Abstract: A semiconductor device comprises: an n-type semiconductor substrate; a p-type anode region formed in the semiconductor substrate on its front surface side; an n-type field stop region formed in the semiconductor substrate on its rear surface side with protons as a donor; and an n-type cathode region formed in the semiconductor substrate to be closer to its rear surface than the field stop region is, wherein a concentration distribution of the donor in the field stop region in its depth direction has a first peak, and a second peak that is closer to the rear surface of the semiconductor substrate than the first peak is, and has a concentration lower than that of the first peak, and a carrier lifetime in at least a partial region between the anode region and the cathode region is longer than carrier lifetimes in the anode region.

Abstract: In some aspects of the invention, an n-type field-stop layer can have a total impurity of such an extent that a depletion layer spreading in response to an application of a rated voltage stops inside the n-type field-stop layer together with the total impurity of an n? type drift layer. Also, the n-type field-stop layer can have a concentration gradient such that the impurity concentration of the n-type field-stop layer decreases from a p+ type collector layer toward a p-type base layer, and the diffusion depth is 20 ?m or more. Furthermore, an n+ type buffer layer of which the peak impurity concentration can be higher than that of the n-type field-stop layer at 6×1015 cm?3 or more, and one-tenth or less of the peak impurity concentration of the p+ type collector layer, can be included between the n-type field-stop layer and p+ type collector layer.

Abstract: In some aspects of the invention, an n-type field-stop layer can have a total impurity of such an extent that a depletion layer spreading in response to an application of a rated voltage stops inside the n-type field-stop layer together with the total impurity of an n? type drift layer. Also, the n-type field-stop layer can have a concentration gradient such that the impurity concentration of the n-type field-stop layer decreases from a p+ type collector layer toward a p-type base layer, and the diffusion depth is 20?m or more. Furthermore, an n+ type buffer layer of which the peak impurity concentration can be higher than that of the n-type field-stop layer at 6×1015 cm?3 or more, and one-tenth or less of the peak impurity concentration of the p+ type collector layer, can be included between the n-type field-stop layer and p+ type collector layer.

Abstract: A trench gate type MOS gate structure is provided in an active region on a substrate front surface side, and a floating p-type region is provided in a mesa region between trenches. A groove is provided distanced from the trench in a surface layer on the substrate front surface side of the floating p-type region. A second gate electrode is provided across an insulation layer in the interior portion of the groove. The second gate electrode covers the surface on the substrate front surface side of the floating p-type region. Thus, the second gate electrode is embedded in a surface layer on the substrate front surface side of the floating p-type region between the floating p-type region and an interlayer dielectric, whereby the substrate front surface is flattened. Controllability of turn-on di/dt is high, mirror capacitance is low, and an element structure having an intricate pattern can be formed.

Abstract: In some aspects of the invention, an n-type field-stop layer can have a total impurity of such an extent that a depletion layer spreading in response to an application of a rated voltage stops inside the n-type field-stop layer together with the total impurity of an n? type drift layer. Also, the n-type field-stop layer can have a concentration gradient such that the impurity concentration of the n-type field-stop layer decreases from a p+ type collector layer toward a p-type base layer, and the diffusion depth is 20 ?m or more. Furthermore, an n+ type buffer layer of which the peak impurity concentration can be higher than that of the n-type field-stop layer at 6×1015 cm?3 or more, and one-tenth or less of the peak impurity concentration of the p+ type collector layer, can be included between the n-type field-stop layer and p+ type collector layer.

Abstract: A p-layer on a surface layer of one of n? drift layers is separated into a p-base-region and a floating p-region by a plurality of trenches. A first gate electrode is disposed on a side wall of the trench on the p-base-region side via a first insulation film, and a shield electrode is disposed on a side wall of the trench on the floating p-region side via a second insulation film. Between the first gate electrode conductively connected to a gate runner via a contact plug embedded in a first contact hole and the shield electrode conductively connected to an emitter electrode via a contact plug embedded in a second contact hole, an insulation film reaches from the front surface of the substrate to the bottom surface of the trench. Hence, the fabrication process can be shortened to provide a highly reliable semiconductor device with low switching loss.

Abstract: Provided is a semiconductor device and a method for forming the same. The device has a substrate including one and another surfaces. A first semiconductor region of a first conductivity type is formed in the substrate. A second conductivity type, second semiconductor region is provided in a first surface layer, that includes the one surface, of the substrate. A first electrode is in contact with the second semiconductor region to form a junction therebetween. A first conductivity type, third semiconductor region is provided in a second surface layer, that includes the another surface, of the substrate. The third semiconductor region has a higher impurity concentration than the first semiconductor region. A fourth semiconductor region of the second conductivity type is provided in the first semiconductor region at a location deeper than the third semiconductor region from the another surface. A second electrode is in contact with the third semiconductor region.

Abstract: A semiconductor device has mesa form first and second p-type base regions and a floating p-type region provided in a surface layer of an n?-type drift layer. The first p-type base region and floating p-type region are separated by a first trench. The second p-type base region is separated from the floating p-type region by a second trench. The first and second p-type base regions are conductively connected to an emitter electrode. The floating p-type region is in a floating state electrically isolated from the emitter electrode. A first gate electrode is provided via a first gate insulating film inside the first trench. An emitter potential second gate electrode is provided via a second gate insulating film inside the second trench. Therefore, di/dt controllability when turning on the semiconductor device can be increased.

Abstract: A p-type base layer is selectively formed on a surface of an n-type drift layer; an n-type source layer is selectively formed on a surface of the p-type base layer; and a p-type contact layer is formed to be in contact with the selectively-formed n-type source layer. A p-type counter layer is formed to be in contact with the n-type source layer, so as to overlap the p-type contact layer, so as to be separated from an interface where the p-type base layer and the gate oxide film are in contact with each other, and to be shallower than the p-type base layer. Accordingly, switching destruction caused by process defects in an insulated gate semiconductor device is reduced.

Abstract: A semiconductor device includes stripe-shaped gate trench formed in one major surface of n-type drift layer, gate trench including gate polysilicon formed therein, and gate polysilicon being connected to a gate electrode; p-type base layer formed selectively in mesa region between adjacent gate trenches, p-type base layer including n-type emitter layer and connected to emitter electrode; one or more dummy trenches formed between p-type base layers adjoining to each other in the extending direction of gate trenches; and electrically conductive dummy polysilicon formed on an inner side wall of dummy trench with gate oxide film interposed between dummy polysilicon and dummy trench, dummy polysilicon being spaced apart from gate polysilicon. Dummy polysilicon may be connected to emitter electrode. The structure according to the invention facilitates providing an insulated-gate semiconductor device, the Miller capacitance of which is small, even when the voltage applied between the collector and emitter is low.

Abstract: A front surface element structure is formed on the front surface side of an n?-type semiconductor substrate. Then defects are formed throughout an n?-type semiconductor substrate to adjust a carrier lifetime. Hydrogen ions are ion-implanted from a rear surface side of the n?-type semiconductor substrate, and a hydrogen implanted region having a hydrogen concentration higher than a hydrogen concentration of a bulk substrate is formed in the surface layer of a rear surface side of the n?-type semiconductor substrate.

Abstract: A semiconductor device includes a stripe-shaped gate trench formed in one major surface of n-type drift layer, a gate trench including gate polysilicon formed therein, and a gate polysilicon connected to a gate electrode. A p-type base layer is formed selectively in mesa region between adjacent gate trenches and a p-type base layer including an n-type emitter layer and connected to emitter electrode. One or more dummy trenches are formed between p-type base layers adjoining to each other in the extending direction of gate trenches. An electrically conductive dummy polysilicon is formed on an inner side wall of dummy trench with a gate oxide film interposed between the dummy polysilicon and dummy trench. The dummy polysilicon is spaced apart from the gate polysilicon and may be connected to the emitter electrode.

Abstract: A p-type base layer is selectively formed on a surface of an n-type drift layer; an n-type source layer is selectively formed on a surface of the p-type base layer; and a p-type contact layer is formed to be in contact with the selectively-formed n-type source layer. A p-type counter layer is formed to be in contact with the n-type source layer, so as to overlap the p-type contact layer, so as to be separated from an interface where the p-type base layer and the gate oxide film are in contact with each other, and to be shallower than the p-type base layer. Accordingly, switching destruction caused by process defects in an insulated gate semiconductor device is reduced.

Abstract: A semiconductor device is disclosed in which proton implantation is performed a plurality of times to form a plurality of n-type buffer layers in an n-type drift layer at different depths from a rear surface of a substrate. The depth of the n-type buffer layer, which is provided at the deepest position from the rear surface of the substrate, from the rear surface of the substrate is more than 15 ?m. The temperature of a heat treatment which is performed in order to change a proton into a donor and to recover a crystal defect after the proton implantation is equal to or higher than 400° C. In a carrier concentration distribution of the n-type buffer layer, a width from the peak position of carrier concentration to an anode is more than a width from the peak position to a cathode.

Abstract: A semiconductor device includes a first gate electrode that is provided on a first insulating film along one side wall of a first trench and is provided in a second trench, a shield electrode that is provided on a second insulating film along the other side wall of the first trench and is provided in a third trench, a gate runner that is an extended portion of the second trench, has a portion which is provided on the first gate electrode, and is connected to the first gate electrode, and an emitter polysilicon layer that is an extended portion of the third trench, has a portion which is provided on the shield electrode, and is connected to the shield electrode. The semiconductor device has improved turn-on characteristics with a slight increase in the number of process steps, while preventing increase in costs and reduction in yield.

Abstract: A semiconductor device includes a first gate electrode that is provided on a first insulating film along one side wall of a first trench and is provided in a second trench, a shield electrode that is provided on a second insulating film along the other side wall of the first trench and is provided in a third trench, a gate runner that is an extended portion of the second trench, has a portion which is provided on the first gate electrode, and is connected to the first gate electrode, and an emitter polysilicon layer that is an extended portion of the third trench, has a portion which is provided on the shield electrode, and is connected to the shield electrode. The semiconductor device has improved turn-on characteristics with a slight increase in the number of process steps, while preventing increase in costs and reduction in yield.

Abstract: An insulated gate semiconductor device includes a region that is provided between trenches in which a gate electrode is filled through a gate insulating film in a surface layer of a substrate, includes a p base region and an n+ emitter region, and comes into conductive contact with an emitter electrode and a p-type floating region that is electrically insulated by an insulating film which is interposed between the p-type floating region and the emitter electrode. The p-type floating region is deeper than the trench and has a lower impurity concentration than the p base region.

Abstract: In some aspects of the invention, an n-type field-stop layer can have a total impurity of such an extent that a depletion layer spreading in response to an application of a rated voltage stops inside the n-type field-stop layer together with the total impurity of an n? type drift layer. Also, the n-type field-stop layer can have a concentration gradient such that the impurity concentration of the n-type field-stop layer decreases from a p+ type collector layer toward a p-type base layer, and the diffusion depth is 20 ?m or more. Furthermore, an n+ type buffer layer of which the peak impurity concentration can be higher than that of the n-type field-stop layer at 6×1015 cm?3 or more, and one-tenth or less of the peak impurity concentration of the p+ type collector layer, can be included between the n-type field-stop layer and p+ type collector layer.

Abstract: A p-type base layer is selectively formed on a surface of an n-type drift layer; an n-type source layer is selectively formed on a surface of the p-type base layer; and a p-type contact layer is formed to be in contact with the selectively-formed n-type source layer. A p-type counter layer is formed to be in contact with the n-type source layer, so as to overlap the p-type contact layer, so as to be separated from an interface where the p-type base layer and the gate oxide film are in contact with each other, and to be shallower than the p-type base layer. Accordingly, switching destruction caused by process defects in an insulated gate semiconductor device is reduced.

Abstract: A semiconductor device includes a stripe-shaped gate trench formed in one major surface of n-type drift layer, a gate trench including gate polysilicon formed therein, and a gate polysilicon connected to a gate electrode. A p-type base layer is formed selectively in mesa region between adjacent gate trenches and a p-type base layer including an n-type emitter layer and connected to emitter electrode. One or more dummy trenches are formed between p-type base layers adjoining to each other in the extending direction of gate trenches. An electrically conductive dummy polysilicon is formed on an inner side wall of dummy trench with a gate oxide film interposed between the dummy polysilicon and dummy trench. The dummy polysilicon is spaced apart from the gate polysilicon and may be connected to the emitter electrode.