Learning outcomes of the course unit
To provide students with in-depth knowledge of the physics of fundamental silicon devices.
Basics of elecron device physics and electromagnetism.
Course contents summary
1) Semiconductors at equilibrium. Mass-action law. fermi-Dirac and Maxwell-Botzmann distributions. Density of sates. Fermi level and pseudo-Fermi levels. Free carriers in semiconductors. Mobility. Saturation velocity. Diffusion current.
2) Metal-semiconductor junction at equilibrium. Image-force barrier lowering. I-V characteristics. Ohmic contacts. Surface effects.
3) PN junction at equilibrium. Debye length. reverse polarization. Capacitance of a reverse-biased junction. Avalance and Zener breakdown. Continuity equations. Sh0cley-Hall-Read generation and recombination. Auger and surface recombination. I-V characteristics. Long-base and short-base diodes. Discussion of the approximations. Generation-recombination currents in forward and reverse bias. Switching transients. Difusion capacitance.
4) Bipolar Junction Transistors. Forward-active region. Base transport factor. Emitter efficiency. BJT switching. Ebers-Moll model. Early effect. Integrated BJTs. Low-current effects. High-injection: Kirk effect, base resistance. Base transit time. Charge-control model. Frequency limitations. PNP transistors.
5) MOS Transistor (MOSFET). Ideal MOS system. Band structure. Accumulation, depletion, inversion, strong inversion. Threshold voltage and body effect. C-V characteristics. Non-ideal MOS systems: oxide and interface charge. Bulk-charge effect. Threshold voltage adjustment. Sub-threshold current. Short- and narrow-channel effects: source/drain charge sharing, drain-induced barrier lowering, sub-surface punch-through. Mobility reduction. Velocity saturation. Short-channel MOSFETs: I-V characteristics and scaling effects. Quasi-2D model of the saturated velocity region. Hot-carrier effects: substrate current and gate current.
R. S. Muller, T. I. Kamins, "Device Electronics for Integrated Circuits", 3rd ed., John Wiley & Sons, 2003.