Atomic model for Negative Capacitance FET

G. Liang
National Unoversity of Singapore,



In this talk, a full atomic model was developed and constructed based on real space atomic Poisson solver, full complex bandstructure, and Gibbs free energy of the total atomic system. Gibbs free energy of the whole atomic system was employed to determine the stable operation region in P-E path of ferroelectric MOSFETs with different FE materials and gate structures. The performance of NC-FETs based on real-space analysis was investigated in depth for different device structures using full atomic model. We found that dΨS/dVG ratio becomes worse with increased channel length which cannot be observed by capacitance model. This causes the tradeoff between the low tunneling current and large dΨS/dVG ratio, which makes it difficult to improve SS by increasing gate length. In addition, NC-FETs with and without floating metal between FE and SiO2 layers were investigated in atomic level for different channel lengths for the first time. The metal has stronger influence in the electric characteristics of NC-FETs with longer channel.