A semiconductor portion of a semiconductor device includes a semiconductor layer with a drift zone of a first conductivity type and at least one impurity zone of a second, opposite conductivity type. The impurity zone adjoins a first surface of the semiconductor portion in an element area. A connection layer directly adjoins the semiconductor layer opposite to the first surface. At a distance to the first surface an overcompensation zone is formed in an edge area that surrounds the element area. The overcompensation zone and the connection layer have opposite conductivity types. In a direction vertical to the first surface, a portion of the drift zone is arranged between the first surface and the overcompensation zone. In case of locally high current densities, the overcompensation zone injects charge carriers into the semiconductor layer that locally counter a further increase of electric field strength and reduce the risk of avalanche breakdown.

A method of forming a manufacture includes forming a trench in a doped layer; and forming a gate dielectric layer along sidewalls of an upper portion of the trench. The method further includes forming a first conductive feature along sidewalls of the gate dielectric layer, wherein the first conductive feature has a first depth in the trench. The method further includes forming an insulating layer covering the first conductive feature and the first insulating layer. The method further includes forming a second conductive feature along sidewalls of the second insulating layer, wherein the second conductive feature has a second depth in the trench different from the first depth.

A trench MOSFET device includes a semiconductor layer of a first doping type. MOS transistor cells are in a body region of a second doping type in the semiconductor layer. The transistor cells include a first cell type including a first trench providing a first gate electrode or the first gate electrode is on the semiconductor surface between the first trench and a second trench, and a first source region is formed in the body region. The first gate electrode is electrically isolated from the first source region. A second cell type has a third trench providing a second gate electrode or the second gate electrode is on the semiconductor surface between the third trench and a fourth trench, and a second source region is in the body region. An electrically conductive member directly connects the second gate electrode, first source region and second source region together.

It is an object to provide the techniques capable of restraining avalanche breakdown at cells opposite to a corner portion of a gate pad. A MOSFET is provided with a corner cell, which is disposed in a region opposite to a corner portion of a gate pad in a planar view, and an internal cell, which is disposed in a region in the opposite side of the gate pad with respect to the corner cell. In a contour shape of the corner cell, a longest distance among distances each of which is shortest distance between a longest side and each of sides opposite to the longest side is equal to or less than two times of a length of one of equal sides or a short side of the internal cell.

According to one embodiment, the semiconductor body of the first portion includes a first semiconductor part and a second semiconductor part. The first semiconductor part extends in the stacking direction. The second semiconductor part is provided between the first semiconductor part and the first electrode layer, and has an end located closer to the first electrode layer side than the first semiconductor part. The first insulating film of the second portion includes a first insulating part and a second insulating part. The first insulating part extends in the stacking direction. The second insulating part is provided between the first insulating part and the second electrode layer, and has an end located closer to the second electrode layer side than the first insulating part.

Semiconductor devices and methods of forming the same are provided. A template layer is formed on a substrate, the template layer having a recess therein. A plurality of nanowires is formed in the recess. A gate stack is formed over the substrate, the gate stack surrounding the plurality of nanowires.

A semiconductor apparatus that has a first parallel pn-layer formed between an active region and an n.sup.+-drain region. A peripheral region is provided with a second parallel pn-layer, which has a repetition pitch narrower than the repetition pitch of the first parallel pn-layer. An n.sup.-surface region is formed between the second parallel pn-layer and a first main surface. On the first main surface side of the n.sup.-surface region, a plurality of p-guard ring regions are formed to be separated from each other. A field plate electrode is connected electrically to the outermost p-guard ring region among the p-guard ring regions. A channel stopper electrode is connected electrically to an outermost peripheral p-region of the peripheral region.

First polysilicon (poly-1) is deposited into deep trenches that have been formed in a substrate. A first polysilicon polishing process is performed to planarize the exposed surfaces of the poly-1 so that the surfaces are flush with adjacent surfaces. Then, shallow trenches are formed in the substrate between the deep trenches, and second polysilicon (poly-2) is deposited into the shallow trenches. A second polysilicon polishing process is performed to planarize the exposed surface of the poly-2 so that the surface is flush with adjacent surfaces. Metal contacts to the poly-1 and the poly-2 are then formed.

The semiconductor device includes: a plurality of interlayer insulation films, each interlayer insulation film covering a front surface of a corresponding one of the gate electrodes and protruding from the front surface of the semiconductor substrate; the first metal film covering the front surface of the semiconductor substrate and plurality of the interlayer insulation films; and the protective insulation film covering a part of the first metal film. In a cross-section traversing the plurality of trenches, the end of the protective insulation film is above one of the interlayer insulation films, and a width of the one of the interlayer insulation films that is below the end of the protective insulation film is wider than widths of other interlayer insulation films.

A semiconductor device comprises a silicon carbide based semiconductor layer structure that includes a drift layer having a first conductivity type, a gate trench that extends to a first depth into an upper surface of the semiconductor layer structure, a gate electrode in the gate trench, a support shield trench that extends to a second depth into the upper surface of the semiconductor layer structure, where the second depth is less than the first depth, and a source metallization layer on the upper surface of the semiconductor layer structure and extending into the support shield trench.