NiFe薄膜AMR效应及器件化的研究

发布时间：2018-03-01 04:12

  本文关键词： AMR 表面粗糙度 磁灵敏度 饱和磁场 磁阻开关芯片　出处：《电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：NiFe薄膜材料由于其具有较高的居里温度、较大的各向异性磁阻效应(Anisotropic magnetoresistance effect,AMR)、较高的灵敏度以及低廉的价格等特点使其成为开发磁性传感器首选的材料。本论文研究内容是通过实验研究获得较高AMR值、较低饱和磁场、较高灵敏度的NiFe磁性薄膜,并将其与相应的信号处理电路集成,制成磁阻传感芯片。首先,研究了不同NiFe层厚度(t)对薄膜AMR值、磁灵敏度(Smax)以及饱和磁场(Hs)的影响。结果表明,随着t的增大,AMR值和Smax值都是先增大后减小,在t=12 nm时AMR达到最大值1.25%,Smax达到最大值0.18,Hs先减小后增大,在t=12 nm时达到最小值12.5 Oe。其次,研究了在倾斜溅射状态下NiFe薄膜易磁化轴的取向规律。结果表明:在倾斜状态下,NiFe薄膜易化轴方向会沿着圆盘转动的切线方向,且经过真空磁场退火后易磁化轴与退火时添加的磁场方向一致。优化了磁场退火工艺中退火温度、退火时间对NiFe薄膜AMR值、磁灵敏度(Smax)以及饱和磁场(Hs)的影响。结果表明:随着退火温度的增加,NiFe薄膜的AMR值、Smax值以及饱和磁场(Hs)都是先增大后减小,在400℃时AMR达到最大值1.68,Smax达到最大值0.48,Hs先减小后增大,在300℃达到最小值5 Oe。随着退火时间增加,NiFe薄膜的AMR值先增大后减小,在3 h时达到最大值1.78%,Smax值先增大后减小,在5 h时达到最大值0.65,Hs先减小后增大,在3 h达到最小值4.9Oe。此外,还研究了在倾斜溅射状态下基片表面粗糙度对于NiFe薄膜磁性能的影响。结果表明:随着σ从0.6 nm逐渐增大到1.12 nm,AMR值由1.05%逐渐减小到0.6%,幅值达43%,Smax值由0.12减小到0.025,幅值达79.17%,Hs由15.04 Oe逐渐增大到42.87 Oe,增幅达185%。随着σ的增大,在易磁化轴方向上在易磁化轴方向上饱和磁化强度(M)由从1160 KA/m减小到1120 KA/m,减小幅度达3.4%;矫顽力(Hc)由3.6 Oe逐渐增大到6 Oe,增大幅度达66%,而在难磁化轴方向上Hc与M随σ的变化不明显。最后,测试了磁阻开关芯片的性能,发现芯片具有优异的开关性能,已经达到国外同类产品的性能。
[Abstract]:Because of its high Curie temperature, NiFe thin film material, The large anisotropic magnetoresistive effect and the high sensitivity and low price make it the preferred material for the development of magnetic sensors. The content of this thesis is to obtain higher AMR value and lower saturation magnetic field by experimental study. The magnetoresistive sensing chip is fabricated by integrating the high sensitivity NiFe magnetic film with the corresponding signal processing circuit. Firstly, the effects of different NiFe layer thickness on the AMR value, magnetic sensitivity Smax) and saturation magnetic field (Hsss) of the film are studied. With the increase of t, the value of AMR and Smax increased first and then decreased. The maximum value of AMR reached 1.25nm, and the maximum value of Smax decreased first, then increased, and reached the minimum value of 12.5Oeat 12nm. The orientation of the magnetization axis of NiFe thin films under inclined sputtering is studied. The results show that the orientation of the facilitation axis of nife thin films in inclined state is along the tangent direction of the disk rotation. The magnetization axis after vacuum magnetic field annealing is in the same direction as the magnetic field added during annealing. The annealing temperature and annealing time are optimized to the AMR value of NiFe film. The results show that with the increase of annealing temperature, the AMR value and the saturation magnetic field value of nife films increase first and then decrease. At 400 鈩，

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