A cell structure of a silicon carbide MOSFET device, comprising a drift region (3) located on a substrate layer (2), a second conducting type well region (4) and a first JFET region (51) that are located in the drift region (3), an enhancement region located within a surface of the well region (4), a gate insulating layer (8) located on a first conducting type enhancement region (6), the well region (4) and the first JFET region (51) and being in contact therewith at the same time, a gate (9) located on the gate insulating layer, source metal (10) located on the enhancement region, Schottky metal (11) located on a second conducting type enhancement region (7) and the drift region (3), a second JFET region (52) located on a surface of the drift region (3) between the Schottky metals (11), and drain metal (12).

A semiconductor device includes a semiconductor substrate, a top electrode in contact with a top surface of the semiconductor substrate, a bottom electrode in contact with a bottom surface of the semiconductor substrate, and an oxide film in contact with the top surface of the semiconductor substrate. The semiconductor substrate includes an element region and an outer peripheral region. The element region is a region where the top electrode is in contact with the top surface of the semiconductor substrate. The outer peripheral region is a region where the oxide film is in contact with the top surface of the semiconductor substrate, and is located between the element region and an outer peripheral end surface of the semiconductor substrate. The element region includes a semiconductor element connected between the top electrode and the bottom electrode. The outer peripheral region includes surface high-voltage-breakdown regions, deep high-voltage-breakdown regions, and a drift region.

A power semiconductor device includes a semiconductor substrate, a drift layer, a well region, a doped region, two dummy trenches, a gate structure and a dielectric layer. The semiconductor substrate is doped to have a first conductive channel. The drift layer on the semiconductor substrate is doped to have the first conductive channel. The well region on the drift layer is doped to have a second conductive channel having a polarity opposite to that of the first conductive channel. The doped region on the well region is doped to have the first conductive channel. Two dummy trenches pass through the doped region and the well region. Each of the dummy trenches has a dummy gate. The gate structure has a real gate and is between the dummy trenches. The dielectric layer isolates the dummy gate and the real gate from the doped region, the well region and the drift layer.

A semiconductor device according to one or more embodiments is disclosed. A first semiconductor region includes a first semiconductor region, a second semiconductor region, a third semiconductor region, a first trench and a fourth semiconductor region. A second semiconductor region includes a fifth semiconductor region, a sixth semiconductor region, a second trench, and a second inner trench electrode. A dummy region includes a seventh semiconductor region that is arranged on the first semiconductor region between the first semiconductor region and the second semiconductor region, a third trench penetrating the seventh semiconductor region in a depth direction; and a third inner trench electrode electrically connected to the first inner trench electrode through a third insulating film in the third trench.

A semiconductor device with an active transistor cell comprising a p-doped first and second base layers, surrounding an n type source region, the device further comprising a plurality of first gate electrodes embedded in trench recesses, has additional fortifying p-doped layers embedding the opposite ends of the trench recesses. The additional fortifying layers do not affect the active cell design in terms of cell pitch i.e., the design rules for transistor cell spacing, or hole drainage between the transistor cells, but reduce the gate-collector parasitic capacitance of the semiconductor, hence leading to optimum low conduction and switching losses. To further reduce the gate-collector capacitance, the trench recesses embedding the first gate electrodes can be formed with thicker insulating layers in regions that do not abut the first base layers, so as not to negatively impact the value of the threshold voltage.

A semiconductor device according to an embodiment includes first to third semiconductor regions, a structure body, a gate electrode, and a high resistance part. The structure body includes an insulating part and a conductive part. The insulating part is arranged with the third semiconductor region, the second semiconductor region, and a portion of the first semiconductor region. The conductive part is located in the insulating part. The conductive part includes a portion facing the first semiconductor region. The high resistance part is located in the first semiconductor region and has a higher electrical resistance than the first semiconductor region. A plurality of the structure bodies includes first to third structure bodies. The second and third structure bodies are next to the first structure body. The high resistance part overlaps a circle center of an imaginary circle passing through centers of the first to third structure bodies.

Provided is a semiconductor device including a portion which operates as a transistor, in which the transistor includes a gate trench portion to which a gate voltage is applied, an emitter region in contact with the gate trench portion, and a base region in contact with the gate trench portion, and a threshold voltage at which the transistor transits from an off state to an on state in an ambient temperature of 25 C. is larger than a half of a first voltage for turning on the transistor.

Trenches having a gate oxide layer are formed in the surface of a silicon wafer for vertical gates. Conductive doped polysilicon is then deposited in the trenches to form a relatively thin layer of doped polysilicon along the sidewalls. Thus, there is a central cavity surrounded by polysilicon. Next, the cavity is filled in with a much higher conductivity material, such as aluminum, copper, a metal silicide, or other conductor to greatly reduce the overall resistivity of the trenched gates. The thin polysilicon forms an excellent barrier to protect the gate oxide from diffusion from the inner conductor atoms. The inner conductor and the polysilicon conduct the gate voltage in parallel to lower the resistance of the gates, which increases the switching speed of the device. In another embodiment, a metal silicide is used as the first layer, and a metal fills the cavity.

A semiconductor device according to the present invention is provided with a gate trench that is formed in a semiconductor layer, and a gate electrode that is embedded in the gate trench, with an insulating layer interposed therebetween. The gate trench includes a first outer peripheral gate trench section that is provided in an outer peripheral region thereof, and a second outer peripheral gate trench section that is provided outward of the first outer peripheral gate trench section. The semiconductor device is provided with, in the semiconductor layer, a first floating trench that is formed in a region between the first outer peripheral gate trench section and the second outer peripheral gate trench section, and a first floating electrode that is embedded in the first floating trench, with an insulating layer interposed therebetween, and that is in an electrically floating state.

There are disclosed herein various implementations of an insulated-gate bipolar transistor (IGBT) with buried depletion electrode. Such an IGBT may include a collector at a bottom surface of a semiconductor substrate, a drift region having a first conductivity type situated over the collector, and a base layer having a second conductivity type opposite the first conductivity type situated over the drift region. The IGBT also includes a plurality of deep insulated trenches with a buried depletion electrode and at least one gate electrode disposed therein. In addition, the IGBT includes an active cell including an emitter adjacent the gate electrode, and an implant zone, situated between adjacent deep insulated trenches. The implant zone is formed below the base layer and has the first conductivity type. In one implementation, the IGBT may also include a dummy cell neighboring the active cell.