查看文章

We report a proof-of-concept demonstration of negative capacitance effect in a nanoscale ferroelectric-dielectric heterostructure. In a bilayer of ferroelectric Pb (Zr 0.2 Ti 0.8) O 3 and dielectric SrTiO 3, the composite capacitance was observed to be larger than the constituent SrTiO 3 capacitance, indicating an effective negative capacitance of the constituent Pb (Zr 0.2 Ti 0.8) O 3 layer. Temperature is shown to be an effective tuning parameter for the ferroelectric negative capacitance and the degree of capacitance enhancement in the heterostructure. Landau’s mean field theory based calculations show qualitative agreement with observed effects. This work underpins the possibility that by replacing gate oxides by ferroelectrics in nanoscale transistors, the sub threshold slope can be lowered below the classical limit (60 mV/decade).