Scaling of equivalent oxide thickness of atomic layer deposited HfO2 film using RuO2 electrodes suppressing the dielectric dead-layer effect

Abstract

The influences of RuO2 metal gate on the dielectric performance of high-k HfO2 film on Si substrate were examined. The equivalent oxide thickness (EOT) of HfO2 film can be scaled down by similar to 0.5 nm in the EOT range from 0.8 to 2.5 nm compared with the standard Pt gate case. This was attributed to the suppression of the dielectric dead-layer effect at the HfO2/RuO2 interface due to the possible ionic polarization of RuO2 within the screening length of the electrode. The estimated work function of RuO2 on HfO2 is similar to 5.0 eV suggesting the appropriateness of RuO2 for p-transistor. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4764541]