Growth behavior and structural characteristics of TiO2 thin films using (CpN)Ti(NMe2)(2) and oxygen remote plasma

Abstract

This study examined the effect of a novel precursor on the growth behavior and structure of titanium dioxide (TiO2) thin films. TiO2 thin films were deposited by remote plasma atomic layer deposition (RPALD). Dimethylamin-cyclopentadienyl titanium, (CpN) Ti(NMe2)(2), was used as a Ti precursor and oxygen plasma was used as a reactant. (CpN) Ti(NMe2)(2) is a newly synthesized precursor for TiO2 deposition. Characteristics of TiO2 thin films deposited by (CpN) Ti(NMe2)(2) were compared with those of films deposited using a titanium tetrakis isopropoxide (TTIP) precursor. A wide processing window from 170 to 400 degrees C was observed, and the growth rate was around 0.44 angstrom/cycle at 200 degrees C. X-ray photoelectron spectroscopy (XPS) measurements revealed that nearly stoichiometric TiO2 films were deposited. The residual impurity concentrations inside the films were almost the same for (CpN) Ti(NMe2)(2) and TTIP. TiO2 films deposited on ruthenium showed a pure rutile phase at a low deposition temperature and low power pre-treatment. Therefore, this TiO2 film is very promising for metal-insulator-metal (MIM) capacitor dielectrics for dynamic random access memory (DRAM) applications.