US Patent 11038106 Phase change memory cell with a metal layer

A method may include filling a via opening with a spacer, the via opening formed in a dielectric layer, forming a trench within the spacer, filling the trench with a metal layer, recessing the spacer to form an opening and expose an upper portion of the metal layer, wherein the exposed portion of the metal layer is formed into a cone shaped tip, conformally depositing a liner along a bottom and a sidewall of the opening and the exposed portion of the metal layer, depositing a second dielectric layer along the bottom of the opening on top of the liner, recessing the liner to form a channel and partially exposing a sidewall of the second dielectric layer and a sidewall of the metal layer, depositing a third dielectric layer in the channel, and depositing a phase change memory layer within the opening.