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

Abstract 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 A/cycle), density (7.85 g/cm3) and dielectric constant values (~ 46) compared to those of Th-ALD Ta2O5 (0.9 A/cycle, 7.3 g/cm3 and ~ 40, respectively).