Abstract: Device structures for a bipolar junction transistor. A layer is formed on a top surface of a substrate. A trench is formed in the layer and has a plurality of sidewalls with a width between an opposite pair of the sidewalls that varies with increasing distance from the top surface of the substrate. A collector pedestal of the bipolar junction transistor is formed in the trench.

Abstract: Various particular embodiments include a method for forming a photodetector, including: forming a structure including a barrier layer disposed between a layer of doped silicon (Si) and a layer of germanium (Ge), the barrier layer including a crystallization window; and annealing the structure to convert, via the crystallization window, the Ge to a first composition of silicon germanium (SiGe) and the doped Si to a second composition of SiGe.

Abstract: Device structure and fabrication methods for a bipolar junction transistor. A trench isolation region is formed that bounds an active device region along a sidewall. A dielectric region is formed that extends laterally from the sidewall of the active device region into the active device region. The dielectric region is located beneath a top surface of the active device region such that a section of the active device region is located between the top surface and the dielectric region.

Abstract: Photodetector structures and methods of manufacture are provided. The method includes forming undercuts about detector material formed on a substrate. The method further includes encapsulating the detector to form airgaps from the undercuts. The method further includes annealing the detector material causing expansion of the detector material into the airgaps.

Abstract: Disclosed are a method of forming a photodetector and a photodetector structure. In the method, a polycrystalline or amorphous light-absorbing layer is formed on a dielectric layer such that it is in contact with a monocrystalline semiconductor core of an optical waveguide. The light-absorbing layer is then encapsulated in one or more strain-relief layers and a rapid melting growth (RMG) process is performed to crystallize the light-absorbing layer. The strain-relief layer(s) are tuned for controlled strain relief so that, during the RMG process, the light-absorbing layer remains crack-free. The strain-relief layer(s) are then removed and an encapsulation layer is formed over the light-absorbing layer (e.g., filling in surface pits that developed during the RMG process). Subsequently, dopants are implanted through the encapsulation layer to form diffusion regions for PIN diode(s). Since the encapsulation layer is relatively thin, desired dopant profiles can be achieved within the diffusion regions.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: Approaches for silicon photonics integration are provided. A method includes: forming at least one encapsulating layer over and around a photodetector; thermally crystallizing the photodetector material after the forming the at least one encapsulating layer; and after the thermally crystallizing the photodetector material, forming a conformal sealing layer on the at least one encapsulating layer and over at least one device. The conformal sealing layer is configured to seal a crack in the at least one encapsulating layer. The photodetector and the at least one device are on a same substrate. The at least one device includes a complementary metal oxide semiconductor device or a passive photonics device.

Abstract: Fabrication methods for a device structure and device structures. A trench isolation region is formed that bounds an active device region of a semiconductor substrate. A first semiconductor layer is formed on the active device region and on the trench isolation region. A first airgap is formed between the first semiconductor layer and the active device region. A second airgap is formed between the first semiconductor layer and the trench isolation region. The first airgap extends into the active device region such that the height of the first airgap is greater than the height of the second airgap.

Abstract: Embodiments of the present invention include a method for forming a semiconductor emitter and the resulting structure. The invention comprises forming an epitaxial base layer on a semiconductor substrate. A dielectric layer is deposited over the epitaxial base layer. An opening is etched in a portion of the dielectric layer exposing a portion of the epitaxial base layer and a spacer is deposited along the sidewall of the opening. The emitter is grown from the epitaxial base layer to overlap the top surface of the spacer and a portion of the dielectric layer. The single crystal emitter is formed without a mask and without the requirement of subsequent patterning processes.

Abstract: A method of forming a heterojunction bipolar transistor including a field plate. The method may include forming: a substrate having a selectively implanted collector (SIC) and a collector separated by a shallow trench isolation (STI), a field plate in the STI, the field plate extends below a top surface of the SIC, a base layer directly on the SIC, a heterojunction bipolar transistor (HBT) structure above the SIC, the HBT includes an emitter, the emitter is directly on the base layer, a fourth dielectric layer covering the HBT structure, the field plate and the collector, and an emitter contact, a field plate contact and a collector contact extending through the fourth dielectric layer, the emitter contact is in electrical connection with the emitter, the field plate contact is in electrical connection with the field plate and the collector contact is in electrical connection with the collector.

Abstract: Device structures, fabrication methods, and design structures for a bipolar junction transistor. A first isolation region is formed in a substrate to define a lateral boundary for an active device region and an intrinsic base layer is formed on the substrate. The intrinsic base layer has a section overlying the active device region. After the intrinsic base layer is formed, the first isolation region is partially removed adjacent to the active device region to define a trench that is coextensive with the substrate in the active device region and that is coextensive with the first isolation region. The trench is at least partially filled with a dielectric material to define a second isolation region.

Abstract: Device structures for a bipolar junction transistor. A layer is formed on a top surface of a substrate. A trench is formed in the layer and has a plurality of sidewalls with a width between an opposite pair of the sidewalls that varies with increasing distance from the top surface of the substrate. A collector pedestal of the bipolar junction transistor is formed in the trench.

Abstract: Device structures, fabrication methods, and design structures for a bipolar junction transistor. A trench isolation region is formed in a substrate. The trench isolation region is coextensive with a collector in the substrate. A base layer is formed on the collector and on a first portion of the trench isolation region. A dielectric layer is formed on the base layer and on a second portion of the trench isolation region peripheral to the base layer. After the dielectric layer is formed, the trench isolation region is at least partially removed to define an air gap beneath the dielectric layer and the base layer.

Abstract: Disclosed are optoelectronic integrated circuit structures that incorporate a first optical waveguide, having a semiconductor core, indirectly coupled to a grating coupler through a second optical waveguide, having a dielectric core, in order provide a relatively large alignment tolerance. The dielectric core can comprise multiple dielectric layers above one end of the semiconductor core and extending laterally over an isolation region adjacent to that end. The grating coupler can include dielectric fins above the isolation region. Alternatively, the grating coupler can include semiconductor fins within the isolation region. Also disclosed herein are methods of forming such optoelectronic integrated circuit structures that can be readily integrated with complementary metal oxide semiconductor (CMOS) device processing and germanium photodetector processing.

Abstract: Fabrication methods, device structures, and design structures for a bipolar junction transistor. A dielectric structure is formed that is coextensive with a single crystal semiconductor material of a substrate in an active device region. A semiconductor layer is formed that includes a single crystal section coupled with the active device region. The semiconductor layer has an edge that overlaps with a top surface of the dielectric structure. An intrinsic base layer is formed on the semiconductor layer.

Abstract: Device structures and fabrication methods for a bipolar junction transistor. A layer is formed on a top surface of a substrate. A trench is formed in the layer and has a plurality of sidewalls with a width between an opposite pair of the sidewalls that varies with increasing distance from the top surface of the substrate. A collector pedestal of the bipolar junction transistor is formed in the trench.

Abstract: Device structures for a bipolar junction transistor. The device structure includes a collector region, an intrinsic base formed on the collector region, an emitter coupled with the intrinsic base and separated from the collector by the intrinsic base, and an isolation region extending through the intrinsic base to the collector region. The isolation region is formed with a first section having first sidewalls that extend through the intrinsic base and a second section with second sidewalls that extend into the collector region. The second sidewalls are inclined relative to the first sidewalls. The isolation region is positioned in a trench that is formed with first and second etching process in which the latter etches different crystallographic directions of a single-crystal semiconductor material at different etch rates.

Abstract: Photonic SOI devices are formed by lateral epitaxy of a deposited non-crystalline semiconductor layer over a localized buried oxide created by a trench isolation process or by thermal oxidation. Specifically, and after forming a trench into a semiconductor substrate, the trench can be filled with an oxide by a deposition process or a thermal oxidation can be performed to form a localized buried oxide within the semiconductor substrate. In some embodiments, the oxide can be recessed to expose sidewall surfaces of the semiconductor substrate. Next, a non-crystalline semiconductor layer is formed and then a solid state crystallization is preformed which forms a localized semiconductor-on-insulator layer. During the solid state crystallization process portions of the non-crystalline semiconductor layer that are adjacent exposed sidewall surfaces of the substrate are crystallized.

Abstract: Device structures, fabrication methods, and design structures for a bipolar junction transistor. A trench isolation region is formed in a substrate. The trench isolation region is coextensive with a collector in the substrate. A base layer is formed on the collector and on a first portion of the trench isolation region. A dielectric layer is formed on the base layer and on a second portion of the trench isolation region peripheral to the base layer. After the dielectric layer is formed, the trench isolation region is at least partially removed to define an air gap beneath the dielectric layer and the base layer.