Magnetic printing characteristics using master disk with perpendicular magnetic anisotropy

With the increase in recording density and capacity of hard-disk drives (HDD), high speed, high precision and low cost servo writing method has become an issue in HDD industry. The magnetic printing was proposed as the ultimate solution for this issue [1-3]. There are two types of magnetic printing methods, which are ‘Bit Printing (BP)’ and ‘Edge Printing (EP)’. BP method is conducted by applying external field whose direction is vertical to the plane of both master disk (Master) and perpendicular magnetic recording (PMR) media (Slave). On the other hand, EP method is conducted by applying external field toward down track direction of both master and slave. In BP for bit length shorter than 100 nm, the SNR of perpendicular anisotropic master was higher than isotropic master. And the SNR of EP for the bit length shorter than 50 nm was demonstrated.