Reliability of High Temperature Metallizations with Amorphous Ternary Diffusion Barriers

Thin rums of amorphous Ta-Si-N alloys were deposited by reactive sputtering of a Ta5Si3 target in an Ar/N2 ambient. These alloy films were tested as diffusion barriers between Al and Si, Cu and Si, as well as between Au and Si. Electrical measurements on shallow n⁺p junction diodes were used to evaluate the thermal stability of the Si/Ta36Si14N50(80 nm)/Al(500 nm), Si/Ta36Si14N50(80 nm)/Cu(500 nm)/Ta36Si14N50(30 nm) and Si/Ta36Si14N50(110 nm)/Au(280 nm) metallizations. Results of ongoing experiments indicate that after 1000 hrs annealing at 350°C in argon the Ta36Si14N50 amorphous films still maintain the integrity of the i I(V) characteristics of the shallow junction. The. surface morphology of the diodes is studied using scanning electron microscopy.