Analytic model for the electrical properties of negative capacitance metal-ferroelectric insulator silicon (MFIS) capacitor

Ferroelectric negative capacitance

“…The specific application or device also needs to be considered, because it determines the environment of the ferroelectric and its response. FETs are currently the most interesting and beststudied case, and the impact of various design variables (size, shape, response and conductivity of the different components) on the volt age amplification effect is being intensively investigated, including by dynamic simulation studies 20,51,71,93,94,[108][109][110][111][112][113][114][115][116][117][118] . Applying NC effects in transistors is challenging owing to the presence of free carriers in the channel, which is in contact with the source and drain, complicating the realization of chargecontrol conditions as well as the stabilization of the NC state.…”

Analytical model for the effects of the variation of ferrolectric material parameters on the minimum subthreshold swing in negative capacitance capacitor

“…Because our study examines the properties of a ferroelectric layer, we are not going to examine the electrical characteristics of the NC-FET and will instead limit our study to the capacitor only. The subthreshold swing (SS) of a MOSFET device is defined as the change in gate voltage (V GS ) required to change the drain current (I D ) by one order of magnitude [9] . For the negative capacitance MOS capacitor equivalent shown in Fig.…”

“…The total charge Q is the same as the total charge in the channel, which is calculated using the depletion width approximation and has already explained in Ref. [10]. The potential balance in the equivalent capacitor network results in applied gate voltage V GS as the sum of the voltage drop across the ferroelectric capacitor (V FE ) and the internal node voltage V GMOS is giv-en as…”

“…Mathematically, the condition for being in subthreshold is given by (where is the surface potential, is the built-in potential on p-substrate, N A is the substrate doping and n i is the intrinsic carrier concentration), throughout the NC-regime. For uniform substrate doping and the partially depleted case, is related to the depletion charge Q by [9]…”