Methods of forming phase change memory with various grain sizes

摘要

A memory device includes a phase change element, which further includes a first phase change layer having a first grain size; and a second phase change layer over the first phase change layer. The first and the second phase change layers are depth-wise regions of the phase change element. The second phase change layer has a second average grain size different from the first average grain size.

主权项

1. A method of forming a memory device comprising:
forming a cup shaped heater element, the cup having a ring shaped top surface; forming a patterned dielectric layer over the cup shaped heater element, the patterned dielectric layer having a trench therein exposing a portion of the ring shaped top surface while leaving covered a second portion of the ring shaped top surface; forming a fine grain phase change layer in the trench and in contact with the exposed portion of the ring shaped top surface; and forming a coarse grain phase change layer on the fine grain phase change layer.