A semiconductor device comprising: a first electrode; a first semiconductor region of a first conductivity type; a second semiconductor region of a second conductivity type; a third semiconductor region of the second conductivity type provided between the first semiconductor region and the second semiconductor region on the first electrode and having a higher carrier concentration of the second conductivity type than the second semiconductor region; a fourth semiconductor region; a fifth semiconductor region; a sixth semiconductor region; a seventh semiconductor region; a gate electrode; a gate insulating layer; and a second electrode provided on the fifth semiconductor region and the seventh semiconductor region.

According to a first aspect of the present invention, a method of manufacturing semiconductor device includes the step of preparing a silicon substrate. The silicon substrate includes an N-type silicon layer on one surface and at least one of a PN junction, an electrode film, and a protective film on another surface. The method includes the steps of forming a SiTi junction by forming a first electrode film made of titanium on the N-type silicon layer; forming a second electrode film made of AlSi on the first electrode film; forming a third electrode film made of Ni on the second electrode film; and heating the silicon substrate after forming the third electrode film. A titanium silicide layer is not formed between the N-type silicon layer and the first electrode film.

A symmetrically-bidirectional bipolar transistor circuit where the two base contact regions are clamped, through a low-voltage diode and a resistive element, to avoid bringing either emitter junction to forward bias. This avoids bipolar gain in the off state, and thereby avoids reduction of the withstand voltage due to bipolar gain.

A semiconductor device of the present invention includes a semiconductor layer including a main IGBT cell and a sense IGBT cell connected in parallel to each other, a first resistance portion having a first resistance value formed using a gate wiring portion of the sense IGBT cell and a second resistance portion having a second resistance value higher than the first resistance value, a gate wiring electrically connected through mutually different channels to the first resistance portion and the second resistance portion, a first diode provided between the gate wiring and the first resistance portion, a second diode provided between the gate wiring and the second resistance portion in a manner oriented reversely to the first diode, an emitter electrode disposed on the semiconductor layer, electrically connected to an emitter of the main IGBT cell, and a sense emitter electrode disposed on the semiconductor layer, electrically connected to an emitter of the sense IGBT cell.

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.

There are disclosed herein various implementations of a latch-up free power transistor. Such a device includes an insulated gate situated adjacent to a conduction channel in the power transistor, an emitter electrode in direct physical contact with the conduction channel, and a collector electrode in electrical contact with the conduction channel. The power transistor also includes an emitter layer in contact with a surface of a semiconductor substrate adjacent the conduction channel.

A method for forming a bipolar semiconductor switch includes providing a semiconductor body which has a main surface, a back surface arranged opposite to the main surface, and a first semiconductor layer, and reducing a charge carrier life-time in the semiconductor body. The charge carrier life-time is reduced by at least one of indiffusing heavy metal into the first semiconductor layer, implanting protons into the first semiconductor layer and implanting helium nuclei into the first semiconductor layer, so that the charge carrier life-time has, in a vertical direction which is substantially orthogonal to the main surface, a minimum in a lower n-type portion of the first semiconductor layer where a concentration of n-type dopants is substantially close to a maximum.

A semiconductor device according to the present invention includes a first conductive-type semiconductor layer, a second conductive-type base region that is arranged in the front surface portion of the semiconductor layer, a plurality of trenches that extend from a front surface of the semiconductor layer beyond a bottom portion of the base region with an active region being defined therebetween, a plurality of first conductive-type emitter regions that are arranged in the active region, each connecting the trenches adjacent to each other, a gate electrode that is embedded in the trench, an embedding insulating film that is embedded in the trench on the gate electrode and that has an upper surface in the same height position as the front surface of the semiconductor layer or in a height position lower than the front surface and an emitter electrode that covers the active region and the embedding insulating film and that is electrically connected to the base region and the emitter region.

A device includes isolation regions extending into a semiconductor substrate, with a substrate strip between opposite portions of the isolation regions having a first width. A source/drain region has a portion overlapping the substrate strip, wherein an upper portion of the source/drain region has a second width greater than the first width. The upper portion of the source/drain region has substantially vertical sidewalls. A source/drain silicide region has inner sidewalls contacting the vertical sidewalls of the source/drain region.

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