The Physics of Integrated Devices (2007/2008)

Learning outcomes

Aim of the course is to give knowledge of the physics of semiconductor devices (p-n junction, MOSFET, CMOS; BJT) and related logic gates. The student will be able to compare various logic families in terms of their physical characteristics and performances.

Useful physical concepts to recall: electric field, potential and potential energy, elementary charge, mass of atoms, electronvolt, electrical behavioiur of materials, temperature dependence of resistivity.

Brief introduction to quantum mechanics: quantization of light: black-body radiation, photoelectronic effect; quantization of matter: atomic emission and absorption spectra, Bohr atom, Stern-Gerlach experiment; wavelike behaviour of matter: De Broglie relation, uncertainty principle.

Crystal structure and electric conduction in metals and semiconductors: atomic structure and periodic table, electron gas model of metals, conduction current in metals; covalent bond in semiconductors and the concept of hole, conduction current in semiconductors; doped semiconductors; diffusion, Einstein relation, total current in semiconductors.

Hall effect

Band theory fundamentals: valence and conduction band, energy gap, materials classification and doped semiconductors according to band theory.

p-n junction: polarized and non polarized junction, I-V characteristics in direct and reverse polarization for Si and Ge, breakdown.

Junction diode: rectifier diodes, Zener diodes, OR/AND gates with diodes, commutation time.

Integrated circuits fabrication: diffusion, epythaxial growth, ionic implantation; steps of planar technology, photolithography.

FET transistors: enrichment and depletion MOSFET, NMOS and PMOS. MOSFET inverters; CMOS.

BJT transistors: common emitter configuration, RTL inverter; diodes, resistors and capacitors in integrated circuits.

Other semiconductor devices: CCD basic principles.

Elementary digital circuits: basic gates in MOS and bipolar technologies: NOR and NAND MOS, NOR and NAND CMOS, NAND DTL, NAND HTL, NAND TTL; OR/NOR ECL; comparison of logic families: propagation delay, power dissipation, noise margins, fan-out.

Oral exam.