Ohmic Contact of Cu/Mo and Cu/Ti Thin Layers on Multi-Crystalline Silicon Substrates

Cu-Mo and Cu-Ti contact structures were fabricated on multi-crystalline silicon substrates to provide a low resistance ohmic contact. Deposition steps are done in an excellent vacuum chamber by means of electron beam evaporation and samples are then annealed for the realization of an efficient alloy layer. The effects of process parameters such as film thickness, annealing duration and temperature on the contact quality have been investigated and optimized for achieving the best special contact resistivity. The specific contact resistance obtained for Cu-Mo and Cu-Ti structures were 8.58×10-6 Ω-cm2 and 9.72×10-6 Ω-cm2, respectively. Finally, between the two proposed structures a comparison has been made which is resulted in the selection of Cu-Mo contact as the better structure due to its less resistance and better adhesion to the substrate.