A versatile chemical vapor deposition (CVD) technique is proposed which has two noteworthy technical features : (1) alternate or intermittent introduction of source vapors followed by evacuation and (ii) one or more excitations synchronized with the sequence of vapor introduction. Since it can select and identify the place and time for the occurrence of reactions and excitation among source molecules, this technique also promises to be valuable in investigating the use of conventional CVD processes with unfamiliar materials. In this work, the technique is used to investigate the conventional photo and thermal CVD processes of tantalum pentoxide film using tantalum pentachloride and oxygen. The results indicate that significant deposition occurs even without the vapor phase reactions among source vapors and that photoexcitation of the substrate surface greatly enhances film deposition. In the course of the investigation, it was observed that temporary photoexcitation and ozone supply produced a high rate of film deposition even at temperatures lower than 300-degrees-C.