US 12,317,752 B2
MRAM structure with multilayer encapsulation
Oscar van der Straten, Guilderland Center, NY (US); Koichi Motoyama, Clifton Park, NY (US); Joseph F. Maniscalco, Lake Katrine, NY (US); and Chih-Chao Yang, Glenmont, NY (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed on May 12, 2021, as Appl. No. 17/302,766.
Prior Publication US 2022/0367788 A1, Nov. 17, 2022
Int. Cl. H10N 50/80 (2023.01); H10B 61/00 (2023.01); H10N 50/01 (2023.01)
CPC H10N 50/80 (2023.02) [H10B 61/00 (2023.02); H10N 50/01 (2023.02)] 24 Claims
OG exemplary drawing
 
1. A semiconductor structure comprising:
a magnetic tunnel junction, the magnetic tunnel junction having a first magnetic layer and a second magnetic layer separated by a tunnel layer;
a hard mask cap above the second magnetic layer, wherein a width of the hard mask cap is less than a width of the second magnetic layer;
a first encapsulation spacer positioned along and directly contacting vertical sidewalls of the hard mask cap, wherein a top surface of the first encapsulation spacer is flush with a top surface of the hard mask cap;
a second encapsulation spacer positioned along and directly contacting vertical sidewalls of the second magnetic layer, wherein a top surface of the second encapsulation spacer is flush with the top surface of the hard mask cap;
a third encapsulation spacer positioned along vertical sidewalls of the tunnel layer, wherein a top surface of the third encapsulation spacer is flush with the top surface of the hard mask cap;
a fourth encapsulation spacer positioned along vertical sidewalls of the first magnetic layer, wherein a top surface of the fourth encapsulation spacer is flush with the top surface of the hard mask cap;
a first metal interconnect above the hard mask cap; and
a barrier layer separating upper surfaces of each of the first encapsulation spacer, second encapsulation spacer, third encapsulation spacer, and fourth encapsulation spacer from the first metal interconnect.