A semiconductor device includes: a silicon substrate that includes a high-concentration layer containing first conductivity type impurities; a low-concentration layer formed on the high-concentration layer and containing first conductivity type impurities; a first electrode and a second electrode formed on the low-concentration layer; a vertical semiconductor element that allows current to flow between the second electrode and the high-concentration layer; and a first trench unit that realizes electric connection between the first electrode and the high-concentration layer. The first trench unit consists of first polysilicon containing first conductivity type impurities, and a diffusion layer configured to surround the first polysilicon in a plan view and to contain first conductivity type impurities. The first polysilicon is configured to reach the high-concentration layer by penetrating the low-concentration layer. Respective concentrations of the first conductivity type impurities contained in the first polysilicon and in the diffusion layer are kept constant in a direction from the low-concentration layer to the high-concentration layer.

A two-transistor memory cell based upon a thyristor for an SRAM integrated circuit is described together with a process for fabricating it. The memory cell can be implemented in different combinations of MOS and bipolar select transistors, or without select transistors, with thyristors in a semiconductor substrate with shallow trench isolation. Standard CMOS process technology can be used to manufacture the SRAM.

A 3D semiconductor device, the device including: a first level including a first single crystal layer and including first transistors each of which includes a single crystal channel; a first metal layer; a second metal layer overlaying the first metal layer; a second level including second transistors and overlaying the second metal layer, each of first memory cells include at least one second transistor; a third level including third transistors and overlaying the second level; a fourth level including fourth transistors and overlaying the third level, each of second memory cells include at least one fourth transistor, where at least one of the second transistors includes a metal gate, where the first level includes memory control circuits which control writing to the second memory cells, and at least one of the second transistors includes a hafnium oxide gate dielectric.

Methods, devices, and systems for using and forming vertically base-connected bipolar transistors have been shown. The vertically base-connected bipolar transistors in the embodiments of the present disclosure are formed with a CMOS fabrication technique that decreases the transistor size while maintaining the high performance characteristics of a bipolar transistor.

Methods of forming bipolar device structures and bipolar device structures. An opening may be formed in a device layer of a silicon-on-insulator substrate that extends to a buried insulator layer of the silicon-on-insulator substrate. An intrinsic base layer may be grown within the device layer opening by lateral growth on opposite first and second sidewalls of the device layer bordering the opening. A first collector of a first bipolar junction transistor of the device structure may be formed at a first spacing from the first sidewall. A second collector of a second bipolar junction transistor of the device structure may be formed at a second spacing from the second sidewall. An emitter, which is shared by the first bipolar junction transistor and the second bipolar transistor, is formed inside the opening. Portions of the intrinsic base layer may supply respective intrinsic bases for the first and second bipolar junction transistors.

A method for forming a bipolar junction transistor includes forming a collector intrinsic region, an emitter intrinsic region and an intrinsic base region between the collector intrinsic region and the emitter intrinsic region. A collector extrinsic contact region is formed in direct contact with the collector intrinsic region; an emitter extrinsic contact region is formed on the emitter intrinsic region and a base extrinsic contact region is formed in direct contact with the intrinsic base region. Carbon is introduced into at least one of the collector extrinsic contact region, the emitter extrinsic contact region and the base extrinsic contact region to suppress diffusion of dopants into the junction region.

An integrated circuit includes an NMOS transistor, a PMOS transistor and a vertical bipolar transistor. The vertical bipolar transistor has an intrinsic base with a band barrier at least 25 meV high at a surface boundary of the intrinsic base, except at an emitter-base junction with an emitter, and except at a base-collector junction with a collector. The intrinsic base may be laterally surrounded by an extrinsic base with a higher dopant density than the intrinsic base, wherein a higher dopant density provides the band barrier at lateral surfaces of the intrinsic base. A gate may be disposed on a gate dielectric layer over a top surface boundary of the intrinsic base adjacent to the emitter. The gate is configured to accumulate the intrinsic base immediately under the gate dielectric layer, providing the band barrier at the top surface boundary of the intrinsic base.

Some aspects of this disclosure relate to a memory device. The memory device includes a collector region having a first conductivity type and which is coupled to a source line of the memory device. A base region is formed over the collector region and has a second conductivity type. A gate structure is coupled to the base region and acts as a shared word line for first and second neighboring memory cells of the memory device. First and second emitter regions are formed over the base region and have the first conductivity type. The first and second emitter regions are arranged on opposite sides of the gate structure. First and second contacts extend upwardly from the first and second emitter regions, respectively, and couple the first and second emitter regions to first and second data storage elements, respectively, of the first and second neighboring memory cells, respectively.

Device structures for a bipolar junction transistor and methods of fabricating a device structure for a bipolar junction transistor. A first semiconductor layer is formed on a substrate, and a second semiconductor layer is formed on the first semiconductor layer. The first semiconductor layer, the second semiconductor layer, and the substrate are etched to define first and second emitter fingers from the second semiconductor layer and trenches in the substrate that are laterally positioned between the first and second emitter fingers. The first semiconductor layer may function as a base layer in the device structure.

The present invention concerns a monolithically merged trenched-and-implanted Bipolar Junction Transistor (TI-BJT) with antiparallel diode and a method of manufacturing the same. Trenches are made in a collector, base, emitter stack downto the collector. The base electrode is formed on an implanted base contact region at the bottom surface of the trench. The present invention also provides for products produced by the methods of the present invention and for apparatuses used to perform the methods of the present invention.