The invention relates to a field-effect transistor (1;20) with insulated gate electrode (9;30) which comprises in a semiconductor body (5) a drain diffusion zone (2) connected to a drain electrode (6;32) and a source diffusion zone (3) which is disposed spaced from the drain diffusion zone (2) for forming a channel zone (4) and which is connected to a source electrode (7). The gate electrode (9;32) of said field-effect transistor is disposed on a gate insulating layer (8) over the channel zone (...

A MOSFET transistor, in which source and drain regions are formed at a certain distance away from each other in a surface area of a semiconductor substrate having a first conductivity type, and a gate electrode is formed on the surface of the substrate through a gate insulating film formed thereon between the source and drain regions, and in which a channel region located in the surface area of the substrate between the source and drain regions is composed of different concentration regions, and...

An improved cell structure and method for making the same for semicustom chips which can be connected at the metalization step to form either an NPN or a PNP transistor and which has approximately the same cell size as a single PNP or NPN transistor. A central P-doped region forms the emitter of the PNP transistor. This is partially surrounded by another P-doped region which forms the collector of the PNP transistor. An N-doped region is diffused into one of the P-doped regions to form the emitt...

A bipolar transistor of a multi-emitter construction comprises a base diffusion layer formed in a substrate, a number of emitter diffusion layers formed in the base diffusion layer and arranged in a two-dimensional pattern, a base electrode film formed on the base diffusion layer, the base electrode film having a branch connection portion of a mesh-like shape surrounding each group consisting of at least one of the emitter diffusion layers, the base electrode film also having a main connection p...

A bipolar transistor in which a buried collector region, a base region and an emitter region are formed in a device forming region surrounded by an isolation region and in which a base contact electrode and a collector contact electrode are arranged in symmetry with each other, and a process for preparing the transistor. The collector contact electrode is formed through an opening formed in a portion of the isolation region for connection with the buried collector region. In this manner, the col...

A bipolar transistor excellent in the high speed performance comprises a buried region of a first conductivity type formed in a semiconductor substrate, said buried region having a high impurity concentration, a collector region of the first conductivity type formed on the buried region, a base region of a second conductivity type formed on the collector region, an emitter region of the first conductivity type formed on the base region, and an outer base region of the second conductivity type fo...

A bipolar transistor includes a p-type external base region formed on the major surface of an n-type semiconductor substrate, a plurality of p-type internal base regions formed to be surrounded by the external base region, and emitter regions of a first conductivity type respectively formed in the internal base regions. An oxide film and a nitride film, stacked on each other, extend outward from an outer peripheral portion of the external base region on the major surface of the semiconductor sub...

A transistor circuit is disclosed in which a region with opposite conductivity type to that of an emitter region or a MOS type structure is disposed adjacent to the emitter region within the diffusion length from an emitter-base junction. A gain control circuit is constructed by varying the emitter-grounded current amplification factor h.sub.FE of a transistor.

A low-noise, small-signal transistor amplifier particularly suited for use as a preamplifier in an acoustic or audio apparatus employs a field effect transistor having triode-type characteristics in a common source type amplification circuit, with the gate of the field effect transistor being connected directly to an input terminal which receives the audio signals to be amplified, the drain of the field effect transistor being connected to an output terminal, preferably through a capacitor for D...

A circuit and method for indicating the rise time in switching a transistor on, and the fall time in switching the transistor off. A voltage is produced indicative of the transistor collector current and this voltage is compared with first and second reference voltage levels indicative of 10% and 90% of the maximum collector current. To measure rise time, a pulse counter is started when the 10% level is reached and stopped when the 90% level is reached. To measure fall time, a second pulse count...