Thin films were reactively sputtered from M5Si3 and WSi2 targets. They were then evaluated, as diffusion barriers for the Al metallization of Si, by using electrical and electronic methods, back-scattering spectrometry, X-ray diffractometry, transmission electron microscopy, scanning electron microscopy, and secondary ion mass spectrometry. At their optimum compositions, the M-Si-N films prevented Al overlayers from electrically degrading shallow-junction diodes during 600s anneals at temperatures above the melting point of Al. Secondary ion mass spectrometry indicated that there was essentially no diffusion of Al into the M-Si-N films during heat treatment (700C, 10h). The stability could be partially attributed to a self-sealing 3nm-thick AlN layer which grew at the M-Si-N/Al interface.

J.S.Reid, E.Kolawa, C.M.Garland, M.A.Nicolet, F.Cardone, D.Gupta, R.P.Ruiz: Journal of Applied Physics, 1996, 79[2], 1109-15