Formation of the structure of thin layers deposited from the gas phase occurs not only during film deposition but also during the subsequent annealing. In the present work, porous films were deposited using the catalytic chemical vapor deposition (Cat-CVD) procedure. It was shown that the kinetics of a decrease in the film volume during annealing can be explained taking into account the role of Laplace pressure in the formed pores. (c) 2006 Elsevier B.V. All rights reserved.