In a silicon carbide semiconductor device, a trench penetrates a source region and a first gate region and reaches a drift layer. On an inner wall of the trench, a channel layer of a first conductivity-type is formed by epitaxial growth. On the channel layer, a second gate region of a second conductivity-type is formed. A first depressed portion is formed at an end portion of the trench to a position deeper than a thickness of the source region so as to remove the source region at the end portion of the trench. A corner portion of the first depressed portion is covered by a second conductivity-type layer.

A transistor device includes: a first source region and a first drain region spaced apart from each other in a first direction of a semiconductor body; at least two gate regions arranged between the first source region and the first drain region and spaced apart from each other in a second direction of the semiconductor body; at least one drift region adjoining the first source region and electrically coupled to the first drain region; at least one compensation region adjoining the at least one drift region and the at least two gate regions; a MOSFET including a drain node connected to the first source region, a source node connected to the at least two gate region, and a gate node. Active regions of the MOSFET are integrated in the semiconductor body in a device region that is spaced apart from the at least two gate regions.

A semiconductor device includes: an FET structure that is formed next to a looped trench on a semiconductor substrate and that has an n.sup.+ emitter region and an n.sup. drain region facing each other in the depth direction of the looped trench across a p-type base region; a p-type floating region formed on the side of the looped trench opposite to the FET structure; and an emitter connecting part that is electrically connected to the n.sup.+ emitter region and a trench gate provided in the same trench, the emitter connecting part and the trench gate being insulated from each other by the looped trench. The trench gate faces the FET structure, and the emitter connecting part faces the p-type floating region, across an insulating film.

A field oxide film lies extending from the underpart of a gate electrode to a drain region. A plurality of projection parts projects from the side face of the gate electrode from a source region side toward a drain region side. The projection parts are arranged side by side along a second direction (direction orthogonal to a first direction along which the source region and the drain region are laid) in plan view. A plurality of openings is formed in the field oxide film. Each of the openings is located between projection parts adjacent to each other when seen from the first direction. The edge of the opening on the drain region side is located closer to the source region than the drain region. The edge of the opening on the source region side is located closer to the drain region than the side face of the gate electrode.

In one embodiment, a power MOSFET cell includes an N+ silicon substrate having a drain electrode. An N-type drift layer is grown over the substrate. An N-type layer, having a higher dopant concentration than the drift region, is then formed along with a trench having sidewalls. A P-well is formed in the N-type layer, and an N+ source region is formed in the P-well. A gate is formed over the P-well's lateral channel and has a vertical extension into the trench. A positive gate voltage inverts the lateral channel and increases the vertical conduction along the sidewalls to reduce on-resistance. A vertical shield field plate is also located next to the sidewalls and may be connected to the gate. The field plate laterally depletes the N-type layer when the device is off to increase the breakdown voltage. A buried layer and sinker enable the use of a topside drain electrode.

A semiconductor device, including: a semiconductor substrate having a first well region; an insulating layer formed on a first portion of the semiconductor substrate, and contacted with the first well region; a semiconductor layer formed on the insulating layer; an element isolation region reaching to an inside of the first well region, in a cross-sectional view; a first gate electrode layer formed on a first portion of the semiconductor layer via a first gate insulating film; a second gate electrode layer formed on both a second portion of the semiconductor layer via a second gate insulating film and a first portion of the element isolation region; an interlayer insulating film covering the first gate electrode layer, the second gate electrode layer and a second portion of the element isolation region; a first plug conductor layer formed in the interlayer insulating film.

The semiconductor device of the present invention includes a first conductivity type semiconductor layer made of a wide bandgap semiconductor and a Schottky electrode formed to come into contact with a surface of the semiconductor layer, and has a threshold voltage V.sub.th of 0.3 V to 0.7 V and a leakage current J.sub.r of 110.sup.9 A/cm.sup.2 to 110.sup.4 A/cm.sup.2 in a rated voltage V.sub.R.

A semiconductor device with a current terminal region located in a device active area of a substrate of the device. A guard region is located in a termination area of the device. A plurality of floating field plates are located in the termination area and are ohmically coupled to the guard region. The floating field plates and guard region act in some embodiments to smooth the electrical field distribution along the termination area.

Apparatus and associated methods relate to an edge-termination structure surrounding a high-voltage MOSFET for reducing a peak lateral electric field. The edge-termination structure includes a sequence of annular trenches and semiconductor pillars circumscribing the high-voltage MOSFET. Each of the annular trenches is laterally separated from the other annular trenches by one of the semiconductor pillars. Each of the annular trenches has dielectric sidewalls and a dielectric bottom electrically isolating a conductive core within each of the annular trenches from a drain-biased region of the semiconductor pillar outside of and adjacent to the annular trench. The conductive core of the innermost trench is biased, while the conductive cores of one or more outer trenches are floating. In some embodiments, a surface of an inner semiconductor pillar is biased as well. The peak lateral electric field can advantageously be reduced by physical arrangement of trenches and electrical biasing sequence.

Vertical sense devices in vertical trench MOSFET. In accordance with an embodiment of the present invention, a semiconductor device includes a main vertical trench metal oxide semiconductor field effect transistor (main-MOSFET). The main-MOSFET includes a plurality of parallel main trenches, wherein the main trenches comprise a first electrode coupled to a gate of the main-MOSFET, and a plurality of main mesas between the main trenches, wherein the main mesas comprise a main source and a main body of the main-MOSFET. The semiconductor device also includes a sense-diode. The sense-diode includes a plurality of sense-diode trenches, wherein each of the sense-diode trenches comprises a portion of one of the main trenches, and a plurality of sense-diode mesas between the source-FET trenches, wherein the sense-diode mesas comprise a sense-diode anode that is electrically isolated from the main source of the main-MOSFET.