SURFACE-ROUGHNESS SCALING OF PLASMA POLYMER-FILMS

Atomic force microscopy data reveal self-affine scaling of plasma polymer films. The rms surface roughness sigma increases with film thickness tau as sigma(f < xi-1) is similar to tau(beta), and with measurement length L as sigma(f > L-1 > xi-1) is similar to L(alpha), where xi is the surface roughness correlation length. At the deposition rate R = 2 mum/h, the scaling exponents alpha and beta are 0.9 and 0.7, both increasing to 1 at R = 1 mum/h. A competition between surface relaxation and deposition rate determine sigma and xi, which increase rapidly with R or inverse temperature.