Low temperature MOCVD of Ta2O5 dielectric thin films from Ta[NC(CH3)3][OC(CH3)3]3 and O2

摘要

Ta₂O₅ thin films were deposited at 155–400°C on amorphous SiO₂ and Pt/TiO _x /SiO₂/Si substrates by metal organic chemical vapor deposition (MOCVD) from tri( tert -butoxy)(isopropylimido)tantalum [Ta[NCH(CH₃)₂][OC(CH₃)₃]₃]–O₂, tri( tert -butoxy)(tert-butylimido)tantalum [Ta[NC(CH₃)₃][OC(CH₃)₃]₃]–O₂ and pentaethoxy tantalum [Ta(OC₂H₅)₅]–O₂ systems. Temperature dependency of the deposition rate was almost the same for the films from Ta[NCH(CH₃)₂][OC(CH₃)₃]₃–O₂ and Ta[NC(CH₃)₃][OC(CH₃)₃]₃–O₂ systems irrespective of the kinds of substrates, and the deposition rate of these two systems was higher than that of Ta(OC₂H₅)₅–O₂ system for all deposition temperature range within the present study. Dielectric properties of Ta₂O₅ thin films deposited on Pt/TiO _x /SiO₂/Si substrates at 200°C from Ta[NC(CH₃)₃][OC(CH₃)₃]₃–O₂ system and at 300°C from Ta(OC₂H₅)₅–O₂ system were also investigated. In spite of their 100°C lower deposition temperature, the Ta₂O₅ films from Ta[NC(CH₃)₃][OC(CH₃)₃]₃–O₂ system showed lower leakage current density and almost the same dielectric constant with those from Ta(OC₂H₅)₅–O₂ system.