A semiconductor substrate has a trench extending from a front surface and including a lower part and an upper part. A first insulation layer lines the lower part of the trench, and a first conductive material in the lower part is insulated from the semiconductor substrate by the first insulating layer to form a field plate electrode of a transistor. A second insulating layer lines sidewalls of the upper part of said trench. A third insulating layer lines a top surface of the first conductive material at a bottom of the upper part of the trench. A second conductive material fills the upper part of the trench. The second conductive material forms a gate electrode of the transistor that is insulated from the semiconductor substrate by the second insulating layer and further insulated from the first conductive material by the third insulating layer.

A method includes forming a hard mask over an epitaxy layer of a substrate; forming a patterned mask over the hard mask; etching the hard mask and the epitaxy layer to form a trench in the epitaxy layer, in which a remaining portion of the hard mask covers a topmost surface of the epitaxy layer, and the trench exposes a sidewall of the epitaxy layer; forming a P-well region by directing p-type ion beams into the trench along an oblique direction that is non-parallel to a normal line of the topmost surface of the epitaxy layer, in which the topmost surface of the epitaxy layer is protected from the p-type ion beams by the remaining portion of the hard mask during directing the p-type ion beams into the trench; and after directing the p-type ion beams into the trench, forming a gate structure in the trench.

A method includes forming a hard mask over an epitaxy layer of a substrate; forming a patterned mask over the hard mask; etching the hard mask and the epitaxy layer to form a trench in the epitaxy layer, in which a remaining portion of the hard mask covers a topmost surface of the epitaxy layer, and the trench exposes a sidewall of the epitaxy layer; forming a P-well region by directing p-type ion beams into the trench along an oblique direction that is non-parallel to a normal line of the topmost surface of the epitaxy layer, in which the topmost surface of the epitaxy layer is protected from the p-type ion beams by the remaining portion of the hard mask during directing the p-type ion beams into the trench; and after directing the p-type ion beams into the trench, forming a gate structure in the trench.

A semiconductor device that allows easy hole extraction is provided. The semiconductor device includes: a semiconductor substrate having drift and base regions; a transistor portion formed in the semiconductor substrate; and a diode portion formed adjacent to the transistor portion and in the semiconductor substrate. In the transistor portion and the diode portion: a plurality of trench portions each arrayed along a predetermined array direction; and a plurality of mesa portions formed between respective trench portions are formed, among the plurality of mesa portions, at least one boundary mesa portion at a boundary between the transistor portion and the diode portion includes a contact region at an upper surface of the semiconductor substrate and having a concentration higher than that of the base region, and an area of the contact region at the boundary mesa portion is greater than an area of the contact region at another mesa portion.

A semiconductor device that allows easy hole extraction is provided. The semiconductor device includes: a semiconductor substrate having drift and base regions; a transistor portion formed in the semiconductor substrate; and a diode portion formed adjacent to the transistor portion and in the semiconductor substrate. In the transistor portion and the diode portion: a plurality of trench portions each arrayed along a predetermined array direction; and a plurality of mesa portions formed between respective trench portions are formed, among the plurality of mesa portions, at least one boundary mesa portion at a boundary between the transistor portion and the diode portion includes a contact region at an upper surface of the semiconductor substrate and having a concentration higher than that of the base region, and an area of the contact region at the boundary mesa portion is greater than an area of the contact region at another mesa portion.

Disclosed is a power device, such as power MOSFET, and method for fabricating same. The device includes an upper trench situated over a lower trench, where the upper trench is wider than the lower trench. The device further includes a trench dielectric inside the lower trench and on sidewalls of the upper trench. The device also includes an electrode situated within the trench dielectric. The trench dielectric of the device has a bottom thickness that is greater than a sidewall thickness.

Disclosed is a power device, such as power MOSFET, and method for fabricating same. The device includes an upper trench situated over a lower trench, where the upper trench is wider than the lower trench. The device further includes a trench dielectric inside the lower trench and on sidewalls of the upper trench. The device also includes an electrode situated within the trench dielectric. The trench dielectric of the device has a bottom thickness that is greater than a sidewall thickness.

A semiconductor device includes a substrate, a nitride semiconductor layer formed on the substrate, a source electrode and a drain electrode formed in the nitride semiconductor layer. The source electrode and drain electrode are arranged side by side in a first direction. A gate electrode is formed on the nitride semiconductor layer between the source electrode and the drain electrode. A first protective film is formed on the nitride semiconductor layer, and covers the first protective film covering the source electrode, the drain electrode, and the gate electrode. A source field plate is formed on the first protective film between the gate electrode and the drain electrode in a plan view. A dielectric-breakdown inhibition portion includes a part positioned between an end of the source field plate and an end of the drain electrode in a sectional view, and inhibits dielectric breakdown of the first protective film.

An apparatus is provided which comprises: a substrate, the substrate comprising crystalline material, a first set of one or more contacts on a first substrate surface, a second set of one or more contacts on a second substrate surface, the second substrate surface opposite the first substrate surface, a first via through the substrate coupled with a first one of the first set of contacts and with a first one of the second set of contacts; a second via through the substrate coupled with a second one of the first set of contacts and with a second one of the second set of contacts, a trench in the substrate from the first substrate surface toward the second substrate surface, wherein the trench is apart from, and between, the first via and the second via, and dielectric material filling the trench. Other embodiments are also disclosed and claimed.

An apparatus is provided which comprises: a substrate, the substrate comprising crystalline material, a first set of one or more contacts on a first substrate surface, a second set of one or more contacts on a second substrate surface, the second substrate surface opposite the first substrate surface, a first via through the substrate coupled with a first one of the first set of contacts and with a first one of the second set of contacts; a second via through the substrate coupled with a second one of the first set of contacts and with a second one of the second set of contacts, a trench in the substrate from the first substrate surface toward the second substrate surface, wherein the trench is apart from, and between, the first via and the second via, and dielectric material filling the trench. Other embodiments are also disclosed and claimed.