The invention relates to a manufacture method of a storage device. The manufacture method comprises the steps of providing a substrate, wherein the substrate comprises a storage unit area and a
peripheral area; forming a plurality of first grid electrodes in the storage unit area and forming at least one second grid
electrode in the
peripheral area; forming a sacrifice layer on the substrate; forming a first stop layer on the sacrifice layer in the storage unit area; carrying out the
etching process by adopting the first stop layer as a
mask; sequentially forming a second stop layer on the substrate; depositing a
dielectric material on the second stop layer; carrying out the flattening process for the
dielectric material by adopting the first stop layer and the second stop layer in the storage unit area as a
grinding stop layer; removing the first stop layer and the second stop layer in the storage unit area; removing the sacrifice layer in the storage unit area so as to forming a plurality of first contact openings among the first grid electrodes after the first stop layer and the second stop layer are removed. The stop
layers in different thicknesses are formed in the storage unit area and the
peripheral area, so that a landing area contacting a plug is not compressed while the size of the storage device is further reduced.