any two or more of hafnium (Hf), titanium (Ti), zirconium (Zr), tantalum (Ta), and niobium (Nb). In addition, the alkaline earth metal may include magnesium (Mg).

The piezoelectric layer 123 may include a piezoelectric part 123a provided in the central part S and a bent part 123b provided in the extension part E.

The piezoelectric part 123a is a part directly stacked on the upper surface of the first electrode 121. Therefore, the piezoelectric portion 123a is interposed between the first electrode 121 and the second electrode 125, and is provided to be flat together with the first electrode 121 and the second electrode 125.

The bent portion 123b may be defined as an area extending outward from the piezoelectric portion 123a and located within the extension portion E, the area being swelled due to the lower insertion layer 170a (to be described later).

Therefore, the bent portion 123b is provided on the lower insertion layer 170a (to be described later), and may be formed to have a shape bent according to the shape of the lower insertion layer 170a. Therefore, the piezoelectric layer 123 is curved at the boundary between the piezoelectric portion 123a and the curved portion 123b, and the curved portion 123b is raised to correspond to the thickness and shape of the lower insertion layer 170a.

The curved portion 123b may include an inclined portion 1231 and an extension portion 1232.

The inclined portion 1231 is a portion formed to be inclined due to the inclined surface L of the lower insertion layer 170a (to be described later). In addition, the extension portion 1232 is a portion extending outward from the inclined portion 1231.

The upper surface of the inclined portion 1231 may be formed to be arranged in parallel with the inclined surface L of the lower insertion layer 170a, and therefore, the inclined angle of the inclined portion 1231 may be equal to the inclined angle θ of the inclined surface L of the lower insertion layer 170a.

The insertion layer 170 is provided around the central part S and is provided under the second electrode 125.

Therefore, the insertion layer 170 is provided in all areas other than the central portion S or some areas other than the central portion S.

The insertion layer 170 is formed using a metal material, and may include a lower insertion layer 170a and an upper insertion layer 170b spaced apart from each other. Therefore, in the following description, references to the insertion layer 170 include both the lower insertion layer 170a and the upper insertion layer 170b.

In this example, all of the lower insertion layer 170 a is disposed on the first electrode 121. However, the present disclosure is not limited to such a configuration, and the lower insertion layer 170a may extend to the outside of the first electrode 121 if necessary. In such an example, the lower insertion layer 170a may be provided on the surface of the film layer 150 and the etching stop part 145.

The lower insertion layer 170 a is provided in a region of the outer periphery of the central portion S where the upper insertion layer 170 b is not provided to support the bent portion 123 b of the piezoelectric layer 123. Therefore, at least a part of the lower insertion layer 170 a is disposed between the piezoelectric layer 123 and the first electrode 121.

According to the shape of the lower insertion layer 170a, the bent portion 123b of the piezoelectric layer 123 may include an inclined portion 1231 and an extension portion 1232.

In addition, the lower insertion layer 170a is disposed between the first electrode 121 and the first metal layer 180. Therefore, the lower insertion layer 170a makes the electrical path between the first electrode 121 and the first metal layer 180 extend in a part of the extension E. This configuration can reduce the wiring resistance of the first electrode 121 in the extension E or in the vicinity of the extension E. Therefore, the insertion loss of the acoustic wave resonator can be reduced.

The upper insertion layer 170b is disposed between the second electrode 125 and the piezoelectric layer 123, and may be disposed in contact with a portion of the second electrode 125 disposed in the extension E.

In the illustrated example, the upper insertion layer 170b is formed on the piezoelectric layer 123, and the second electrode 125 is stacked and disposed on the upper surface of the upper insertion layer 170b. However, the present disclosure is not limited to this configuration, and if necessary, the upper insertion layer 170b may be stacked and disposed between the second electrode 125 and the protective layer 127.

In addition, one side of the upper insertion layer 170b is connected to the second metal layer 190. Therefore, the upper insertion layer 170b causes the electrical path between the second electrode 125 and the second metal layer 190 to extend in a part of the extension E. This configuration can reduce the wiring resistance of the second electrode 125 in the extension E or in the vicinity of the extension E. Therefore, the insertion loss of the acoustic wave resonator 100 can be reduced.

The insertion layer 170 configured as described above is formed to have a thickness that becomes larger as the distance from the central portion S increases. Therefore, the insertion layer 170 has a side surface disposed adjacent to the central portion S as an inclined surface L having a constant inclination angle θ.

In order to manufacture a configuration in which the inclination angle θ of the side surface of the insertion layer 170 is formed to be less than 5°, the thickness of the insertion layer 170 needs to be very small or the area of the inclined surface L of the insertion layer 170 needs to be very large. Therefore, it is difficult to realize the insertion layer 170 to have an inclination angle θ of less than 5°.

In addition, if the inclination angle θ of the side surface of the insertion layer 170 is formed to be greater than 70°, the inclination angle of the piezoelectric layer 123 stacked on the insertion layer 170 or the inclination angle of the second electrode 125 is also formed to be greater than 70°. In this case, the piezoelectric layer 123 or the second electrode 125 stacked on the inclined surface L is excessively bent, and thus cracks may occur in the bent portion.

Therefore, in the example of FIGS. 1 and 2, the inclination angle θ of the inclined surface L is formed to be in a range of greater than or equal to 5° to less than or equal to 70°.

In the example of FIGS. 1 and 2, the inclined portion 1231 of the piezoelectric layer 123 is formed along the inclined surface L of the insertion layer 170 and is thus formed to have an inclination angle equal to that of the inclined surface L of the insertion layer 170. Therefore, the inclination angle of the inclined portion 1231 is formed in a range of greater than or equal to 5° to less than or equal to 70° in a manner similar to that of the inclined surface L of the insertion layer 170. This configuration is also applicable to the second electrode 125 stacked on the inclined surface L of the insertion layer 170.

In addition, the inclination angle of the lower insertion layer 170a and the inclination angle of the upper insertion layer 170b may be different from each other. However, the inclination angle of the lower insertion layer 170a and the inclination angle of the upper insertion layer 170b are formed to be included in the above range.

The lower insertion layer 170a is formed using a material having an acoustic impedance lower than that of other components disposed adjacent to the lower insertion layer 170a. In detail, the lower insertion layer 170 a is formed using a material having an acoustic impedance lower than the acoustic impedance of the piezoelectric layer 123 and the acoustic impedance of the first electrode 121 and the acoustic impedance of the second electrode 125.

For example, in the acoustic wave resonator according to this example, in order to achieve a resonance frequency of 4.9 GHz, the second electrode 125 is formed with molybdenum (Mo) with a thickness of 1000 Å, and the piezoelectric layer 123 is formed with aluminum nitride (with a thickness of 4000 Å). AlN) is formed, and the first electrode 121 is formed with molybdenum (Mo) with a thickness of 1200 Å.

In this example, the lower insertion layer 170 a combined with the first electrode 121 needs to be formed with a material having low resistance and lower acoustic impedance than the material of the piezoelectric layer 123 or the material of the first electrode 121. Advantageously, the material may be aluminum (Al) or aluminum (Al)-based material, and the thickness may be configured to be in the range of about 1000 Å to about 6000 Å. However, the present disclosure is not limited to this example.

The upper insertion layer 170b may be formed using the same material as that of the lower insertion layer 170a. In addition, the upper insertion layer 170 may be formed using molybdenum (Mo), ruthenium (Ru), gold (Au), platinum (Pt), etc., which have low resistance. The thickness of the upper insertion layer 170b may be formed in the range of about 1000 Å to about 6000 Å in a similar manner to that of the lower insertion layer 170a.

The resonant part 120 is spaced apart from the substrate 110 by the cavity C which is an empty space.

The cavity C may be formed by supplying an etching gas (or etchant) to the introduction hole (H in FIG. 1) to remove a part of the sacrificial layer 140 during the process of manufacturing the acoustic resonator 100.

The protective layer 127 is provided along the surface of the acoustic wave resonator 100 to protect the acoustic wave resonator 100 from external factors. The protective layer 127 may be provided along the surface formed by the second electrode 125 and the bent portion 123 b of the piezoelectric layer 123.

The protective layer 127 may be formed of an insulating material including any one or any combination of any two or more of silicon oxide-based materials, silicon nitride-based materials, aluminum oxide-based materials, and aluminum nitride-based materials, but is not limited to this.

The protective layer 127 may include a single layer. Alternatively, if necessary, two layers formed using different materials may be stacked to form the protective layer 127.

The first electrode 121 and the second electrode 125 may extend to the outside of the resonance part 120. In addition, as described above, the first metal layer 180 may be provided on the upper surface of the extension portion of the first electrode 121, and the second metal layer 190 may be provided on the upper surface of the extension portion of the second electrode 125.

The first metal layer 180 and the second metal layer 190 may be formed using materials such as gold (Au), gold-tin (Au-Sn) alloy, copper (Cu), copper-tin (Cu-Sn) alloy, and the like.

The first metal layer 180 and the second metal layer 190 may be used as connection wirings that electrically connect the electrodes 121 and 125 to the electrodes of another acoustic wave resonator disposed adjacent to the electrodes 121 and 125 on the substrate 110. Optionally, the first metal layer 180 and the second metal layer 190 may be used as terminals for external connection. However, the present disclosure is not limited to the foregoing examples. 2, the second metal layer 190 may connect the second electrode 125 provided on the upper insertion layer 170b and the third electrode 129 provided under the piezoelectric layer 123 to each other. The third electrode 129 is an electrode manufactured together with the first electrode 121, and may be formed using the same material as that of the first electrode 121, and may be disposed on the same plane as the first electrode 121. The third electrode 129 may be connected to a first electrode or a second electrode of another acoustic wave resonator (not shown) provided adjacent to the third electrode 129 on the substrate 110.

The first metal layer 180 passes through the protective layer 127 to be coupled to the first electrode 121.

In addition, in the resonance part 120, the area of the first electrode 121 is larger than the area of the second electrode 125, and the first metal layer 180 is formed in the outer peripheral portion of the first electrode 121.

Therefore, the first metal layer 180 is provided along the outer circumference of the resonance part 120 and is provided to surround the second electrode 125. However, the present disclosure is not limited to such a configuration.

Due to the insertion layer 170, the extension part E of the resonance part 120 is formed to have a thickness greater than the thickness of the central part S. Therefore, the vibration generated in the central portion S is suppressed from flowing to the outer edge, thereby increasing the Q factor of the acoustic wave resonator 100.

In addition, the second electrode 125 is partially disposed in the extension E, thereby providing a significantly improved resonance performance.

In addition, the insertion layer 170 is formed using a metal material (or a conductive material), and is provided in the boundary portion of the central portion S (ie, the effective region) of the acoustic wave resonator 100. Therefore, in the boundary portion of the central portion S, the electrical path of the first electrode 121 or the electrical path of the second electrode 125 is extended. In this regard, the wiring resistance of the first electrode 121 and the wiring resistance of the second electrode 125 are reduced, so that the insertion loss of the acoustic wave resonator 100 is reduced.

In addition, compared with the acoustic resonator according to the related art (in which the insertion layer 170 is formed using an insulating material), when the insertion layer 170 is formed using a metal material (as in the example of FIGS. 1 and 2), the measured temperature The change is small, 13.4%. In this regard, it is confirmed that the heat dissipation characteristics are relatively excellent.

Next, a method of manufacturing the acoustic wave resonator 100 will be described.

3 to 6 are diagrams illustrating a method of manufacturing the acoustic wave resonator 100 according to an example.

First, referring to FIG. 3, in the method of manufacturing the acoustic wave resonator 100, the insulating layer 115 and the sacrificial layer 140 are first formed on the substrate 110, and then the pattern P passing through the sacrificial layer 140 is provided. Therefore, the insulating layer 115 is exposed to the outside through the pattern P.

The insulating layer 115 may use magnesium oxide (MgO), zirconium oxide (ZrO ₂ ), aluminum nitride (AlN), lead zirconate titanate (PZT), gallium arsenide (GaAs), hafnium oxide (HfO ₂ ), aluminum oxide ( Al ₂ O ₃ ), titanium oxide (TiO ₂ ), zinc oxide (ZnO), silicon nitride (SiN), or silicon dioxide (SiO ₂ ) are formed, but not limited thereto.

The pattern P formed in the sacrificial layer 140 is formed to have inclined side surfaces. In this regard, it is possible to prevent an abrupt step from being generated at the boundary between the etching stop part 145 and the sacrificial layer 140 to be formed in the pattern P later. In addition, the pattern P may be formed to have a cross section in the form of a trapezoid in which the width of the upper surface is wider than the width of the lower surface. In this respect, the occurrence of dishing can be prevented. For example, the angle formed by the lower surface and the side surface of the cross section of the pattern P may be 110° to 160°, and the width of the lower surface may be 2 μm to 30 μm.

A part of the sacrificial layer 140 is removed by a subsequent etching process to form a cavity C (FIG. 2 ). Therefore, the sacrificial layer 140 may be formed using a material that can be easily etched, such as polysilicon or polymer. However, the present disclosure is not limited to such an example.

Then, a film layer 150 is formed on the sacrificial layer 140. The film layer 150 is formed to have a constant thickness along the surface of the sacrificial layer 140. The thickness of the film layer 150 may be less than the thickness of the sacrificial layer 140.

The film layer 150 may include any one or both of silicon dioxide (SiO ₂ ) and silicon nitride (Si ₃ N ₄ ). In addition, the film layer 150 may include magnesium oxide (MgO), zirconium oxide (ZrO ₂ ), aluminum nitride (AlN), lead zirconate titanate (PZT), gallium arsenide (GaAs), hafnium oxide (HfO ₂ ), A dielectric layer of any one of aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), and zinc oxide (ZnO) or any combination of any two or more, or may include a dielectric layer containing aluminum (Al), A metal layer of any one of nickel (Ni), chromium (Cr), platinum (Pt), gallium (Ga), and hafnium (Hf) or any combination of any two or more. However, the film layer 150 is not limited to the exemplary configuration.

Although not shown, a seed layer may be formed on the film layer 150. The seed layer may be disposed between the film layer 150 and the first electrode 121 (to be described later). The seed layer may be formed using aluminum nitride (AlN), but is not limited thereto. Alternatively, a dielectric or metal having an HCP structure may be used to form the seed layer. For example, when the seed layer is formed using metal, the seed layer may be formed using titanium (Ti).

Then, an etch stop layer 145a is formed on the film layer 150. The etch stop layer 145a is filled inside the pattern P.

The etch stop layer 145a is formed to have a thickness that completely fills the pattern P. Therefore, the etch stop layer 145a may be formed thicker than the sacrificial layer 140.

The etch stop layer 145a may be formed using the same material as that of the insulating layer 115, but is not limited thereto.

Then, the etch stop layer 145a is removed so that the film layer 150 is exposed to the outside.

In this example, the portion of the etch stop layer filled in the inside of the pattern P is retained, and the retained portion of the etch stop layer 145a may be used as the etch stop portion 145.

Then, the first electrode 121 and the third electrode 129 are formed on the upper surface of the film layer 150.

The first electrode 121 and the third electrode 129 may use conductors (for example, gold, molybdenum, ruthenium, iridium, aluminum, platinum, titanium, tungsten, palladium, tantalum, chromium, nickel or include gold, molybdenum, ruthenium, iridium, aluminum, Any one of platinum, titanium, tungsten, palladium, tantalum, chromium, and nickel or an alloy of any combination of any two or more) is formed, but not limited thereto.

The first electrode 121 may be formed on the upper part of the region where the cavity C (FIG. 2) will be formed.

For example, the first electrode 121 and the third electrode 129 are simultaneously formed by removing unnecessary portions of the conductor layer after the conductor layer is provided to cover the entire film layer 150.

Next, as shown in FIG. 4, a lower insertion layer 170a is provided. The lower insertion layer 170 a is formed on the first electrode 121, and if necessary, the lower insertion layer 170 a may extend to the upper portion of the film layer 150.

After the conductive material is deposited to cover the entire surface formed by the film layer 150, the first electrode 121 and the etch stop 145, the lower insertion layer 170a may be completed by a patterning process for removing unnecessary portions of the conductive material.

Therefore, the lower insertion layer 170a is not provided on the central portion S (FIG. 2). In the examples of FIGS. 3 to 6, all of the lower insertion layer 170 a is disposed on the first electrode 121. However, the present disclosure is not limited to the example structure of the lower insertion layer 170a. When the shape of the first electrode 121 is changed, at least a part of the lower insertion layer 170a may be stacked on the film layer 150 or the etch stop 145.

The side surface of the lower insertion layer 170a disposed adjacent to the central portion S is formed as an inclined surface L (FIG. 2 ). The lower insertion layer 170a has an inclined surface L whose thickness decreases toward the central portion S, and therefore, the lower surface of the lower insertion layer 170a further extends toward the central portion S compared to the upper surface of the lower insertion layer 170a. As previously described, the inclination angle of the inclined surface L of the lower insertion layer 170a may be in the range of 5° to 70°.

The lower insertion layer 170 a is formed using a metal material, and may be formed using a material having an acoustic impedance lower than that of the piezoelectric layer 123 and the acoustic impedance of the first electrode 121. As described above, when the piezoelectric layer 123 is formed using aluminum nitride (AlN), the lower insertion layer 170a may be formed using aluminum or an aluminum alloy material.

Then, the piezoelectric layer 123 is formed on the first electrode 121 and the lower insertion layer 170a. The piezoelectric layer 123 may be formed using aluminum nitride (AlN), but is not limited thereto. Zinc oxide (ZnO), doped aluminum nitride, lead zirconate titanate, quartz, etc. may be selectively used for the piezoelectric layer 123. When the piezoelectric layer 123 is formed using doped aluminum nitride, the piezoelectric layer 123 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). The transition metal may include any one or any combination of any two or more of hafnium (Hf), titanium (Ti), zirconium (Zr), tantalum (Ta), and niobium (Nb). In addition, the alkaline earth metal may include magnesium (Mg).

The piezoelectric layer 123 may be formed by partially removing unnecessary portions of the piezoelectric material after the piezoelectric material is formed on the entire surface formed by the first electrode 121, the lower insertion layer 170a, and the like. In the example of FIGS. 3 to 6, the piezoelectric layer 123 is completed by removing unnecessary portions of the piezoelectric material and unnecessary portions of the preliminary second electrode 125' after the preliminary second electrode 125' is formed. However, alternatively, the piezoelectric layer 123 may be completed by removing unnecessary portions of the piezoelectric material before forming the preliminary second electrode 125'.

The piezoelectric layer 123 is stacked on the first electrode 121 and the lower insertion layer 170a, and may be formed according to the shape of the surface formed by the first electrode 121 and the lower insertion layer 170a.

As shown in FIG. 2, a portion of the piezoelectric layer 123 stacked on the first electrode 121 forms a piezoelectric portion 123a, and a portion of the piezoelectric layer 123 stacked on the lower insertion layer 170a forms a bent portion 123b.

Then, an upper insertion layer 170b is formed on the piezoelectric layer 123. The upper insertion layer 170b may be formed using the same material as that of the lower insertion layer 170a. In this case, the upper insertion layer 170b may be provided using the same formation method as that of the lower insertion layer 170a. However, the present disclosure is not limited to the foregoing configuration.

Then, a preliminary second electrode 125' is formed on the upper surface of the piezoelectric layer 123 and the upper surface of the upper insertion layer 170b. The preliminary second electrode 125' may use a conductor (for example, gold, molybdenum, ruthenium, iridium, aluminum, platinum, titanium, tungsten, palladium, tantalum, chromium, nickel or include gold, molybdenum, ruthenium, iridium, aluminum, platinum, Titanium, tungsten, palladium, tantalum, chromium, nickel, or any combination of any two or more alloys), but not limited thereto.

The second electrode 125 may be shown in FIG. 5 by using a method such as etching to remove unnecessary portions of the conductive layer after forming a conductive layer on the entire surface formed by the piezoelectric layer 123 and the upper insertion layer 170b. form. During the above process, a process for removing unnecessary parts of the piezoelectric layer 123 may be performed.

Then, a protective layer 127 is provided.

The protective layer 127 may be formed along the surface formed by the second electrode 125, the piezoelectric layer 123, and the upper insertion layer 170b.

The protective layer 127 may be formed of an insulating material including any one or any combination of any two or more of silicon oxide-based materials, silicon nitride-based materials, aluminum oxide-based materials, and aluminum nitride-based materials, but is not limited to this.

Next, as shown in FIGS. 5 and 6, the protective layer 127 is partially removed to partially expose the first electrode 121 and the second electrode 125, and the first metal layer 180 and the second metal layer are formed in the exposed portions, respectively. Layer 190 to complete the acoustic wave resonator 100 shown in FIG. 2.

During the process for removing the protective layer 127, not only the first electrode 121 and the second electrode 125 are partially exposed, but also the lower insertion layer 170a, the upper insertion layer 170b, and the third electrode 129 are also partially exposed. Therefore, the first metal layer 180 is formed on the first electrode 121 and the lower insertion layer 170a to be electrically connected to each other, and the second metal layer 190 is formed on the second electrode 125, the upper insertion layer 170b, and the third electrode 129 to be electrically connected to each other. connection.

The first metal layer 180 and the second metal layer 190 may be formed using materials such as gold (Au), gold-tin (Au-Sn) alloy, copper (Cu), copper-tin (Cu-Sn) alloy, etc., and may It is formed using a method such as deposition, but is not limited thereto.

Then, cavity C is formed. The cavity C is formed by removing the portion of the sacrificial layer located inside the etching stop 145, thereby completing the acoustic wave resonator 100 shown in FIG. 2. The portion of the sacrificial layer 140 may be removed by supplying an etching gas (or etchant) to the introduction hole H (FIG. 1 ).

When the sacrificial layer 140 is formed using a material such as polysilicon or polymer, it can be dried by using a halogen-based (such as fluorine (F), chlorine (Cl), etc.) etching gas (for example, xenon difluoride (XeF ₂ )). The sacrificial layer 140 is removed by etching.

The present disclosure is not limited to the above examples and can be modified in various ways.

FIG. 7 is a schematic cross-sectional view showing an acoustic wave resonator 200 including a resonance part 220 according to another example.

7, in the acoustic wave resonator 200, the upper insertion layer 270b is provided between the second electrode 225 and the protective layer 227. In more detail, the upper insertion layer 270b is formed on the upper surface of the second electrode 225, and the protective layer 227 is formed on the upper surface of the upper insertion layer 270b.

The acoustic wave resonator 200 may be manufactured by stacking the insertion layer 270b on the second electrode 225 after the second electrode 225 is completed.

FIG. 8 is a schematic cross-sectional view showing an acoustic wave resonator 300 according to another example. FIG. 9 is an enlarged view of the upper insertion layer 370b of FIG. 8.

8 and 9, in the acoustic wave resonator 300, the second electrode 325 is provided in all of the central portion S, and is provided in a part of the extension portion E, and may not be provided outside the extension portion E.

Therefore, the edge of the second electrode 325 provided in the extension E is located on the inclined surface L of the piezoelectric layer 123 or the inclined surface of the upper insertion layer 370b.

Since the second electrode 325 is only provided in the resonance part 320, the second electrode 325 is spaced apart from the second metal layer 190, so that the second electrode 325 is electrically connected to the second metal layer 190 through the upper insertion layer 370b. A protective layer 327 is formed on the upper surface of the upper insertion layer 370b.

In addition, referring to FIG. 9, the upper insertion layer 370b is spaced apart from the vertical interface R of the central portion S by a predetermined distance W1.

The extension E includes a first reflection area (hereinafter referred to as W1 area) and a second reflection area (hereinafter referred to as W2 area). The first reflection area is located between the vertical interface R of the central portion S and the upper insertion layer 370b The second reflection area is located outside the first reflection area and is defined as the area in which the upper insertion layer 370b and the second electrode 325 are disposed together.

The portion of the second electrode 325 provided on the upper insertion layer 370b may be provided only in some regions of the inclined surface L of the upper insertion layer 370b.

In this example, the upper insertion layer 370b is not provided in the W1 area. However, in the W1 area, the second electrode 325 may swell due to the shape of the upper insertion layer 370b. Therefore, since the W1 area has a larger thickness than the central portion S, the acoustic impedance of the W1 area is further increased compared to the central portion S.

In addition, compared to the W1 area, the W2 area is an area that also includes the upper insertion layer 370b. In the W2 area, the upper insertion layer 370b is interposed between the second electrode 325 and the piezoelectric layer 123. Compared with the piezoelectric layer 123 or the second electrode 325, the upper insertion layer 370b is formed of a metal material with lower acoustic impedance. Therefore, compared to the W1 area, the W2 area has a lower acoustic impedance.

In this example, since the central portion S, the W1 area, and the W2 area have a sparse/dense/sparse structure, the reflection interface for reflecting the transverse wave to the inside of the resonance portion 320 increases. Therefore, most of the transverse waves cannot flow to the outside of the resonance part 320, but are reflected and then flow into the inside of the resonance part 320, thereby improving attenuation characteristics.

The large attenuation of the acoustic wave resonator 300 means that the loss that occurs due to the lateral wave flowing to the outside of the resonance part 320 is small. Therefore, the performance of the acoustic wave resonator 300 is improved.

When the distance W1 and the distance W2 are n/4 times the wavelength (λ) of the transverse wave, the reflection efficiency increases. In this regard, in order to increase the reflection efficiency, the width of the W1 area and the width of the W2 area can be adjusted in consideration of the wavelength of the transverse wave. n is a natural number, such as 1, 2, 3, etc.

The configuration shown in FIG. 9 is not limited to the example, and can be applied to other examples.

FIG. 10 is a schematic cross-sectional view showing an acoustic wave resonator 400 according to another example. Fig. 11 is an enlarged view of the lower insertion layer of Fig. 10.

The acoustic wave resonator shown in FIG. 10 is provided with only the lower insertion layer 170a. In addition, as shown in FIG. 11, the lower insertion layer 170a is spaced apart from the vertical interface R of the central portion S by a predetermined distance W1. In addition, the portion of the second electrode 425 provided on the inclined portion 1231 of the piezoelectric layer 123 is only provided on the portion of the inclined surface of the inclined portion 1231. The protective layer 427 is formed on the upper surface of the second electrode 425.

In addition, referring to FIG. 11, in a manner similar to the example of FIG. 8 and FIG. 9 described above, the lower insertion layer 170a is not provided in the W1 area, and in the W1 area, the second electrode 425 is based on the lower insertion layer 170a. Shape and bulge. Therefore, since the W1 area has a larger thickness than the central portion S, the acoustic impedance of the W1 area is further increased compared to the central portion S.

In addition, compared to the W1 area, the W2 area is an area that also includes the lower insertion layer 170a. In the W2 area, the lower insertion layer 170 a is interposed between the first electrode 121 and the piezoelectric layer 123. As mentioned above, compared to the piezoelectric layer 123 or the first electrode 121, the upper insertion layer 170b is formed of a metal material with a lower acoustic impedance. Therefore, compared to the W1 area, the W2 area has a lower acoustic impedance.

In a manner similar to the case of FIG. 9 described above, since the central portion S, the W1 region, and the W2 region have a sparse/dense/sparse structure, the reflection interface for reflecting the transverse wave to the inside of the resonance section 420 increases. Therefore, most of the transverse waves cannot flow to the outside of the resonance part 420, but are reflected and then flow into the inside of the resonance part 420, thereby improving attenuation characteristics.

The configuration of FIG. 11 is not limited to the above-mentioned example, and may be applied to other examples.

FIG. 12 is a schematic cross-sectional view showing an acoustic wave resonator 500 according to another example.

12, the acoustic wave resonator 500 includes an insulating insertion layer 171 and a lower insertion layer 172.

In this example, the insulating insertion layer 171 is provided so that the extension portion E is formed to have a thickness larger than that of the central portion S. In addition, the lower insertion layer 172 serves to extend the electrical path of the first electrode 521 or the electrical path of the second electrode 525 from the boundary portion of the central portion S (ie, the extension portion E).

A protective layer 527 is formed on the upper surface of the second electrode 525.

Therefore, the insulating insertion layer 171 may use materials such as silicon dioxide (SiO ₂ ), aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ ), silicon nitride (SiN), magnesium oxide (MgO), zirconia (ZrO) ₂ ) Dielectrics of lead zirconate titanate (PZT), gallium arsenide (GaAs), hafnium oxide (HfO ₂ ), titanium oxide (TiO ₂ ) or zinc oxide (ZnO) instead of conductive materials are formed to have a small sound However, it can also be formed using a material different from that of the piezoelectric layer 123.

The lower insertion layer 172 includes a first insertion layer 172 a disposed under the first electrode 521 and a second insertion layer 172 b disposed under the third electrode 529. Here, the second electrode 525 is not directly connected to the second insertion layer 172b, but is indirectly connected to the second insertion layer 172b through the second metal layer 190 and the third electrode 529. In this regard, the second insertion layer 172b extends the electrical path of the portion where the second metal layer 190 and the third electrode 529 are connected to each other.

The lower insertion layer 172 may include a metal material. For example, the lower insertion layer 172 may use gold, molybdenum, ruthenium, iridium, aluminum, platinum, titanium, tungsten, palladium, tantalum, chromium, nickel, or include gold, molybdenum, ruthenium, iridium, aluminum, platinum, titanium, tungsten, and palladium. , Tantalum, chromium, nickel, or any combination of any two or more, but not limited to this.

In the acoustic wave resonator 500, the lower insertion layer 172 is disposed farther away from the center of the resonance part 520 than the insulating insertion layer 171.

The lower insertion layer 172 may be disposed on the upper surface of the first electrode 521, that is, between the piezoelectric layer 123 and the insulating insertion layer 171.

In the acoustic wave resonator 500, when the horizontal distance between the insulating insertion layer 171 and the lower insertion layer 172 is adjusted, the reflection performance of the transverse wave generated at the anti-resonance point can be further improved, thereby additionally improving the attenuation performance.

In the acoustic wave resonator 500, the large attenuation of the acoustic wave resonator means that the loss that occurs due to the lateral wave flowing to the outside of the resonance part 520 is small. Therefore, this means that the performance of the acoustic wave resonator is improved.

FIG. 13 is a schematic cross-sectional view showing an acoustic wave resonator 600 according to another example.

In FIG. 13 which is a modified example of FIG. 12, the acoustic wave resonator 600 includes a resonance part 620, an insulating insertion layer 171, a lower insertion layer 172, and an upper insertion layer 173.

Since the insulating insertion layer 171 and the lower insertion layer 172 are configured in the same manner as in the example of FIG. 12, detailed descriptions thereof will be omitted.

The upper insertion layer 173 is stacked on the upper or lower portion of the second electrode 525 so as to extend the electrical path between the second electrode 525 and the second metal layer 190. Therefore, in this example, the electrical path of the second electrode 525 may extend at two locations due to the upper insertion layer 173 and the second insertion layer 172b.

The acoustic wave resonator 600 can be formed by sequentially stacking the lower insertion layer 172, the first electrode 521, the insulating insertion layer 171, the piezoelectric layer 123, the second electrode 525, the upper insertion layer 173, the protective layer 627, and the first electrode on the film layer 150. The metal layer 180 and the second metal layer 190 are manufactured.

As explained above, according to the embodiments disclosed herein, in the acoustic wave resonator, the insertion layer is formed of a conductive material and is disposed in the boundary portion of the resonance effective region of the acoustic wave resonator, so the electrical path or the second The electrical path of the two electrodes may extend in the boundary portion of the resonance effective region. Therefore, the wiring resistance of the first electrode and the wiring resistance of the second electrode can be reduced, thereby reducing the insertion loss of the acoustic wave resonator.

In addition, two reflection areas with different acoustic impedances are provided in the extension, thereby increasing the reflection efficiency of the transverse wave.

Although this disclosure includes specific examples, it will be obvious after understanding the disclosure of this application that without departing from the scope of the patent application and the spirit and scope of its equivalents, these examples can be made in terms of form and details. Various changes. The examples described here are considered to be descriptive and not for the purpose of limitation. Descriptions of features or aspects in each example will be considered applicable to similar features or aspects in other examples. If the described technology is performed in a different order, and/or if the components in the described system, architecture, device, or circuit are combined in different ways, and/or replaced or added by other components or their equivalents Described system, architecture, device or circuit components, you can get suitable results. Therefore, the scope of the present disclosure is not limited by the specific embodiments, but by the scope of the patent application and their equivalents, and all modifications within the scope of the patent application and their equivalents will be understood to be included in the present disclosure in.

100, 200, 300, 400, 500, 600: Acoustic wave resonator 110: substrate 115: insulating layer 120, 220, 320, 420, 520, 620: resonance part 121, 521: first electrode 123: Piezo layer 123a: Piezoelectric part 123b: curved part 125, 125', 225, 325, 425, 525: second electrode 125': preliminary second electrode 127, 227, 327, 427, 527, 627: protective layer 129, 529: third electrode 140: Sacrifice Layer 145: Etching stop 145a: etch stop layer 150: film 170: Insert layer 170a, 172: lower insertion layer 170b, 173, 270b, 370b: upper insertion layer 171: Insulation insertion layer 172a: first insertion layer 172b: second insertion layer 180: the first metal layer 190: second metal layer 1231: inclined part 1232, E: extension C: cavity H: introduction hole I-I': line L: inclined surface P: pattern R: Vertical interface S: Central part W1, W2: distance θ: tilt angle

Fig. 1 is a plan view of an acoustic wave resonator according to an example. Fig. 2 is a cross-sectional view taken along the line I-I' of Fig. 1. 3 to 6 are diagrams illustrating a method of manufacturing an acoustic wave resonator according to an example. FIG. 7 is a schematic cross-sectional view showing an acoustic wave resonator according to another example. FIG. 8 is a schematic cross-sectional view showing an acoustic wave resonator according to another example. Fig. 9 is an enlarged view of the upper insertion layer of Fig. 8. Fig. 10 is a schematic cross-sectional view showing an acoustic wave resonator according to another example. Fig. 11 is an enlarged view of the lower insertion layer of Fig. 10. FIG. 12 is a schematic cross-sectional view showing an acoustic wave resonator according to another example. FIG. 13 is a schematic cross-sectional view showing an acoustic wave resonator according to another example. Throughout the drawings and the detailed description, the same reference numerals indicate the same elements. The drawings may not be drawn to scale. For clarity, description, and convenience, the relative sizes, proportions, and depictions of elements in the drawings may be exaggerated.

100: Acoustic wave resonator

110: substrate

115: insulating layer

120: resonance part

121: first electrode

123: Piezo layer

123a: Piezoelectric part

123b: curved part

125: second electrode

127: protective layer

129: Third electrode

140: Sacrifice Layer

145: Etching stop

150: film

170: Insert layer

170a: Lower insertion layer

170b: Upper insert layer

180: the first metal layer

190: second metal layer

1231: inclined part

1232, E: extension

C: cavity

I-I': line

L: inclined surface

S: Central part

θ: tilt angle

Claims (18)

An acoustic wave resonator, the acoustic wave resonator comprising: Substrate The resonant part includes a central part in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on the substrate and an extension part provided along an outer periphery of the central part; and The first metal layer is provided outside the resonance part to be electrically connected to the first electrode, Wherein, the extension portion includes a lower insertion layer, and the lower insertion layer is disposed on the upper surface of the first electrode or the lower surface of the first electrode, Wherein, the piezoelectric layer includes a piezoelectric portion and a curved portion, the piezoelectric portion is provided in the central portion, the curved portion is provided in the extension portion and is inclined according to the shape of the lower insertion layer Extend from the piezoelectric part, and Wherein, the lower insertion layer is formed of a conductive material to extend the electrical path between the first electrode and the first metal layer. As the acoustic wave resonator described in item 1 of the scope of patent application, the acoustic wave resonator further includes: A second metal layer disposed outside the resonance part to be electrically connected to the second electrode; and The upper insertion layer is provided in the extension part and on the upper surface or the lower surface of the second electrode, and extends the electrical path between the second electrode and the second metal layer. The acoustic wave resonator according to claim 2, wherein the second electrode is spaced apart from the second metal layer, and the second electrode is electrically connected to the second metal layer through the upper insertion layer Metal layer. According to the acoustic wave resonator described in item 2 of the scope of patent application, the acoustic wave resonator further includes: The third electrode is arranged on the same plane as the first electrode and is spaced apart from the first electrode, Wherein, the second electrode is electrically connected to the third electrode through the second metal layer. The acoustic wave resonator according to claim 2, wherein the upper insertion layer is spaced apart from the boundary between the central part and the extension part, Wherein, the extension part further includes a first reflection area and a second reflection area, the first reflection area is disposed between the boundary and the upper insertion layer, and the second reflection area is disposed on the first reflection area. Outside the reflective area, and Wherein, the upper insertion layer and the second electrode are disposed in the second reflection area together. The acoustic wave resonator according to claim 1, wherein the lower insertion layer is formed of a material having an acoustic impedance lower than the acoustic impedance of the piezoelectric layer and the acoustic impedance of the first electrode. The acoustic wave resonator according to claim 1, wherein the piezoelectric layer is formed using aluminum nitride, the first electrode is formed using molybdenum, and the lower insertion layer is formed using aluminum or aluminum alloy. The acoustic wave resonator according to the first item of the scope of patent application, wherein the lower insertion layer is spaced apart from the boundary of the central part, Wherein, the extension portion further includes a first reflection area and a second reflection area, the first reflection area is disposed between the boundary and the lower insertion layer, and the second reflection area is disposed on the first reflection area. Outside the reflective area, and Wherein, the lower insertion layer and the second electrode are arranged in the second reflection area together. The acoustic wave resonator according to item 8 of the scope of patent application, wherein the acoustic impedance of the second reflection area is lower than the acoustic impedance of the first reflection area. As the acoustic wave resonator described in item 1 of the scope of patent application, the acoustic wave resonator further includes: An insulating insertion layer is provided between the lower insertion layer and the piezoelectric layer and causes the bending part to bulge. The acoustic wave resonator described in claim 1, wherein the thickness of the extension portion is greater than the thickness of the central portion. An acoustic wave resonator, the acoustic wave resonator comprising: Substrate The resonant part includes a central part in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on the substrate and an extension part provided along the outer periphery of the central part; The lower insertion layer is provided in the extension part and is provided on the upper surface of the first electrode or the lower surface of the first electrode, Wherein the lower insertion layer is spaced apart from the boundary between the central portion and the extension portion, and Wherein, the extension portion includes a first reflection area and a second reflection area, the first reflection area is disposed between the boundary and the lower insertion layer, and the lower insertion layer and the second electrode are together It is arranged in the second reflection area. The acoustic wave resonator according to claim 12, wherein the piezoelectric layer includes a piezoelectric part and an inclined part, the piezoelectric part is disposed in the central part, and the inclined part is disposed in the In the extension portion and obliquely extending from the piezoelectric portion according to the shape of the lower insertion layer, and Wherein, the first reflection area and the second reflection area are arranged in a range where the inclined portion is provided. The acoustic wave resonator according to claim 12, wherein the lower insertion layer is formed of a conductive material. The acoustic wave resonator according to claim 12, wherein the inclination angle of the inclined portion is in the range of 5° to 70°. A method of manufacturing an acoustic wave resonator, the method comprising: The resonance part is formed by the following steps: Stacking the first electrode, the piezoelectric layer and the second electrode on the substrate, and Forming a lower insertion layer including a conductive material on the upper surface of the first electrode or the lower surface of the first electrode; and After forming the resonance part, a first metal layer is formed on the lower insertion layer. The method according to claim 16, wherein the resonant part includes a central part and a side edge in which the first electrode, the piezoelectric layer, and the second electrode are sequentially stacked on the substrate. An extension portion provided on the periphery of the central portion, and Wherein, the lower insertion layer is provided in the extension part and is spaced a predetermined distance from the boundary between the central part and the extension part. The method according to item 17 of the scope of application, wherein the extension includes a first reflection area and a second reflection area, and the first reflection area is disposed between the boundary and the lower insertion layer, so The second reflection area is disposed outside the first reflection area, and the lower insertion layer and the second electrode are disposed in the second reflection area together.

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