Bit patterned media optimization at 1 Tdot/in2 by post-annealing
Bit patterned media optimization at 1 Tdot/in2 by post-annealing
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DOI：
10.1063/1.4896667
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发表时间：
2014-09-28
影响因子：
3.2
通讯作者：
Albrecht, Thomas R.
中科院分区：
文献类型：
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作者：
Hellwig, Olav;Marinero, Ernesto E.;Albrecht, Thomas R.
我们报道了基于纳米压印的1 Tdot/in（2）位图案化介质的制造，所述图案化介质具有高折射率（H-C）和窄的本征开关场分布（iSFD），所述纳米压印从通过电子束引导的嵌段共聚物组装到碳硬掩模上形成的母版图案和随后的经由蚀刻到薄的CoCrPt垂直各向异性记录层中的图案转移。我们证明，一个额外的真空退火步骤后，图案转移到CoCrPt层和碳硬掩模去除后，不仅产生恢复不希望的损伤的岛边缘，但实际上转变成一个磁性更有利的组成相，具有较高的H-C，较低的ISFD/H-C，和三倍增加的热稳定性的岛屿。能量过滤的透射电子显微镜分析表明，在后退火过程中，Cr从岛芯扩散到岛的外围是负责将磁性位转变成更稳定的状态。(C)2014 AIP Publishing LLC.
We report on the fabrication of 1 Tdot/in(2) bit patterned media with high coercivity (H-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-C, lower iSFD/H-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. (C) 2014 AIP Publishing LLC.