Abstract: A trench-gate transistor (1) has an integral first layer of silicon dioxide (31) which extends from the upper surface (10a) of the semiconductor body (10) over top corners of each cell array trench (20), the integral first layer also providing a thin gate dielectric insulating layer (31A) for a thick gate electrode (41) and the integral first layer also providing a first part (31B) of a stack of materials which constitute a thick trench sidewall insulating layer (31B,32,33) for a thin field plate (42), a layer of silicon nitride (32) providing a second part of the stack and a second layer of silicon dioxide (33) providing a third part of the stack. The integrity of the first silicon dioxide layer (31) over the trench (20) top corners helps to avoid gate (41)—source (24) short circuits. In a method of manufacture (FIGS.

Abstract: The invention relates to a semiconductor device with a substrate (11) and a semiconductor body (12) with a heterojunction bipolar, in particular npn, transistor with an emitter region (1), a base region (2) and a collector region (3), which are provided with, respectively, a first, a second and a third connection conductor (4, 5, 6), and wherein the bandgap of the base region (2) is smaller than that of the collector region (3) or of the emitter region (1), for example by the use of a silicon-germanium mixed crystal instead of pure silicon in the base region (2). Such a device is characterized by a very high speed, but its transistor shows a relatively low BVeeo. In a device (10) according to the invention the doping flux of the emitter region (1) is locally reduced by a further semiconductor region (20) of the second conductivity type which is embedded in the emitter region (1).

Abstract: The invention relates to a so-termed punchthrough diode (10) with a stack of, for example, n++, n?, p+, n++ regions (1,2,3,4). In the known diode, these semiconductor regions (1,2,3,4) are positioned in said order on a substrate (11). The diode is provided with connection conductors (5,6). Such a diode does not have a steep I-V characteristic and is therefore less suitable as a TVSD (=Transient Voltage Suppression Device). In particular at voltages below 5 volts, a punchthrough diode could form an attractive alternative as TVSD. In a punchthrough diode (10) according to the invention, a part of the first semiconductor region (1) bordering on the second semiconductor region (2) comprises a number of sub-regions (1A) which are separated from each other by a further semiconductor region (7) of the second, for example p+, conductivity type which is electrically connected to the first connection conductor (5).

Abstract: A vertical insulated gate transistor is manufactured by providing a trench (26) extending through a source layer (8) and a channel layer (6) towards a drain layer (2). A spacer etch is used to form gate portions (20) along the trench side walls, a dielectric material (30) is filled into the trench between the sidewalls gate portions (20), and a gate electrical connection layer (30) is formed at the top of the trench electrically connecting the gate portions (20) across the trench.