Mechanism of improved channel carrier mobility for stacked Y2O3∕HfO2 gate dielectric

Stacked Y2O3∕HfO2 gate dielectric, compared to HfO2, shows significantly enhanced electron channel mobility at different temperatures. This mobility improvement can be attributed to reduced remote phonon scattering, which is associated with the smaller ionic polarization of Y2O3, and the suppressed Coulomb scattering due to less electron trapping in the bulk of high-κ layer and reduced metal impurities in the substrate.