High-<i>K</i> Gate Dielectrics Treated with <i>in Situ</i> Atomic Layer Bombardment

Abstract

Because the dielectric constant (K), the leakage current density (Jg), and the interfacial state density (Dit) are critical to high-K gate dielectrics, the layer-by-layer, in situ atomic layer bombardment (ALB) is proposed and explored to enhance these electrical properties in this study. The in situ helium/argon plasma bombardment was performed layer-by-layer in each cycle of atomic layer deposition (ALD) for preparing high-K gate dielectrics. As compared with the untreated high-K layer, the ALB treatment contributes to a significant reduction in Jg by ∼3 orders of magnitude, together with an ∼11% increase of K value and a decrease of Dit, of high-K gate dielectrics. The suppressed Jg and the enhanced K value are ascribed to an increase of film density and a decrease of oxygen vacancies in the ZrO2 layer by the ALB treatment. The atomic annealing effect due to the ALB technique contributes to the decrease of Dit. The result demonstrates that the ALD together with the ALB technique is highly effective to further enhance the dielectric properties of nanoscale thin films, which is important and applicable in a variety of fields including nanoelectronic, energy-saving, and biomedical devices.