Site-specificity reduction during Auger decay following Si:2p photoionization in Cl3SiSi(CH3)3 vapor: An interatomic-Coulombic-decay-like process

Abstract

L23VV Auger decays caused by Si:2p core-level photoionization in Cl3SiSi(CH3)3 vapor have been studied by means of photoelectron Auger-electron coincidence spectroscopy. Upon the Si:2p photoionization, Cl3Si(CH2)nSi(CH3)3 (n = 0–2) shows two core-photoelectron emissions that are distinguishable by the silicon site. Cl3SiCH2CH2Si(CH3)3 (n = 2) and so forth, which have a long inter-site bridge, remember the initially core-ionized silicon-site and show site-specific fragmentation. In contrast, Cl3SiSi(CH3)3, which has direct SiSi bonding (n = 0), forgets the initially core-ionized silicon-site and shows negligible site-specificity in the final fragmentation stage. A reduction of the site specificity in Cl3SiSi(CH3)3 starts during a Si:L23VV Auger decay and its reduction process can be explained in terms of an interatomic-Coulombic-decay-like mechanism. Another site-specificity reduction, caused by inter-site energy randomization, occurs after every Si:L23VV Auger decay.