US 12,408,571 B2
Phase change memory with graded heater
Timothy Mathew Philip, Albany, NY (US); Kevin W. Brew, Niskayuna, NY (US); and Jin Ping Han, Yorktown Heights, NY (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Jun. 25, 2021, as Appl. No. 17/358,293.
Prior Publication US 2022/0416162 A1, Dec. 29, 2022
Int. Cl. H10N 70/00 (2023.01)
CPC H10N 70/8613 (2023.02) [H10N 70/021 (2023.02); H10N 70/841 (2023.02)] 19 Claims
OG exemplary drawing
 
1. A heater in a phase change memory, the heater comprising:
an outside conductive heating layer that has a higher electrical resistance than other layers of the heater;
a first middle conductive heating layer between the outside conductive heating layer and an inside conductive heating layer, the first middle conductive heating layer having a lower electrical resistance than the outside conductive heating layer and a higher electrical resistance than the inside conductive heating layer;
the inside conductive heating layer that has a lower electrical resistance than the outside conductive heating layer, wherein the outside conductive heating layer is at an outside area of the heater and the inside conductive heating layer is at an inside area of the heater; and
a second middle conductive heating layer between the first middle conductive heating layer and the inside conductive heating layer, the second middle conductive heating layer having a lower electrical resistance than the first middle conductive heating layer and a higher electrical resistance than the inside conductive heating layer.