AVS 50th International Symposium
    Magnetic Interfaces and Nanostructures Thursday Sessions
       Session MI+SC-ThM

Paper MI+SC-ThM3
Characterization of AlGaN and AlN Based Dilute Magnetic Semiconductors

Thursday, November 6, 2003, 9:00 am, Room 316

Session: New Spintronic Materials
Presenter: R.M. Frazier, University of Florida
Authors: R.M. Frazier, University of Florida
G.T. Thaler, University of Florida
J. Stapleton, University of Florida
C.R. Abernathy, University of Florida
S.J. Pearton, University of Florida
M.L. Nakarmi, Kansas State University
J.Y. Lin, Kansas State University
H.X. Jiang, Kansas State University
R. Rairigh, University of Florida
J. Kelly, University of Florida
A.F. Hebard, University of Florida
J.M. Zavada, U. S. Army Research Office
R.G. Wilson, Consultant
Correspondent: Click to Email
The realization of room temperature ferromagnetism in GaN@footnote 1@ has ignited interest in the development of magnetic devices based on existing wide bandgap technology. However, in order to integrate magnetic semiconductors into the existing technology, it may be necessary to tailor the bandgap through addition of Al. Thus, AlGaN and AlN are two promising candidates for investigation, but optimization of the material in terms of choice of dopant, magnetic characteristics and crystalline quality is necessary before device fabrication can be undertaken. Ion implantation has been shown to be an effective survey method for optimization of dopant type and concentration. In this study, AlGaN and AlN grown on sapphire substrates by Metal Organic Chemical Vapor Deposition have been implanted with Mn, Cr, and Co at high doses (3x10@super 16@ cm@super -2@, 250 keV). After implantation the samples were annealed at 900°C for activation. Photoluminescence of the AlGaN-based alloys showed no band-edge luminescence before or after ion implantation, but the implantation process did introduce deep emission lines. In AlN, the Co and Cr doped films showed hysteresis at 300K while the Mn doped material did not. Epitaxial AlMnN by contrast does show hysteresis at room temperature suggesting that defects may be deleterious to magnetic ordering. The effects of dopant type and host conductivity type on the magnetic and electrical properties after implantation into AlGaMnN will also be presented. The work was supported by the Army Research Office under ARO-DADD19-01-0-0701, ARO-DAAF190110701 and DAAF 19021420 and by NSF under ECS-0224203, DMR 0101856, and DMR 0101438. @FootnoteText@ @footnote 1@ G. T. Thaler, M. E. Overberg, B. Gila, R. Frazier, C.R. Abernathy, S. J. Pearton, J. S. Lee, Y. D. Park, Z. G. Khim, J. Kim, F. Ren, Appl. Phys. Lett. 80, 3964 (2002).