Boron gettering on cavities induced by helium implantation in Si

In this paper, we shed light on the strong interaction between the cavity l ayer induced by helium implantation and boron. First of all, we evidence th e impact of He gettering step on a boron-diffused profile. In order to stud y the boron-cavity interaction, we had used uniformly boron-doped wafers im planted with helium at high dose and anneal using usual furnace annealing ( FA) as well as rapid thermal annealing. Then, to avoid any precipitation ph enomena, conditions were chosen to not exceed the boron solid solubility va lue. Our experimental results exhibit a large trapping of boron within the cavity layer. This trapping occurs since the early stage of the annealing. These results enable us to have better understanding of this He gettering s tep as well as its interaction with boron atoms, which are of great interes t for device. (C) 2001 Elsevier Science B.V. All rights reserved.