DEPTH, PHASE AND COARSENING EVOLUTION OF FESI2 PRECIPITATES UPON THERMAL ANNEALING

gamma-FeSi2 precipitates were produced in Si(001) wafers by an ion bea m induced epitaxial crystallization process and subsequently annealed at temperatures in the range 700-900 degrees C. The resulting Fe redis tribution, phase transition and precipitate coarsening were studied us ing Rutherford backscattering, channeling and transmission electron mi croscopy techniques. It is shown that a gamma to beta phase transition starts at 700 degrees C and it almost completed at 900 degrees C. Thi s is accompanied by an Fe redistribution and a coarsening process. The extracted activation energy for the coarsening process Q = 3.5 +/- 0. 3 eV is in excellent agreement with theoretical estimations assuming O stwald ripening process.