Abstract: A bulk acoustic wave device and a capacitor in a bulk acoustic wave device are disclosed. The bulk acoustic wave device can include a resonator, an interconnect structure, and a capacitor. The resonator includes a first electrode, a second electrode, a piezoelectric layer between the first and second electrodes, and a passivation layer over the second electrode such that the second electrode is positioned between the piezoelectric layer and the passivation layer. The interconnect structure includes a conductive layer. The capacitor includes the passivation layer positioned between the conductive layer and the first or second electrode in a first direction. The capacitor, the resonator, and the interconnect structure are positioned in a second direction different from the first direction.

Abstract: Disclosed herein are embodiments of a method of manufacturing film bulk acoustic wave resonators. The method comprises forming a sacrificial layer over a surface of a substrate to form a plurality of film bulk acoustic wave resonators on the surface of the substrate, forming a piezoelectric film on the surface of the substrate to cover the sacrificial layer, and removing the sacrificial layer to form an air gap between the surface of the substrate and the piezoelectric film that has covered the sacrificial layer, the air gap corresponding to each of the plurality of film bulk acoustic wave resonators. The step of forming the piezoelectric film includes controlling a concentration distribution of an additive added to the piezoelectric film across the surface of the substrate to suppress a variation of the acoustic velocity of the piezoelectric film depending on a position on the main surface of the substrate.

Abstract: An infrared ray detecting element includes: a substrate having a cavity; an infrared ray detecting portion including, sequentially stacked, a lower electrode layer, a detection layer, and an upper electrode layer; first and second support portions which support the infrared ray detecting portion above the cavity; and first and second external lead portions for leading electrical signals outputted from the infrared ray detecting portion, to the outside. The first support portion includes, sequentially stacked, a first upper wiring pattern, a first insulating layer, and a first lower wiring pattern. The upper electrode layer is connected to the first external lead portion via the first upper wiring pattern. The second support portion includes, sequentially stacked, a second upper wiring pattern, a second insulating layer, and a second lower wiring pattern. The lower electrode layer is connected to the second external lead portion via the second lower wiring pattern.

Abstract: An infrared ray detecting element includes: a substrate having a cavity; an infrared ray detecting portion including, sequentially stacked, a lower electrode layer, a detection layer, and an upper electrode layer; first and second support portions which support the infrared ray detecting portion above the cavity; and first and second external lead portions for leading electrical signals outputted from the infrared ray detecting portion, to the outside. The first support portion includes, sequentially stacked, a first upper wiring pattern, a first insulating layer, and a first lower wiring pattern. The upper electrode layer is connected to the first external lead portion via the first upper wiring pattern. The second support portion includes, sequentially stacked, a second upper wiring pattern, a second insulating layer, and a second lower wiring pattern. The lower electrode layer is connected to the second external lead portion via the second lower wiring pattern.

Abstract: An electrode foil includes a substrate and a coarse film layer having a void therein and formed on the substrate. The coarse film layer includes at least a first coarse film layer formed on the substrate. The first coarse film layer is composed of arrayed first columnar bodies. Each of the first columnar bodies is composed of metallic microparticles stacked on a surface of the substrate and extending in a curve from the surface of the substrate.

Abstract: An electrode foil including a substrate made of metal material, a first layer made of metal oxide and formed on the substrate, a second layer made of TiNxOy (x>y>0) and formed on the first layer, and a third layer made of TiNxOy (0<x<y) and formed on the second layer.

Abstract: A capacitor comprising a capacitor element including a substrate having first and second faces, a porous first rough surface layer formed on the first face and having pores, a first inner conductive polymer layer formed in the pores, a first outer conductive polymer layer formed on the inner conductive polymer layer, a porous second rough surface layer formed on the second face and having pores, a second inner conductive polymer layer formed in the pores, a second outer conductive polymer layer formed on the second inner conductive polymer layer, and a dielectric layer formed on surfaces of the first and the second rough surface layer. A surface area of the second rough surface layer is smaller than that of the first rough surface layer. The second outer conductive polymer layer is thicker than the first outer conductive polymer layer. This structure enables to eliminate warpage of a capacitor element.

Abstract: A capacitor comprising a capacitor element including a substrate having first and second faces, a porous first rough surface layer formed on the first face and having pores, a first inner conductive polymer layer formed in the pores, a first outer conductive polymer layer formed on the inner conductive polymer layer, a porous second rough surface layer formed on the second face and having pores, a second inner conductive polymer layer formed in the pores, a second outer conductive polymer layer formed on the second inner conductive polymer layer, and a dielectric layer formed on surfaces of the first and the second rough surface layer. A surface area of the second rough surface layer is smaller than that of the first rough surface layer. The second outer conductive polymer layer is thicker than the first outer conductive polymer layer. This structure enables to eliminate warpage of a capacitor element.

Abstract: An acoustic wave device includes an interdigital transducer (IDT) electrode and a separate electrode facing the IDT electrode. The IDT electrode includes first and second comb-shaped electrode facing each other. The first comb-shaped electrode includes a first bus bar, first interdigitated electrode fingers, and first dummy electrode fingers. The second comb-shaped electrode includes a second bus bar second interdigitated electrode fingers interdigitated with the first interdigitated electrode fingers, second dummy electrode fingers facing the first interdigitated electrode fingers, weighted parts, and a non-weighted part. The weighted parts have electrodes at spaces between the second interdigitated electrode fingers and the second dummy electrode fingers. In the non-weighted part, there is no electrode at a space out of the spaces which is closest to the separate electrode in the non-interdigitated region.

Abstract: An electrode foil including a substrate made of metal material, a first layer made of metal oxide and formed on the substrate, a second layer made of TiNxOy (x>y>0) and formed on the first layer, and a third layer made of TiNxOy (0<x<y) and formed on the second layer.

Abstract: An acoustic wave element includes a piezoelectric body, first and second interdigital transducer (IDT) electrodes provided on an upper surface of the piezoelectric body, and a first dielectric layer provided on the upper surface of the piezoelectric body to cover the first and second IDT electrodes. The first dielectric layer has a first part directly above the first IDT electrode and a second part directly above the second IDT electrode. The height of an upper surface of the second part of the first dielectric layer is larger than the height of an upper surface of the first part of the first dielectric layer. This acoustic wave element has a preferable temperature characteristic and electromechanical coupling factor.

Abstract: An electrode foil includes a substrate and a coarse film layer having a void therein and formed on the substrate. The coarse film layer includes at least a first coarse film layer formed on the substrate. The first coarse film layer is composed of arrayed first columnar bodies. Each of the first columnar bodies is composed of metallic microparticles stacked on a surface of the substrate and extending in a curve from the surface of the substrate.

Abstract: An electrode foil includes a substrate made of metal and a rough layer disposed on a surface of the substrate and including plural fine metallic particles. The rough layer includes a lower layer, an intermediate layer which is disposed on the lower layer and is more distanced from the substrate than the lower layer is, and an upper layer which is disposed on the intermediate layer and is more distanced from the substrate than the intermediate layer is. The mode of diameters of fine particles in the intermediate layer is greater than the mode of diameters of the fine particles in the upper and lower layers. This electrode foil provides a capacitor having a small leakage current.

Abstract: An acoustic wave element includes a piezoelectric body, first and second interdigital transducer (IDT) electrodes provided on an upper surface of the piezoelectric body, and a first dielectric layer provided on the upper surface of the piezoelectric body to cover the first and second IDT electrodes. The first dielectric layer has a first part directly above the first IDT electrode and a second part directly above the second IDT electrode. The height of an upper surface of the second part of the first dielectric layer is larger than the height of an upper surface of the first part of the first dielectric layer.

Abstract: An electrode foil includes a substrate made of metal and a rough layer disposed on a surface of the substrate and including plural fine metallic particles. The rough layer includes a lower layer, an intermediate layer which is disposed on the lower layer and is more distanced from the substrate than the lower layer is, and an upper layer which is disposed on the intermediate layer and is more distanced from the substrate than the intermediate layer is. The mode of diameters of fine particles in the intermediate layer is greater than the mode of diameters of the fine particles in the upper and lower layers. This electrode foil provides a capacitor having a small leakage current.

Abstract: An acoustic boundary wave device includes a piezoelectric body, an IDT layer formed on the piezoelectric body, a pad electrode layer formed on the piezoelectric body and connected to the IDT layer, a first dielectric layer formed on the piezoelectric body and covering at least a part of the IDT electrode layer, and a second dielectric layer formed on the piezoelectric body, covering the first dielectric layer, and having an opening through which at least a part of a top face of the pad electrode layer is exposed. The metal forming lateral faces of the pad electrode layer diffuses more readily into the first dielectric layer than into the second dielectric layer. The second dielectric layer covers the lateral faces of the pad electrode layer and prevents the first dielectric layer from touching the lateral faces of the pad electrode layer.

Abstract: An acoustic wave device includes an interdigital transducer (IDT) electrode and a separate electrode facing the IDT electrode. The IDT electrode includes first and second comb-shaped electrode facing each other. The first comb-shaped electrode includes a first bus bar, first interdigitated electrode fingers, and first dummy electrode fingers. The second comb-shaped electrode includes a second bus bar second interdigitated electrode fingers interdigitated with the first interdigitated electrode fingers, second dummy electrode fingers facing the first interdigitated electrode fingers, weighted parts, and a non-weighted part. The weighted parts have electrodes at spaces between the second interdigitated electrode fingers and the second dummy electrode fingers. In the non-weighted part, there is no electrode at a space out of the spaces which is closest to the separate electrode in the non-interdigitated region.

Abstract: An elastic wave element includes a piezoelectric substrate, an interdigital electrode provided on the piezoelectric substrate, a silicon oxide film covering the interdigital electrode, and a silicon nitride oxide film provided on the silicon oxide film. A film thickness H of the silicon oxide film and a wave length ? of an elastic wave propagating through the piezoelectric substrate satisfies a relation of H/??0.15. The elastic wave element reduces fluctuation of propagation characteristics of elastic waves, and has high reliability.

Abstract: An acoustic boundary wave device includes a piezoelectric body, an IDT layer formed on the piezoelectric body, a pad electrode layer formed on the piezoelectric body and connected to the IDT layer, a first dielectric layer formed on the piezoelectric body and covering at least a part of the IDT electrode layer, and a second dielectric layer formed on the piezoelectric body, covering the first dielectric layer, and having an opening through which at least a part of a top face of the pad electrode layer is exposed. The metal forming lateral faces of the pad electrode layer diffuses more readily into the first dielectric layer than into the second dielectric layer. The second dielectric layer covers the lateral faces of the pad electrode layer and prevents the first dielectric layer from touching the lateral faces of the pad electrode layer.

Abstract: An elastic wave element includes a piezoelectric substrate, an interdigital electrode provided on the piezoelectric substrate, a silicon oxide film covering the interdigital electrode, and a silicon nitride oxide film provided on the silicon oxide film. A film thickness H of the silicon oxide film and a wave length ? of an elastic wave propagating through the piezoelectric substrate satisfies a relation of H/??0.15. The elastic wave element reduces fluctuation of propagation characteristics of elastic waves, and has high reliability.