Design and Implementation of Ternary Logic Integrated Circuits by Using Novel Two-Dimensional Materials

A Ternary Inverter Based on Hybrid Conduction Mechanism of Band-to-Band Tunneling and Drift-Diffusion Process

In this paper, a novel transistor based on a hybrid conduction mechanism of band-to-band tunneling and drift-diffusion is proposed and investigated with the aid of TCAD tools. Besides the on and off states, the proposed device presents an additional intermediate state between the on and off states. Based on the tri-state behavior of the proposed TDFET (tunneling and drift-diffusion field-effect transistor), a ternary inverter is designed and its operation principle is studied in detail. It was found that this device achieves ternary logic with only two components, and its structure is simple. In addition, the influence of the supply voltage and the key device parameters are also investigated.

Anti-Ambipolar Heterojunctions: Materials, Devices, and Circuits

Anti-ambipolar heterojunctions are vital in constructing high-frequency oscillators, fast switches, and multivalued logic (MVL) devices, which hold promising potential for next-generation integrated circuit chips and telecommunication technologies. Thanks to the strategic material design and device integration, anti-ambipolar heterojunctions have demonstrated unparalleled device and circuit performance that surpasses other semiconducting material systems. This review aims to provide a comprehensive summary of the achievements in the field of anti-ambipolar heterojunctions. First, the fundamental operating mechanisms of anti-ambipolar devices are discussed. After that, potential materials used in anti-ambipolar devices are discussed with particular attention to 2D-based, 1D-based, and organic-based heterojunctions. Next, the primary device applications employing anti-ambipolar heterojunctions, including anti-ambipolar transistors (AATs), photodetectors, frequency doublers, and synaptic devices, are summarized. Furthermore, alongside the advancements in individual devices, the practical integration of these devices at the circuit level, including topics such as MVL circuits, complex logic gates, and spiking neuron circuits, is also discussed. Lastly, the present key challenges and future research directions concerning anti-ambipolar heterojunctions and their applications are also emphasized.

New ternary inverter with memory function using silicon feedback field-effect transistors

In this study, we present a fully complementary metal-oxide-semiconductor-compatible ternary inverter with a memory function using silicon feedback field-effect transistors (FBFETs). FBFETs operate with a positive feedback loop by carrier accumulation in their channels, which allows to achieve excellent memory characteristics with extremely low subthreshold swings. This hybrid operation of the switching and memory functions enables FBFETs to implement memory operation in a conventional CMOS logic scheme. The inverter comprising p- and n-channel FBFETs in series can be in ternary logic states and retain these states during the hold operation owing to the switching and memory functions of FBFETs. It exhibits a high voltage gain of approximately 73 V/V, logic holding time of 150 s, and reliable endurance of approximately 10⁵. This ternary inverter with memory function demonstrates possibilities for a new computing paradigm in multivalued logic applications.

Molecular Engineering of Printed Semiconducting Blends to Develop Organic Integrated Circuits: Crystallization, Charge Transport, and Device Application Analyses

Solution-based printing has contributed to the facile deposition of various types of materials, including the building blocks of printed electronics. In particular, solution-processable organic semiconductors (OSCs) are regarded as one of the most fascinating candidates for the fabrication of printed electronics. Herein, we report electrohydrodynamic (EHD) jet-printed p- and n-type OSCs, namely 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-PEN) and 6,13-bis((triisopropylsilyl)ethynyl)-5,7,12,14-tetraazapentacene (TIPS-TAP), and their use as single-OSC layers and as OSC mixed p-n layers to fabricate solution-processed p-, n-, and ambipolar-type organic field-effect transistors (OFETs). Use of the dragging mode of EHD jet printing, a process driven under a low electrostatic field with a short nozzle-to-substrate distance, was found to provide favorable conditions for growth of TIPS-PEN and TIPS-TAP crystals. In this way, the similar molecular structures of TIPS-PEN and TIPS-TAP yielded a homogeneous solid solution and showed ambipolar transport properties in OFETs. Therefore, the combination of single- and mixed-OSC layers enabled the preparation of various charge-transported devices from unit to integrated devices (NOT, NAND, NOR, and multivalued logic). Therefore, this fabrication technology can be useful for assisting in the production of OSC layers for practical applications in the near future.

Modeling of molecular ternary logic gates and circuits based on diode structures

Modeling in molecular electronics is of great importance, and the use of semiconductor components for this type of modeling accelerates the development process in this field. In this work, a typical circuit model is proposed for modeling molecular components. Accordingly, an asymmetric oligo-phenylene vinylene (OPV) molecular diode and a bipyridine-biborinine molecular diode are modeled. A good agreement is observed between the current curves from the proposed circuit models and the atomic simulations of the molecules. Additionally, the electron density, the distribution of molecular orbitals, and the potential drop profile at + 1 and - 1 V are obtained and analyzed for the bipyridine-biborinine molecular diode using the density functional theory (DFT) in combination with the non-equilibrium Green's function (NEGF). Using different molecular gates and circuits based on the molecular devices, we have modeled the ternary NOT logic gate, ternary NOR logic gate, ternary NAND logic gate, negative ternary inverter (NTI) logic gate, positive ternary inverter (PTI) logic gate, ternary buffer, ternary decoder, and ternary half adder.

Reconfigurable Multivalue Logic Functions of a Silicon Ellipsoidal Quantum-Dot Transistor Operating at Room Temperature

Reconfigurable multivalue logic functions, which can perform the versatile arithmetic computation of weighted electronic data information, are demonstrated at room temperature on an all-around-gate silicon ellipsoidal quantum-dot transistor. The large single-hole transport energy of the silicon quantum ellipsoid allows the stable M-shaped Coulomb blockade oscillation characteristics at room temperature, and the all-around-gate structure of the fabricated transistor enables us to perform the precise self-control of the energetic Coulomb blockade conditions by changing the applied bias voltage. Such a self-controllability of the M-shaped Coulomb blockade oscillation characteristics provides a great advantage to choose multiple operation points for the reconfigurable multivalue logic functions. Consequently, the weighted data states (e.g., tri-value and quattro-value) are effectively demonstrated by utilizing only the device physics in the all-around-gate silicon ellipsoidal quantum-dot transistor. These findings are of great benefit for the practical application of the silicon quantum device at an elevated temperature for future nanoelectronic information technology.

Negative differential transconductance device with a stepped gate dielectric for multi-valued logic circuits

Multi-valued logic (MVL) technology is a promising approach for improving the data-handling capabilities and decreasing the power consumption of integrated circuits. This is especially attractive as conventional complementary metal-oxide-semiconductor technology is approaching its scaling and power density limits. Here, an ambipolar WSe₂ field-effect transistor with two or more negative-differential-transconductance (NDT) regions in its transfer characteristic (NDTFET) is proposed for MVL applications of various radices. The operation and charge carrier transport mechanism of the NDTFET are studied first by Kelvin probe force microscopy, electrical, and capacitance-voltage measurements. Next, strategies for increasing the number of NDT regions and engineering the NDTFET transfer characteristic are discussed. Finally, the extensibility and tunability of our concept are demonstrated by adapting NDTFETs as core devices for ternary, quaternary, and quinary MVL inverters through simulations, where only WSe₂ is employed as a channel material for all devices comprising the inverters. The MVL inverter operation principle and the mechanism of the multiple logic state formation are analyzed in detail. The proposed concept is practically verified by the fabrication of a ternary inverter.