A method of forming a low temperature silicide film on a substrate includes supplying a source gas to a cluster formation chamber to form a gas cluster that is subsequently moved to an ionization-acceleration chamber to form a gas cluster ion beam (GCIB). The GCIB is injected into a processing chamber containing the substrate. A precursor gas is injected through an injection device located on a top portion of the processing chamber to form a silicide film on the substrate by bombarding the substrate with the GCIB in the presence of the precursor gas.