Laser Lateral Crystallization of Thin Au and Cu Films on SiO2

Abstract

Rapid lateral solidification via excimer laser melt processing is demonstrated in 200 nm thick pure Cu and Au films, encapsulated above and below by amorphous SiO2. Mask projection irradiation is used to selectively melt lines 3 to 30 m wide in the metal films, with lateral solidification proceeding transversely from the edge to the middle of the line. Encapsulation with the SiO2 overlayer and control of the fluence are found to be crucial parameters necessary to prevent dewetting while the films are molten. Transmission electron microscopy reveals large columnar grains with twin structures and other defects typical of rapid solidification.