Nonvolatile memory device and method for manufacturing same

A nonvolatile memory device comprising:

• at least one first interconnection extending in a first direction;
• at least one second interconnection disposed above the first interconnection and extending in a second direction nonparallel to the first direction;
• a memory cell disposed between the first interconnection and the second interconnection at an intersection of the first interconnection and the second interconnection and including a memory element;
• an element isolation layer disposed between the memory cells;
• and
• at least one dielectric film with a higher density than the element isolation layer being disposed on a sidewall surface of the memory cell,
• the element isolation layer including a low-k material, a dielectric constant of the element isolation layer being lower than a dielectric constant of the dielectric film, a sidewall surface and a bottom surface of the element isolation layer being covered with the continuous dielectric film.