Abstract
The electrical characteristics of metal–oxide–semiconductor (MOS) device with Sc gate on atomic-layer-deposited (ALD) HfO2 were evaluated, for the first time. The equivalent oxide thickness (EOT) was reduced after post-metallization annealing even at 200°C. The reduction of EOT may be attributed to the diffusion of oxygen from the interfacial layer between HfO2 and Si substrate to the Sc gate. In case of optimum annealing condition, Sc gate can reduce EOT without degradation of leakage current and interfacial quality. The estimated effective work function of Sc was ∼3.8 eV and Sc might be a candidate for the gate electrode of n-type MOS devices.