Ultrathin fluoropolymer films were prepared by depositing poly [2-(perfluorooctyl)ethyl acrylate] (PFOEA) on 12.5 cm diameter silicon wafer substrates using high-pressure free meniscus coating (hFMC) with liquid CO2 (1-CO2) as a coating solvent. Dry film thickness across the wafer substrate and the morphology of deposited films were characterized as a function of coating conditions-withdrawal velocities, solution concentrations and evaporation driving forces (Delta P). Thickness measurements by ellipsometry revealed that at zero or low evaporation driving forces (Delta P = 0-0.0138 MPa), highly uniform films with thicknesses in the range of 7-30 nrn were deposited over the entire concentration range (1-7 wt.%). However, films deposited at high evaporation driving forces (Delta P = 0.0414-0.0552 MPa) or larger concentrations (5-7 wt.%) with a AP of 0.0276 MPa were thicker (35-70 nm) and less uniform. Optical microscopy and atomic force microscopy (AFM) were used to characterize film morphology including drying defects and film roughness. Films deposited at zero or low Delta P of 0.0 138 MPa and low concentrations of 1-3 wt.% exhibited few drying defects and a low root mean square (RMS) roughness (similar to 2 nm). At higher evaporation driving forces and higher concentrations, ring-like drying defects were observed with diameters ranging 5-30 mu m. The film thickness and morphology of PFOEA films deposited from I-CO2 hFMC were compared to those deposited from 1, 1,2-trichlorotrifluoroethane (Freon 113) by normal atmospheric dip coating. Films deposited from 1-CO2 hFMC were much thinner and more uniform, and exhibit much fewer drying defects and lower RMS roughness. (c) 2007 Published by Elsevier B.V.