A switching device including: a body of semiconductor material, which has a first conductivity type and is delimited by a front surface; a contact layer of a first conductive material, which extends in contact with the front surface; and a plurality of buried regions, which have a second conductivity type and are arranged within the semiconductor body, at a distance from the contact layer.

A first silicon controlled rectifier has a breakdown voltage in a first direction and a breakdown voltage in a second direction. A second silicon controlled rectifier has a breakdown voltage with a higher magnitude than the first silicon controlled rectifier in the first direction, and a breakdown voltage with a lower magnitude than the first silicon controlled rectifier in the second direction. A bidirectional electrostatic discharge (ESD) structure utilizes both the first silicon controlled rectifier and the second silicon controlled rectifier to provide bidirectional protection.

A trench IGBT includes a floating P well and a floating N+ well that extends down into the floating P well. A bottom surface of the floating P well has a novel waved contour so that it has thinner portions and thicker portions. When the IGBT is on, electrons flow from an N+ emitter, vertically through a channel along a trench sidewall, and to an N type drift layer. Additional electrons flow through the channel but then pass under the trench, through the floating P well to the floating N+ well, and laterally through the floating N+ well. NPN transistors are located at thinner portions of the floating P type well. The NPN transistors inject electrons from the floating N+ type well down into the N drift layer. The extra electron injection reduces V.sub.CE(SAT). The waved contour can be made without adding any masking step to an IGBT manufacturing process.

A semiconductor device includes: a semiconductor substrate having a main surface; a first insulating film formed in a convex shape and provided on the main surface of the semiconductor substrate; a first diffusion layer formed on the semiconductor substrate and provided to surround the first insulating film formed in a convex shape, the first diffusion layer being different in conductivity type from the semiconductor substrate; a first conductive layer formed so as to extend across the first insulating film formed in a convex shape, the first conductive layer forming a fuse element; and a second insulating film provided on the first conductive layer.

A method of manufacturing a silicon carbide semiconductor device is provided. The method suppresses the increase in the number of manufacturing steps and is capable of suppressing the degradation of ohmic characteristics of an alloy layer with respect to a semiconductor substrate. The method includes a step of forming a metal layer made of a first metal on a semiconductor substrate made of silicon carbide; a step of forming a metal nitride film obtained by nitriding a second metal on the metal layer; a step of directing a laser light through the metal nitride film to form a layer of an alloy of silicon carbide in the semiconductor substrate and the first metal in the metal layer; and a step of forming an electrode on the metal nitride film.

A linear active cell region is formed from a plurality of divided active cell regions arranged apart from each other in a second direction (y direction). The linear hole collector cell region is formed from a plurality of divided hole collector cell regions arranged apart from each other in the second direction (y direction). A P-type floating region is formed in a semiconductor substrate between the linear active cell region and the linear hole collector cell region adjacent to each other in a first direction (x direction), between the divided active cell regions adjacent to each other in the second direction (y direction), and between the divided hole collector cell regions adjacent to each other in the second direction (y direction).

Provided is a semiconductor device manufacturing method. The device has a substrate including one and another surfaces. A first semiconductor region of a first conductivity type is formed in the substrate. A second conductivity type, second semiconductor region is provided in a first surface layer, that includes the one surface, of the substrate. A first electrode is in contact with the second semiconductor region to form a junction therebetween. A first conductivity type, third semiconductor region is provided in a second surface layer, that includes the another surface, of the substrate. The third semiconductor region has a higher impurity concentration than the first semiconductor region. A fourth semiconductor region of the second conductivity type is provided in the first semiconductor region at a location deeper than the third semiconductor region from the another surface. A second electrode is in contact with the third semiconductor region.

This invention involves a fabrication method of fast recovery diode, which includes following steps: growing a sacrificial oxide layer on a surface of an N substrate; forming a P type doped field-limiting ring region on the substrate; forming a P type doped anode region on the substrate; removing the sacrificial oxide layer; annealing the substrate to form a PN junction; implanting oxygen into the surface of the substrate by ion implantation; annealing the substrate to form a silicon dioxide layer on the surface of the substrate; removing the silicon dioxide layer; forming an anode electrode and a cathode electrode of the fast recovery diode. The method eliminates the curved parts near the silicon surface of the profile of PN junction, decreases electric field intensity at the surface of the substrate, therefore increases the breakdown voltage and reliability of the fast recovery diode.

A method of manufacturing a semiconductor device includes forming electrode trenches in a semiconductor substrate between semiconductor mesas that separate the electrode trenches, the semiconductor mesas including portions of a drift layer of a first conductivity type and a body layer of a second, complementary conductivity type between a first surface of the semiconductor substrate and the drift layer, respectively. The method further includes forming isolated source zones of the first conductivity type in the semiconductor mesas, the source zones extending from the first surface into the body layer. The method also includes forming separation structures in the semiconductor mesas between neighboring source zones arranged along an extension direction of the semiconductor mesas, the separation structures forming partial or complete constrictions of the semiconductor mesa, respectively.

A performance of a semiconductor device is improved. A semiconductor device includes two element portions and an interposition portion interposed between the two element portions. The interposition portion includes a p-type body region formed in a part of a semiconductor layer, the part being located between two trenches, and two p-type floating regions formed in two respective parts of the semiconductor layer, the two respective portions being located on both sides of the p-type body region via the two respective trenches. A lower end of the p-type floating region is arranged on a lower side with reference to a lower end of the p-type body region.