Ex-situ n and p doping of vertical epitaxial short silicon nanowires by ion implantation


Ex-situ n and p doping of vertical epitaxial short silicon nanowires by ion implantation

Das Kanungo, P.; Kögler, R.; Nguyen-Duc, K.; Zhakarov, N.; Werner, P.; Gösele, U.

Epitaxial silicon nanowires (Si NWs) grown by molecular beam epitaxy on Si <111> substrates were separately doped p and n-type ex situ by implanting with B, P and As ions at room temperature with doses in the order of 1013 - 1014 cm-2. No implantation damage was observed in the B-implanted NWs after a rapid thermal annealing at 850°C for 30 s whereas the same could not heal out the P and As-implanted NWs completely. Electrical measurements showed that the desired doping concentrations were achieved for the B implanted NWs (p-type) while for the P and As implanted NWs (n-type) the measured carrier concentrations fell four orders of magnitude short of the intended. Incomplete electrical activation of the dopant atoms and out-diffusion/segregation at defects of dopants during annealing are probably responsible for such discrepancies in carrier concentrations in the n-type (P and As doped) NWs.

Keywords: Ion implantation; Doping; Si-nanowires

  • Nanotechnology 20(2009), 165706-165713

Permalink: https://www.hzdr.de/publications/Publ-12727
Publ.-Id: 12727