Semiconductor device and manufacturing method thereof

Abstract(summary):

A semiconductor device includes: a layer of a first conductivity type; a well of a second conductivity type on the layer of the first conductivity type in an active region; and a flat RESURF layer of the second conductivity type on the layer of the first conductivity type on an outer circumference of the well as a termination structure. The RESURF layer includes a low concentration layer arranged at an inner end on the well side and an outer end on the outer circumferential side, and a high concentration layer arranged between the inner end and the outer end and having a higher impurity concentration than the low concentration layer.