Ferroelectricity in Doped Hafnium Oxide: Materials, Properties and Devices covers all aspects relating to the structural and electrical properties of HfO2 and its implementation into semiconductor devices, including a comparison to standard ferroelectric materials. The ferroelectric and field-induced ferroelectric properties of HfO2-based films are considered promising for various applications, including non-volatile memories, negative capacitance field-effect-transistors, energy storage, harvesting, and solid-state cooling. Fundamentals of ferroelectric and piezoelectric properties, HfO2 processes, and the impact of dopants on ferroelectric properties are also extensively discussed in the book, along with phase transition, switching kinetics, epitaxial growth, thickness scaling, and more. Additional chapters consider the modeling of ferroelectric phase transformation, structural characterization, and the differences and similarities between HFO2 and standard ferroelectric materials. Finally, HfO2 based devices are summarized. Explores all aspects of the structural and electrical properties of HfO2, including processes, modelling and implementation into semiconductor devices Considers potential applications including FeCaps, FeFETs, NCFETs, FTJs and more Provides comparison of an emerging ferroelectric material to conventional ferroelectric materials with insights to the problems of downscaling that conventional ferroelectrics face

Because of the thermal distribution of electrons in a semiconductor, modern transistors cannot be turned on more sharply than 60 mV of gate voltage for an order of magnitude increase in drain current, the so-called ”Boltzmann tyranny.” This results in an inability to reduce supply voltage, increasing power dissipation in advanced complementary metal- oxide-semiconductor (CMOS) technologies, which threatens the continuation of exponential transistor scaling, also known as Moore’s Law. For this reason, there has been a push in the device research community to invent novel steep swing devices. Negative capacitance in ferroelectric materials was proposed in 2008 by Salahuddin and Datta to provide voltage amplification without needing to design a totally new device. A negative gate capacitance would step-up the applied gate voltage at the semiconductor channel, causing the surface potential to rise faster than the gate voltage, lowering the subthreshold slope below 60 mV/decade. In this work, we attempt to characterize the charge-voltage characteristics of ferroelectrics biased into the negative capacitance regime. Although negative capacitance was experimentally demonstrated in 2010, significant challenges have remained to the practical realization of negative capacitance field-effect transistors (FETs). First, we investigate negative capacitance in an isolated ferroelectric capacitor, and show that the negative capacitance states can be directly observed during switching. Careful analysis of the switching dynamics and phase-field modeling show that the signature of negative capacitance arises from the accelerating growth of domain walls, when an increasing volume fraction of the ferroelectric is depolarized. Although this offers insight into the origins of negative capacitance and help to establish its existence scientifically, it does not address the problem of design. A primary concern is the speed of polarization response, which should be on the order of 1 picosecond or less in order to maintain circuit performance. By analyzing the electromagnetic absorption spectrum of hafnium oxide, the primary candidate for CMOS integration, we are able to estimate the intrinsic delay time as being on the order of 270 fs. Next, in order to maximize the amplification and provide adequate margins for hysteresis-free operation, it is necessary to understand how coupling of the ferroelectric material to the interfacial oxide and semiconductor affects its behavior, and to be able to predict what values of negative capacitance will be realized for a certain material and geometry. This is the problem of capacitance matching, which we aim to solve by using the underlying transistor itself as a charge sensor. By calibrating the drain current to the surface potential in reference devices, we may ascertain the characteristics of the ferroelectric in the negative capacitance devices. This is first carried out with an epitaxial ferroelectric capacitor externally connected to the gate of pre-fabricated Fin-FETs. Following this, we describe the development of an in-house fabrication process using silicon-on-insulator substrates, which allows for simple and efficient process flows. Then, we describe the characterization of these devices, including quasistatic and low-frequency current-voltage (I-V) and capacitance voltage (C-V) measurements, a fast pulse-gated I-V measurement, and an excursion into the memory characteristics of our fabricated FETs. Finally, we discuss efforts to build a computational model of our devices from which we can extract the ferroelectric characteristics needed for predictive design.

Collected Papers of L. D. Landau brings together the collected papers of L. D. Landau in the field of physics. The discussion is divided into the following sections: low-temperature physics (including superconductivity); solid-state physics; plasma physics; hydrodynamics; astrophysics; nuclear physics and cosmic rays; quantum mechanics; quantum field theory; and miscellaneous works. Topics covered include the intermediate state of supraconductors; the absorption of sound in solids; the properties of metals at very low temperatures; and production of showers by heavy particles. This volume is comprised of 100 chapters and begins with Landau's paper on the theory of the spectra of diatomic molecules, followed by his studies on the damping problem in wave mechanics; quantum electrodynamics in configuration space; electron motion in crystal lattices; and the internal temperature of stars. Some of Landau's theories, such as those of stars, energy transfer on collisions, phase transitions, and specific heat anomalies are discussed. Subsequent chapters focus on the structure of the undisplaced scattering line; the transport equation in the case of Coulomb interactions; scattering of light by light; and the origin of stellar energy. This book will be a valuable resource for physicists as well as physics students and researchers.

This book aims to provide information in the ever-growing field of low-power electronic devices and their applications in portable devices, wireless communication, sensor, and circuit domains. Negative Capacitance Field Effect Transistors: Physics, Design, Modeling and Applications discusses low-power semiconductor technology and addresses state-of-the-art techniques such as negative capacitance field effect transistors and tunnel field effect transistors. The book is split into three parts. The first part discusses the foundations of low-power electronics, including the challenges and demands and concepts such as subthreshold swing. The second part discusses the basic operations of negative capacitance field effect transistors (NCFETs) and tunnel field effect transistors (TFETs). The third part covers industrial applications including cryogenics and biosensors with NC-FET. This book is designed to be a one-stop guide for students and academic researchers, to understand recent trends in the IT industry and semiconductor industry. It will also be of interest to researchers in the field of nanodevices such as NC-FET, FinFET, tunnel FET, and device–circuit codesign.

The past two decades have witnessed revolutionary breakthroughs in the understanding of ferroelectric materials, both from the perspective of theory and experiment. This book addresses the paradigmatic shifts in understanding brought about by these breakthroughs, including the consideration of novel fabrication methods and nanoscale applications of these materials, and new theoretical methods such as the effective Hamiltonian approach and density functional theory.

In recent years, there has been an increasing number of issues associated with the continued Metal Oxide Semiconductor Field Effect Transistor (MOSFET) scaling. As feature lengths shrink down to atomic sizes, problems with power consumption, heat dissipation, and quantum effects become more prevalent. The unique properties of ferroelectric materials and their ability to display a negative differential capacitance make them a promising candidate for the use in future transistor technology, and a potential successor to traditional silicon CMOS devices. By placing a ferroelectric material layer in place of the dielectric layer of a MOSFET, it is possible to achieve a subthreshold slope lower than the typical 60 mV/dec limit. This device is called a ferroelectric field effect transistor (FerroFET). In this work, we develop a computational model based on the Landau-Devonshire theory to extract Landau coefficients from polarization-voltage data of a ferroelectric capacitor and simulate the current-voltage behavior of a FerroFET. We computationally demonstrate the gains of FerroFETs over conventional CMOS devices and explore properties of various ferroelectric materials. These FerroFETs have great potential for use in low power applications and could greatly revolutionize the current semiconductor industry.