Electrical characterization and modelling of lateral DMOS transistor:investigation of capacitances and hot-carrier impact

With the work reported in this manuscript we have essentially contributed to the electrical characterization and modelling of high voltage MOSFETs, more particularly DMOS architectures such as X-DMOS and L-DMOS able to sustain voltages ranging from 30V to 100V. The technology information and the investigated devices have been kindly provided by AMIS, Belgium (former Alcatel Microelectronics). In general, all the initial defined targets in term of the orientation of our work, as defined in the introduction chapter, have been maintained along the progress of the work. However, sometimes, based on the obtained results we have decided to pay more attention to some less explored topics such as the hot carrier impact of DMOS capacitances and the combined effect of stress and temperature, which initially were not among the planned activities. However, we believe that we have contributed to some of the planned targets. We experimentally validated the concept of intrinsic drain voltage; a modeling concept dedicated to the modeling of HV MOSFET and demonstrated its usefulness for the DC and AC modelling of HV devices. We proposed an original mathematical yet quasi-empirical formulation for the bias-dependent drift series resistance of DMOS transistor, which is very accurate for modelling all the regimes of operation of the high voltage device. We combined for the first time such a model with EKV low voltage MOSFET model developed at EPFL. We also have reported on models for the capacitances of high voltage devices at two levels: equivalent circuits for small signal operation based on VK-concept and large signal charge-based models. These models capture the main physical charge distribution in the device but they are less adapted for fast circuit simulation. In the field of device reliability, we have originally contributed to the investigation of hot carrier effects on DC and AC characteristics of DMOS transistors, with key emphasis on the degradation of transistor capacitances and the influence of the temperature. At our knowledge, our work reported in this chapter is among the first reports existing in this field. We have essentially shown that the monitoring of capacitance degradation if mandatory for a deep understanding of the degradation mechanisms and, in conjunction with DC parameter degradation, could offer correct insights for reliability issues. Even more, we have shown situations (by comparing two fundamental types of stresses) when the capacitance degradation method by HC is much more sensitive than DC parameter degradation method. Of course, some of the combined stress-temperature investigations were too complex to find very coherent explications for all the observed effects but our work stress out the interest and significance of such an approach for defining the SOA of high voltage devices, in general. Overall, our work can be considered as placed at the interface between electrical characterization and modelling of high voltage devices emerging from conventional low voltage CMOS technology, continuing the research tradition in the field established at the Electronics laboratory (LEG) of EPF Lausanne

Large-signal multi-tone time domain waveform measurement system with broadband active load impedance control

This thesis presents a novel large-signal, multi-tone, time domain waveform measurement and engineering system, which builds upon existing large-signal measurement approaches. The presented system allows for a more considered, and scientific process to be adopted in the design of modern day communications systems. The ultimate aim of this work is to reduce the need for an iterative design approach by providing a measurement system that offers detailed information about a device or circuit without the need for prototyping, it is hoped that such an approach will one day lead to a 'right first time' design approach by allowing ultra-rapid data collection with measurements conducted in realistic environments while employing realistic stimuli. The main contributions to the field of research come in two areas firstly developments that allow for accurate time domain measurement of complex modulated signals using commercially available equipment and secondly in the area of active impedance control, where novel developments were made allowing active control of impedance across a modulated bandwidth. The first research area addressed is the fundamental difficulty in sampling multi-tone waveforms, where the main achievements have been the realisation of a novel frequency-folded and interleaved sampling approach. This approach, with appropriate time-alignment and averaging allows the efficient collection of high-quality vectoral information for all significant distortion terms, for all bands of interest. This means that for the first time off-the-shelf sampling oscilloscopes with limited memory depth can be used capture multi-tone signals in sufficient detail to observe all critical device performance. The second area of research investigated suitable impedance control architectures. Measurement of large-signal multi-tone information is only useful if the broadband impedance environment can also be controlled, only then can we allow a full understanding of the device, and provide the fundamental ability to engineer waveforms for optimum device performance. The main achievement in this area was the development and realisation of a novel architecture that allows active impedance control over a modulated bandwidth

Cutting Edge Nanotechnology

The main purpose of this book is to describe important issues in various types of devices ranging from conventional transistors (opening chapters of the book) to molecular electronic devices whose fabrication and operation is discussed in the last few chapters of the book. As such, this book can serve as a guide for identifications of important areas of research in micro, nano and molecular electronics. We deeply acknowledge valuable contributions that each of the authors made in writing these excellent chapters

Intelligent Circuits and Systems

ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.　 This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering