Statistical parameters for rough surfaces of thin films of CaF(2) and Ag/CaF(2).

Statistical parameters, rms roughness delta and autocovariance length sigma, are determined both for rough surfaces of CaF(2) deposits and for surfaces of silver films deposited on these CaF(2) underlayers. The dependence of delta and sigma on the CaF(2) film thickness d is investigated. It is shown that the silver films do not replicate well the CaF(2) underlayers. A review of the relationships between delta, sigma and d when seeking control of the roughness of a silver film by controlling d is proposed. It is also shown that CaF(2) is a good underlayer compared with LiF.