Boron surfactant enhanced solid-phase epitaxy (SPE) of thin Si films on CaF2/Si(111) substrates has been studied. Two different growth processes were investigated. In the first process, I NIL of boron atoms was predeposited on the CaF2 surface at room temperature before Si evaporation followed by an anneal to 635degreesC. This resulted in Si cluster formation. The surface morphology of the Si layer did not show any improvement compared to SPE without surfactant. In the second process, boron atoms were deposited directly on top of the amorphous Si film. This resulted in continuous and smooth epitaxial Si layers on CaF2 with a sharp B-induced (root3 x root3)R30degrees surface reconstruction after annealing. (C) 2004 American Vacuum Society.