Synchronously Excited Discrete Chemical Vapor Deposition of Ta20s

A versatile chemical vapor deposition (CVD) technique is proposed wh ich has two noteworthy technical features: (i) alternate or intermittent introduction of source vapors fol lowed by evacuation and (if) one or more excitations synchro-nized 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 tanta lum pentoxide film using tanta lum pentachloride and oxygen. The results indicate that significant deposition occurs even without the vapor phase reactions among source vapors and that photoex-citation 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°C. Chemica l vapor deposition (CVD) consists of mix ing sev-eral kinds of source molecules in the vapor phase fol lowed by reacting and, in some cases, exciting them and finally growing a solid film on the substrate. A CVD process gener