Structures for a bipolar junction transistor and methods of fabricating a structure for a bipolar junction transistor. The structure includes a first base layer, a second base layer, a first terminal positioned between the first base layer and the second base layer, a second terminal, and a third terminal. The first base layer, the second base layer, and the first terminal are positioned between the second terminal and the third terminal. For example, the first terminal may be positioned in a vertical direction between the first and second base layers.

Disclosed is a semiconductor structure including a device, such as a lateral heterojunction bipolar transistor (HBT), made up of a combination of at least three different semiconductor materials with different bandgap sizes for improved performance. In the device, a base layer of the base region can be positioned laterally between a collector layer of a collector region and an emitter layer of an emitter region and can be physically separated therefrom by buffer layers. The base layer can be made of a narrow bandgap semiconductor material, the collector layer and, optionally, the emitter layer can be made of a wide bandgap semiconductor material, and the buffer layers can be made of a semiconductor material with a bandgap between that of the narrow bandgap semiconductor material and the wide bandgap semiconductor material. Also disclosed herein is a method of forming the structure.

Disclosed is a semiconductor structure including a device, such as a lateral heterojunction bipolar transistor (HBT), made up of a combination of at least three different semiconductor materials with different bandgap sizes for improved performance. In the device, a base layer of the base region can be positioned laterally between a collector layer of a collector region and an emitter layer of an emitter region and can be physically separated therefrom by buffer layers. The base layer can be made of a narrow bandgap semiconductor material, the collector layer and, optionally, the emitter layer can be made of a wide bandgap semiconductor material, and the buffer layers can be made of a semiconductor material with a bandgap between that of the narrow bandgap semiconductor material and the wide bandgap semiconductor material. Also disclosed herein is a method of forming the structure.

Disclosed is a semiconductor structure including at least one bipolar junction transistor (BJT), which is uniquely configured so that fabrication of the BJT can be readily integrated with fabrication of complementary metal oxide semiconductor (CMOS) devices on an advanced silicon-on-insulator (SOI) wafer. The BJT has an emitter, a base, and a collector laid out horizontally across an insulator layer and physically separated. Extension regions extend laterally between the emitter and the base and between the base and the collector and are doped to provide junctions between the emitter and the base and between the base and the collector. Gate structures are on the extension regions. The emitter, base, and collector are contacted. Optionally, the gate structures and a substrate below the insulator layer are contacted and can be biased to optimize BJT performance. Optionally, the structure further includes one or more CMOS devices. Also disclosed is a method of forming the structure.

A semiconductor device having a GeSiSn base region combined with an emitter region and a collector region can be used to fabricate a bipolar transistor or a heterojunction bipolar transistor. The GeSiSn base region can be compositionally graded or latticed matched or strained to GaAs. The GeSiSn base region can be wafer bonded to a GaN or SiC collector region.

A semiconductor device having a GeSiSn base region combined with an emitter region and a collector region can be used to fabricate a bipolar transistor or a heterojunction bipolar transistor. The GeSiSn base region can be compositionally graded or latticed matched or strained to GaAs. The GeSiSn base region can be wafer bonded to a GaN or SiC collector region.

Multiple strain states in epitaxial transistor channel material may be achieved through the incorporation of stress-relief defects within a seed material. Selective application of strain may improve channel mobility of one carrier type without hindering channel mobility of the other carrier type. A transistor structure may have a heteroepitaxial fin including a first layer of crystalline material directly on a second layer of crystalline material. Within the second layer, a number of defected regions of a threshold minimum dimension are present, which induces the first layer of crystalline material to relax into a lower-strain state. The defected regions may be introduced selectively, for example a through a masked impurity implantation, so that the defected regions may be absent in some transistor structures where a higher-strain state in the first layer of crystalline material is desired.

A power amplifier apparatus includes a semiconductor substrate, a plurality of first transistors on the semiconductor substrate, a plurality of second transistors, at least one collector terminal electrically connected to collectors of the plurality of first transistors, a first inductor having a first end electrically connected to the collector terminal and a second end electrically connected to a power supply potential, at least one emitter terminal electrically connected to emitters of the plurality of second transistors and adjacent to the collector terminal in a second direction, a second inductor having a first end electrically connected to the emitter terminal and a second end electrically connected to a reference potential, and at least one capacitor having a first end electrically connected to the collectors of the plurality of first transistors and a second end electrically connected to the emitters of the plurality of second transistors.

A power amplifier apparatus includes a semiconductor substrate, a plurality of first transistors on the semiconductor substrate, a plurality of second transistors, at least one collector terminal electrically connected to collectors of the plurality of first transistors, a first inductor having a first end electrically connected to the collector terminal and a second end electrically connected to a power supply potential, at least one emitter terminal electrically connected to emitters of the plurality of second transistors and adjacent to the collector terminal in a second direction, a second inductor having a first end electrically connected to the emitter terminal and a second end electrically connected to a reference potential, and at least one capacitor having a first end electrically connected to the collectors of the plurality of first transistors and a second end electrically connected to the emitters of the plurality of second transistors.

In an aspect, a heterojunction bipolar transistor (HBT) includes a sub-collector disposed on a collector. The collector has a collector contact disposed on the sub-collector and located on a first side of the heterojunction bipolar transistor. The HBT includes an emitter disposed on an emitter cap. The emitter has an emitter contact disposed on the emitter cap and located on a second side of the heterojunction bipolar transistor. The HBT includes a base having a base contact located on the second side of the heterojunction bipolar transistor.