Fluorine-doped tin oxide (FTO) films have been deposited by pulsed DC magnetron sputtering with an Sn target. Various ratios of ${\mathrm{CF}}_4/{\mathrm{O}}_2$ gas were injected to enhance the optical and electrical properties of the films. The extinction coefficient was lower than $1.5\times {10}^{-3}$ in the range from 400 to $800\mathrm{nm}$ when the ${\mathrm{CF}}_4/{\mathrm{O}}_2$ ratio was 0.375. The resistivity of fluorine-doped ${\mathrm{SnO}}_2$ films ( $1.63\times {10}^{-3}\mathrm{\Omega }\mathrm{cm}$ ) deposited at $300°\mathrm{C}$ was 27.9 times smaller than that of undoped ${\mathrm{SnO}}_2$ ( $4.55\times {10}^{-2}\mathrm{\Omega }\mathrm{cm}$ ). Finally, an FTO film was consecutively deposited for protecting the oxidation of indium tin oxide films. The resistivity of the double-layered film was $2.68\times {10}^{-4}\mathrm{\Omega }\mathrm{cm}$ , which increased by less than 39% at a $450°\mathrm{C}$ annealing temperature for $1\mathrm{h}$ in air.