Deposition of transparent conductive tin oxide thin films doped with fluorine by PACVD

In this work an attempt has been made to dope the films by a one step process by introducing a fluorine precursor which was SF6 with the plasma mixture used for the deposition of tin oxide films. Optical emission spectroscopy and mass spectrometry were used to study the plasma phase and the characterization of the films was carried out by different diagnostic techniques such as SEM, XPS and FTIR. An increase of the electrical conductivity was obtained for very small flow rates of SF6 introduced in the discharge (from 95 to 130 S cm(-1)). For higher flow rates, a sharp decrease of the conductivity was observed. For such flow rates, competitive etching and functionalization processes, assisted by fluorine atoms present in the discharge, take place. Although the conductivity dropped down, the optical transmission of the deposited films remained higher than 90%. (C) 2002 Elsevier Science B.V. All rights reserved.