Vertical channel nMOSFET with an asymmetric graded lightly doped drain

A novel vertical channel nMOSFET with an asymmetric graded lightly doped drain (AGLDD) is first proposed and experimentally demonstrated. The vertical AGLDD structure is achieved by conventional ion implantation and impurity diffusion. The device fabrication is compatible with planar CMOS technology. The novel transistor shows very good immunity of short channel effects in DC characteristics.