Solid Phase Epitaxy of Ferromagnetic MnAs Layer and Quantum Dots on Annealed GaMnAs

J. Sadowskia,b, J. Kanskic, M. Adellc, J.Z. Domagała a, E. Janik a, E. Łusakowska a, R. Brucasc and M. Hanson c aInstitute of Physics, Polish Academy of Sciences, al. Lotników 32/46, 02-668 Warsaw, Poland bInstitut für Angewandte und Experimentalle Physik, Universität Regensburg, 93040 Regensburg, Germany cDepartment of Applied Physics, Chalmers University of Technology, 41296 Göteborg, Sweden

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Received: 4 06 2005;

We show that post growth annealing of GaMnAs under As capping at temperatures in the range of 180-210 ºC leads to significant surface modifications. Depending on GaMnAs layer thickness and composition, we obtain either a smooth continuous reacted (MnAs) surface layer or 3D islands (quantum dots). The surface modifications are due to a solid phase epitaxial process, in which Mn interstitials diffusing to the GaMnAs surface are bound with the As.

DOI: 10.12693/APhysPolA.108.851 PACS numbers:81.10.Jt, 81.15.Hi, 68.65.Hb, 68.37.Ps