Various particular embodiments include an integrated circuit (IC) structure including: a stack region; and a silicon substrate underlying and contacting the stack region, the silicon substrate including: a silicon region including a doped subcollector region; a set of isolation regions overlying the silicon region; a base region between the set of isolation regions and below the stack region, the base region including an intrinsic base contacting the stack region, an extrinsic base contacting the intrinsic base and the stack region, and an amorphized extrinsic base contact region contacting the extrinsic base; a collector region between the set of isolation regions; an undercut collector-base region between the set of isolation regions and below the base region; and a collector contact region contacting the collector region under the intrinsic base and the collector-base region via the doped subcollector region.

Device structures and fabrication methods for a device structure. One or more trench isolation regions are formed in a substrate to surround a device region. A base layer is formed on the device region. First and second emitter fingers are formed on the base layer. A portion of the device region extending from the first emitter finger to the second emitter finger is free of dielectric material.

A charge control structure is provided for a bipolar junction transistor to control the charge distribution in the depletion region extending into the bulk collector region when the collector-base junction is reverse-biased. The charge control structure comprises a lateral field plate above the upper surface of the collector and dielectrically isolated from the upper surface of the collector and a vertical field plate which is at a side of the collector and is dielectrically isolated from the side of the collector. The charge in the depletion region extending into the collector is coupled to the base as well as the field-plates in the charge-control structure, instead of only being coupled to the base of the bipolar junction transistor. In this way, a bipolar junction transistor is provided where the dependence of collector current on the collector-base voltage, also known as Early effect, can be reduced.

The present disclosure relates to semiconductor structures and, more particularly, to heterojunction bipolar transistors (HBTs) with a buried trap rich isolation region and methods of manufacture. The structure includes: a first heterojunction bipolar transistor; a second heterojunction bipolar transistor; and a trap rich isolation region embedded within a substrate underneath both the first heterojunction bipolar transistor and the second heterojunction bipolar transistor.

A semiconductor apparatus comprises a first semiconductor region including a first surface and a second surface, in which a semiconductor of a first conductivity type is arranged, a second semiconductor region of the first conductivity type, which is arranged between the first surface and the second surface, a third semiconductor region of a second conductivity type, which is arranged in a region between the second semiconductor region and the second surface and on a side portion of the second semiconductor region, a fourth semiconductor region of the first conductivity type, which is arranged between the first surface and the second surface; and a fifth semiconductor region of the second conductivity type, which is arranged in a region between the fourth semiconductor region and the second surface and on a side portion of the fourth semiconductor region.

A semiconductor apparatus comprises a first semiconductor region including a first surface and a second surface, in which a semiconductor of a first conductivity type is arranged, a second semiconductor region of the first conductivity type, which is arranged between the first surface and the second surface, a third semiconductor region of a second conductivity type, which is arranged in a region between the second semiconductor region and the second surface and on a side portion of the second semiconductor region, a fourth semiconductor region of the first conductivity type, which is arranged between the first surface and the second surface; and a fifth semiconductor region of the second conductivity type, which is arranged in a region between the fourth semiconductor region and the second surface and on a side portion of the fourth semiconductor region.

A bipolar junction transistor is provided with a multilayer collector structure. The layers of the collector are individually grown in separate epitaxial growth stages. For a PNP transistor, each layer, after it is grown, is doped with a p-type dopant in a dedicated implant stage. By providing separate epitaxial growth stages and separate dopant implant stages for each layer of the collector, the dopant concentration profile in the collector region can be better controlled to optimize the speed and breakdown voltage of a bipolar junction transistor.

The present disclosure provides embodiments of semiconductor devices. In one embodiment, the semiconductor device includes a dielectric layer and a fin-shaped structure disposed over the dielectric layer. The fin-shaped structure includes a first p-type doped region, a second p-type doped region, and a third p-type doped region, and a first n-type doped region, a second n-type doped region, and a third n-type doped region interleaving the first p-type doped region, the second p-type doped region, and the third p-type doped region. The first p-type doped region, the third p-type doped region and the third n-type doped region are electrically coupled to a first potential. The second p-type doped region, the first p-type doped region and the second p-type doped region are electrically coupled to a second potential different from the first potential.

Various embodiments of the present disclosure are directed towards a method for forming a bipolar junction transistor (BJT). A dielectric film is deposited over a substrate and comprises a lower dielectric layer, an upper dielectric layer, and an intermediate dielectric layer between the lower and upper dielectric layers. A first semiconductor layer is deposited over the dielectric film and is subsequently patterned to form an opening exposing the dielectric film. A first etch is performed into the upper dielectric layer through the opening to extend the opening to the intermediate dielectric layer. Further, the first etch stops on the intermediate dielectric layer and laterally undercuts the first semiconductor layer. Additional etches are performed to extend the opening to the substrate. A lower base structure and an emitter are formed stacked in and filling the opening, and the first semiconductor layer is patterned to form an upper base structure.

A semiconductor device is described including a substrate and a plurality of layers. The semiconductor device includes a cascode arrangement of a first bipolar transistor and a second bipolar transistor. A first-bipolar-transistor-collector of the first bipolar transistor and a second-bipolar-transistor-emitter of the second bipolar transistor are at least partially located in a common region in the same layer of the semiconductor device.