A semiconductor device with fin capacitors is disclosed. The device includes a substrate including a first region and a second region; first and second active fins at the first and second regions, respectively, of the substrate; a device isolation layer in a first trench between the first active fins; first and second gate electrodes that cross the first and second active fins, respectively; a first dielectric layer between the first active fins and the first gate electrode to extend along the first gate electrode, and a second dielectric layer between the second active fins and the second gate electrode to extend along the second gate electrode. The first dielectric layer is spaced apart from a bottom surface of the first trench by the device isolation layer between the bottom surface of the first trench and the first dielectric layer. The second dielectric layer is in direct contact with a bottom surface of a second trench between the second active fins.