Thin Solid Films, Vol.388, No.1-2, 101-106, 2001
NbAl3/Al microlaminated thin films deposited by UV laser ablation
NbAl3/Al microlaminated multilayer thin films were obtained by a laser ablation deposition method, using a KrF excimer laser (lambda = 248 nm) at a fluence of 7.6 J/cm(2). Films were deposited on Si substrates cooled during deposition by liquid nitrogen flow in order to minimize crystal growth and interdiffusion between NbAl3 and Al layers. A helium gas flow to the middle portion of substrate and target was maintained at varying ambient pressure conditions (0, 100, 200 mtorr). Microstructures of the films produced were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM). With no helium backpressure, films exhibited an amorphous structure, but with increasing He pressure, the crystallinity of the films increased. TEM investigations determined the average aluminum crystal size to be approximately 30 nm, and each layer thickness to be 80 nm. STEM/EDS (electron dispersive spectroscopy) analysis showed no significant interdiffusion between NbAl3 and Al layers.