A method including forming a first member having a first portion including a plurality of storage capacitors therein and a second portion surrounding the first portion; forming a second member of a concave shape having a third portion, which corresponds to a lower top surface of the concave shape, including a plurality of access transistors provided correspondingly to the plurality of storage capacitors therein and a fourth portion, which corresponds to an upper top surface of the concave shape, surrounding the third portion; stacking the first member on the second member to physically connect the second and fourth portions and have a gap between the first and third portions; cutting the first member to physically separate the first portion from the second portion; and joining the separated first portion and the third portion with filling the gap therebetween.