Novel Highly Volatile MOCVD Precursors for Ta2O5 and Nb2O5 Thin Films

Novel Ta and Nb compounds Ta(NtBu)(OtBu)3 (1) and Nb(NtBu)(OtBu)3 (2) were prepared as volatile liquid precursors for the MOCVD process. Ta2O5 and Nb2O5 films were obtained by using 1 and 2 in a lower temperature regime than pentaethoxy tantalum (PET) and pentaethoxy niobium (PEN). The deposition rates of 1 and 2 were higher more than 10 times than PET and PEN. Both precursors 1 and 2 gave conformal metal-oxide films, which exhibit excellent step coverage of over 90% on SiO2 holes with an aspect ratio of ca. 6.