Growth and Film Properties of Plasma-Enhanced and Thermal Atomic-Layer-Deposited Magnesium Oxide Films Using Bis(ethylcyclopentadienyl)Magnesium Precursor

Abstract

As the device scaling of dynamic random access memory continues, the demand for the development of new dielectric film with high permittivity and low leakage current that may replace the currently used ZrO2/Al2O3-based dielectric film has increased drastically. In this aspect, MgO thin film has been spotlighted due to its high band gap (7-8 eV) and moderate dielectric constant (9-10).In this study, we investigated the growth behavior and film properties of the MgO ALD film using Mg(EtCp)2 precursor and the different reactants of H2O and O2 plasma. MgO thin films were deposited at the temperature range of 200-400°C, and the self-limited surface reaction was observed to secure optimal growth conditions. Glancing angle X-ray diffraction and X-ray photoelectron spectroscopy were used to examine crystalline structure and chemical properties, respectively. To evaluate the electrical characteristics of the MgO films, the Pt/MgO/TiN capacitor was fabricated with different MgO thicknesses at various deposition temperatures. The electrical characteristics such as dielectric constant and leakage current density of the MgO film were examined depending on the reactants, and the leakage current conduction mechanism of the MgO thin films was elucidated. Figure 1