High-K Gate Dielectrics Treated with in Situ Atomic Layer Bombardment

Because the dielectric constant (K), the leakage current density (J(g)), and the interfacial state density (D-it) 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 J(g) by similar to 3 orders of magnitude, together with an similar to 11% increase of K value and a decrease of D-it, of high-K gate dielectrics. The suppressed J(g) 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 D-it. 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.