Low-temperature ion-induced epitaxial growth of α-FeSi2 and cubic FeSi2 in Si

Abstract
Ion‐beam‐induced epitaxial crystallization of amorphous Si implanted with Fe to 18 at. % peak concentration was studied. The structure of the specimen was characterized using transmission electron microscopy and Rutherford backscattering spectrometry. Both cubic FeSi2 and α‐FeSi2 were formed in epitaxy with the Si matrix with two types of orientations (fully aligned and twinned). The twins of α‐FeSi2 and those of cubic FeSi2 were found to have exactly the same type of epitaxial relationship as for the aligned ones. The thermodynamically stable β‐FeSi2 is not formed, demonstrating that ion‐beam‐induced crystallization can lead to preferential phase formation as well as to epitaxy.