Films which had been synthesized by reactively sputtering TiSi2, Ti5Si3 or Ti3Si targets in gaseous Ar/N2 mixtures were tested as diffusion barriers between planar (100) Si substrates, shallow n+p diodes, and Al or Cu overlayers. It was noted that the stability of the barriers usually improved with increasing N concentration in the films. It was found that Ti34Si23N43, sputtered from Ti5Si3, was the most effective diffusion barrier among all of the films that were studied. It was an excellent barrier between Si and Cu. A film that was about 100nm thick maintained the stability, of junction diodes with a 400nm Cu over-layer, for 0.5h (at up to 850C) during vacuum annealing. When it was used between Al and Si, the limit of stability that could be achieved with a 100nm-thick film was 550C. Heat treatment at 600C caused severe intermixing of the layers.

X.Sun, J.S.Reid, E.Kolawa, M.A.Nicolet, R.P.Ruiz: Journal of Applied Physics, 1997, 81[2], 664-71