Formation Condition of Abnormal Structures on Thin Mo Film

Abstract

Thin Mo films were prepared on tho cleaved surfaces of NaCl using the electron beam evaporation and two deposition parameters of substrate temperature and film thickness. Abnormal structures appearing on the Mo film were then investigated by transmission electron microscopy and electron diffraction.An amorphous Mo film was formed independent of the thickness of the film at substrate temperatures below 150°C, but nucleation was observed to take place above about 100°C. At high substrate temperatures, also, abnormal fcc and/or fcc+bcc structures in the Mo films were formed when the film thickness was below about 16.9nm. For film thicknesses above 16.9nm, all the deposited films had normal bcc structure for bulk Mo. Electron micrographs and electron diffraction patterns revealed that the Mo films, including fcc phase, had both microcrystallities and two dimensional growth layers growing epitaxially on the (100) surfaces of NaCl held at 400°C.