Abstract: The semiconductor structure includes a substrate. The semiconductor structure further includes a channel layer over the substrate. The semiconductor structure further includes an active layer over the channel layer, wherein the active layer has a different composition from the channel layer. The active layer includes a first region having a first thickness, and a second region having a second thickness, wherein the second region is continuous with the first region. The semiconductor structure further includes a first transistor over the first region; and a second transistor over the second region.

Abstract: An optical device for coupling light propagating between a waveguide and an optical transmission component is provided. The optical device includes a taper portion and a grating portion. The taper portion is disposed between the grating portion and the waveguide. The grating portion includes rows of grating patterns. A first size of a first grating pattern in a first row of grating patterns is larger than a second size of a second grating pattern in a second row of grating patterns. A first distance between the first row of grating patterns and the waveguide is less than a second distance between the second row of grating patterns and the waveguide.

Abstract: A method includes bonding a III-V die directly to a Complementary Metal-Oxide-Semiconductor (CMOS) die to form a die stack. The III-V die includes a (111) semiconductor substrate, and a first circuit including a III-V based n-type transistor formed at a surface of the (111) semiconductor substrate. The CMOS die includes a (100) semiconductor substrate, and a second circuit including an n-type transistor and a p-type transistor on the (100) semiconductor substrate. The first circuit is electrically connected to the second circuit.

Abstract: Systems, methods, and devices are described herein for generating a pulse width modulation (PWM) signal having a specific duty cycle. In one embodiment, the system includes a square wave generator and a logic device. The square wave generator is configured to delay a input square wave signal to generate a plurality of square wave signals. The logic device is configured to perform a logic operation to two of square wave signals of the plurality of square wave signals, which in turn generates the PWM signal having a duty cycle corresponding to the two square wave signals.

Abstract: Apparatus and circuits including transistors with different threshold voltages and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; an active layer that is formed over the substrate and comprises a plurality of active portions; a polarization modulation layer comprising a plurality of polarization modulation portions each of which is disposed on a corresponding one of the plurality of active portions; and a plurality of transistors each of which comprises a source region, a drain region, and a gate structure formed on a corresponding one of the plurality of polarization modulation portions. The transistors have at least three different threshold voltages.

Abstract: Apparatus and circuits with dual threshold voltage transistors and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; a first layer comprising a first III-V semiconductor material formed over the substrate; a first transistor formed over the first layer, and a second transistor formed over the first layer. The first transistor comprises a first gate structure comprising a first material, a first source region and a first drain region. The second transistor comprises a second gate structure comprising a second material, a second source region and a second drain region. The first material is different from the second material.

Abstract: A driving circuit includes a driving stage, and a first subcircuit. The driving stage includes a first driving device and a second driving device configured to drive a power device. The first subcircuit is electrically connected to the driving stage. The first subcircuit includes a first precharge circuit and a first predriving circuit. The first predriving circuit is electrically connected to the first precharge circuit and the first driving device. The first precharge circuit is configured to, in response to an input signal of the driving circuit having a first signal level, generate a first precharging voltage. The first precharge circuit is further configured to, in response to the input signal having a second signal level different from the first signal level, fully turn on, based on the first precharging voltage, a first predriving device in the first predriving circuit to drive the first driving device.

Abstract: An optical device for coupling light propagating between a waveguide and an optical transmission component is provided. The optical device includes a taper portion and a grating portion. The taper portion is disposed between the grating portion and the waveguide. The grating portion includes rows of grating patterns. A first size of a first grating pattern in a first row of grating patterns is larger than a second size of a second grating pattern in a second row of grating patterns. A first distance between the first row of grating patterns and the waveguide is less than a second distance between the second row of grating patterns and the waveguide.

Abstract: An integrated circuit includes a first circuit, formed based on one or more Group III-V compound materials, that is configured to operate with a first voltage range. The integrated circuit includes a second circuit, also formed based on the one or more Group III-V compound materials, that is operatively coupled to the first circuit and configured to operate with a second voltage range, wherein the second voltage range is substantially higher than the first voltage range. The integrated circuit includes a set of first test terminals connected to the first circuit. The integrated circuit includes a set of second test terminals connected to the second circuit. Test signals applied to the set of first test terminals and to the set of second test terminals, respectively, are independent from each other.

Abstract: A semiconductor structure according to the present disclosure includes a buried oxide layer, a first dielectric layer disposed over the buried oxide layer, a first waveguide feature disposed in the first dielectric layer, a second dielectric layer disposed over the first dielectric layer and the first waveguide feature, a third dielectric layer disposed over the second dielectric layer, and a second waveguide feature disposed in the second dielectric layer and the third dielectric layer. The second waveguide feature is disposed over the first waveguide feature and a portion of the second waveguide feature vertically overlaps a portion of the first waveguide feature.

Abstract: Apparatus and circuits including transistors with different polarizations and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; an active layer that is formed over the substrate and comprises a first active portion and a second active portion; a first transistor comprising a first source region, a first drain region, and a first gate structure formed over the first active portion and between the first source region and the first drain region; and a second transistor comprising a second source region, a second drain region, and a second gate structure formed over the second active portion and between the second source region and the second drain region, wherein the first active portion has a material composition different from that of the second active portion.

Abstract: A semiconductor device include: a first bus waveguide; a first silicon ring optically coupled to the first bus waveguide; a backup silicon ring optically coupled to the first bus waveguide; a first heater and a second heater configured to heat the first silicon ring and the backup silicon ring, respectively; and a first switch, where the first switch is configured to electrically couple the first silicon ring to a first radio frequency (RF) circuit when the first switch is at a first switching position, and is configured to electrically couple the backup silicon ring to the first RF circuit when the first switch is at a second switching position.

Abstract: An apparatus and method for testing gallium nitride field effect transistors (GaN FETs) are disclosed herein. In some embodiments, the apparatus includes: a high side GaN FET, a low side GaN FET, a high side driver coupled to a gate of the high side GaN FET, a low side driver coupled to a gate of the low side GaN FET, and a driver circuit coupled to the high side and low side drivers and configured to generate drive signals capable of driving the high and low side GaN FETs, wherein the high and low side GaN FETs and transistors, within the high and low side drivers and the driver circuit, are patterned on a same semiconductor device layer during a front-end-of-line (FEOL) process.

Abstract: This disclosure is directed to a circuit that includes a substrate, a target device on the substrate, and an electrostatic discharge (ESD) device electrically coupled to the target device. The ESD device includes an ESD detection circuit electrically coupled to a first reference voltage supply and a second reference voltage supply, an inverter circuit electrically coupled to the ESD detection circuit and configured to trigger in response to an ESD event on the first or second reference voltage supply, a rectifier circuit electrically coupled to the inverter circuit and configured to rectify a current discharged from the inverter circuit, and a transistor electrically coupled to the rectifier circuit and configured to discharge a remaining current passing through the rectifier circuit.

Abstract: Various embodiments of the present disclosure are directed towards a semiconductor package structure including a first integrated circuit (IC) chip overlying a base structure. An electrical IC chip overlies the base structure and is disposed around the first IC chip. The electrical IC chip is electrically coupled to the first IC chip. A photonic IC chip overlies the base structure and is electrically coupled to the electrical IC chip. The photonic IC chip is configured to receive an input optical signal. The photonic IC chip is adjacent to the electrical IC chip.

Abstract: Apparatus and circuits with dual threshold voltage transistors and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; a first layer comprising a first III-V semiconductor material formed over the substrate; a first transistor formed over the first layer, and a second transistor formed over the first layer. The first transistor comprises a first gate structure comprising a first material, a first source region and a first drain region. The second transistor comprises a second gate structure comprising a second material, a second source region and a second drain region. The first material is different from the second material.

Abstract: Methods of fabricating optical devices with high refractive index materials are disclosed. The method includes forming a first oxide layer on a substrate and forming a patterned template layer with first and second trenches on the first oxide layer. A material of the patterned template layer has a first refractive index. The method further includes forming a first portion of a waveguide and a first portion of an optical coupler within the first and second trenches, respectively, forming a second portion of the waveguide and a second portion of the optical coupler on a top surface of the patterned template layer, and depositing a cladding layer on the second portions of the waveguide and optical coupler. The waveguide and the optical coupler include materials with a second refractive index that is greater than the first refractive index.

Abstract: The present disclosure provides a photo sensing device and a method for forming a photo sensing device. The photo sensing device includes a substrate, a photosensitive member, a superlattice layer and a diffusion barrier structure. The substrate includes a silicon layer at a front surface. The photosensitive member extends into and at least partially surrounded by the silicon layer, wherein an upper portion of the photosensitive member protruding from the silicon layer has a top surface and a facet tapering toward the top surface. The superlattice layer is disposed between the photosensitive member and the silicon layer. The diffusion barrier structure is disposed at a first side of the photosensitive member and a bottom of the diffusion barrier structure is at a level below a top surface of the silicon layer, wherein at least a portion of the diffusion barrier structure is laterally surrounded by the silicon layer.

Abstract: An integrated circuit includes a first circuit, formed based on one or more Group III-V compound materials, that is configured to operate with a first voltage range. The integrated circuit includes a second circuit, also formed based on the one or more Group III-V compound materials, that is operatively coupled to the first circuit and configured to operate with a second voltage range, wherein the second voltage range is substantially higher than the first voltage range. The integrated circuit includes a set of first test terminals connected to the first circuit. The integrated circuit includes a set of second test terminals connected to the second circuit. Test signals applied to the set of first test terminals and to the set of second test terminals, respectively, are independent from each other.

Abstract: The present disclosure describes a semiconductor device having artificial field plates. The semiconductor device includes a first gallium nitride (GaN) layer on a substrate, an aluminum gallium nitride (AlGaN) layer on the first GaN layer, and a second GaN layer on the AlGaN layer. The first and second GaN layers includes different types of dopants. The semiconductor device further includes a gate contact structure in contact with the second GaN layer, first and second source/drain (S/D) contact structures in contact with the AlGaN layer, one or more artificial field plates between the gate contact structure and the first S/D contact structure. The first and second S/D contact structures are disposed at opposite sides of the gate contact structure. The one or more artificial field plates are separated from the first and second S/D contact structures and above the AlGaN layer.