The UV‐induced photolysis of trimethyl(vinyloxy)silane (TMVSi) induced by ArF laser, affording a multitude of unsaturated hydrocarbons and a solid polydimethylsiloxane, represents a convenient process of chemical vapour deposition in which the silicon of the parent is almost completely utilized for the formation of the solid phase and in which the morphology and composition of the films is affected by the configuration of the substrate and laser beam. Copyright © 1999 John Wiley & Sons, Ltd.