The invention discloses a NOR
flash memory device and a preparation method thereof, wherein the NOR
flash memory device comprises a sequentially stacked substrate, a tunnel
oxide layer, a floating gate layer, a
dielectric layer and a control gate layer; at least one through the control gate layer and the floating gate via hole of the
dielectric layer, the floating gate via hole is located in the active area, and is used to
expose the floating gate layer to lead out the floating gate
electrode; at least one active area blocking structure, the active area blocking structure is arranged on the substrate Between the
dielectric layer and the chemical mechanical
polishing process on the floating gate layer, it is used to reduce the wear of the floating gate layer exposed by the floating gate via hole. The technical scheme of the present invention can effectively reduce the
polishing rate of the floating gate layer around it by the chemical mechanical
polishing process by adding a barrier structure in the active region, increase the thickness of the floating gate layer around it, and avoid damage caused by the floating gate layer being too thin. This leads to leakage or breakdown of the NOR
flash memory device, which improves the reliability of the NOR flash memory device.