US 12,089,503 B2
Ferromagnetic free layer, preparation method and application thereof
Yufeng Tian, Jinan (CN); Shishen Yan, Jinan (CN); Yanxue Chen, Jinan (CN); Lihui Bai, Jinan (CN); and Qikun Huang, Jinan (CN)
Assigned to Shandong University, Jinan (CN)
Filed by SHANDONG UNIVERSITY, Jinan (CN)
Filed on Mar. 15, 2022, as Appl. No. 17/694,960.
Claims priority of application No. 202111312221.9 (CN), filed on Nov. 8, 2021.
Prior Publication US 2023/0145391 A1, May 11, 2023
Int. Cl. G11C 11/10 (2006.01); G11C 11/16 (2006.01); H10B 61/00 (2023.01); H10N 50/10 (2023.01); H10N 50/85 (2023.01); H10N 52/01 (2023.01); H10N 52/80 (2023.01)
CPC H10N 50/10 (2023.02) [G11C 11/161 (2013.01); H10B 61/00 (2023.02); H10N 50/85 (2023.02); H10N 52/01 (2023.02); H10N 52/80 (2023.02)] 16 Claims
OG exemplary drawing
 
1. A ferromagnetic free layer, comprising a magnetic film alloy, wherein the magnetic film alloy have a first horizontal direction y and a second horizontal direction x perpendicular to the first horizontal direction y and comprises a plurality layers of films laminated in a vertical direction z, which is perpendicular to the first horizontal direction y and the second horizontal direction x, and a thickness of each of the films decreases gradually from a first end to a second end of the magnetic film alloy in the first horizontal direction y; the films include heavy metal films and ferromagnetic metal films, the heavy metal films and the ferromagnetic metal films are disposed alternatively; thicknesses of the heavy metal films at a same cross section of the ferromagnetic free layer, which is taken parallel to x-z plane at any position of the ferromagnetic free layer, increase or decrease successively from a top layer to a bottom layer, and a thickness of each of the ferromagnetic metal films at the same cross section is the same; or, a thickness of each of the heavy metal films at the same cross section is the same, and thicknesses of the ferromagnetic metal films at the same cross section increase or decrease successively from a top layer to a bottom layer; or, the thicknesses of the heavy metal films at the same cross section increase successively from the top layer to the bottom layer, and the thicknesses of the ferromagnetic metal films at the same cross section decrease successively from the top layer to the bottom layer; or, the thicknesses of the heavy metal films at the same cross section decrease successively from the top layer to the bottom layer, and the thicknesses of the ferromagnetic metal films at the same cross section increase successively from the top layer to the bottom layer,
wherein each of the films is formed through obliquely sputtering for predetermined sputtering times by a magnetron sputtering apparatus arranged at a predetermined oblique angle.