A manufacturing method of a power MOSFET employs a hard mask film over a portion of the wafer surface as a polishing stopper, between two successive polishing steps. After embedded epitaxial growth is performed in a state where a hard mask film for forming trenches is present in at least a scribe region of a wafer, primary polishing is performed by using the hard mask film as a stopper, and secondary polishing is then performed after the hard mask film is removed.

A semiconductor device is provided that includes a silicon semiconductor body having a drift or base zone of net n-type doping. An n-type doping is partially compensated by 10% to 80% with p-type dopants. A net n-type doping concentration in the drift or base zone is in a range from 110.sup.13 cm.sup.3 to 110.sup.15 cm.sup.3. A portion of 5% to 75% of the n-type doping is made up of hydrogen related donors.

A semiconductor device includes a drift region extending from a first surface into a semiconductor portion. A body region between two portions of the drift region forms a first pn junction with the drift region. A source region forms a second pn junction with the body region. The pn junctions include sections perpendicular to the first surface. Gate structures extend into the body regions and include a gate electrode. Field plate structures extend into the drift region and include a field electrode separated from the gate electrode. A gate shielding structure is configured to reduce a capacitive coupling between the gate structures and a backplate electrode directly adjoining a second surface.

There are disclosed herein various implementations of a latch-up free power transistor. Such a device includes an insulated gate situated adjacent to a conduction channel in the power transistor, an emitter electrode in direct physical contact with the conduction channel, and a collector electrode in electrical contact with the conduction channel. The power transistor also includes an emitter layer in contact with a surface of a semiconductor substrate adjacent the conduction channel.

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.

A semiconductor device includes a semiconductor mesa that includes at least one body zone forming first pn junctions with source zones and a second pn junction with a drift zone. Electrode structures are on opposite sides of the semiconductor mesa. At least one of the electrode structures includes a gate electrode configured to control a charge carrier flow through the at least one body zone. In a separation region between the source zones, which are arranged along an extension direction of the semiconductor mesa, the semiconductor mesa includes at least one partial or complete constriction.

A semiconductor device of the present invention includes a semiconductor layer, a plurality of gate trenches formed in the semiconductor layer, a gate electrode filled via a gate insulating film in the plurality of gate trenches, an n.sup.+-type emitter region, a p-type base region, and an n.sup.-type drift region disposed, lateral to each gate trench, in order in a depth direction of the gate trench from a front surface side of the semiconductor layer, a p.sup.+-type collector region disposed on a back surface side of the semiconductor layer with respect to the n.sup.-type drift region, an emitter trench formed between the plurality of gate trenches adjacent to each other, and a buried electrode filled via an insulating film in the emitter trench, and electrically connected with the n.sup.+-type emitter region, and the emitter trench is disposed at an interval of 2 m or less via an n.sup.-type drift region with the gate trench.

In a general aspect, a method can include forming well region of one conductivity type in a semiconductor region of another conductivity type An interface between the well region and the semiconductor region can define a diode junction at a depth below an upper surface of the semiconductor region. The method can further include forming at least one dielectric region in the semiconductor region. A dielectric region of the at least one dielectric region can have an upper surface that is disposed in the well region at a depth in the semiconductor region that is above the depth of the diode junction; and a lower surface that is disposed in the semiconductor region at a depth in the semiconductor region that is the same depth as the diode junction or below the depth of the diode junction.

A semiconductor device includes a semiconductor layer, a plurality of gate trenches, a gate electrode in the plurality of gate trenches, an n.sup.+-type emitter region, a p-type base region, and an n.sup.-type drift region disposed, lateral to each gate trench, a p.sup.+-type collector region, a plurality of emitter trenches formed between the plurality of gate trenches, a buried electrode in the plurality of emitter trenches, and electrically connected with the n.sup.+-type emitter region, and a p-type floating region formed between the plurality of emitter trenches.

A semiconductor device includes field electrode structures extending in a direction vertical to a first surface in a semiconductor body. Cell mesas are formed from portions of the semiconductor body between the field electrode structures and include body zones that form first pn junctions with a drift zone. Gate structures between the field electrode structures control a current flow through the body zones. Auxiliary diode structures with a forward voltage lower than the first pn junctions are electrically connected in parallel with the first pn junctions, wherein semiconducting portions of the auxiliary diode structures are formed in the cell mesas.