Semiconductor device and method of manufacturing the same

The present disclosure provides a semiconductor device, including: a substrate, wherein the substrate includes a first conductive type well region. The semiconductor device further includes a gate structure disposed over the main surface of the substrate. The semiconductor device further includes a lightly-doped drain region and a lightly-doped source region disposed at the two opposite sides of the gate structure, respectively. The semiconductor device further includes a second conductive type first doped region disposed in the lightly-doped drain region. The doping concentration of the second conductive type first doped region is less than that of the lightly-doped drain region. The semiconductor device further includes a spacer disposed at the two opposite sides of the gate structure. The semiconductor device further includes a heavily-doped source region disposed in the lightly-doped source region, wherein the heavily-doped source region has the second conductive type. The semiconductor device further inc