摘要 |
A high performance TMR sensor is fabricated by employing a free layer with a trilayer configuration represented by FeCo/CoFeB/CoB, FeCo/CoB/CoFeB, FeCo/CoFe/CoB, or FeCo/FeB/CoB may also be employed. Alternatively, CoNiFeB or CoNiFeBM formed by co-sputtering CoB with CoNiFe or CoNiFeM, respectively, where M is V, Ti, Zr, Nb, Hf, Ta, or Mo may be included in a composite free layer or as a single free layer in the case of CoNiFeBM. A 15 to 30% in improvement in TMR ratio over a conventional CoFe/NiFe free layer is achieved while maintaining low Hc and RA<3 ohm-um2. In bilayer or trilayer embodiments, magnetostriction (lambda) between -5×10-6 and 5×10-6 is achieved by combining CoB (-lambda) and one or more layers having a positive lambda.
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