US 11,723,287 B2
Method of manufacturing magnetic tunnel junction (MTJ) device
Da-Jun Lin, Kaohsiung (TW); Shih-Wei Su, Tainan (TW); Bin-Siang Tsai, Changhua County (TW); and Ting-An Chien, Tainan (TW)
Assigned to UNITED MICROELECTRONICS CORP., Hsin-Chu (TW)
Filed by UNITED MICROELECTRONICS CORP., Hsin-Chu (TW)
Filed on Sep. 29, 2022, as Appl. No. 17/956,772.
Application 17/956,772 is a division of application No. 16/916,037, filed on Jun. 29, 2020, granted, now 11,495,737.
Prior Publication US 2023/0017965 A1, Jan. 19, 2023
Int. Cl. H01L 27/22 (2006.01); H01L 43/02 (2006.01); H01L 43/08 (2006.01); H01L 43/10 (2006.01); H01L 43/12 (2006.01); H10N 50/80 (2023.01); H10B 61/00 (2023.01); H10N 50/01 (2023.01); H10N 50/85 (2023.01)
CPC H10N 50/80 (2023.02) [H10B 61/00 (2023.02); H10N 50/01 (2023.02); H10N 50/85 (2023.02)] 19 Claims
OG exemplary drawing
 
1. A method of manufacturing a magnetic tunnel junction (MTJ) device, comprising:
providing a substrate;
sequentially forming a bottom electrode layer, a blanket reference layer, a blanket tunnel barrier layer, a blanket first ferromagnetic layer, a spacer layer, a blanket second ferromagnetic layer and a top electrode layer on the substrate;
patterning the top electrode layer, the blanket second ferromagnetic layer, the spacer layer, the blanket first ferromagnetic layer, the blanket tunnel barrier layer, the blanket reference layer and the bottom electrode layer to form a bottom electrode, a reference layer, a tunnel barrier layer, a free layer, which is composed by a first ferromagnetic layer, a spacer and a second ferromagnetic layer, and a top electrode on the substrate; and
performing a selective oxidation process to only oxidize the first ferromagnetic layer, the spacer and the second ferromagnetic layer, to form oxidized spacer sidewall parts of the spacer, first oxidized sidewall parts of the first ferromagnetic layer, and second oxidized sidewall parts of the second ferromagnetic layer, wherein outer sidewalls of the first oxidized sidewall parts, the oxidized spacer sidewall parts and the second oxidized sidewall parts are parallel to a height direction of the MTJ device.