ENGINEERING TRIPOS PART IIA – 2012/2013

Module 3B5 – Semiconductor Engineering

COURSES

1.      Semiconductor Devices, weeks 1-4 (Dr Andrew Flewitt), weeks 5-8 (Dr. S. Hofmann).

AIMS

This course provides a framework of basic semiconductors physics to demonstrate how this aids the design process and helps in understanding, operation and performance limitations of devices in circuits and systems.

SYLLABUS

• Basic physics of semiconductors:  wave-particle duality, Schrodinger’s equation, E-k diagrams, energy bands, direct and indirect band gaps, density of states, Fermi level, intrinsic and extrinsic semiconductors, drift and diffusion, recombination and generation, continuity equation.
• p-n junctions band diagrams, junction in equilibrium, current flow in p-n junction, metal-semiconductor junctions, heterojunctions.
• The bipolar junction transistor (BJT), the heterojunction bipolar transistor (HBT), the junction field effect transitor (JFET), the metal semiconductor field effect transistor (MESFET), the high electron mobility transistor (HEMT) and the metal oxide semiconductor field effect transistor (MOSFET) - how they operate and I-V characteristrics.

OBJECTIVES

• Explain the concept of wave-particle duality especially with regard to electrons.
• Calculate allowed electron energy levels in single atoms from solutions of Schrodinger Equation, and be familiar with the concept of energy bands.
• Explain semiconductor behaviour in energy band and energy bond concepts.
• Be familiar with the idea of the Fermi Level, and the formation of n and p type semiconductors by the deliberate addition of dopant atoms.
• Apply the continuity equation to different semiconductor problems.
• Explain the formation of p-n junctions, and be familiar with how current flow across the junction is limited by minority carrier flow.
• Know how p-n junction formation can be used in the design of JFETs and bipolar transistors.
• Compare and contrast the performance of JFET and Bipolar Transistors.
• Know how metal semiconductor junctions can be used in the design of MESFETs and HEMTs, and be able to compare operation with that of the JFET.
• Explain the contrast the operating modes of the MOSFET, and be familiar with how device design affects I-V characteristics.
• Understand how MOSFETs may be utilised as simple memory devices.

REFERENCES

Please see the Booklist for Part IIA Courses for references for this module.