A BAW device comprises a first BAW resonator (1) and a second BAW resonator (2). The first BAW resonator and the second BAW resonator each comprise a first electrode (11, 21), a second electrode (12, 22) and a piezoelectric layer (13, 23) being arranged in each case between the first electrode and the second electrode of the associated BAW resonator. The first electrodes, the second electrodes and the piezoelectric layers of both BAW resonators are designed essentially identically. A first conductor track (24) extends from the first electrode of the second BAW resonator to a third electric element (3) of the BAW device and electrically connects said first electrode with said third electric element. A first dummy conductor track (14) extends from the first electrode of the first BAW resonator, is electrically connected to said first electrode and, apart from said first electrode, is not electrically connected to any further electric element. The first dummy conductor track is designed such that it influences the acoustic and capacitive properties of the first BAW resonator essentially in the same way as the first conductor track influences the acoustic and capacitive properties of the second BAW resonator.

A method for manufacturing a resonator that effectively addresses variations in resistivity for each wafer. The method for manufacturing a resonator includes forming a Si oxide film on a surface of a degenerated Si wafer, where the Si oxide film has a thickness set that is based on the doping amount of impurity in the degenerated Si wafer.

A thin-film bulk acoustic resonator, a semiconductor apparatus including the acoustic resonator and its manufacturing methods are presented. The thin-film bulk acoustic resonator includes a lower dielectric layer, a first cavity inside the lower dielectric layer, an upper dielectric layer, a second cavity inside the upper dielectric layer, and a piezoelectric film that is located between the first and the second cavities and continuously separates these two cavities. The plan views of the first and the second cavities have an overlapped region, which is a polygon that does not have any parallel sides. The piezoelectric film in this inventive concept is a continuous film without any through-hole in it, therefore it can offer improved acoustic resonance performance.

A thin-film bulk acoustic resonator, a semiconductor apparatus including the acoustic resonator and its manufacturing method are presented. The thin-film bulk acoustic resonator includes a lower dielectric layer, a first cavity inside the lower dielectric layer, an upper dielectric layer, a second cavity inside the upper dielectric layer, and a piezoelectric film that is located between the first and second cavities and continuously separates these two cavities. The plan views of the first and the second cavities have an overlapped region, which is a polygon that does not have any parallel sides. The piezoelectric film of this inventive concept is a continuous film without any through-hole in it, therefore it can offer improved acoustic resonance performance.

A resonator may include a first dielectric member, a second dielectric member, and a composite member. The first dielectric member may have a first cavity. The composite member may include a piezoelectric layer and may overlap at least one of the first dielectric member and the second dielectric member. At least one of the second dielectric member and the composite member may have a second cavity. The piezoelectric layer may be positioned between the first cavity and the second cavity. A projection of the first cavity in a direction perpendicular to a flat side of the first dielectric member and a projection of the second cavity in the direction may intersect each other to form a polygon. No two edges of the polygon may be parallel to each other.

A Bulk Acoustic Wave (BAW) resonator with an electrically isolated Border (BO) ring is provided. One BAW resonator includes a bottom electrode and a piezoelectric layer over the bottom electrode and having a top surface with a first portion and second portion about the first portion. The BAW resonator also includes a top electrode over the first portion of the piezoelectric layer and a BO ring including a non-conductive portion that is over the second portion of the piezoelectric layer and adjacent to the piezoelectric layer. The BAW resonator may be a Solidly Mounted BAW (SMR-BAW) resonator or a Film BAW Resonator (FBAR). A radio frequency filter including a ladder configuration with the above BAW resonator as a series BAW resonator and methods for fabricating the above BAW resonator are also provided.

A wafer-level package for micro-acoustic devices and a method of manufacture is provided. The package comprises a base wafer with electric device structures. A frame structure is sitting on top of the base wafer enclosing particular device areas for the micro-acoustic devices. A cap wafer provided with a thin polymer coating is bonded to the frame structure to form a closed cavity over each device area and to enclose within the cavity the device structures arranged on the respective device area.

Acoustic resonator devices, filters, and methods are disclosed. An acoustic resonator includes a substrate and a lithium niobate (LN) plate having front and back surfaces and a thickness ts. The back surface faces the substrate. A portion of the LN plate forms a diaphragm spanning a cavity in the substrate. An interdigital transducer (IDT) is on the front surface of the LN plate with interleaved fingers of the IDT on the diaphragm. The LN plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a shear primary acoustic wave in the diaphragm. Euler angles of the LN plate are [0°, β, 0°], where 0≤β≤60°. A thickness of the interleaved fingers of the IDT is greater than or equal to 0.8 ts and less than or equal to 2.0 ts.

A filter with bulk acoustic wave devices is disclosed. The filter includes a first bulk acoustic wave resonator and a second bulk acoustic wave resonator. The first bulk acoustic wave resonator includes a first raised frame structure. The first raised frame structure is a multi-layer raised frame structure. The second bulk acoustic wave resonator includes a second raised frame structure. The first raised frame structure has at least one more raised frame layer than the second raised frame structure.

Devices and methods related to film bulk acoustic resonators. In some embodiments, a film bulk acoustic resonator can be manufactured by a method that includes forming a first electrode having a first lateral shape and providing a piezoelectric layer on the first electrode. The method can further include forming a second electrode having a second lateral shape on the piezoelectric layer such that the piezoelectric layer is between the first and second electrodes. The forming of the first electrode and the forming of the second electrode can include selecting and arranging the first and second lateral shapes to provide a resonator shape defined by an outline of an overlap of the first and second electrodes, such that the resonator shape includes N curved sections joined by N vertices of an N-sided polygon, and such that the resonator shape has no axis of symmetry.