RADIO-FREQUENCY MAGNETRON SPUTTER-DEPOSITION OF CAF2 FILMS

Calcium fluoride films have been deposited onto unheated (<100 degrees C) substrates by low power rf magnetron sputtering of CaF2 targets us ing Ar and Ne process gases at pressures of 0.5-2.7 Pa, biased and flo ating substrate potentials, and various geometries of the substrate wi th respect to the source. The thickness and composition of the films a re very sensitive to resputtering of the growing film. Uniform and sto ichiometric films were most readily obtained on off-axis substrates us ing two sputter sources oriented with the targets facing each other. T he films were found to be crystalline, have a fine textured microstruc ture, and to be transparent and highly resistive. (C) 1998 American Va cuum Society.