SGER: New Magnetic Tunnel Junctions Using Semiconductor Sandwich Layers with Controllable Band Gaps

SGER：使用带隙可控的半导体夹层的新型磁隧道结

• 批准号: 0100799
• 负责人: David Jiles
• 金额: $ 4.98万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0100799&HistoricalAwards=false
• 关键词: SGER; New; Magnetic; Tunnel; Junctions

D.C.Jiles and J.E.SnyderProgress beyond data storage densities of 100 Gbits/in2 requires a revolution in materials. Magnetic tunnel junctions provide a possible solution and are expected to form an essential component of future magnetic disk drive read heads, part of the $50 billion/year hard disk drive industry. Tunnel junctions with a R/R of 30% have been announced in the last year. However there are serious problems with the current generation of tunnel junctions, which are based exclusively on an alumina barrier layer. These layers are now down to 0.7 nm in thickness and still the resistances of the tunnel junctions are too high for the intended applications. Essentially the alumina tunnel junction has reached its ultimate performance limits and there is a concern if alumina tunnel junctions will ever be able to be used in read heads and MRAM because of the high resistance. Therefore it is time for new tunnel junction materials to be brought forward based on alternative barrier layers. Recently studies of alternative insulator materials by Fert et. al. showed that the barrier layer strongly affects the spin polarization in the magnetic layers. Freitas et al. have studied the effect of nitrogen additions to the alumina which changed the barrier height and resulted in an increase in tunnel magnetoresistance from 22% to 25% as the composition changed from Al2O3 to AlN. However none of this has addressed the central problem of the overall resistance of the devices. In our proposed SGER we intend to make the radical change of completely replacing the alumina with other semiconductors. Of course this is a high risk endeavor, but the enormous benefits to the magnetic data storage industry that will accrue if the project is success make this a worthwhile exploratory investigation.

D.C.Jiles和J. E. Snyder数据存储密度超过100 Gbits/in 2需要材料革命。磁隧道结提供了一种可能的解决方案，并有望成为未来磁盘驱动器读取头的重要组成部分，这是每年500亿美元硬盘驱动器行业的一部分。去年已宣布了R/R为30%的隧道连接。然而，目前这一代隧道结存在严重的问题，这些隧道结完全基于氧化铝阻挡层。这些层的厚度现在下降到0.7 nm，但隧道结的电阻对于预期的应用来说仍然太高。基本上，氧化铝隧道结已经达到其最终性能极限，并且由于高电阻，人们担心氧化铝隧道结是否能够用于读取头和MRAM。因此，现在是时候提出新的隧道结材料的基础上替代的势垒层。Fert等人最近对替代绝缘体材料的研究。显示势垒层强烈地影响磁性层中的自旋极化。Freitas等人已经研究了向氧化铝中添加氮的效果，其改变了势垒高度，并且导致随着组成从Al 2 O3变为AlN，隧道磁阻从22%增加到25%。然而，这些都没有解决设备的整体电阻的中心问题。在我们提出的SGER中，我们打算进行彻底的改变，用其他半导体完全取代氧化铝。当然，这是一个高风险的奋进，但巨大的利益，磁数据存储行业，将积累，如果该项目是成功的，使这是一个值得探索的研究。