AVS 51st International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP27
Comparison of the Agglomeration Behavior of Thin Metallic Films on SiO@sub 2@

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: P.R. Gadkari, University of Central Florida
Authors: P.R. Gadkari, University of Central Florida
A.P. Warren, University of Central Florida
R.M. Todi, University of Central Florida
T. Cubano-Cruz, University of Central Florida
K.R. Coffey, University of Central Florida
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The preparation of continuous thin films of metals on insulating oxide surfaces is of interest to applications, such as semiconductor interconnections, as well as fundamental studies of transport in thin films. Noble and near-noble metals tend not to wet amorphous oxide surfaces and thus the equilibrium shape for the deposited metal is an isolated island on the substrate surface. For sufficiently thick films and/or reduced surface mobility, continuous metallic films can be formed by non-equilibrium processing. However, the geometry of such films is unstable, and upon annealing they can agglomerate and again form isolated islands on substrate surface. In this work we report the study of the formation of voids and agglomeration of initially continuous Ru, Pt, Cu and Au thin films deposited on amorphous thermally grown SiO@sub 2@ surfaces. Polycrystalline thin films having thicknesses in the range of 5nm to 100nm were UHV sputter deposited on thermally grown SiO@sub 2@ surfaces. The films were annealed at temperatures in the range of 150°C to 800°C in argon and argon+3% hydrogen gases. Scanning electron microscopy was used to investigate the agglomeration behavior and transmission electron microscopy was used to characterize the microstructure of the as-deposited and annealed films. The agglomeration of Ru and Cu films was observed to follow a grain boundary grooving process, whereas fractal growth of voids was observed in Pt and Au films. It is also observed that the tendency for agglomeration can be reduced by encapsulating the metal film with an oxide overlayer. Lastly, the variation of agglomeration with annealing temperature, gas ambient and film thickness is described.