Module IME-2009:
Microelectronics 2

Module Facts

Run by School of Computer Science and Electronic Engineering

10 Credits or 5 ECTS Credits

Semester 2

Organiser: Dr Mohammed Mabrook

Overall aims and purpose

To build on Microelectronics 1 (IME1009) to provide the basic elements of semiconductor physics necessary to understand the operation of semiconductor devices.

Course content

• Explanation of drift (mobility), diffusion and generation-recombination mechanisms

• Photoexcitation, equilibrium concentration of minority carriers and minority carrier lifetime. Steady state continuity equation leading to minority carrier diffusion length.

• The Haynes Shockley experiment and the Hall effect.

• Fabrication methods. Operation explained in terms of energy band diagrams. Application of the 1-d Poisson equation to the depletion region. Derivation of I-V characteristics of diode. Comparison of ideal and practical diodes.

• I-V characteristics of transistors. Large signal gain.

• Punch-through, avalanche and Zener breakdown processes. ESD protection.

• Band diagrams for ohmic and rectifying contacts. Role of metal work function. Achieving ohmic contacts to both n and p type silicon with only 1 metal. Schottky barrier diodes, solar cells.

• The MOS capacitor. The MOSFET.

Learning outcomes mapped to assessment criteria

  threshold

40%

good

60%

excellent

70%

Understand the origin of drift, diffusion and generation-recombination in semiconductor devices and critically evaluate their contributions to the total device current..

With guidance can derive mathematical expressions to describe the physical processes related to drift, diffusion and recombination of minority carriers. Understands the significance of the Haynes Shockley and Hall effect experiment. Can distinguish between the processes of drift and diffusion. Can define parameters such as minority carrier lifetime and diffusion length. Can outline the Haynes Shockley and Hall effect experiments From first principles, can derive expressions for carrier concentrat-ions and current flow in devices and is aware of the limitations of boundary conditions. Can relate the results of the Haynes-Shockley experiment to the operation of diodes and transistors.

Understand, explain and analyse the operation of pn junction diodes and bipolar transistors including device breakdown.

With guidance can derive equations describing the I-V characteristics of ideal diodes and bipolars. Can explain the physical processes leading to punch through, zener and avalanche breakdown. With guidance can derive equations from which breakdown voltages may be calculated. Can possibly explain the self-sustaining condition in bipolars. Can describe device fabrication steps based on planar technology. Can explain simply the microscopic processes underlying the operation of devices. Can integrate the 1-d Poisson equation to obtain fields/potentials. Can sketch the I-V characteristics of devices. Knows about the various breakdown mechanisms and their effect on device currents. Can derive expressions for current flow, fields and potentials in a pn junction diode. Can explain the departures from ideal behaviour seen in a real diode. Can design bipolars for high gain. Can derive and manipulate equations describing avalanche breakdown and punch through. Understands the links between device structure and breakdown.

Understand the important role of metal-semiconductor contacts.

Can explain the difference between an ohmic and rectifying contact. Aware of applications of Schottky diodes. Can confidently use band diagrams to explain ohmic and rectifying contacts. Can explain the operation of Schottky diode solar cells. Can relate theoretical concepts to practical implementation.

Understand and analyse the basic operation of MOS devices.

Can (a) identify key features and (b) describe operation of a MOSFET. Understands accumulation, depletion and inversion at a Si surface. With guidance can develop expressions for the I-V characteristics of an ideal MOSFET.

Assessment Methods

Type Name Description Weight
Examination 80
Quantitative question set 10
Technical report on plastic technology 10

Teaching and Learning Strategy

Hours
 

2 x 1 hour lecture slots over 12 weeks 4 Tutorials during lecture slots

24
Private study 76

Transferable skills

  • Numeracy - Proficiency in using numbers at appropriate levels of accuracy
  • Inter-personal - Able to question, actively listen, examine given answers and interact sensitevely with others
  • Critical analysis & Problem Solving - Able to deconstruct and analyse problems or complex situations. To find solutions to problems through analyses and exploration of all possibilities using appropriate methods, rescources and creativity.

Subject specific skills

  • Apply an understanding and appreciation of continuous improvement techniques

Pre- and Co-requisite Modules

Pre-requisite of:

Courses including this module