Roughness and texture correlation of Al films

Abstract

Titanium films prepared by standard direct-current (DC) magnetron physical vapor deposition (PVD) and ionized metal plasma PVD (I-PVD), with Al (0.5wt.%Cu) films on them, were studied. The surface roughness, reflectivity, and crystalline texture of Ti on SiO 2 /Si and Al on TiN/Ti/SiO 2 /Si were investigated with the same thickness of Al, TiN, and Ti. The surface roughness of Al films with Ti/TiN underlayers was found to be capable of monitoring Al (111) texture. So, the reflectivity of Al/TiN/Ti film stack can be used as a quick monitor for the electromigration (EM) lifetime.

Impact of Ti Sputter Target Denitridation on the Crystallographic Orientation of Single Ti Layers and Ti/TiN/AlCu Layer Stacks on Different Oxides

“…It was found that the MTTF of Al interconnects depends on the size and crystallographic orientation of the Al grains, where the (111) orientation gives the best results. 1,2 Therefore, a great deal of effort has been directed to obtain strongly (111) fibertextured Al films [3][4][5] ; for instance, Murray and Rodbell 6 studied the impact of oxide underlayers on the crystalline orientation of bare AlCu layers.…”