This disclosure relates to bipolar transistors, such as heterojunction bipolar transistors, having at a doping spike in the collector. The doping spike can be disposed relatively near an interface between the collector and the base. For instance, the doping spike can be disposed within half of the thickness of the collector from the interface between the collector and the base. Such bipolar transistors can be implemented, for example, in power amplifiers.

A method for manufacturing a silicon carbide device includes providing a silicon carbide wafer and manufacturing a mask layer on top of the silicon carbide wafer. Further, the method includes structuring the mask layer at an edge of a silicon carbide device to be manufactured, so that the mask layer includes a bevel at the edge of the silicon carbide device to be manufactured. Additionally, the method includes etching the mask layer and the silicon carbide wafer by a mutual etching process, so that the bevel of the mask layer is reproduced at the edge of the silicon carbide device.

Methods and systems include constructing and operating a semiconductor device with a mid-band dopant layer. In various implementations, carriers that are optically excited in a mid-band dopant region may provide injection currents that may reduce transition times and increase achievable operating frequency in a bipolar junction transistor (BJT). In various implementations, carriers that are optically excited in a mid-band dopant region within a thyristor may improve closure transition time, effective current spreading velocity, and maximum rate of current rise.

Provided is a small-sized device for measuring an oxidation-reduction potential, whereby an oxidation-reduction current and an oxidation-reduction potential can be measured by reducing noise even when a signal from a solution being measured is small. A device for measuring an oxidation-reduction potential is provided with a substrate (10), a working electrode (15) mounted on a surface of the substrate (10), and a bipolar transistor (21) for amplifying the output of the working electrode (15) also provided on the surface of the substrate (10), and the signal amplified by the bipolar transistor (21) is inputted to a processing circuit (18).

A switching circuit switches a first IGBT and a second IGBT. A control circuit is equipped with a first switching element that is configured to be able to control a gate current of the first IGBT, a second switching element that is configured to be able to control a gate current of the second IGBT, and a third switching element that is connected between an electrode of the first IGBT and an electrode of the second IGBT. The control circuit controls a turn on timing and turn off timing.

Techniques for providing a direct injection semiconductor memory device are disclosed. In one particular exemplary embodiment, the techniques may be realized as a direct injection semiconductor memory device including a first region coupled to a source line, a second region coupled to a bit line. The direct injection semiconductor memory device may also include a body region spaced apart from and capacitively coupled to a word line, wherein the body region is electrically floating and disposed between the first region and the second region. The direct injection semiconductor memory device may further include a third region coupled to a carrier injection line configured to inject charges into the body region through the second region.

A two-surface bidirectional power bipolar transistor is constructed with a two-surface cellular layout. Each emitter/collector region (e.g. doped n-type) is a local center of the repeated pattern, and is surrounded by a trench with an insulated field plate, which is tied to the potential of the emitter/collector region. The outer (other) side of this field plate trench is preferably surrounded by a base connection region (e.g. p-type), which provides an ohmic connection to the substrate. The substrate itself serves as the transistor's base.

A vertical semiconductor device (e.g. a vertical power device, an IGBT device, a vertical bipolar transistor, a UMOS device or a GTO thyristor) is formed with an active semiconductor region, within which a plurality of semiconductor structures have been fabricated to form an active device, and below which at least a portion of a substrate material has been removed to isolate the active device, to expose at least one of the semiconductor structures for bottom side electrical connection and to enhance thermal dissipation. At least one of the semiconductor structures is preferably contacted by an electrode at the bottom side of the active semiconductor region.

The current disclosure describes a new vertical tunnel field-effect transistor (TFET). The TFET includes a source layer over a substrate. A first channel layer is formed over the source layer. A drain layer is stacked over the first channel layer with a second channel layer stacked therebetween. The drain layer and the second channel layer overlap a first surface portion of the first channel layer. A gate structure is positioned over the channel layer by a second surface portion of the channel layer and contacts a sidewall of the second channel layer.

A switching circuit includes a wiring into which a parallel circuit of a first IGBT and a second IGBT is inserted, and a gate control circuit. The gate control circuit has a first switching element configured to control a gate potential of the first IGBT according to a potential of a second principal electrode, and a second switching element configured to control a gate potential of the second IGBT according to a potential of a fourth principal electrode. An output terminal of the control device is connected to the first switching element through a first switch and is connected to the second switching element through a second switch. The control device applies a control signal to the output terminal in a state where the first switch and the second switch are turned on when switching both of the first IGBT and the second IGBT.