화학공학소재연구정보센터
Journal of Crystal Growth, Vol.267, No.1-2, 231-238, 2004
Structure characterization of Fe films grown on GaAs (100) by ion-beam sputter epitaxy
Fe (1 0 0) films, 25 nm thick, were epitaxially grown by ion-beam sputtering (IBS) at 300degreesC on monocristalline GaAs (1 0 0) surfaces. Good quality epitaxy was inferred from X-ray diffraction and transmission electron microscopy (TEM) measurements. The rocking curve width obtained from the Fe (2 0 0) peak compares well with that of samples prepared by molecular beam epitaxy (MBE). TEM observations showed that the Fe films contained accommodation dislocations and that no significant interdiffusion took place. After 1 h annealing at 400degreesC, the solid-state reaction at the interface mainly resulted in the formation of Fe2As and Fe3Ga2-xAsx compounds, in agreement with the phase-diagrams. The iron-arsenide grains grow into the substrate below the Fe/GaAs interface, and present trapezoidal shapes with rounded angles. Analyses on their morphology and size, as well as on the orientation relationships between Fe,As and GaAs phases, were also carried out. The results obtained in the present study provide motivation to pursue the fabrication of Fe/GaAs (1 0 0) heterostructures using the IBS technique to draw a parallel with the M BE one. (C) 2004 Elsevier B.V. All rights reserved.