Characterization of high-k HfO2 films prepared using chemically modified alkoxy-derived solutions

Abstract

The HfO2 films were prepared using alkoxy-derived precursor solutions. The effects of the chemical composition of precursor solutions on the microstructure development and electrical properties were investigated. The flatness and refractive index of the HfO2 films were improved by using diethanolamine-added solution. This result is considered to be due to the difference in the progress of organic decomposition and the behavior of nucleation and grain growth. The difference in the chemical composition affected the electrical properties such as leakage current and capacitance-voltage characteristics, which are related to the defects in the film and interface state.

Characterization of Sol-Gel-Derived and Crystallized HfO2, ZrO2, ZrO2-Y2O3 Thin Films on Si(001) Wafers with High Dielectric Constant

“…The SiO 2 film thickness was 2 nm, so the relative permittivity ε HfO2 was calibrated using that of SiO 2 . The relative permittivity was much higher than that of silicon dioxide (SiO 2 , 3.9), but is comparable to previously reported results (10~11) (Suzuki & Kato, 2009). The difference in the relative permittivity ε HfO2 between the sol-gel HfO 2 film and bulk HfO 2 may be due to the presence of the SiO 2 film and nanopores in the HfO 2 film.…”

Comparison oF Electrical Measurements with Structural Analysis oF Thin High-k Hafnium-based Films

“…As a matter of fact, if we repeat our calculations requiring that the calculated capacitance be equal to the measured one we deduce that ε HfO2 = 10 and ε HfSiOx = 9 for the samples with no nitridation. Similar values of dielectric constants were reported in the literature for very thin Hf-based films and are different from the bulk values (15). The situation is more complicated for the nitraded samples since the introduction of nitrogen in both the Hf-based films and the underlying oxide introduces a change of dielectric constant of both layers.…”

Photonic curing of sol–gel derived HfO2 dielectrics for organic field-effect transistors

“…In this work, four procedures showing the most promising approaches were evaluated to realize high quality inorganic dielectrics. The procedures mainly differ in the utilized precursors which are hafnium tetrachloride [30], hafnium ethoxide [31], hafnium pentanedionate [32] and hafnium isopropoxide [33]. The synthesis of the sol-gels was carried out as described in the respective publications and typically involved dissolving the precursor in a solvent followed by a reflux reaction at elevated temperatures to promote hydrolysis and polycondensation reactions.…”

“…The HfO 2 sol-gel solutions were prepared by the previously described methods [30][31][32][33]. Hafnium tetrachloride (HfCl 4 )-based sol-gels were prepared by dissolving HfCl 4 in 99.5% ethanol (EtOH) in an argon atmosphere, followed by the addition of a mixture of DI water and nitric acid (HNO 3 ) in air (molar ratio of components HfCl 4 :EtOH:HNO 3 : H 2 O=1:410:5:5).…”