Three dimensional semiconductor memory devices

A three-dimensional semiconductor memory device, comprising:

• a substrate;
• a first conductive line extending in a first direction parallel to an upper surface of the substrate;
• a second conductive line extending in a second direction perpendicular to the upper surface of the substrate and intersecting the first conductive line;
• and
• a plurality of memory cells between the first conductive line and the second conductive line,
• wherein each of the plurality of memory cells includes a first variable resistance pattern and a second variable resistance pattern arranged in a third direction crossing the first direction and the second direction and parallel to the upper surface of the substrate, and
• wherein each of the first and second variable resistance patterns includes a sidewall portion adjacent to a sidewall of the first conductive line and a plurality of horizontal portions extending in the third direction from opposite ends of the sidewall portion.

A three-dimensional semiconductor memory device, comprising:

• a substrate;
• a plurality of stack structures and a plurality of buried insulating patterns alternatively arranged on the substrate in a first direction parallel to an upper surface of the substrate, each of the plurality of stack structures including a plurality of memory cells and a plurality of insulation layers alternately stacked on each other in a second direction perpendicular to the upper surface of the substrate;
• a plurality of first conductive lines extending in the first direction, at first sides of the plurality of memory cells and stacked in the second direction;
• and
• a plurality of second conductive lines between respective ones of the plurality of buried insulating patterns, at second sides of the plurality of memory cells opposite to the first sides of the plurality of memory cells,
• wherein each of the plurality of memory cells includes a plurality of variable resistance patterns and a plurality of electrodes between respective ones of the plurality of variable resistance patterns, and
• wherein the plurality of electrodes has different resistivities.