The present application teaches, inter alia, methods and circuits for operating a B-TRAN (double-base bidirectional bipolar junction transistor). Exemplary base drive circuits provide high-impedance drive to the base contact region on the side of the device instantaneously operating as the collector. (The B TRAN is controlled by applied voltage rather than applied current.) Current signals operate preferred implementations of drive circuits to provide diode-mode turn-on and pre-turnoff operation, as well as a hard ON state with low voltage drop (the transistor-ON state). In some preferred embodiments, self-synchronizing rectifier circuits provide adjustable low voltage for gate drive circuits. In some preferred embodiments, the base drive voltage used to drive the c-base region (on the collector side) is varied while base current at that terminal is monitored, so no more base current than necessary is applied. This solves the difficult challenge of optimizing base drive in a B-TRAN.

A p-type well is formed in a semiconductor substrate, and an n.sup.+-type semiconductor region and a p.sup.+-type semiconductor region are formed in the p-type well to be spaced apart from each other. The n.sup.+-type semiconductor region is an emitter semiconductor region of a bipolar transistor, and the p-type well and the p.sup.+-type semiconductor region are base semiconductor regions of the bipolar transistor. An electrode is formed on an element isolation region between the n.sup.+-type semiconductor region and the p.sup.+-type semiconductor region, and at least apart of the electrode is buried in a trench which is formed in the element isolation region. The electrode is electrically connected to the n.sup.+-type semiconductor region.

Device structure and fabrication methods for a bipolar junction transistor. A trench isolation region is formed that bounds an active device region along a sidewall. A dielectric region is formed that extends laterally from the sidewall of the active device region into the active device region. The dielectric region is located beneath a top surface of the active device region such that a section of the active device region is located between the top surface and the dielectric region.

Transistor structures and methods of fabricating transistor structures are provided. The methods include: fabricating a transistor structure at least partially within a substrate, the fabricating including: providing a cavity within the substrate; and forming a first portion and a second portion of the transistor structure at least partially within the cavity, the first portion being disposed at least partially between the substrate and the second portion, where the first portion inhibits diffusion of material from the second portion into the substrate. In one embodiment, the transistor structure is a field-effect transistor structure, and the first portion and the second portion include one of a source region or a drain region of the field-effect transistor structure. In another embodiment, the transistor structure is a bipolar junction transistor structure.

A semiconductor device includes a first mono-crystallized layer including first transistors, and a first metal layer forming at least a portion of connections between the first transistors; and a second layer including second transistors, the second transistors including mono-crystalline material, the second layer overlying the first metal layer, wherein the first metal layer includes aluminum or copper, and wherein the second layer is less than one micron in thickness and includes logic cells.

Complementary high-voltage bipolar transistors in silicon-on-insulator (SOl) integrated circuits is disclosed. In one disclosed embodiment, a collector region is formed in an epitaxial silicon layer disposed over a buried insulator layer. A base region and an emitter are disposed over the collector region. An n-type region is formed under the buried insulator layer (BOX) by implanting donor impurity through the active region of substrate and BOX into a p-substrate. Later in the process flow this n-type region is connected from the top by doped poly-silicon plug and is biased at Vcc. In this case it will deplete lateral portion of PNP collector region and hence, will increase its BV.

A semiconductor memory, including: a first memory cell including a first transistor; a second memory cell including a second transistor; and a memory peripherals transistor, the memory peripherals transistor is overlaying the second transistor or is underneath the first transistor, where the second memory cell overlays the first memory cell at a distance of less than 200 nm, and where the memory peripherals transistor is part of a peripherals circuit controlling the memory.

A method comprises arranging a stack, on a semiconductor substrate, comprising a sacrificial layer and an insulating layer. The insulator layer is at least partially arranged between the semiconductor substrate and the sacrificial layer. A recess is formed within the stack. The recess extends through the stack to the semiconductor substrate so that the recess at least partially overlaps with a surface of the collector region of the semiconductor substrate. The collector region extends from a main surface of the semiconductor substrate into the substrate material. The method further comprises generating a base structure at the collector region and in the recess. The base structure contacts and covers the collector region within the recess of the sacrificial layer. The method further comprises generating an emitter structure at the base structure. The emitter structure contacts and at least partially covers the base structure within the recess of the sacrificial layer.

A bipolar transistor and a method for fabricating a bipolar transistor are disclosed. In one embodiment the bipolar transistor includes a semiconductor body including a collector region and a base region arranged on top of the collector region, the collector region being doped with dopants of a second doping type and the base region being at least partly doped with dopants of a first doping type and an insulating spacers arranged on top of the base region. The semiconductor body further includes a semiconductor layer including an emitter region arranged on the base region and laterally enclosed by the spacers, the emitter region being doped with dopants of the second doping type forming a pn-junction with the base region, wherein the emitter region is fully located above a horizontal plane through a bottom side of the spacers

A semiconductor device includes a P-type semiconductor substrate, a plurality of N-type buried diffusion layers that are arranged in the semiconductor substrate, an N-type first semiconductor layer that is arranged in a first region on a first buried diffusion layer, an N-type second semiconductor layer that is arranged in a second region on a second buried diffusion layer, an N-type first impurity diffusion region that surrounds the first region in plan view, a P-type second impurity diffusion region that is arranged in the second semiconductor layer, an N-type third impurity diffusion region that is arranged in the second semiconductor layer, an N-type fourth impurity diffusion region that is arranged in the first semiconductor layer. The second region is a region in which an N-type impurity diffusion region that has a higher impurity concentration than the second semiconductor layer cannot be arranged.