Rf Micro Devices, Inc.

Qorvo Us, Inc.

Sergei Zhgoon

Kushal Bhattacharjee

An apparatus includes a substrate, a thin film piezoelectric layer, a transducer, and a low resistivity layer. The thin film piezoelectric layer is over the substrate, the transducer includes a number of electrodes in contact with the thin film piezoelectric layer and configured to transduce an acoustic wave in the thin film piezoelectric layer. The low resistivity layer is between at least a portion of the substrate and the thin film piezoelectric layer. By providing the low resistivity layer between at least a portion of the substrate and the thin film piezoelectric layer, a spurious response of the apparatus may be significantly reduced, thereby improving the performance thereof.

Solidly mounted layer thin film device with grounding layer

A MEMS vibrating device includes a substrate, at least one anchor on a surface of the substrate, and a vibrating body suspended over the substrate by the at least one anchor. The vibrating body includes a first piezoelectric thin-film layer, a second piezoelectric thin-film layer over the first piezoelectric thin-film layer, and an inter-digital transducer embedded between the first piezoelectric thin-film layer and the second piezoelectric thin-film layer. Embedding the inter-digital transducer between the first piezoelectric thin-film layer and the second piezoelectric thin-film layer may result in enhanced vibrational characteristics of the MEMS vibrating device, thereby increasing the performance thereof.

Enhanced MEMS vibrating device

A micro-electrical-mechanical system (MEMS) vibrating structure includes a carrier substrate, a first anchor, a second anchor, a single crystal piezoelectric body, and a conducting layer. The first anchor and the second anchor are provided on the surface of the carrier substrate. The single-crystal piezoelectric body is suspended between the first anchor and the second anchor, and includes a uniform crystalline orientation defined by a set of Euler angles. The single-crystal piezoelectric body includes a first surface parallel to and facing the surface of the carrier substrate on which the first anchor and the second anchor are formed and a second surface opposite the first surface. The conducting layer is inter-digitally dispersed, and is formed on the second surface of the single-crystal piezoelectric body. The first surface of the single-crystal piezoelectric body is left exposed.

MEMS vibrating structure using an orientation dependent single-crystal piezoelectric thin film layer

A micro-electrical-mechanical system (MEMS) vibrating structure includes a carrier substrate, a first anchor, a second anchor, a single crystal piezoelectric body, a first conducting layer, and a second conducting layer. The first anchor and the second anchor are provided on the surface of the carrier substrate. The single-crystal piezoelectric body is suspended between the first anchor and the second anchor, and includes a uniform crystalline orientation defined by a set of Euler angles. The single-crystal piezoelectric body includes a first surface parallel to and facing the surface of the carrier substrate on which the first anchor and the second anchor are formed and a second surface opposite the first surface. The first conducting layer is inter-digitally dispersed on the second surface of the single-crystal piezoelectric body. The second conducting layer is inter-digitally dispersed on the first surface of the single-crystal piezoelectric body.

A method of manufacturing composite structures, or composite substrates, for a Surface Acoustic Wave (SAW) device are provided. In one embodiment of the present disclosure, a piezoelectric substrate is provided. A supporting substrate is formed over a first surface of the piezoelectric substrate. The first surface of the piezoelectric substrate may be unpolished. A second surface of the piezoelectric substrate is then processed to a desired thickness and polished. SAW device components such as, for example, interdigitated transducers (IDTs) and reflectors are then formed on the polished surface of the piezoelectric substrate. The supporting substrate may be formed using any desired type of deposition or growth process.

Method of manufacturing SAW device substrates

The present invention provides a composite structure having a supporting substrate between a piezoelectric substrate and a compensation layer. The materials used to form the piezoelectric substrate and the compensation layer in isolation, have higher thermal coefficients of expansion (TCE) relative to the TCE of the materials forming the supporting substrate. Once the composite structure is created, the piezoelectric substrate and compensation layer tend to expand and contract in a similar manner as temperature changes. The expansion and contraction forces applied to the supporting substrate by the piezoelectric substrate due to temperature changes are substantially countered by similar opposing forces applied by the compensation layer, resulting in the opposing forces substantially counteracting one another. Due to the counteraction, the composite structure resists bending or warping, reducing expansion and contraction and increasing stress of the piezoelectric substrate, and thus reducing the effective TCE and TCF of the piezoelectric substrate.

Growing community of inventors

Moscow, Russia

Sergei Zhgoon