Abstract: An optical phase-shifting device includes a ribbed waveguide portion on an insulating layer, the waveguide portion having a p-n or p-i-n junction extending in a longitudinal direction and having a height. A pair of slab portions are disposed adjacent the waveguide portion, one on each side of the ribbed waveguide portion and on the insulation layer. The slab portion have higher doping concentrations than the respective doping concentrations in the ribbed waveguide portion. At least a portion of each slab portion has a height increasing with distance from the waveguide portion, with the slab height being smaller than that of the waveguide portion at the junction between the waveguide portion and slab portion. A pair of contact portions are formed adjacent the respective slab portion and further away from the waveguide portion. A portion of each contact portion can also have a height varying with distance from the waveguide portion.

Abstract: The present disclosure provides a photo sensing device, the photo sensing device includes a substrate, including a silicon layer at a front surface, a photosensitive member extending into and at least partially surrounded by the silicon layer, and a composite layer disposed between the photosensitive member and the silicon layer and surrounding the photosensitive member, wherein the composite layer includes a first material and a second material different from the first material.

Abstract: Integrated optical devices and methods of forming the same are disclosed. A method of forming an integrated optical device includes the following steps. A substrate is provided. The substrate includes, from bottom to top, a first semiconductor layer, an insulating layer and a second semiconductor layer. The second semiconductor layer is patterned to form a waveguide pattern. A surface smoothing treatment is performed to the waveguide pattern until a surface roughness Rz of the waveguide pattern is equal to or less than a desired value. A cladding layer is formed over the waveguide pattern.

Abstract: A photodetector is provided. The photodetector includes a semiconductor layer, a first superlattice structure in the semiconductor layer, and a light absorption material above the first superlattice structure. The first superlattice structure includes vertically stacked pairs of silicon layer/first silicon germanium layer. The first silicon germanium layers are made of Si1-xGex, and x is the atomic percentage of germanium and 0.1?x?0.9.

Abstract: The present disclosure provides a photo sensing device, the photo sensing device includes a substrate, including a silicon layer at a front surface, a photosensitive member extending into and at least partially surrounded by the silicon layer, and a superlattice layer disposed between the photosensitive member and the silicon layer, wherein the superlattice layer includes a first material and a second material different from the first material, a first concentration of the second material at a portion of the superlattice layer proximal to the photosensitive member is greater than a second concentration of the second material at a portion of the superlattice layer distal to the photosensitive member.

Abstract: An optical system with different optical coupling device configurations and a method of fabricating the same are disclosed. An optical system includes a substrate, a waveguide disposed on the substrate, an optical fiber optically coupled to the waveguide, and an optical coupling device disposed between the optical fiber and the waveguide. The optical coupling device configured to optically couple the optical fiber to the waveguide. The optical coupling device includes a dielectric layer disposed on the substrate, a semiconductor tapered structure disposed in a first horizontal plane within the dielectric layer, and a multi-tip dielectric structure disposed in a second horizontal plane within the dielectric layer.

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: Semiconductor package structures are provided. An interposer is bonded to a printed circuit board (PCB) or package substrate through first solder bumps disposed on a first side of the interposer. The first solder bumps have a first pitch. A plurality of semiconductor chips are formed, and each of the semiconductor chips is bonded to a second side of the interposer through second solder bumps. The second solder bumps have a second pitch that is less than the first pitch. Each of the semiconductor chips includes a substrate with one or more transistors or integrated circuits formed thereon.

Abstract: An optical device for coupling light propagating between a waveguide and an optical transmission component is provided. The optical device including a taper portion and a grating portion. The grating portion is connected to the taper portion. The grating portion includes grating patterns. Ends of the grating patterns are separated from an outer edge of the optical device by a distance.

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: A directional coupler is configured to receive a continuous light waveform and split the waveform into two carrier signals. Ring modulators are configured to receive the carrier signals and binary data and modulate the carrier signals based on the binary data. A combiner is configured to combine the modulated carrier signals into a four-level pulse amplitude modulation (PAM4) signal.

Abstract: A photonic structure is provided. The photonic structure includes a first oxide layer in a semiconductor substrate, a second oxide layer over an upper surface of the semiconductor substrate and an upper surface of the first oxide layer, and an optical coupling region over an upper surface of the second oxide layer. The optical coupling region is made of silicon, and an area of the optical coupling region is confined within an area of the first oxide layer in a plan view.

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 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 second waveguide feature and a portion of the second waveguide feature vertically overlaps a portion of the first waveguide feature.

Abstract: A circuit includes a temperature-sensitive voltage divider. The temperature-sensitive voltage divider includes a temperature-sensitive resistor and a second resistor having a first terminal coupled to a first terminal of the temperature-sensitive resistor. A temperature signal is generated at a first node coupled to the first terminal of the temperature-sensitive resistor. Detection logic is coupled to the first node to generate a detection signal responsive to the temperature signal.

Abstract: Apparatus and circuits including transistors with different gate stack materials and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; a channel layer formed over the substrate; a first transistor formed over the channel layer, wherein the first transistor comprises a first source region, a first drain region, a first gate structure, and a first polarization modulation portion under the first gate structure; and a second transistor formed over the channel layer, wherein the second transistor comprises a second source region, a second drain region, a second gate structure, and a second polarization modulation portion under the second gate structure, wherein the first polarization modulation portion is made of a material different from that of the second polarization modulation portion.

Abstract: A photonic structure is provided. The photonic structure includes a semiconductor substrate, a buried oxide layer over the semiconductor substrate, an optical coupling region over the buried oxide layer, and an oxide structure embedded in the semiconductor substrate. The optical coupling region is tapered toward a terminus of the optical coupling region located at an edge of the semiconductor substrate. The optical coupling region overlaps the oxide structure in a plan view.

Abstract: An optical phase-shifting device includes a ribbed waveguide portion on an insulating layer, the waveguide portion having a p-n or p-i-n junction extending in a longitudinal direction and having a height. A pair of slab portions are disposed adjacent the waveguide portion, one on each side of the ribbed waveguide portion and on the insulation layer. The slab portion have higher doping concentrations than the respective doping concentrations in the ribbed waveguide portion. At least a portion of each slab portion has a height increasing with distance from the waveguide portion, with the slab height being smaller than that of the waveguide portion at the junction between the waveguide portion and slab portion. A pair of contact portions are formed adjacent the respective slab portion and further away from the waveguide portion. A portion of each contact portion can also have a height varying with distance from the waveguide portion.

Abstract: A gallium nitride-on-silicon structure is disclosed in which the two-dimensional electron gas (2DEG) layer is a discontinuous layer that includes at least two 2DEG segments. Each 2DEG segment is separated from another 2DEG segment by a gap. The 2DEG layer can be depleted by a p-doped gallium nitride layer that is disposed over a portion of an aluminum gallium nitride layer. Additionally or alternatively, a trench may be formed in the structure through the 2DEG layer to produce a gap in the 2DEG layer. An electrical component is positioned over at least a portion of a gap.

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.