• 097510 - PHYSICS OF SEMICONDUCTORS

The aim of this course is to describe some relevant aspects on the Physics of semiconductor devices and the limitations of them.

In particular, the characteristics of the more important semiconductor crystal structures will be presented. Some deposition techniques will be given, as well as information about the more common commercial substrates. In addition, some concepts on the diffusion of impurities and semiconductor alloys will be covered.
Several kind of crystalline defects will be presented for the more relevant semiconductor families. As well as, defects associated to the interfaces wil be also studied.
Finally, properties and characteristics of transparent oxides and semiconductors will presented taking into account the current and upcoming applications.

After completion of the course the students will know:
  i. the semiconductor structures and the fabrication and commercial aviability;
 ii. the limitations and tailoring of the semiconductors in term of defects and impurities;
iii. the new tendencies of the tradicional semiconductors, as well as the current and upcoming applicationstrans of transparent semiconductors and oxides.

Structural bulk properties
Crystal structure: lattice, important crystal structures (diamond, zinc-blende, amorphous semiconductors), crystal growth. Deposition techniques. Commercial substrates. Reciprocal space. Fermi surface: calculation and experimental determination. Solute and impurities diffusion. Semiconductor alloys.

Defects in semiconductors
Defects. Point defects: vacancies, Interstitials and substitutional atoms. Impurities. Experimental determinations. Dislocations: Burger vector, dislocation geometry (edge, screw, mixed, partial). Extended defects. Disorder. Shallow defects (Si, Ge and GaAs). Deep defects (Negative-U Center, EL2, DX). Jahn–Teller Effect. Surface charges and dipoles. Defects associated to the interfaces. Non-ideal p-n junction and metal/semiconductor interface (Schottky barrier).

Crystal structures and defects in transparent semiconductors
Structure, defects and properties of transparent oxides and semiconductors (GaN, ZnO and TiO2). Amorphous films (IGZO).  Current and upcoming applications: TFT transistors, displays, solar cells, etc.

The student will benefit of a background knowledge of solid state Physics and quantum mechanics.

Students will be evaluated by means of oral examination.

The oral exam is aimed at assessing the capability of the student to:

-describe semiconductor structures and fabrication methods;

-discuss the limitations and tailoring of the semiconductors in term of defects and impurities;

-be aware of new applications of  semiconductors, as well as of current and upcoming applications of transparent semiconductors and oxides.