Kuniyasu Ito

Fabrication of discrete track perpendicular media for high recording density

The feasibility of discrete track media with perpendicular anisotropy for high track density has been studied. The discrete tracks are separated physically and magnetically by grooves. The discrete track media were fabricated by using an e-beam lithography and dry etching process. In particular, the recording layer was etched using reactive ion etching with CO-NH3 mixed gas. With this process, we obtained a discrete track medium with a track pitch of 90 nm without causing damage to the magnetic recording film or degradation of its magnetic properties. To solve the flying instability issue due to the grooved surface roughness, a smooth surface like continuous layer media was obtained by using only dry processes. The surface roughness (Ra) was below 1 nm. Flying stability of a head-slider on the smooth surface of the discrete track media similar to the continuous layer media has been achieved.