The Gentle Electronic Nature of Pulsed Beam Annealing, or Does It Really Go Superfluid?

Abstract

ABSTRACTUntil recently two theories of what may be occurring during pulsed laser/electron/ion beam annealing of Si, Ge, GaAs, and other semiconductors enjoyed credence. One held that the material became hot and underwent normal thermal melting. The other held that the material annealed in the presence of a hot dense plasma of excited free carriers, electrons and holes. A closer examination of previous experiments, as well as new experiments, particularly those of Marquardt et al., which indicate an absence of free carrier absorption in the infrared, make both these theories untenable. They also make possible a more sophisticated understanding of what really is happening. The present status of this subject is reviewed. In particular the available evidence that the plasma excited by the pulsed radiation undergoes a boson condensation to a superfluid phase is described.