A silicon carbide power device has: a die having a functional layer of silicon carbide and an edge area and an active area, surrounded by the edge area; gate structures formed on a top surface of the functional layer in the active area; and a gate contact pad for biasing the gate structures. The device also has an integrated resistor having a doped region, of a first conductivity type, arranged at the front surface of the functional layer in the edge area; wherein the integrated resistor defines an insulated resistance in the functional layer, interposed between the gate structures and the gate contact pad.

A MOSFET transistor device includes a functional layer of silicon carbide, having a first conductivity type. Gate structures are formed on a top surface of the functional layer and each includes a dielectric region and an electrode region. Body wells having a second conductivity type are formed within the functional layer, and the body wells are separated from one another by surface-separation regions. Source regions having the first conductivity type are formed within the body wells, laterally and partially underneath respective gate structures. Modified-doping regions are arranged in the surface-separation regions centrally thereto, underneath respective gate structures, in particular underneath the corresponding dielectric regions, and have a modified concentration of dopant as compared to the concentration of the functional layer.

A method for forming a semiconductor device having a tub. The method includes forming a substrate of a first conductivity type that includes a tub bottom layer of the tub. The tub bottom layer is of a second conductivity type that is opposite to the first conductivity type and has a tub bottom layer peak dopant concentration plane that is substantially away from a top surface of an initial substrate layer of the substrate for a predetermined tub bottom layer buried depth that is essentially greater than 0.5 m. The method can further include forming a plurality of tub sidewalls of the tub. The method can further include forming a high voltage transistor inside the tub.