US 12,484,452 B2
Method of fabricating magnetic tunneling junction device
Shun-Yu Huang, Kaohsiung (TW); Yi-Wei Tseng, New Taipei (TW); Chih-Wei Kuo, Tainan (TW); Yi-Xiang Chen, Tainan (TW); Hsuan-Hsu Chen, Tainan (TW); and Chun-Lung Chen, Tainan (TW)
Assigned to United Microelectronics Corp., Hsinchu (TW)
Filed by United Microelectronics Corp., Hsinchu (TW)
Filed on Jul. 27, 2022, as Appl. No. 17/874,327.
Claims priority of application No. 111125330 (TW), filed on Jul. 6, 2022.
Prior Publication US 2024/0016062 A1, Jan. 11, 2024
Int. Cl. H10N 50/01 (2023.01); H10B 61/00 (2023.01); H10N 50/10 (2023.01); H10N 50/80 (2023.01); G11C 11/16 (2006.01)
CPC H10N 50/01 (2023.02) [H10B 61/00 (2023.02); H10B 61/22 (2023.02); H10N 50/10 (2023.02); H10N 50/80 (2023.02); G11C 11/161 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of fabricating a magnetic tunneling junction (MTJ) device, comprising:
forming a first via in a first dielectric layer;
forming a first electrode layer on the first dielectric layer and the first via;
forming an MTJ stack layer on the first electrode layer;
forming a patterned second electrode layer on the MTJ stack layer;
using the patterned second electrode layer as a mask, performing a first ion beam etching process to etch the patterned second electrode layer and pattern the MTJ stack layer and the first electrode layer to form a second electrode, an MTJ stack structure, and a first electrode;
forming a first protective layer to cover a top surface and a sidewall of the second electrode and a sidewall of the MTJ stack structure; and
using the first protective layer as a mask, performing a second ion beam etching process to remove at least a portion of the MTJ stack structure and at least a portion of the first electrode,
wherein during the second ion beam etching process, a lower portion of the first electrode and a lower portion of the MTJ stack structure are trimmed to a greater extent than an upper portion of the first electrode and an upper portion of the MTJ stack structure.