Surface properties of electrodeposited a-Si:C:H:F thin films by x-ray photoelectron spectroscopy

Abstract

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 photoelectron spectra exhibited binding-energy shifts corresponding to SiFx (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 close agreement with the measured values. The relative concentration values 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 spectroscopy and scanning electron microscopy data.