Phase change memory cell with self-aligned vertical heater and low resistivity interface

摘要

A low resistivity interface material is provided between a self-aligned vertical heater element and a contact region of a selection device. A phase change chalcogenide material is deposited directly on the vertical heater element. In an embodiment, the vertical heater element in L-shaped, having a curved vertical wall along the wordline direction and a horizontal base. In an embodiment, the low resistivity interface material is deposited into a trench with a negative profile using a PVD technique. An upper surface of the low resistivity interface material may have a tapered bird-beak extension.

主权项

1. A phase change memory cell comprising:
a first selection device and a second selection device respectively associated with a first phase change memory cell and a second phase change memory cell, the first and the second selection devices disposed along a wordline direction; a contact region on said selection devices; an interface layer in direct contact with said contact region; an L-shaped vertical heater element in direct contact with said interface layer, wherein said L-shaped vertical heater element includes a curved vertical wall and a horizontal base, wherein the vertical wall and the horizontal base of the L-shaped vertical heater element respectively have a height and a length that perpendicularly extend, and wherein said curved vertical wall of said L-shaped vertical heater element has a width extending perpendicular to a direction of the length of horizontal base and extending along said wordline direction; and a phase change material in direct contact with said vertical heater element, wherein the first and the second selection devices are separated along the wordline direction by a trench isolation that extends into and terminates within a wordline under the first and the second selection devices.