Measurement And Characterization Of Correlation Effect Between ISHE And Magnetoresistance Of NiFe/Ta Thin Film

With the rapid development of the integrated circuit industry,the integration level of devices is increasing,and their size is approaching the classical limit.The development of microelectronics along the direction of Moore’s Law is facing severe challenges.Spin electronic devices,on the other hand,have the potential to bring about a breakthrough in the information industry with faster response speeds,higher energy storage density,and lower power consumption.The core of spin electronic devices lies in the generation and detection of spin currents,and the use of spin Hall effect to generate pure spin currents is an effective means.In this paper,the influence of the geometric size effect of the sample on the inverse spin Hall voltage is investigated,and an automated electrical testing system is used to characterize the inverse spin Hall effect of Ni Fe/Ta bilayer films with different aspect ratios.First,a coaxial line consisting of short-circuited inner and outer conductors was used to construct a short-circuit microwave probe,which provided a microwave magnetic field in the local area.With the assistance of an electromagnet and a displacement stage,automated field scanning tests of the sample array were performed.By testing a sample array consisting of 3 rows and 9 columns,voltage signals at multiple frequencies were fitted to obtain the magnetic parameters of the samples.It was found that parameters such as the damping coefficient and saturation magnetization intensity of the samples were position-dependent,which was caused by the non-uniformity of the thin film system.Next,10 Ni Fe/Ta bilayer film samples with widths ranging from 610μm to 700μm were prepared,and inverse spin Hall effect electrical tests were performed on them.The experimental results showed that the sample width affected the symmetry and amplitude of the tested voltage signal.By fitting and separating the symmetric component A_D and the antisymmetric component A_L,it was found that the normalized A_D,as a function of width,increased monotonically,consistent with the relationship between AMR_⊥and V_SRE.By adjusting the probe height and changing the microwave magnetic field applied to the sample,the difference in the test results under different microwave magnetic fields gradually decreased as the sample width increased.Therefore,when the width is relatively large,the dominant factor affecting the ratio of A_D to A_L under different microwave magnetic fields within a certain range is the variation in the anisotropic magnetoresistance caused by increasing width,which makes the ratio approach each other.Finally,by testing samples with different widths by flipping them,the inverse spin Hall voltage V_ISHE was separated,and it was experimentally verified that AMR_⊥only affects V_SRE and that width variation does not affect the spin-charge conversion efficiency.This provides some guidance for the electrical testing and analysis of the inverse spin Hall effect and enables the adjustment of V_SRE through control of the sample width.