US 12,274,185 B2
Phase change memory cell having pillar bottom electrode with improved thermal insulation
Juntao Li, Cohoes, NY (US); Ruilong Xie, Niskayuna, 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 Oct. 19, 2021, as Appl. No. 17/505,067.
Prior Publication US 2023/0122498 A1, Apr. 20, 2023
Int. Cl. G11C 16/04 (2006.01); H10B 63/00 (2023.01); H10N 70/00 (2023.01); H10N 70/20 (2023.01)
CPC H10N 70/231 (2023.02) [H10B 63/00 (2023.02); H10N 70/063 (2023.02); H10N 70/841 (2023.02); H10N 70/8613 (2023.02); H10N 70/8616 (2023.02); H10N 70/883 (2023.02)] 13 Claims
OG exemplary drawing
 
1. A phase-change memory device comprising:
a bottom electrode;
a stack of alternating electrical conductor layers stacked parallel to the bottom electrode and directly contacting a top surface of the bottom electrode, wherein the stack of alternating electrical conductor layers in turn comprises:
at least two titanium nitride (TiN) layers including a bottommost titanium nitride (TiN) layer; and
at least two tantalum nitride (TaN) layers including a topmost tantalum nitride (TaN) layer;
a metal pillar directly contacting a top surface of the topmost tantalum nitride (TaN) layer;
a phase change material element directly contacting a top surface of the metal pillar;
a thermally and electrically insulating spacer on the stack and surrounding the metal pillar under the phase change material element; and
a top electrode on the phase change material element,
wherein a lateral dimension of the metal pillar is smaller than that of the stack.