ABSTRACT

In more recent years, the concept of velocity overshoot in short-gate field-effect transistors has arisen as the technology has advanced sufficiently far to fabricate real devices with gate lengths as short as 20 nm. This has, in turn, focused attention on the short-time behavior of carriers subject to high electric fields. Unfortunately, it was almost impossible to study the time-dependent dynamics of these carriers due to the sub-picosecond relaxation times involved. However, the advent of modern femtosecond pulse-length lasers has opened a new area in which the actual temporal behavior can be observed, and this will be discussed in the next chapter. In