Hydrogen plasma pretreatment effect on the deposition of aluminum thin films from metalorganic chemical vapor deposition using dimethylethylamine alane

To study the effect of pretreatment of substrates on the deposition behavio r of Al thin films, the surfaces of TiN and SiO2 substrates were exposed to hydrogen plasma or Ar plasma before Al deposition. The Al films were depos ited by the pyrolysis of dimethylethylamine alane (DMEAA). A uniform Al fil m was deposited by the hydrogen plasma exposure to a SiO2 substrate, while island grains were grown by the Ar plasma exposure. The pretreatments of a TiN substrate did not affect the deposition rate of the Al film. The concen tration of OH radicals at the SiO2 surface was increased by the hydrogen pl asma treatment. We suggest a model in which OH radicals enhance the adsorpt ion of DMEAA on a SiO2 surface, resulting in a larger number of nucleation sites. (C) 1999 American Vacuum Society. [S0734-2101(99)04003-8].