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This paper is dedicated to a review of the international effort to map the future of nanoelectronics from materials to systems for the new electronics industry. The following sections are highlighted: the Roadmap structure with the international teams, the methodology and historical evolution, the various eras of scaling, the new ecosystems and computer industry, the evolving supply chain, the development of SoC and SiP, the advent of the Internet of Everything and the 5G communications, the dramatic increase of data centers, the power challenge, the technology fusion, heterogeneous and system integration, the emerging technologies, devices and computing architectures, and the main challenges for future applications. [ABSTRACT FROM AUTHOR]

Joule's law opens a straightforward way to explore the operating mechanism of organic field-effect transistors, from the angle of inner transported heating. The microscopic dissipated power is calculated from the local conductivity and electric field, which solves the widespread difficulties in building a macroscopic model to determine the contact resistance. The result quantitatively discloses the correlation between the contact resistance and the charge transport properties covering energetic disorder, band-like and hopping transport as well as carrier mobility anisotropy. It turns out that in a staggered configuration with ideal Ohmic contact, the contact resistance is highly affected by the charge transport. [ABSTRACT FROM AUTHOR]

Unreliable mobility values, and particularly greatly overestimated values and severely distorted temperature dependences, have recently hampered the development of the organic transistor field. Given that organic field‐effect transistors (OFETs) have been routinely used to evaluate mobility, precise parameter extraction using the electrical properties of OFETs is thus of primary importance. This review examines the origins of the various mobilities that must be determined for OFET applications, the relevant extraction methods, and the data selection limitations, which help in avoiding conceptual errors during mobility extraction. For increased precision, the review also discusses device fabrication considerations, calibration of both the specific gate‐dielectric capacitance and the threshold voltage, the contact effects, and the bias and temperature dependences, which must actually be handled with great care but have mostly been overlooked to date. This review serves as a systematic overview of the OFET mobility extraction process to ensure high precision and will also aid in improving future research. [ABSTRACT FROM AUTHOR]

A study of carrier transport in top-gate and bottom-contact TIPS-pentacene organic field-effect transistors (OFETs) based on mobility is presented. Among three mobilities extracted by different methods, the low-field mobility obtained by the Y function exhibits the best reliability and ease for use, whereas the widely applied field-effect mobility is not reliable, particularly in short-channel transistors and at low temperatures. A detailed study of contact transport reveals its strong impact on short-channel transistors, suggesting that a more intrinsic transport analysis is better implemented in relatively longer-channel devices. The observed temperature dependences of mobility are well explained by a transport model with Gaussian-like diffusivity band tails, different from diffusion in localized states band tails. This model explicitly interprets the non-zero constant mobility at low temperatures and clearly demonstrates the effects of disorder and hopping transport on temperature and carrier density dependences of mobility in organic transistors. [ABSTRACT FROM AUTHOR]

A modeling of organic field-effect transistors' (OFETs') electrical characteristics is presented. This model is based on a one-dimensional (1-D) Poisson's equation solution that solves the potential profile in the organic semiconducting film. Most importantly, it demonstrates that, due to the common open-surface configuration used in organic transistors, the conduction occurs in the film volume below threshold. This is because the potential at the free surface is not fixed to zero but rather rises also with the gate bias. The tail of carrier concentration at the free surface is therefore significantly modulated by the gate bias, which partially explains the gate-voltage dependent contact resistance. At the same time in the so-called subthreshold region, we observe a clear charge trapping from the difference between C-V and I-V measurements; hence a traps study by numerical simulation is also performed. By combining the analytical modeling and the traps analysis, the questions on the C-V and I-V characteristics are answered. Finally, the combined results obtained with traps fit well the experimental data in both pentacene and bis(triisopropylsilylethynyl)-pentacene OFETs. [ABSTRACT FROM AUTHOR]

The reliability of mobility evaluation of organic field-effect transistors (OFETs) is a serious issue because numerous overestimated and underestimated mobilities have been reported recently. A reliable approach to accurately evaluate the OFET mobility is therefore highly desirable. Here, in this letter, two commonly employed methods and the Y function method (YFM) were used to extract the mobilities of indacenodithiophene-co-benzothiadiazole (IDT-BT) OFETs with four different contact metals. The mobilities extracted by the commonly used methods varied greatly with the contact metal and channel length, whereas those extracted by the YFM were very stable and approached the intrinsic mobility of IDT-BT. Our results show that YFM is a precise approach that can be widely used to evaluate the OFET mobility. [ABSTRACT FROM AUTHOR]

Low-frequency noise (LFN) in double-gate (DG) In–Ga–Zn–O (IGZO) thin-film transistors (TFTs) is studied to investigate the origin of performance improvement. We found that thinning down the IGZO film enhances such improvements. With 7-nm IGZO, the mobility is raised by a factor of 3.77, and the subthreshold slope is reduced to 0.17 V/decade from single-gate to DG mode. Device simulations show that bulk transport inside IGZO film emerges as the two gates field effects get coupled. The LFN results reveal a transport transition from surface to bulk and disclose the superior bulk transport that experiences slight phonon scattering with a small Hooge parameter \alpha H = 4.44 \times 10^{\mathrm {-3}} , whereas the surface transport undergoes serious charge trapping with surface trap densities about 2 \times 10^11 eV ^-1 cm ^-2 . [ABSTRACT FROM PUBLISHER]

Inspired by the silicide technology in manufacturing silicon devices and the ongoing lack of knowledge on post-metallization annealing in realizing oxide devices, we investigated post-contact annealing for solution-processed InGaZnO transistors. Low-temperature annealing in air is found to significantly improve device uniformity, reproducibility, and subthreshold charge transport. However, this method is highly dependent on the employed contact metal. Detailed examination of devices using Al, Au, and Cu reveals that the physics of a metal/semiconductor interface is vital to its post-anneal response, which results in distinct device characteristics. Our results provide clues to better understand oxide transistors and to optimize their performance. [ABSTRACT FROM AUTHOR]

Investigates hot-carrier effects (HCE) induced by the parasitic bipolar transistor (PBT) action in deep submicron N-channel silicon-on-insulator (SOI) metal oxide semiconductor field-effect transistors (MOSFET). Experimental details; Experimental results and numerical simulations; Conclusion.

Close correlation between low-frequency noise and charge transport in pentacene transistors is observed. The trap density evolving with pentacene deposition reveals transformation of growth phase and different transport mechanisms. It explains the greatly altered mobility and contact resistance in which the upper surface's trapping plays an important role. Inspecting contact noise shows high density of traps at contacts that result possibly from pyramid like growth of pentacene or contact damage or both. [ABSTRACT FROM AUTHOR]

Influences of contact thickness on bottom-contact and bottom-gate coplanar organic transistors are studied. In transistors with poor-quality pentacene films, thick contacts improve mobility and lower contact resistance. However, in transistors with high-quality pentacene films, thick contacts significantly degrade performance by disrupting molecular self-organization at the contact edge. These results highlight the importance of contact thickness to such organic transistors and reveal that semiconductor morphology should be considered in designing devices with minimal contact effects. [ABSTRACT FROM PUBLISHER]

A theoretical analysis of the carrier mobility in organic transistors is presented. We noticed that the assumption of zero potential at open/quasi-free surface may cause a large deviation of the areal charge density in the organic film, greater in thinner-film transistors. Taking into account this effect, the effective mobility is obtained using the Kubo-Greenwood integral, which provides the total conductivity in the band and thus in the whole organic film. The mobility is studied with respect to gate voltage and temperature, for various disorder and transport diffusivity levels, enabling a better insight of the carrier mobility in organic transistors. [ABSTRACT FROM AUTHOR]

Charge Carrier Mobility: Precise Extraction of Charge Carrier Mobility for Organic Transistors (Adv. Funct. Keywords: mobility; organic transistors; parameter extraction; reliability EN mobility organic transistors parameter extraction reliability 1 1 1 05/18/20 20200515 NES 200515 Charge carriers (electrons and holes) transport in between the source and drain electrodes in an organic transistor, which is the building block of organic circuits. Mobility, organic transistors, parameter extraction, reliability. [Extracted from the article]

Investigates the effect of low frequency excess noise associated to gate-induced floating body on partially depleted silicon-on-insulator metal oxide semiconductor field-effect transistor with ultrathin gate oxide. Gate tunnelling; Saturation regime; Drain voltage.

The reliability of mobility has come to be a critical issue to the development of new electronics especially for organic electronics, since mobility is typically extracted from field‐effect transistors containing various extrinsic effects and overestimation is popular in the literature. Recently, this issue is emphasized and a reliability factor (r) is proposed by pioneers to gauge the mobility reported. Albeit many factors discussed, how much the extrinsic effects influence r remains unrevealed and a facile solution by using organic transistors is still lacking. Here, it is shown that the widely used extraction method based on the saturation transfer characteristics is sensitive to contact effect and temperature with r dropping to 43%, indeed leading to large mobility overestimation. By contrast, the linear‐regime methods are more reliable particularly the Y‐function method that demonstrates great reliability (r ≈ 100%) even for short‐channel transistors at ultralow temperatures. In addition, operating in saturation regime induces ambipolar conduction further deteriorating reliability if contact doping is absent. High Schottky barriers, on the other side, distort device characteristics making extraction impossible. The results of this study reveal that, aside from device optimizations, selecting a right method is essential for reliable and precise evaluation of the carrier mobility by using organic transistors. This paper systematically addresses the essential effects on the mobility extraction reliability. The effects related to specific dielectric capacitance, operating regime, channel length, temperature, ambipolar conduction, and Schottky barrier are examined in a quantitative way. The results of this study show that, aside from device optimizations, selecting a proper extraction method is important to reliable mobility evaluation using organic transistors. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various articles within the issue on topics including integrated circuits, optical devices and photonics.