High speed compound semiconductor devices

A Course to introduce underlying physical phenomena and principles of compound semiconductor devices  like Heterojunction Bipolar Transistors (HBT) and High Electron Mobility Transistors (HEMT).


Course Code:              EE7202

Credit Hours:                       3

EE6201 or instructor’s permission

Target Audience:
MS/PhD students wishing to pursue research in the field high-speed electronics, nanoelectronics, photovoltaic and its allied areas.

Figure 1 HBT epitaxial and geometrical structure



The explosive growth of low-power, high speed digital applications with data rates exceeding 40Gbps, broadband WLAN at 60 GHz and automotive radar systems at 77GHz  and other applications require devices with cut-off (fT) and maximum oscillation frequencies (fmax) much higher than 100 GHz. Compound semiconductor devices are considered to be one of the most competitive and suitable devices for such applications.
This course will extensively cover the comparison of Si-based devices with those based on compound semiconductors specifically III-Vs like GaAs, AlGaAs, InP and InGaAs. We will develop good understanding of a heterojunction, which is the fundamental underlying device structure of high speed devices like Heterojunction Bipolar Transistors (HBT) and High Electron Mobility Transistors (HEMT). HBT and HEMT are the compound semiconductor versions of BJTs and MOSFETs respectively. In this course we will further explore advanced device designs using custom and standard simulation/ modeling tools which may lead to some publishable research work.

Fig. 2 Agilent HBT large signal device model

M Mohiuddin did BE Electrical Engineering (EE) from NED University in 1992 and MS in EE from University of Nebraska, Lincoln, USA in 1996. He did his PhD in the area of compound semiconductor devices from The University of Manchester, UK in 2010. His current research interest include physical and empirical device modeling of InP Double Heterojunction Bipolar Transistors and High Electron Mobility Transistors for high speed, low-power digital applications.

Course Outline:


  1. Comparison of compound & elemental semiconductors
  2. Heterojunction—concept & its electrostatic analysis
  3. Heterojunction Bipolar Transistors (HBT)—construction, working principle, DC & AC analysis
  4. Comparative analysis of HBTs and HEMTs
  5. 2DEG (two dimensional electron gas)—the concept and its implementation in GaAs/AlGAs and other III-V material systems
  6. High Electron Mobility Transistors—construction, working principle, DC and AC analysis


Recommended Books:

  • P Robin and H Rohdin. High-speed heterostructure devices— 2002.
  • W Liu. Fundamentals of III-V devices— 1999.