Effects of insulator surface roughness on aluminium-alloy film crystallographic orientation in aluminium-alloy/titanium/insulator structure

Effects of insulator surface roughness on the overlying Al-alloy film crystallographic orientation in Al alloy/Ti/insulator layered structures have been studied. Tetra-ethyl-ortho-silicate-O sub 3 (TEOS-O sub 3 ) based SiO sub 2 and its chemical-mechanical-polished (CMP) films have been used in order to change the surface roughness of underlying insulators. Ti(002) and (011) peak intensities in XRD spectra increase when the underlying insulator has a smooth surface, and this orientation change in Ti causes Al(111) peak intensity more than two orders higher on a very smooth surface of TMP TEOS-O sub 3 SiO sub 2 film, particularly in Al high temperature sputtering, compared to that on non-CMP TEOS-O sub 3 SiO sub 2 film. This crystallographic orientation change results in a large difference in the electromigration performance in high temperature sputtered Al alloy/Ti layered metal line.