A semiconductor device includes: a semiconductor substrate having opposing first and second main surfaces; a plurality of transistor cells each including a source region, a drift zone, a body region separating the source region from the drift zone, a field plate trench extending into the drift zone and including a field plate, and a planar gate on the first main surface and configured to control current through a channel of the body region; a drain region at the second main surface; and a diffusion barrier structure including alternating layers of Si and oxygen-doped Si and a Si capping layer on the alternating layers of Si and oxygen-doped Si. The diffusion barrier structure may be interposed between body regions of adjacent transistor cells and/or extend along the channel of each transistor cell and/or vertically extend in the semiconductor substrate between adjacent field plate trenches.

A power semiconductor device includes an active cell region with a drift region of a first conductivity type, a plurality of IGBT cells arranged within the active cell region, each of the IGBT cells includes at least one trench that extends into the drift, an edge termination region surrounding the active cell region, a transition region arranged between the active cell region and the edge termination region, at least some of the IGBT cells are arranged within or extend into the transition region, a barrier region of a second conductivity type, the barrier region is arranged within the active cell region and in contact with at least some of the trenches of the IGBT cells and does not extend into the transition region, and a first load terminal and a second load terminal, the power semiconductor device is configured to conduct a load current along a vertical direction between.

A method of processing a power semiconductor device includes: providing a semiconductor body with a drift region of a first conductivity type; forming a plurality of trenches extending into the semiconductor body along a vertical direction and arranged adjacent to each other along a first lateral direction; providing a mask arrangement at the semiconductor body, the mask arrangement having a lateral structure according to which some of the trenches are exposed and at least one of the trenches is covered by the mask arrangement along the first lateral direction; forming, below bottoms of the exposed trenches, a plurality of doping regions of a second conductivity type complementary to the first conductivity type; removing the mask arrangement; and extending the plurality of doping regions in parallel to the first lateral direction such that the plurality of doping regions overlap and form a barrier region of the second conductivity type adjacent to the bottoms of the exposed trenches.

A semiconductor device includes first and second trenches, and a first layer provided therebetween, in a principal surface of a semiconductor substrate, a second layer in contact with and sandwiching the first trench with the first layer, a third layer provided under the second layer and in contact with the second layer and the first trench, a fourth layer provided under and in contact with the third layer but separated from the first trench, and a fifth layer provided in the principal surface and sandwiching the second trench with the first layer. The second and fourth layers are semiconductors of a first conductivity type, and the first, third, and fifth layers are semiconductors of a second conductivity type. A gate trench electrode is provided inside the first trench via the insulating film, and an emitter trench electrode is provided inside the second trench via the insulating film.

A semiconductor device includes a semiconductor layer structure of a wide band-gap semiconductor material. The semiconductor layer structure includes a drift region having a first conductivity type and a well region having a second conductivity type. A plurality of segmented gate trenches extend in a first direction in the semiconductor layer structure. The segmented gate trenches include respective gate trench segments that are spaced apart from each other in the first direction with intervening regions of the semiconductor layer structure therebetween. Related devices and fabrication methods are also discussed.

A semiconductor device includes a source region and a drain region of a first conductivity type, a body region of a second conductivity type between the source region and the drain region, a gate configured to control current through a channel of the body region, a drift zone of the first conductivity type between the body region and the drain region, a superjunction structure formed by a plurality of regions of the second conductivity type laterally spaced apart from one another by intervening regions of the drift zone, and a diffusion barrier structure disposed along sidewalls of the regions of the second conductivity type of the superjunction structure. The diffusion barrier structure includes alternating layers of Si and oxygen-doped Si and a Si capping layer on the alternating layers of Si and oxygen-doped Si.

An embodiment relates to a method for manufacturing a semiconductor device. The method includes providing a semiconductor body including a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type interposed between the first semiconductor region and a first surface of the semiconductor body. The method further includes forming a first contact layer over the first surface of the semiconductor body. The first contact layer forms a direct electrical contact to the second semiconductor region. The method further includes forming a contact trench extending into the semiconductor body by removing at least a portion of the second semiconductor region. The method further includes forming a second contact layer in the contact trench. The second contact layer is directly electrically connected to the semiconductor body at a bottom side of the contact trench.

A method forms a part of a power semiconductor device. The method includes homoepitaxially forming two silicon carbide layers on a first side of a silicon carbide substrate and forming a pattern of pits on a second side of the silicon carbide substrate. The two layers include a buffer layer, on the first side of the silicon carbide substrate, and have a same doping type of the silicon carbide substrate and a doping concentration equal to or greater than 10.sup.17 cm.sup.−3 in order to increase the quality of at least one subsequent SiC layer. The two layers include an etch stopper layer, being deposited on the buffer layer and has a same doping type as the buffer layer but a lower doping concentration in order to block a trenching process. The pattern of pits, obtained by electrochemical etching, extends completely thorough the silicon carbide substrate and the buffer layer.

An insulated gate bipolar transistor includes a source electrode, a collector electrode, a source layer, a base layer, a drift layer and a collector layer. Trench gate electrodes extend through the base layer into the drift layer. A channel is located between the source layer, the base layer and the drift layer. A trench Schottky electrode is adjacent to one of the trench gate electrodes and includes an electrically conductive Schottky layer arranged lateral to the base layer and extends through the base layer into the drift layer. The Schottky layer is electrically connected to the source electrode. Collection areas are located in the drift layer at a respective trench gate electrode bottom of the trench gate electrodes or of the trench Schottky electrode. The Schottky layer forms a Schottky contact to the collection area at a contact area.

A MOS cell based on a simple and self-aligned process is provides a planar cell forming a horizontal MOS channel, and a plurality of trench regions, which are arranged at an angle with respect to the longitudinal direction of the planar cells. The new cell concept can adopt both planar MOS channels and Trench MOS channels in a single MOS cell structure, or planar MOS channels alone, while utilising the trenches to improve the current spreading of the planar MOS channels. Floating P-doped regions at the bottom of the trench regions protect the device against high peak electric fields. The orthogonal trench recesses are discontinued in their longitudinal direction to allow the planar channels to conduct electrons. The design can be applied to both IGBTs and MOSFETs based on silicon or wide bandgap materials.