Preparation and characterizationThin pinhole-free carbon films

Uniform pinhole-free carbon films were prepared on silicon wafers, oxidized silicon wafers, sapphire and Al2O3 by the in situ thermal decomposition of a phenol-formaldehyde resin. Homogeneous and reproducible film thickness, in the range from 0.3 to 1.5 μm, as well as complete coverage of surface features was achieved by spin coating the substrates with a solution of the resin. The electrical resistivities ranged from 2 × 10−2 to 2 × 10−3 Ω cm depending upon the upper limit of the pyrolysis temperature.