Methods of forming phase change memory devices having bottom electrodes

Abstract

Phase change memory devices can have bottom patterns on a substrate. Line-shaped or L-shaped bottom electrodes can be formed in contact with respective bottom patterns on a substrate and to have top surfaces defined by dimensions in x and y axes directions on the substrate. The dimension along the x-axis of the top surface of the bottom electrodes has less width than a resolution limit of a photolithography process used to fabricate the phase change memory device. Phase change patterns can be formed in contact with the top surface of the bottom electrodes to have a greater width than each of the dimensions in the x and y axes directions of the top surface of the bottom electrodes and top electrodes can be formed on the phase change patterns, wherein the line shape or the L shape represents a sectional line shape or a sectional L shape of the bottom electrodes in the x-axis direction.