Nanoscale surface roughening in ultrathin aluminum films
MetadataShow full item record
We report studies of the formation of aluminum structures, with nanometer length scales, in ultrathin layers deposited on glass and analyzed using atomic force microscopy. Surface roughness, lateral cutoff length, and surface scaling exponent are all found to vary systematically with Al thickness. The initial nanocrystal formation is described by stress-energy minimization. We interpret the observed scaling behavior based on the kinetic theory of roughening. For very thin layers 50 nm the roughness is consistent with a 4h growth factor, where h is surface height. For thick layers 50 nm the 2 h 2 conserved mechanism is dominant. Substrate stress is not found to influence the scaling exponent through the kinetic theory.