Dual Free Layer Reader for Future Recording Head

HDD areal density growth poses significant challenges on head and media and HDI developments. In this paper, we review a novel reader design - dual free layer (DFL) to address current limitations from spin-valve based single free layer (SFL) reader head. DFL reader heads with narrower RG down to 14nm and trackwidth down to 20nm have been successfully fabricated with good stability. Magnetic recording test shows over 4% linear resolution improvement and up to 0.1 order bit-error-rate reduction over SFL. This result indicates DFL reader designs are robust and attractive candidates for novel reader suitable for sustaining HDD areal density growth beyond 2Tb/in
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