Review of basic properties of semiconductor materials
 Energy bands in a semiconductor material, dependence of the energy gap on temperature, density of states for the conduction and valence bands;
 Thermodynamic equilibrium: FermiDirac and MaxwellBoltzmann statistics, Fermi level, concentration of electrons and holes;
 Current transport by drift and diffusion of charge carriers, resistivity and sheet resistivity;
 Electrostatic potential in a semiconductor material: nonlinear Poisson equation, Debye length;
 Nonequilibrium conditions: quasiFermi levels, continuity equation for electron and holes, dielectric relaxation time, ShockleyReadHall theory for carrier generation/recombination via defectassisted processes.
pn junction
 Basic structure and device electrostatics under thermodynamic equilibrium: band diagram, builtin potential, electric field profile;
 Forward and reverse bias: band diagram, quasiFermi levels, potential drops and current components along the junction, Shockley idealdiode equation, widebase and narrowbase diodes;
 Generation/recombination currents in the spacecharge region of the junction, high level of injection and parasitic resistances, Gummel plot, temperature dependence of the currentvoltage characteristics of the device;
 Smallsignal model of the pn junction.
Metalsemiconductor junction
 Basic structure and device electrostatics under equilibrium and nonequilibrium conditions;
 Current transport: Schottky's diffusion theory, Bethe's thermionicemission theory, thermionicemissiondiffusion theory;
 Schottky effect;
 Tunneling ohmic contacts;
 Impact of interface states on device operation.
MOS capacitor
 The MOS system: basic structure, working principles, band diagram under thermodynamic equilibrium and in the presence of a gate bias, working regimes of the device;
 Analysis of device electrostatics: calculation of the substrate charge as a function of the surface potential from the solution of the Poisson equation, surface potential and substrate charge as a function of the gate bias, threshold voltage;
 Smallsignal capacitance: dependence on the gate bias (CV curve), lowfrequency, highfrequency and deepdepletion regimes;
 MOS capacitor with ring: split CV, impact of the ring bias on device electrostatics, on threshold voltage and on the CV curve;
 Oxide charge and interface states: impact on device electrostatics and on the CV curve;
 Polysilicon gate: technological benefits, electrostatic drawbacks and impact on the threshold voltage of an nMOS and of a pMOS.
MOSFET
 The longchannel MOSFET: basic structure of the device, working principles, gradualchannel approximation, electrostatic analysis and calculation of the depletion and inversion charge in the channel under subthreshold and stronginversion conditions, general expression for the drain current;
 Currentvoltage characteristics of the longchannel MOSFET above threshold: ohmic, parabolic and saturation regimes, pinchoff condition at the drain, band diagram and quasiFermi levels along the channel, smallsignal model of the transistor, output resistance in the saturation regime and channel length modulation, carrier transit time in the channel, bodyeffect;
 Subthreshold conduction in the longchannel MOSFET: carrier diffusion from source to drain, subthreshold current, subthreshold slope, carrier generation in the channel, transcharacteristics of the transistor;
 Dependence of the electrical characteristics of the device on the oxide thickness, on substrate doping and on temperature, impact of oxide charge and interface states on the drain current, source/drain parasitic resistances and capacitances;
 Shortchannel MOSFET: electrostatics, shortchannel effect, DIBL, velocity saturation along the channel and its impact on the currentvoltage characteristics of the device, early saturation of the drain current due to velocity saturation at the drain;
 MOSFET scaling: constantfield scaling and generalized scaling, scaling tradeoffs and constraints, highk dielectrics, metal gate, ToxWdmax space for the design of scaled MOSFETs, FinFETs and advanced MOSFET structures, relevant scaling issues in nanoscale devices, statistical variability, leakage currents.
Bipolar junction transistor (BJT)
 Basic structure of the device, working principles, current gain, collector current of the prototype transistor;
 Electric field in the quasineutral base region: nonuniform doping, high injection, bandgap narrowing and engineering of the base material, expressions for the collector current;
 Base current: shallow emitter and deep emitter;
 Dependence of the current gain of the transistor on the collector current, Gummel plot, carrier recombination in the base/emitter depletion layer, parasitic resistances, Kirk effect, modulation of the base conductivity;
 Currentvoltage characteristics of the BJT: saturation regime and forwardactive regime, Early effect;
 Smallsignal model of the BJT, frequency response, cutoff frequency and its dependence on the collector current, forward transit time;
 Evolution of device parameters, advanced device structures, polysilicon emitter, SiGe base.
