Controlled shallow single-ion implantation in silicon using an active substrate for sub-20-keV ions.

We demonstrate a method for the controlled implantation of single ions into a silicon substrate with energy of sub-20-keV. The method is based on the collection of electron-hole pairs generated in the substrate by the impact of a single ion. We have used the method to implant single 14-keV 31P ions through nanoscale masks into silicon as a route to the fabrication of devices based on single donors in silicon. [ABSTRACT FROM AUTHOR]