A nonvolatile memory device includes a semiconductor substrate, a device isolation film, a tunnel insulation film, a plurality of floating gates, an inter-gate dielectric film, and a control gate pattern. Trenches are formed in the substrate that define active regions therebetween. The device isolation film is in the trenches in the substrate. The tunnel insulation film is on the active regions of the substrate. The plurality of floating gates are each on the tunnel insulation film over the active regions of the substrate. The inter-gate dielectric film extends across the floating gates and the device isolation film. The control gate pattern is on the inter-gate dielectric film and extends across the floating gates. A central region of the device isolation film in the trenches has an upper major surface that is recessed below an upper major surface of a surrounding region of the device isolation film in the trenches. An edge of the recessed central region of the device isolation film is aligned with a sidewall of an adjacent one of the floating gates.