A semiconductor device includes a transistor that has: a drift region of a first conductivity type in a semiconductor substrate having a first main surface; a body region of a second conductivity type between the drift region and the first main surface; a plurality of trenches in the first main surface and patterning the semiconductor substrate into a plurality of mesas including a first mesa and a plurality of dummy mesas, the plurality of trenches including an active trench and a plurality of dummy trenches arranged in a row; a gate electrode arranged in the active trench; and a source region of the first conductivity type in the first mesa. The first mesa is arranged adjacent to the active trench. A dummy mesa is arranged between each adjacent pair of the dummy trenches. The dummy mesas do not carry load current during an on-state of the transistor.

A semiconductor device comprises a drift region (100), a body region (110), a first doped region (111) and a second doped region (112)); a first trench penetrates the first doped region (111), the body region (110) extends into the drift region (100); an extension region (150) having an opposite conductivity type to the drift region (100) and surrounding the bottom wall of the first trench; where the first trench is filled with a first conductive structure (141) and a second conductive structure (142); a dielectric layer (130) formed between the second conductive structure (142) and the inner wall of the first trench, as well as between the first conductive structure (141) and the inner wall of the first trench; a second trench penetrating the first doped region (111) and the body region (110), and a dielectric layer (130) located between the third conductive structure (143) and the second trench (122).

A semiconductor device includes a transistor cell region, and a first termination region devoid of transistor cells. The transistor cell region includes a gate structure, a plurality of needle-shaped first field plate structures, body regions of a second conductivity type, and source regions of a first conductivity type. The first termination region surrounds the transistor cell region and includes needle-shaped second field plate structures. The needle-shaped first field plate structures are arranged in a first pattern and the needle-shaped second field plate structures are arranged in a second pattern.

In a step, acceptor ions are implanted from a back surface of a semiconductor substrate. In a step, a wet process of immersing the semiconductor substrate in a chemical solution including hydrofluoric acid is performed, to introduce hydrogen atoms into the semiconductor substrate. In a step, proton radiation is provided to the back surface of the semiconductor substrate, to introduce hydrogen atoms into the semiconductor substrate and form radiation-induced defects. In a step, an annealing process is performed on the semiconductor substrate, to form hydrogen-related donors by reaction of the hydrogen atoms and the radiation-induced defects and reduce the radiation-induced defects.

A plug electrode is subject to etch back to remain in a contact hole and expose a barrier metal on a top surface of an interlayer insulating film. The barrier metal is subject to etch back, exposing the top surface of the interlayer insulating film. Remaining element structures are formed. After lifetime is controlled by irradiation of helium or an electron beam, hydrogen annealing is performed. During the hydrogen annealing, the barrier metal is not present on the interlayer insulating film covering a gate electrode, enabling hydrogen atoms to reach a mesa part, whereby lattice defects generated in the mesa part by the irradiation of helium or an electron beam are recovered, recovering the gate threshold voltage. Thus, predetermined characteristics of a semiconductor device having a structure where a plug electrode is provided in a contact hole, via barrier metal are easily and stably obtained when lifetime control is performed.

A semiconductor device is manufactured by implanting impurity ions in one surface of a semiconductor substrate made of silicon carbide; irradiating a region of the semiconductor substrate implanted with the impurity ions with laser light of a wavelength in the ultraviolet region; and forming, on a surface of a high-concentration impurity layer formed by irradiating with the laser light, an electrode made of metal in ohmic contact with the high-concentration impurity layer. When irradiating with the laser light, a first concentration peak of the impurity ions that exceeds a solubility limit concentration of the impurity ions in silicon carbide is formed in a surface region near the one surface of the semiconductor substrate within the high-concentration impurity layer.

A method includes providing a silicon carbide substrate, wherein a gate trench extends from a main surface of the silicon carbide substrate into the silicon carbide substrate and wherein a gate dielectric is formed on at least one sidewall of the gate trench, and forming a gate electrode in the gate trench, the gate electrode including a metal structure and a semiconductor layer between the metal structure and the gate dielectric.

The invention relates to a vertically structured power transistor, such as a VD-MOS or an IGBT, having a cell comprising: two symmetrical source layers (308), preferably N+ doped, which extend from a front surface (312) of the semiconductor substrate; a well layer (307), preferably P doped, comprising an area having a higher doping concentration (307b) that extends from one source layer to the other; a source/well NP junction (J3) between the source layer and the well layer. According to the invention, a cathode formed on the front surface (312) of the semiconductor substrate has a trench portion (309) with a bottom (313) that extends into the area having a higher doping concentration (307b) of the well layer (307) to a certain depth away from the source/well NP junction (J3).

A semiconductor device includes a pair of stripe-shaped gate structures formed lengthwise in parallel in a first surface of a semiconductor body and extending into the semiconductor body, each stripe-shaped gate structure including a gate electrode and a gate dielectric separating the gate electrode from the semiconductor body. The semiconductor device further includes a plurality of field electrode structures formed in the semiconductor body between the pair of stripe-shaped gate structures, a body zone of a second conductivity type formed in the semiconductor body and extending between the pair of stripe-shaped gate structures, and a source zone of a first conductivity type opposite the second conductivity type formed in the body zone. Each field electrode structure includes a spicular or needle-shaped field electrode and a field dielectric adjacent the field electrode. Each spicular or needle-shaped field electrode has a diameter of at most 500 nm.

A semiconductor device includes a field electrode structure with a field electrode and a field dielectric surrounding the field electrode. A semiconductor body includes a transistor section surrounding the field electrode structure and including a source zone, a first drift zone section and a body zone separating the source zone and the first drift zone section. The body zone forms a first pn junction with the source zone and a second pn junction with the first drift zone section. A gate structure surrounds the field electrode structure and includes a gate electrode and a gate dielectric separating the gate electrode and the body zone. A contact structure directly adjoins the source and body zones and surrounds the field electrode structure equably with respect to the field electrode structure.