Charge Fluctuations in High-Electron-Mobility Transistors: A Review

The physics of high-electron-mobility transistors (HEMTs) plays a central role in contemporary design for millimetre-wave communications. HEMTs are the early fruits in a harvest of increasingly radical devices whose structural features are measured in nanometres. The operating principles of these devices are richly varied, and almost always far from classical. One of the tasks for device physics is to understand fluctuation phenomena, .or noise: the control of charge fluctuations is basic to high performance, yet the description of these processes remains incomplete if not obscure. This paper reviews some aspects of charge-transport noise that affect HEMT operation.