Method for improving aeolotropism magnetic resistance permalloy film performance

[0012] DETAILED DESCRIPTION: Preparation of anisotropic permalloy Ni in a magnetron sputtering apparatus 81 Fe 19 film. First, the glass substrate is ultrasonically cleaned with organic chemical solvents and deionized water, and then mounted on the sample base of the sputtering chamber. The substrate was cooled with circulating deionized water, a magnetic field of 250 Oe was applied parallel to the direction of the substrate, and the substrate was always rotated at a rate of 18 revolutions/min, and the sputtering deposition rate was 0.17 nm/min. Sputtering chamber background vacuum 4×10 -5 Pa, pass 99.99% purity argon into the coating chamber for 0.5 hours before sputtering, and maintain the pressure at 0.3 Pa. During sputtering, 99.99% pure high-purity argon gas pressure is 0.4Pa, followed by deposition of 6nm thickness Ta/50.0nm thickness Ni y Fe 100-y. Through the 50.0nmNi y Fe 100-y Chemical analysis found the corresponding Ni when the film composition meets 81Ni:19Fe and the film impurity content is less than 0.1% x Fe 100-x Alloy target. Use this selected permalloy target to deposit Ni 81 Fe 19 film. Buffer layer (Ni 81 Fe 19 ) 64 Cr 36 By Ni 81 Fe 19 The target and Cr target are prepared by co-sputtering method. From figure 1 (a)Ta(z)/Ni 81 Fe 19 (20nm)/Ta(9nm) in Ni 81 Fe 19 (20nm) The AMR value of the thin film varies with the thickness of Ta. It can be seen that with the increase of z, the AMR value first increases and then decreases. When z=5.4nm, the AMR value of the film is the largest, which is 2.23±0.08 %. figure 1 (b) is (Ni 81 Fe 19 ) 64 Cr 36 (z)/Ni 81 Fe 19 (20nm)/Ta(9nm) in Ni 81 Fe 19 (20nm) film AMR value varies with (Ni 81 Fe 19 ) 64 Cr 36 The thickness curve shows that with the increase of z, the AMR value first increases and then decreases. When z=5.5nm, the AMR value of the film is the largest, 2.53%. versus figure 1 (a) Compared to figure 1 (a) Ni with 5.4nm Ta as the buffer layer 81 Fe 19 (20nm) The AMR value of the film is increased by 13%. It can be seen that (Ni 81 Fe 19 ) 64Cr 36 The buffer layer can improve Ni more than the Ta buffer layer 81 Fe 19 (20nm) Thin film AMR value. figure 2 Ta(6nm)/Ni 81 Fe 19 (20nm)/Al 2 O 3 The AMR value in (z)/Ta(6nm) film varies with Al 2 O 3 The curve of thickness z change. It can be seen that with the increase of z, the AMR value first increases and then decreases. When z=1.5nm, the AMR value of the film is the largest, which is 2.20%. Than without Al inserted 2 O 3 Time Ni 81 Fe 19 (20nm) The AMR value of the thin film is increased by about 10%. It can be seen that the deposition of Al 2 O 3 Nano oxide layer can improve Ni 81 Fe 19 (20nm) Thin film AMR value. Combining the advantages of the two, we prepared the structure as (Ni 81 Fe 19 ) 64 Cr 36 /Ni 81 Fe 19 /Al 2 O 3 /Ta samples. In film (Ni 81 Fe 19 ) 64 Cr 36 (5.5nm)/Ni 81 Fe 19 (20nm)/Al 2 O 3 The AMR value in (1.5nm)/Ta(9nm) reaches 2.75%, which is comparable to the traditional structure of the film Ta(5nm)/Ni 81 Fe 19 Compared with (20nm)/Ta(9nm) (its AMR value is 2.2%), it is increased by 25%.