Author :
Ohashi, K. ; Hayashi, K. ; Nagahara, K. ; Ishihara, K. ; Fukami, E. ; Fujikata, J. ; Mori, S. ; Nakada, M. ; Mitsuzuka, T. ; Matsuda, K. ; Mori, H. ; Kamijo, A. ; Tsuge, H.
Abstract :
A tunnel magnetoresistive (TMR) head with a low resistance of about 30 Ω and effective track width of 1.4 μm was fabricated using an in situ natural oxidation (ISNO) technique. Its read-output was almost the same as that expected from test elements at the wafer level. We found no large difference in noise voltages between TMR head and GMR head when their resistance was about 30 Ω. A very low-resistivity TMR element with a resistance-area product of 14 Ω·μm 2 and a fairly high ΔR/R of 14% was also developed using ISNO. A signal-to-noise ratio consideration suggests that such low resistance is a key to TMR heads for high recording densities
Keywords :
giant magnetoresistance; hard discs; magnetic heads; magnetic recording noise; magnetoresistive devices; oxidation; tunnelling; 1.4 micron; 30 ohm; GMR head; TMR head; effective track width; in situ natural oxidation; low-resistance tunnel magnetoresistive head; noise voltages; recording densities; resistance-area product; signal-to-noise ratio consideration; test elements; wafer level; Giant magnetoresistance; Magnetic anisotropy; Magnetic heads; Magnetic separation; Oxidation; Permanent magnets; Perpendicular magnetic anisotropy; Testing; Tunneling magnetoresistance; Voltage;
