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.

The current disclosure describes techniques for forming gate-all-around (“GAA”) devices from stacks of separately formed nanowire semiconductor strips. The separately formed nanowire semiconductor strips are tailored for the respective GAA devices. A trench is formed in a first stack of epitaxy layers to define a space for forming a second stack of epitaxy layers. The trench bottom is modified to have determined or known parameters in the shapes or crystalline facet orientations. The known parameters of the trench bottom are used to select suitable processes to fill the trench bottom with a relatively flat base surface.

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.

The current disclosure describes techniques for forming gate-all-around (“GAA”) devices from stacks of separately formed nanowire semiconductor strips. The separately formed nanowire semiconductor strips are tailored for the respective GAA devices. A trench is formed in a first stack of epitaxy layers to define a space for forming a second stack of epitaxy layers. The trench bottom is modified to have determined or known parameters in the shapes or crystalline facet orientations. The known parameters of the trench bottom are used to select suitable processes to fill the trench bottom with a relatively flat base surface.

A method includes providing a semiconductor structure having an active region and an isolation structure adjacent to the active region, the active region having source and drain regions sandwiching a channel region for a transistor, the semiconductor structure further having a gate structure over the channel region. The method further includes etching a trench in one of the source and drain regions, wherein the trench exposes a portion of a sidewall of the isolation structure, epitaxially growing a first semiconductor layer in the trench, epitaxially growing a second semiconductor layer over the first semiconductor layer, changing a crystalline facet orientation of a portion of a top surface of the second semiconductor layer by an etching process, and epitaxially growing a third semiconductor layer over the second semiconductor layer after the changing of the crystalline facet orientation.

A device including a transistor is fabricated by forming a first part of a first region of the transistor through the implantation of dopants through a first opening. The second region of the transistor is then formed in the first opening by epitaxy.

A transistor is produced by forming a first part of a first region of the transistor in a semiconductor substrate by implanting dopants through an opening in an isolating trench formed at an upper surface of the semiconductor substrate. A second region of the transistor in the opening by epitaxy.

The present disclosure relates to semiconductor structures and, more particularly, to virtual bulk in semiconductor on insulator technology and methods of manufacture. The structure includes a heterojunction bipolar transistor formed on a semiconductor on insulator (SOI) wafer with a doped sub-collector material in a buried insulator region under a semiconductor substrate of the SOI wafer.

A method includes providing a semiconductor structure having an active region and an isolation structure adjacent to the active region, the active region having source and drain regions sandwiching a channel region for a transistor, the semiconductor structure further having a gate structure over the channel region. The method further includes etching a trench in one of the source and drain regions, wherein the trench exposes a portion of a sidewall of the isolation structure, epitaxially growing a first semiconductor layer in the trench, epitaxially growing a second semiconductor layer over the first semiconductor layer, changing a crystalline facet orientation of a portion of a top surface of the second semiconductor layer by an etching process, and epitaxially growing a third semiconductor layer over the second semiconductor layer after the changing of the crystalline facet orientation.

Disclosed examples provide fabrications methods and integrated circuits with back ballasted NPN bipolar transistors which include an n-type emitter in a P doped region, a p-type base with a first side facing the emitter, and an n-type collector laterally spaced from a second side of the base, where the collector includes a first side facing the second side of the base, an opposite second side, a silicided first collector portion and a silicide blocked second collector portion covered with a non-conductive dielectric that extends laterally between the first collector portion and the second side of the collector to provide back side ballasting for lateral breakdown and low current conduction via a deep N doped region while the vertical NPN turns on at a high voltage.