Abstract: A DEMOS transistor includes a semiconductor substrate defining a field region and an active region, a gate pattern disposed on the semiconductor substrate, the gate pattern being positioned over both the active region and the field region, drift regions disposed in the active region and positioned adjacent to both sides of the gate pattern, high concentration ion regions disposed in the drift regions, and being spaced apart from the gate pattern, and a silicide blocking layer having a exposure hole exposing one of an upper surface of the gate pattern and the high concentration ion regions, the silicide blocking layer having a ring shape to at least partially surround one of the upper surface of the gate pattern and the high concentration ion regions.

Abstract: A high voltage semiconductor device includes a gate electrode structure disposed on a substrate, a source region disposed in the substrate to be adjacent to one side of the gate electrode structure, a first drift region disposed in the substrate to be adjacent to another side of the gate electrode structure, a drain region electrically connected with the first drift region, and a device isolation region disposed on one side of the drain region. Particularly, the first drift region is spaced apart from the device isolation region.

Abstract: A high voltage semiconductor device includes a gate electrode structure disposed on a substrate, a source region disposed in the substrate to be adjacent to one side of the gate electrode structure, a first drift region disposed in the substrate to be adjacent to another side of the gate electrode structure, a drain region electrically connected with the first drift region, and a device isolation region disposed on one side of the drain region. Particularly, the first drift region is spaced apart from the device isolation region.