DEPOSITION OF OXIDE LAYERS BY COMPUTER-CONTROLLED INJECTION-LPCVD

A new process for stable generation of precursor's vapour pressure for CVD thin layers synthesis is experimented. The vapour pressure is controlled by sequential computer-driven injection of precise micro amounts of liquid in an evaporator, where flash volatilization occurs. During deposition, the precursors are maintained at room temperature under inert gases in an hermetically closed vessel : even thermally unstable precursors may be used. The results reported here are focused on the OMCVD deposition of Ta2O5. The growth rate increases up to 11 mu m/h at 650 degrees C (amorphous layers), and decreases above (crystallized layers). In a second part, we demonstrate the feasibility of Ta2O5/SiO2 multilayers using two injectors.