This book presents a hierarchy of macroscopic models for semiconductor
devices, studying three classes of models in detail: isentropic
drift-diffusion equations, energy-transport models, and quantum
hydrodynamic equations. The derivation of each, including physical
discussions, is shown. Numerical simulations for modern semiconductor
devices are performed, showing the particular features of each. The
author develops modern analytical techniques, such as positive solution
methods, local energy methods for free-boundary problems and entropy
methods.