Properties of atomic layer deposited (Ta1−xNbx)2O5 solid solution films and Ta2O5–Nb2O5 nanolaminates

( Ta 1−x Nb x ) 2 O 5 solid solution films and Ta2O5–Nb2O5 nanolaminates have been grown in an atomic layer deposition process at 300 and 325 °C. TaCl5 or Ta(OC2H5)5 and Nb(OC2H5)5 have been used as metal precursors while H2O has been applied as the oxygen source. Application of Ta(OC2H5)5 resulted in amorphous films with considerably better thickness uniformity than that characteristic of TaCl5-based process. Application of TaCl5 resulted in crystallized films. The high-field leakage current in (Ta1−xNbx)2O5 solid solution films with x=0.02–0.07 decreases by two to three orders of magnitude when compared to that of the nondoped Ta2O5. The permittivity of Ta2O5 films was 25 while the permittivity of amorphous or partially crystallized solid solution films and nanolaminates increased up to 33.