Provided is a semiconductor element having, while maintaining the same integratability as a conventional MOSFET, excellent switch characteristics compared with the MOSFET, that is, having the S-value less than 60 mV/order at room temperature. Combining the MOSFET and a tunnel bipolar transistor having a tunnel junction configures a semiconductor element that shows an abrupt change in the drain current with respect to a change in the gate voltage (an S-value of less than 60 mV/order) even at a low voltage.

In a method of further enhancing the performance of a narrow active cell IE type trench gate IGBT having the width of active cells narrower than that of inactive cells, it is effective to shrink the cells so that the IE effects are enhanced. However, when the cells are shrunk simply, the switching speed is reduced due to increased gate capacitance. A cell formation area of the IE type trench gate IGBT is basically composed of first linear unit cell areas having linear active cell areas, second linear unit cell areas having linear hole collector areas and linear inactive cell areas disposed therebetween.

A heterojunction bipolar transistor (HBT) amplifier device includes transistor fingers arranged in parallel on a substrate. Each transistor finger includes a base/collector mesa stripe shaving a trapezoidal shaped cross-section with sloping sides, and having a base stacked on a collector; a set of emitter mesa stripes arranged on the base/collector mesa stripe; and emitter metallization formed over the set of emitter mesa stripes and the base/collector mesa. The emitter metallization includes a center portion for providing electrical and thermal connectivity to the emitter mesa stripes and extended portions extending beyond the base and overlapping onto the sloping sides of the base/collector mesa stripe for increasing thermal coupling to the collector. A common conductive pillar is formed over the transistor fingers for providing electrical and thermal conductivity. Also, thermal shunts are disposed on the substrate between adjacent transistor fingers, where the thermal shunts are electrically isolated from the transistor fingers.

A transistor switch device is provided that exhibits relatively good voltage capability and relatively easy drive requirements to turn the device on and off. This can reduce transient drive current flows that may perturb other components.

An improvement is achieved in the performance of a semiconductor device. The semiconductor device includes a first trench gate electrode and second and third trench gate electrodes located on both sides of the first trench gate electrode interposed therebetween. In each of a semiconductor layer located between the first and second trench gate electrodes and the semiconductor layer located between the first and third trench gate electrodes, a plurality of p.sup.+-type semiconductor regions are formed. The p.sup.+-type semiconductor regions are arranged along the extending direction of the first trench gate electrode in plan view to be spaced apart from each other.

A transistor switch device is provided that exhibits relatively good voltage capability and relatively easy drive requirements to turn the device on and off. This can reduce transient drive current flows that may perturb other components.

Methods, systems, circuits, and devices for power-packet-switching power converters using bidirectional bipolar transistors (BTRANs) for switching. Four-terminal three-layer BTRANs provide substantially identical operation in either direction with forward voltages of less than a diode drop. BTRANs are fully symmetric merged double-base bidirectional bipolar opposite-faced devices which operate under conditions of high non-equilibrium carrier concentration, and which can have surprising synergies when used as bidirectional switches for power-packet-switching power converters. BTRANs are driven into a state of high carrier concentration, making the on-state voltage drop very low.

A bipolar transistor includes a substrate and a first well in the substrate, the first well having a first dopant type. The bipolar transistor further includes a split collector region in the first well. The split collector region includes a highly doped central region having a second dopant type opposite the first dopant type; and a lightly doped peripheral region having the second dopant type, the lightly doped peripheral region surrounding the highly doped central region. A dopant concentration of the lightly doped peripheral region is less than a dopant concentration of the highly doped central region.

A method of producing a semiconductor device is presented. The method comprises: providing a semiconductor substrate having a surface; epitaxially growing, along a vertical direction (Z) perpendicular to the surface, a back side emitter layer on top of the surface, wherein the back side emitter layer has dopants of a first conductivity type or dopants of a second conductivity type complementary to the first conductivity type; epitaxially growing, along the vertical direction (Z), a drift layer having dopants of the first conductivity type above the back side emitter layer, wherein a dopant concentration of the back side emitter layer is higher than a dopant concentration of the drift layer; and creating, either within or on top of the drift layer, a body region having dopants of the second conductivity type, a transition between the body region and the drift layer forming a pn-junction (Zpn). Epitaxially growing the drift layer includes creating, within the drift layer, a dopant concentration profile (P) of dopants of the first conductivity type along the vertical direction (Z), the dopant concentration profile (P) in the drift layer exhibiting a variation of a concentration of dopants of the first conductivity type along the vertical direction (Z).

A semiconductor memory cell includes a floating body region configured to be charged to a level indicative of a state of the memory cell selected from at least first and second states. A first region of the memory cell is in electrical contact with the floating body region. A second region of the memory cell is spaced apart from the first region and is also in electrical contact with the floating body region. A gate is positioned between the first and second regions. A back-bias region is configured to generate impact ionization when the memory cell is in one of the first and second states, and the back-bias region is configured so as not to generate impact ionization when the memory cell is in the other of the first and second states.