Abstract: A bulk-acoustic wave (BAW) resonator includes a central portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on a substrate, and an extension portion extending externally from the central portion, and an insertion layer and a loss prevention film are disposed in the extension portion between the substrate and the second electrode. The loss prevention film is formed to have a thickness of 50 ? to 500 ?. The insertion layer is stacked on the loss prevention film, and has a side surface opposing the central portion, the side surface is formed as a first inclined surface having a first inclination angle. The loss prevention film has a side surface opposing the central portion, the side surface is formed as a second inclined surface having a second inclination angle. The second inclination angle is formed to be greater than the first inclination angle.

Abstract: Disclosed is a bulk acoustic wave resonator (BAWR). The BAWR includes a bulk acoustic wave resonance unit with a first electrode, a second electrode, and a piezoelectric layer. The piezoelectric layer is disposed between the first electrode and the second electrode. An air edge is formed at a distance from a center of the bulk acoustic wave resonance unit.

Abstract: A bulk-acoustic wave resonator includes a resonator including a central portion in which a first electrode, a piezoelectric layer, and a second electrode are sequentially stacked on a substrate, and an extension portion disposed along a periphery of the central portion; and an insertion layer disposed between the piezoelectric layer and the substrate in the extension portion to raise the piezoelectric layer. The insertion layer includes a first insertion layer having a first inclined surface formed along a side surface facing the central portion and a second inclined surface disposed between the first insertion layer and the piezoelectric layer and having a second inclined surface spaced apart from the first inclined surface with respect to a surface direction of the first electrode. The first insertion layer is thinner than the second insertion layer.

Abstract: A bulk-acoustic wave resonator includes a substrate; a lower electrode, disposed on the substrate, comprising a first inclined surface and a second inclined surface; and an insertion layer disposed on an edge of the lower electrode. The first inclined surface extends from an inclined surface of the insertion layer in a region disposed inside the insertion layer. The second inclined surface extends from the first inclined surface in a region inside a region of the first inclined surface.

Abstract: A bulk acoustic wave resonator includes a substrate; a central portion including a first portion of a first electrode, a first portion of a piezoelectric layer, and a first portion of a second electrode laminated in order on the substrate; and a reflective region disposed laterally of the central portion and including a second portion of the first electrode, an insertion layer, a second portion of the piezoelectric layer, and a second portion of the second electrode. A side surface of the insertion layer adjacent to the central portion has an inclined surface, the first portion of the second electrode and the second portion of the second electrode are coplanar, and an end of the second electrode overlaps the inclined surface of the insertion layer in the reflective region.

Abstract: A bulk acoustic resonator includes a substrate, a frequency control layer changing a resonant frequency or antiresonant frequency of the bulk acoustic resonator according to a thickness of the frequency control layer, a piezoelectric layer disposed between the frequency control layer and the substrate, a first electrode disposed between the piezoelectric layer and the substrate, a second electrode disposed between the piezoelectric layer and the frequency control layer, a metal layer connected to the first electrode or the second electrode, and a protective layer disposed between the second electrode and the frequency control layer, wherein the frequency control layer covers a larger area than that of the protective layer.

Abstract: A bulk acoustic wave resonator is provided. The bulk acoustic wave resonator includes a board; a resonant portion including a first electrode, a piezoelectric layer, and a second electrode, and disposed on the board, and a temperature compensation layer disposed on the resonant portion, wherein the temperature compensation layer includes a temperature compensation portion formed of a dielectric and a loss compensation portion formed of a material different from a material of the temperature compensation portion, and wherein each of the temperature compensation portion and the loss compensation portion includes a plurality of linear patterns, and the linear patterns of the temperature compensation portion and the linear patterns of the loss compensation portion are alternately disposed.

Abstract: An acoustic wave resonator includes a resonating part disposed on and spaced apart from a substrate by a cavity, the resonating part including a membrane layer, a first electrode, a piezoelectric layer, and a second electrode that are sequentially stacked. 0 ???Mg?170 ? may be satisfied, ?Mg being a difference between a maximum thickness and a minimum thickness of the membrane layer disposed in the cavity.

Abstract: An acoustic resonator includes: a resonating unit including a resonating unit including a piezoelectric layer and first and second electrodes disposed on a lower side and an upper side of the piezoelectric layer, respectively; a substrate disposed on a lower side of the resonating unit; a support unit providing a cavity between the substrate and the resonating unit; and an intermediate metal layer separated from the second electrode and disposed in the resonating unit such that at least a portion thereof is surrounded by the piezoelectric layer and the second electrode.

Abstract: An acoustic resonator includes: a resonating unit including a piezoelectric layer, a first electrode disposed on a lower side of the piezoelectric layer, and a second electrode disposed on an upper side of the piezoelectric layer; a substrate disposed below the resonating unit; a support unit forming a cavity between the substrate and the resonating unit; and a pillar extending through the cavity and connecting the resonating unit to the substrate. The resonating unit further includes a first insertion layer disposed above the pillar.

Abstract: An acoustic resonator includes a substrate, an insulation layer disposed on the substrate, a resonating portion disposed on the insulation layer and having a first electrode, a piezoelectric layer, and a second electrode, stacked thereon, a cavity disposed between the insulation layer and the resonating portion, a protruded portion having a plurality of protrusions disposed on a lower surface of the cavity, and a hydrophobic layer disposed on an upper surface of the cavity and a surface of the protruded portion.

Abstract: A bulk acoustic wave resonator includes: a substrate; a membrane layer forming a cavity together with the substrate; a lower electrode disposed on the membrane layer; a piezoelectric layer disposed on a flat surface of the lower electrode; and an upper electrode covering a portion of the piezoelectric layer and exposing a side of the piezoelectric layer to air, wherein the piezoelectric layer includes a step portion extended from the side of the piezoelectric layer and disposed on the flat surface of the lower electrode.

Abstract: A bulk acoustic resonator includes: a substrate; a first electrode disposed on the substrate; a piezoelectric layer disposed to cover at least a portion of the first electrode; a second electrode disposed to cover at least a portion of the piezoelectric layer; and an insertion layer disposed below a partial region of the piezoelectric layer. A thickness of the first electrode in an active region in which the first electrode, the piezoelectric layer, and the second electrode overlap one another is less than a thickness of a region outside the active region. An angle of inclination of an internal side surface of the insertion layer is different from an angle of inclination of an external side surface of the insertion layer.

Abstract: A bulk-acoustic resonator includes: a substrate; a first electrode disposed on the substrate; a piezoelectric layer at least partially covering the first electrode, and including a flat portion disposed in a central region, and an extension portion disposed outside the flat portion and having at least one step portion; an insertion layer disposed on the extension portion; and a second electrode disposed on upper portions of the insertion layer and the piezoelectric layer. The extension portion includes at least one first surface and at least one second surface disposed below an upper surface of the flat portion, and a connection surface connecting an upper surface of the flat portion to the at least one first surface or the at least one second surface, or connecting first surfaces among the at least one first surface to each other or second surfaces among the at least one second surface to each other.

Abstract: A bulk-acoustic wave resonator includes a substrate, a first layer, a second layer, a membrane layer, and a resonance portion. The substrate includes a substrate protection layer. The first layer is disposed on the substrate protection layer. The second layer is disposed outside of the first layer. The membrane layer forms a cavity with the substrate protection layer and the first layer. The resonance portion is disposed on the membrane layer. Either one or both of the substrate protection layer and the membrane layer includes a protrusion disposed in the cavity.

Abstract: A bulk-acoustic wave resonator package includes a package substrate; a cover bonded to the package substrate; an acoustic wave resonator accommodated in an accommodation space defined by the package substrate and the cover; a conductive wire disposed in the accommodation space to electrically connect the acoustic wave resonator to the package substrate; and a bonding portion to fixedly couple the acoustic wave resonator to the package substrate. The bonding portion includes an adhesive member including silicon.

Abstract: An acoustic wave resonator includes a resonating part disposed on and spaced apart from a substrate by a cavity, the resonating part including a membrane layer, a first electrode, a piezoelectric layer, and a second electrode that are sequentially stacked. 0 ???Mg?170 ? may be satisfied, ?Mg being a difference between a maximum thickness and a minimum thickness of the membrane layer disposed in the cavity.

Abstract: A bulk-acoustic wave resonator is provided. The bulk-acoustic wave resonator comprises a substrate comprising an external connection electrode; a connection layer connected to the external connection electrode and disposed on the substrate; a first electrode disposed to cover at least a portion of the connection layer; a piezoelectric layer disposed to cover at least a portion of the first electrode; and a second electrode disposed to cover at least a portion of the piezoelectric layer. The connection layer may be disposed to surround a cavity and may be connected to the first electrode and the second electrode.

Abstract: A bulk-acoustic wave resonator includes: a substrate; a first electrode disposed on the substrate; a cavity disposed between the substrate and the first electrode; a piezoelectric layer covering at least a portion of the first electrode; a second electrode covering at least a portion of the piezoelectric layer; an insertion layer disposed between the first electrode and the piezoelectric layer; and a lower frame disposed in the cavity. At least a portion of the lower frame overlaps the insertion layer.

Abstract: A bulk acoustic resonator includes: a substrate including an upper surface on which a substrate protection layer is disposed; and a membrane layer forming a cavity together with the substrate, wherein a thickness deviation of either one or both of the substrate protection layer and the membrane layer is 170 ? or less.