Selective growth of single-grain crystal in Al thin film by micron chevron-shaped laser beam scanning

Abstract

Polycrystalline Al film has been widely used in electronics and plasmonics, but the high density of grain boundaries causes conductivity deterioration, electromigration failure or incompatibility with fabrication of complex nano-circuits. In this letter, we propose an alternative approach to overcome the problems encountered with the use of polycrystalline Al film. Single-grain crystal of Al has been grown selectively in Al thin film by micron chevron-shaped laser beam scanning. The single-grain crystal, which is free of grain boundary, is of about 9-μm width and its length is comparable with the laser scan distance. A detailed investigation shows that the width of the single-grain crystal depends mainly on the laser power, whereas the crystal orientation depends on both the laser power and scan pattern. A wide-area of single-grain stripes can also be realized by a two-dimensional scan. The approach could be applicable to other metallic films, which are widely used in microelectronic and plasmonic devices.