  Al$_x$Sc$_{1-x}$ thin films have been studied with compositions around
Al$_3$Sc ($x$ = 0.75) for potential interconnect metallization applications.
As-deposited 25 nm thick films were x-ray amorphous but crystallized at
190{\deg}C, followed by recrystallization at 440{\deg}C. After annealing at
500{\deg}C, 24 nm thick stoichiometric Al$_3$Sc showed a resistivity of 12.6
$\mu\Omega$cm, limited by a combination of grain boundary and point defect
(disorder) scattering. Together with ab initio calculations that found a mean
free path of the charge carriers of 7 nm for stoichiometric Al$_3$Sc, these
results indicate that Al$_3$Sc bears promise for future interconnect
metallization schemes. Challenges remain in minimizing the formation of
secondary phases as well as in the control of the non-stoichiometric surface
oxidation and interfacial reactions with underlying dielectrics.
