High-voltage semiconductor device, semiconductor device and method of forming thereof

A semiconductor device and its method of manufacture are provided. Embodiments forming an active region in a semiconductor substrate, wherein the active region is bounded by an isolation region; forming a first doped region within the active region; forming a gate electrode over the active region, wherein the gate electrode overlies a portion of the first doped region; forming at least one dielectric layer over sidewalls of the gate electrode; forming a pair of spacers on the dielectric layer; and forming a second doped region substantially within the portion of the first doped region adjacent the one of the spacers and spaced apart from the one of the spacers. The first and second doped regions may form a double diffused drain structure as in an HVMOS transistor.