Fabrication of multilayered Co/Pd nano-dot array with an areal density of 1 tera-dot/in2

Multilayered Co/Pd nano-dot arrays with pitches varying from 100 to 25 nm were obtained using an electron beam lithography and plasma etching process. The proximity effect in the lithography step and redeposition phenomenon in the etching step was minimized by modifying the resist development method and plasma etching parameters. For the array with a pitch of 100 nm, the ferromagnetic single domain behavior of each Co/Pd nano-dot was confirmed by magnetic force microscopy at room temperature. In addition, its magnetization, coercivity, and switching field distribution were also evaluated quantitatively using an alternating gradient magnetometer.