Global Communication Semiconductors, LLC

Qorvo Us, Inc.

Liping Daniel Hou

Shing-Kuo Wang

Yuefei Yang

Robert Bruce Stokes

Kun-Mao Pan

Alvin M Kong

Dae-Jin Hyun

Dheeraj Mohata

Alexander M Vigo

Andy Chien-Hsiang Chen

Chuanxin Lian

A bulk acoustic wave resonator includes a substrate, and a stack that is supported by the substrate. The stack includes a first electrode, a multilayer buffer, a piezoelectric layer, and a second electrode. The multilayer buffer is disposed between the first electrode and the piezoelectric layer, and the piezoelectric layer is disposed between the multilayer buffer and the second electrode. The multilayer buffer includes two or more pairs of alternating layers. A first pair of the two or more pairs include a first layer of crystalline material having a first lattice constant, and a second layer of crystalline material having a lattice constant that is distinct from the first lattice constant.

Bulk acoustic wave resonator with improved structures

Devices and processes for preparing devices are described for a bulk acoustic wave resonator. A stack formed over a substrate includes a piezoelectric film element, a first (e.g., bottom) electrode coupled to a first side of the piezoelectric film element, and a second (e.g., top) electrode that is coupled to a second side of the piezoelectric film element. A cavity is positioned between the stack and the substrate. The resonator includes one or more planarizing layers, including a first planarizing layer around the cavity, wherein a first portion of the first electrode is adjacent the cavity and a second portion of the first electrode is adjacent the first planarizing layer. The resonator optionally includes an air reflector around the perimeter of the piezoelectric film element. The stack is configured to resonate in response to an electrical signal applied between the first electrode and the second electrode.

Support structure for bulk acoustic wave resonator

A device includes a semiconductor die, a source contact, a drain contact, a first passivation layer, a T-shaped gate contact, a field plate, and a second passivation layer. The semiconductor die generally includes a plurality of semiconductor layers disposed on an insulating substrate. The source contact and the drain contact are electrically coupled to a channel formed in the semiconductor layers and defining an active area of the device. The first passivation layer generally covers the active area of the device, the source contact, and the drain contact. The T-shaped gate contact may be disposed within the active area of the device. The T-shaped gate contact is generally electrically separated from the channel and comprises a column portion and a cap portion. The field plate may be disposed above the active area of the device. The field plate is generally adjacent to and laterally separated from the cap portion of the T-shaped gate contact. The second passivation layer generally covers the first passivation layer, the cap portion of the T-shaped gate contact, and the field plate.

Embedded non-overlapping source field design for improved GaN HEMT microwave performance

A bulk acoustic (BAW) resonator having a multilayer base and method of fabricating the bulk acoustic resonator is disclosed. A BAW resonator comprises a substrate having a cavity and including a frame around the cavity, a multilayer base adjacent the cavity and supported by the frame. The multilayer base includes a first layer of crystalline material having a first lattice constant and a second layer of crystalline material having a second lattice constant that is distinct from the first lattice constant. The BAW resonator further includes a stack over the multilayer base. The stack includes a first electrode formed on the multilayer base, a piezoelectric layer having a first side coupled to the first electrode and a second side opposite to the first side of the piezoelectric layer, and a second electrode coupled to the second side of the piezoelectric layer.

Bulk acoustic wave resonator with multilayer base

A bulk acoustic wave resonator with better performance and better manufacturability is described. The bulk acoustic wave resonator includes a composite piezoelectric film. The composite piezoelectric film includes a first sublayer of a first piezoelectric material, a second sublayer of a second piezoelectric material, and a third sublayer of a third piezoelectric material that is disposed between the first sublayer and the second sublayer. The first piezoelectric material has a first lattice constant, the second piezoelectric material has a second lattice constant, and the third piezoelectric material has a third lattice constant that is distinct from the first lattice constant and from the second lattice constant. The composite piezoelectric film may include a sequence of alternating sublayers of two or more distinct piezoelectric materials, or a sequence of composition graded layers having gradually changing composition.

Composite piezoelectric film and bulk acoustic resonator incorporating same

A bulk acoustic wave (BAW) resonator includes a substrate, a stack over the substrate and including a piezoelectric layer disposed between two electrode layers, and one or more edge frames. The one or more edge frames can be a raised metal frame extending parallel to a periphery of an active region of the stack and has one or more slanted cuts such that the edge frame does not form a closed loop and loss of acoustic energy in the active region through the one or more cuts is reduced, minimized or prevented. Alternatively or additionally, the one or more edge frames include a recessed edge frame in the form of a trench in the piezoelectric layer extending parallel to a boundary of the active region, and may further include a second edge frame formed on the first electrode and embedded in the piezoelectric layer.

Bulk acoustic resonator structures with improved edge frames

A single-crystal bulk acoustic wave resonators with better performance and better manufacturability and a process for fabricating the same are described. A low-acoustic-loss layer of one or more single-crystal and/or poly-crystal piezoelectric materials is epitaxially grown and/or physically deposited on a surrogate substrate, followed with the formation of a bottom electrode and then a support structure on a first side of the piezoelectric layer. The surrogate substrate is subsequently removed to expose a second side of the piezoelectric layer that is opposite to the first side. A top electrode is then formed on the second side of the piezoelectric layer, followed by further processes to complete the BAW resonator and filter fabrication using standard wafer processing steps. In some embodiments, the support structure has a cavity or an acoustic mirror adjacent the first electrode layer to minimize leakage of acoustic wave energy.

Single-crystal bulk acoustic wave resonator and method of making thereof

Devices and processes for preparing devices are described for a bulk acoustic wave resonator. A stack includes a first electrode that is coupled to a first side of a piezoelectric layer and a second electrode that is coupled to a second side of the piezoelectric layer. The stack is configured to resonate in response to an electrical signal applied between the first electrode and the second electrode. A cavity frame is coupled to the first electrode and to the substrate. The cavity frame forms a perimeter around a cavity. Optionally, a heat dissipating frame is formed and coupled to the second electrode. The cavity frame and/or the heat dissipating frame improve the thermal stability of the bulk acoustic resonator.

Devices and processes for preparing devices are described for reducing resonance of spurious waves in a bulk acoustic resonator and/or for obstructing propagation of lateral waves out of an active region of the bulk acoustic resonator. A first electrode is coupled to a first side of a piezoelectric layer and a second electrode is coupled to a second side of the piezoelectric layer to form a stack having the active region. The piezoelectric layer in the active region is configured to resonate in response to an electrical signal applied between the first electrode and the second electrode. One or more perforations in the first electrode, the piezoelectric layer and/or the second electrode, and/or one or more posts or beams supporting the stack, reduce resonance of spurious waves and obstruct propagation of lateral acoustic waves out of the active region.

Film bulk acoustic resonator with spurious resonance suppression

A device including a semiconductor die, a first contact, a second contact, a third contact, a first passivation layer, a second passivation layer and an interconnect metal. The semiconductor die may include a plurality of semiconductor layers disposed on a GaAs substrate. The first contact may be electrically coupled to a semiconductor emitter layer. The second contact may be electrically coupled to a semiconductor base layer. The third contact may be electrically coupled to a semiconductor sub-collector layer. The first passivation layer may cover one or more of the semiconductor and the contacts. The first passivation layer may comprise an inorganic insulator. The second passivation layer may comprise an inorganic insulator or organic polymer with low dielectric constant deposited on the passivation layer. The interconnect metal may be coupled to the first contact and separated from the first passivation layer by the second passivation layer.

Method of making high frequency InGaP/GaAs HBTs

Devices and processes for preparing devices are described for reducing resonance of spurious waves in a bulk acoustic resonator. A first electrode is coupled to a first side of a piezoelectric layer and a second electrode is coupled to a second side of the piezoelectric layer. The piezoelectric layer is configured to resonate in response to an electrical signal applied between the first electrode and the second electrode. Perforations in the first electrode, the piezoelectric layer and/or the second electrode, and/or posts or beams supporting the second electrode, reduce resonance of spurious waves.

A method for fabricating a metal structure for a semiconductor device is disclosed. The method begins with providing a wafer with a current input contact and current output contact. Remaining steps include loading the wafer into a deposition apparatus, depositing a layer of metal onto a predefined metal region, removing the wafer from the deposition apparatus, and performing an ex-situ passivation process. If additional layers are to be deposited and passivated, the steps are repeated until a predetermined number of layers of metal are deposited onto the predefined metal region. The predefined metal region is a gate metal opening if the metal structure is a gate contact for a field effect transistor. The ex-situ passivation process is achievable through oxidation or nitridation of the wafer using either oxygen plasma or a nitrogen plasma, respectively. Alternately, oxidation is also achievable through exposing the wafer to air at an elevated temperature.

Methods for fabricating a metal structure for a semiconductor device

A device includes a semiconductor die. The semiconductor die includes a plurality of semiconductor layers disposed on a GaAs substrate, including a first semiconductor layer having a first band-gap and a second semiconductor layer having a second band-gap. The semiconductor die further includes a contact layer disposed epitaxially upon the first semiconductor layer. The contact layer has a thickness that is less than a critical thickness. The second semiconductor layer is epitaxially disposed upon the contact layer. The contact layer has a third band-gap that is less than the first band-gap and the second band-gap. The semiconductor die further includes a conductive layer disposed upon the contact layer to form an ohmic contact. The conductive layer comprises one or more metal layers compatible with silicon processing techniques.

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Torrance, CA, United States of America

Liping Daniel Hou