IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electronics Wednesday Sessions
       Session EL+MI-WeM

Paper EL+MI-WeM5
Metalorganic Chemical Vapor Deposition of ZnO-based Diluted Magnetic Semiconductors

Wednesday, October 31, 2001, 9:40 am, Room 111

Session: Spintronics III: Ferromagnetic Semiconductors
Presenter: A.C. Tuan, University of Washington
Authors: A.C. Tuan, University of Washington
D. McCready, Pacific Northwest National Laboratory
S. Thevuthasan, Pacific Northwest National Laboratory
J.W. Rogers, Jr., Pacific Northwest National Laboratory
S.A. Chambers, Pacific Northwest National Laboratory
Correspondent: Click to Email
One of the most attractive means of adding the electron-spin degree of freedom to electronic and photonic devices is by spin injection and transport in semiconducting structures involving ferromagnetic metals or ferromagnetic dilute magnetic semiconductors (DMSs), as spin injectors. A great deal of work has been done in this area and thus far, DMSs have proven to be more efficient spin sources than ferromagnetic metals. This is because the conductivities of DMSs are better matched to those of the channel material. However, because of the very low ferromagnetic ordering temperature of current DMSs, efficient spin injection is only observed at cryogenic temperatures. A recent calculation predicts that heavily nitrogen-doped Mn@sub X@Zn@sub 1-X@O will exhibit a Curie temperature of ~320K,@footnote 1@ and serves as partial motivation for this work. We have grown Mn@sub X@Zn@sub 1-X@O films by metalorganic chemical vapor deposition (MOCVD), using a direct liquid injection system and @beta@-diketonate metal sources. Rutherford backscattering spectrometry (RBS) and X-ray photoelectron spectroscopy (XPS) show that compositions ranging from pure ZnO to ~Mn@sub 0.30@Zn@sub 0.70@O are achievable on Al@sub 2@O@sub 3@(0001) substrates, without carbon contamination. X-ray diffraction (XRD) was used to confirm that there was no phase segregation. XRD also indicated that all films grown below 500 °C had a preferred (0001) orientation, while epitaxy of ZnO was possible at 575 °C on both Al@sub 2@O@sub 3@ (0001) and ZnO(0001). Preliminary attempts at nitrogen incorporation show that NH@sub 3@ is a promising nitrogen source. @FootnoteText@ @footnote 1@T. Dietl, H. Ohno, F. Matsukura et al., "Zener model description of ferromagnetism in zinc-blende magnetic semiconductors," Science 287, 1019-22 (2000).