AVS 50th International Symposium
    Semiconductors Thursday Sessions
       Session SC+MI-ThA

Paper SC+MI-ThA9
Growth of (Ga,Mn)N: a Diluted Magnetic Semiconductor by Chemical Beam Epitaxy (CBE)

Thursday, November 6, 2003, 4:40 pm, Room 321/322

Session: Ferromagnetic and Dilute Magnetic Semiconductors
Presenter: A. Carreno, The University of Houston
Authors: A. Carreno, The University of Houston
C. Boney, The University of Houston
A. Bensaoula, The University of Houston
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The GaN material system is a very promising candidate for the realization of electronic devices based on dilute magnetic semiconductor (DMS) films. The incentive behind DMS materials is the potential to form high-density magnetic memory integrated ICs, semiconductor-based magnetic sensors, magneto-optical devices for communications systems, and other spin-based and photonic-based applications. Many reports have indicated that high doping levels of Mn in GaN lead to ferromagnetic materials with Curie temperatures at or above room temperature. To date (Ga,Mn)N has been fabricated by several epitaxial and non-epitaxial techniques. However, to our knowledge, we are the first to report the epitaxial growth of (Ga,Mn)N by CBE. (Ga,Mn)N has been grown on sapphire substrates using TEG, NH3, and solid Mn as precursors. Very smooth GaMnN films exhibiting bright 2D RHEED patterns have been obtained with Mn concentrations between 0.5-2.0% as determined by EPMA and XPS. XPS depth profiling verifies that the Mn is of uniform concentration throughout the films. In addition to RHEED, the CBE chamber employs two Time of Flight Ion Scattering Spectroscopy techniques, Direct Recoil Spectroscopy (DRS) and Mass Spectroscopy of Recoiled Ions (MSRI). These TOF techniques are used as an in-situ, real time analytical process which allows the surface composition information of film components and impurities to be determined as well as analyzing the structural characteristics based on changes in the relative signal levels with azimuthal rotation of the sample. In these ways DRS/MSRI has been used to detect the incorporation of Mn into the GaN matrix during film growth and from azimuthal data extract the surface periodicity which allows construction of surface structure models for GaN and (Ga,Mn)N surfaces. In addition to available Raman and photoluminescence data, characterization of magnetic properties of the (Ga,Mn)N films is currently under way and will be reported.