Microstructural development of dispersion strengthened cu thin films

摘要

The internal oxidation method is applied for the first time to produce a fine dispersion of second phase particles in thin films. A processing route is presented which includes ultra-high vacuum magnetron sputtering of about 1 mu m thick alloy films onto Si substrates followed by insitu annealing and oxidation. Two different Cu-base alows are examined, Cu-Y and Cu-Al, in which the extent of miscibilitiy differs significantly. This has considerable influence on the grain growth behavior. Nanoindention and wafer-curvature experiments show a drastic improvement of both room-temperature and high-temperature strength. Phenomena well known from bulk oxide-dispersion strengthened (ODS) alloys are found to appear in the thin films as well: Results on abnormal grain growth and the formation of creep voids are presented and discussed in terms of particle effects.