Embodiments of the disclosure provide a crystalline semiconductor layer between a bipolar transistor structure and a field effect transistor (FET) structure. The structure includes a dielectric layer on a back-gate semiconductor layer, a bipolar transistor structure on the dielectric layer, FET structure on the dielectric layer, and a crystalline semiconductor layer on the dielectric layer between the bipolar transistor structure and the FET structure. The crystalline semiconductor layer includes a terminal of the bipolar transistor structure and a terminal of the FET structure.

Gate-all-around integrated circuit structures having devices with channel-to-substrate electrical contact are described. For example, an integrated circuit structure includes a first vertical arrangement of horizontal nanowires above a first fin. A channel region of the first vertical arrangement of horizontal nanowires is electrically coupled to the first fin by a semiconductor material layer directly between the first vertical arrangement of horizontal nanowires and the first fin. A first gate stack is over the first vertical arrangement of horizontal nanowires. A second vertical arrangement of horizontal nanowires is above a second fin. A channel region of the second vertical arrangement of horizontal nanowires is electrically isolated from the second fin. A second gate stack is over the second vertical arrangement of horizontal nanowires.

Disclosed examples include integrated circuits and bipolar transistors with a first region of a first conductivity type in a substrate, a collector region of a second conductivity type disposed in the substrate, and a base region of the first conductivity type extending into the first region. A first emitter region of the second conductivity type extends into the first region and includes a lateral side spaced from and facing the base region. A second emitter region of the second conductivity type extends downward into the first region, abutting the top surface and an upper portion of the first lateral side of the first emitter region to mitigate surface effects and gain degradation caused by hydrogen injection from radiation to provide a radiation hardened bipolar transistor.

A semiconductor device may include a well region disposed in a substrate, an impurity injection region disposed in the well region, an active fin on the well region, a lower insulating layer covering the impurity injection region and the active fin, and a connection pattern provided to penetrate the active fin and connected to the well region. The substrate and the impurity injection region may have a first conductivity type, and the well region may have a second conductivity type different from the first conductivity type. An uppermost portion of the impurity injection region may be in direct contact with the lower insulating layer.

Structures for a heterojunction bipolar transistor and methods of forming a structure for a heterojunction bipolar transistor. The structure comprises an intrinsic base including a first semiconductor layer, a collector including a second semiconductor layer, and an emitter including a third semiconductor layer. The first semiconductor layer, which comprises silicon-germanium, includes a first portion and a second portion adjacent to the first portion. The second semiconductor layer includes a portion on the first portion of the first semiconductor layer, and the third semiconductor layer includes a portion on the second portion of the first semiconductor layer. The structure further comprises a dielectric spacer laterally between the portion of the second semiconductor layer and the portion of the third semiconductor layer.

A bipolar transistor is capable of reducing variations in electrical characteristics. A bipolar transistor 100 includes: a collector region 150 which is a predetermined region in a P-type semiconductor substrate 110; a base region 140 which is formed within the collector region 150 and is an N-type well region; a polysilicon 130 formed on the base region 140 via an insulating film 131 and having an outer periphery, as viewed in a plan view, in a rectangular ring shape; and a P-type emitter region 120 surrounded by the polysilicon 130 and formed within the base region 140. The polysilicon 130 includes an extension portion 130a extending inside a contact region 141 of the base region 140 and electrically connected to the base region 140.

A semiconductor device includes a substrate; a fin structure disposed over the substrate; a gate structure disposed over the substrate, wherein an extension direction of the fin structure intersects an extension direction of the gate structure; and a first well disposed under the gate structure, corresponding to an emitter region of the semiconductor device, and having a first conductivity type, wherein the first well is adjacent to a well block layer, and the well block layer is disposed under the gate structure in the emitter region; wherein the well block layer has a first doping concentration of a well implant, the first well has a second doping concentration of the well implant, and the first doping concentration is less than the second doping concentration.

An electrostatic discharge protection device includes a substrate, a first doping region of a first conductivity type on the substrate, a second doping region of the first conductivity type on the substrate, an epitaxial layer of a second conductivity type between the first doping region and the second doping region, a first diffusion region of the first conductivity type on the first doping region, a second diffusion region of the second conductivity type on the epitaxial layer, a third diffusion region of the first conductivity type on the second doping region, and a fourth diffusion region of the second conductivity type on the first doping region and spaced apart from the first diffusion region. The first diffusion region and the fourth diffusion region are electrically coupled.

A bipolar junction transistor includes an emitter region, a base region, a collector region and a plurality of fin structures. The emitter region is disposed on a substrate. The base region surrounds the emitter region. The collector region surrounds the base region. The plurality of fin structures are disposed in the base region and surround the emitter region, and the plurality of fin structures fixedly extend along a direction and parallel to each other.

A lateral bipolar transistor includes an emitter region doped with a first conductivity type, having a first width and a first average doping concentration; a collector region doped with the first conductivity type, having a second width greater than the first width of the emitter region and a second average doping concentration lower than the first average doping concentration; and a base region positioned between the emitter and collector regions. The emitter, collector and base regions are arranged in a silicon layer on an insulator layer on a substrate. A substrate region that is deprived of the silicon and insulator layers is positioned on a side of the collector region. A bias circuit is coupled, and configured to deliver, to the substrate region a bias voltage. This bias voltage is controlled to modulate an electrostatic doping of the collector region.