Physics and Technology of Silicon Carbide Devices

Recently, some SiC power devices such as Schottky-barrier diodes (SBDs), metal-oxide-semiconductor field-effect-transistors (MOSFETs), junction FETs (JFETs), and their integrated modules have come onto the market. However, to stably supply them and reduce their cost, further improvements for material characterizations and those for device processing are still necessary. This book abundantly describes recent technologies on manufacturing, processing, characterization, modeling, and so on for SiC devices. In particular, for explanation of technologies, I was always careful to argue physics underlying the technologies as much as possible. If this book could be a little helpful to progress of SiC devices, it will be my unexpected happiness

Feature Papers in Electronic Materials Section

This book entitled "Feature Papers in Electronic Materials Section" is a collection of selected papers recently published on the journal Materials, focusing on the latest advances in electronic materials and devices in different fields (e.g., power- and high-frequency electronics, optoelectronic devices, detectors, etc.). In the first part of the book, many articles are dedicated to wide band gap semiconductors (e.g., SiC, GaN, Ga2O3, diamond), focusing on the current relevant materials and devices technology issues. The second part of the book is a miscellaneous of other electronics materials for various applications, including two-dimensional materials for optoelectronic and high-frequency devices. Finally, some recent advances in materials and flexible sensors for bioelectronics and medical applications are presented at the end of the book

Crystal Growth, Characterization and Fabrication of CDZNTE-Based Nuclear Detectors

In today\u27s world, nuclear radiation is seeing more and more use by humanity as time goes on. Nuclear power plants are being built to supply humanity\u27s energy needs, nuclear medical imaging is becoming more popular for diagnosing cancer and other diseases, and control of weapons-grade nuclear materials is becoming more and more important for national security. All of these needs require high-performance nuclear radiation detectors which can accurately measure the type and amount of radiation being used. However, most current radiation detection materials available commercially require extensive cooling, or simply do not function adequately for high-energy gamma-ray emitting nuclear materials such as uranium and plutonium. One of the most promising semiconductor materials being considered to create a convenient, field-deployable nuclear detector is cadmium zinc telluride (CdZnTe, or CZT). CZT is a ternary semiconductor compound which can detect high-energy gamma-rays at room temperature. It offers high resistivity (10^10 Ohm-cm), a high band gap (1.55 eV), and good electron transport properties, all of which are required for a nuclear radiation detector. However, one significant issue with CZT is that there is considerable difficulty in growing large, homogeneous, defect-free single crystals of CZT. This significantly increases the cost of producing CZT detectors, making CZT less than ideal for mass-production. Furthermore, CZT suffers from poor hole transport properties, which creates significant problems when using it as a high-energy gamma-ray detector. In this dissertation, a comprehensive investigation is undertaken using a successful growth method for CZT developed at the University of South Carolina. This method, called the solvent-growth technique, reduces the complexity required to grow detector-grade CZT single crystals. It utilizes a lower growth temperature than traditional growth methods by using Te as a solvent, while maintaining the advantages of crystal homogeneity of other modern CZT growth techniques. However, information about crystals grown with this method has not been undertaken in a comprehensive way thus far. In this work, Cd(0.9)Zn(0.1)Te is grown using the solvent-growth method using zone-refined precursor materials loaded into carbon-coated quartz ampoules. Ampoules were sealed and crystal growth was performed using crystal growth furnaces built in-house at USC. Ingots 1-2 in diameter produced using the solvent-growth method were wafered, processed, and polished for characterization. Semiconductor characterization is performed on the CZT crystals to determine band gap, elemental stoichiometry, and electrical resistivity. Surface modification studies were undertaken to determine if surface leakage current can be reduced using sulfur passivation. XPS studies were used to confirm the effects of passivation on the surface states, and electrical characterization was performed to measure the effects of passivation on the CZT crystals. Deep-level and surface defect studies were conducted on the CZT samples to determine the type and intensity of defects present in the crystals which may affect detector performance. Finally, nuclear detectors were fabricated and characterized using analog and digital radiation detection systems to measure their performance and energy resolution

Solar Cells

Over the last decade, photovoltaic (PV) technology has shown the potential to become a major source of power generation for the world - with robust and continuous growth even during times of financial and economic crisis. That growth is expected to continue in the years ahead as worldwide awareness of the advantages of PV increases. However, cost remains as the greatest barrier to further expansion of PV-generated power, and therefore cost reduction is the prime goal of the PV and solar cell investigation. This book intends to contribute to such a purpose by covering a wide range of modern research topics in the solar cell physics and technology fields. The already established -1st generation- silicon solar cell technology, the 2nd generation thin film and the 3rd generation dye sensitized solar cells, including new technologies with very high perspectives for reducing the cost of solar electricity such as CZTS, organic polymer and tandem solar cells based on III-V compounds -under concentrated sunlight- are studied in this book by experts in the field from around the world. At the end, two chapters are also dedicated to the systems engineering, providing a complete PV energy research and application perspectives panoram

The effect of crystal growth conditions and surface treatment on CdZnTe bulk single crystal

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de Materiales. Fecha de lectura: 17-06-201

Wide Bandgap Based Devices: Design, Fabrication and Applications, Volume II

Wide bandgap (WBG) semiconductors are becoming a key enabling technology for several strategic fields, including power electronics, illumination, and sensors. This reprint collects the 23 papers covering the full spectrum of the above applications and providing contributions from the on-going research at different levels, from materials to devices and from circuits to systems

Low Temperature Silicon Oxide and Fluorinated Silicon Oxide Films Prepared by Plasma-Enhanced Chemical Vapor Deposition Using Disilane as Silicon Precursor.

The deposition and characterization of the silicon oxide and fluorinated silicon oxide films, as interlevel dielectrics in microelectronics devices, prepared by plasma enhanced chemical vapor deposition at low substrate temperature using \rm Si\sb2H\sb6 as silicon precursor are studied. The film deposition is limited by the mass transport regime, resulting in nearly temperature independent deposition rate. The characteristics for the silicon oxide films deposited at 120\sp\circC show that the film etch rate is comparable to that obtained by TEOS-based PECVD at 400\sp\circC and the leakage current is comparable to that of the films deposited at 350\sp\circC with conventional SiH\sb4 precursor. It also shows that the as-deposited silicon oxide films have 9.4% increase in the film density compared to the thermal silicon oxide films, resulting in the Si-O-Si bridging bond angle of 138\sp\circ. The post-metallization annealing in forming gas ambient at 400\sp\circC rather than post-deposition annealing at high temperatures in N\sb2 is the most effective way to reduce both the oxide charge and interface trap densities, especially for devices fabricated on the native oxide-free surface. For the fluorinated silicon oxide film deposition, the optimum gas flow ratio of CF\sb4, as fluorine precursor, to \rm Si\sb2H\sb6 is observed to be in the range of 8-10. The films deposited at a flow ratio of 10 give the film a dielectric constant of 4.25 which is 12% lower than 4.88 obtained for the fluorine-free silicon oxide films. The addition of fluorine into Si-O network helps not only in reducing the effective oxide charges to as low as 1/6 of the value for the fluorine-free silicon oxide films, but also improves the breakdown property by significantly reducing early failures, resulting in the average dielectric breakdown field strength of 8.91 MV/cm. These films have a strong potential for the use as interlayer dielectric material making available a low temperature and high quality film deposition process for submicron device fabrication in the microelectronics industry

Institute of Ion Beam Physics and Materials Research: Annual Report 2002

Summary of the scientific activities of the institute in 2002 including selected highlight reports, short research contributions and an extended statistics overview