Si₂Cl₆ and Si₂H₆ adsorption on CaF₂/Si(111)

Adsorption of Si₂Cl₆ and Si₂H₆ on epitaxially grown CaF₂/Si(111) was investigated by core level and valence band photoemission. CaF₂ surfaces that were first photoactivated with intense synchrotron radiation showed enhanced molecular adsorption indicating that patterned deposition of silicon may occur. Attempts to chemical vapor deposit Si with these molecular precursors under elevated temperatures revealed that Si₂H₆ was able to sustain Si growth on the CaF₂ epitaxy, while Si₂Cl₆ adsorption terminated after ∼1 monolayer of deposition. Possible explanations for this behavior are presented.