A silicon carbide semiconductor device includes a silicon carbide layer 32 of a first conductivity type, a silicon carbide layer 36 of a second conductivity type, a gate trench 20, a gate electrode 79 provided in the gate trench 20, and a protection trench 10 formed to a greater depth than the gate trench 20. A region in the horizontal direction that includes both the gate trench 20 and a protection trench 10 that surrounds only a part of the gate trench 20 in the horizontal direction is a cell region, and a region in the horizontal direction that includes a protection trench 10 and in which a gate pad 89 or a lead electrode connected to the gate pad 89 is disposed is a gate region.

A method of manufacturing a semiconductor device includes forming a cavity in a first semiconductor layer formed on a semiconducting base layer, the cavity extending from a process surface of the first semiconductor layer at least down to the base layer, forming a recessed mask liner on a portion of a sidewall of the cavity distant to the process surface or a mask plug in a portion of the cavity distant to the process surface, and growing a second semiconductor layer on the process surface by epitaxy, the second semiconductor layer spanning the cavity.

A semiconductor device includes a termination trench surrounding a region in which a plurality of gate trenches is provided; a p-type lower end region being in contact with a lower end of the termination trench; a p-type outer circumference region being in contact with the termination trench from an outer circumferential side and exposed on a surface of the semiconductor device; a plurality of guard ring regions of a p-type provided on an outer circumferential side of the p-type outer circumference region and exposed on the surface; and an n-type outer circumference region separating the p-type outer circumference region from the guard ring regions and separating the guard ring regions from each another.

A method for forming a semiconductor device includes forming an electrical structure at a main surface of a semiconductor substrate and carrying out an anodic oxidation of a back side surface region of a back side surface of the semiconductor substrate to form an oxide layer at the back side surface of the semiconductor substrate. Additionally, the method includes connecting a carrier substrate to the oxide layer and processing a back side of the semiconductor substrate.

There are provided a high-quality semiconductor device having stable characteristics and a method for manufacturing such a semiconductor device. The semiconductor device includes: a substrate having a main surface; and a silicon carbide layer formed on the main surface of the substrate and including a side surface inclined relative to the main surface. The side surface substantially includes a {03-3-8} plane. The side surface includes a channel region.

A semiconductor device includes stripe-shaped gate trench formed in one major surface of n-type drift layer, gate trench including gate polysilicon formed therein, and gate polysilicon being connected to a gate electrode; p-type base layer formed selectively in mesa region between adjacent gate trenches, p-type base layer including n-type emitter layer and connected to emitter electrode; one or more dummy trenches formed between p-type base layers adjoining to each other in the extending direction of gate trenches; and electrically conductive dummy polysilicon formed on an inner side wall of dummy trench with gate oxide film interposed between dummy polysilicon and dummy trench, dummy polysilicon being spaced apart from gate polysilicon. Dummy polysilicon may be connected to emitter electrode. The structure according to the invention facilitates providing an insulated-gate semiconductor device, the Miller capacitance of which is small, even when the voltage applied between the collector and emitter is low.

Various improvements in vertical transistors, such as IGBTs, are disclosed. The improvements include forming periodic highly-doped p-type emitter dots in the top surface region of a growth substrate, followed by growing the various transistor layers, followed by grounding down the bottom surface of the substrate, followed by a wet etch of the bottom surface to expose the heavily doped p+ layer. A metal contact is then formed over the p+ layer. In another improvement, edge termination structures utilize p-dopants implanted in trenches to create deep p-regions for shaping the electric field, and shallow p-regions between the trenches for rapidly removing holes after turn-off. In another improvement, a dual buffer layer using an n-layer and distributed n+ regions improves breakdown voltage and saturation voltage. In another improvement, p-zones of different concentrations in a termination structure are formed by varying pitches of trenches. In another improvement, beveled saw streets increase breakdown voltage.

A semiconductor component is disclosed. One embodiment includes a semiconductor body including a first semiconductor layer having at least one active component zone, a cell array with a plurality of trenches, and at least one cell array edge zone. The cell array edge zone is only arranged in an edge region of the cell array, adjoining at least one trench of the cell array, and being at least partially arranged below the at least one trench in the cell array.

In an active region, p.sup.+ regions are selectively disposed in a surface layer of an n.sup. drift layer on an n.sup.+ semiconductor substrate. A p-base layer is disposed on surfaces of the n.sup. drift layer and the P.sup.+ regions, and an MOS structure is disposed on the p-base layer. In another portion of the active region, a p.sup.+ region is disposed to be in contact with the source electrode on the p.sup.+ regions. In a breakdown voltage structure region (100), a JTE structure having at least a P.sup. region is disposed separately from the P.sup.+ regions and the p-base layer, to surround the active region. The P.sup. region is electrically in contact with the P.sup.+ region in a portion in which the MOS structure is not formed, in the vicinity of the boundary between the active region and the breakdown voltage structure region.

A semiconductor device having a plurality of transistors includes a termination area that features a transistor with an asymmetric gate.