低矫顽力GMR磁传感器及其单畴模型的研究  

Study on GMR Magnetic Sensor with Low Coercivity and the Single Domain Model

作　　者：刘鹏[1] 李伟[1] 叶双莉[1] 任天令[1] 刘理天[1] 

机构地区：[1]清华大学微电子学研究所,北京100084

出　　处：《微纳电子技术》2007年第7期216-218,共3页Micronanoelectronic Technology

摘　　要：在硅片上制备结构为Ta/NiFeCr/NiFe/CoFe/Cu/CoFe/IrMn/Ta的IrMn顶钉扎自旋阀薄膜,并最终制成了一组基于此自旋阀结构的GMR磁传感器芯片。利用弱磁场下的退火工艺,改变薄膜易磁化轴的方向,当退火温度为150℃、外加磁场为120Oe时,GMR芯片的矫顽力可以降至0.2Oe以下。同时建立了一种自旋阀自由层的单畴模型,用以解释这一退火效应。利用Mat-lab计算GMR芯片的Meff-H曲线,所得到的计算结果与实验结果一致。所以,自旋阀自由层易磁化轴的方向与GMR磁传感器的性能有着密切的关系。IrMn top spin valves, with the structure of Ta/NiFeCr/NiFe/CoFe/Cu/CoFe/IrMn/ Ta, were formed on Si substrate. A series of GMR（giant magnetic resistance） magnetic sensor chips were fabricated based on these spin valves. By an annealing procedure with a weak applied magnetic field, the direction of the easy axis of spin valve films could be changed. When the annealing temperature was 150 ℃ and the magnetic field was 120 Oe, the coercivity of the GMR chips could be reduced to less than 0. 20e. In addition, a single domain model of free layer in spin valve was established to explain the annealing effect. After simulating the Me~〈H curves of the GMR chips, the simulation results coincide with the experiment results. Therefore, the performance of the GMR magnetic sensors is strongly related to the direction of the easy axis of free layer in spin valves.

关 键 词：巨磁电阻传感器 自旋阀 矫顽力 退火 单畴模型 

分 类 号：TP212.13[自动化与计算机技术—检测技术与自动化装置]