Methods and systems for double-sided semiconductor device fabrication. Devices having multiple leads on each surface can be fabricated using a high-temperature-resistant handle wafer and a medium-temperature-resistant handle wafer. Dopants can be introduced on both sides shortly before a single long high-temperature diffusion step diffuses all dopants to approximately equal depths on both sides. All high-temperature processing occurs with no handle wafer or with a high-temperature handle wafer attached. Once a medium-temperature handle wafer is attached, no high-temperature processing steps occur. High temperatures can be considered to be those which can result in damage to the device in the presence of aluminum-based metallizations.

The present disclosure provides embodiments of bipolar junction transistor (BJT) structures. A BJT according to the present disclosure includes a first epitaxial feature disposed over a well region, a second epitaxial feature disposed over the well region, a vertical stack of channel members each extending lengthwise between the first epitaxial feature and the second epitaxial feature, a gate structure wrapping around each of the vertical stack of channel members, a first electrode coupled to the well region, an emitter electrode disposed over and coupled to the first epitaxial feature, and a second electrode disposed over and coupled to the second epitaxial feature.

Provided is a semiconductor device comprising a semiconductor substrate, the semiconductor substrate comprising an active portion, a second conductivity type circumferential well region surrounding the active portion in a top view, and a trench portion provided in the active portion on an upper surface of the semiconductor substrate, wherein the active portion includes a center portion including a first conductivity type emitter region, and a circumferential portion surrounding the center portion, wherein the center portion includes a second conductivity type active side bottom region provided across bottoms of at least two of the trench portion, the circumferential portion includes a second conductivity type circumferential side bottom region electrically connected to the circumferential well region, facing the active side bottom region, and provided at the bottom of the trench portion, and the active side bottom region and the circumferential side bottom region are provided apart from each other.

A Darlington pair sensor is disclosed. The Darlington pair sensor has an amplifying/horizontal bipolar junction transistor (BJT) and a sensing/vertical BJT and can be used as a biosensor.

The amplifying bipolar junction transistor (BJT) is horizontally disposed on a substrate. The amplifying BJT has a horizontal emitter, a horizontal base, a horizontal collector, and a common extrinsic base/collector. The common extrinsic base/collector is an extrinsic base for the amplifying BJT.

The sensing BJT has a vertical orientation with respect to the amplifying BJT. The sensing BJT has a vertical emitter, a vertical base, an extrinsic vertical base, and the common extrinsic base/collector (in common with the amplifying BJT). The common extrinsic base/collector acts as the sensing BJT collector. The extrinsic vertical base is separated into a left extrinsic vertical base and a right extrinsic vertical base giving the sensing BJT has two separated (dual) bases, a sensing base and a control base.

The Darlington pair sensor has high in-situ signal amplification with low noise and uses substrate space effectively.

Operating a bi-directional double-base bipolar junction transistor (B-TRAN). One example is a method comprising: conducting a first load current from an upper terminal of the power module to an upper-main lead of the transistor, through the transistor, and from a lower-main lead of the transistor to a lower terminal of the power module; and then responsive assertion of a first interrupt signal, interrupting the first load current from the lower-main lead to the lower terminal by opening a lower-main FET and commutating a first shutoff current through a lower-control lead the transistor to the lower terminal; and blocking current from the upper terminal to the lower terminal by the transistor.

The present disclosure relates to semiconductor structures and, more particularly, to annular bipolar transistors and methods of manufacture. The structure includes: a substate material; a collector region parallel to and above the substrate material; an intrinsic base region surrounding the collector region; an emitter region above the intrinsic base region; and an extrinsic base region contacting the intrinsic base region

Structures for a bipolar junction transistor and methods of fabricating a structure for a bipolar junction transistor. The structure includes an emitter and a collector comprised of a first two-dimensional material having a first conductivity type, and an intrinsic base comprised of a second two-dimensional material having a second conductivity type different than the first conductivity type. The intrinsic base is laterally positioned between the emitter and the collector.

A heterojunction bipolar transistor includes a first emitter electrode, a second emitter electrode, and a third emitter electrode that are formed on an emitter cap layer. The first emitter electrode has an area greater than or equal to an area of the emitter cap layer in a plan view, and is made of a tungsten alloy. The second emitter electrode is formed on the first emitter electrode, is made of a metal that contains W and is different from a metal of the first emitter electrode, and has an area greater than an area of the first emitter electrode in a plan view.

A bipolar transistor including a first collector layer, a second collector layer, a base layer, and an emitter layer is disposed on a substrate. Etching characteristics of the second collector layer are different from etching characteristics of the first collector layer and the base layer. In plan view, an edge of an interface between the first collector layer and the second collector layer is disposed inside an edge of a lower surface of the base layer, and an edge of an upper surface of the second collector layer coincides with the edge of the lower surface of the base layer or is disposed inside the edge of the lower surface of the base layer.

Aspects of the disclosure provide a bipolar transistor structure with an elevated extrinsic base, and related methods to form the same. A bipolar transistor according to the disclosure may include a collector on a substrate, and a base film on the collector. The base film includes a crystalline region on the collector and a non-crystalline region adjacent the crystalline region. An emitter is on a first portion of the crystalline region of the base film. An elevated extrinsic base is on a second portion of the crystalline region of the base film, and adjacent the emitter.