Uniform, large-area TiO/sub 2/ thin films are formed by reactive sputtering deposition in an electron cyclotron resonance (ECR) sheet plasma. The plasma source consists of a pair of long permanent magnets and a slot antenna. The antenna is set up between magnets whose N poles face each other. The generated plasma are uniform in one direction. To make the thin-films uniform in large area, two triangular targets are adopted and substrates are turned at two different angles with respect to the targets. The target form and substrate angle are determined by simulation and experiment. The thin-films are characterized with a profilometer and an X-ray diffractometer. The films of TiO/sub 2/, especially rutile having high refractive index, are useful for optical coating. The generated films are of anatase that has refractive index of 2.5. Crystallization is improved by controlling the electric potential of the substrates and by annealing as well.