Patent ID: 7422926

Claim:
A process for manufacturing phase change memory cells, comprising: forming a heater element in a semiconductor wafer and a storage region of a phase change material on and in contact with said heater element; wherein said step of forming said heater element and said phase change storage region comprises: forming a heater structure and a phase change layer on and in contact with said heater structure; and defining said phase change layer and said heater structure by subsequent self-aligned etch steps in which the phase change layer is etched into an etched shape and the heater structure is defined, after the phase change layer is etched, based on the etched shape of the phase change layer, wherein said step of forming said heater element and said phase change storage region comprises: forming a dielectric layer on said wafer; forming at least a trench in said dielectric layer, said trench being elongated according to a first direction; and forming said heater structure within said trench.