Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Other

Kazunari Hatade

Hajime Akiyama

Kazuhiro Shimizu

Yoshiaki Hisamoto

Hiroshi Yamaguchi

Youichi Ishimura

Kazutoyo Takano

A semiconductor device has a semiconductor substrate having an upper main surface and a lower main surface. The semiconductor substrate includes a drain layer, a main base region, an underpad base region and a source region. The semiconductor device includes a first main electrode connected to the main base regions and the source region and not connected to the underpad base region, a gate electrode opposed to a channel region in the main base region interposed between the drain layer and the source region with a gate insulating film provided therebetween, a conductive gate pad opposed to an exposed surface of the underpad base region in the upper main surface with an insulating layer interposed therebetween and the conductive gate pad is connected to the gate electrode, and a second main electrode connected to the lower main surface.

Semiconductor device with peripheral base region connected to main electrode

A horizontal semiconductor device includes a semiconductor substrate of a first conductivity type and a semiconductor region of a second conductivity type on the semiconductor substrate. The device includes a collector layer of the first conductivity type within the semiconductor region, an endless base layer of the first conductivity type within the semiconductor region, and an endless first emitter layer of the second conductivity type in the endless base layer. The endless base layer is off the collector layer but surrounds the collector layer. A movement of carriers between the endless first emitter layer and the collector layer is controlled in a channel region formed in the endless base layer. An insulation film is disposed between the semiconductor substrate and the semiconductor region. A region of the first conductivity type is disposed in the semiconductor region to contact with a surface of the endless base layer nearest the semiconductor substrate.

Semiconductor device

A semiconductor device has a semiconductor substrate having an upper main surface and a lower main surface. The semiconductor substrate includes a drain layer, a main base region, an underpad base region and a source region. The semiconductor device includes a first main electrode connected to the main base region and the source region and not connected to the underpad base region, a gate electrode opposed to a channel region in the main base region interposed between the drain layer and the source region with a gate insulating film provided therebetween, a conductive gate pad opposed to an exposed surface of the underpad base region in the upper main surface with an insulating layer interposed therebetween and the conductive gate pad is connected to the gate electrode, and a second main electrode connected to the lower main surface.

An n-emitter layer arranged under an emitter electrode is formed of convex portions arranged at predetermined intervals and a main body coupled to the convex portions. A convex portion region is in contact with the emitter electrode, and a p-layer doped more heavily than a p-base layer is arranged at least below the emitter layer. In a power transistor of a lateral structure, a latch-up immunity of a parasitic thyristor can be improved, and a turn-off time can be reduced.

A horizontal semiconductor device having multiple unit semiconductor elements, each of said unit semiconductor element formed by an IGBT including: a semiconductor substrate of a first conductivity type; a semiconductor region of a second conductivity type formed on the semiconductor substrate; a collector layer of the first conductivity type formed within the semiconductor region; a ring-shaped base layer of the first conductivity type formed within the semiconductor region such that the base layer is off said collector layer but surrounds said collector layer; and a ring-shaped first emitter layer of the second conductivity type formed in said base layer, wherein movement of carriers between the first emitter layer and the collector layer is controlled in a channel region formed in the base layer, and the unit semiconductor elements are disposed adjacent to each other.

A semiconductor device is provided which is capable of avoiding malfunction and latchup breakdown resulting from negative variation of high-voltage-side floating offset voltage (VS). In the upper surface of an n-type impurity region, a p-type impurity region is formed between an NMOS and a PMOS and in contact with a p-type well. An electrode resides on the p-type impurity region and the electrode is connected to a high-voltage-side floating offset voltage (VS). The p-type impurity region has a higher impurity concentration than the p-type well and is shallower than the p-type well. Between the p-type impurity region and the PMOS, an n-type impurity region is formed in the upper surface of the n-type impurity region. An electrode resides on the n-type impurity region and the electrode is connected to a high-voltage-side floating supply absolute voltage (VB).

Semiconductor device capable of avoiding latchup breakdown resulting from negative variation of floating offset voltage

Semiconductor device having spaced unit regions and heavily doped semiconductor layer

A semiconductor device including a horizontal unit semiconductor element, the horizontal unit semiconductor element including: a) a semiconductor substrate of a first conductivity type; b) a semiconductor region of a second conductivity type formed on the semiconductor substrate; c) a collector layer of the first conductivity type formed within the semiconductor region; d) a base layer of the first conductivity type having an endless shape and formed within the semiconductor region such that the base layer is off the collector layer but surrounds the collector layer; and e) a first emitter layer of the second conductivity type formed in the base layer, the horizontal unit semiconductor element controlling, within a channel region formed in the base layer, movement of carriers between the first emitter layer and the collector layer, wherein the first emitter layer is formed by plural unit emitter layers which are formed along the base layer.

A semiconductor device is provided which is capable of avoiding malfunction and latchup breakdown resulting from negative variation of high-voltage-side floating offset voltage (VS). In the upper surface of an n-type impurity region (), a p-type impurity region () is formed between an NMOS () and a PMOS () and in contact with a p-type well (). An electrode () resides on the p-type impurity region () and the electrode () is connected to a high-voltage-side floating offset voltage (VS). The p-type impurity region () has a higher impurity concentration than the p-type well () and is shallower than the p-type well (). Between the p-type impurity region () and the PMOS (), an n-type impurity region () is formed in the upper surface of the n-type impurity region (). An electrode () resides on the n-type impurity region () and the electrode () is connected to a high-voltage-side floating supply absolute voltage (VB).

A semiconductor device has an enhanced di/dt tolerance and a dv/dt tolerance without increasing an ON resistance. An underpad base region is provided on a region in an upper main surface of a semiconductor substrate which is provided under a gate pad, and the underpad base region is not connected to a source electrode and is not coupled to a main base region connected to the source electrode. The underpad base region is brought into a floating state.

Semiconductor device having enhanced di/dt tolerance and dV/dt tolerance

A p well serving as a channel region of a MOSFET is formed on one side of an nlayer and an ndrain region is formed on the other side. Above the nlayer, a plurality of first floating field plates are formed with a first insulating film interposed therebetween. A plurality of second floating field plates are formed thereon with a second insulating film interposed therebetween. Assuming that the thickness of the first insulating film is 'a' and the distance between the first floating field plates and the second floating field plates in a direction of thickness of the second insulating film is 'b', a relation a&#x3e;b is held.

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Tokyo, Japan

Kazunari Hatade