Resonant tunneling in stacked dielectrics: a novel approach for obtaining the electron tunneling mass-conduction band offset energy products for advanced gate dielectrics

摘要

There has been a search for alternative dielectrics with significantly increased dielectric constants, k, which increases in physical thickness proportional to k, and therefore would significantly reduce direct tunneling. However, increases in k to values of 15 to 25 in transition metal and rare earth oxides are generally accompanied by decreases in the conduction band offset energy, E{sub}B, with respect to Si, and in the effective electron tunneling mass, m{sub}(eff), which mitigate gains from increased thickness. A novel technique, based on stacked dielectrics, is used to obtain the tunneling mass-conduction band offset energy product. When combined with spectroscopic estimates of tunneling barriers, this yields values for the tunneling mass.