Preparation and characterization of Gd2O3-doped HfO2 high-k gate dielectric thin films by RF sputtering

Abstract

Research was carried out on the growth and characterization of Gd2O3-doped HfO2 thin films as gate dielectrics for Si CMOS technology prepared by RF magnetron co-sputtering. The crystal morphology, composition and electrical properties of both Gd2O3-doped and as grown HfO2 gate dielectrics have been comparatively investigated. Cross-section high-resolution transmission electron microscopy (HRTEM) reveals that all the deposited high-k gate dielectrics display amorphous structures with a thickness of ∼10nm. C-V and I-V measurements indicate the pronounced reductions of dielectric loss, equivalent oxide thickness (EOT), as well as the leakage current for Gd2O3-doped HfO2 thin films. Moreover, the calculated dielectric constants significantly increase from 20.2 to 31.6 and less hysteresis in the reverse sweeping could also be observed as the doping content of Gd2O3 increases.