An integrated circuit memory is based on isolation device free memory cells. The flap is movable, with respect to the wall, between a first position, in which it cooperates with a second portion of the tube, extending between the two consecutive sections, to control the volume, between the two consecutive sections, of the package being formed, and a second position, in which it is detached from the second portion. Also, preferably, it is arranged that power source noise generated in the second external power source cannot be transmitted to the phase coincidence detection unit by utilizing the first power source for the phase coincidence detection unit in the phase comparison circuit of the DLL circuit.