Search

Abstract: Chemically conformal deposition of SrTiO3 (STO) thin films was successfully achieved by ALD using conventional metal organic precursors and remote-plasma activated H2O. It was found that the ALD behavior of the STO film was critically dependent on the Sr(thd)2 source bubbling temperature. When the Sr-source bubbling temperature was <∼200 °C (Sr(thd)2 melting temperature), the deposition proceeded in a genuine ALD mode and stoichiometric STO films were deposited with a good process reliability. Relatively good electrical properties were obtained from a planar capacitor structure with Pt top and Ru bottom electrodes. A 19.5-nm-thick STO film showed an equivalent oxide thickness (EOT) of 0.8 nm and a leakage current density of 1.98×10−6 A/cm2 at 1V after post-annealing. [Copyright &y& Elsevier]

Abstract: A thin (∼ 0.5 nm) layer of Hf metal was deposited on an atomic layer deposited (ALD) HfO2 film by the DC sputtering method. X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy analyses showed that the Hf metal layer transformed into HfO2 during the post-deposition annealing process. It appears that the HfO2 layer formed by the oxidation of Hf metal provided the underlying ALD HfO2 layer with the nucleation sites necessary to decrease the grain-boundary density of the crystallized HfO2 film. The decrease in the grain-boundary density resulted in a reduction in the Hf-silicate formation and interfacial layer growth during post deposition annealing. This eventually resulted in a smaller increase in the capacitance equivalent thickness (CET) and high-k characteristics in the CET vs. leakage current density curve even after post deposition annealing at 1000 °C. [Copyright &y& Elsevier]

Abstract: In this work, we have prepared metal–insulator–metal capacitors for dynamic random access memory capacitor application using atomic layer deposition of TiO2 high-κ dielectric and RuO2 bottom electrode. We compare TiO2 layers grown using TiCl4 precursor or Ti-tetra-isopropoxide precursor, and Al-doped TiO2 layers grown using Ti-tetra-isopropoxide precursor. The capacitors were analyzed in the terms of capacitance – voltage and current – voltage measurements and transmission electron microscopy imaging. [Copyright &y& Elsevier]