Novel multilayer ultrathin films of PR-SDS-PC were fabricated by employing the complex of phenolic resin (PR) and sodium dodecyl sulfate (SDS) as a "complex polyanion" and various polycations (PCs). The resulting films were etched quickly when being immersed in polar organic solvents due to the weak hydrophobic interaction between PR and SDS. By employing the photosensitive diazo resin (DR) as PC, the stability of the PR-SDS-DR film increases significantly after UV irradiation, because a covalent crosslinking structure forms in the film.