Rf360 Singapore Pte. Ltd.

Qualcomm Incorporated

Snaptrack Incorporated

Rf360 Europe Gmbh

Matthias Knapp

Ingo Bleyl

Christian Huck

Werner Ruile

Markus Hauser

Manuel Sabbagh

Philipp Michael Jäger

Gholamreza Dadgar Javid

Guenter Scheinbacher

Benno Blaschke

Marc Konstantin Dietrich

Michael Smirnow

A surface acoustic wave device () is provided using a layered substrate system with a special material and a special cut of a piezoelectric thin film () selected for utilizing Rayleigh mode. The proper choice of the material and the cut of the piezoelectric thin film leads to a low velocity of the excited wave mode, which allows the usage of smaller devices without deteriorating other performance parameters according to specifications.

Thin-film saw device utilizing rayleigh mode

A SAW resonator with reduced spurious modes is provided. The resonator comprises a (111) silicon carrier substrate (CS), an electrode structure (ES) and a piezoelectric layer (PIL). The carrier substrate has a crystal orientation with the Euler angles (−45°±10°; −54°±10°; 60°±30°) and the piezoelectric layer comprises LiTaOand has a crystal orientation with the Euler angles (0°; 56°±8°; 0°). There may be intermediate layers (IL, IL) of SiOand amorphous or polycrystalline materials. In addition a silicon nitride layer is provided as passivation (PAL). Electrodes are made of aluminum. Thicknesses of all layers are selected in particular ranges to optimize SAW behaviour.

Thin-film LiTaOSAW resonator on silicon substrate with reduced spurious modes

An apparatus is disclosed for a surface-acoustic-wave filter with a compensation layer having multiple densities. In an example aspect, the apparatus includes at least one surface-acoustic-wave filter with a piezoelectric layer, a substrate layer, and a compensation layer positioned between the piezoelectric layer and the substrate layer. The compensation layer includes a first portion having a first density and a second portion having a second density. The second density is greater than the first density. The first portion is positioned closer to the piezoelectric layer as compared to the second portion. The second portion is positioned closer to the substrate layer as compared to the first portion.

Surface-acoustic-wave (SAW) filter with a compensation layer having multiple densities

In at least one embodiment, the SAW device comprises a carrier substrate (), a piezoelectric thin-film () on the carrier substrate, an interdigital electrode structure () on the piezoelectric thin-film and a layer stack () of waveguide layers. The layer stack is arranged between the carrier substrate and the piezoelectric thin-film. The layer stack comprises a first waveguide layer () and second waveguide layer (), wherein a sound velocity in the first waveguide layer is at least 1.5 times as great as in the second waveguide layer. The device may comprise a temperature compensating layer () and a trap rich layer () between the layer stack and the carrier substrate.

Thin-film saw device with multilayer waveguide

A thin film SAW device comprises a carrier substrate (CA), a TCF compensating layer (CL), a piezoelectric layer (PL), and an IDT electrode (EL) on top of the piezoelectric layer. A functional layer (FL) is arranged between piezoelectric layer and TCF compensating layer to further reduce the TCF. The material properties of the functional layer match those of the piezoelectric layer in view of acoustic velocity, density and stiffness such that they do not deviate from each other by more than 10% without having piezoelectric effect. The functional layer my be of the same crystalline constitution as the useful piezoelectric layer but without piezoelectric properties.

Thin film saw device

For a multilayer SAW device arranged on a carrier substrate it is proposed to use a specific material for the carrier substrate. If a silicon material having a selected range of Euler angles is used as a material for the carrier substrat improved suppression of disturbing signals is achieved.

Saw device with suppressed spurious mode signals

A TF-SAW resonator with improved quality factor is provided. The resonator has its piezoelectric material in the form of a thin film and an electrode structure arranged on the piezoelectric layer. Pitch (P) and metallization ratio (n) are chosen to maximize the quality factor (Q).

TF-SAW resonator with improved quality factor, RF filter and method of manufacturing a TF-SAW resonator

A SAW device having a stacked design of functional layers is proposed that is build up on a carrier substrate (SUB) that is chosen to provide a high acoustic velocity. The stack further comprises a thin TCF compensation layer (TCL), a thin film piezoelectric layer (PEL) and a set of interdigital electrodes (IDE) on top of the piezoelectric layer. Energy of the desired mode mainly in the high acoustic velocity material. Despite the high possible operating frequencies the SAW device can reliably be manufactured with present lithographic techniques.

Saw device with composite substrate for ultra high frequencies

For a component operating with acoustic waves, it is proposed to provide a compensation layer on the component for compensating for a negative temperature coefficient of the frequency, which includes a material based on a chemical compound made up of at least two elements, which has a negative thermal expansion coefficient.

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Munich, Germany

Matthias Knapp