Fabrication of giant magnetoresistant devices using electron beam evaporation

Abstract

<p>The discovery of Giant Magnetoresistance (GMR) in 1988 was of great importance to both the research community and industry. The existence of GMR effects has allowed for increase in hard drive storage capacity, and has future potential for use in non-volatile memory and spin-valve transistors. GMR effects are seen in stacks of thin ferromagnetic materials separated by non-magnetic spacer layers. Layer thicknesses are normally on the order of 10 to 50Å. GMR sandwich structures using Nickel Iron Cobalt (NiFeCo) alloy, Iron Cobalt (FeCo) alloy, Tantalum (Ta), and Copper (Cu) were deposited using Electron Beam (E-beam) Evaporation techniques on Silicon (Si) wafers. A fabrication process was developed to use equipment available at the Microelectronic Research Center. The structures were tested with bulk measurement techniques, Van der Paw patterned measurements, and bar resistor measurements. Films were further characterized using four-point probe resistivity measurements, Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD).</p>