SURFACE-PROPERTIES OF ELECTRODEPOSITED A-SI-C-H-F THIN-FILMS BY X-RAYPHOTOELECTRON-SPECTROSCOPY

Surface properties of amorphous silicon thin films containing hydrogen , flourine and carbon obtained from hydrofluosilicic acid and ethylene glycol using the electrodeposition method are reported as a function of current density and deposition time. The Si2p core level X-ray phot oelectron spectra exhibited binding-energy shifts corresponding to SiF x (x = 1-4), SiC, Si-H and Si-O-2 type bond formations. The shifts in 1s spectra of fluorine, carbon x and oxygen confirmed the presence of fluorine, carbon and oxygen in bonded form. Theoretical binding-energy shifts calculated from Pauling's electronegativity values were in clo se agreement with the measured values. The relative concentration valu es of C/Si estimated in these films were found to be larger than those of F/Si and O/Si. The results were corroborated with infrared spectro scopy and scanning electron microscopy data.