Global Communication Semiconductors, LLC

Shing-Kuo Wang

Liping Daniel Hou

Yuefei Yang

Robert Bruce Stokes

Kun-Mao Pan

Alvin M Kong

Dheeraj Mohata

Dae-Jin Hyun

Wing Yau

Alexander M Vigo

Andy Chien-Hsiang Chen

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 semiconductor device includes a semiconductor die, an N-doped region, an N-contact metal, a PN junction mesa, a P-contact metal, a first passivation layer, an anode feed metal, and a cathode feed metal. The semiconductor die may include a plurality of semiconductor layers disposed on an insulating substrate. The N-doped region may define an active area of the device. The N-contact metal may be disposed on a first portion of the N-doped region. The PN junction mesa may be disposed on a second portion of the N-doped region. The PN junction mesa may comprise a hyperabrupt N-doping layer disposed on the first portion of the N-doped region and a P-doped layer disposed on the hyperabrupt N-doping layer. The P-contact metal may be disposed on the P-doped layer of the PN junction mesa. The first passivation layer may cover the semiconductor layers of the semiconductor device and have openings for the N-contact metal and the P-contact metal. The anode feed metal may connect the P-contact metal to a first bond pad. The anode feed metal generally forms an arch from the P-contact metal to the first bond pad and the arch defines a space between the anode feed metal and the first passivation layer covering the semiconductor layers and a the of the PN junction mesa.

Method of making wide tuning range and super low capacitance varactor diodes

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 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.

Gallium arsenide based device having a narrow band-gap semiconductor contact layer

A semiconductor device having a tunable capacitance is disclosed, comprising a substrate, a semiconductor base layer comprising a first semiconductor material having a first band-gap, and a plurality of successive semiconductor layers positioned between the substrate and the semiconductor base layer. The plurality of successive semiconductor layers includes a tuning layer comprising a second semiconductor material having a second band-gap larger than the first band-gap. Furthermore, the tuning layer has a non-uniform doping profile with doping concentration that varies in accordance with distance from a surface of the tuning layer proximal to the semiconductor base layer. The tunable capacitance of the semiconductor device varies in accordance with an applied voltage between the base layer and one of the successive semiconductor layers.

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Torrance, CA, United States of America

Shing-Kuo Wang