Poly(methyl silsesquioxane) (PMSSQ) thin films with micropatterned surface structures have been prepared by use of adamantylphenol molecules as a photo-thermal sensitive moiety together with UV lithographic technique and mild heating process. Initially, PMSSQ films form positive patterns of micronscale due to the film densification triggered by photooxidation and photopolymerization of doped moieties within UV exposed region. With thermal treatment, negative patterns from these pre-patterned films are formed by the difference of polycondensation rates between non-exposed regions and irradiated areas without additional developing or etching steps. This structural transformation of PMSSQ thin films was investigated using Fourier-transformed infrared spectroscopy, ultraviolet visible spectroscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy, and field emission scanning electron microscopy. (c) 2006 Elsevier B.V. All rights reserved.