Dissociative double ionization following valence and Si:2p core level photoexcitation of SiCl₄ in the range 38-133 eV

The photoionization of SiCl₄ has been investigated in the valence and Si:2p inner-shell region using time-of-flight mass spectrometry and synchrotron radiation in the range 38-133 eV. Ion yields and branching ratios are reported for charged species arising from the dissociative photoionization processes. Various monocations such as Cl⁺, Cl₂⁺, and SiCl_n⁺ (n = 0-4) are observed together with doubly charged species such as Si²⁺, Cl²⁺, and SiCl²⁺. The photoion-photoion coincidence (PIPICO) technique has been employed to investigate a variety of dissociation processes via Coulomb explosion and to elucidate the dissociation mechanisms. Ion pairs of Si⁺ + Cl⁺ and SiCl⁺ + Cl⁺ are observed dominantly in the Si:2p edge. Variation of the ionic fragmentation as a function of photon energy is discussed in conjunction with the relevant electronic states.