MICROSTRUCTURE OF TIN FILMS AND INTERFACES FORMED BY ION-BEAM-ENHANCED DEPOSITION AND SIMPLE PHYSICAL VAPOR-DEPOSITION

The microstructure and composition of TiN films, formed by ion beam en hanced deposition (IBED) with different energy (40 keV and 90 keV) xen on ion bombardment and by simple physical vapor deposition (hereafter S-PVD) without any ion beam enhancement, and the interfaces between Ti N films and Si substrates have been studied by cross-sectional view an alytical electron microscopy in this work. Both the IBED TiN films pre pared by Xe+ bombardment with either 40 keV or 90 keV energy ions and the S-PVD TiN film consist of nanocrystals. The TEM observations in th e S-PVD case reveal an amorphous layer and a mixed layer of TiN grains and amorphous material at the TiN/Si interface. The thicknesses of th e amorphous layer and the mixed layer are about 210 nm and at least 40 nm, respectively. Upon 40 keV Xe+ bombardment, an amorphous Si transi tion layer of about 50 nm thickness is found at the TiN/Si interface, and the TiN grains close to the TiN/Si interface are of weak preferred orientation. Upon 90 keV Xe+ bombardment, amorphous TiN and Si layers are found with a total thickness of 80 nm at the TiN/Si interface, an d the TiN grains near the TiN/Si interface are of preferred orientatio n [111](TiN) parallel to [001](Si). The energy of xenon ion bombardmen t has a strong effect on the microstructural characteristics of TiN fi lms and the interfaces between the TiN films and the Si substrates, as well as the size and the preferred orientation of TiN grains.