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 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 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.

The present disclosure relates to semiconductor structures and, more particularly, to a bipolar transistor and methods of manufacture. The structure includes: a collector region in a semiconductor substrate; a base region adjacent to the collector region; and an emitter extending above the base region and comprising semiconductor material and a hardmask surrounding a lower portion of the semiconductor material.

Vertical bipolar junction transistors (VBJTs), each with one or more resistors connected in a circuit in different circuit configurations, are disclosed. The VBJT has an emitter substructure that includes an emitter layer, a collector, an intrinsic base, one or more doped epitaxy regions, and one or more resistors. The intrinsic base, the doped epitaxy region(s), and the resistor(s) are stacked upon one another in a channel between the emitter layer and the collector. Various circuit configurations and structures are described including a common-collector circuit, a common-emitter circuit, and an emitter-degenerate circuit. Methods of making these configuration/structures are disclosed.

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 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 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.

Aspects of the disclosure provide an integrated circuit (IC) structure with a bipolar transistor stack within a substrate. The bipolar transistor stack may include: a collector, a base on the collector, and an emitter on a first portion of the base. A horizontal width of the emitter is less than a horizontal width of the base, and an upper surface of the emitter is substantially coplanar with an upper surface of the substrate. An extrinsic base structure is on a second portion of the base of the bipolar transistor stack, and horizontally adjacent the emitter. The extrinsic base structure includes an upper surface above the upper surface of the substrate.

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.