I'd was deposited onto Si (1 1 1) 7 x 7 surface at about 700 K inside in ultrahigh vacuum transmission electron microscope. In reflection electron microscopy (REM) observation of Pd-deposition process. it was indicated that Pd silicide islands were formed by involving two kinds of growth behavior. It was found from plan view transmission electron microscopy (TEM) that the islands have two kinds of shape, one round and the other rectangular (one-dimensional). Comprehensive TEM/REM and diffraction analysis revealed that the two kinds of the Pd silicide islands with different shape and atomic Structure grew independently. (C) 2002 Elsevier Science B.V. All rights reserved.