VUV photoionization of Si(CH3)2Cl2 using synchrotron radiation

The complicated dissociative photoionization of Si(CH3)2Cl2 has been investigated with photoionization mass spectrometry (PIMS) and a synchrotron as source of vacuum ultraviolet (VUV) radiation. We determined appearance energies (AE) of the parent cation Si ( CH 3 ) 2 Cl 2 + and various ionic fragments - Si ( CH 3 ) 2 Cl + , Si ( CH 3 ) Cl 2 + , Si ( CH 3 ) Cl + , etc. – originating from photofragmentation. The appearance energy of Si ( CH 3 ) 2 Cl 2 + is 10.41 eV, in agreement with measurements of the photoelectron spectrum. Relative photoexcitation spectra of individual fragment ion yields are obtained and the dissociative processes are discussed. A comparison of Si(CH3)2Cl2 and Si(CH3)Cl3 provides insight and understanding of fragmentation processes on dissociative photoionization of gaseous chlorosilanes.