State-specific enhancement of Cl+ and Cl- desorption for SiCl4 adsorbed ona Si(100) surface following Cl 2p and Si 2p core-level excitations

State-specific desorption for SiCl4 adsorbed on a Si(100) surface at simila r to 90 K with variable coverage following the Cl 2p and Si 2p core-level e xcitations has been investigated using synchrotron radiation. The Cl+ yield s show a significant enhancement following the Cl 2p --> 8a(1)* excitation. The Cl- yields are notably enhanced at the 8a(1)* resonance at both Cl 2p and Si 2p edges. The enhancement of the Cl yield occurs through the formati on of highly excited states of the adsorbed molecules. These results provid e some new dissociation processes from adsorbates on surfaces via core-leve l excitation.