The present disclosure relates to semiconductor structures and, more particularly, to a lateral bipolar transistor and methods of manufacture. The structure includes: an extrinsic base region within a semiconductor substrate material; a shallow trench isolation structure extending into the semiconductor substrate material and bounding the extrinsic base region; an emitter region adjacent to the shallow trench isolation structure and on a side of the extrinsic base region; and a collector region adjacent to the shallow trench isolation structure and on an opposing side of the extrinsic base region.

Disclosed is a semiconductor structure including a lateral heterojunction bipolar transistor (HBT). The structure includes a substrate (e.g., a silicon substrate), an insulator layer on the substrate, and a semiconductor layer (e.g., a silicon germanium layer) on the insulator layer. The structure includes a lateral HBT with three terminals including a collector, an emitter, and a base, which is positioned laterally between the collector and the emitter and which can include a silicon germanium intrinsic base region for improved performance. Additionally, the collector and/or the emitter includes: a first region, which is epitaxially grown within a trench that extends through the semiconductor layer and the insulator layer to the substrate; and a second region, which is epitaxially grown on the first region. The connection(s) of the collector and/or the emitter to the substrate effectively form thermal exit path(s) and minimize self-heating. Also disclosed is a method for forming the structure.

The present disclosure relates to semiconductor structures and, more particularly, to a lateral bipolar transistor and methods of manufacture. The structure includes: an extrinsic base having at least one sidewall with a gradient concentration of semiconductor material; an emitter on a first side of the extrinsic base; and a collector on a second side of the extrinsic base.

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.

A bipolar junction transistor includes an extrinsic collector region buried in a semiconductor substrate under an intrinsic collector region. Carbon-containing passivating regions are provided to delimit the intrinsic collector region. An insulating layer on the intrinsic collector region includes an opening within which an extrinsic base region is provided. A semiconductor layer overlies the insulating layer, is in contact with the extrinsic base region, and includes an opening with insulated sidewalls. The collector region of the transistor is provided between the insulated sidewalls.

A circuit element is formed on a substrate made of a compound semiconductor. A bonding pad is disposed on the circuit element so as to at least partially overlap the circuit element. The bonding pad includes a first metal film and a second metal film formed on the first metal film. A metal material of the second metal film has a higher Young's modulus than a metal material of the first metal film.

A disclosed structure includes a bipolar junction transistor (BJT) and a method of forming the structure. The structure includes a semiconductor layer on an insulator layer. The BJT includes a base region positioned laterally between emitter and collector regions. The emitter region includes an emitter portion of the semiconductor layer and an emitter semiconductor layer, which is within an emitter cavity in the insulator layer, which extends through an emitter opening in the emitter portion, and which covers the top of the emitter portion. The collector region includes a collector portion of the semiconductor layer and a collector semiconductor layer, which is within a collector cavity in the insulator layer, which extends through a collector opening in the collector portion, and which covers the top of the collector portion. Optionally, the structure also includes air pockets within the emitter and collector cavities.

The present disclosure relates to semiconductor structures and, more particularly, to a bipolar transistor with a collector contact and methods of manufacture. The structure includes: a lateral bipolar transistor which includes an emitter, a base and a collector; an emitter contact to the emitter; a base contact to the base; and a collector contact to the collector and extending to an underlying substrate underneath the collector.

Structures for a bipolar junction transistor and methods of forming a structure for a bipolar junction transistor. The structure comprises a first terminal including a first raised semiconductor layer, a second terminal including a second raised semiconductor layer, and a base layer 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 structure further comprises a modulator including a semiconductor layer in direct contact with the base layer. The base layer has a first conductivity type, and the semiconductor layer has a second conductivity type opposite to the first conductivity type.