Semiconductor devices and methods for manufacturing the same are disclosed. In one embodiment, the semiconductor device comprises a semiconductor substrate; an insulating layer located on the semiconductor substrate; a semiconductor body located on the insulating layer; a cavity formed in the semiconductor body and into the insulating layer; source/drain regions abutting opposite first side faces of the semiconductor body; gates located on opposite second side faces of the semiconductor body; a channel layer interposed between the respective second side faces and the cavity; and a super-steep-retrograded-well and a halo super-steep-retrograded-well formed in the channel layer. The super-steep-retrograded-well and the halo super-steep-retrograded-well have opposite dopant polarities.