Local neutron transmutation doping using isotopically enriched silicon film

By means of thermal neutron irradiation on nanostructure fabricated from ³⁰Si-enriched material, the nanoregion can be selectively and homogeneously doped with ³¹P owing to the nuclear transmutation of ³⁰Si→³¹P (local neutron transmutation doping, NTD). In order to demonstrate the capability of local NTD, ³⁰Si-enriched silicon film is fabricated on p-Si(1 0 0) and irradiated by thermal neutrons. Upon the irradiation, film is n-doped while the substrate remains p-type, resulting in a formation of a p-n junction at film-substrate interface showing a rectification. This suggests strong possibility for application of the NTD for nano-scaled semiconductor devices.