Evaluation of front flux guide-type magnetic tunnel junction heads

Magnetic tunnel junction (MTJ) heads have been successfully fabricated usin g the free layer as flux guide to prevent electrical short during the defin ition of the air bearing surface (ABS). For a 6 Gbits/in(2) design, an outp ut as high as 5740 mu Vpp was achieved for 3 mA sense current, and the outp ut waveform was stable and noise free, Noise analysis confirmed that shot n oise is prevailing in these MTJ heads, suggesting that the junction resista nce has to be further reduced to challenge spin-valve heads in term of sign al to noise ratio. Landau-Lifshitz-Gilbert simulations showed that for 20 G bits/in(2) application, the flux guide height should not exceed 0.1 mum.