US 12,207,570 B2
Phase change memory with multi-level programming
Ching-Tzu Chen, Ossining, NY (US); Juntao Li, Cohoes, NY (US); Kangguo Cheng, Schenectady, NY (US); and Carl Radens, Lagrangeville, NY (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed on Mar. 16, 2022, as Appl. No. 17/655,081.
Prior Publication US 2023/0301207 A1, Sep. 21, 2023
Int. Cl. H10N 70/20 (2023.01); H10B 63/00 (2023.01); H10B 63/10 (2023.01); H10N 70/00 (2023.01)
CPC H10N 70/231 (2023.02) [H10B 63/10 (2023.02); H10B 63/845 (2023.02); H10N 70/063 (2023.02); H10N 70/823 (2023.02); H10N 70/8822 (2023.02); H10N 70/8825 (2023.02); H10N 70/8828 (2023.02)] 16 Claims
OG exemplary drawing
 
1. A phase change memory (PCM) device comprising:
a first electrode formed on a substrate;
a phase change material stack formed on the substrate and surrounding the first electrode, the phase change material stack having a slanted side profile, and including at least two phase change material layers each separated by an insulating layer; and
a second electrode formed on and surrounding the phase change material stack,
wherein a first one of the phase change material layers has a length that is different from a length of a second one of the phase change material layers.