双势垒磁性隧道结的磁电阻效应及其在自旋晶体管中的应用  

Magnetoresistance effect of double-barrier magnetic tunneling junction applied in spin transistors

作　　者：曾中明[1] 韩秀峰[1] 杜关祥[1] 詹文山[1] 王勇[2] 张泽[2] 

机构地区：[1]中国科学院物理研究所(凝聚态物理国家实验室)磁学国家重点实验室,北京100080 [2]中国科学院物理研究所(凝聚态物理国家实验室)先进材料与结构分析电镜实验室,北京100080

出　　处：《物理学报》2005年第7期3351-3356,共6页Acta Physica Sinica

基　　金：国家重点基础研究发展规划项目(批准号:2001CB610601);中国科学院知识创新工程;国家自然科学基金(批准号:50271081;10274103);国家杰出青年基金(批准号:50325104)资助的课题.~~

摘　　要：利用磁控溅射方法沉积双势垒磁性隧道结多层膜,其中Al_O势垒层由等离子体氧化1nm厚的金属铝膜方式制备,然后采用深紫外光曝光和Ar离子刻蚀技术、微加工制备出长短轴分别为6和3μm大小的椭圆形双势垒磁性隧道结(DBMTJ),并在室温和低温下对其自旋电子输运特性进行了研究.DBMTJ的隧穿磁电阻(TMR)比值在室温和4.2K分别达到27%和42.3%,结电阻分别为13.6kΩ·μm2和17.5kΩ·μm2,并在实验中观察到平行状态下存在低电阻态及共振隧穿效应,反平行态下呈现高电阻态以及TMR随外加偏压或直流电流的增加而发生振荡现象.由此,设计了一种基于这种双势垒磁性隧道结隧穿特性的自旋晶体管.The multilayer films of the double-barrier magnetic tunneling junctions (DBMTJs) were deposited by magnetron sputtering. The AlOx, insulator was formed by plasma oxidizing aluminium. The photolithographic pattering procedure combined with Ar ion milling was used to microfabricate the DBMTJs with an ellipse of pi x 3 x 6 mu m(2). Magnetic transport properties of DBMTJs were investigated. The junctions show a resistance-area product about 13.6 k Omega - mu m(2) and 17.5 k Omega - mu m(2), a high tunneling magnetoresistance of 27% and 42.2% at 300 K and 4.2 K, respectively. A tunneling magnetoresistance oscillation phenomenon with respect to the bias voltage was first observed in this experiment. We designed a few kind of spin transistors based on the spin-dependent resonant tunneling effect of the DBMTJs.

关 键 词：磁性隧道结 自旋晶体管 双势垒 磁电阻效应 应用 等离子体氧化 电子输运特性 隧穿磁电阻 磁控溅射 刻蚀技术 加工制备 隧穿效应 振荡现象 直流电流 外加偏压 多层膜 势垒层 紫外光 椭圆形 低电阻 TMR 高电阻 室温 短轴 

分 类 号：O471[理学—半导体物理]