A semiconductor device is provided. On one main surface side of an n-type semiconductor substrate, a p-type diffusion region to serve as an anode of a diode is formed. A guard ring formed of a p-type diffusion region is formed to surround the anode. On the other main surface side, an n-type ultrahigh-concentration impurity layer and an n-type high-concentration impurity layer to serve as a cathode are formed. In a guard-ring opposed region located in the cathode and opposite to the guard ring, a cathode-side p-type diffusion region is formed. Accordingly, concentration of the electric current on an outer peripheral end portion of the anode is suppressed.

A VDMOS includes a substrate; an epitaxial layer; first and second trenches defined in the epitaxial layer; a shielding gate and a control gate formed in the trenches; a body region formed at the epitaxial layer and between the first and second trenches; a N+ source region formed at the body region; a distinct doping region formed in the epitaxial layer underneath the body region, extending towards bottoms of the trenches; a channel defined between the N+ source region and epitaxial layer adjacent to the trenches; an insulating layer defining a contact hole extending into the body region and the first trench; a P+ body pickup region formed in the body region corresponding to the contact hole; and a metal layer haying a butting contact filled in the contact hole, connecting the N+ source region, P+ body pickup region, and control gate and/or shielding gate in the first trench.

An integrated device includes a semiconductor well formed in an epitaxial layer, and a guard ring formed in the epitaxial layer and surrounding the semiconductor well. The semiconductor well and the guard ring include a type of semiconductor different from that of the epitaxial layer. The integrated device also includes an insulating layer formed atop the guard ring, and multiple gate electrodes formed on a top surface of the insulating layer, overlapping the guard ring and surrounding the semiconductor well. The gate electrodes include a first gate electrode and a second gate electrode separated by a gap. An intersecting line between the top surface of the insulating layer and a side wall of the first gate electrode partially overlaps an area that is defined based on an intersecting line between the top surface of the insulating layer and a side wall of the second gate electrode above the guard ring.

A horizontal MOSFET is arranged in parallel to a horizontal MOSFET and a portion of a return current IL which flows to a linear solenoid flows as a current to the horizontal MOSFET. Therefore, a current which flows to a parasitic transistor is reduced and it is possible to suppress the current which flows to the parasitic transistor provided in the horizontal MOSFET. Since the current which flows to the parasitic transistor is reduced, it is possible to prevent the erroneous operation and breakdown of a semiconductor device forming a synchronous rectification circuit.

A trench type power semiconductor device with improved breakdown voltage and UIS performance and a method for preparation the device are disclosed. The trench type power semiconductor device includes a first contact hole formed in a mesa in the active area and a second contact hole formed in a mesa in an active to termination intermediate area, where the first contact hole is deeper and wider than the second contact hole.

A super-junction semiconductor device includes a junction termination area at a first surface of a semiconductor body and at least partly surrounding an active cell area. An inner part of the junction termination area is arranged between an outer part of the junction termination area and the active cell area. A charge compensation device structure includes first regions of a first conductivity type and second regions of a second conductivity type disposed alternately along a first lateral direction. First surface areas correspond to a projection of the first regions onto the first surface, and second surface areas correspond to a projection of the second regions onto the first surface. The super-junction semiconductor device further includes at least one of a first junction termination extension structure and a second junction termination extension structure.

This invention provides a composite device and a switching power supply. The composite device integrates therein a first enhancement-mode MOS device and a depletion-mode MOS device, and comprises: an epitaxial region of a first doping type; a first well region and a second well region formed in parallel on the front side of the epitaxial region; a first doped region of the first doping type formed within the first well region; a gate of the first enhancement-mode MOS device; a second doped region of the first doping type formed within the second well region; a channel region of the first doping type, wherein the channel region extends from a boundary of the second well region to a boundary of the second doped region; and a gate of the depletion-mode MOS device. The switching power supply includes the composite device above. This invention can decrease the process complexity, reduce the chip area and cost, and may be applicable to high power scenarios.

Disclosed is a transistor device and a method for producing thereof. The transistor device includes at least one transistor cell, wherein the at least one transistor cell includes: a source region, a body region and a drift region in a semiconductor body; a gate electrode dielectrically insulated from the body region by a gate dielectric; a field electrode dielectrically insulated from the drift region by a field electrode dielectric; and a contact plug extending from a first surface of the semiconductor body to the field electrode and adjoining the source region and the body region.

A method for fabricating a semiconductor device is disclosed. A plurality of trenches is formed at a predetermined cell pitch in an upper surface portion of a substrate. A first insulation film is formed on the substrate. A gate electrode is formed within each trench, wherein the gate electrode partially fills each trench. A first conductivity type region is formed in the upper surface portion of the substrate between the trenches. A second conductivity type region is formed in a side surface of the substrate between the trenches and the first conductivity type region. A second insulation film is formed covering the gate electrode within each trench, wherein an upper surface of the second insulation film is positioned lower than an upper surface of the substrate. A source metal layer is formed on the second insulation film. The source metal layer is electrically connected to the first conductivity type region and the second conductivity type region.

A semiconductor device of the present invention is a semiconductor device having a semiconductor layer comprising a wide band gap semiconductor, wherein the semiconductor layer includes: a first conductivity-type source region, a second conductivity-type channel region and a first conductivity-type drain region, which are formed in this order from the surface side of the semiconductor layer; a source trench lying from the surface of the semiconductor layer through the source region and the channel region to the drain region; a gate insulating film formed so as to contact the channel region; a gate electrode facing the channel region with the gate insulating film interposed therebetween; and a first breakdown voltage holding region of a second conductivity type formed selectively on the side face or the bottom face of the source trench, and the semiconductor device includes a barrier formation layer, which is joined with the drain region in the source trench, for forming, by junction with the drain region, a junction barrier lower than a diffusion potential of a body diode formed by p-n junction between the channel region and the drain region.