Semiconductor device for protecting electrostatic discharge and method of fabricating the same

Abstract

In a semiconductor device for protecting an electrostatic discharge and a method of fabricating the same, a gate electrode is disposed on a semiconductor substrate of first conductivity type, and a heavily doped region and a vertical lightly doped region surround the heavily doped region. The heavily doped region and vertical lightly doped region have a second conductivity type and are disposed in the semiconductor substrate on both sides of the gate electrode. The vertical lightly doped region has a lower impurity concentration and a larger depth than the heavily doped regions. A horizontal lightly doped region, which has a lower impurity concentration than the vertical lightly doped region, is further disposed in an upper side of the vertical lightly doped region. The method comprises forming a gate electrode on a semiconductor substrate of first conductivity type, forming a heavily doped region of second conductivity type in the semiconductor substrate beside the gate electrode, and forming a vertical lightly doped region of second conductivity type surrounding the heavily doped region. The vertical lightly doped region is formed to have a lower impurity concentration and a larger depth than the heavily doped region.