Phase change memory with ovonic threshold switch
View Patent ↗A phase change memory includes a memory element and a selection element. The memory element is embedded in a dielectric and includes a resistive element having at least one sublithographic dimension and a storage region in contact with the resistive element. The selection element includes a chalcogenic material embedded in a dielectric. The chalcogenic material and the storage region are part of a stack having a common etched edge.
1. A phase change memory comprising:
a U-shaped heater including a base and two spaced upstanding resistive wall elements connected to said base; and
a planar stack including a phase change material in contact with one of said wall elements and a chalcogenic selection material over said phase change material, said stack having a common edge, said phase change material being a material that changes between amorphous and crystalline phases to store information while said chalcogenide selection material is an ovonic threshold switch that does not change phase.
2. A memory according to claim 1 , including a glue region extending on one side of said wall element.
3. A memory according to claim 2 , wherein glue region includes titanium.
4. A memory according to claim 1 , wherein said wall element is laterally surrounded by oxidation-preventing regions.
5. A memory according to claim 1 , including a stack surrounded by a sealing region.
6. A memory according to claim 1 , wherein said stack comprises said storage region, a first barrier region, said selection element, and a second barrier region.
7. A memory according to claim 1 , further comprising a first connection line of conductive material extending under and in electrical contact with said resistive element and a second connection line of conductive material extending on and in electrical contact with said stack extending on said wall element.