Abstract: In a vertical power field effect transistor, a side surface of a gate electrode is covered with a side oxide film, and a groove is formed in self-alignment with the side oxide film to extend from a surface area of a silicon substrate between a pair of adjacent gate electrodes, to reach a base region. A tungsten film is filled into the groove thus formed, and a source electrode-is formed in contact with the tungsten film within the groove.

Abstract: A sheet cutting apparatus including an air removing mechanism and a sheet overlap preventing mechanism. The air removing mechanism includes an aligning device for pushing edges of a stack of sheets, which stack is placed on a table before being cut, towards a center of the stack to align the edges of the stack, and a cover member for covering the stack on the table such that the stack can be hermetically sealed, a pushing device for pushing the stack form above, and an evacuation device for removing air from a space between the table and the cover member to hermetically seal the space. The sheet overlap preventing mechanism is provided with a first restriction device for restricting a displacement of a plurality of stacks of cut sheets, with respect to a thickness direction of each of the stacks of cut sheets, and a second restriction device for restricting a displacement of portions to be cut off from the stacks of the cut sheets, with respect to a thickness direction of each of the portions to be cut off.

Abstract: A vertical field effect transistor of the structure having a gate pad and a gate finger, includes a semiconductor substrate of a first conduction type, and a first diffusion region of a second conduction type opposite to the first conduction type, formed in a principal surface of the substrate under the gate pad and the gate finger. A second diffusion region of the second conduction type is formed in the principal surface of the substrate and electrically connected to a source electrode so as to form a protection diode between the substrate and the second diffusion region. The second diffusion region is separated from the first diffusion region.

Abstract: A ball screw integrated type linear movement guiding unit including a guide rail, a male-threaded screw shaft, a nut having a female-threaded screw hole formed therein and end caps fastened to the opposite end surface of the nut, wherein a plurality of first through holes are drilled through the nut in the axial direction for building a linear movement guiding system in cooperation with ball rolling grooves on the guide rail and the nut, a plurality of second through holes are drilled through the nut in the axial direction in parallel with the first through holes for building a ball screw system in cooperation with ball screw grooves in the screw shaft and the ball screw grooves on the screw shaft, a plurality of first curved passages are formed in each of the end caps while building the linear movement guiding system in cooperation with the first through holes, and a plurality of second curved passages are formed in each of the end caps while building the ball screw system in cooperation with the second thro

Abstract: A freshness preserving agent comprising carbon black having a specific surface area of at most 1,000 m.sup.2 /g as measured by BET method and a palladium compound supported thereon.