Abstract: Structures including an electro-absorption modulator and methods of forming such structures. The structure comprises a waveguide core including a first tapered section, a second tapered section, and a longitudinal axis. The first tapered section and the second tapered section are aligned along the longitudinal axis. The structure further comprises a first waveguide taper overlapping the first tapered section of the waveguide core, a second waveguide taper overlapping the second tapered section of the waveguide core, and a multiple-layer structure on the waveguide core between the first waveguide taper and the second waveguide taper.

Abstract: Structures including a vertical heterojunction bipolar transistor and methods of forming a structure including a vertical heterojunction bipolar transistor. The structure comprises a semiconductor substrate including a trench, a first semiconductor layer including a portion adjacent to the trench, a dielectric layer between the first semiconductor layer and the semiconductor substrate, and a second semiconductor layer in the trench. The dielectric layer has an interface with the first semiconductor layer, and the second semiconductor layer includes a portion that is recessed relative to the interface. The structure further comprises a vertical heterojunction bipolar transistor including a collector in the portion of the second semiconductor layer.

Abstract: Structures for an ion-sensitive field-effect transistor and methods of forming same. The structure comprises a semiconductor substrate, a microfluidic channel above the semiconductor substrate, a semiconductor layer including a portion positioned as a sensing layer in the microfluidic channel, a first electrical connection coupled to the portion of the semiconductor layer, and a second electrical connection coupled to the semiconductor substrate. The portion of the semiconductor layer is spaced above the semiconductor substrate.

Abstract: Structures including an electro-absorption modulator and methods of forming such structures. The structure comprises a waveguide core including a first tapered section, a second tapered section, and a longitudinal axis. The first tapered section and the second tapered section are aligned along the longitudinal axis. The structure further comprises a first waveguide taper overlapping the first tapered section of the waveguide core, a second waveguide taper overlapping the second tapered section of the waveguide core, and a multiple-layer structure on the waveguide core between the first waveguide taper and the second waveguide taper.

Abstract: Structures for a bipolar junction transistor and methods of forming a structure for a bipolar junction transistor. The structure includes a first terminal having a first raised semiconductor layer on a semiconductor substrate, a second terminal having a second raised semiconductor layer on the semiconductor substrate, and an intrinsic base on the semiconductor substrate. The intrinsic base is positioned in a lateral direction between the first raised semiconductor layer of the first terminal and the second raised semiconductor layer of the second terminal. The intrinsic base includes a portion containing silicon-germanium with a germanium concentration that is graded in the lateral direction.

Abstract: Structures for a bipolar junction transistor and methods of forming a structure for a bipolar junction transistor. The structure includes a dielectric layer having a cavity, a first semiconductor layer on the dielectric layer, a collector including a portion on the first semiconductor layer, an emitter including a portion on the first semiconductor layer, and a second semiconductor layer that includes a first section in the cavity and a second section. The second section of the second semiconductor layer is laterally positioned between the portion of the collector and the portion of the emitter.

Abstract: Structures including a vertical heterojunction bipolar transistor and methods of forming a structure including a vertical heterojunction bipolar transistor. The structure comprises a semiconductor substrate including a trench, a first semiconductor layer including a portion adjacent to the trench, a dielectric layer between the first semiconductor layer and the semiconductor substrate, and a second semiconductor layer in the trench. The dielectric layer has an interface with the first semiconductor layer, and the second semiconductor layer includes a portion that is recessed relative to the interface. The structure further comprises a vertical heterojunction bipolar transistor including a collector in the portion of the second semiconductor layer.

Abstract: Waveguide structures and methods of fabricating a waveguide structure. The structure includes a first waveguide core, a second waveguide core, and a third waveguide core adjacent to the first waveguide core and the second waveguide core. The third waveguide core is laterally separated from the first waveguide core by a first slot, and the third waveguide core is laterally separated from the second waveguide core by a second slot. The first waveguide core and the second waveguide core comprise a first material, and the third waveguide core comprises a second material that is different in composition from the first material.

Abstract: Photonics structures including an optical component and methods of fabricating a photonics structure including an optical component. The photonics structure includes an optical component, a substrate having a cavity and a dielectric material in the cavity, and a dielectric layer positioned in a vertical direction between the optical component and the cavity. The optical component is positioned in a lateral direction to overlap with the cavity in the substrate.

Abstract: Structures for a bipolar junction transistor and methods of forming a structure for a bipolar junction transistor. The structure includes a first terminal having a first raised semiconductor layer on a semiconductor substrate, a second terminal having a second raised semiconductor layer on the semiconductor substrate, and an intrinsic base on the semiconductor substrate. The intrinsic base is positioned in a lateral direction between the first raised semiconductor layer of the first terminal and the second raised semiconductor layer of the second terminal. The intrinsic base includes a portion containing silicon-germanium with a germanium concentration that is graded in the lateral direction.

Abstract: Photonics structures including an optical component and methods of fabricating a photonics structure including an optical component. The photonics structure includes an optical component, a substrate having a cavity and a dielectric material in the cavity, and a dielectric layer positioned in a vertical direction between the optical component and the cavity. The optical component is positioned in a lateral direction to overlap with the cavity in the substrate.

Abstract: Waveguide structures and methods of fabricating a waveguide structure. The structure includes a first waveguide core, a second waveguide core, and a third waveguide core adjacent to the first waveguide core and the second waveguide core. The third waveguide core is laterally separated from the first waveguide core by a first slot, and the third waveguide core is laterally separated from the second waveguide core by a second slot. The first waveguide core and the second waveguide core comprise a first material, and the third waveguide core comprises a second material that is different in composition from the first material.

Abstract: Structures for a bipolar junction transistor and methods of forming a structure for a bipolar junction transistor. The structure includes a dielectric layer having a cavity, a first semiconductor layer on the dielectric layer, a collector including a portion on the first semiconductor layer, an emitter including a portion on the first semiconductor layer, and a second semiconductor layer that includes a first section in the cavity and a second section. The second section of the second semiconductor layer is laterally positioned between the portion of the collector and the portion of the emitter.

Abstract: Structures for a grating coupler and methods of fabricating a structure for a grating coupler. The structure includes a grating coupler having a central portion and edge portions. The central portion and the edge portions define a sidewall, and the central portion and the edge portions have a first longitudinal axis along which the edge portions are arranged in a spaced relationship. Each edge portion projects from the sidewall at an angle relative to the first longitudinal axis. A waveguide core is optically coupled to the grating coupler. The first longitudinal axis is aligned in a first direction, and the waveguide core has a second longitudinal axis that is aligned in a second direction different from the first direction.

Abstract: Structures for a photodetector and methods of fabricating a structure for a photodetector. A photodetector may have a light-absorbing layer comprised of germanium. A waveguide core may be coupled to the light-absorbing layer. The waveguide core may be comprised of a dielectric material, such as silicon nitride. Another waveguide core, which may be comprised of a different material such as single-crystal silicon, may be coupled to the light-absorbing layer.

Abstract: Structures for a photodetector and methods of fabricating a structure for a photodetector. A photodetector may have a light-absorbing layer comprised of germanium. A waveguide core may be coupled to the light-absorbing layer. The waveguide core may be comprised of a dielectric material, such as silicon nitride. Another waveguide core, which may be comprised of a different material such as single-crystal silicon, may be coupled to the light-absorbing layer.

Abstract: Structures for a field-effect transistor and methods of forming a structure for a field-effect transistor. First and second gate structures extend over the semiconductor body. A source/drain region is positioned laterally between the first gate structure and the second gate structure. The source/drain region includes a semiconductor layer having a first section, a second section, and a third section. A first portion of the semiconductor body is positioned between the first section of the semiconductor layer and the second section of the semiconductor layer. A second portion of the semiconductor body is positioned between the second section of the semiconductor layer and the third section of the semiconductor layer.

Abstract: Structures for a field-effect transistor and methods of forming a structure for a field-effect transistor. First and second gate structures extend over the semiconductor body. A source/drain region is positioned laterally between the first gate structure and the second gate structure. The source/drain region includes a semiconductor layer having a first section, a second section, and a third section. A first portion of the semiconductor body is positioned between the first section of the semiconductor layer and the second section of the semiconductor layer. A second portion of the semiconductor body is positioned between the second section of the semiconductor layer and the third section of the semiconductor layer.

Abstract: Structures for a field-effect transistor and methods of forming a structure for a field-effect transistor. First and second gate structures extend over the semiconductor body, a second gate structure that extends over the semiconductor body. A source/drain region is positioned laterally between the first gate structure and the second gate structure. The source/drain region includes a first semiconductor layer and a second semiconductor layer. The first semiconductor layer has a first section and a second section. The second semiconductor layer is positioned laterally between the first section of the first semiconductor layer and the second section of the first semiconductor layer.

Abstract: Structures for a heterojunction bipolar transistor and methods of forming a structure for a heterojunction bipolar transistor. A base layer is positioned in a cavity in a semiconductor layer, a first terminal is coupled to the base layer, and a second terminal is coupled to a portion of the semiconductor layer. The second terminal is laterally spaced from the first terminal, and the portion of the semiconductor layer is laterally positioned between the second terminal and the base layer.