Abstract: A junction field effect transistor (JFET) structure includes a doped polysilicon gate over a channel region of a semiconductor layer. The doped polysilicon gate has a first doping type. A raised epitaxial source is on the source region of the semiconductor layer and adjacent a first sidewall of the doped polysilicon gate, and has a second doping type opposite the first doping type. A raised epitaxial drain is on the drain region of the semiconductor layer and adjacent a second sidewall of the doped polysilicon gate, and has the second doping type. A doped semiconductor region is within the channel region of the semiconductor layer and extending from the source region to the drain region, and a non-conductive portion of the semiconductor layer is within the channel region to separate the doped semiconductor region from the doped polysilicon gate.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to heterojunction bipolar transistors and methods of manufacture. The structure includes a collector region composed of semiconductor material; at least one marker layer over the collector region; a layer of doped semiconductor material which forms an extrinsic base and which is located above the at least one marker layer; a cavity formed in the layer of doped semiconductor material and extending at least to the at least one marker layer; an epitaxial intrinsic base layer of doped material located within the cavity; and an emitter material over the epitaxial intrinsic base layer and within an opening formed by sidewall spacer structures.

Abstract: Transistor-based sensors and fabrication methods for a transistor-based sensor. A semiconductor layer is arranged over a substrate, and an interconnect structure is arranged over the semiconductor layer and the substrate. The semiconductor layer includes first sections composed of a semiconductor material, second sections composed of the semiconductor material, and cavities. The first sections have an alternating arrangement with the second sections in a lateral direction. The semiconductor material of the first sections is polycrystalline, and the semiconductor material of the second sections is single-crystal. First and second openings each extend in a vertical direction through the metallization levels of the interconnect structure to the semiconductor layer or through the substrate to the semiconductor layer. The first opening defines a first fluid inlet coupled to the cavities, and the second opening defines a first fluid outlet coupled to the cavities.

Abstract: Device structures and fabrication methods for a bipolar junction transistor. A trench isolation region surrounds an active region that includes a collector. A base layer includes a first section and a second section that are located over the active region. An emitter is positioned on the first section of the base layer, and an extrinsic base layer is positioned on the second section of the base layer. The extrinsic base layer has a side surface adjacent to the emitter. The side surface of the extrinsic base layer is inclined relative to a top surface of the base layer in a direction away from the emitter.

Abstract: Structures for transistor-based sensors and related fabrication methods. A layer stack is formed that includes a semiconductor layer and a cavity. A transistor is formed that has a gate electrode over the layer stack, and an interconnect structure is formed over the layer stack and the transistor. First and second openings are formed that extend through the metallization levels of the interconnect structure and the semiconductor layer to the cavity. The first opening defines a fluid inlet coupled to the cavity, and the second opening defines a fluid outlet coupled to the cavity.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to a switch with local silicon on insulator (SOI) and deep trench isolation structures and methods of manufacture. The structure a structure comprises an air gap located under a device region and bounded by an upper etch stop layer and deep trench isolation structures.

Abstract: Fabrication methods and device structures for a heterojunction bipolar transistor. A trench isolation region is formed that surrounds an active region of semiconductor material, a collector is formed in the active region, and a base layer is deposited that includes a first section over the trench isolation region, a second section over the active region, and a third section over the active region that connects the first section and the second section. An emitter is arranged over the second section of the base layer, and an extrinsic base layer is arranged over the first section of the base layer and the third section of the base layer. The extrinsic base layer includes a first section containing polycrystalline semiconductor material and a second section containing single-crystal semiconductor material. The first and second sections of the extrinsic base layer intersect along an interface that extends over the trench isolation region.

Abstract: A tunable breakdown voltage RF MESFET and/or MOSFET and methods of manufacture are disclosed. The method includes forming a first line and a second line on an underlying gate dielectric material. The second line has a width tuned to a breakdown voltage. The method further includes forming sidewall spacers on sidewalls of the first and second line such that the space between first and second line is pinched-off by the dielectric spacers. The method further includes forming source and drain regions adjacent outer edges of the first line and the second line, and removing at least the second line to form an opening between the sidewall spacers of the second line and to expose the underlying gate dielectric material. The method further includes depositing a layer of material on the underlying gate dielectric material within the opening, and forming contacts to a gate structure and the source and drain regions.

Abstract: A tunable breakdown voltage RF MESFET and/or MOSFET and methods of manufacture are disclosed. The method includes forming a first line and a second line on an underlying gate dielectric material. The second line has a width tuned to a breakdown voltage. The method further includes forming sidewall spacers on sidewalls of the first and second line such that the space between first and second line is pinched-off by the dielectric spacers. The method further includes forming source and drain regions adjacent outer edges of the first line and the second line, and removing at least the second line to form an opening between the sidewall spacers of the second line and to expose the underlying gate dielectric material. The method further includes depositing a layer of material on the underlying gate dielectric material within the opening, and forming contacts to a gate structure and the source and drain regions.

Abstract: A method includes forming a base layer on a top surface of a substrate. A dielectric layer is formed on exposed surfaces of the base layer. A hardmask layer is formed on the base layer and the dielectric layer. A pattern is formed from the hardmask with a first opening and a second opening. Portions of a dielectric layer are removed from the top surface of the base layer at positions consistent with the pattern of the first opening and the second opening to form exposed surfaces defined as a first window and a second window in the dielectric layer. Deposits of a dopant-containing layer are limited on the exposed surfaces of: a first portion on the top surface of the base layer inside of the first window, and a second portion on the top surface of the base layer inside of the second window.

Abstract: Transistor-based sensors and fabrication methods for a transistor-based sensor. A semiconductor layer is arranged over a substrate, and an interconnect structure is arranged over the semiconductor layer and the substrate. The semiconductor layer includes first sections composed of a semiconductor material, second sections composed of the semiconductor material, and cavities. The first sections have an alternating arrangement with the second sections in a lateral direction. The semiconductor material of the first sections is polycrystalline, and the semiconductor material of the second sections is single-crystal. First and second openings each extend in a vertical direction through the metallization levels of the interconnect structure to the semiconductor layer or through the substrate to the semiconductor layer. The first opening defines a first fluid inlet coupled to the cavities, and the second opening defines a first fluid outlet coupled to the cavities.

Abstract: Device structures and fabrication methods for a bipolar junction transistor. A trench isolation region surrounds an active region that includes a collector. A base layer is arranged over the active region, and a semiconductor layer is arranged on the base layer. The semiconductor layer includes a stepped profile with a first section having a first width adjacent to the base layer and a second section having a second width that is less than the first width. An emitter is arranged on the second section of the semiconductor layer.

Abstract: A tunable breakdown voltage RF MESFET and/or MOSFET and methods of manufacture are disclosed. The method includes forming a first line and a second line on an underlying gate dielectric material. The second line has a width tuned to a breakdown voltage. The method further includes forming sidewall spacers on sidewalls of the first and second line such that the space between first and second line is pinched-off by the dielectric spacers. The method further includes forming source and drain regions adjacent outer edges of the first line and the second line, and removing at least the second line to form an opening between the sidewall spacers of the second line and to expose the underlying gate dielectric material. The method further includes depositing a layer of material on the underlying gate dielectric material within the opening, and forming contacts to a gate structure and the source and drain regions.

Abstract: A field effect transistor (FET) with an underlying airgap and methods of manufacture are disclosed. The method includes forming an amorphous layer at a predetermined depth of a substrate. The method further includes forming an airgap in the substrate under the amorphous layer. The method further includes forming a completely isolated transistor in an active region of the substrate, above the amorphous layer and the airgap.

Abstract: A tunable breakdown voltage RF MESFET and/or MOSFET and methods of manufacture are disclosed. The method includes forming a first line and a second line on an underlying gate dielectric material. The second line has a width tuned to a breakdown voltage. The method further includes forming sidewall spacers on sidewalls of the first and second line such that the space between first and second line is pinched-off by the dielectric spacers. The method further includes forming source and drain regions adjacent outer edges of the first line and the second line, and removing at least the second line to form an opening between the sidewall spacers of the second line and to expose the underlying gate dielectric material. The method further includes depositing a layer of material on the underlying gate dielectric material within the opening, and forming contacts to a gate structure and the source and drain regions.

Abstract: A tunable breakdown voltage RF MESFET and/or MOSFET and methods of manufacture are disclosed. The method includes forming a first line and a second line on an underlying gate dielectric material. The second line has a width tuned to a breakdown voltage. The method further includes forming sidewall spacers on sidewalls of the first and second line such that the space between first and second line is pinched-off by the dielectric spacers. The method further includes forming source and drain regions adjacent outer edges of the first line and the second line, and removing at least the second line to form an opening between the sidewall spacers of the second line and to expose the underlying gate dielectric material. The method further includes depositing a layer of material on the underlying gate dielectric material within the opening, and forming contacts to a gate structure and the source and drain regions.

Abstract: Device structures and fabrication methods for a bipolar junction transistor. A trench isolation region surrounds an active region that includes a collector. A base layer is arranged over the active region, and a semiconductor layer is arranged on the base layer. The semiconductor layer includes a stepped profile with a first section having a first width adjacent to the base layer and a second section having a second width that is less than the first width. An emitter is arranged on the second section of the semiconductor layer.

Abstract: Lateral PiN diodes and Schottky diodes with low parasitic capacitance and variable breakdown voltage structures and methods of manufacture are disclosed. The structure includes a diode with breakdown voltage determined by a dimension between p-and n-terminals formed in an i-region above a substrate.

Abstract: A method includes forming a base layer on a top surface of a substrate. A dielectric layer is formed on exposed surfaces of the base layer. A hardmask layer is formed on the base layer and the dielectric layer. A pattern is formed from the hardmask with a first opening and a second opening. Portions of a dielectric layer are removed from the top surface of the base layer at positions consistent with the pattern of the first opening and the second opening to form exposed surfaces defined as a first window and a second window in the dielectric layer. Deposits of a dopant-containing layer are limited on the exposed surfaces of: a first portion on the top surface of the base layer inside of the first window, and a second portion on the top surface of the base layer inside of the second window.

Abstract: A device structure for a bipolar junction transistor includes a base layer made of a semiconductor material. An emitter is disposed on a first portion of the base layer. A dopant-containing layer is disposed on a second portion of the base layer. A hardmask is disposed on the base layer. The hardmask includes a window aligned with the second portion of the base layer. Deposits of the dopant-containing layer are limited to exposed surfaces of: the first portion that is disposed on a top surface of the base layer inside of the window.