A semiconductor device includes a gate trench in a semiconductor substrate, a source trench in the semiconductor substrate, the source trench having a first portion and a second portion under the first portion, where the first portion of the source trench is wider than the gate trench, and extends to a depth of the gate trench. The semiconductor device also includes a gate electrode and a gate trench dielectric liner in the gate trench, and a conductive filler and a source trench dielectric liner in the source trench. The semiconductor device further includes a source region between the gate trench and the source trench, a base region between the gate trench and the source trench, and a source contact coupled to the source region and the base region.

The present invention discloses a power Metal Oxide Semiconductor (MOS) transistor, wherein a second U-shaped trench is formed below a first U-shaped trench, so that a field oxidation stress transition region can be extended, so as to greatly reduce current leakage caused by the field oxidation stress and improve the reliability of the device; and a charge compensation region is provided in a drift region at the bottom of the second U-shaped trench, and a super-junction structure is formed between the charge compensation region and the drift region to improve the breakdown voltage of the power device. According to the present invention, the second U-shaped trench and the charge compensation region are formed by a self-aligning process, so that the technical process is simple, reliable and easy to control, and can reduce the manufacturing cost of the power MOS transistor and improve its yield.

A semiconductor device includes a drift structure formed in a semiconductor body. The drift structure forms a first pn junction with a body zone of a transistor cell. A gate structure extends from a first surface of the semiconductor body into the drift structure. A heat sink structure extends from the first surface into the drift structure. A thermal conductivity of the heat sink structure is greater than a thermal conductivity of the gate structure and/or a thermal capacity of the heat sink structure is greater than a thermal capacity of the gate structure.

A semiconductor device according to the present invention includes a first conductive-type semiconductor layer, a second conductive-type base region that is arranged in the front surface portion of the semiconductor layer, a plurality of trenches that extend from a front surface of the semiconductor layer beyond a bottom portion of the base region with an active region being defined therebetween, a plurality of first conductive-type emitter regions that are arranged in the active region, each connecting the trenches adjacent to each other, a gate electrode that is embedded in the trench, an embedding insulating film that is embedded in the trench on the gate electrode and that has an upper surface in the same height position as the front surface of the semiconductor layer or in a height position lower than the front surface and an emitter electrode that covers the active region and the embedding insulating film and that is electrically connected to the base region and the emitter region.

A semiconductor device according to the present invention includes a first conductive-type semiconductor layer, a second conductive-type base region that is arranged in the front surface portion of the semiconductor layer, a plurality of trenches that extend from a front surface of the semiconductor layer beyond a bottom portion of the base region with an active region being defined therebetween, a plurality of first conductive-type emitter regions that are arranged in the active region, each connecting the trenches adjacent to each other, a gate electrode that is embedded in the trench, an embedding insulating film that is embedded in the trench on the gate electrode and that has an upper surface in the same height position as the front surface of the semiconductor layer or in a height position lower than the front surface and an emitter electrode that covers the active region and the embedding insulating film and that is electrically connected to the base region and the emitter region.

A semiconductor device includes a semiconductor substrate having an outer rim, a plurality of switchable cells defining an active area, and an edge termination region arranged between the switchable cells and the outer rim. Each of the switchable cells includes a gate electrode structure. The semiconductor device further includes a gate metallization in contact with the gate electrode structure. The active area includes at least a first switchable region having a first specific transconductance and at least a second switchable region having a second specific transconductance which is different from the first specific transconductance. The second switchable region is arranged between the gate metallization and the first switchable region. A ratio of the area of the second switchable region to the total area of the switchable regions is in a range from 5% to 50%.

A method for manufacturing a semiconductor device having an SiC-IGBT and an SiC-MOSFET in a single semiconductor chip, including forming a second conductive-type SiC base layer on a substrate, and selectively implanting first and second conductive-type impurities into surfaces of the substrate and base layer to form a collector region, a channel region in a surficial portion of the SiC base layer, and an emitter region in a surficial portion of the channel region, the emitter region serving also as a source region of the SiC-MOSFET.

A semiconductor device is provide that includes: a semiconductor body having a first surface, an inner region, and an edge region; a pn junction between a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type, the pn-junction extending in a lateral direction of the semiconductor body in the inner region; a recess extending from the first surface in the edge region into the semiconductor body, the recess comprising at least one sidewall; a dielectric filling the recess. In the dielectric, a dielectric number, in the lateral direction, decreases as a distance from the first sidewall increases.

Reduction of power consumption of a semiconductor device is aimed. The semiconductor device includes a cell region where a vertical power MOSFET is formed and an intermediate region surrounding the cell region. In each of the cell region and the intermediate region, a plurality of p-type column regions and a plurality of n-type column regions are alternately formed. The n-type column region arranged in the cell region has a defect region formed therein, whereas the n-type column region arranged in the intermediate region does not have the defect region. A defect density in the n-type column region arranged in the cell region is larger than that in the n-type column region arranged in the intermediate region.

By using a single trench mask, first and second trenches are formed that extend from a main surface into a semiconductor layer. A foundation is formed that includes first regions in and/or directly adjoining the first trenches. A superstructure is formed in alignment with the foundation by using position information directly obtained from structures formed in the first and/or the second trenches.