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

Abstract

The impact of Ti sputter target denitridation on the crystallographic orientation of single Ti layers and Ti/TiN/Al layer stacks was studied for three different underlayers: tetraethyl orthosilicate (TEOS)-based chemical vapor deposition (CVD) oxide, silane-based high-density plasma (HDP) CVD oxide, and thermal oxide. A clear correlation was found between Ti crystal orientation and Ti sputter target conditioning as well as oxide underlayer. The Ti crystal orientation determines the orientation of the Al in the Ti/TiN/Al layer stacks. The most perfect Al(111) orientation in Ti/TiN/Al layer stacks was found for a Ti layer sputtered on TEOS oxide after a Ti target denitridation of more than 5 s.