Abstract: A semiconductor device includes a first conductivity type well region formed by counter doping; a transistor having source and drain regions having a second conductivity type, at least one of the regions being arranged in the well region; a LOCOS region arranged around the at least one region in the well region; and a channel stop region having the first conductivity type arranged under the LOCOS region. The at least one region is arranged at a distance from a tip of a bird's beak of the LOCOS in a direction parallel to a channel width of the transistor. The channel stop region is arranged at a distance from the tip of the bird's beak at an opposite side to the at least one region.

Abstract: According to one embodiment, a servo pattern writing method includes: moving a head from a first one of innermost and outermost circumferences of a medium to the remainder other than the first one while controlling a position of the head in accordance with a temporary pattern preliminarily written on the medium; calculating a junction between a servo pattern to be written from the innermost circumference and a servo pattern to be written from the outermost circumference based on a movement distance of the head; first writing the servo pattern from a second one of the innermost and outermost circumferences to the junction, while controlling the position of the head in accordance with the temporary pattern; and second writing the servo pattern from the remainder other than the second one to the junction, while controlling the position of the head in accordance with the temporary pattern.