Field-effect transistors based on two-dimensional materials could potentially be used in very large-scale integration (VLSI) technology. But whether they can be used at the front end of line or at the back end of line through monolithic or heterogeneous integration remains to be seen. In order to achieve this, multiple challenges must be overcome including reducing contact resistance, developing stable and controllable doping schemes, advancing mobility engineering, and improving high-k dielectric integration. The large-area growth of uniform 2D layers is also required to ensure low defect density, low device-to-device variation, and clean interfaces. Here we review the development of 2D field-effect transistors for use in future VLSI technologies. We consider the key performance indicators for aggressively scaled 2D transistors and discuss how these should be extracted and reported.We also highlight potential applications of 2D transistors in conventional micro/nanoelectronics, neuromorphic computing, advanced sensing, data storage, and future interconnect technologies.

The tunnel field-effect transistor (TFET) is considered a future transistor option due to its steep-slope prospects and the resulting advantages in operating at low supply voltage (V DD ). In this paper, using atomistic quantum models that are in agreement with experimental TFET devices, we are reviewing TFETs prospects at L G = 13 nm node together with the main challenges and benefits of its implementation. Significant power savings at iso-performance to CMOS are shown for GaSb/InAs TFET, but only for performance targets which use lower than conventional V DD . Also, P-TFET current-drive is between 1× to 0.5× of N-TFET, depending on choice of I OFF and V DD . There are many challenges to realizing TFETs in products, such as the requirement of high quality III-V materials and oxides with very thin body dimensions, and the TFET's layout density and reliability issues due to its source/drain asymmetry. Yet, extremely parallelizable products, such as graphics cores, show the prospect of longer battery life at a cost of some chip area.INDEX TERMS Tunnel field-effect transistor (TFET), steep-slope.

Direct bandgap transition engineering using stress, alloying, and quantum confinement is proposed to achieve high performing complementary n and p tunneling field effect transistors (TFETs) based on group IV materials. The critical tensile stress for this transition decreases in Ge1−xSnx for Sn content 0≤x≤0.068, calculated with the Nonlocal Empirical Pseudopotential method. Direct sub eV bandgap leads to high ON current in both n and p Ge and Ge1−xSnx TFETs, simulated using the sp3d5s*-SO model. Ge and Ge1−xSnx show an advantage over III-V p TFETs achieving steep subthreshold operation, which is limited in III-V devices by their low density of electron states.

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Transient negative differential capacitance (NC), the dynamic reversal of transient capacitance in an electrical circuit is of highly technological and scientific interest since it probes the foundation of ferroelectricity. In this letter, we study a resistor-ferroelectric capacitor (R-FeC) network through a series of coupled equations based on Kirchhoffs law, Electrostatics, and Landau theory. We show that transient NC in a R-FeC circuit originates from the mismatch between rate of free charge change on the metal plate and that of bound charge change in a ferroelectric (FE) capacitor during polarization switching. This transient charge dynamic mismatch is driven by the negative curvature of the FE free energy landscape. It is also analytically shown that a free energy profile with the negative curvature is the only physical system that can describe transient NC during the two-state switching in a FE capacitor. Furthermore, this transient charge dynamic mismatch is justified by the dependence of external resistance and intrinsic FE viscosity coefficient. The depolarization effect on FE capacitors also shows the importance of negative curvature to transient NC. The relation between transient NC and negative curvature provides a direct insight into the free energy landscape during the FE switching.