Physical Mechanisms of Reverse DIBL and NDR in FeFETs with Steep Subthreshold Swing

Abstract

We have investigated transient {I} _{\mathrm{ d}}\,\,-\,\,{V} _{\mathrm{ g}} and {I} _{\mathrm{ d}}\,\,-\,\,{V} _{\mathrm{ d}} characteristics of ferroelectric field-effect transistor (FeFET) by simulation with ferroelectric model considering polarization switching dynamics. We show transient negative capacitance (TNC) with polarization reversal and depolarization effect can result in sub-60mV/dec subthreshold swing (SS), reverse drain-induced barrier lowering (R-DIBL), and negative differential resistance (NDR) without traversing the quasi-static negative capacitance (QSNC) region of the S-shaped polarization-voltage ( {P}-{V} ) predicted by single-domain Landau theory. Moreover, the mechanisms of R-DIBL and NDR based on the TNC theory are discussed in detail. The results demonstrated in this work can be a possible explanation for the mechanism of previously reported negative capacitance field-effect transistor (NCFET) with sub-60mV/dec SS, R-DIBL, and NDR.