The effects of high temperature deposition methods and underlayters on the evolution of Al film microstructures as Al grain size, preferred(III) orientation and morphology of Si preciptate were studied. Grain size of Al film depositied by two-step method has larger than that of Al film deposited by one-step method at $500^{circ}C$. The morphology of Si precipitate is directly linked with the preferred nucleation site for Si preciptation, dependent on the deposition temperature/method and underlayer type. At the deposition temperature of $300^{circ}C$, the preferred nucleation site is the interace for $SiO_2$ underlayer, but is the grain boundary edge for Ti/TiN and Ti/TiN/Ti underlayers.