The influence of substrate temperature and the anneal ambient on the redistribution of arsenic implanted into silicon at ultra-low energy

The effects of implant temperature and anneal gas environment on the redistribution of arsenic implanted into silicon at 2.5 keV to high concentrations has been studied. The as-implanted damage structures were observed to be strongly dependent on implant temperature. The transient enhanced diffusion observed during 10 second anneals was found to be highly dependent on the presence of oxygen. When annealing was carried out in pure nitrogen, significant loss of dopant occurred and the TED was not dependent on implant temperature. In an environment containing oxygen, all the dopant was retained and more extensive, implant temperature dependent redistribution was observed.