LOW-TEMPERATURE ION-INDUCED EPITAXIAL-GROWTH OF ALPHA-FESI2 AND CUBICFESI2 IN SI

Ion-beam-induced epitaxial crystallization of amorphous Si implanted w ith Fe to 18 at. % peak concentration was studied. The structure of th e specimen was characterized using transmission electron microscopy an d Rutherford backscattering spectrometry. Both cubic FeSi2 and alpha-F eSi2 were formed in epitaxy with the Si matrix with two types of orien tations (fully aligned and twinned). The twins of alpha-FeSi2 and thos e of cubic FeSi2 were found to have exactly the same type of epitaxial relationship as for the aligned ones. The thermodynamically stable be ta-FeSi2 is not formed, demonstrating that ion-beam-induced crystalliz ation can lead to preferential phase formation as well as to epitaxy.