Side-shielded TGMR reader with track width reduction scheme

As the recording density of the hard disk increases, the smaller reader track width is required. The tunneling GMR reader which has been used in the hard disk drive has the potential for lTb/in2 due to its large MR ratio. To maintain the SNR and match the impedance of the preamplifier, the low RA less than 0.5 Omegamum² is required. However, the low RA less than 1 Omegamum² is difficult to achieve due to both the thickness and barrier height limitation. On the other hand, as the track width reduces, the side reading effect will increase the magnetic track width. In this paper, a track width reduction scheme is presented in order to reduce the resistance.