Research on Prototype of Sputtering Apparatus for Spinic Data Storage Media

研究小组目前正在研究一种新的磁记录范式，即“脊椎存储”，以建立一个新的工程领域，其中每个记录的比特存储在几个单畴晶体中，以实现超高密度的磁记录。本项目旨在为这一全新的方案开启记录介质制作技术的研究。它一直致力于为媒体提供设计指南。特别是，为了优化作为高密度记录介质，其记录层的微磁结构旨在从溅射沉积的物理角度进行澄清。1996年初，研制成功了高真空溅射装置，该装置具有专门用于高真空的铝腔，并确定了背景压力为10^<-8> Torr。该装置用于制备高密度磁记录盘，用于读写实验。该装置最终在1996年底达到了10^<-9 b>…More Torr的更高真空度。在溅射条件优化后，对高密度介质的读写性能进行了评价。所得结果如下：(a)在Co-Cr垂直各向异性薄膜的记录层中出现了低噪声磁记录介质不可缺少的细晶粒结构，(b)更高的真空带来更好的垂直各向异性，(c)观察到Co-Cr薄膜的成分分离，因此(d)降低介质噪声作用的晶粒之间的磁分离增强，但(e)晶粒尺寸变得较大，影响了增加噪声的效果。(f)在噪声测量中，其介质噪声小于普通真空溅射样品。如前所述，该项目基本满足了项目开始时对溅射装置的要求，并获得了高性能垂直介质的一些知识。溅射装置制备的介质在完成溅射条件的优化后，表现出优异的读写性能，特别是高SN比。这些结果将是理想的脊髓存储介质的第一步，并将为实现超高密度记录奠定基础。少

The research team is now investigating a new paradigm of magnetic recording, or "Spinic Storage, " for establishment of a new field of engineering, in which each recorded bit is stored in several single-domain crystallites in order to attain ultra-high density magnetic recording. The aim of this project is to initiate research on fabrication technology of recording media for this new strage scheme. It has been focused to provide a design guideline for the media. In particular, to optimize as a medium for high density recording, its micro magnetic structure of the recording layr is aimed to be clarified from physics of sputtering deposition.In early 1996, high vacuum sputtering apparatus having an aluminum chamber specialized for such high vacuum was built up, and background pressure of 10^<-8> Torr was confirmed. The apparatus was used for preparing high density magnetic recording disks for read/write experiments. The apparatus has been eventually attained much higher vacuum of 10^<-9> … More Torr in late 1996. Evaluation of read/write performance as a high density medium has been performed after optimization of sputtering conditions. The results described below have been obtained : (a) fine grain structure, which is indispensable for low noise magnetic recording media, appeared in recording layr of Co-Cr perpendicular anisotropy film, (b) higher vacuum brought better perpendicular anisotropy, and (c) compositional separation of the Co-Cr film was observed, therefore, (d) magnetic separation among the grains which acts to reduce medium noise was enhanced, however, (e) grain size became rather large, which affects the effect of increase the noise, and (f) in noise measurement its medium noise was smaller than samples by normal vacuum sputtering as a result.As described, the original requirements for the sputtering apparatus at the start of this project has been almost satisfied, and several knowledge for the high performance perpendicular media was obtained. The media prepared by the sputtering apparatus showed superior read/write characteristics, in particular its high SN ratio, after finishing its optimization of sputtering conditions. These results will be a first step of the ideal Spinic Storage Media, and it will be a basement for realization of ultra-high density recording. Less