Preparation of ZnF2 and ZnF2-BaF2 thin films by electron cyclotron resonance plasma-enhanced chemical vapor deposition

Crystalline and amorphous ZnF2 and ZnF2-BaF2 thin-films were prepared by el ectron cyclotron resonance plasma-enhanced chemical vapor deposition. The Z n and Ba beta-diketone chelates and an NF3 gas were used as starting materi als and a fluorinating gas, respectively. Crystalline and transparent ZnF2 thin-films were obtained on CaF2(111) substrates kept at 300 degrees C at t he deposition rates of 0.2-0.8 mu m/h. The thin film prepared at the 0.2 mu m/h deposition rate was oriented along a [110] direction. The ZnF2 thin-fi lm deposited on a substrate kept at 100 degrees C was amorphous though it t inted yellowish brown and had IR absorption bands due to contaminants. Colo rless and contaminant-free amorphous thin-films were obtained in a 60ZnF(2) .40BaF(2) composition. (C) 2000 Elsevier Science S.A. All rights reserved.