As we settle into this second decade of the 21st century, it is evident that the advances in microelectronics have truly revolutionized our day-to-day lifestyle. The growth of microelectronics itself has been driven, and in turn is calibrated by, the growth in density of transistors on a single integrated circuit, a growth that has come to be known as Moore's Law. Considering that the first transistor appeared only at the middle of the last century, it is remarkable that billions of transistors can now appear on a single chip. The technology is built upon semiconductors, materials in which the band gap has been engineered for special values suitable to the particular application. This book, written specifically for a one-semester course for graduate students, provides a thorough understanding of the key solid state physics of semiconductors and prepares readers for further advanced study, research and development work in semiconductor materials and applications. The book describes how quantum mechanics gives semiconductors unique properties that enabled the microelectronics revolution, and sustain the ever-growing importance of this revolution. Including chapters on electronic structure, lattice dynamics, electron-phonon interactions and carrier transport, it also discusses theoretical methods for computation of band structure, phonon spectra, the electron-phonon interaction and transport of carriers.