Fabrication process for hybrid magnetic material and fabrication of tunnel magnetoresistive read head

在使用隧道磁性连接点的读取头、隧道连接点的优化（分层结构、堆叠序列、最佳退火条件、障碍层的厚度）中，并已研究过微制造过程。两种读头的人被成功地证明了。主要结果按以下顺序汇总：1. The Ta30（）/Ni_<80>Fe_<20>（30）/Cu（200）/IrMn（100）CoFe（40）/Al-oxide/CoFe（40）/Ni_<80>Fe_<20>（200）/Ta（50） junction annealed at 250 for 1 h exhibited that the values of resistance times cross section and tunnel magnetoresistance ratio were 78 m^2 and 33%， respectively.2。使用光成像和氩离子铣削过程，我们用3 x3 μm^2制造了一个小交叉点。在另一边，带有0.5 × 0.5 μm^2的小交叉点被发现使用电子束光刻，没有损坏被确认为与交叉点比较的运输性能测量前后的传输性能。隧道磁性读取头的可行性，带有流体导向层的扫描磁带存储应用程序被调查。一个长距离交换偶联方案，有一个冷却层和一个防磁网被储存在隧道阀元件的顶部自由层上，已被雇用。如果要在自由层中稳定域结构，则长距离交换偶联偏差由常规永久磁铁偏差方法组合。通量指南型阅读器的最大输出电压为1.75 mV_&lt;p-p&gt;，其对应于一个传统的异晶磁性阅读器+1.5分贝。Furthermore，一个用于硬盘应用程序的隧道磁性读取头已制造，输出电压相应地达到10 Gb/英寸^2已实现。

In order to fabricate a read head using tunnel magnetoresistive junction, optimization of the tunnel junction (layered structure, stacking sequence, optimal annealing condition, thickness of barrier layer) and micro-fabricating process have been studied. Two kinds of read head were successfully demonstrated. The main results are summarized as follows.1. The Ta30(Å)/Ni_<80>Fe_<20>(30Å)/Cu(200Å)/IrMn(100Å)CoFe(40Å)/Al-oxide/CoFe(40Å)/Ni_<80>Fe_<20>(200Å)/Ta(50Å) junction annealed at 250 ℃ for 1 h exhibited that the values of resistance times cross section and tunnel magnetoresistance ratio were 78 Ω・μm^2 and 33 %, respectively.2. Using the photolisography and Ar ion milling process, we fabricated a small junction with 3x3 μm^2. On the other hand, small junction with 0.5x0.5 μm^2 was obtained by using electron beam lithography and no damage was confirmed for the junction by comparing the transport property measured before and after micro fabrication.3. Feasibility of tunnel magnetoresistive read head with flux-guide layers was investigated for helical-scan tape storage applications. A long-range exchange coupling bias scheme, with a Cu layer and an antiferromagnet were deposited on top of free layer in the tunnel-valve element, was employed. In order to stabilize domain structures in the free layer, the long range exchange coupling biasing was combined with conventional permanent magnet bias method. The maximum output voltage of the flux guide type reader was 1.75 mV_<p-p> which was corresponding to +1.5 dB of a conventional anisotropic magnetoresistive reader. Furthermore, a tunnel magnetoresistive read head for HDD application was fabricated and an out put voltage corresponding to 10 Gb/inch^2 was realized.