A power semiconductor device includes, an active area that conducts load current between first and second load terminal structures, a drift region, and a backside region that includes, inside the active area, first and second backside emitter zones one or both of which includes: first sectors having at least one first region of a second conductivity type contacting the second load terminal structure and a smallest lateral extension of at most 50 m; and/or second sectors having a second region of the second conductivity type contacting the second load terminal structure and a smallest lateral extension of at least 50 m. The emitter zones differ by at least of: the presence of first and/or second sectors; smallest lateral extension of first and/or second sectors; lateral distance between neighboring first and/or second sectors; smallest lateral extension of the first regions; lateral distance between neighboring first regions within the same first sector.

A semiconductor device of embodiments includes: a semiconductor layer including a first semiconductor region of a first conductive type, a second semiconductor region of a second conductive type, and a third semiconductor region of the first conductive type; and a gate electrode. The second semiconductor region includes first, second, and third regions. The gate electrode includes first, second, and third portions. The first, second, and third portions face the first, second, and third regions, respectively. The first portion, the second portion, and the third portion contain a first material, a second material, and a third material, respectively. When the first conductive type is n-type, the work function of the first material and the third material are smaller than that of the second material. When the first conductive type is p-type, the work function of the first material and the third material are larger than that of the second material.

A semiconductor device in which short circuit capability can be improved while decline in overall current capability is suppressed. In the semiconductor device, a plurality of IGBTs (insulated gate bipolar transistors) arranged in a row in one direction over the main surface of a semiconductor substrate include an IGBT located at an extreme end in the one direction and an IGBT located more centrally than the IGBT located at the extreme end. The current capability of the IGBT located at the extreme end is higher than the current capability of the IGBT located centrally.

A method for manufacturing a silicon carbide semiconductor device includes steps below. A silicon carbide substrate having a first main surface and a second main surface opposite to the first main surface, the first main surface having a maximal diameter greater than 100 mm, is prepared. An impurity region is formed on a side of the first main surface of the silicon carbide substrate. In a plan view, a cover member is arranged on the side of the first main surface so as to cover at least the entire impurity region. The silicon carbide substrate is annealed at a temperature lower than a melting point of the cover member while the cover member is arranged on the side of the first main surface of the silicon carbide substrate.

Methods of maintaining a state of a memory cell without interrupting access to the memory cell are provided, including applying a back bias to the cell to offset charge leakage out of a floating body of the cell, wherein a charge level of the floating body indicates a state of the memory cell; and accessing the cell.

A transistor device having reduced electrical field at the gate oxide interface is disclosed. In one embodiment, the transistor device comprises a gate, a source, and a drain, wherein the gate is at least partially in contact with a gate oxide. The transistor device has a P+ region within a JFET region of the transistor device in order to reduce an electrical field on the gate oxide.

The present invention can reduce an on-resistance while suppressing reduction in a short circuit capacity. The present invention includes a SiC epitaxial layer, a well region, a source region, a channel resistance adjusting region, a gate electrode, an interlayer insulating film, a source electrode, and a drain electrode. The channel resistance adjusting region is sandwiched between the source region and the SiC epitaxial layer in a surface layer of the well region. The channel resistance adjusting region is a region in which a first impurity region is intermittently formed in a direction intersecting a direction in which the source region and the SiC epitaxial layer sandwich the channel resistance adjusting region.

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 superjunction semiconductor device includes a first semiconductor layer doped with a first conductivity type; an active region formed on the first semiconductor layer, the active region including a drift layer; and a termination region disposed to surround the active region, the termination region including a lower edge region disposed on a side surface of the drift layer and an upper edge region disposed on the lower edge region, wherein the upper edge region includes a lower charge balance region disposed on the lower edge region, the lower charge balance region having a second conductivity type different from the first conductivity type, and an upper charge balance region disposed on the lower charge balance region, the upper charge balance region having the first conductivity type.

A semiconductor device is provided, the semiconductor device including a base layer of a first conductivity type having a MOS gate structure formed on a front surface side thereof, a collector layer of a second conductivity type formed on a rear surface side of the base layer, and into which a first dopant and a second dopant which is different from the first dopant are implanted, and a collector electrode formed on a rear surface side of the collector layer, wherein an impurity concentration peak of the second dopant is at a deeper position from the rear surface of the collector layer than an impurity concentration peak of the first dopant, and magnitude of the impurity concentration peak of the second dopant is larger than 1/100 of magnitude of the impurity concentration peak of the first dopant.