Crystallization of sputter deposited amorphous metal thin films

Au overlayers on W-Si can reduce the crystallization temperatures by 100(0)C. In this paper we report on further work done on the W-Si system. Using Differential Thermal Analysis (DTA) we have measured the crystallization temperature versus composition from approximately 5 at. % Si to 40 at. % Si. Additional overlayers of W, Cu, and Al have been investigated. Both the W and Cu overlayers appear to have little effect on the stability of the underlying W-Si, while the Al reduces the crystallization temperature by at least 100(0)C. These results reinforce the observation that the choice of overlayer plays a critical role in determining the overall stability of the metallization, and indicate that W-Si is a viable candidate for diffusion barriers on silicon.