STRUCTURE AND ELECTRIC PROPERTIES OF TIO2 FILMS PREPARED BY COLD-PLASMA TORCH UNDER ATMOSPHERIC-PRESSURE

A torch-like plasma generator we developed to make low temperature mat erial processing possible in open air conditions was employed for the deposition of TiO2 films on substrates exposed to air. Ti(OEt)(4) or T i(O-iPr)(4) vapor was fed into the plasma generated in an insulator no zzle lining the inner surface of a grounded cylindrical anode and cont aining a metal needle cathode at the center. The homogeneous plasma wi th T-e of 1.8 eV and T-g of 200 degrees C, respectively, could decompo se Ti(OR)(4) to flush decomposition species onto a substrate placed in air. The film thus prepared was stoichiometric and amorphous TiO2, bu t contained short-range crystallinity. The phase structure of the film s changed by the admiring of hydrogen in the plasma. The TiO2 film dep osited from a TEOT/H-2 mixture had a high breakdown electric field (1. 2 MV cm(-1)) as well as a high dielectric constant(epsilon=54) even in amorphous phase.