US 12,219,882 B2
Memory cell with low resistance top electrode contact and methods for forming the same
Hsing-Hsiang Wang, Hsinchu (TW); Yu-Feng Yin, Hsinchu County (TW); Jiann-Horng Lin, Hsinchu (TW); and Huan-Just Lin, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company Limited, Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company Limited, Hsinchu (TW)
Filed on Apr. 14, 2021, as Appl. No. 17/230,640.
Claims priority of provisional application 63/042,585, filed on Jun. 23, 2020.
Prior Publication US 2021/0399207 A1, Dec. 23, 2021
Int. Cl. H10N 50/80 (2023.01); H10B 61/00 (2023.01); H10N 50/01 (2023.01)
CPC H10N 50/80 (2023.02) [H10B 61/22 (2023.02); H10N 50/01 (2023.02)] 20 Claims
OG exemplary drawing
 
12. A manufacturing method of a memory device, comprising:
forming a bottom electrode material layer, a magnetic tunnel junction (MTJ) material layer, and a top electrode layer;
patterning the bottom electrode material layer, the MTJ material layer, and the top electrode layer to respectively form a bottom electrode, a memory material stack that comprises a magnetic tunnel junction which includes a free layer, and a top electrode;
forming an etch stop layer and a dielectric layer over the top electrode; and
forming a conductive contact structure through the dielectric layer and the etch stop layer, wherein the conductive contact structure comprises:
a metallic fill material;
a bottom surface that is formed directly on a top surface of the free layer; and
a top surface which is formed within a same horizontal plane as a top surface of the dielectric layer, said bottom surface being a bottom surface of said metallic fill material, and said top surface of the conductive contact structure being a top surface of said metallic fill material,
wherein the conductive contact structure comprises an upper portion having a first sidewall and a lower portion having a second sidewall, and wherein a top periphery of the second sidewall is laterally offset inward relative to a bottom periphery of the first sidewall by a connecting surface segment such that a vertical cross-sectional view of the conductive contact structure has a stepped vertical cross-sectional profile in which a width of the conductive contact via structure increases stepwise along a vertical direction at the connecting surface segment.