Tunneling magnetoresistive heads beyond 150 Gb/in(2)

• Published in: IEEE transactions on magnetics 2004-01, Vol.40 (1), p.307-312
• Main Authors: Mao, Sining, Linville, E, Nowak, J, Zhang, Zhenyong, Chen, Shawn, Karr, B, Anderson, P, Ostrowski, M, Boonstra, T, Cho, Haeseok, Heinonen, O, Kief, M, Xue, Song, Price, J, Shukh, A, Amin, N, Kolbo, P, Lu, Pu-Ling, Steiner, P
• Format: Article
• Language: English
• ISSN: 0018-9464
• DOI: 10.1109/TMAG.2003.821167

Tunneling magnetoresistive (TMR) readers capable of 150 Gb/in(2) of areal density magnetic recording for hard disk drive were demonstrated with bit-error-rate performance. The head design used is basically a bottom type stack of Ta/PtMn/CoFe/Ru/CoFe/oxide barrier/CoFe/NiFe/Ta cap with abutted hard bias stabilization. The electrical reader width is about 4 mu'' to reach a very high track density and shield-to-shield spacing is about 700 /Aring/ for high linear density. On-track bit error floor is better than 10(-5) at a linear density of 900 KBPI and the recording system noise is dominated by the media. The best areal density achieved (using -4 OTC reference level) is 143 Gb/in(2) using symmetric squeeze and 152 Gb/in(2) using asymmetric squeeze method, respectively. It was found that the TMR head has several decibels more signal-to-noise ratio gain over spin valve readers at 150 Gb/in(2) and beyond. The TMR head is also suitable for perpendicular recording application.