Spin valve with perpendicular anisotropy for spin torque experiments
EMSL Project ID
29394
Abstract
We propose a research project directed at the study of spin torque effects in multilayer spin valves with perpendicular magnetic anisotropy for magnetic random access memory applications. The spin valve structure with perpendicular anisotropy will consist of two (Co/Pt) multilayers with different coercive fields separated by a non-magnetic (Cu) layer. The structure will be shaped in a vertical pillar, where spin-polarized current will be applied along the pillar axis and perpendicular to the layers plane. A traditional approach to fabrication of current-perpendicular-to plane spin valves includes complex multi-step lithography. In order to reduce lithographic difficulties (the pillar needs to be on the order of 50-100 nm in diameter, the combined height on the order of 30 nm), we propose replacing the traditional lithography with deposition into a pre-fabricated vertical via in an insulating support film. This method can potentially lead to the development of a new fabrication technique suitable for applications. Fabrication of the via in an insulator film deposited on a metal bottom contact layer will be performed at EMSL using the FEI Helios Nanolab dual-beam focused ion beam/scanning electron microscopy (FIB/SEM) microscope which has unique FIB capability for nanoscale FIB micromachining suitable for achieving the goal of the project. The ion beam etching of the insulator needs to be stopped immediately upon reaching the bottom metal contact, which is required to ensure the following presicion deposition of the flat multilayers. The film deposition steps including the bottom contact and insulator layer before FIB, followed by the magnetic multilayer and the top contact layer after the FIB step, will be performed at UW by ion beam sputtering. The PIs laboratory has considerable experience in preparation and investigation of magnetic multilayer films with perpendicular magnetic anisotropy. This proposal suggests a new approach to investigation of interfacialy-controlled properties of novel magnetic memory elements and is in line with the research direction "Science of Interfacial Phenomena: Tailored Interfacial Structures for Dynamics, Reactivity, and Transport". The Krishnan group at UW has a successful history of interactions with PNNL on a number of research projects funded by both NSF/ECS and DoE/DMS.
Project Details
Project type
Exploratory Research
Start Date
2008-04-04
End Date
2009-04-05
Status
Closed
Released Data Link
Team
Principal Investigator