Hf Based High K Dielectrics

In this work, the reliability of HfO2 (hafnium oxide) with poly gate and dual metal gate electrode (Ru–Ta alloy, Ru) was investigated. Hard breakdown and soft breakdown, particularly the Weibull slopes, were studied under constant voltage stress. Dynamic stressing has also been used. It was found that the combination of trapping and detrapping contributed to the enhancement of the projected lifetime. The results from the polarity dependence studies showed that the substrate injection exhibited a shorter projected lifetime and worse soft breakdown behavior, compared to the gate injection. The origin of soft breakdown (first breakdown) was studied and the results suggested that the soft breakdown may be due to one layer breakdown in the bilayer structure (HfO2/SiO2: 4 nm/4 nm). Low Weibull slope was in part attributed to the lower barrier height of HfO2 at the interface layer. Interface layer optimization was conducted in terms of mobility, swing, and short channel effect using deep submicron MOSFET devices.

"The book comprehensively covers all the current and the emerging areas of the physics and the technology of high permittivity gate dielectric materials, including, topics such as MOSFET basics and characteristics, hafnium-based gate dielectric materials, Hf-based gate dielectric processing, metal gate electrodes, flat-band and threshold voltage tuning, channel mobility, high-k gate stack degradation and reliability, lanthanide-based high-k gate stack materials, ternary hafnia and lanthania based high-k gate stack films, crystalline high-k oxides, high mobility substrates, and parameter extraction. Each chapter begins with the basics necessary for understanding the topic, followed by a comprehensive review of the literature, and ultimately graduating to the current status of the technology and our scientific understanding and the future prospects." .

In this work, the reliability of HfO2 (hafnium oxide) with poly gate and dual metal gate electrode (Ru–Ta alloy, Ru) was investigated. Hard breakdown and soft breakdown, particularly the Weibull slopes, were studied under constant voltage stress. Dynamic stressing has also been used. It was found that the combination of trapping and detrapping contributed to the enhancement of the projected lifetime. The results from the polarity dependence studies showed that the substrate injection exhibited a shorter projected lifetime and worse soft breakdown behavior, compared to the gate injection. The origin of soft breakdown (first breakdown) was studied and the results suggested that the soft breakdown may be due to one layer breakdown in the bilayer structure (HfO2/SiO2: 4 nm/4 nm). Low Weibull slope was in part attributed to the lower barrier height of HfO2 at the interface layer. Interface layer optimization was conducted in terms of mobility, swing, and short channel effect using deep submicron MOSFET devices.

A state-of-the-art overview of high-k dielectric materials for advanced field-effect transistors, from both a fundamental and a technological viewpoint, summarizing the latest research results and development solutions. As such, the book clearly discusses the advantages of these materials over conventional materials and also addresses the issues that accompany their integration into existing production technologies. Aimed at academia and industry alike, this monograph combines introductory parts for newcomers to the field as well as advanced sections with directly applicable solutions for experienced researchers and developers in materials science, physics and electrical engineering.

The drive toward smaller and smaller electronic componentry has huge implications for the materials currently being used. As quantum mechanical effects begin to dominate, conventional materials will be unable to function at scales much smaller than those in current use. For this reason, new materials with higher electrical permittivity will be requ

This issue covers in detail all aspects of the physics and the technology of high dielectric constant gate stacks, including high mobility substrates, high dielectric constant materials, processing, metals for gate electrodes, interfaces, physical, chemical, and electrical characterization, gate stack reliability, and DRAM and non-volatile memories.

The main goal of this book is to review at the nano and atomic scale the very complex scientific issues that pertain to the use of advanced high dielectric constant (high-k) materials in next generation semiconductor devices. One of the key obstacles to integrate this novel class of materials into Si nano-technology are the electronic defects in high-k dielectrics. It has been established that defects do exist in high-k dielectrics and they play an important role in device operation. The unique feature of this book is a special focus on the important issue of defects. The subject is covered from various angles, including silicon technology, processing aspects, materials properties, electrical defects, microstructural studies, and theory. The authors who have contributed to the book represents a diverse group of leading scientists from academic, industrial and governmental labs worldwide who bring a broad array of backgrounds (basic and applied physics, chemistry, electrical engineering, surface science, and materials science). The contributions to this book are accessible to both expert scientists and engineers who need to keep up with leading edge research, and newcomers to the field who wish to learn more about the exciting basic and applied research issues relevant to next generation device technology.