Abstract: The semiconductor device includes a first semiconductor region of a first conductivity type partially extending to a top face of a semiconductor substrate; a second semiconductor region of a second conductivity type formed on the first semiconductor region; a third semiconductor region of the first conductivity type formed on the second semiconductor region; a fourth semiconductor region of the second conductivity type formed on the second semiconductor region and adjacent to the third semiconductor region; a trench penetrating through the second semiconductor region and the third semiconductor region; a gate insulating film formed on an inner wall of the trench; and a gate electrode formed on the gate insulating film within the trench.

Abstract: After forming a first semiconductor region of a first conductivity type in a semiconductor substrate, a trench reaching a given portion of the first semiconductor region is formed in the semiconductor substrate. Then, after forming a gate insulating film on an inner wall of the trench, a second semiconductor region of a second conductivity type is formed on the first semiconductor region in the semiconductor substrate, and thereafter, a third semiconductor region of the first conductivity type is formed on the second semiconductor region in the semiconductor substrate. Also, a gate electrode of the first conductivity type is formed on the gate insulating film within the trench. The gate electrode is formed on the gate insulating film so as to extend over the second semiconductor region, a portion of the first semiconductor region disposed below the second semiconductor region and a portion of the third semiconductor region disposed on the second semiconductor region.

Abstract: A first region functioning as a transistor includes a drain region, a body region formed over the drain region, a source region formed over the body region and a trench formed through the body region and having a gate electrode buried therein. A source region is formed over the body region extending in a second region. The source region forming an upper edge of the trench is rounded.

Abstract: A semiconductor device includes: a semiconductor substrate; a first semiconductor region formed in the reverse surface region of the semiconductor substrate and including a first conductivity type impurity; a second semiconductor region formed on the first semiconductor region in the semiconductor substrate and including a second conductivity type impurity; a third semiconductor region formed on the second semiconductor region in the semiconductor substrate and including a first conductivity type impurity; a trench passing through the second and third semiconductor regions and reaching the first semiconductor region; and a gate insulating film formed along the wall face of the trench; a gate electrode formed on the gate insulating film in the trench. Further, a pocket region including a second conductivity type impurity of which peak concentration is higher than that of the second semiconductor region is formed by a side of the trench between the second semiconductor region and the third semiconductor region.

Abstract: A source region is formed by performing ion implantation plural times to diffuse an impurity from the upper surface of a semiconductor region toward a region far dawn therefrom and to increase impurity concentration in the vicinity of the upper surface of the semiconductor region, whereby the source region and a gate electrode are overlapped with each other surely. Thus, offset between the gate and the source is prevented and an excellent ohmic contact is formed between a source electrode and the source region.

Abstract: A first region 11 functioning as a transistor includes a drain region 111, a body region 112 formed over the drain region 111, a source region 113A formed over the body region 112 and a trench formed through the body region 112 and having a gate electrode 120 buried therein. A source region 113B is formed over the body region 112 extending in a second region 12.