UV LASER-INDUCED CHEMISTRY OF ADSORBED DIMETHYLCADMIUM

The UV laser chemistry of dimethylcadmium (DMCd) either chemisorbed at 297 K on n-type Si(100) with native oxide or physisorbed at 150 K on a photodeposited cadmium film has been studied by using mass spectrometry of desorbed species. A XeCl laser induced the heterogeneous fragmentation of these chemisorbed molecules as well as the desorption of DMCd, Cd, and CH3. The resonant absorption of a KrCl laser radiation by adsorbed DMCd led to their photolysis and the ejection of DMCd and its fragments in both neutral and ionic forms. The kinetic, laser fluence, and time-of-flight dependences of desorbed species have been measured to elucidate the mechanisms of the dissociative and desorption processes either induced by lasers or occurring spontaneously. The effects of these lasers on chemisorbed DMCd as well as KrCl laser assisted processes in chemisorbed and physisorbed molecules have been compared.