PATHWAYS AND INTERMEDIATES IN THE REACTION OF TETRAETHOXYSILANE ON SI(100)-2X1

The adsorption and reaction of tetraethoxysilane (TEOS) on Si(100)-2 X 1 surfaces was studied using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). TEOS adsorbs dissociatively on the Si(100)-2 X 1 surface via cleavage of the C-0 bonds in the ethoxy ligands forming a mixture of adsorbed di- and triethoxysiloxane and ethyl groups. The adsorbed ethoxysiloxane fragments decompose at temperatures between 300 and 450 K to produce SiO2 and ethyl groups. The surface ethyl groups undergo a complex reaction mechanism resulting in the production of ethylene at three separate temperatures during temperature programmed desorption experiments.