Performance Improvement of sol-gel prepared cerium oxide as gate oxide on Si MOS with various volumes of the chelating agent

Abstract

In this study, a cerium oxide (CeO2) thin film on Metal-Oxide-Semiconductor (MOS) structure was prepared by sol-gel method. Cerium nitrate (Ce(NO3)3·6H2O) powder and isopropanol solution was used as the coating solution and various chelating agent (glacial acetic acid) volumes of 0, 2, 3, 4, and 5 ml were mixed in hit to prepare CeO2 films, and annealed with oxygen for 1 hour. The electrical characteristics were measured to examine the film qualities, including oxide capacitance (Cox), leakage current density, k value, equivalent oxide thickness (EOT), effective oxide charge density (QEFF), and interface density (Dit). The corresponding values are 79.1 pF, 6.4×10^-4 A/cm² at +5V, 24, 30.9 nm, 2.03×10¹¹ cm^-2, and 1.93 × 10¹¹ cm^-2eV^-1, respectively. Based on these data, it can be considered that CeO2 thin films by sol-gel method on Si exhibit a good quality and can be used as an advanced gate oxide on MOS structure in the near future.