This clear, student-oriented text is for upper-level or graduate courses covering basic semiconductor physics, physical descriptions of PN-junction diodes, bipolar junction transistors, and MOS Field-effect transistors. The organization is from specific to more general topics with afoundations chapter that reviews critical concepts such as Poisson's Equation, dielectric relaxation, and displacement current. The text progresses toward detailed and often unique coverage: including SPICE modeling of the junction diode, the BJT and MOSFET, ohmic-contact application of the high-lowjunction, and MOS-capacitance crossover.