A method for manufacturing a semiconductor device includes forming a plate structure over an isolation region. A drain electrode electrically connected to a drift region underlying the isolation region is formed, wherein the drain electrode is separated from a first location of the plate structure by a first distance along a central axis of an active area of the semiconductor device in a direction of a current flow between a source and a drain of the semiconductor device, the drain electrode is separated from a second location of the plate structure by a second distance along a line parallel to the central axis and within the active area. The first distance is less than the second distance.