Abstract: Aspects of the invention are directed to a vertical semiconductor device including an element active portion and a voltage withstanding structure portion that has a first main electrode and a gate pad electrode on a first main surface of the element active portion, includes first parallel pn layers in a drift layer below the first main electrode, and includes second parallel pn layers below the gate pad electrode. The vertical semiconductor device includes a first conductivity type isolation region between the second parallel pn layers below the gate pad electrode and a p-type well region disposed in a surface layer of the drift layer, and by the repetition pitch of the second parallel pn layers being shorter than the repetition pitch of the first parallel pn layers, it is possible to obtain low on-state resistance, high avalanche withstand, high turn-off withstand, and high reverse recovery withstand.

Abstract: A method of manufacturing a semiconductor device includes forming a first parallel pn layer; depositing a first-conductivity-type first semiconductor layer on a surface of the first parallel pn layer in a step that further includes forming a second parallel pn layer by selectively introducing second-conductivity-type impurities into the first semiconductor layer; and forming first second-conductivity-type impurity regions in positions opposed in a depth direction to regions of the first parallel pn layer in which second-conductivity-type semiconductor regions are formed; and forming a local insulating film on a surface of the first semiconductor layer in a termination structure portion so that an end portion of the local insulating film is positioned on the first second-conductivity-type impurity region, by heating at a low temperature effective to suppress diffusion of the first second-conductivity-type impurity regions.

Abstract: A method of manufacturing a semiconductor device includes forming a first parallel pn layer; depositing a first-conductivity-type first semiconductor layer on a surface of the first parallel pn layer in a step that further includes forming a second parallel pn layer by selectively introducing second-conductivity-type impurities into the first semiconductor layer; and forming first second-conductivity-type impurity regions in positions opposed in a depth direction to regions of the first parallel pn layer in which second-conductivity-type semiconductor regions are formed; and forming a local insulating film on a surface of the first semiconductor layer in a termination structure portion so that an end portion of the local insulating film is positioned on the first second-conductivity-type impurity region, by heating at a low temperature effective to suppress diffusion of the first second-conductivity-type impurity regions.

Abstract: Aspects of the invention are directed to a vertical semiconductor device including an element active portion and a voltage withstanding structure portion has a first main electrode and a gate pad electrode on a first main surface of the element active portion, includes first parallel pn layers in a drift layer below the first main electrode, and includes second parallel pn layers below the gate pad electrode. The vertical semiconductor device includes a first conductivity type isolation region between the second parallel pn layers below the gate pad electrode and a p-type well region disposed in a surface layer of the drift layer, and by the repetition pitch of the second parallel pn layers being shorter than the repetition pitch of the first parallel pn layers, it is possible to obtain low on-state resistance, high avalanche withstand, high turn-off withstand, and high reverse recovery withstand.

Abstract: An n? drift layer is a parallel pn layer having an n-type region and a p-type region are alternately arranged in the direction parallel to the main surface so as to come into contact with each other, and have a width in a direction parallel to the main surface of the substrate which is less than a length in a direction perpendicular to the main surface of the substrate. A second-main-surface-side lower end portion of the p-type region has a structure in which a high-concentration lower end portion and a low-concentration lower end portion of a p-type low-concentration region are repeated at a predetermined pitch in the direction parallel to the main surface of the substrate. It is possible to provide a super junction MOS semiconductor device which can improve a trade-off relationship between turn-off loss and turn-off dv/dt and improve avalanche resistance.