Frequency response of common lead and shield type magnetic tunneling junction head

Author

Shimazawa, K. ; Sun, J.J. ; Kasahara, N. ; Sato, K. ; Kagami, T. ; Saruki, S. ; Redon, O. ; Fujita, Y. ; Umehara, T. ; Syoji, J. ; Araki, S. ; Matsuzaki, M.

Author_Institution

Data Storage Technol. Center, TDK Corp., Nagano, Japan

Volume

37

Issue

4

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

1684

Lastpage

1686

Abstract

In this work, the frequency response in magnetic tunnel junction (MTJ) heads was studied. Both stray capacitance and junction resistance, forming a low-pass-filter, have to be reduced to improve the cutoff frequency in MTJ heads. By employing an Ar gas cluster ion beam (GCIB) process, junctions grown on the magnetic shield show a resistance area product as low as 3.6 Ωμm² and tunneling magneto-resistance over 14%. The dominant capacitance in common lead and shield MTJ heads was found mainly resulting from the shield-to-shield spacing, whose capacitance can be reduced by using an SiO₂ gap layer instead of Al₂O₃ layer and thus leading to an improved frequency response. Simple analysis indicates that a read amplifier design with low impedance could be helpful to realize a high data transfer rate, and a rate of around 800 Mbps for 100 Gbits/in² recording system can be thus expected

Keywords

frequency response; magnetic heads; magnetic shielding; spin valves; tunnelling; cutoff frequency; frequency response; high data transfer rate; junction resistance; low impedance; low-pass-filter; read amplifier design; shield type magnetic tunneling junction head; shield-to-shield spacing; stray capacitance; tunneling magneto-resistance; Capacitance; Frequency response; Impedance; Ion beams; Magnetic heads; Magnetic recording; Magnetic shielding; Magnetic tunneling; Sun; Voltage;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.950937

Filename

950937