It is the trend in the silicon and compound microelectronic technology to continuously develop semiconductor circuits which are faster, smaller, and consume less power for a similar level of integration. This has been recently fueled in part by the rapid growth of digital wireless communication, which relies on both low-power high-speed digital and high-frequency analog electronics. As part of this trend, microwave, RF and IF analog and digital circuits are being integrated in ‘mixed-signal’ circuits for wireless applications. Both silicon and compound state-of-the-art integrated circuits presently rely on high-speed state-of-the-art submicron devices. However, research in microelectronic technology is always expanding its frontier; new heterostructure semiconductor materials and devices are continuously being developed or improved in a process often referred to as bandgap engineering. These heterostructure devices, in particular, and high-speed devices, in general, constitute the subject of this book. In this book we take the readers on a journey providing them with an understanding of both fundamental and advanced device-physics concepts as well as introducing them to the development of realistic device models which can be used for the design, simulation and modeling of high-speed electronics.

The journey in this book takes the reader from the fundamental physical processes taking place in heterostructures to the practical issues involved in designing highperformance heterostructure devices.

Ever shrinking high-speed devices

It is a basic requirement that high-speed devices must be small. Reducing the device reduces the transit-time and the capacitances in devices. The operating voltage is also reduced, and this helps with the reduction of the power dissipation.