PROPERTIES OF FLUORINE-DOPED TIN OXIDE-FILMS PRODUCED BY ATMOSPHERIC-PRESSURE CHEMICAL VAPOR-DEPOSITION FROM TETRAMETHYLTIN, BROMOTRIFLUOROMETHANE AND OXYGEN

Fluorine-doped tin oxide films were produced by atmospheric pressure chemical vapor deposition from various mixtures of tetramethyltin, bromotrifluoromethane, and oxygen. Growth rates of up to 60 nm s-1 were achieved. Optical measurements to assess the visible transparency are presented. Hall effect measurements revealed mobilities of up to 42 cm2 V-1 s-1 and carrier concentrations typically in the range (1-6) x 10(20) cm-3. Microprobe analysis revealed the presence of electrically inactive fluorine atoms especially at low deposition temperatures and at high tetramethyltin (2 mol.%) and bromotrifluoromethane (4 mol.%) compositions. However, at high deposition temperature and low tetramethyltin (0.5 mol.%) or low bromotrifluoromethane (0.5 mol.%) mixtures, almost all the fluorine dopant atoms are electrically active. Scanning electron microscopy studies revealed an increase in surface texturing when the tetramethyltin concentration was decreased or the oxygen concentration was increased. X-ray crystallography showed preferential orientation of the crystallites for most reaction conditions.