The primary goal of this book is to provide a sound understanding of wide bandgap Silicon Carbide (SiC) power semiconductor device simulation using Silvaco© ATLAS Technology Computer Aided Design (TCAD) software. Physics-based TCAD modeling of SiC power devices can be extremely challenging due to the wide bandgap of the semiconductor material. The material presented in this book aims to shorten the learning curve required to start successful SiC device simulation by providing a detailed explanation of simulation code and the impact of various modeling and simulation parameters on the simulation results. Non-isothermal simulation to predict heat dissipation and lattice temperature rise in a SiC device structure under switching condition has been explained in detail. Key pointers including runtime error messages, code debugging, implications of using certain models and parameter values, and other factors beneficial to device simulation are provided based on the authors' experience while simulating SiC device structures. This book is useful for students, researchers, and semiconductor professionals working in the area of SiC semiconductor technology. Readers will be provided with the source code of several fully functional simulation programs that illustrate the use of Silvaco© ATLAS to simulate SiC power device structure, as well as supplementary material for download.

With superior material properties, Silicon carbide (SiC) power devices show great potential for high-power density, high temperature switching applications. Among all the power device structures, SiC MOSFET attracts the most attention because of its high gate input impedance, simple gate control and fast switching speed. However, low inversion channel mobility, high near-interface state density close to the conduction band edge, questionable oxide reliability as well as theoretical limit on the device figure-of-merit still remain to be significant challenges to the development of SiC power MOSFETs. In this dissertation, all of the above challenges are addressed from various approaches. First, simulations on the super-junction structure show that the unipolar theoretical limit of SiC can be broken even with the state-of-the-art processing technologies. An easy-to-implement analytical model is developed for calculations of the blocking voltage, specific on-resistance and charge imbalance effects of 4H-SiC super-junction devices. This model is validated by extensive numerical simulations with a large variety of device parameters. Device design and optimization using this model are also presented. Second, a wafer-level Hall mobility measurement technique is developed to measure channel mobility more accurately, more efficiently and more cost-effectively. Device characterization and development are much more convenient by using this technique. With this method, further explorations of interactions between interface traps and channel carriers as well as device degradation mechanisms become possible. Third, reliability of SiO2 on 4H-SiC is characterized with time dependent dielectric breakdown (TDDB) measurements at various temperatures and electric fields. Lifetime prediction to normal operation conditions suggests that the oxide on SiC has a characteristic lifetime of 10 years at 375° C if the oxide electric field is kept below 4.6 MV/cm. The observed excellent reliability data contradict the widespread belief that the oxide on SiC is intrinsically limited by its physical properties. Detailed discussions are provided to re-examine the arguments leading to the misconception.

This volume contains the Proceedings of the International Conference on Simulation of Semiconductor Devices and Processes, SISPAD 01, held on September 5–7, 2001, in Athens. The conference provided an open forum for the presentation of the latest results and trends in process and device simulation. The trend towards shrinking device dimensions and increasing complexity in process technology demands the continuous development of advanced models describing basic physical phenomena involved. New simulation tools are developed to complete the hierarchy in the Technology Computer Aided Design simulation chain between microscopic and macroscopic approaches. The conference program featured 8 invited papers, 60 papers for oral presentation and 34 papers for poster presentation, selected from a total of 165 abstracts from 30 countries around the world. These papers disclose new and interesting concepts for simulating processes and devices.

Silicon carbide as a semiconductor material possesses several significant physical properties which make it superior for applications to high power devices. This report documents the efforts to develop, demonstrate, and optimize the design and fabrication methodologies for the realization of power vertical junction field effect transistors in the 4H-polytype of silicon carbide. Theoretical prediction and modeling simulation, incorporating all the significant SiC specific device physics, are utilized to develop a design methodology which is to ultimately be used for device fabrication. The results illustrate that good agreement between theoretical prediction and accurately modeled simulations can be achieved and enable the forecasting of device performance as a function of temperature, design modification, and variations in material transport characteristics.

The objective of this work was to conduct a modeling study of SiC P-N junction diodes operating under high reverse biased conditions. Analytical models and numerical simulation capabilities were to be developed for self-consistent electro-thermal analysis of the diode current-voltage (I-V) characteristics. Data from GRC indicate that screw dislocations are unavoidable in large area SiC devices, and lead to changes in the SiC diode electrical response characteristics under high field conditions. For example, device instability and failures linked to internal current filamentation have been observed. The physical origin of these processes is not well understood, and quantitative projections of the electrical behavior under high field and temperature conditions are lacking. Thermal calculations for SiC devices have not been reported in the literature either. So estimates or projections of peak device temperatures and power limitations do not exist. This numerical study and simulation analysis was aimed at resolving some of the above issues. The following tasks were successfully accomplished: (1) Development of physically based models using one- and two-dimensional drift-diffusion theory for the transport behavior and I-V characteristics; (2) One- and two-dimensional heat flow to account for internal device heating. This led to calculations of the internal temperature profiles, which in turn, were used to update the electrical transport parameters for a self-consistent analysis. The temperature profiles and the peak values were thus obtainable for a given device operating condition; (3) Inclusion of traps assumed to model the presence of internal screw dislocations running along the longitudinal direction; (4) Predictions of the operating characteristics with and without heating as a function of applied bias with and without traps. Both one and two-dimensional cases were implemented; (5) Assessment of device stability based on the operating characteristics. The presence

This handbook presents the key properties of silicon carbide (SiC), the power semiconductor for the 21st century. It describes related technologies, reports the rapid developments and achievements in recent years, and discusses the remaining challenging issues in the field. The book consists of 15 chapters, beginning with a chapter by Professor W. J. Choyke, the leading authority in the field, and is divided into four sections. The topics include presolar SiC history, vapor-liquid-solid growth, spectroscopic investigations of 3C-SiC/Si, developments and challenges in the 21st century; CVD principles and techniques, homoepitaxy of 4H-SiC, cubic SiC grown on 4H-SiC, SiC thermal oxidation processes and MOS interface, Raman scattering, NIR luminescent studies, Mueller matrix ellipsometry, Raman microscopy and imaging, 4H-SiC UV photodiodes, radiation detectors, and short wavelength and synchrotron X-ray diffraction. This comprehensive work provides a strong contribution to the engineering, materials, and basic science knowledge of the 21st century, and will be of interest to material growers, designers, engineers, scientists, postgraduate students, and entrepreneurs.