Growth characteristics and electrical properties of Ta2O5 grown by thermal and O3-based atomic layer deposition on TiN substrates for metal-insulator-metal capacitor applications

We compared the suitability of tantalum pentoxide (Ta2O5) films produced via thermal and ozone based atomic layer deposition (Th-ALD and O3-ALD, respectively) using pentaethoxytantalum (PET) as a Ta precursor for use as a capacitor insulator in metal-insulator-metal configurations. H2O and O3 were used as reactants for Th-ALD and O3-ALD Ta2O5, respectively. Both of the processes exhibited ALD mode growth with good self-saturation behavior and produced pure Ta2O5 films. However, O3-ALD Ta2O5 films showed higher growth rates (1.1 Å/cycle), density (7.85 g/cm3) and dielectric constant values (~ 46) compared to those of Th-ALD Ta2O5 (0.9 Å/cycle, 7.3 g/cm3 and ~ 40, respectively).