High Moment Materials and Fabrication Processes for Shielded Perpendicular Write Head Beyond 200 Gb/in$^{2}$

Commercial hard-drive products utilizing perpendicular magnetic recording technology have recently been announced and introduced. In this paper, we review key magnetic materials characteristics and wafer process attributes in fabricating perpendicular write heads. It becomes increasingly important for write-head materials to possess not only high magnetic moment, but also optimal coercivity, remanence, anisotropy Hk, magnetostriction, and stress in order to meet head performance and reliability requirements. Advanced materials and film architectures discussed in this paper resulted in a significantly improved performance margin, including reduced pole erasure; hence enabling higher recording densities. Novel wafer-processing techniques are required for fabrication of 3-D pole features with controlled shape, and with critical dimensions of less than 150 nm. The advance in wafer process has been driven by rapidly decreasing trackwidth, as well as by the evolving head architecture from unshielded rectangular pole to shielded trapezoidal pole