Study of high conductivity binary Ag-W layers for application in multilevel interconnection

In this paper are presented the results of the study of Ag-W thin films deposited by ion beam sputtering (IBS) and electroless (El) technology on SiO₂/Si substrates for MOS (Ag-W/SiO₂/Si) capacitors. This is the first application of the Ag-W films for metallization and interconnects in microelectronics. From the C-V characteristics of capacitors, measured as deposited and annealed at temperatures up to 475°C, has resulted that Ag-W films may maintain normal C-V shape and low failures (less that 30%) for annealing at T⟨400°C. The capacitors exhibited almost ideal C-V high frequency characteristics and flat band voltage near to zero. Using the Zerbst model and C-t characteristics of capacitors were obtained the values of lifetime (τ) and velocity of recombination (s). The generation lifetime and the recombination surface velocity were of the same order of those for similar structures with Cu, Co and Al metallization. Those results indicate that Ag-W layers are MOS technology compatible and can be used in microelectronics as a new interconnect and metallization material