Experimental Details of a Steep-Slope Ferroelectric InGaAs Tunnel-FET With High-Quality PZT and Modeling Insights in the Transient Polarization

Abstract

The steep-slope ferroelectric tunnel-FET (SS-FeTFET), consisting of an InGaAs TFET with sub-60 mV/dec subthreshold swing (SS) at room temperature and an externally connected high-quality single-crystalline PZT capacitor, displays improved SS compared to the standalone TFET. In our manuscript, we describe the measurement procedure and measurement results of this SS-FeTFET in great detail. To quantitatively extract the ferroelectric polarization during voltage sweeps, device simulations of the TFET are combined with the SS-FeTFET measurement results. Finally, qualitative insight in some pecularities of the experimental observations are given, like the apparent coercive voltage which is larger in the SS-FeTFET than in the standalone ferroelectric, the shape of the polarization during voltage sweeps and the small polarization hysteresis loop at voltages close to the apparent coercive voltage.

Stepwise internal potential jumps caused by multiple-domain polarization flips in metal/ferroelectric/metal/paraelectric/metal stack

“…The requirement for this condition is the same as that for stabilizing NC effect originally proposed. This is also partly consistent with a recent report in which nearly single domain PZT film together with strict capacitance matching was employed and a nearly hysteresis-free steep SS was demonstrated 23,24 . In the case of FE layer containing multiple domains, the hysteresis-free V int gain is difficult to achieve perfectly.…”

“…Several models of quasi-static NC associated with domain wall motion in a multiple-domain system have been also proposed [9][10][11][12][13] . Meanwhile, steep SS values have been demonstrated by incorporating FE/PE gate stacks into FETs with various FE materials [14][15][16] , various channel materials 15,[17][18][19] and various FET structures 14,[20][21][22][23][24] .…”

Ultralow Subthreshold Swing of a MOSFET Caused by Ferroelectric Polarization Reversal of Hf0.5Zr0.5O2 Thin Films

“…Large V int jumps can be seen during the forward and reverse V G sweeps. The large jumps can make the differential relationship d V int /d V G ≫ 1 (see Section 4 in the Supporting Information), typically called the internal potential gain, − resulting in the ultralow SS. The V FE (calculated by subtracting measured V int from V G ) as a function of V G is shown in Figure b.…”

Assessment of the Biosensing Capabilities of SiGe Heterojunction Negative Capacitance-Vertical Tunnel Field-Effect Transistor

“… T normalW normalK normalB ( E ) ≈ exp ( − 4 λ · 2 m * · E normalg 3 / 2 3 q · false| e false| h false( δ ϕ + E g false) ) · I normalo normaln where, effective mass ( m *), energy band gap ( E g ), and tunneling height ( h ) are symbols for the corresponding quantities. Charge diffusion from the source to channel makes it difficult to establish abrupt junctions in TFETs, which results in random dopant fluctuations and lower device performance. − These are just a few of the challenges that TFET encounters. Additionally, the low ON current ( I ON ) and enhanced ambipolarity of TFETs reduce their sensitivity and limit their usage in real-time applications. − Numerous VTFET configurations incorporate dual sources to address ambipolarity issues, thereby reducing leakage current and enhancing device performance. , Little progress has been achieved in developing complex TFET device topologies using current CMOS manufacturing techniques, despite attempts to boost the TFET sensitivity by structural alterations.…”