Patent ID: 7910905

Claim:
A memory element comprising: a substrate, first and second electrodes, each located on a same horizontal plane that is parallel to the substrate; first and second dielectric materials between the first and second electrodes; and a planar phase change material between the first and second electrodes, located on the horizontal plane and vertically disposed between and in contact with the first and second dielectric materials such that the first and second dielectric materials and the phase change material form a stack, the first electrode formed on a first sidewall of the stack and the second electrode being formed on a second sidewall of the stack, the stack having at least first, second and third portions, the first portion having a width less than the widths of the second and third portions, wherein the second portion is in contact with the first electrode and the third portion is in contact with the second electrode, wherein the first portion is between the second and third portions, wherein the second portion is between the first electrode and the first portion, and wherein the third portion is between the second electrode and the first portion, such that a programmable volume of the phase change material is not in contact with the first or second electrodes.