Title :
5 Tdot/inch2 bit-patterned media fabricated by directed self-assembling polymer mask
Author :
Kamata, Yukio ; Maeda, T. ; Hieda, H. ; Yamamoto, Ryo ; Kihara, Naoya ; Kikitsu, Akira
Author_Institution :
Corp. R&D Center, Toshiba Corp., Kawasaki, Japan
fDate :
Oct. 31 2012-Nov. 2 2012
Abstract :
FePt bit-patterned media (BPM) was fabricated with a self-assembled polymer mask with 12 nm pitch (equivalent to 5 Tdot/inch2). A 3.2 nm FePt film with high c axis crystal orientation was prepared for the magnetic recording layer. Solvent vapor annealing was applied for uniform directed self-assembling of PS (polystyrene) - PDMS (polydimethylsiloxane) diblock copolymer. Pattern transfer from a polymer mask to FePt layer was achieved by employing a C hard mask. In spite of excellent magnetic characteristics of FePt layer, the fabricated FePt BPM showed small coercivity (Hc) of 6 kOe and large switching field distribution (SFD) of 21%. These results are due to the etching damage of FePt dots. Disordering of FePt L10 phase by the etching damage reduced magnetic anisotropy energy (Ku).
Keywords :
magnetic anisotropy; masks; polymers; bit patterned media; crystal orientation; diblock copolymer; etching damage; magnetic anisotropy energy; magnetic recording layer; pattern transfer; self assembled polymer mask; self assembling polymer mask; solvent vapor annealing; switching field distribution; uniform directed self assembling; Magnetic domain walls; Magnetic domains; Magnetic hysteresis; Magnetic recording; Magnetic resonance imaging; Polymers; Saturation magnetization; FePt; bit patterned media; diblock copolymer; directed self-assembly; switching field distribution;
Conference_Titel :
APMRC, 2012 Digest
Conference_Location :
Singapore
Print_ISBN :
978-1-4673-4734-1
