Bit patterned media optimization at 1 Tdot/in{sup 2} by post-annealing

Journal Article · Sun Sep 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4896667· OSTI ID:22305713

Hellwig, Olav; Marinero, Ernesto E.; Kercher, Dan; Hennen, Tyler; McCallum, Andrew; Dobisz, Elizabeth; Wu, Tsai-Wei; Lille, Jeff; Hirano, Toshiki; Ruiz, Ricardo; Grobis, Michael K.; Weller, Dieter; Albrecht, Thomas R. ^[1]

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1. San Jose Research Center, HGST—A Western Digital Company, 3403 Yerba Buena Rd., San Jose, California 95135 (United States)

We report on the fabrication of 1 Tdot/in{sup 2} bit patterned media with high coercivity (H{sub C}) and narrow intrinsic switching field distribution (iSFD) based on nanoimprint from a master pattern formed by e-beam guided block copolymer assembly onto a carbon hard mask and subsequent pattern transfer via etching into a thin CoCrPt perpendicular anisotropy recording layer. We demonstrate that an additional vacuum annealing step after pattern transfer into the CoCrPt layer and after Carbon hard mask removal not only yields recovery from undesired damage of the island edges, but actually transforms the islands into a magnetically more favorable compositional phase with higher H{sub C}, lower iSFD/H{sub C}, and three-fold increased thermal stability. Energy filtered transmission electron microscopy analysis reveals that the diffusion of Cr from the island cores to the periphery of the islands during post-annealing is responsible for the transformation of the magnetic bits into a more stable state.

• OSTI ID: 22305713
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
ANNEALING
CARBON
CHROMIUM ALLOYS
COBALT ALLOYS
COERCIVE FORCE
COPOLYMERS
DIFFUSION
DISTRIBUTION
ELECTRON BEAMS
ETCHING
FABRICATION
FILTERS
LAYERS
OPTIMIZATION
PLATINUM COMPOUNDS
STABILITY
TRANSFORMATIONS
TRANSMISSION ELECTRON MICROSCOPY