There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Science and technologies based on terahertz frequency electromagnetic radiation (100 GHz–30 THz) have developed rapidly over the last 30 years. For most of the 20th Century, terahertz radiation, then referred to as sub-millimeter wave or far-infrared radiation, was mainly utilized by astronomers and some spectroscopists. Following the development of laser based terahertz time-domain spectroscopy in the 1980s and 1990s the field of THz science and technology expanded rapidly, to the extent that it now touches many areas from fundamental science to 'real world' applications. For example THz radiation is being used to optimize materials for new solar cells, and may also be a key technology for the next generation of airport security scanners. While the field was emerging it was possible to keep track of all new developments, however now the field has grown so much that it is increasingly difficult to follow the diverse range of new discoveries and applications that are appearing. At this point in time, when the field of THz science and technology is moving from an emerging to a more established and interdisciplinary field, it is apt to present a roadmap to help identify the breadth and future directions of the field. The aim of this roadmap is to present a snapshot of the present state of THz science and technology in 2017, and provide an opinion on the challenges and opportunities that the future holds. To be able to achieve this aim, we have invited a group of international experts to write 18 sections that cover most of the key areas of THz science and technology. We hope that The 2017 Roadmap on THz science and technology will prove to be a useful resource by providing a wide ranging introduction to the capabilities of THz radiation for those outside or just entering the field as well as providing perspective and breadth for those who are well established. We also feel that this review should serve as a useful guide for government and funding agencies.

The 2016 terahertz science and technology roadmap

This survey deals with 1/f noise in homogeneous semiconductor samples. A distinction is made between mobility noise and number noise. It is shown that there always is mobility noise with an /spl alpha/ value with a magnitude in the order of 10/sup -4/. Damaging the crystal has a strong influence on /spl alpha/, /spl alpha/ may increase by orders of magnitude. Some theoretical models are briefly discussed none of them can explain all experimental results. The /spl alpha/ values of several semiconductors are given. These values can be used in calculations of 1/f noise in devices. >

1/f Noise Sources

There can be little doubt that the Monte Carlo method for semiconductor device simulation has enormous power as a research tool. It represents a detailed physical model of the semiconductor material(s), and provides a high degree of insight into the microscopic transport processes. However, if the authority ascribed to Monte Carlo models of devices at 1/spl mu/m feature size is to be maintained for devices below O.1/spl mu/m, modelling of the fundamental physics must be further improved. And if the Monte Carlo method is to be successful as a semiconductor device design tool, the device model must be made more realistic. Success in the industrial sector depends on this, but also on achieving fast run-times optimisation - where the scope and need for ingenuity is now greatest.

The Monte Carlo method for semiconductor device simulation

A system includes a semiconductor device. The semiconductor device includes a first single crystal silicon layer comprising first transistors, first alignment marks, and at least one metal layer overlying the first single crystal silicon layer, wherein the at least one metal layer comprises copper or aluminum more than other materials; and a second single crystal silicon layer overlying the at least one metal layer. The second single crystal silicon layer comprises a plurality of second transistors arranged in substantially parallel bands. Each of a plurality of the bands comprises a portion of the second transistors along an axis in a repeating pattern.

System comprising a semiconductor device and structure

We have experimentally analyzed the leakage mechanism and device degradations caused by the Fowler-Nordheim (F-N) and hot carrier stresses for the recently developed dynamic random-access memory cell transistors with deeply recessed channels. We have identified the important differences in the leakage mechanism between saddle fin (S-Fin) and recess channel array transistor (RCAT). These devices have their own respective structural benefits with regard to leakage current. Therefore, we suggest guidelines with respect to the optimal device structures such that they have the advantages of both S-Fin and RCAT structures. With these guidelines, we propose a new recess-FinFET structure that can be realized by feasible manufacturing process steps. The structure has the side-gate form only in the bottom channel region. This enhances the characteristics of the threshold voltage (VTH), ON/OFF currents, and the retention time distributions compared with the S-Fin structure introduced recently.

A Proposal on an Optimized Device Structure With Experimental Studies on Recent Devices for the DRAM Cell Transistor

Introduction - Electron transport in the 3D k-space: The Boltzmann transport equation and its projection onto spherical harmonics - Device simulation - Band structure and scattering mechanisms - Results - Transport in a quasi 2D hole gas: Coordinate systems and systems of equation - Efficient k  p SE solver - Efficient 2D k-space discretization and non-linear interpolation schemes - Deterministic solver for the multisubband stationary BTE - Poisson equation - Iteration methods - Results - References

Deterministic Solvers for the Boltzmann Transport Equation

The numerical properties of a deterministic Boltzmann equation solver based on a spherical harmonics expansion of the distribution function are analyzed and improved. A fully coupled discretization scheme of the Boltzmann and Poisson equations is proposed, where stable equations are obtained based on the H-transformation. It is explicitly shown that the resultant Jacobian matrix for the zeroth order component has property M for a first order expansion, which improves the stability even of higher order expansions. The detailed dependence of the free-streaming operator and the scattering operator on the electrostatic potential is exactly considered in the Newton-Raphson scheme. Therefore, convergence enhancement is achieved compared with previous Gummel-type approaches. This scheme is readily applicable to small-signal and noise analysis. As numerical examples, simulation results are shown for a silicon n+nn+ structure including a magnetic field, an SOI NMOSFET and a SiGe HBT.

A fully coupled scheme for a Boltzmann-Poisson equation solver based on a spherical harmonics expansion

Atmospheric deposition of persistent organic pollutants to the East Rongbuk Glacier in the Himalayas

https://iopscience.iop.org/article/10.1149/2.0181907jss/pdf

Sung-Min Hong

Papers

A Proposal on an Optimized Device Structure With Experimental Studies on Recent Devices for the DRAM Cell Transistor

Deterministic Solvers for the Boltzmann Transport Equation

A fully coupled scheme for a Boltzmann-Poisson equation solver based on a spherical harmonics expansion

Atmospheric deposition of persistent organic pollutants to the East Rongbuk Glacier in the Himalayas

Simulation Study of Enhancement Mode Multi-Gate Vertical Gallium Oxide MOSFETs