Fabrication and electric properties of lapped type of TMR heads for ∼50 Gb/in2 and beyond

Satoru Araki, Kazuki Sato, Takeo Kagami, Syunji Saruki, Takumi Uesugi, Noriaki Kasahara, Tetsuya Kuwashima, Naoki Ohta, Jijun Sun, Kentaro Nagai, Shuxiang Li, Nozomu Hachisuka, Hitoshi Hatate, Tsuneo Kagotani, Norio Takahashi, Kunihiro Ueda, Mikio Matsuzaki

Research output: Contribution to journalArticlepeer-review

38 Citations (Scopus)


Tunnel giant magnetoresistance (TMR) heads at ∼50 Gb/in2 have been fabricated using improved lapping process. Together with writer of 2.0 T pole materials, recording performance has been demonstrated at magnetic write width of 0.28 μm and magnetic read width of 0.18 μm. The resistance area product of final wafer data is around 5 Ω · μm2, with lead and contact resistance included, resulting in a final head resistance of around 200 Ω. The output voltage achieved for 1 mA bias current is 42 mV/μm, and the isolated pulses are stable. With a discrete preamplifier, the track density as measured by "747 curve" is 94 kTPI at a bit-error rate of 10-4 and the linear density is 508 kBPI, achieving an areal density of 48 Gb/in2. The noise analysis reveals that the noises come mainly from media and shot noise.

Original languageEnglish
Pages (from-to)72-77
Number of pages6
JournalIEEE Transactions on Magnetics
Issue number1 I
Publication statusPublished - 2002 Jan
Externally publishedYes


  • CPP geometry
  • Electric properties
  • Magnetic tunnel junction
  • Shot noise
  • TMR head
  • Tunnel GMR

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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