IRON SILICIDE GROWTH ON SI(111) SUBSTRATE USING THE METALORGANIC VAPOR-PHASE EPITAXY PROCESS

Iron silicide thin films (epsilon-FeSi, alpha-FeSi2 and beta-FeSi2) were grown on silicon (111) substrates using the metalorganic vapour phase epitaxy (MOVPE) process with iron pentacarbonyl (Fe(CO)(5)) and disilane (Si2H6) precursors. Attention was mainly paid to the beta-FeSi2 phase. Transmission electron microscopy (TEM) and X-ray diffraction measurements allowed optimization of the growth process and revealed the nature and structure of the layers grown on the silicon substrate. A growth model is discussed and the action of the thermal annealing, which leads to the coalescence of the dendrites to form a continuous film of beta-FeSi2 up to about 1000 Angstrom thick, is described. Finally a photoluminescence signal has been detected in the range of the expected direct band gap value of beta-FeSi2.