A semiconductor device includes a first-conductivity-type drift region provided in a semiconductor substrate; a trench portion provided from an upper surface of the semiconductor substrate to an inside of the semiconductor substrate, and extending in a predetermined extending direction in a plane of the upper surface of the semiconductor substrate; a mesa portion provided in contact with the trench portion in an array direction orthogonal to the extending direction; a second-conductivity-type base region provided in the mesa portion above the drift region and in contact with the trench portion; and a second-conductivity-type floating region provided in the mesa portion below the base region, in contact with the trench portion, and provided in at least a part of the mesa portion in the array direction.

A voltage-controlled switching device includes a drain/drift structure formed in a semiconductor portion with a lateral cross-sectional area A.sub.Q, a source/emitter terminal, and an emitter channel region between the drain/drift structure and the source/emitter terminal. A resistive path electrically connects the source/emitter terminal and the emitter channel region. The resistive path has an electrical resistance of at least 0.1 m*cm.sup.2/A.sub.Q.

A voltage-controlled switching device includes a drain/drift region of a first conductivity type formed in a semiconductor portion. A channel region and the drain/drift region are in direct contact with each other. A source region of a second conductivity type and the channel region are in direct contact with each other. A gate electrode and the channel region are capacitively coupled and configured such that, in a an on-state of the voltage-controlled switching device, a first enhancement region of charge carriers corresponding to the first conductivity type forms in the channel region and band-to-band tunneling is facilitated between the source region and the first enhancement region.

Provided is a semiconductor device including: a semiconductor substrate provided with an active portion and an edge termination structure portion surrounding the active portion; an interlayer dielectric film provided above the semiconductor substrate; a protective film provided above the interlayer dielectric film; and a protruding portion provided farther from the active portion than the edge termination structure portion and protruding further than the interlayer dielectric film. The protruding portion is not covered with the protective film. The protective film is provided closer to the active portion than the protruding portion.

An embodiment includes a controller and a driver. The controller determines and sets either of a first mode or a second mode. The first mode is set when a direction of a current into a semiconductor element is a forward direction. The second mode is set when the direction of the current into the semiconductor element is a backward direction. The semiconductor includes a reverse conducting IGBT having dual gate electrodes. The diving unit generates independent gate signals for the dual gate electrodes in accordance with the setting of the controller. And the driver drives the dual gate electrodes as to shorten an off time of the semiconductor element in the first mode, and as to shorten a reverse recovery time in a diode operation of the semiconductor device in the second mode.

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.

Provided is a semiconductor device including a transistor portion and a diode portion arranged side by side with the transistor unit in a first direction, including a first mesa portion and a second mesa portion arranged farther away from the diode portion than the first mesa portion, wherein: the first mesa portion has a first region of the first conductivity type, provided in at least a partial region between a depth position of a lower end of the base region and a depth position of a lower end of the trench portion; and the second mesa portion has a second region of the first conductivity type, provided in at least a partial region between the depth position of the lower end of the base region and a depth position of the lower end of the trench portion, with a dose amount greater than that of the first region.

A semiconductor device including a gate electrode layer embedded in a gate trench, a contact trench including a first intersection region intersecting the gate trench, and an emitter contact electrode layer embedded in the contact trench, in which gate electrode recess portions are formed in the first intersection region in the gate trench and a peripheral portion of the first intersection region, a gate covering insulating layer is embedded in the gate electrode recess portion, and the emitter region is formed deeper than an upper surface of the gate electrode layer in the periphery of the first intersection region.

Provided is a semiconductor device comprising a semiconductor substrate that includes a transistor region; an emitter electrode that is provided on the semiconductor substrate; a first dummy trench portion that is provided on the transistor region of the semiconductor substrate and includes a dummy conducting portion that is electrically connected to the emitter electrode; and a first contact portion that is a partial region of the transistor region, provided between an end portion of a long portion of the first dummy trench portion and an end portion of the semiconductor substrate, and electrically connects the emitter electrode and a semiconductor region with a first conductivity type provided in the transistor region.

Provided is a semiconductor device including a gate trench portion and a first trench portion adjacent to the gate trench portion. The device may include a first conductivity type drift region provided in a semiconductor substrate, a second conductivity type base region provided above the drift region, a first conductivity type emitter region provided above the base region and having a doping concentration higher than that of the drift region, and a second conductivity type contact region provided above the base region and having a doping concentration higher than that of the base region. The contact region includes a first contact portion provided on a front surface of the substrate, and a second contact portion having a doping concentration different from that of the first contact portion and provided alternately with the first contact portion in a trench extending direction on a side wall of the first trench portion.