The described embodiments of methods of bottom-up metal deposition to fill interconnect and replacement gate structures enable gap-filling of fine features with high aspect ratios without voids and provide metal films with good film quality. In-situ pretreatment of metal film(s) deposited by gas cluster ion beam (GCIB) allows removal of surface impurities and surface oxide to improve adhesion between an underlying layer with the deposited metal film(s). Metal films deposited by photo-induced chemical vapor deposition (PI-CVD) using high energy of low-frequency light source(s) at relatively low temperature exhibit liquid-like nature, which allows the metal films to fill fine feature from bottom up. The post deposition annealing of metal film(s) deposited by PI-CVD densifies the metal film(s) and removes residual gaseous species from the metal film(s). For advanced manufacturing, such bottom-up metal deposition methods address the challenges of gap-filling of fine features with high aspect ratios.