【作者】 周阳；

【导师】 程伟明；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2015， 硕士

【摘要】 图案化磁记录技术采用二维有序磁性纳米阵列作为记录介质,它能够突破常规连续薄膜介质中存在的超顺磁效应极限,并有可能将硬盘存储面密度提升到5Tb/in2。图案化记录技术走向实用的关键是研发出高性能的图案化磁记录介质,由于FePt具有超高的磁各向异性能和极小的超顺磁临界尺寸,已成为制备图案化介质的一大热点材料。目前,制备工艺仍是图案化磁记录研究的主要挑战之一,现阶段主要有三种方法:一种方法是使用刻蚀印刷技术,但由于非常费时和高造价且它仅用于极小规模制备;另一种方法是自组装制备技术,抑制退火过程中粒子聚集和确保易磁化轴的高度有序排列仍需要深入研究;最后一种方法是模板合成技术,它能有效改善上述问题。本文采用模板合成技术,在孔径和厚度都较易调控的阳极氧化铝(AAO)模板上溅射制备FePt纳米点阵。本文首先介绍了磁控溅射系统及其机理,同时对模板及样品的微观分析和磁性能测试作了相关阐述。接下来,本文先采用极紫外光刻和ICP刻蚀等工艺成功制备了Si基二维有序微米孔模板,然后使用两步阳极氧化法制备纳米级多孔氧化铝模板,并通过调节实验参数制备出不同周期和孔径的AAO模板。最后,本文采用磁控溅射和定量刻蚀在阳极氧化铝模板上成功制备出FePt纳米点阵列,并详细探讨Ag底层、退火温度与模板孔径对FePt纳米点阵磁性能的影响,研究结果表明Ag底层能大幅度提升Fe Pt纳米点阵的垂直矫顽力,600°C退火后的FePt纳米点阵呈现出显著的L10相结构并具有较高的硬磁性能,80nm孔径模板相比40nm孔径模板更有利于FePt纳米颗粒的沉积与垂直磁性能的提高。更多还原

【Abstract】 The patterned magnetic recording technology uses the two-dimensional ordered magnetic nano arrays as recording medium, and it can break the superparamagnetic limit in the conventional continuous magnetic recording medium, and it is possible to increase the recording areal density of a hard disk to 5Tb/in2. The key of patterned recording technology to practical development is to develop a high-performance patterned magnetic recording medium, the FePt become has become a hot topic material in the preparation of the patterned magnetic media due to its ultra high magnetic anisotropy and ultra low superparamagnetic critical dimension.Currently, the preparation process is still one of the major challenges in the research of the patterned magnetic recording, and there are three main approach: one approach is to use etching printing technology, which is very time-consuming and high-costly and can only used for small production. Another approach is the self-assembly of magnetic nanoparticles, but suppress the particle aggregation during annealing and guarantee highly ordered aligning of magnetic easy axis need further study. The last approach is to use porous templates to induce the synthesis of nanostructures, it can effectively solve the above problems in the previous two approaches. This paper used the anodic aluminum oxide(AAO) templates, because of its pore size and thickness can easily be regulated oxidizing conditions.This paper introduced the magnetron sputtering system and its work principle, and microscopic analysis and magnetic properties test of the templates and samples. Then the micron-sized array templates were successfully prepared in Si chip using the traditional lithography and ICP etching technology, and the nano-porous anodized alumina templates with different periods and pore diameters were also fabricated by tuning the experimental parameters during the two-step anodization processes. Finally, Fe Pt nanodot arrays wereprepared by the magnetron sputtering and quantificational etching on AAO templates and the effect of Ag underlayer, annealing temperature and pore diameter on the magnetic properties of FePt nanodot arrays were also discussed in detail. The research results show that Ag underlayer can greatly enhance the perpendicular coercivity of FePt nanodot arrays, the arrays post annealed at 600°C exhibit significant L10 phase and have high hard magnetic properties, AAO templates with pore diameter of 80 nm are more conducive to the deposition of FePt nanoparticles and the improvement of the perpendicular magnetic properties than those with pore diameter of 40 nm.更多还原