FeCo基软磁薄膜的制备及其微波软磁特性研究

发布时间：2018-02-22 15:02

本文关键词： 高频软磁薄膜铁磁共振单轴磁各向异性磁电耦合涡旋磁各向异性　出处：《青岛大学》2015年硕士论文　论文类型：学位论文

【摘要】：当今集成电路(IC,Integrated circuits)电子产品飞正向着轻薄短小、高频化、宽频化、低功耗和多功能化趋势飞速发展,这对电子器件和作为电子元器件的基础材料提出了更高的要求。因为电感元件尺寸大,难以集成到广泛应用的集成电路中。随着薄膜技术和纳米科学的进步,能够适用于集成电路平面构型的软磁薄膜,因为可以大大减小电感尺寸,而使得平面型微磁电感有望集成到集成电路中。平面微磁电感要求相应的软磁薄膜具有高的铁磁共振频率、磁导率、损耗和集成电路IC兼容性制备工艺。为了在IC兼容工艺条件下,制备良好的软磁薄膜,本论文以饱和磁化强度MS大的FeCo基合金为母体,利用自主研发的成分梯度溅射方法添加Al2O3,获得了性能优良的高频磁性薄膜材料。具体的研究工作主要有:(1)利用成分梯度溅射法(CGS,Composition gradient sputtering)和磁电耦合法(MEC,magnetoelectric coupling)相结合,两步提升铁磁共振频率。首先,在单晶Si片上,利用成分梯度溅射方法,制备了具有Al和O成分梯度的单轴磁各向异性FeCo AlO薄膜,其零偏置磁场条件下的铁磁共振频率fFMR高达5.4 GHz;然后,选择综合性能优越的区间,在相同的条件下,用(011)解理的PZN-PT铁电单晶衬底代替Si衬底的相应位置,在PZN-PT衬底上溅射得到FeCoAlO成分梯度薄膜复合体系。令人兴奋的是该复合体系的铁磁共振频率fFMR在成分梯度诱导的应力梯度和磁电耦合作用的双重作用下,从3.4 GHz提升到9.6 GHz,单轴磁各向异性场HK也从100 Oe提高到735 Oe。研究表明,CGS和MEC相结合,可以实现铁磁共振频率的协同增强,将铁磁共振频率提高的X波段,为FeCo Al O薄膜在微波磁性器件中的应用前景奠定基础。(2)宏观涡旋磁各向异性的构建。利用成分梯度溅射方法构建了具有宏观涡旋磁各向异性结构的纳米晶CoFeAlO CGS薄膜。由于切向和径向残余应力的竞争作用,使得总应力由张应力向压应力过渡,从而导致易磁化轴由径向(R方向)逐渐过渡到切向(T方向),于是样品呈现出宏观涡旋磁各向异性的特征。CGS方法沉积的FeCo AlO成分梯度薄膜表现出良好的高频铁磁特性与高磁导率约100,截止频率在2 GHz和Qm因子超过50。
[Abstract]:Nowadays, IC Integrated Circuit (IC) electronic products are developing rapidly towards the trend of being short, thin and short, high frequency, wide frequency, low power consumption and multifunction. This puts forward higher requirements for electronic devices and the basic materials used as electronic components. Because of the large size of inductors, it is difficult to integrate into widely used integrated circuits. With the development of thin film technology and nanoscience, Soft magnetic thin films that can be applied to planar configurations of integrated circuits, because they can greatly reduce the size of inductors, The planar micromagnetoelectric inductance is expected to be integrated into the integrated circuit. The planar micromagnetoelectric inductance requires the corresponding soft magnetic thin film to have high ferromagnetic resonance frequency, magnetic permeability, In order to prepare good soft magnetic thin films under IC-compatible conditions, FeCo alloy with high saturation magnetization is used as the matrix in this thesis. High frequency magnetic thin films with excellent properties were obtained by adding Al _ 2O _ 3 into Al _ 2O _ 3. The main research work includes: (1) using component gradient sputtering method (CGSN composition gradient sputterings) and magneto-electric coupling method (magnetoelectric coupling). Firstly, uniaxial magnetic anisotropic FeCo AlO thin films with Al and O composition gradient were prepared on single crystal Si substrates by component gradient sputtering. The frequency of ferromagnetic resonance (fFMR) at zero bias magnetic field is as high as 5.4 GHz. Then, the region with superior comprehensive performance is chosen, and the corresponding position of Si substrate is replaced by the cleavage PZN-PT ferroelectric substrate under the same conditions. The FeCoAlO composition gradient film composite system was prepared by sputtering on PZN-PT substrate. It is exciting that the ferromagnetic resonance frequency (fFMR) of the composite system is affected by the stress gradient induced by the composition gradient and the magnetoelectric coupling effect. From 3.4 GHz to 9.6 GHz, the uniaxial magnetic anisotropy field HK is also raised from 100Oe to 735Oe. The results show that the combination of CGS and MEC can realize the synergistic enhancement of ferromagnetic resonance frequency and increase the frequency of ferromagnetic resonance in X-band. In order to lay a foundation for the application prospect of FeCo AlO thin film in microwave magnetic devices, the structure of macroscopic vortex magnetic anisotropy was established. The nanocrystalline CoFeAlO CGS thin films with macroscopic vortex magnetic anisotropy structure were constructed by component gradient sputtering method. Film. Due to the competitive effect of tangential and radial residual stresses, Make the total stress transition from tensile stress to compressive stress, As a result, the magnetization axis gradually transitioned from the radial direction to the tangential direction, and the samples showed the characteristics of macroscopic vortex magnetic anisotropy. The FeCo AlO gradient films deposited by the CGS method showed a good high frequency ferromagnetism. The cutoff frequency is 2 GHz and QM factor is more than 50.
【学位授予单位】：青岛大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.2;TN405

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