>>>paper identification number<<< 1 Abstract —This paper reports for the first time an intricate analysis of gate length dependence of the transient negative capacitance induced pruning of the short-channel effects in hafnium zirconium oxide based ferroelectric fin-FET devices. We have fabricated devices with 10nm thick hafnium zirconium oxide based ferroelectric Fin-FETs with fin width of 20nm and 25nm. The gate lengths are varied as 50nm, 70nm, 80nm and 150nm and transient negative capacitance induced alleviation of short channel effect in terms of subthreshold slope improvement have been analyzed and modelled. Further study has been conducted by simulating double gate ferroelectric FinFETs with channel lengths ranging from 25nm to 100nm using TCAD. The results show that ferroelectricity significantly reduces subthreshold swing and the impact is found to be significantly feistier in short channel devices than long channel ones, which demonstrates the tremendous advantage of using ferroelectric gate stack for scaled MOSFETs. Further a compact analytical formulation is developed to quantify sub-threshold swing improvement for short channel devices. Index Terms — analytical model, DIBL, ferroelectric, FinFET, negative capacitance, short channel effect, subthreshold swing. I. INTRODUCTION HE recent progress in the research of CMOS-compatible ferroelectric hafnium zirconium oxide(HZO) has paved the way for implementation of next generation ferroelectric memory[1,2] along with this, the advent of the research in the field of differential negative capacitance(NC) in HZO can also assist in subjugating the “Boltzmann Tyranny” for advanced logic devices[3]. Amidst a numerous research on the impact of negative capacitance and the reliability issues associated with them [4-8], the topic of negative capacitance has been a matter of dissension amongst the scientific community. The origin of additional steepness beyond 60mV/dec in ferroelectric traditional field effect transistors has been described by divergent physical phenomena by different groups. The origin was first ascribed to the quasi-static negative capacitance (QS- NC) concept, which used single-domain landau formalism for ferroelectric switching to predict the plausible existence of negative capacitance in ferroelectric FET [9-18]. This work was jointly supported by the Ministry of Science and Technology (Taiwan) grant MOST-108-2634-F-006-08 and is part of research work by MOST’s AI Biomedical Research Center. Sourav De, Bo-Han Qiu , Jhang-Yan Ciou, Chi-Jen Lin, Wei-Chih Tseng Chien-Wei-Wang, Md. Aftab Baig, and Darsen Lu are associated with the Department of Electrical Engineering and the Institute of Microelectronics of National Cheng Kung University (NCKU), Tainan, Taiwan R.O.C. (e-mail: darsenlu@mail.ncku.edu.tw) Yao-Jen Lee is associated with Taiwan Semiconductor Research Institute, Hsinchu, Taiwan. The red curve in Fig.1(a). depicts the switching path required for attaining the QS-NC region, where presence of more than one domain is interdicted. Apart from this, the interfacial dielectric layer also plays a pivotal role to impel the ferroelectric layer into the QS-NC state [9]. As, it is evident from the Fig.1(b). that QS-NC region lies within a thermodynamically unstable region in Gibbs’ free energy curve for ferroelectric. Therefore, an additional matching interfacial dielectric layer is required to artificially steer the single-domain ferroelectric layer in the negative capacitance region. Apart from this, the random distribution of phase and trapping-detrapping phenomena in HZO infuses additional obscurity along with requisite of fabricating devices with a single-domain to attain QS-NC state. Therefore, obtaining QS-NC hysteresis free MOSFET is pretty abstruse in real scenario. (a) (b) Fig. 1. (a). The polarization vs electric field curve shows the possible polarization switching paths for ferroelectric capacitors. (b) The Gibbs’ free energy for ferroelectric switching shows the quasi-static negative capacitance region, which is thermodynamically unstable in general. Although, some recent developments on the direct observation of the negative capacitance in some literatures have also reinforced the existence of “S” along with plausible “modus operandi” to drive the ferroelectric thin film into QS-NC state [19,20]. However, some explanations regarding single domain “S” curve extraction remains iffy. Therefore, some recent researches enunciate their dubious notion towards experimental procedures of these researches and the existence of QS-NC, providing us with some alternative explanations of non- linearity incited dynamic snap-back effect, about the origin of Characterization and Modelling of Gate Length Impact on the Transient Negative Capacitance Induced Control of Short Channel Effect in Ferroelectric Fin-FETS Sourav De, IEEE Student Member, Bo-Han Qiu, Jhang-Yan Ciou, Chi-Jen Lin, Wei-Chih Tseng Chien-Wei-Wang, Md. Aftab Baig, Yao-Jen Lee and Darsen Lu*, Senior Member, IEEE, and Darsen Lu, Member, IEEE T                           