In a contact hole of an interlayer insulating film, a tungsten film forming a contact plug is embedded via a barrier metal. The interlayer insulating film is formed by sequentially stacked HTO and BPSG films. The BPSG film has an etching rate faster than that of the HTO film with respect to a hydrofluoric acid solution used in wet etching of preprocessing before formation of the barrier metal. After the contact hole is formed in the interlayer insulating film, a width of an upper portion of the contact hole at the BPSG film is increased in a step-like shape, to be wider than a width of a lower portion at the HTO film by the wet etching before the formation of the barrier metal, whereby an aspect ratio of the contact hole is reduced. Thus, size reductions and enhancement of the reliability may be realized.

An insulated gate power semiconductor device (1a), comprises in an order from a first main side (20) towards a second main side (27) opposite to the first main side (20) a first conductivity type source layer (3), a second conductivity type base layer (4), a first conductivity type enhancement layer (6) and a first conductivity type drift layer (5). The insulated gate power semiconductor device (1a) further comprises two neighbouring trench gate electrodes (7) to form a vertical MOS cell sandwiched between the two neighbouring trench gate electrodes (7). At least a portion of a second conductivity type protection layer (8a) is arranged in an area between the two neighbouring trench gate electrodes (7), wherein the protection layer (8a) is separated from the gate insulating layer (72) by a first conductivity type channel layer (60a; 60b) extending along the gate insulating layer (72).

A semiconductor device includes a semiconductor layer that has a first surface and a second surface, a trench that is formed at the first surface of the semiconductor layer and that extends in a first direction, an element portion that has a first-conductivity-type first region, a second-conductivity-type second region, and a third-conductivity-type third region that are formed in order along a depth direction of the trench from the first surface of the semiconductor layer, a gate insulating film formed at an inner surface of the trench, and a gate electrode that is embedded in the trench and that faces the first region, the second region, and the third region through the gate insulating film.

The disclosure provides a semiconductor apparatus capable of keeping a semiconductor characteristics and realizing excellent semiconductor properties even when using an n type semiconductor (gallium oxide, for example) having a low loss at a high voltage and having much higher dielectric breakdown electric field strength than SiC. A semiconductor apparatus including at least an n type semiconductor layer and a p+ type semiconductor layer, wherein the n type semiconductor layer includes a crystalline oxide semiconductor (gallium oxide, for example) containing a metal of Group 13 of the periodic table as a main component, and the p+ type semiconductor layer includes a crystalline oxide semiconductor (iridium oxide, for example) containing a metal of Group 9 of the periodic table as a main component.

A vertical IGBT device is disclosed. The vertical IGBT structure includes an active MOSFET cell array formed in an active region at a front side of a semiconductor substrate of a first conductivity type. One or more column structures of a second conductivity type concentrically surround the active MOSFET cell array. Each column structure includes a column trench and a deep column region. The deep column region is formed by implanting implants of the second conductivity type into the semiconductor substrate through the floor of the column trench. Dielectric side wall spacers are formed on the trench side walls except a bottom wall of the trench and the column trench is filled with poly silicon of the second conductivity type. One or more column structures are substantially deeper than the active MOSFET cell array.

To enhance the performance of a semiconductor device. Gate electrodes extending in a Y direction and applied with a gate potential, and emitter regions and base regions both applied with an emitter potential are formed in an active cell area. The plural emitter regions are formed so as to be separated from each other in the Y direction by the base regions. A plurality of hole discharge cell areas having a ring-shaped gate electrode applied with an emitter potential are formed within an inactive cell area. The hole discharge cell areas are arranged to be separated from each other along the Y direction. Thus, an input capacitance of an IGBT is reduced, and a switching loss at turn on of the IGBT is improved.

According to an embodiment, a semiconductor device 1 includes a semiconductor substrate 50 including an upper surface, a trench electrode 22 provided inside a trench 20 formed on the upper surface, and a trench insulating film 21 provided between the trench electrode 22 and the semiconductor substrate 50. The semiconductor substrate 50 includes a first semiconductor layer of a first conductivity type, a lower end of the trench electrode 22 reaching the first semiconductor layer, a deep layer 19 of a second conductivity type partially provided on the first semiconductor layer in contact with the trench insulating film 21, a second semiconductor layer of the second conductivity type provided on the first semiconductor layer and on the deep layer 19 in contact with the trench insulating film 21, and a third semiconductor layer of the first conductivity type provided on the second semiconductor layer above the deep layer 19.

An insulated-gate semiconductor device, which has trenches arranged in a chip structure, the trenches defining both sidewalls in a first and second sidewall surface facing each other, includes: a first unit cell including a main-electrode region in contact with a first sidewall surface of a first trench, a base region in contact with a bottom surface of the main-electrode region and the first sidewall surface, a drift layer in contact with a bottom surface of the base region and the first sidewall surface, and a gate protection-region in contact with the second sidewall surface and a bottom surface of the first trench; and a second unit cell including an operation suppression region in contact with a first sidewall surface and a second sidewall surface of a second trench, wherein the second unit cell includes the second trench located at one end of an array of the trenches.

Semiconductor devices and methods of fabrication are provided. The semiconductor device includes a Charge Injection Controlled (CIC) Fast Recovery Diode (FRD) to control charge injection by lowering carrier storage. The device can have a first conductivity type semiconductor substrate, and a drift region that includes a doped buffer region, a doped middle region and a doped field stop region or carrier storage region. The device can also include a second conductivity type shield region including a deep junction encircling (or substantially laterally beneath) the buffer region and a second conductivity type shallow junction anode region in electrical contact with a second conductivity type anode electrode. The deep junction can have a range of doping concentrations surrounding the buffer regions to deplete buffer charge laterally as well as vertically to prevent premature device breakdown. The first conductivity type may be N type and the second conductivity type may be P type.

A method of manufacturing a silicon carbide device includes: forming a trench in a process surface of a silicon carbide substrate that has a body layer forming second pn junctions with a drift layer structure, wherein the body layer is between the process surface and the drift layer structure and wherein the trench exposes the drift layer structure; implanting dopants through a bottom of the trench to form a shielding region that forms a first pn junction with the drift layer structure; forming dielectric spacers on sidewalls of the trench; and forming a buried portion of an auxiliary electrode in a bottom section of the trench, the buried portion adjoining the shielding region.