Development of Spin Valve type of Static Memory Devices using GMR Effect

用双离子束溅射装置在Fe缓冲层上沉积了厚度为10 ~ 35的Ni-Fe和Cu巨磁多层膜。用辅助离子辐照Ni-Fe/Cu膜界面，研究了亚离子辅助电压V_0 ~ 350 V范围内巨磁电阻效应的变化<sub>。离子辅助辐照虽然使磁电阻率的幅值略有下降，但磁电阻的场灵敏度得到了较大的提高，在160 V处达到最大值<sub>。由于通常沉积在多层膜上的用于施加交换偏置场的Fe-Mn层抗腐蚀性差，易被氧化，提出了在衬底上直接淀积FeMn层，再在其上淀积Ni-Fe/Cu/Ni-Fe层的反向自旋阀结构，通过在具有良好（111）取向的Ni-Fe层上淀积，并利用离子辅助辐射，成功地存款了具有（111）取向的FeMn层。在（111）取向的FeMn层上沉积Ni-Fe/Cu/Ni-Fe多层膜具有较好的磁电阻比和良好的场敏感性。这种多层膜的交换偏置场约为20 Oe，可以作为自旋阀器件工作，表明这种自旋阀多层膜有可能通过光刻技术作为静态存储器件。

The giant magnetic multilayrs composed of Ni-Fe and Cu layrs whose thickness were from 10 to 35 A each were deposited on Fe buffer layr by using the dual ion beam sputtering apparatus. Assist ions were radiated to the interfaces between Ni-Fe and Cu layr and the change of giant magneto-resistance (GMR) effect on sub ion assist voltage V_<sub> from 0 to 350 V was investigated. Although the amplitude of magneto-resistivity (MR) ratio was slightly decreased, the field sensitivity of magneto-resistance was fairly improved by ion assist radiation and took the maximum value at V_<sub> of 160 V.Since Fe-Mn layr, which is commonly deposited on top of the multilayrs and used for applying exchange bias field, has poor corrosion resistivity and is easily to be oxidezed, we proposed the reversed type spin valve structure, in which FeMn layr is deposited on substrate directly and Ni-Fe/Cu/Ni-Fe layrs was deposited on it. We succeeded to deposit FeMn layr with (111) orientation by deposited on Ni-Fe layr with well (111) orientation and ion-assist radiation. Ni-Fe/Cu/Ni-Fe layrs deposited on FeMn layr with (111) orientation possessed relatively well MR ratio and excellent field sensitivity. The exchange bias field of about 20 Oe was achieved in this type of multilayrs and it worked as spin valve device.It seemed that the spin valve multilayrs deposited in this study has possibility to be applied as static memory device by using lithographic technology.