Pulsed thermal annealing of ion-implanted silicon

Abstract

The use of a graphite strip heater to anneal implanted silicon has been investigated. The good electrical activity of an arsenic implanted layer obtained after annealing in this way is shown to degrade after simulated low temperature processing and lead to highly resistive layers. The annealing system has been used to reactivate such layers by employing high temperature thermal pulses of short duration which avoids excessive in-diffusion. The same annealing schedule has been used successfully to activate highly doped antimony, boron, and phosphorus layers. The importance of controlling the annealing ambient has also been studied and it is concluded that annealing in nitrogen avoids out-diffusion of dopant from the surface.