Semiconductor devices and methods for manufacturing the same are disclosed. In one aspect, the method comprises forming a first shielding layer on a substrate, and forming one of source and drain regions with the first shielding layer as a mask. Then, forming a second shielding layer on the substrate, and forming the other of the source and drain regions with the second shielding layer as a mask. Then, removing a portion of the second shielding layer which is next to the other of the source and drain regions. Lastly, forming a first gate dielectric layer, a floating gate layer, and a second gate dielectric layer, and forming a gate conductor as a spacer on a sidewall of a remaining portion of the second shielding layer.