Semiconductor Devices:

Semiconductor devices such like diodes, transistors and integrated circuits may be found everywhere in our daily lives, in televisions, music systems, washing machines, automobiles, computers, etc. The famous Moore's Law states that the transistor density of integrated circuits, w.r.t. minimum component cost, doubles every 24 months. It can be interpreted as the doubling of the number of transistors on integrated circuits (a rough measure of computer processing power) every 18 months. Such is the quick growth of semiconductor industry since the first invention of transistor in the year of 1947 by William Shockley, John Bardeen and Walter Brattain. Semiconductor devices are electronic devices that exploit the electronic properties of semiconductor materials, germanium, principally silicon and gallium arsenide. Therefore, it becomes a necessity for the future engineers to have a sound background on semiconductor physics and devices.

Objectives

After studying this unit, you should be able to

• Explain semiconductors in terms of energy band diagrams, differentiate between intrinsic and extrinsic semiconductors, describe n-type and p-type semiconductors,
• state the function of a diode, draw the I-V characteristics of a diode, understand the operation principle and application of Zener diodes,
• understand the operation of MOSFET , BJT, and JFET, draw the small signal equivalent circuits, and
• desribe the operating principles of Switches, TRIAC, SCR and IGBT.