PHYSICAL ORIGINS OF MOBILITY REDUCTION IN HIGH-K GATE TRANSISTORS

摘要

We review the current status of our understanding the mechanisms for the mobility reduction in Metal-Insulator-Semiconductor Field-Effect-Transistors with high permittivity (high-K) gate dielectrics. The various scattering sources have been identified as being responsible for the mobility reduction including fixed charges, infrfacial dipoles, remote-phonons, remote-surface roughness, phase separation, and crystallization. All these scattering sources are located away from the channel, and therefore, the scattering is called as the remote scattering. We developed a comprehensive mobility model that includes most of these scatterings, based on the quantum mechanical linear response theory. We discuss the impacts of each scattering source on the mobility, and the possible solution to improve it by optimizing the process conditions.