Magnetic Anisotropy Of CoFeB/Semiconductor Heterostructures

In past decades, the information technology (IT) industry has followed Moore’s law, that the number of transistors on a chip doubles about every 2 years, but conventional solid state electronics may soon reach a limit due to the increasing heat dissipation challenges of charge current and quantum size effects in small devices. Spintronics along with advances in nanotechnology are expected to ensure continued adherence to Moore’s law in the future. Within the context of spintronics, the electron’ spins, not just their electrical charge, are manipulated within electronic circuits. These spintronic devices are anticipated to be nonvolatile, versatile, fast, and capable of simultaneous data storage and processing, while consuming less energy. They already play an increasingly significant role in high density data storage, magnetic sensors, quantum computing and so on.The study of the ferromagnetic (FM)/semiconductor (SC) heterostructure plays an important role in the new generation of spin electronics. Many works combined epitaxial growth using molecular beam epitaxy and various nano manufacturing technology to study hot topics like:1) insert thin layer between ferromagnetic films and substrate to enhance the spin injection efficiency,2) study the size effect of spin lifetime,3) the influence of the reconstruction on the semiconductor surface,4) the realization of charge induced change of magnetic properties and 5) photon induced change of spin polization.In this dissertation,we grow amorphous CoFeB films on GaN and InAs substrates, respectively, using magnetron sputtering, which can be used in industrial production. Uniaxial magnetic anisotropy was found in both structures. Low resistance ohmic contact was detected in CoFeB/InAs heterostructure, which promises this structure a good candidate for spin devices.