Parallel semiconductor device simulation: from power to 'atomistic' devices

This paper discusses various aspects of the parallel simulation of semiconductor devices on mesh connected MIMD platforms with distributed memory and a message passing programming paradigm. We describe the spatial domain decomposition approach adopted in the simulation of various devices, the generation of structured topologically rectangular 2D and 3D finite element grids and the optimisation of their partitioning using simulated annealing techniques. The development of efficient and scalable parallel solvers is a central issue of parallel simulations and the design of parallel SOR, conjugate gradient and multigrid solvers is discussed. The domain decomposition approach is illustrated in examples ranging from `atomistic' simulation of decanano MOSFETs to simulation of power IGBTs rated for 1000 V

RTS amplitudes in decanano n-MOSFETs with conventional and high-k gate stacks

Low frequency (LF) noise in MOSFETs has been a topic of interest to both academia and industry in recent years. It is becoming a major concern for analogue circuit performance, DRAM operation, and will eventually impact critically upon the reliability of digital logic especially as devices continue to scale towards nano dimensions. Random telegraph signals (RTS) caused by the capture and emission of carriers in traps at the Si/SiO/sub 2/ interface have been posited as a major component of low frequency noise in semiconductor devices. The change in the drain current associated with trapping events in defect states is usually referred to as the RTS amplitude. The magnitude of the RTS amplitude is largest in the subthreshold regime at lower gate voltages and is reduced in the strong inversion regime as mobile charge in the inversion layer increasingly screens out the electrostatic influence of the trapped charge. We study the magnitude of the RTS amplitudes in nano-CMOS devices with conventional and high- gate stacks. Traps at the front and back gate dielectric interfaces, as well as traps in the body of the dielectric are considered. The impact of poly gate depletion is also taken into account

Productivity in Small Business: an analysis using African data

Labor and floorspace cost functions are derived for small business trade. Relationships are proposed between average volume of labor or average floorspace per establishment on the one hand, and average size per establishment, average rental paid, percentage selling space, and indicators of business type and location on the other. Promising estimation results are reported using South African data of 1979/1980. The method however is not restricted to the South African case. A productivity business support system can be developed providing productivity standards for any area in the small (service) business. An analysis similar to the one presented here, but relating to the area in question, should precede the development of such a system

Labour productivity, economies of scale and opening time in large retail establishments

Differences in labour productivity are dealt with for large French retail establishments. Influences of scale, weekly opening time, assortment composition, wage rate and share of counter service are considered. The relationship used is a result of analyses in the field of small retail establishments

Entrepreneurship, Economic Growth and Policy in Emerging Economies

Entrepreneurship has emerged as an important element in the organization of economies. This emergence did not occur simultaneously in all developed countries. Differences in growth rates are often attributed to differences in the speed with which countries embrace entrepreneurial energy. This led to the political mandate to promote entrepreneurship. Hence, a clear and organized view is needed of what the determinants and consequences of entrepreneurship are. The present contribution tries to provide this view with a particular view on emerging economies. Entrepreneurship, its drivers and its consequences can be best understood using the model of the Entrepreneurial Economy which explains the functioning of the modern economy. This model differs from that of the earlier Managed Economy. Policies in emerging economies should aim at combining the two models

De Ondernemerschapseconomie

De overgang van de managed naar de entrepreneurial economie wordt aangetoond met behulp van de relatie tussen de TEA-index (Total Entrepreneurial Activity) en het ontwikkelingsniveau van een economie. Vervolgens wordt met behulp van veertien dimensies het onderscheid tussen de twee economieën besproken

Introduction: economic performance and small business

This paper introduces the special issue of Small business Economics on Performance. The concept of economic performance refers to the degree to which society's resources are being used as efficiently as possible. Where the field of industrial organization has emphasized the influence of market concentration on economic performance, the papers of this special issue zoom in on the link between firm size and economic performance

UTB SOI SRAM cell stability under the influence of intrinsic parameter fluctuation

Intrinsic parameter fluctuations steadily increases with CMOS technology scaling. Around the 90nm technology node, such fluctuations will eliminate much of the available noise margin in SRAM based on conventional MOSFETs. Ultra thin body (UTB) SOI MOSFETs are expected to replace conventional MOSFETs for integrated memory applications due to superior electrostatic integrity and better resistant to some of the sources of intrinsic parameter fluctuations. To fully realise the performance benefits of UTB SOI based SRAM cells a statistical circuit simulation methodology which can fully capture intrinsic parameter fluctuation information into the compact model is developed. The impact on 6T SRAM static noise margin characteristics of discrete random dopants in the source/drain regions and body-thickness variations has been investigated for well scaled devices with physical channel length in the range of 10nm to 5nm. A comparison with the behaviour of a 6T SRAM based on a conventional 35nm MOSFET is also presented

Impact of random dopant induced fluctuations on sub-15nm UTB SOI 6T SRAM cells

The CMOS scaling increases the impact of intrinsic parameter fluctuation on the yield and functionality of SRAM. A statistical circuit simulation framework which can fully capture intrinsic parameter fluctuation information into the compact model has been developed. The impact of discrete random dopants in the source and drain regions on 6T SRAM cells has been investigated for well scaled ultra thin body (UTB) SOI MOSFETs with physical channel length in the range of 10nm to 5nm

A fuzzy soft set theoretic approach to decision making problems

AbstractThe problem of decision making in an imprecise environment has found paramount importance in recent years. A novel method of object recognition from an imprecise multiobserver data has been presented here. The method involves construction of a Comparison Table from a fuzzy soft set in a parametric sense for decision making