The compelling demand for higher performance and lower power consumption in electronic systems is the main driving force of the electronics industry's quest for devices and/or architectures based on new materials. Here, we provide a review of electronic devices based on two-dimensional materials, outlining their potential as a technological option beyond scaled complementary metal-oxide-semiconductor switches. We focus on the performance limits and advantages of these materials and associated technologies, when exploited for both digital and analog applications, focusing on the main figures of merit needed to meet industry requirements. We also discuss the use of two-dimensional materials as an enabling factor for flexible electronics and provide our perspectives on future developments.

Electronics based on two-dimensional materials

Brownian motors: noisy transport far from equilibrium

International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

In systems possessing spatial or dynamical symmetry breaking, Brownian motion combined with unbiased external input signals, deterministic and random alike, can assist directed motion of particles at submicron scales. In such cases, one speaks of ``Brownian motors.'' In this review the constructive role of Brownian motion is exemplified for various physical and technological setups, which are inspired by the cellular molecular machinery: the working principles and characteristics of stylized devices are discussed to show how fluctuations, either thermal or extrinsic, can be used to control diffusive particle transport. Recent experimental demonstrations of this concept are surveyed with particular attention to transport in artificial, i.e., nonbiological, nanopores, lithographic tracks, and optical traps, where single-particle currents were first measured. Much emphasis is given to two- and three-dimensional devices containing many interacting particles of one or more species; for this class of artificial motors, noise rectification results also from the interplay of particle Brownian motion and geometric constraints. Recently, selective control and optimization of the transport of interacting colloidal particles and magnetic vortices have been successfully achieved, thus leading to the new generation of microfluidic and superconducting devices presented here. The field has recently been enriched with impressive experimental achievements in building artificial Brownian motor devices that even operate within the quantum domain by harvesting quantum Brownian motion. Sundry akin topics include activities aimed at noise-assisted shuttling other degrees of freedom such as charge, spin, or even heat and the assembly of chemical synthetic molecular motors. This review ends with a perspective for future pathways and potential new applications.

/pdf/artificial-brownian-motors-controlling-transport-on-the-1553poaezw.pdf

Artificial Brownian motors: Controlling transport on the nanoscale

https://www.physik.uni-augsburg.de/theo1/hanggi/Papers/213.pdf

Driven quantum tunneling

Photon-assisted tunneling (PAT), long restricted to transport in superconducting junctions1, has recently emerged in transport in semiconductor superlattices and nanostructures in the presence of high frequency fields2,3,4,5,6,7,8 The full character of PAT, however, has not been experimentally established.

Photon-Assisted Electric Field Domains and Multiphoton-Assisted Tunneling in Antenna Coupled Semiconductor Superlattices

along with the measured static-noise-margin (SNM) curves, and the scaling trend of SRAM density and performance. The SRAM design continues to maintain 2× scaling in bit density and 15% improvement in performance per generation. Patterning enhancement techniques and 193nm immersion lithography are used for critical layers to mitigate process variations and enable aggressive design rule scaling. To determine the minimum operating voltage (VCCmin) of a 6T SRAM cell in a large cache design, variation analyses of SNM, dynamic read stability and writability with the random transistor threshold voltage variation (σVT, random) have typically been applied [3,4]. While the σVt, random is still the dominant source of variation when determining the dielevel VCCmin, a large variety of systematic process variations [5] have become significant contributors to the wafer-level die VCCmin distribution. To ensure sufficient SRAM yield in high-volume manufacturing, a methodology described in Fig. 27.1.2 is applied to model the wafer-level VCCmin distribution, where both random and systematic process variations are modeled. The systematic process variation at the wafer-level is modeled as the systematic transistor threshold voltage variation, σVt, system, which can be directly characterized by Vt measurements in the bitcell. Comparison of the measured wafer-level VCCmin distribution with simulation is shown in Fig. 27.1.2. With the systematic VT variation modeled in the simulation, the statistical VCCmin distribution at the high percentile, critical to the yield projection, is more adequately modeled by simulation. Analysis of read-versus-write VCCmin distribution also helps bitcell optimization for optimal manufacturing yield with balanced read and write VCCmin.

Uddalak Bhattacharya

Papers

Photon-Assisted Electric Field Domains and Multiphoton-Assisted Tunneling in Antenna Coupled Semiconductor Superlattices

32nm High-κ Metal-Gate CMOS with Integrated Power Management