A memory cell is disposed on a substrate having plurality of isolation structures that define at least a fin structure in the substrate, wherein the surface of the fin structure is higher than that of the isolation structures. The memory cell includes a gate, a charge trapping structure, a protection layer and two source/drain regions. The gate is disposed on the substrate,and straddled the fin structure. The charge trapping structure is disposed between the gate and the fin structure. The protection layer is disposed between the upper portion of the fin structure and the gate separating the charge trapping structure. The source/drain regions are disposed in the fin structure at both sides of the gate.