Kinetic roughening in polymer film growth by vapor deposition

The growth front roughness of linear poly( p-xylylene) films grown by vapor deposition polymerization has been investigated using atomic force microscopy. The interface width w increases as a power law of film thickness d, w similar to d(beta), with beta = 0.25 +/- 0.03, and the lateral correlation length xi grows as xi similar to d(1/z). with 1/z = 0.31 +/- 0.02. This novel scaling behavior is interpreted as the result of monomer bulk diffusion, and belongs to a new universality class that has not been discussed previously.