Abstract: A method of manufacturing a switching device may include: forming a plurality of trenches in an upper surface of a semiconductor substrate, the plurality of trenches extending in parallel to each other at the upper surface; forming a mask including a masking portion and an opening portion, the masking portion and the opening portion being arranged on each of the trenches alternately and repeatedly along a longitudinal direction of the trenches; and implanting p-type impurities to a bottom surface of each of the trenches through the mask so as to form a plurality of bottom p-type regions.

Abstract: A switching device includes a semiconductor substrate; first and second trenches; gate insulating layers; and gate electrodes. The semiconductor substrate includes a first semiconductor region of a first conductivity type, a body region of a second conductivity type, a second semiconductor region of the first conductivity type, first and second bottom semiconductor regions of the second conductivity type disposed in areas extending to bottom surfaces of the first and second trenches, and a connection semiconductor region of the second conductivity type extending from the first trench to reach the second trench in a depth range from a depth of a lower end of the body region to a depth of the bottom surfaces of the first and second trenches, the connection semiconductor region contacting the second semiconductor region, and being connected to the body region, and the first and second bottom semiconductor regions.

Abstract: A switching device includes a semiconductor substrate; first and second trenches; gate insulating layers; and gate electrodes. The semiconductor substrate includes a first semiconductor region of a first conductivity type, a body region of a second conductivity type, a second semiconductor region of the first conductivity type, first and second bottom semiconductor regions of the second conductivity type disposed in areas extending to bottom surfaces of the first and second trenches, and a connection semiconductor region of the second conductivity type extending from the first trench to reach the second trench in a depth range from a depth of a lower end of the body region to a depth of the bottom surfaces of the first and second trenches, the connection semiconductor region contacting the second semiconductor region, and being connected to the body region, and the first and second bottom semiconductor regions.

Abstract: A semiconductor device includes a plurality of trench gates extending in a first direction and arranged with a space between one another in a second direction which is orthogonal to the first direction. Each of the plurality of trench gates includes: a first portion opened on a front surface of the semiconductor substrate; a second portion extending from the first portion in a direction inclined relative to a depth direction of the semiconductor substrate toward a positive direction of the second direction; and a third portion extending from the first portion in a direction inclined relative to the depth direction of the semiconductor substrate toward a negative direction of the second direction.

Abstract: A method for manufacturing a substrate is provided. The method includes irradiating a single crystal substrate with a beam of laser or charged particles while moving an irradiation point of the beam with respect to the single crystal substrate so that a trajectory of the irradiation point on a surface of the single crystal substrate describes a striped pattern of straight lines. Non-crystalline regions are formed in the single crystal substrate along the trajectory. The irradiation is repeated multiple times so that directions of the striped patterns are different from each other among the multiple times of irradiation. The repetition of the irradiation changes warpage of the single crystal substrate. All of directions of the straight lines described in the multiple times of irradiation are not parallel to any of directions of crystal axes of the single crystal substrate in a plane parallel to the surface.

Abstract: A method for manufacturing a substrate is provided. The method includes irradiating a single crystal substrate with a beam of laser or charged particles while moving an irradiation point of the beam with respect to the single crystal substrate so that a trajectory of the irradiation point on a surface of the single crystal substrate describes a striped pattern of straight lines. Non-crystalline regions are formed in the single crystal substrate along the trajectory. The irradiation is repeated multiple times so that directions of the striped patterns are different from each other among the multiple times of irradiation. The repetition of the irradiation changes warpage of the single crystal substrate. All of directions of the straight lines described in the multiple times of irradiation are not parallel to any of directions of crystal axes of the single crystal substrate in a plane parallel to the surface.

Abstract: A semiconductor device includes a plurality of trench gates extending in a first direction and arranged with a space between one another in a second direction which is orthogonal to the first direction. Each of the plurality of trench gates includes: a first portion opened on a front surface of the semiconductor substrate; a second portion extending from the first portion in a direction inclined relative to a depth direction of the semiconductor substrate toward a positive direction of the second direction; and a third portion extending from the first portion in a direction inclined relative to the depth direction of the semiconductor substrate toward a negative direction of the second direction.