A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes first and second epitaxial layers, and first and second semiconductor layers. The second epitaxial layer is disposed on the first epitaxial layer. The first semiconductor layer extends from above the second epitaxial layer to a top surface of the second epitaxial layer. A vertically extending region of the first semiconductor layer has a body portion and an extending portion extending from a bottom end of the body portion to the second epitaxial layer. A width of the body portion is greater than a width of the extending portion. The second semiconductor layer is disposed on the second epitaxial layer, and laterally surrounds the vertically extending region of the first semiconductor layer. A portion of the second semiconductor layer extends between and overlaps with the body portion of the first semiconductor layer and the second epitaxial layer.

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.

The present disclosure relates to semiconductor structures and, more particularly, to heterojunction bipolar transistors and methods of manufacture. The structure includes: a first semiconductor layer including a device region; a second semiconductor layer under the first semiconductor layer; a layer of conductive material between the first semiconductor layer and the second semiconductor layer; at least one contact extending to and contacting the layer of conductive material; and a device in the device region above the layer of conductive material.

The present disclosure relates to semiconductor structures and, more particularly, to a device with a marker layer and methods of manufacture. The device includes: a collector region; an intrinsic base region above the collector region; an emitter region comprising emitter material and a marker layer vertically between the intrinsic base region and the emitter material; and an extrinsic base region in electrical contact with the intrinsic base region.

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.

A microelectronic device is formed by forming at least a portion of a substrate of the microelectronic device by one or more additive processes. The additive processes may be used to form semiconductor material of the substrate. The additive processes may also be used to form dielectric material structures or electrically conductive structures, such as metal structures, of the substrate. The additive processes are used to form structures of the substrate which would be costly or impractical to form using planar processes. In one aspect, the substrate may include multiple doped semiconductor elements, such as wells or buried layers, having different average doping densities, or depths below a component surface of the substrate. In another aspect, the substrate may include dielectric isolation structures with semiconductor material extending at least partway over and under the dielectric isolation structures. Other structures of the substrate are disclosed.

A semiconductor device having tipless epitaxial source/drain regions and a method for its formation are described. In an embodiment, the semiconductor device comprises a gate stack on a substrate. The gate stack is comprised of a gate electrode above a gate dielectric layer and is above a channel region in the substrate. The semiconductor device also comprises a pair of source/drain regions in the substrate on either side of the channel region. The pair of source/drain regions is in direct contact with the gate dielectric layer and the lattice constant of the pair of source/drain regions is different than the lattice constant of the channel region. In one embodiment, the semiconductor device is formed by using a dielectric gate stack placeholder.

Methods of manufacturing heterojunction bipolar transistors are described herein. An exemplary method can include providing an emitter/base stack comprising a substrate, a base over the substrate, and/or an emitter over the base. The exemplary method further can include forming a collector. The exemplary method also can include wafer bonding the base to the collector. Other embodiments are also disclosed herein.

An integrated circuit formed on a silicon substrate includes an NMOS transistor with n-channel raised source and drain (NRSD) layers adjacent to a gate of the NMOS transistor, a PMOS transistor with SiGe stressors in the substrate adjacent to a gate of the PMOS transistor, and an NPN heterojunction bipolar transistor (NHBT) with a p-type SiGe base formed in the substrate and an n-type silicon emitter formed on the SiGe base. The SiGe stressors and the SiGe base are formed by silicon-germanium epitaxy. The NRSD layers and the silicon emitter are formed by silicon epitaxy.

A method of making a bipolar transistor includes forming a stack of a first, second, third and fourth insulating layers on a substrate. An opening is formed in the stack to reach the substrate. An epitaxial process forms the collector of the transistor on the substrate and selectively etches an annular opening in the third layer. The intrinsic part of the base is then formed by epitaxy on the collector, with the intrinsic part being separated from the third layer by the annular opening. The junction between the collector and the intrinsic part of the base is surrounded by the second layer. The emitter is formed on the intrinsic part and the third layer is removed. A selective deposition of a semiconductor layer on the second layer and in direct contact with the intrinsic part forms the extrinsic part of the base.